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Sample records for understory herbaceous species

  1. Soil properties and understory herbaceous biomass in forests of three species of Quercus in Northeast Portugal

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    Marina Castro

    2014-12-01

    Full Text Available Aim of study: This paper aims to characterize some soil properties within the first 25 cm of the soil profile and the herbaceous biomass in Quercus forests, and the possible relationships between soil properties and understory standing biomass.Area of study: Three monoespecific Quercus forests (Q. suber L., Q. ilex subsp. rotundifolia Lam. and Q. pyrenaica Willd in NE Portugal.Material and methods: During 1999 and 2000 soil properties (pH-KCl, total soil nitrogen (N, soil organic carbon (SOC, C/N ratio, available phosphorus (P, and available potassium (K and herbaceous biomass production of three forest types: Quercus suber L., Quercus ilex subsp. rotundifolia Lam. and Quercus pyrenaica Willd were studied.Main results: The results showed a different pattern of soil fertility (N, SOC, P, K in Quercus forests in NE of Portugal. The C/N ratio and the herbaceous biomass confirmed this pattern. Research highlights: There is a pattern of Quercus sp. distribution that correlates with different soil characteristics by soil characteristics in NE Portugal. Q. pyrenaica ecosystems were found in more favoured areas (mesic conditions; Q. rotundifolia developed in nutrient-poor soils (oligotrophic conditions; and Q. suber were found in intermediate zones.Keywords: fertility; biomass; C/N ratio; cork oak; holm oak; pyrenean oak.

  2. Assessing tolerance of longleaf pine understory herbaceous plants to herbicide applications in a container nursery

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    D. Paul Jackson; Scott A. Enebak; James West; Drew Hinnant

    2015-01-01

    Renewed efforts in longleaf pine (Pinus palustris Mill.) ecosystem restoration has increased interest in the commercial production of understory herbaceous species. Successful establishment of understory herbaceous species is enhanced when using quality nursery-grown plants that have a better chance of survival after outplanting. Nursery growing practices have not been...

  3. Influence of tree species on the herbaceous understory and soil chemical characteristics in a silvopastoral system in semi-arid northeastern Brazil

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    R. S. C. Menezes

    1999-12-01

    Full Text Available Studies from some semi-arid regions of the world have shown the beneficial effect of trees in silvopastoral systems, by promoting the formation of resource islands and increasing the sustainability of the system. No data are available in this respect for tree species of common occurrence in semi-arid Northeastern Brazil. In the present study, conducted in the summer of 1996, three tree species (Zyziphus joazeiro, Spondias tuberosa and Prosopis juliflora: found within Cenchrus ciliaris pastures were selected to evaluate differences on herbaceous understory and soil chemical characteristics between samples taken under the tree canopy and in open grass areas. Transects extending from the tree trunk to open grass areas were established, and soil (0-15 cm and herbaceous understory (standing live biomass in 1 m² plots samples were taken at 0, 25, 50, 100, 150 and 200% of the average canopy radius (average radius was 6.6 ± 0.5, 4.5 ± 0.5, and 5.3 ± 0.8 m for Z. joazeiro, P. juliflora, and S. tuberosa , respectively. Higher levels of soil C, N, P, Ca, Mg, K, and Na were found under the canopies of Z. joazeiro and P. juliflora: trees, as compared to open grass areas. Only soil Mg organic P were higher under the canopies of S. tuberosa trees, as compared to open grass areas. Herbaceous understory biomass was significantly lower under the canopy of S. tuberosa and P. juliflora trees (107 and 96 g m-2, respectively relatively to open grass areas (145 and 194 g m-2. No herbaceous biomass differences were found between Z. joazeiro canopies and open grass areas (107 and 87 g m-2, respectively. Among the three tree species studied, Z. joazeiro was the one that presented the greatest potential for use in a silvopastoral system at the study site, since it had a larger nutrient stock in the soil without negatively affecting herbaceous understory biomass, relatively to open grass areas.

  4. Attempting to restore herbaceous understories in Wyoming big sagebrush communities with mowing and seeding

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    Shrub steppe communities with depleted perennial herbaceous understories need to be restored to increase resilience, provide quality wildlife habitat, and improve ecosystem function. Mowing has been applied to Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &Young) steppe...

  5. Above- and belowground competition from longleaf pine plantations limits performance of reintroduced herbaceous species.

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    T.B. Harrington; C.M. Dagley; M.B. Edwards.

    2003-10-01

    Although overstory trees limit the abundance and species richness of herbaceous vegetation in longleaf pine (Pinus palustris Mill.) plantations, the responsible mechanisms are poorly understood because of confounding among limiting factors. In fall 1998, research was initiated to determine the separate effects of above- and belowground competition and needlefall from overstory pines on understory plant performance. Three 13- to 15-yr-old plantations near Aiken, SC, were thinned to 0, 25, 50, or 100% of nonthinned basal area (19.5 m2 ha-1). Combinations of trenching (to eliminate root competition) and needlefall were applied to areas within each plot, and containerized seedlings of 14 perennial herbaceous species and longleaf pine were planted within each. Overstory crown closure ranged from 0 to 81%, and soil water and available nitrogen varied consistently with pine stocking, trenching, or their combination. Cover of planted species decreased an average of 16.5 and 14.1% as a result of above- and below-ground competition, respectively. Depending on species, needlefall effects were positive, negative, or negligible. Results indicate that understory restoration will be most successful when herbaceous species are established within canopy openings (0.1-0.2 ha) managed to minimize negative effects from above- and belowground competition and needlefall.

  6. Spatial Autocorrelation Patterns of Understory Plant Species in a Subtropical Rainforest at Lanjenchi, Southern Taiwan

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    Su-Wei Fan

    2010-06-01

    Full Text Available Many studies described relationships between plant species and intrinsic or exogenous factors, but few quantified spatial scales of species patterns. In this study, quantitative methods were used to explore the spatial scale of understory species (including resident and transient species, in order to identify the influential factors of species distribution. Resident species (including herbaceous species, climbers and tree ferns < 1 m high were investigated on seven transects, each 5-meter wide and 300-meter long, at Lanjenchi plot in Nanjenshan Reserve, southern Taiwan. Transient species (seedling of canopy, subcanopy and shrub species < 1 cm diameter at breast height were censused in three of the seven transects. The herb coverage and seedling abundance were calculated for each 5 × 5 m quadrat along the transects, and Moran’s I and Galiano’s new local variance (NLV indices were then used to identify the spatial scale of autocorrelation for each species. Patterns of species abundance of understory layer varied among species at fine scale within 50 meters. Resident species showed a higher proportion of significant autocorrelation than the transient species. Species with large size or prolonged fronds or stems tended to show larger scales in autocorrelation. However, dispersal syndromes and fruit types did not relate to any species’ spatial patterns. Several species showed a significant autocorrelation at a 180-meter class which happened to correspond to the local replicates of topographical features in hilltops. The spatial patterns of understory species at Lanjenchi plot are mainly influenced by species’ intrinsic traits and topographical characteristics.

  7. The legacy of deer overabundance: long-term delays in herbaceous understory recovery

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    Thomas H. Pendergast; Shane M. Hanlon; Zachary M. Long; Alex Royo; Walter P. Carson

    2016-01-01

    Decades of white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) overpopulation have dramatically homogenized forests across much of the eastern United States, creating depauperate forest understory communities. The rate at which these communities recover once deer browsing has been reduced remains an open question. We evaluate overbrowsing...

  8. PREDICTING FIELD PERFORMANCE OF HERBACEOUS SPECIES FOR PHYTOREMEDIATION OF PERCHLORATE

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    Results of these short-term experiments coupled with ecological knowledge of the nine herbaceous plant species tested suggest that several species may by successful in on-site remediation of perchlorate. The two wetland species which appear to be most suitable for field experimen...

  9. Ecophysiological responses of two herbaceous species to prescribed burning, alone or in combination with overstory thinning.

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    Huang, Jianjun; Boerner, Ralph E J; Rebbeck, Joanne

    2007-05-01

    The oak-rich deciduous forests of the central Appalachian Mountains of eastern North America have changed significantly since the onset of effective fire suppression early in the 20th century. Those changes have resulted in progressively decreasing light and nutrient supplies to herbaceous perennial understory species. Application of ecological restoration treatments such as reintroduction of frequent dormant-season fire and overstory thinning to pre-suppression density often increase light, soil temperature and moisture, and short-term nutrient availability to pre-suppression levels. To persist in this environment, perennial understory herbs must be able to acclimate phenotypically to the very different resource supply combinations present with and without fire suppression. As part of a larger study of the response of the long-lived herbaceous perennials Desmodium nudiflorum and Panicum boscii to ecosystem restoration treatments in Ohio mixed-oak forests, this study examined the ecophysiological effects of prescribed burning (B) and the combination of burning and thinning (T + B) in mixed-oak forests in southern Ohio. Control (C) plants had significantly lower maximum photosynthetic rate (A(max)) than those in the treated plots. The enhancement of A(max) averaged 26.7% and 52.7% in the B and T + B treatments, respectively. Plants from the T + B plots had higher quantum yield, stomatal conductance, and photosynthetic nutrient use efficiency than B and C plants. B plants had greater intrinsic water use efficiency (WUE) than plants in the C or T + B treatments. Light saturation point (LSP), light compensation point (LCP), and "dark" respiration (DR) did not differ among treatments. Photosynthetic parameters did vary significantly between the species, but no significant treatment × species interactions were detected. Our results support the hypothesis that prescribed burning, especially when combined with overstory thinning, in these perennial herbs can result in

  10. Species-specific associations between overstory and understory tree species in a semideciduous tropical forest

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    Flaviana Maluf Souza

    2015-03-01

    Full Text Available We investigated the occurrence of associations between overstory and understory tree species in a semideciduous tropical forest. We identified and measured all trees of nine canopy species with diameter at breast height ≥4.8 cm in a 10.24 ha plot and recorded all individuals beneath their canopies ("understory individuals" within the same diameter class. The total density of understory individuals did not significantly differ under different overstory species. One overstory species (Ceiba speciosa showed higher understory species richness compared with five other species. There was a strong positive association between three overstory species (Esenbeckia leiocarpa, Savia dictyocarpa, and C. speciosa and the density of seven understory species (Balfourodendron riedelianum, Chrysophyllum gonocarpum, E. leiocarpa, Holocalyx balansae, Machaerium stipitatum, Rhaminidium elaeocarpum, and S. dictyocarpa. These results probably reflect the outcome of a complex set of interactions including facilitation and competition, and further studies are necessary to better understand the magnitude and type of the effects of individual overstory species on understory species. The occurrence of species-specific associations shown here reinforces the importance of non-random processes in structuring plant communities and suggest that the influence of overstory species on understory species in high-diversity forests may be more significant than previously thought.

  11. Monoterpene emissions from an understory species, Pteridium aquilinum

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    Madronich, Monica B.; Greenberg, James P.; Wessman, Carol A.; Guenther, Alex B.

    2012-07-01

    Monoterpene emissions from the dominant understory species Pteridium aquilinum (Bracken fern) in a mixed temperate forest were measured in the field during the summers of 2006, 2007 and 2008. The results showed that Bracken fern emitted monoterpenes at different rates depending if the plants were located in the understory or in open areas. Understory plants emitted monoterpene levels ranging from 0.002 to 13 μgC gdw-1 h-1. Open area plants emitted monoterpene levels ranging from 0.005 to 2.21 μgC gdw-1 h-1. During the summer of 2008 greenhouse studies were performed to complement the field studies. Only 3% of the greenhouse Bracken fern plants emitted substantial amounts of monoterpenes. The average emission, 0.15 μgC gdw-1 h-1 ± 0.9 μgC gdw-1 h-1, was much lower than that observed in the field. The factors controlling monoterpene emissions are not clear, but this study provides evidence of the potential importance of understory vegetation to ecosystem total hydrocarbon emissions and emphasizes the need for longer-term field studies.

  12. Response of overstory and understory vegetation 37 years after prescribed burning in an aspen-dominated forest in northern Minnesota, USA – a case study

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    A. Dhar; C.D. Baker; H.B. Massicotte; Brian J. Palik; C.D.B. Hawkins

    2016-01-01

    Many studies have examined short-term changes in understory vegetation following prescribed burning. However, knowledge concerning longer term effects on both forest understory and overstory vegetation is lacking. This investigation was initiated to examine changes in understory (herbaceous and shrub) and overstory species composition almost four decades after logging...

  13. Simkin et al. 2016 PNAS data on herbaceous species richness and associated plot and covariate information

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    U.S. Environmental Protection Agency — This dataset includes the geographic location (lat/lon) for 15,136 plots, as well as the herbaceous species richness, climate, soil pH, and other variables related...

  14. Abundance of introduced species at home predicts abundance away in herbaceous communities

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    J. Firn; J.L. Moore; A.S. MacDougall; E.T. Borer; E.W. Seabloom; J. HilleRisLambers; S. Harpole; E.E. Cleland; C.S. Brown; J.M.H. Knops; S.M. Prober; D.A. Pyke; K.A. Farrell; J.D. Bakker; L.R. O’Halloran; P.B. Adler; S.L. Collins; C.M. D’Antonio; M.J. Crawley; E.M. Wolkovich; K.J. La Pierre; B.A. Melbourne; Y. Hautier; J.W. Morgan; A.D.B. Leakey; A.D. Kay; R.L. McCulley; K.F. Davies; C.J. Stevens; C.J. Chu

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at...

  15. Susceptibility to Phytophthora ramorum and inoculum production potential of some common eastern forest understory plant species

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    Paul W. Tooley; Marsha Browning

    2009-01-01

    Twenty-five plant species (21 genera, 14 families), which comprise a portion of the understory in forests of the Eastern United States, were evaluated for susceptibility to infection by Phytophthora ramorum. The degree to which P. ramorum is able to form sporangia and chlamydospores was also assessed on...

  16. Understory vegetation

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    Steve Sutherland; Todd F. Hutchinson; Jennifer L. Windus

    2003-01-01

    This chapter documents patterns of species composition and diversity within the understory vegetation layer and provides a species list for the four study areas in southern Ohio. Within each of 108 plots, we recorded the frequency of all vascular plant species in sixteen 2-m² quadrats. We recorded 297 species, including 187 forbs (176 perennials, 9 annuals, 2...

  17. Intraspecific variability and reaction norms of forest understory plant species traits

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    Burton, Julia I.; Perakis, Steven; McKenzie, Sean C.; Lawrence, Caitlin E.; Puettmann, Klaus J.

    2017-01-01

    Trait-based models of ecological communities typically assume intraspecific variation in functional traits is not important, though such variation can change species trait rankings along gradients in resources and environmental conditions, and thus influence community structure and function.We examined the degree of intraspecific relative to interspecific variation, and reaction norms of 11 functional traits for 57 forest understory plant species, including: intrinsic water-use efficiency (iWUE), Δ15N, 5 leaf traits, 2 stem traits and 2 root traits along gradients in light, nitrogen, moisture and understory cover.Our results indicate that interspecific trait variation exceeded intraspecific variation by at least 50% for most, but not all traits. Intraspecific variation in Δ15N, iWUE, leaf nitrogen content and root traits was high (47-70%) compared with most leaf traits and stem traits (13-38%).Δ15N varied primarily along gradients in abiotic conditions, while light and understory cover were relatively less important. iWUE was related primarily to light transmission, reflecting increases in photosynthesis relative to stomatal conductance. Leaf traits varied mainly as a function of light availability, with some reaction norms depending on understory cover. Plant height increased with understory cover, while stem specific density was related primarily to light. Resources, environmental conditions and understory cover did not contribute strongly to the observed variation in root traits.Gradients in resources, environmental conditions and competition all appear to control intraspecific variability in most traits to some extent. However, our results suggest that species cross-over (i.e., trait rank reversals) along the gradients measured here are generally not a concern.Intraspecific variability in understory plant species traits can be considerable. However, trait data collected under a narrow range of environmental conditions appears sufficient to establish species

  18. Phyllanthus coi (Phyllanthaceae, a new herbaceous species from the Philippines

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    Ming-Jou WU

    2017-11-01

    Full Text Available Phyllanthus coi M.J. Wu, Ferreras & Y.J. Chen, a new species from Benguet Province, Island of Luzon, the Philippines, is described and illustrated. Compared to its congeners in the same section, P. coi can be differentiated by having long plagiotropic branchlets with up to 30 leaves per side, seeds with sharp honey-comb-like ridges on the dorsal side, and three free styles that are not lying flat on the top of the ovary. The floral, seed and some vegetative features that distinguish this new species from its nearest morphologically related species, P. erythrotrichus C.B. Rob., P. urinaria L. and P. hookeri Müll. Arg. are provided.

  19. Large herbivores maintain termite-caused differences in herbaceous species diversity patterns.

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    Okullo, Paul; Moe, Stein R

    2012-09-01

    Termites and large herbivores affect African savanna plant communities. Both functional groups are also important for nutrient redistribution across the landscape. We conducted an experiment to study how termites and large herbivores, alone and in combination, affect herbaceous species diversity patterns in an African savanna. Herbaceous vegetation on large vegetated Macrotermes mounds (with and without large herbivores) and on adjacent savanna areas (with and without large herbivores) was monitored over three years in Lake Mburo National Park, Uganda. We found substantial differences in species richness, alpha diversity, evenness, and stability between termite mound herbaceous vegetation and adjacent savanna vegetation. Within months of fencing, levels of species richness, evenness, and stability were no longer significantly different between savanna and mounds. However, fencing reduced the cumulative number of species, particularly for forbs, of which 48% of the species were lost. Fencing increased the beta diversity (dissimilarity among plots) on the resource-poor (in terms of both nutrients and soil moisture) savanna areas, while it did not significantly affect beta diversity on the resource-rich termite mounds. While termites cause substantial heterogeneity in savanna vegetation, large herbivores further amplify these differences by reducing beta diversity on the savanna areas. Large herbivores are, however, responsible for the maintenance of a large number of forbs at the landscape level. These findings suggest that the mechanisms underlying the effects of termites and large herbivores on savanna plant communities scale up to shape community structure and dynamics at a landscape level.

  20. Understory succession in post-agricultural oak plantations

    DEFF Research Database (Denmark)

    Brunet, Jörg; Valtinat, Karin; Mayr, Marian Lajos

    2011-01-01

    The herbaceous understory forms the richest stratum in temperate broadleaved forests in terms of plant diversity. Understanding the process of understory succession is thus of critical importance for the development of management guidelines for biodiversity restoration in post-agricultural planta......The herbaceous understory forms the richest stratum in temperate broadleaved forests in terms of plant diversity. Understanding the process of understory succession is thus of critical importance for the development of management guidelines for biodiversity restoration in post...... forested stands, which maintained differences in species composition. The development of a shrub layer seemed to imply a competitive advantage for forest specialists compared to generalist species. For successful recovery of a rich understory, we suggest that post-arable plantations should be established......, and woody species. The group of forest specialists may approach the richness of continuously forested sites after 60-80 years in non-fragmented plantations, but many forest species were sensitive to habitat fragmentation. Open-land species richness decreased during succession, while the richness of woody...

  1. Assessing radiation exposure of herbaceous plant species at the East-Ural Radioactive Trace

    International Nuclear Information System (INIS)

    Karimullina, Elina; Antonova, Elena; Pozolotina, Vera

    2013-01-01

    The East-Ural Radioactive Trace (EURT) is a result of the Mayak Production Association accident that occurred in 1957 in Russia. Radiological assessment improves the interpretation of biological effects of exposure to ionizing radiation. Therefore a modeling approach was used to estimate dose rates on Leonurus quinquelobatus, Silene latifolia, Stellaria graminea and Bromus inermis. Soil-to-organism transfer parameter values are delivered from empirical data of 90 Sr and 137 Cs soil and vegetative plant mass activity concentrations. External and internal whole-body dose rates were calculated using deterministic (The ERICA Tool-Tier 2 and R and D 128/SP1a) and probabilistic (The ERICA Tool-Tier 3) methods. The total dose rate for herbs was under 100 μGy h −1 at the most polluted site. The total absorbed dose rates increased 43–110 times (Tier 3) for different herbaceous plant species along the pollution gradient. Based on these data, it can be concluded that herbaceous plant populations currently exist under low-level chronic exposure at the EURT area. -- Highlights: • A modeling approach (The ERICA Tool-Tier 2, Tier 3 and R and D 128/SP1a) was used to estimate dose rates for herbs growing in the wild at the East-Ural Radioactive Trace. • The highest levels of anthropogenic radiation exposure were determined for herbs at Impact EURT sites. • Total absorbed dose rates increased 43–110 times (Tier 3) for different herbaceous plant species along the pollution gradient. • Total dose rate per plant organism for herbs is under 100 μGy h −1 at the most polluted site. Currently herbaceous plant populations exist under low-level chronic exposure at the EURT area

  2. Abundance of introduced species at home predicts abundance away in herbaceous communities

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    Firn, Jennifer; Moore, Joslin L.; MacDougall, Andrew S.; Borer, Elizabeth T.; Seabloom, Eric W.; HilleRisLambers, Janneke; Harpole, W. Stanley; Cleland, Elsa E.; Brown, Cynthia S.; Knops, Johannes M.H.; Prober, Suzanne M.; Pyke, David A.; Farrell, Kelly A.; Bakker, John D.; O'Halloran, Lydia R.; Adler, Peter B.; Collins, Scott L.; D'Antonio, Carla M.; Crawley, Michael J.; Wolkovich, Elizabeth M.; La Pierre, Kimberly J.; Melbourne, Brett A.; Hautier, Yann; Morgan, John W.; Leakey, Andrew D.B.; Kay, Adam; McCulley, Rebecca; Davies, Kendi F.; Stevens, Carly J.; Chu, Cheng-Jin; Holl, Karen D.; Klein, Julia A.; Fay, Phillip A.; Hagenah, Nicole; Kirkman, Kevin P.; Buckley, Yvonne M.

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.

  3. Woody-Herbaceous Species Coexistence in Mulga Hillslopes: Modelling Structure and Function

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    Soltanjalili, M. J.; Saco, P. M.; Willgoose, G. R.

    2016-12-01

    The fundamental processes underlying the coexistence of woody and herbaceous species in arid and semi-arid areas have been a topic of intense research during the last few decades. Experimental and modelling studies have both supported and disputed alternative hypotheses explaining this phenomenon. Vegetation models including the key processes that drive coexistence can be used to understand vegetation pattern dynamics and structure under current climate conditions, and to predict changes under future conditions. Here we present work done towards linking the observations to modelling. The model captures woody-herbaceous coexistence along a rainfall gradient characteristic of typical conditions on Mulga ecosystems in Australia. The dynamic vegetation model simulates the spatial dynamics of overland flow, soil moisture and vegetation growth of two species. It incorporates key mechanisms for coexistence and pattern formation, including facilitation by evaporation reduction through shading, and infiltration feedbacks, local and non-local seed dispersal, competition for water uptake. Model outcomes, obtained including diflerent mechanisms, are qualitatively compared to typical vegetation cover patterns in the Australian Mulga bioregion where bush fire is very infrequent and the fate of vegetation cover is mostly determined by intra- and interspecies interactions. Through these comparisons, and by drawing on the large number of recent studies that have delivered new insights into the dynamics of such ecosystems, we identify main mechanisms that need an improved representation in the dynamic vegetation models. We show that a realistic parameterization of the model leads to results which are aligned with the observations reported in the literature. At the lower end of the rainfall gradient woody species coexist with herbaceous species within a sparse banded pattern, while at higher rainfall woody species tend to dominate the landscape.

  4. Photosynthetic responses to understory shade and elevated carbon dioxide concentration in 4 northern hardwood tree species

    International Nuclear Information System (INIS)

    Sefcik, L.T.; Zak, D.R.; Ellsworth, D.S.

    2006-01-01

    Stimulation of photosynthesis in response to elevated carbon dioxide (CO 2 ) varies among tree species and species groups. In this study, seedling responses to elevated atmospheric carbon dioxide (CO 2 ) concentrations and solar irradiance over 2 growing seasons were investigated for shade tolerant Acer saccharum Marsh.; Fagus grandifolia J.F. Ehrh; and shade-intolerant Prunus serotina. Seedlings were exposed to a combination of elevated and ambient concentrations of CO 2 and understory shade in open-top chambers placed in a forest understory. It was observed that the elevated CO 2 treatment increased mean light-saturated net photosynthetic rates by 63 per cent in the shade-tolerant species and 67 per cent in the shade-intolerant species. When measured at the elevated CO 2 , long-term enhancement of photosynthesis was 10 per cent lower than the instantaneous enhancement observed in ambient-CO 2 -grown plants. As the growth irradiance increased, proportional enhancement due to elevated CO 2 decreased from 97 per cent for plants grown in deep shade to 47 per cent for plants grown in moderate shade. Results indicated that in nitrogen (N) limited northern temperate forests, trees grown in deep shade may display greater photosynthetic gains from a CO 2 enriched atmosphere than trees growing in more moderate shade, due to greater down-regulation. It was concluded that if elevated CO 2 levels promote the survival of shade-intolerant species in dim understory light, the future composition and dynamics of successional forest communities may be altered. 70 refs., 2 tabs., 3 figs

  5. Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

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    Rueda, Marta; Moreno Saiz, Juan Carlos; Morales-Castilla, Ignacio; Albuquerque, Fabio S; Ferrero, Mila; Rodríguez, Miguel Á

    2015-01-01

    Ecological theory predicts that fragmentation aggravates the effects of habitat loss, yet empirical results show mixed evidences, which fail to support the theory instead reinforcing the primary importance of habitat loss. Fragmentation hypotheses have received much attention due to their potential implications for biodiversity conservation, however, animal studies have traditionally been their main focus. Here we assess variation in species sensitivity to forest amount and fragmentation and evaluate if fragmentation is related to extinction thresholds in forest understory herbs and ferns. Our expectation was that forest herbs would be more sensitive to fragmentation than ferns due to their lower dispersal capabilities. Using forest cover percentage and the proportion of this percentage occurring in the largest patch within UTM cells of 10-km resolution covering Peninsular Spain, we partitioned the effects of forest amount versus fragmentation and applied logistic regression to model occurrences of 16 species. For nine models showing robustness according to a set of quality criteria we subsequently defined two empirical fragmentation scenarios, minimum and maximum, and quantified species' sensitivity to forest contraction with no fragmentation, and to fragmentation under constant forest cover. We finally assessed how the extinction threshold of each species (the habitat amount below which it cannot persist) varies under no and maximum fragmentation. Consistent with their preference for forest habitats probability occurrences of all species decreased as forest cover contracted. On average, herbs did not show significant sensitivity to fragmentation whereas ferns were favored. In line with theory, fragmentation yielded higher extinction thresholds for two species. For the remaining species, fragmentation had either positive or non-significant effects. We interpret these differences as reflecting species-specific traits and conclude that although forest amount is of

  6. Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

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    Marta Rueda

    Full Text Available Ecological theory predicts that fragmentation aggravates the effects of habitat loss, yet empirical results show mixed evidences, which fail to support the theory instead reinforcing the primary importance of habitat loss. Fragmentation hypotheses have received much attention due to their potential implications for biodiversity conservation, however, animal studies have traditionally been their main focus. Here we assess variation in species sensitivity to forest amount and fragmentation and evaluate if fragmentation is related to extinction thresholds in forest understory herbs and ferns. Our expectation was that forest herbs would be more sensitive to fragmentation than ferns due to their lower dispersal capabilities. Using forest cover percentage and the proportion of this percentage occurring in the largest patch within UTM cells of 10-km resolution covering Peninsular Spain, we partitioned the effects of forest amount versus fragmentation and applied logistic regression to model occurrences of 16 species. For nine models showing robustness according to a set of quality criteria we subsequently defined two empirical fragmentation scenarios, minimum and maximum, and quantified species' sensitivity to forest contraction with no fragmentation, and to fragmentation under constant forest cover. We finally assessed how the extinction threshold of each species (the habitat amount below which it cannot persist varies under no and maximum fragmentation. Consistent with their preference for forest habitats probability occurrences of all species decreased as forest cover contracted. On average, herbs did not show significant sensitivity to fragmentation whereas ferns were favored. In line with theory, fragmentation yielded higher extinction thresholds for two species. For the remaining species, fragmentation had either positive or non-significant effects. We interpret these differences as reflecting species-specific traits and conclude that although

  7. Phenology of selected herbaceous species of northern Wisconsin deciduous forests and forest roads

    International Nuclear Information System (INIS)

    Zavitkovski, J.

    1977-01-01

    Vegetative and reproductive phenophases were observed from 1970 to 1974 on 30 native and 8 introduced herbaceous species growing under deciduous forests and on an abandoned logging road in the Enterprise Radiation Forest in northern Wisconsin. Forest herbs started growing in the same order each year, but logging-road herbs varied. Growth initiation was more variable in the early-starting than in the late-starting species. In most years logging-road herbs started growth a few days earlier than forest herbs. Initiation of flowering of the 38 species was bimodal, culminating around mid-May for forest species and around mid-July for logging-road species. In general, the annual start of flowering varied less than the start of vegetative growth. Duration of flowering of most species was variable, however. Seed ripening times varied strikingly among species, ranging from 11 days for Taraxacum officinale to 101 days for Iris versicolor. Seeds of forest herbs took longer to ripen than those of logging-road species. On the basis of growth initiation of the 6 earliest species, spring arrival in 1970 to 1974 differed by 26 days and appeared to be related to snow disappearance. The growing season of most species paralleled cumulative current-year (May--July) and last-year (August--September) precipitation. Multiple regression analyses between precipitation and average length of growing season explained 87 percent of the total variation for forest herbs and 69 percent of that for logging-road herbs

  8. Short-term light and leaf photosynthetic dynamics affect estimates of daily understory photosynthesis in four tree species.

    Science.gov (United States)

    Naumburg, Elke; Ellsworth, David S

    2002-04-01

    Instantaneous measurements of photosynthesis are often implicitly or explicitly scaled to longer time frames to provide an understanding of plant performance in a given environment. For plants growing in a forest understory, results from photosynthetic light response curves in conjunction with diurnal light data are frequently extrapolated to daily photosynthesis (A(day)), ignoring dynamic photosynthetic responses to light. In this study, we evaluated the importance of two factors on A(day) estimates: dynamic physiological responses to photosynthetic photon flux density (PPFD); and time-resolution of the PPFD data used for modeling. We used a dynamic photosynthesis model to investigate how these factors interact with species-specific photosynthetic traits, forest type, and sky conditions to affect the accuracy of A(day) predictions. Increasing time-averaging of PPFD significantly increased the relative overestimation of A(day) similarly for all study species because of the nonlinear response of photosynthesis to PPFD (15% with 5-min PPFD means). Depending on the light environment characteristics and species-specific dynamic responses to PPFD, understory tree A(day) can be overestimated by 6-42% for the study species by ignoring these dynamics. Although these overestimates decrease under cloudy conditions where direct sunlight and consequently understory sunfleck radiation is reduced, they are still significant. Within a species, overestimation of A(day) as a result of ignoring dynamic responses was highly dependent on daily sunfleck PPFD and the frequency and irradiance of sunflecks. Overall, large overestimates of A(day) in understory trees may cause misleading inferences concerning species growth and competition in forest understories with sunlight. We conclude that comparisons of A(day) among co-occurring understory species in deep shade will be enhanced by consideration of sunflecks by using high-resolution PPFD data and understanding the physiological

  9. Forest soil CO2 fluxes as a function of understory removal and N-fixing species addition.

    Science.gov (United States)

    Li, Haifang; Fu, Shenglei; Zhao, Hongting; Xia, Hanping

    2011-01-01

    We report on the effects of forest management practices of understory removal and N-fixing species (Cassia alata) addition on soil CO2 fluxes in an Eucalyptus urophylla plantation (EUp), Acacia crassicarpa plantation (ACp), 10-species-mixed plantation (Tp), and 30-species-mixed plantation (THp) using the static chamber method in southern China. Four forest management treatments, including (1) understory removal (UR); (2) C. alata addition (CA); (3) understory removal and replacement with C. alata (UR+CA); and (4) control without any disturbances (CK), were applied in the above four forest plantations with three replications for each treatment. The results showed that soil CO2 fluxes rates remained at a high level during the rainy season (from April to September), followed by a rapid decrease after October reaching a minimum in February. Soil CO2 fluxes were significantly higher (P plantations under various management practices.

  10. Effects of Dichrostachys cinerea (l. Wight & Arn (Fabaceae on herbaceous species in a semi-arid rangeland in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Clarice Mudzengi

    2014-08-01

    Full Text Available Anthropogenic alteration of an environment and other disturbance regimes may enable the expansion of some native species into new geographical areas, a phenomenon observed with Dichrostachys cinerea. Five D. cinerea invaded sites, each approximately one hectare in size were assessed for the effects of D. cinerea on native herbaceous species diversity, richness, basal cover, litter cover, top hamper and plant vigour. The same attributes were studied in five uninvaded sites adjacent to, and equal in size to each invaded site. Forty herbaceous species were identified in the area. There were significant differences (P < 0.05 noted in species richness, basal cover, litter cover, top hamper, plant vigour, and species diversities between invaded and uninvaded sites, with uninvaded sites recording higher values than invaded sites. Altitude, erosion and the edaphic variables pH, N, P and K, which were included as explanatory variables, also differed significantly (P<0.05 between invaded and uninvaded sites. Of the 30 D. cinerea invaded plots established for herbaceous species assessments, 26 were positively correlated with altitude, erosion, pH, P, N and K. It is imperative to find ways of managing D. cinerea in order to reduce its adverse effects on herbaceous species.

  11. Traits and climate are associated with first flowering day in herbaceous species along elevational gradients.

    Science.gov (United States)

    Bucher, Solveig Franziska; König, Patrizia; Menzel, Annette; Migliavacca, Mirco; Ewald, Jörg; Römermann, Christine

    2018-01-01

    Phenological responses to changing temperatures are known as "fingerprints of climate change," yet these reactions are highly species specific. To assess whether different plant characteristics are related to these species-specific responses in flowering phenology, we observed the first flowering day (FFD) of ten herbaceous species along two elevational gradients, representing temperature gradients. On the same populations, we measured traits being associated with (1) plant performance (specific leaf area), (2) leaf biochemistry (leaf C, N, P, K, and Mg content), and (3) water-use efficiency (stomatal pore area index and stable carbon isotopes concentration). We found that as elevation increased, FFD was delayed for all species with a highly species-specific rate. Populations at higher elevations needed less temperature accumulation to start flowering than populations of the same species at lower elevations. Surprisingly, traits explained a higher proportion of variance in the phenological data than elevation. Earlier flowering was associated with higher water-use efficiency, higher leaf C, and lower leaf P content. In addition to that, the intensity of shifts in FFD was related to leaf N and K. These results propose that traits have a high potential in explaining phenological variations, which even surpassed the effect of temperature changes in our study. Therefore, they have a high potential to be included in future analyses studying the effects of climate change and will help to improve predictions of vegetation changes.

  12. The factors controlling species density in herbaceous plant communities: An assessment

    Science.gov (United States)

    Grace, J.B.

    1999-01-01

    This paper evaluates both the ideas and empirical evidence pertaining to the control of species density in herbaceous plant communities. While most theoretical discussions of species density have emphasized the importance of habitat productivity and disturbance regimes, many other factors (e.g. species pools, plant litter accumulation, plant morphology) have been proposed to be important. A review of literature presenting observations on the density of species in small plots (in the vicinity of a few square meters or less), as well as experimental studies, suggests several generalizations: (1) Available data are consistent with an underlying unimodal relationship between species density and total community biomass. While variance in species density is often poorly explained by predictor variables, there is strong evidence that high levels of community biomass are antagonistic to high species density. (2) Community biomass is just one of several factors affecting variations in species density. Multivariate analyses typically explain more than twice as much variance in species density as can be explained by community biomass alone. (3) Disturbance has important and sometimes complex effects on species density. In general, the evidence is consistent with the intermediate disturbance hypothesis but exceptions exist and effects can be complex. (4) Gradients in the species pool can have important influences on patterns of species density. Evidence is mounting that a considerable amount of the observed variability in species density within a landscape or region may result from environmental effects on the species pool. (5) Several additional factors deserve greater consideration, including time lags, species composition, plant morphology, plant density and soil microbial effects. Based on the available evidence, a conceptual model of the primary factors controlling species density is presented here. This model suggests that species density is controlled by the effects of

  13. Horticultural markets promote alien species invasions: an Estonian case study of herbaceous perennials

    Directory of Open Access Journals (Sweden)

    Merle Ööpik

    2013-06-01

    Full Text Available Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.

  14. Resource Limitations Influence Growth and Vigor of Idaho Fescue, a Common Understory Species in Pacific Northwest Ponderosa Pine Forests

    Directory of Open Access Journals (Sweden)

    Craig A. Carr

    2016-12-01

    Full Text Available Alterations in under-canopy resource availability associated with elevated ponderosa pine (Pinus ponderosa Dougl. abundance can negatively influence understory vegetation. Experimental evidence linking under-canopy resource availability and understory vegetation is scarce. Yet this information would be beneficial in developing management strategies to recover desired understory species. We tested the effects of varying nitrogen (N and light availability on Idaho fescue (Festuca idahoensis Elmer, the dominant understory species in ponderosa pine/Idaho fescue plant associations in eastern Oregon. In a greenhouse experiment, two levels of N (50 kg∙N∙ha−1 and 0 kg∙N∙ha−1 and shade (80% shade and 0% shade were applied in a split-plot design to individual potted plants grown in soil collected from high abundance pine stands. Plants grown in unshaded conditions produced greater root (p = 0.0027 and shoot (p = 0.0017 biomass and higher cover values (p = 0.0378 compared to those in the shaded treatments. The addition of N had little effect on plant growth (p = 0.1602, 0.5129, and 0.0853 for shoot biomass, root biomass, and cover, respectively, suggesting that soils in high-density ponderosa pine stands that lack understory vegetation were not N deficient and Idaho fescue plants grown in these soils were not N limited. Management activities that increase under-canopy light availability will promote the conditions necessary for Idaho fescue recovery. However, successful restoration may be constrained by a lack of residual fescue or the invasion of more competitive understory vegetation.

  15. Rapid Increases in forest understory diversity and productivity following a mountain pine beetle (Dendroctonus ponderosae outbreak in pine forests.

    Directory of Open Access Journals (Sweden)

    Gregory J Pec

    Full Text Available The current unprecedented outbreak of mountain pine beetle (Dendroctonus ponderosae in lodgepole pine (Pinus contorta forests of western Canada has resulted in a landscape consisting of a mosaic of forest stands at different stages of mortality. Within forest stands, understory communities are the reservoir of the majority of plant species diversity and influence the composition of future forests in response to disturbance. Although changes to stand composition following beetle outbreaks are well documented, information on immediate responses of forest understory plant communities is limited. The objective of this study was to examine the effects of D. ponderosae-induced tree mortality on initial changes in diversity and productivity of understory plant communities. We established a total of 110 1-m2 plots across eleven mature lodgepole pine forests to measure changes in understory diversity and productivity as a function of tree mortality and below ground resource availability across multiple years. Overall, understory community diversity and productivity increased across the gradient of increased tree mortality. Richness of herbaceous perennials increased with tree mortality as well as soil moisture and nutrient levels. In contrast, the diversity of woody perennials did not change across the gradient of tree mortality. Understory vegetation, namely herbaceous perennials, showed an immediate response to improved growing conditions caused by increases in tree mortality. How this increased pulse in understory richness and productivity affects future forest trajectories in a novel system is unknown.

  16. Rapid Increases in forest understory diversity and productivity following a mountain pine beetle (Dendroctonus ponderosae) outbreak in pine forests.

    Science.gov (United States)

    Pec, Gregory J; Karst, Justine; Sywenky, Alexandra N; Cigan, Paul W; Erbilgin, Nadir; Simard, Suzanne W; Cahill, James F

    2015-01-01

    The current unprecedented outbreak of mountain pine beetle (Dendroctonus ponderosae) in lodgepole pine (Pinus contorta) forests of western Canada has resulted in a landscape consisting of a mosaic of forest stands at different stages of mortality. Within forest stands, understory communities are the reservoir of the majority of plant species diversity and influence the composition of future forests in response to disturbance. Although changes to stand composition following beetle outbreaks are well documented, information on immediate responses of forest understory plant communities is limited. The objective of this study was to examine the effects of D. ponderosae-induced tree mortality on initial changes in diversity and productivity of understory plant communities. We established a total of 110 1-m2 plots across eleven mature lodgepole pine forests to measure changes in understory diversity and productivity as a function of tree mortality and below ground resource availability across multiple years. Overall, understory community diversity and productivity increased across the gradient of increased tree mortality. Richness of herbaceous perennials increased with tree mortality as well as soil moisture and nutrient levels. In contrast, the diversity of woody perennials did not change across the gradient of tree mortality. Understory vegetation, namely herbaceous perennials, showed an immediate response to improved growing conditions caused by increases in tree mortality. How this increased pulse in understory richness and productivity affects future forest trajectories in a novel system is unknown.

  17. Phytoextraction of rare earth elements in herbaceous plant species growing close to roads.

    Science.gov (United States)

    Mikołajczak, Patrycja; Borowiak, Klaudia; Niedzielski, Przemysław

    2017-06-01

    The aim of study was to determine the phytoextraction of rare earth elements (REEs) to roots, stems and leaves of five herbaceous plant species (Achillea millefolium L., Artemisia vulgaris L., Papaver rhoeas L., Taraxacum officinale AND Tripleurospermum inodorum), growing in four areas located in close proximity to a road with varied traffic intensity. Additionally, the relationship between road traffic intensity, REE concentration in soil and the content of these elements in plant organs was estimated. A. vulgaris and P. rhoeas were able to effectively transport REEs in their leaves, independently of area collection. The highest content of REEs was observed in P. rhoeas leaves and T. inodorum roots. Generally, HREEs were accumulated in P. rhoeas roots and leaves and also in the stems of T. inodorum and T. officinale, whereas LREEs were accumulated in T. inodorum roots and T. officinale stems. It is worth underlining that there was a clear relationship between road traffic intensity and REE, HREE and LREE concentration in soil. No positive correlation was found between the concentration of these elements in soil and their content in plants, with the exception of T. officinale. An effective transport of REEs from the root system to leaves was observed, what points to the possible ability of some of the tested plant species to remove REEs from soils near roads.

  18. THE CANOPY EFFECTS OF Prosopis juliflora (DC. AND Acacia tortilis (HAYNE TREES ON HERBACEOUS PLANTS SPECIES AND SOIL PHYSICO-CHEMICAL PROPERTIES IN NJEMPS FLATS, KENYA

    Directory of Open Access Journals (Sweden)

    Henry C. Kahi

    2009-03-01

    Full Text Available The canopy effects of an exotic and indigenous tree species on soil properties and understorey herbaceous plant species were investigated on the Njemps Flats, Baringo district, Kenya. Samples of soil and herbaceous plant species were obtained within the canopies of systematically selected P. juliflora (exotic and A. tortilis (indigenous trees, and from adjacent open areas. Standing biomass, frequency and cover of understorey plant species were significantly (P

  19. Management of Herbaceous Seeps and Wet Savannas for Threatened and Endangered Species

    National Research Council Canada - National Science Library

    Harper, Mary

    1998-01-01

    Wetland communities such as herbaceous seeps and wet savannas occur on military installations throughout the southeastern United States, usually as pockets of wet habitat within a matrix of drier longleaf pine woodlands...

  20. Fine-spatial scale predictions of understory species using climate- and LiDAR-derived terrain and canopy metrics

    Science.gov (United States)

    Nijland, Wiebe; Nielsen, Scott E.; Coops, Nicholas C.; Wulder, Michael A.; Stenhouse, Gordon B.

    2014-01-01

    Food and habitat resources are critical components of wildlife management and conservation efforts. The grizzly bear (Ursus arctos) has diverse diets and habitat requirements particularly for understory plant species, which are impacted by human developments and forest management activities. We use light detection and ranging (LiDAR) data to predict the occurrence of 14 understory plant species relevant to bear forage and compare our predictions with more conventional climate- and land cover-based models. We use boosted regression trees to model each of the 14 understory species across 4435 km2 using occurrence (presence-absence) data from 1941 field plots. Three sets of models were fitted: climate only, climate and basic land and forest covers from Landsat 30-m imagery, and a climate- and LiDAR-derived model describing both the terrain and forest canopy. Resulting model accuracies varied widely among species. Overall, 8 of 14 species models were improved by including the LiDAR-derived variables. For climate-only models, mean annual precipitation and frost-free periods were the most important variables. With inclusion of LiDAR-derived attributes, depth-to-water table, terrain-intercepted annual radiation, and elevation were most often selected. This suggests that fine-scale terrain conditions affect the distribution of the studied species more than canopy conditions.

  1. Effects of gamma radiation on vegetative and reproductive phenology of herbaceous species of northern deciduous forests

    International Nuclear Information System (INIS)

    Zavitkovski, J.

    1977-01-01

    Vegetative and reproductive phenology of 38 herbaceous species of northern deciduous forests and forest roads were observed for 5 years, before (1970 and 1971), during (1972), and after (1973 and 1974) gamma irradiation. During the preirradiation years the occurrence of key vegetative and reproductive phenophases was very uniform throughout the area. This uniformity was upset by irradiation. In 1972 signs of senescence appeared earlier in most plants of the high-radiation zone (greater than or equal to 300 r/day) than in those outside that zone. In 1973 initiation of growth and completion of leaf growth of most plants was delayed by several weeks in the high-radiation zone. In both years the length of growing season was significantly shortened; this was also reflected in reduced biomass production. Vegetative development of surviving plants normalized in 1974. In 1972 flowering of forest herbs (which as a group flower early in the spring) was not affected by radiation, but that of summer-flowering logging-road herbs was delayed because the critical radiation doses were reached at that time. In 1973 all five flowering phenophases of the logging-road herbs were delayed about 3 weeks in the high-radiation zone. Normalization of reproductive phenophases became evident in 1974

  2. Direct and indirect effects of a dense understory on tree seedling recruitment in temperate forests: habitat-mediated predation versus competition

    Science.gov (United States)

    Alejandro A. Royo; Walter P. Carson

    2008-01-01

    In forests characterized by a dense woody and herbaceous understory layer, seedling recruitment is often directly suppressed via interspecific competition. Alternatively, these dense layers may indirectly lower tree recruitment by providing a haven for seed and seedling predators that prey on neighboring plant species. To simultaneously...

  3. Trophic relations of Opatrum sabulosum (Coleoptera, Tenebrionidae with leaves of cultivated and uncultivated species of herbaceous plants under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Viktor Brygadyrenko

    2015-02-01

    Full Text Available We carried out a quantitative assessment of the consumption of herbaceous plants by Opatrum sabulosum (Linnaeus, 1761 – a highly significant agricultural pest species. We researched the feeding preferences of this pest species with respect to 33 uncultivated and 22 cultivated plant species. This species of darkling beetle feeds on many uncultivated plant species, including those with hairy leaves and bitter milky sap, such as Scabiosa ucrainca (5.21 mg/specimen/24 hours, Euphorbia virgata (3.45, Solanum nigrum (3.32, Centauria scabiosa (2.47, Lamium album (2.41, Aristolochia clematitis (1.76, Chenopodium album (1.73, Arctium lappa (1.51, Asperula odorata (1.20. A high rate of leaf consumption is also characteristic for cultivated species, for example, Perilla nankinensis (5.05 mg/specimen/24 hours, Lycopersicon esculentum (3.75, Tropaeolum majus (3.29, Nicotiana tabacum (2.66, Rumex acetosa (1.96, Beta vulgaris (1.27. O. sabulosum is capable of feeding on plants which are poisonous to cattle. This species of darkling beetle consumes 95.5% of the cultivated and 48.5% of the uncultivated herbaceous plants researched.

  4. [Understory effects on overstory trees: A review.

    Science.gov (United States)

    Du, Zhong; Cai, Xiao Hu; Bao, Wei Kai; Chen, Huai; Pan, Hong Li

    2016-03-01

    Plant-plant interactions play a key role in regulating the composition and structure of communities and ecosystems. Studies of plant-plant interactions in forest ecosystems have traditionally concentrated on either tree-tree interactions or overstory species' impacts on understory plants. The possible effects of understory species on overstory trees have received less attention. We summarized the effects of understory species on soil physiological properties, soil fauna activities, leaf litter decomposition, and ecophysiology and growth of the overstory species. Then the effects of distur-bance on understory-overstory interactions were discussed. Finally, an ecophysiology-based concept model of understory effects on overstory trees was proposed. Understory removal experiments showed that the study area, overstory species age, soil fertility and understory species could significantly affect the understory-overstory interactions.

  5. Loss of native herbaceous species due to woody plant encroachment facilitates the establishment of an invasive grass.

    Science.gov (United States)

    Alofs, Karen M; Fowler, Norma L

    2013-03-01

    Although negative relationships between diversity (frequently measured as species richness) and invasibility at neighborhood or community scales have often been reported, realistic natural diversity gradients have rarely been studied at this scale. We recreated a naturally occurring gradient in species richness to test the effects of species richness on community invasibility. In central Texas savannas, as the proportion of woody plants increases (a process known as woody plant encroachment), herbaceous habitat is both lost and fragmented, and native herbaceous species richness declines. We examined the effects of these species losses on invasibility in situ by removing species that occur less frequently in herbaceous patches as woody plant encroachment advances. This realistic species removal was accompanied by a parallel and equivalent removal of biomass with no changes in species richness. Over two springs, the nonnative bunchgrass Bothriochloa ischaemum germinated significantly more often in the biomass-removal treatment than in unmanipulated control plots, suggesting an effect of native plant density independent of diversity. Additionally, significantly more germination occurred in the species-removal treatment than in the biomass-removal treatment. Changes in species richness had a stronger effect on B. ischaemum germination than changes in plant density, demonstrating that niche-related processes contributed more to biotic resistance in this system than did species-neutral competitive interactions. Similar treatment effects were found on transplant growth. Thus we show that woody plant encroachment indirectly facilitates the establishment of an invasive grass by reducing native diversity. Although we found a negative relationship between species richness and invasibility at the scale of plots with similar composition and environmental conditions, we found a positive relationship between species richness and invasibility at larger scales. This apparent

  6. Carbon dioxide and water vapour exchange from understory species in boreal forest.

    NARCIS (Netherlands)

    Heijmans, M.M.P.D.; Arp, W.J.; Chapin, F.S.

    2004-01-01

    Although recent eddy covariance measurements in boreal forests provide CO2 and energy exchange data for the whole ecosystem, very little is known about the role of the understory vegetation. We conducted chamber flux measurements in an Alaskan black spruce forest in order to compare CO2 and water

  7. Seed morphology, germination phenology, and capacity to form a seed bank in six herbaceous layer apiaceae species of the eastern deciduous forest

    Science.gov (United States)

    Tracy S. Hawkins; Jerry M. Baskin; Carol C. Baskin

    2007-01-01

    We compared seed mass, seed morphology, and long-term germination phenology of three monocarpic (MI and three polycarpic (P) Apiaceae species of the herbaceous layer of the Eastern Deciduous Forest. Seeds (mericarps) of the six species differed considerably in mass, shape, and ornamentation. Mean seed masses were ranked Cryptotaenia canadensis (M)...

  8. Effects of the arrangement works in the middle Prut meadow upon hydric metabolism in some herbaceous species at natural forest ecosystems

    Directory of Open Access Journals (Sweden)

    ACATRINEI Ligia

    2006-09-01

    Full Text Available The purpose of present paper is to evidence the major changes in hydric metabolism of some herbaceous species after arrangements works (dessecation, embankment which were made in eighties years. It were analysed the dry matter and water content; chlorophyll and carotenoid content from leaves of dominant species. Also, it has been effect a comparison of the values of the physiological

  9. Species richness, alpha and beta diversity of trees, shrubs and herbaceous plants in the woodlands of swat, pakistan

    International Nuclear Information System (INIS)

    Akhtar, N.; Bergmeier, E.

    2015-01-01

    The variation in species richness and diversity of trees, shrubs and herbs in the mountains of Miandam, Swat, North Pakistan, along an elevation gradient between 1600 m and 3400 m was explored. Field data were collected in 18 altitudinal intervals of 100 m each. Polynomial regression was used to find relations of the different growth forms with elevation. The Shannon index was used for calculating α-diversity and the Simpson index for β-diversity. Species richness and α-diversity of herbs were unrelated to elevation. Herbaceous species turnover was high, ranging between 0.46 and 0.89, with its maximum between 2700 and 3000 m. Hump-shaped relationship was observed for shrubs with maximum richness between 2000 and 2200 m; and α-diversity decreased monotonically. Turnover of shrub species was highest between 2000 and 2500 m. Tree species richness was highest at low elevations, and α-diversity was relatively low along the entire gradient. Tree species turnover was also high in the lower zone and again at 2600-2800 m. Species richness of all vascular plants was highest at 2200-2500 m, and α-diversity was highest in the lower part of the gradient. Beta diversity of all growth forms was quite high ranging between 0.53 and 0.87 along the entire gradient reflecting high species and structural turnover. (author)

  10. Limits to understory plant restoration following fuel-reduction treatments in a piñon-juniper woodland.

    Science.gov (United States)

    Redmond, Miranda D; Zelikova, Tamara J; Barger, Nichole N

    2014-11-01

    National fuel-reduction programs aim to reduce the risk of wildland fires to human communities and to restore forest and rangeland ecosystems to resemble their historical structure, function, and diversity. There are a number of factors, such as seed bank dynamics, post-treatment climate, and herbivory, which determine whether this latter goal may be achieved. Here, we examine the short-term (2 years) vegetation response to fuel-reduction treatments (mechanical mastication, broadcast burn, and pile burn) and seeding of native grasses on understory vegetation in an upland piñon-juniper woodland in southeast Utah. We also examine how wildlife herbivory affects the success of fuel-reduction treatments. Herbaceous cover increased in response to fuel-reduction treatments in all seeded treatments, with the broadcast burn and mastication having greater increases (234 and 160 %, respectively) in herbaceous cover than the pile burn (32 %). In the absence of seeding, herbaceous cover only increased in the broadcast burn (32 %). Notably, fuel-reduction treatments, but not seeding, strongly affected herbaceous plant composition. All fuel-reduction treatments increased the relative density of invasive species, especially in the broadcast burn, which shifted the plant community composition from one dominated by perennial graminoids to one dominated by annual forbs. Herbivory by wildlife reduced understory plant cover by over 40 % and altered plant community composition. If the primary management goal is to enhance understory cover while promoting native species abundance, our study suggests that mastication may be the most effective treatment strategy in these upland piñon-juniper woodlands. Seed applications and wildlife exclosures further enhanced herbaceous cover following fuel-reduction treatments.

  11. CONSUMPTION OF TREE SPECIES AND SHRUBS FOR FRUITS AND HERBACEOUS GOATS TRASHUMANCE GRAZING IN MIXTECA OAXAQUEÑA, MEXICO

    Directory of Open Access Journals (Sweden)

    F.J. Franco-Guerra

    2014-08-01

    Full Text Available The purpose of this study is to determine the weight of the bite in dry matter (DM most favorite tree and shrub species, the fruits (pods and the herbaceous stratum as a component of the diet of goats under conditions of herding transhumance in the Mixteca Baja region and the coast of Oaxaca in order to establish the capacity of ingestion. Six animals of different age and sex of a herd consisting of 963 goats were chosen randomly. The method of direct observation of grazing was used in a whole day, once established preferences, simulated manually bite and to establish the group of values from each sample was measured, and weight. The ANOVA and Bartlett's Kolmogorov-Smirnov tests were. The means comparison test was used to determine the weight of the bite in dry matter of the various species, (HSD Tukey (α, 0.05. Found a large variation prehensile act in the breadth and depth of the bite given to each depending on the type, shape and foliar surface woody species found that they graze on three anatomically different parts: on stem, in the area of the petiole and at the level of the central or main nerve of the leaf.

  12. Lianas, tree ferns and understory species: indicators of conservation status in the Brazilian Atlantic Rainforest remnants, southeastern Brazil.

    Science.gov (United States)

    Castello, A C D; Coelho, S; Cardoso-Leite, E

    2017-01-01

    Indicators are applied faster and at lower costs than conventional surveys, providing quick and efficient responses that can facilitate protected areas management. Our aim was to select indicators from vegetation to monitor protected areas. For this purpose, we analyzed understory and quantified lianas and tree ferns in protected and non-protected areas, in order to find indicator species. Our study areas are located in Vale do Ribeira, southeastern São Paulo state, Brazil. One of the areas is under two protection categories (IUCN's categories II and V), and the other is a privately owned farm. Lianas with large diameters (> 13 cm) and tree ferns with great heights (> 19 m) were considered indicators of undisturbed areas (protected areas) because their growth is directly related to forest successional stage. Indicator species within the protected area were shade tolerant species, such as Bathysa australis (A.St.-Hil.) K.Schum., whereas outside the protected area were pioneer species, such as Pera glabrata (Schott) Poepp. ex Baill. e Nectandra oppositifolia Ness. All of the suggested indicators can be used in management actions, especially in protected areas, to guarantee forest maintenance and ensure fulfillment of the conservation objectives of these areas.

  13. Lianas, tree ferns and understory species: indicators of conservation status in the Brazilian Atlantic Rainforest remnants, southeastern Brazil

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    A. C. D. Castello

    Full Text Available Abstract Indicators are applied faster and at lower costs than conventional surveys, providing quick and efficient responses that can facilitate protected areas management. Our aim was to select indicators from vegetation to monitor protected areas. For this purpose, we analyzed understory and quantified lianas and tree ferns in protected and non-protected areas, in order to find indicator species. Our study areas are located in Vale do Ribeira, southeastern São Paulo state, Brazil. One of the areas is under two protection categories (IUCN's categories II and V, and the other is a privately owned farm. Lianas with large diameters (> 13 cm and tree ferns with great heights (> 19 m were considered indicators of undisturbed areas (protected areas because their growth is directly related to forest successional stage. Indicator species within the protected area were shade tolerant species, such as Bathysa australis (A.St.-Hil. K.Schum., whereas outside the protected area were pioneer species, such as Pera glabrata (Schott Poepp. ex Baill. e Nectandra oppositifolia Ness. All of the suggested indicators can be used in management actions, especially in protected areas, to guarantee forest maintenance and ensure fulfillment of the conservation objectives of these areas.

  14. Changes in understory species occurrence of a secondary broadleaved forest after mass mortality of oak trees under deer foraging pressure

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    Hiroki Itô

    2016-12-01

    Full Text Available The epidemic of mass mortality of oak trees by Japanese oak wilt has affected secondary deciduous broadleaved forests that have been used as coppices in Japan. The dieback of oak trees formed gaps in the crown that would be expected to enhance the regeneration of shade-intolerant pioneer species. However, foraging by sika deer Cervus nippon has also affected forest vegetation, and the compound effects of both on forest regeneration should be considered when they simultaneously occur. A field study was conducted in Kyôto City, Japan to investigate how these compound effects affected the vegetation of the understory layer of these forests. The presence/absence of seedlings and saplings was observed for 200 quadrats sized 5 m ×5 m for each species in 1992, before the mass mortality and deer encroachment, and in 2014 after these effects. A hierarchical Bayesian model was constructed to explain the occurrence, survival, and colonization of each species with their responses to the gaps that were created, expanded, or affected by the mass mortality of Quercus serrata trees. The species that occurred most frequently in 1992, Eurya japonica, Quercus glauca, and Cleyera japonica, also had the highest survival probabilities. Deer-unpalatable species such as Symplocos prunifolia and Triadica sebifera had higher colonization rates in the gaps, while the deer-palatable species Aucuba japonica had the smallest survival probability. The gaps thus promoted the colonization of deer-unpalatable plant species such as Symplocos prunifolia and Triadica sebifera. In the future, such deer-unpalatable species may dominate gaps that were created, expanded, or affected by the mass mortality of oak trees.

  15. Growth characteristics and nutrient content of some herbaceous species under shade and fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Koukoura, Z.; Kyriazopoulos, A. P.; Parissi, Z. M.

    2009-07-01

    Herbage production and nutrient content are affected by light interception and soil fertility. The objective of this study was to assess the effects of artificial shade and fertilization on herbage production, growth characteristics, and nutrient content of the grass species Dactylis glomerata and Festuca ovina, and the legume species Trifolium subterraneum and Medicago lupulina. Each plant species was placed under three shading treatments of 90% (heavy shade), 50% (moderate shade) and 0% (control). Fertilization (225 kg ha{sup -}1 N, 450 kg ha{sup -}1 P, and 225 kg ha{sup -}1 K) was applied to half of the pots of every species and shading treatment. Reduced light intensity (90% shading) significantly lowered herbage production from 18% for F. ovina to 48% for D. glomerata and decreased the root:shoot (R/S) ratio of all species but the moderate reduction of light intensity (50%) did not affect R/S ratio and herbage production of the grasses and M. lupulina, while it resulted in an increase of the production of T. subterraneum by 10.5%. Reduced light intensity increased by 25% on average, the crude protein concentration of the grass species while moderate shading did not affect the crude protein concentration of T. subterraneum. Fertilization increased herbage production from 16% for F. ovina to 59% for D. glomerata and ameliorated its nutrient content. Among the tested species, D. glomerata and T. subterraneum demonstrated the highest shade tolerance and could be incorporated into silvopastoral systems of the Mediterranean region. (Author)

  16. The effect of irradiance on the carbon balance and tissue characteristics of five herbaceous species differing in shade-tolerance.

    Science.gov (United States)

    Pons, Thijs L; Poorter, Hendrik

    2014-01-01

    The carbon balance is defined here as the partitioning of daily whole-plant gross CO2 assimilation (A) in C available for growth and C required for respiration (R). A scales positively with growth irradiance and there is evidence for an irradiance dependence of R as well. Here we ask if R as a fraction of A is also irradiance dependent, whether there are systematic differences in C-balance between shade-tolerant and shade-intolerant species, and what the causes could be. Growth, gas exchange, chemical composition and leaf structure were analyzed for two shade-tolerant and three shade-intolerant herbaceous species that were hydroponically grown in a growth room at five irradiances from 20 μmol m(-2) s(-1) (1.2 mol m(-2) day(-1)) to 500 μmol m(-2) s(-1) (30 mol m(-2) day(-1)). Growth analysis showed little difference between species in unit leaf rate (dry mass increase per unit leaf area) at low irradiance, but lower rates for the shade-tolerant species at high irradiance, mainly as a result of their lower light-saturated rate of photosynthesis. This resulted in lower relative growth rates in these conditions. Daily whole-plant R scaled with A in a very tight manner, giving a remarkably constant R/A ratio of around 0.3 for all but the lowest irradiance. Although some shade-intolerant species showed tendencies toward a higher R/A and inefficiencies in terms of carbon and nitrogen investment in their leaves, no conclusive evidence was found for systematic differences in C-balance between the shade-tolerant and intolerant species at the lowest irradiance. Leaf tissue of the shade-tolerant species was characterized by high dry matter percentages, C-concentration and construction costs, which could be associated with a better defense in shade environments where leaf longevity matters. We conclude that shade-intolerant species have a competitive advantage at high irradiance due to superior potential growth rates, but that shade-tolerance is not necessarily associated

  17. The effect of irradiance on the carbon balance and tissue characteristics of five herbaceous species differing in shade-tolerance

    Directory of Open Access Journals (Sweden)

    Thijs Leendert Pons

    2014-02-01

    Full Text Available Plant photosynthesis scales positively with growth irradiance. The carbon balance, defined here as the daily whole-plant gross CO2 assimilation (A partitioned in C available for growth and C required for respiration (R, is thus irradiance dependent. Here we ask if R as a fraction of A is also irradiance dependent, whether there are systematic differences in C-balance between shade-tolerant and shade-intolerant species, and what the causes could be. Growth, gas exchange, chemical composition and leaf structure were analyzed for two shade-tolerant and three shade-intolerant herbaceous species that were hydroponically grown in a growth room at five irradiances from 20 µmol m-2 s-1 (1.2 mol m-2 day-1 to 500 µmol m-2 s-1 (30 mol m-2 day-1. Growth analysis showed little difference between species in unit leaf rate (dry mass increase per unit leaf area at low irradiance, but lower rates for the shade-tolerant species at high irradiance, mainly as a result of their lower light saturated rate of photosynthesis. This resulted in lower relative growth rates in these conditions. Daily whole-plant R scaled with A in a very tight manner, giving a remarkably constant R/A ratio of around 0.3 for all but the lowest irradiance. Although some shade-intolerant species showed tendencies towards a higher R/A and inefficiencies in terms of carbon and nitrogen investment in their leaves, no conclusive evidence was found for systematic differences in C-balance between the shade-tolerant and intolerant species at the lowest irradiance. Leaf tissue of the shade-tolerant species was characterized by high dry matter percentages, C-concentration and construction costs, which could be associated with a better defense in shade environments where leaf longevity matters. We conclude that shade-intolerant species have a competitive advantage at high irradiance due to superior potential growth rates, but that shade-tolerance is not necessarily associated with a superior C

  18. Getting the Right Traits: Reproductive and Dispersal Characteristics Predict the Invasiveness of Herbaceous Plant Species

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Lenka; Pyšek, Petr; Jarošík, Vojtěch; Pergl, Jan

    2015-01-01

    Roč. 10, č. 4 (2015), s. 1-16,no.e0123634 E-ISSN 1932-6203 R&D Projects: GA ČR GB14-36079G; GA ČR GA206/05/0323 Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : species traits * prediction * invasiveness Subject RIV: EF - Botanics Impact factor: 3.057, year: 2015

  19. Influence of microhabitats on the performance of herbaceous species in areas of mature and secondary forest in the semiarid region of Brazil

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    Juliana Ramos de Andrade

    2015-06-01

    Full Text Available The conditions for plant establishment in mature forest are different from those found in disturbed areas. In dry environments, the herbaceous cover is the most important in the recolonization of deforested areas. It can, therefore, act as an ideal biological group for assessing how changes in habitat heterogeneity affect the resilience of dry forests. The aim of this research was to evaluate whether natural regeneration of the herbaceous stratum differed between areas of mature and secondary forest of Caatinga and to describe this process. The study took place in the Brazilian semiarid region during the rainy season 2011 (January to August, where fifty 1m² plots were set up, 25 allocated to the microhabitat established as “between canopies” and 25 to the microhabitat “under the canopy”. The herbaceous species selected for the study were Delilia biflora (Asteraceae, Gomphrena vaga (Amaranthaceae and Pseudabutilon spicatum (Malvaceae, abundant species occurring in both areas. All individuals from the selected populations were counted, marked with sequential numbers, and the height of the stem was measured. Differences between areas, and in size and survival between microhabitats, were found only for the first two species. Fruit production was higher in the mature forest for the three species. The study concluded that: 1. The effect of the microhabitats “between canopies” and “under the canopy” in mature and secondary forest areas depends on the species considered; 2. Populations sensitive to light intensity differ in number of individuals, height and fruit production; and 3. The resilience of anthropogenic areas in semiarid environments can be characterized by the presence of spatial heterogeneity with regard to the emergence and survival of herbaceous seedlings, suggesting that the regeneration of disturbed areas may occur in patches. Rev. Biol. Trop. 63 (2: 357-368. Epub 2015 June 01.

  20. Contrasting xylem vessel constraints on hydraulic conductivity between native and non-native woody understory species

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    Maria S Smith

    2013-11-01

    Full Text Available We examined the hydraulic properties of 82 native and non-native woody species common to forests of Eastern North America, including several congeneric groups, representing a range of anatomical wood types. We observed smaller conduit diameters with greater frequency in non-native species, corresponding to lower calculated potential vulnerability to cavitation index. Non-native species exhibited higher vessel-grouping in metaxylem compared with native species, however, solitary vessels were more prevalent in secondary xylem. Higher frequency of solitary vessels in secondary xylem was related to a lower potential vulnerability index. We found no relationship between anatomical characteristics of xylem, origin of species and hydraulic conductivity, indicating that non-native species did not exhibit advantageous hydraulic efficiency over native species. Our results confer anatomical advantages for non-native species under the potential for cavitation due to freezing, perhaps permitting extended growing seasons.

  1. Relative Sensitivity of Photosynthesis and Respiration to Freeze-Thaw Stress in Herbaceous Species 1

    Science.gov (United States)

    Steffen, Kenneth L.; Arora, Rajeev; Palta, Jiwan P.

    1989-01-01

    The relative effect of a freeze-thaw cycle on photosynthesis, respiration, and ion leakage of potato leaf tissue was examined in two potato species, Solanum acaule Bitt. and Solanum commersonii Dun. Photosynthesis was found to be much more sensitive to freezing stress than was respiration, and demonstrated more than a 60% inhibition before any impairment of respiratory function was observed. Photosynthesis showed a slight to moderate inhibition when only 5 to 10% of the total electrolytes had leaked from the tissue (reversible injury). This was in contrast to respiration which showed no impairment until temperatures at which about 50% ion leakage (irreversible injury) had occurred. The influence of freeze-thaw protocol was further examined in S. acaule and S. commersonii, in order to explore discrepancies in the literature as to the relative sensitivities of photosynthesis and respiration. As bath cooling rates increased from 1°C/hour to about 3 or 6°C/hour, there was a dramatic increase in the level of damage to all measured cellular functions. The initiation of ice formation in deeply supercooled tissue caused even greater damage. As the cooling rates used in stress treatments increased, the differential sensitivity between photosynthesis and respiration nearly disappeared. Examination of agriculturally relevant, climatological data from an 11 year period confirmed that air cooling rates in the freezing range do not exceed 2°C/hour. It was demonstrated, in the studies presented here, that simply increasing the actual cooling rate from 1.0 to 2.9°C/hour, in frozen tissue from paired leaflet halves, meant the difference between cell survival and cell death. Images Figure 4 Figure 5 PMID:16666712

  2. Variation in herbaceous vegetation and soil moisture under treated and untreated oneseed juniper trees

    Science.gov (United States)

    Hector Ramirez; Alexander Fernald; Andres Cibils; Michelle Morris; Shad Cox; Michael Rubio

    2008-01-01

    Clearing oneseed juniper (Juniperus monosperma) may make more water available for aquifer recharge or herbaceous vegetation growth, but the effects of tree treatment on soil moisture dynamics are not fully understood. This study investigated juniper treatment effects on understory herbaceous vegetation concurrently with soil moisture dynamics using vegetation sampling...

  3. The effect of herbaceous species removal, fire and cheatgrass (Bromus tectorum) on soil water availability in sagebrush steppe

    Science.gov (United States)

    Alison Whittaker; Bruce Roundy; Jeanne Chambers; Susan Meyer; Robert Blank; Stanley Kitchen; John Korfmacher

    2008-01-01

    Over the past several decades, cheatgrass (Bromus tectorum) has been continually expanding in the sagebrush steppe ecosystem. There has been very little research that examines why cheatgrass is able to invade these communities. To determine the effects of herbaceous vegetation removal and fire on available water for cheatgrass invasion, as well as...

  4. Prescribed burning for understory restoration

    Science.gov (United States)

    Kenneth W. Outcalt

    2006-01-01

    Because the longleaf ecosystem evolved with and is adapted to frequent fire, every 2 to 8 years, prescribed burning is often useful for restoring understory communities to a diverse ground layer of grasses, herbs, and small shrubs. This restoration provides habitat for a number of plant and animal species that are restricted to or found mostly in longleaf pine...

  5. Partitioning understory evapotranspiration in semi-arid ecosystems in Namibia using the isotopic composition of water vapour

    Science.gov (United States)

    de Blécourt, Marleen; Gaj, Marcel; Holtorf, Kim-Kirsten; Gröngröft, Alexander; Brokate, Ralph; Himmelsbach, Thomas; Eschenbach, Annette

    2016-04-01

    In dry environments with a sparse vegetation cover, understory evapotranspiration is a major component of the ecosystem water balance. Consequently, knowledge on the size of evapotranspiration fluxes and the driving factors is important for our understanding of the hydrological cycle. Understory evapotranspiration is made up of soil evaporation and plant transpiration. Soil evaporation can be measured directly from patches free of vegetation. However, when understory vegetation is present distinguishing between soil evaporation and plant transpiration is challenging. In this study, we aim to partition understory evapotranspiration based on an approach that combines the measurements of water-vapour fluxes using the closed chamber method with measurements of the isotopic composition of water vapour. The measurements were done in the framework of SASSCAL (Southern African Science Service Centre for Climate Change and Adaptive Land Management). The study sites were located in three different semi-arid ecosystems in Namibia: thornbush savanna, Baikiaea woodland and shrubland. At each site measurements were done under tree canopies as well as at unshaded areas between the canopies. We measured evaporation from the bare soil and evapotranspiration from patches covered with herbaceous species and shrubs using a transparent chamber connected with an infrared gas analyser (LI-8100A, LICOR Inc.). The stable isotope composition of water vapour inside the chamber and depth profiles of soil water stable isotopes were determined in-situ using a tuneable off-axis integrated cavity output spectroscope (OA-ICOS, Los Gatos Research, DLT 100). Xylem samples were extracted using the cryogenic vacuum extraction method and the isotopic composition of the extracted water was measured subsequently with a cavity-ring-down spectrometer (CRDS L2120-i, Picarro Inc.). We will present the quantified fluxes of understory evapotranspiration measured in the three different ecosystems, show the

  6. Comparing herbaceous plant communities in active and passive riparian restoration.

    Directory of Open Access Journals (Sweden)

    Elise S Gornish

    Full Text Available Understanding the efficacy of passive (reduction or cessation of environmental stress and active (typically involving planting or seeding restoration strategies is important for the design of successful revegetation of degraded riparian habitat, but studies explicitly comparing restoration outcomes are uncommon. We sampled the understory herbaceous plant community of 103 riparian sites varying in age since restoration (0 to 39 years and revegetation technique (active, passive, or none to compare the utility of different approaches on restoration success across sites. We found that landform type, percent shade, and summer flow helped explain differences in the understory functional community across all sites. In passively restored sites, grass and forb cover and richness were inversely related to site age, but in actively restored sites forb cover and richness were inversely related to site age. Native cover and richness were lower with passive restoration compared to active restoration. Invasive species cover and richness were not significantly different across sites. Although some of our results suggest that active restoration would best enhance native species in degraded riparian areas, this work also highlights some of the context-dependency that has been found to mediate restoration outcomes. For example, since the effects of passive restoration can be quite rapid, this approach might be more useful than active restoration in situations where rapid dominance of pioneer species is required to arrest major soil loss through erosion. As a result, we caution against labeling one restoration technique as better than another. Managers should identify ideal restoration outcomes in the context of historic and current site characteristics (as well as a range of acceptable alternative states and choose restoration approaches that best facilitate the achievement of revegetation goals.

  7. Involvement of allelopathy in inhibition of understory growth in red pine forests.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Kimura, Fukiko; Ohno, Osamu; Suenaga, Kiyotake

    2017-11-01

    Japanese red pine (Pinus densiflora Sieb. et Zucc.) forests are characterized by sparse understory vegetation although sunlight intensity on the forest floor is sufficient for undergrowth. The possible involvement of pine allelopathy in the establishment of the sparse understory vegetation was investigated. The soil of the red pine forest floor had growth inhibitory activity on six test plant species including Lolium multiflorum, which was observed at the edge of the forest but not in the forest. Two growth inhibitory substances were isolated from the soil and characterized to be 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid. Those compounds are probably formed by degradation process of resin acids. Resin acids are produced by pine and delivered into the soil under the pine trees through balsam and defoliation. Threshold concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid for the growth inhibition of L. multiflorum were 30 and 10μM, respectively. The concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid in the soil were 312 and 397μM, respectively, which are sufficient concentrations to cause the growth inhibition because of the threshold. These results suggest that those compounds are able to work as allelopathic agents and may prevent from the invasion of herbaceous plants into the forests by inhibiting their growth. Therefore, allelopathy of red pine may be involved in the formation of the sparse understory vegetation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. Long-term deer exclusion has complex effects on a suburban forest understory

    Science.gov (United States)

    Faison, Edward K.; Foster, David R.; DeStefano, Stephen

    2016-01-01

    Herbivory by deer is one of the leading biotic disturbances on forest understories (i.e., herbs, small shrubs, and small tree seedlings). A large body of research has reported declines in height, abundance, and reproductive capacity of forbs and woody plants coupled with increases in abundance of graminoids, ferns, and exotic species due to deer herbivory. Less clear is the extent to which (and the direction in which) deer alter herbaceous layer diversity, where much of the plant diversity in a forest occurs. We examined the effect of 15 y of deer exclusion on the understory of a suburban hardwood forest in Connecticut exposed to decades of intensive herbivory by white-tailed deer (Odocoileus virginianus). We compared species richness (at subplot and plot scale), individual species and life form group abundance (% cover), and community composition between grazed and exclosure plots, as well as between mesic and wet soil blocks. Forb cover was more than twice as abundant in exclosure as in grazed plots, whereas sedge (Carex spp.) cover was 28 times more abundant, and exotic species cover generally higher in grazed than in exclosure plots. Native and exotic species richness were both higher in grazed than exclosure plots at the subplot scale, and native herbaceous richness was higher in grazed plots at both spatial scales. In contrast, native shrub richness increased with deer exclusion at the plot scale. Our results suggest that deer exclusion had contrasting effects on species richness, depending on plant life form, but that overall richness of both exotic and native plants declined with deer exclusion. In addition, site heterogeneity remained an important driver of vegetation dynamics even in the midst of high deer densities.

  9. Conversion of Levulinic Acid from Various Herbaceous Biomass Species Using Hydrochloric Acid and Effects of Particle Size and Delignification

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    Indra Neel Pulidindi

    2018-03-01

    Full Text Available Acid catalyzed hydrothermal conversion of levulinic acid (LA from various herbaceous materials including rice straw (RS, corn stover (CS, sweet sorghum bagasse (SSB, and Miscanthus (MS was evaluated. With 1 M HCl, 150 °C, 5 h, 20 g/L solid loading, the yields of LA from untreated RS, CS, SSB and MS based on the glucan content were 60.2, 75.1, 78.5 and 61.7 wt %, respectively. It was also found that the particle size had no significant effect on LA conversion yield with >3 h reaction time. With delignification using simulated green liquor (Na2CO3-Na2S, 20 wt % total titratable alkali (TTA, 40 wt % sulfidity at 200 °C for 15 min, lignin removal was in the range of 64.8–91.2 wt %. Removal of both lignin and xylan during delignification increased the glucan contents from 33.0–44.3 of untreated biomass to 61.7–68.4 wt % of treated biomass. Delignified biomass resulted in much lower conversion yield (50.4–56.0 wt % compared to 60.2–78.5 wt % of untreated biomass. Nonetheless, the concentration of LA in the product was enhanced by a factor of ~1.5 with delignification.

  10. Prescribed Burning and Clear-Cutting Effects on Understory Vegetation in a Pinus canariensis Stand (Gran Canaria

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    José Ramón Arévalo

    2014-01-01

    Full Text Available Prescribed fires are a powerful tool for reducing fire hazards by decreasing amounts of fuel. The main objective is to analyze the effects of prescribed burning on the understory vegetation composition as well as on the soil characteristics of a reforested stand of Pinus canariensis. The study attempts to identify the effects of the preburning treatment of cutting understory vegetation on the floristic parameters of the vegetation community. This study was carried out for two years following a prescribed fire in a Canarian pine stand. Cutting and burning treatment affected species composition and increased diversity. Burnt and cut plots were characterized by a diverse array of herbaceous species and by a lower abundance of Teline microphylla (endemic legume, although burning apparently induced its germination. Cut treatment was more consistently differentiated from the control plots than burnt treatment. Soil K decreased after both treatments, pH slightly decreased after cutting, while P and Ca increased after fire. From an ecological point of view, prescribed burning is a better management practice than cutting the woody species of the understory. However, long-term studies would be necessary to evaluate the effects of fire intensity, season and frequency in which the prescribed burning is applied.

  11. Prescribed burning and clear-cutting effects on understory vegetation in a Pinus canariensis stand (Gran Canaria).

    Science.gov (United States)

    Arévalo, José Ramón; Fernández-Lugo, Silvia; García-Domínguez, Celia; Naranjo-Cigala, Agustín; Grillo, Federico; Calvo, Leonor

    2014-01-01

    Prescribed fires are a powerful tool for reducing fire hazards by decreasing amounts of fuel. The main objective is to analyze the effects of prescribed burning on the understory vegetation composition as well as on the soil characteristics of a reforested stand of Pinus canariensis. The study attempts to identify the effects of the preburning treatment of cutting understory vegetation on the floristic parameters of the vegetation community. This study was carried out for two years following a prescribed fire in a Canarian pine stand. Cutting and burning treatment affected species composition and increased diversity. Burnt and cut plots were characterized by a diverse array of herbaceous species and by a lower abundance of Teline microphylla (endemic legume), although burning apparently induced its germination. Cut treatment was more consistently differentiated from the control plots than burnt treatment. Soil K decreased after both treatments, pH slightly decreased after cutting, while P and Ca increased after fire. From an ecological point of view, prescribed burning is a better management practice than cutting the woody species of the understory. However, long-term studies would be necessary to evaluate the effects of fire intensity, season and frequency in which the prescribed burning is applied.

  12. Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources

    Directory of Open Access Journals (Sweden)

    Izaias M Fernandes

    Full Text Available The influence of habitat, biomass of herbaceous vegetation, depth and distance from permanent water bodies on the structure of fish assemblages of a seasonal floodplain was evaluated using data collected along 22 transects in an area of 25 km² in the floodplain of Cuiabá River, Pantanal, Brazil. Each transect was sampled for fish using throw traps and gillnets during the flood period of 2006. Multivariate multiple regression analysis and multivariate analysis of covariance indicated that depth was the only variable that affected the structure of the fish assemblage, both for quantitative data (abundance and qualitative data (presence-absence. Species such as Neofundulus parvipinnis and Laetacara dorsigera were more abundant in shallower sites (below 25 cm, while Serrasalmus maculatus and Metynnis mola were found mostly in the deepest areas (over 55 cm. However, species such as Hoplias malabaricus and Hoplerythrinus unitaeniatus occurred at all sampled depths. Although the distribution of most species was restricted to a few sites, there was a positive relationship between species richness and depth of the water body. Surprisingly, the replacement of native vegetation by exotic pasture did not affect the fish assemblage in the area, at the probability level considered.

  13. Understory response to varying fire frequencies after 20 years of prescribed burning in an upland oak forest

    Science.gov (United States)

    Burton, J.A.; Hallgren, S.W.; Fuhlendorf, S.D.; Leslie, David M.

    2011-01-01

    Ecosystems in the eastern United States that were shaped by fire over thousands of years of anthropogenic burning recently have been subjected to fire suppression resulting in significant changes in vegetation composition and structure and encroachment by invasive species. Renewed interest in use of fire to manage such ecosystems will require knowledge of effects of fire regime on vegetation. We studied the effects of one aspect of the fire regime, fire frequency, on biomass, cover and diversity of understory vegetation in upland oak forests prescribe-burned for 20 years at different frequencies ranging from zero to five fires per decade. Overstory canopy closure ranged from 88 to 96% and was not affected by fire frequency indicating high tolerance of large trees for even the most frequent burning. Understory species richness and cover was dominated by woody reproduction followed in descending order by forbs, C3 graminoids, C4 grasses, and legumes. Woody plant understory cover did not change with fire frequency and increased 30% from one to three years after a burn. Both forbs and C3 graminoids showed a linear increase in species richness and cover as fire frequency increased. In contrast, C4 grasses and legumes did not show a response to fire frequency. The reduction of litter by fire may have encouraged regeneration of herbaceous plants and helped explain the positive response of forbs and C3 graminoids to increasing fire frequency. Our results showed that herbaceous biomass, cover, and diversity can be managed with long-term prescribed fire under the closed canopy of upland oak forests. ?? 2011 Springer Science+Business Media B.V.

  14. Effects of Ontogeny on δ13C of Plant- and Soil-Respired CO2 and on Respiratory Carbon Fractionation in C3 Herbaceous Species.

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    Yann Salmon

    Full Text Available Knowledge gaps regarding potential ontogeny and plant species identity effects on carbon isotope fractionation might lead to misinterpretations of carbon isotope composition (δ13C of respired CO2, a widely-used integrator of environmental conditions. In monospecific mesocosms grown under controlled conditions, the δ13C of C pools and fluxes and leaf ecophysiological parameters of seven herbaceous species belonging to three functional groups (crops, forage grasses and legumes were investigated at three ontogenetic stages of their vegetative cycle (young foliage, maximum growth rate, early senescence. Ontogeny-related changes in δ13C of leaf- and soil-respired CO2 and 13C/12C fractionation in respiration (ΔR were species-dependent and up to 7‰, a magnitude similar to that commonly measured in response to environmental factors. At plant and soil levels, changes in δ13C of respired CO2 and ΔR with ontogeny were related to changes in plant physiological status, likely through ontogeny-driven changes in the C sink to source strength ratio in the aboveground plant compartment. Our data further showed that lower ΔR values (i.e. respired CO2 relatively less depleted in 13C were observed with decreasing net assimilation. Our findings highlight the importance of accounting for ontogenetic stage and plant community composition in ecological studies using stable carbon isotopes.

  15. Effects of Ontogeny on δ13C of Plant- and Soil-Respired CO2 and on Respiratory Carbon Fractionation in C3 Herbaceous Species.

    Science.gov (United States)

    Salmon, Yann; Buchmann, Nina; Barnard, Romain L

    2016-01-01

    Knowledge gaps regarding potential ontogeny and plant species identity effects on carbon isotope fractionation might lead to misinterpretations of carbon isotope composition (δ13C) of respired CO2, a widely-used integrator of environmental conditions. In monospecific mesocosms grown under controlled conditions, the δ13C of C pools and fluxes and leaf ecophysiological parameters of seven herbaceous species belonging to three functional groups (crops, forage grasses and legumes) were investigated at three ontogenetic stages of their vegetative cycle (young foliage, maximum growth rate, early senescence). Ontogeny-related changes in δ13C of leaf- and soil-respired CO2 and 13C/12C fractionation in respiration (ΔR) were species-dependent and up to 7‰, a magnitude similar to that commonly measured in response to environmental factors. At plant and soil levels, changes in δ13C of respired CO2 and ΔR with ontogeny were related to changes in plant physiological status, likely through ontogeny-driven changes in the C sink to source strength ratio in the aboveground plant compartment. Our data further showed that lower ΔR values (i.e. respired CO2 relatively less depleted in 13C) were observed with decreasing net assimilation. Our findings highlight the importance of accounting for ontogenetic stage and plant community composition in ecological studies using stable carbon isotopes.

  16. Influence of Afforestation on the Species Diversity of the Soil Seed Bank and Understory Vegetation in the Hill-Gullied Loess Plateau, China.

    Science.gov (United States)

    Wang, Ning; Jiao, Juying; Jia, Yanfeng; Wang, Dongli

    2017-10-24

    The Chinese Loess Plateau region has long been suffering from serious soil erosion. Thus, large-scale afforestation has continued during the past decades in order to control soil erosion. Afforestation can dramatically alter nutrient cycles, affect soil-carbon storage, and change hydrology. However, it is unknown how afforestation influences species diversity of the soil seed bank and understory vegetation compared with spontaneous restoration of abandoned land. Forest land with trees planted 30 years ago, abandoned slope land restored spontaneously for 30 years, and the corresponding slopes with remnant natural vegetation were selected as sampling sites. The species richness both in the soil seed bank and vegetation was significantly higher on the afforested slope compared to the spontaneously restored abandoned land. The species similarity between the afforested slope and the remnant slope land was high both in the soil seed bank and standing vegetation compared to the abandoned land. The soil seed bank density varied from 1778 ± 187 to 3896 ± 221 seeds/m², and more than half of it was constituted by annual and biennial species, with no significant difference among sampling habitats. However, the afforested slope had higher seed density of grass and shrub/subshrubs compared to the abandoned slope. The present study indicates that in the study region, characterized by serious soil erosion, afforestation can better facilitate vegetation succession compared to spontaneously restoration of abandoned slope land.

  17. Influence of Afforestation on the Species Diversity of the Soil Seed Bank and Understory Vegetation in the Hill-Gullied Loess Plateau, China

    Science.gov (United States)

    Wang, Ning; Jiao, Juying; Jia, Yanfeng; Wang, Dongli

    2017-01-01

    The Chinese Loess Plateau region has long been suffering from serious soil erosion. Thus, large-scale afforestation has continued during the past decades in order to control soil erosion. Afforestation can dramatically alter nutrient cycles, affect soil-carbon storage, and change hydrology. However, it is unknown how afforestation influences species diversity of the soil seed bank and understory vegetation compared with spontaneous restoration of abandoned land. Forest land with trees planted 30 years ago, abandoned slope land restored spontaneously for 30 years, and the corresponding slopes with remnant natural vegetation were selected as sampling sites. The species richness both in the soil seed bank and vegetation was significantly higher on the afforested slope compared to the spontaneously restored abandoned land. The species similarity between the afforested slope and the remnant slope land was high both in the soil seed bank and standing vegetation compared to the abandoned land. The soil seed bank density varied from 1778 ± 187 to 3896 ± 221 seeds/m2, and more than half of it was constituted by annual and biennial species, with no significant difference among sampling habitats. However, the afforested slope had higher seed density of grass and shrub/subshrubs compared to the abandoned slope. The present study indicates that in the study region, characterized by serious soil erosion, afforestation can better facilitate vegetation succession compared to spontaneously restoration of abandoned slope land. PMID:29064405

  18. Influence of tree cover on herbaceous layer development and carbon and water fluxes in a Portuguese cork-oak woodland

    Science.gov (United States)

    Dubbert, Maren; Mosena, Alexander; Piayda, Arndt; Cuntz, Matthias; Correia, Alexandra Cristina; Pereira, Joao Santos; Werner, Christiane

    2014-08-01

    Facilitation and competition between different vegetation layers may have a large impact on small-scale vegetation development. We propose that this should not only influence overall herbaceous layer yield but also species distribution and understory longevity, and hence the ecosystems carbon uptake capacity especially during spring. We analyzed the effects of trees on microclimate and soil properties (water and nitrate content) as well as the development of an herbaceous community layer regarding species composition, aboveground biomass and net water and carbon fluxes in a cork-oak woodland in Portugal, between April and November 2011. The presence of trees caused a significant reduction in photosynthetic active radiation of 35 mol m-2 d-1 and in soil temperature of 5 °C from April to October. At the same time differences in species composition between experimental plots located in open areas and directly below trees could be observed: species composition and abundance of functional groups became increasingly different between locations from mid April onwards. During late spring drought adapted native forbs had significantly higher cover and biomass in the open area while cover and biomass of grasses and nitrogen fixing forbs was highest under the trees. Further, evapotranspiration and net carbon exchange decreased significantly stronger under the tree crowns compared to the open during late spring and the die back of herbaceous plants occurred earlier and faster under trees. This was most likely caused by interspecific competition for water between trees and herbaceous plants, despite the more favorable microclimate conditions under the trees during the onset of summer drought.

  19. Early growth interactions between a mangrove and an herbaceous salt marsh species are not affected by elevated CO2 or drought

    Science.gov (United States)

    Howard, Rebecca J.; Stagg, Camille L.; Utomo, Herry S.

    2018-01-01

    Increasing atmospheric carbon dioxide (CO2) concentrations are likely to influence future distributions of plants and plant community structure in many regions of the world through effects on photosynthetic rates. In recent decades the encroachment of woody mangrove species into herbaceous marshes has been documented along the U.S. northern Gulf of Mexico coast. These species shifts have been attributed primarily to rising sea levels and warming winter temperatures, but the role of elevated CO2 and water availability may become more prominent drivers of species interactions under future climate conditions. Drought has been implicated as a major factor contributing to salt marsh vegetation dieback in this region. In this greenhouse study we examined the effects of CO2 concentration (∼380 ppm, ∼700 ppm) and water regime (drought, saturated, flooded) on early growth of Avicennia germinans, a C3 mangrove species, and Spartina alterniflora, a C4 grass. Plants were grown in monocultures and in a mixed-species assemblage. We found that neither species responded to elevated CO2 over the 10-month duration of the experiment, and there were few interactions between experimental factors. Two effects of water regime were documented: lower A. germinanspneumatophore biomass under drought conditions, and lower belowground biomass under flooded conditions regardless of planting assemblage. Evidence of interspecific interactions was noted. Competition for aboveground resources (e.g., light) was indicated by lower S. alterniflora stem biomass in mixed-species assemblage compared to biomass in S. alterniflora monocultures. Pneumatophore biomass of A. germinans was reduced when grown in monoculture compared to the mixed-species assemblage, indicating competition for belowground resources. These interactions provide insight into how these species may respond following major disturbance events that lead to vegetation dieback. Site variation in propagule availability

  20. INTERACTIONS BETWEEN THE HERBACEOUS AND SHRUBBY-ARBOREAL COMPONENTS IN A SEMIARID REGION IN THE NORTHEAST OF BRAZIL: COMPETITION OR FACILITATION?

    Directory of Open Access Journals (Sweden)

    KLEBER ANDRADE DA SILVA

    2015-01-01

    Full Text Available Under conditions of high stress, interactions between species can be positive. Islands of perennial vegetation can improve the conditions of the understory and facilitate the establishment of herbaceous plants. The hypothesis of this study is that islands of perennial vegetation in an area of caatinga harbor, a greater richness, diversity and density of herbaceous plants, and that individuals reach a greater height and diameter than in open spaces. The study was conducted in Petrolândia, Pernambuco, Brazil. Twenty-seven plots were installed in the center of the islands, 38 at the edge of the islands (in a total of 38 islands and 35 in the open spaces. A total of 51 species were recorded in the center and 55 on the edge of the islands and 48 in the open spaces. The mean richness of the open spaces was lower than on the islands. The diversity was greater in the center of the island and became less on the edge of the island and in the open spaces. The mean density was lower in the open spaces than on the islands. The mean density at the edge of the islands was greater than in the center of the islands. There was no difference in mean diameter of herbaceous plants. The mean height of the individuals was higher in the center of the islands. The herbaceous community growing on the islands exhibited higher richness, diversity, density and height than in open spaces. Thus, islands of perennial vegetation facilitate the establishment of herbaceous species.

  1. Understory Bird Communities in Amazonian Rainforest Fragments: Species Turnover through 25 Years Post-Isolation in Recovering Landscapes

    Science.gov (United States)

    Stouffer, Philip C.; Johnson, Erik I.; Bierregaard, Richard O.; Lovejoy, Thomas E.

    2011-01-01

    Inferences about species loss following habitat conversion are typically drawn from short-term surveys, which cannot reconstruct long-term temporal dynamics of extinction and colonization. A long-term view can be critical, however, to determine the stability of communities within fragments. Likewise, landscape dynamics must be considered, as second growth structure and overall forest cover contribute to processes in fragments. Here we examine bird communities in 11 Amazonian rainforest fragments of 1–100 ha, beginning before the fragments were isolated in the 1980s, and continuing through 2007. Using a method that accounts for imperfect detection, we estimated extinction and colonization based on standardized mist-net surveys within discreet time intervals (1–2 preisolation samples and 4–5 post-isolation samples). Between preisolation and 2007, all fragments lost species in an area-dependent fashion, with loss of as few as <10% of preisolation species from 100-ha fragments, but up to 70% in 1-ha fragments. Analysis of individual time intervals revealed that the 2007 result was not due to gradual species loss beginning at isolation; both extinction and colonization occurred in every time interval. In the last two samples, 2000 and 2007, extinction and colonization were approximately balanced. Further, 97 of 101 species netted before isolation were detected in at least one fragment in 2007. Although a small subset of species is extremely vulnerable to fragmentation, and predictably goes extinct in fragments, developing second growth in the matrix around fragments encourages recolonization in our landscapes. Species richness in these fragments now reflects local turnover, not long-term attrition of species. We expect that similar processes could be operating in other fragmented systems that show unexpectedly low extinction. PMID:21731616

  2. Understory bird communities in Amazonian rainforest fragments: species turnover through 25 years post-isolation in recovering landscapes.

    Directory of Open Access Journals (Sweden)

    Philip C Stouffer

    Full Text Available Inferences about species loss following habitat conversion are typically drawn from short-term surveys, which cannot reconstruct long-term temporal dynamics of extinction and colonization. A long-term view can be critical, however, to determine the stability of communities within fragments. Likewise, landscape dynamics must be considered, as second growth structure and overall forest cover contribute to processes in fragments. Here we examine bird communities in 11 Amazonian rainforest fragments of 1-100 ha, beginning before the fragments were isolated in the 1980s, and continuing through 2007. Using a method that accounts for imperfect detection, we estimated extinction and colonization based on standardized mist-net surveys within discreet time intervals (1-2 preisolation samples and 4-5 post-isolation samples. Between preisolation and 2007, all fragments lost species in an area-dependent fashion, with loss of as few as <10% of preisolation species from 100-ha fragments, but up to 70% in 1-ha fragments. Analysis of individual time intervals revealed that the 2007 result was not due to gradual species loss beginning at isolation; both extinction and colonization occurred in every time interval. In the last two samples, 2000 and 2007, extinction and colonization were approximately balanced. Further, 97 of 101 species netted before isolation were detected in at least one fragment in 2007. Although a small subset of species is extremely vulnerable to fragmentation, and predictably goes extinct in fragments, developing second growth in the matrix around fragments encourages recolonization in our landscapes. Species richness in these fragments now reflects local turnover, not long-term attrition of species. We expect that similar processes could be operating in other fragmented systems that show unexpectedly low extinction.

  3. Effect of removal of hesperis matronalis (Dame's rocket) on species cover of forest understory vegetation in NW indiana

    Science.gov (United States)

    Pavlovic, N.B.; Leicht-Young, S. A.; Frohnapple, K.J.; Grundel, R.

    2009-01-01

    Exotic invasive plant species differ in their effects on indigenous vegetation as evidenced by research evaluating community response to their removal. We used a removal approach to quantify the response of a mesic woodland to the removal versus retention of an invasive plant, Hesperis matronalis (dame's rocket) from paired treatment plots over 3 y. Cover of H. matronalis did not differ between control and treatment plots prior to removal, declined in the removal plots and remained significantly lower in cover compared to the control plots. Removal did not significantly affect species richness and species diversity (evenness, Shannon and Simpson) at the plot scale, but did result in increased species richness overall in the removal plots in the last sampling year when compared to control plots. Non-metric multidimensional scaling ordination analysis indicated a significant compositional change in the spring plant composition of plots over the 3 y, reflecting an increase in exotic woody species. Exotic woody plants, especially Rosa multiflora and Euonymus alatus, increased in cover in response to H. matronalis removal. In the 3 y, neither native nor exotic forbs, nor native woody plants responded to the removal of H. matronalis in a statistically significant manner. The increasing cover of woody invasive plants in response to the removal of H. matronalis has important management implications for restoration of degraded communities.

  4. [Distribution patterns of canopy and understory tree species at local scale in a Tierra Firme forest, the Colombian Amazonia].

    Science.gov (United States)

    Barreto-Silva, Juan Sebastian; López, Dairon Cárdenas; Montoya, Alvaro Javier Duque

    2014-03-01

    The effect of environmental variation on the structure of tree communities in tropical forests is still under debate. There is evidence that in landscapes like Tierra Firme forest, where the environmental gradient decreases at a local level, the effect of soil on the distribution patterns of plant species is minimal, happens to be random or is due to biological processes. In contrast, in studies with different kinds of plants from tropical forests, a greater effect on floristic composition of varying soil and topography has been reported. To assess this, the current study was carried out in a permanent plot of ten hectares in the Amacayacu National Park, Colombian Amazonia. To run the analysis, floristic and environmental variations were obtained according to tree species abundance categories and growth forms. In order to quantify the role played by both environmental filtering and dispersal limitation, the variation of the spatial configuration was included. We used Detrended Correspondence Analysis and Canonical Correspondence Analysis, followed by a variation partitioning, to analyze the species distribution patterns. The spatial template was evaluated using the Principal Coordinates of Neighbor Matrix method. We recorded 14 074 individuals from 1 053 species and 80 families. The most abundant families were Myristicaceae, Moraceae, Meliaceae, Arecaceae and Lecythidaceae, coinciding with other studies from Northwest Amazonia. Beta diversity was relatively low within the plot. Soils were very poor, had high aluminum concentration and were predominantly clayey. The floristic differences explained along the ten hectares plot were mainly associated to biological processes, such as dispersal limitation. The largest proportion of community variation in our dataset was unexplained by either environmental or spatial data. In conclusion, these results support random processes as the major drivers of the spatial variation of tree species at a local scale on Tierra Firme

  5. Diversity patterns of ground beetles and understory vegetation in mature, secondary, and plantation forest regions of temperate northern China.

    Science.gov (United States)

    Zou, Yi; Sang, Weiguo; Wang, Shunzhong; Warren-Thomas, Eleanor; Liu, Yunhui; Yu, Zhenrong; Wang, Changliu; Axmacher, Jan Christoph

    2015-02-01

    Plantation and secondary forests form increasingly important components of the global forest cover, but our current knowledge about their potential contribution to biodiversity conservation is limited. We surveyed understory plant and carabid species assemblages at three distinct regions in temperate northeastern China, dominated by mature forest (Changbaishan Nature Reserve, sampled in 2011 and 2012), secondary forest (Dongling Mountain, sampled in 2011 and 2012), and forest plantation habitats (Bashang Plateau, sampled in 2006 and 2007), respectively. The α-diversity of both taxonomic groups was highest in plantation forests of the Bashang Plateau. Beetle α-diversity was lowest, but plant and beetle species turnover peaked in the secondary forests of Dongling Mountain, while habitats in the Changbaishan Nature Reserve showed the lowest turnover rates for both taxa. Changbaishan Nature Reserve harbored the highest proportion of forest specialists. Our results suggest that in temperate regions of northern China, the protected larch plantation forest established over extensive areas might play a considerable role in maintaining a high biodiversity in relation to understory herbaceous plant species and carabid assemblages, which can be seen as indicators of forest disturbance. The high proportion of phytophagous carabids and the rarity of forest specialists reflect the relatively homogenous, immature status of the forest ecosystems on the Bashang Plateau. China's last remaining large old-growth forests like the ones on Changbaishan represent stable, mature ecosystems which require particular conservation attention.

  6. Understory response to disturbance: an investigation of prescribed burning and understory thinning treatments

    Science.gov (United States)

    Benjamin J. Dolan; George R. Parker

    2003-01-01

    Lack of disturbance in the Central Hardwood Region has caused a decrease in abundance of shade-intolerant species, such as oaks (Quercus spp.) and hickories (Carya spp.), in the forest understory, while shade-tolerant species have proliferated. The goal of this research is to determine how two disturbances, prescribed fire and...

  7. Should Exotic Eucalyptus be Planted in Subtropical China: Insights from Understory Plant Diversity in Two Contrasting Eucalyptus Chronosequences.

    Science.gov (United States)

    Wu, Jianping; Fan, Houbao; Liu, Wenfei; Huang, Guomin; Tang, Jianfu; Zeng, Ruijin; Huang, Jing; Liu, Zhanfeng

    2015-11-01

    Although Eucalyptus is widely planted in South China, whose effects on native biodiversity are unclear. The objective of this study was to quantify the richness and composition of understory plants in two contrasting Eucalyptus chronosequences in South China. One was in Zhangzhou City with plantation age of 2, 4, and 6 years after clear-cutting Chinese fir forests, while the other was in Heshan City with plantation age of 2, 3, and 24 years that reforested on barren lands. Results showed that the richness of understory plants and functional groups was not significantly altered in the Zhangzhou chronosequence, while increased in the 24-year-old plantations, with a significantly larger proportion of woody plants than the younger plantations for the Heshan chronosequence. Moreover, a higher richness of woody plants accompanied by a lower richness of herbaceous species was detected in the Zhangzhou chronosequence compared with the Heshan one. To balance the need for pulp production and plant diversity conservation, we suggest that intercropping approaches between exotic Eucalyptus plantations and native forests should be considered in the fast rotation Eucalyptus plantations. However, Eucalyptus plantations may be used as pioneer species to sustain ecosystem functioning for the degraded lands.

  8. Influence of light and soil moisture on Sierran mixed-conifer understory communities.

    Science.gov (United States)

    Malcolm North; Brian Oakley; Rob Fiegener; Andrew Gray; Michael. Barbour

    2005-01-01

    Sierra Nevada forests have high understory species richness yet we do not know which site factors influence herb and shrub distribution or abundance. We examined the understory of an old-growth mixed-conifer Sierran forest and its distribution in relation to microsite conditions. The forest has high species richness (98 species sampled), most of which are herbs with...

  9. Enraizamento de estacas herbáceas de diferentes espécies de maracujazeiro Rooting of herbaceous cutting of different passion fruit plant species

    Directory of Open Access Journals (Sweden)

    Givanildo Roncatto

    2008-12-01

    seedlings by cutting propagation at Passiflora edulis Sims f. flavicarpa Degener and Passiflora alata Dryander commercial species, and at Passiflora giberti N.E.Brown, Passiflora nitida H.B.K. and Passiflora setacea D.C. rootstocks. The trial was conducted under greenhouse condition with 50% of shading and intermittent nebulization chamber conditions. The cuttings were collected from adult plants of the germoplasm bank of the Plant Production Departament of the FCAV/UNESP and others from commercial orchards, like P. edulis f. flavicarpa. The intermediate part of the last growth branches in the growth stage and herbaceous cuttings with 15cm, three nodes and two half leaves were colected on June and October, 2000 and April, 2001. The cuttings were treated with Indolebutyric Acid (IBA in 500, 1000 e 2000mg.L-1 concentrations and without using IBA (control, and cultivated in plastic trays (40x30x10cm with vermiculite during 60 days. The rooting percentage was better for P. edulis f. flavicarpa in spring (October with 76,7% without using IBA (control. P. alata Dryander and P. nitida rooted in different seasons using 500 mg.L-1 of IBA. P. giberti rooted in spring, but without using IBA. The number and lenght of roots was higher in October. The surviving rate, as well as dead cuttings was higher on June 2000. P. setacea did not root.

  10. Facilitation between woody and herbaceous plants that associate with arbuscular mycorrhizal fungi in temperate European forests.

    Science.gov (United States)

    Veresoglou, Stavros D; Wulf, Monika; Rillig, Matthias C

    2017-02-01

    In late-successional environments, low in available nutrient such as the forest understory, herbaceous plant individuals depend strongly on their mycorrhizal associates for survival. We tested whether in temperate European forests arbuscular mycorrhizal (AM) woody plants might facilitate the establishment of AM herbaceous plants in agreement with the mycorrhizal mediation hypothesis. We used a dataset spanning over 400 vegetation plots in the Weser-Elbe region (northwest Germany). Mycorrhizal status information was obtained from published resources, and Ellenberg indicator values were used to infer environmental data. We carried out tests for both relative richness and relative abundance of herbaceous plants. We found that the subset of herbaceous individuals that associated with AM profited when there was a high cover of AM woody plants. These relationships were retained when we accounted for environmental filtering effects using path analysis. Our findings build on the existing literature highlighting the prominent role of mycorrhiza as a coexistence mechanism in plant communities. From a nature conservation point of view, it may be possible to promote functional diversity in the forest understory through introducing AM woody trees in stands when absent.

  11. Understory biomass from southern pine forests as a fuel source

    Energy Technology Data Exchange (ETDEWEB)

    Ku, T.T. [Univ. of Arkansas, Monticello, AR (United States); Baker, J.B. [USDA Forest Service, Monticello, AR (United States)

    1993-12-31

    The energy crisis in the US in the late 1970s led to accelerated research on renewable energy resources. The use of woody biomass, harvested from pine forests in the southern US, as a renewable energy source would not only provide an efficient energy alternative to forest industries, but its use would also reduce understory competition and accelerate growth of overstory crop trees. This study was initiated in the early 1980s to investigate the feasibility and applicability of the use of understory vegetation as a possible energy fuel resource. All woody understory vegetation [<14 cm (<5.5 in) in dbh], on 0.2 ha (0.5 ac) plots that represented a range of stand/site conditions of pine stands located in twelve southern Arkansas counties and two northern Louisiana parishes were characterized, quantified, and harvested. Based on the biomass yield from 720 subplots nested within 40 main plots, the top five dominant species in the understory, based on number and size were: Red maple, red oaks, pines, sweetgum, and winged elm. Some other species occurring, but in smaller proportions, were flowering dogwood, beautyberry, white oaks, black gum, wax myrtle, hickories, persimmon, and ashes. Most of these species are deciduous hardwoods that provide high BTU output upon burning. The average yield of chipped understory biomass was 23.5 T/ha with no difference occurring between summer and winter harvests. A predictive model of understory biomass production was developed using a step-wise multivariate regression analysis. In relation to forest type, high density pine stands produced 53% more understory biomass than high density pine-hardwood stands. The average moisture content of biomass was significantly lower when harvested in winter than when harvested in summer.

  12. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    Science.gov (United States)

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment.

  13. Understory vegetation response to mechanical mastication and other fuels treatments in a ponderosa pine forest

    Science.gov (United States)

    Jeffrey M. Kane; J. Morgan Varner; Eric E. Knapp

    2010-01-01

    Questions: What influence does mechanical mastication and other fuel treatments have on: (1) canopy and forest floor response variables that influence understory plant development; (2) initial understory vegetation cover, diversity, and composition; and (3) shrub and non-native species density in a secondgrowth ponderosa pine forest....

  14. Mapping snags and understory shrubs for LiDAR based assessment of wildlife habitat suitability

    Science.gov (United States)

    Sebastian Martinuzzi; Lee A. Vierling; William A. Gould; Michael J. Falkowski; Jeffrey S. Evans; Andrew T. Hudak; Kerri T. Vierling

    2009-01-01

    The lack of maps depicting forest three-dimensional structure, particularly as pertaining to snags and understory shrub species distribution, is a major limitation for managing wildlife habitat in forests. Developing new techniques to remotely map snags and understory shrubs is therefore an important need. To address this, we first evaluated the use of LiDAR data for...

  15. Dry coniferous forest restoration and understory plant diversity: The importance of community heterogeneity and the scale of observation

    Science.gov (United States)

    Erich Kyle Dodson; David W. Peterson

    2010-01-01

    Maintaining understory plant species diversity is an important management goal as forest restoration and fuel reduction treatments are applied extensively to dry coniferous forests of western North America. However, understory diversity is a function of both local species richness (number of species in a sample unit) and community heterogeneity (beta diversity) at...

  16. Research Note Pilot survey to assess sample size for herbaceous ...

    African Journals Online (AJOL)

    A pilot survey to determine sub-sample size (number of point observations per plot) for herbaceous species composition assessments, using a wheel-point apparatus applying the nearest-plant method, was conducted. Three plots differing in species composition on the Zululand coastal plain were selected, and on each plot ...

  17. ESTABLISHMENT TECHNIQUES FOR TROPICAL LEGUMES IN THE UNDERSTORY OF A EUCALYPTUS PLANTATION

    Directory of Open Access Journals (Sweden)

    Maria Luiza Franceschi Nicodemo

    2015-04-01

    Full Text Available This study evaluated establishment methods for a mixture of herbaceous forage legumes [Centrosema acutifolium, Clitoria ternatea, Pueraria phaseoloides, Stylosanthes Campo Grande (Stylosanthes capitata + S. macrocephala, Calopogonium mucunoides, Lablab purpureus, Arachis pintoi, and Aeschynomene villosa] under the shade of an Eucalyptus grandis plantation submitted to thinning (40% 8 years after planting in Anhembi, São Paulo (22°40'S, 48°10'W, altitude of 455 m. The experiment started in December 2008 and consisted of the comparison of the following four types of seed incorporation by light disc harrowing: (1 broadcast sowing without seed incorporation; disc harrowing before (2 or after (3 planting, and (4 disc harrowing before and after planting. Ninety days after planting, the number of legume plants/m2 and the percentage of ground cover by the plants varied between the treatments tested; however, the treatments had no effect on the dry matter accumulation of forage legumes. Disc harrowing before planting yielded superior results compared to the treatments without disc harrowing and disc harrowing after planting. At the end of the experimental period, the plots contained Arachis, Centrosema, Stylosanthes, and Pueraria. The dry matter accumulated by Centrosema corresponded to 73% of total dry matter yield of the plots. The participation of Arachis, Centrosema and Stylosanthes in final dry matter composition of the plots varied according to establishment method. The advantages of the use of species mixtures rather than monocultures in the understory of forest plantations were discussed.

  18. Examining spring phenology of forest understory using digital photography

    Science.gov (United States)

    Liang Liang; Mark D. Schwartz; Songlin Fei

    2011-01-01

    Phenology is an important indicator of forest health in relation to energy/nutrient cycles and species interactions. Accurate characterization of forest understory phenology is a crucial part of forest phenology observation. In this study, ground plots set up in a temperate mixed forest in Wisconsin were observed with a visible-light digital camera during spring 2007....

  19. Evergreen understory dynamics in Coweeta forest, North Carolina

    Science.gov (United States)

    M.M. Dobbs; Albert J. Parker

    2004-01-01

    A number of studies have elucidated the distributional patterns of various components of Southern Appalachian forests. The evergreen understory here is composed largely of a dominant ericaceous shrub, Rhododendron maximum L., which is believed to be expanding and inhibiting the development of other species with consequent impacts on overall forest...

  20. Functional leaf attributes predict litter decomposition rate in herbaceous plants

    NARCIS (Netherlands)

    Cornelissen, J. H C; Thompson, K.

    1997-01-01

    We tested the hypothesis that functional attributes of living leaves provide a basis for predicting the decomposition rate of leaf litter. The data were obtained from standardized screening tests on 38 British herbaceous species. Graminoid monocots had physically tougher leaves with higher silicon

  1. Enxertia de maracujazeiro-azedo em estacas herbáceas enraizadas de espécies de passifloras nativas Grafting of passion fruit on rooted-herbaceous cuttings of wild passiflora species

    Directory of Open Access Journals (Sweden)

    Renata da Costa Chaves

    2004-04-01

    Full Text Available As doenças provocadas por patógenos do solo em maracujazeiro constituem-se em um dos principais problemas para essa cultura no Brasil. Uma das alternativas de controle dessas doenças seria a utilização de porta-enxertos resistentes. Várias espécies de passifloras nativas vêm apresentando resistência a essas doenças, mas a utilização destas como porta-enxertos oriundos de sementes tem sido dificultada pelas diferenças de diâmetro entre o porta-enxerto e o enxerto da espécie comercial, o que não aconteceria caso fossem utilizadas as estacas herbáceas como porta-enxerto. No presente experimento, utilizaram-se estacas herbáceas retiradas da parte mediana de ramos de plantas de Passiflora setacea (acesso EC-PS 1, P. nitida (acesso EC-PN 1, P. caerulea (acesso EC-PC 1, P. actinia (acesso EC-PA 1 e de um híbrido F1 entre P. setacea x P. edulis f. flavicarpa comercial e tratadas com ácido naftaleno acético (ANA a 500 mg/L e mantidas em câmaras de nebulização. As enxertias do tipo "garfagem lateral no topo" foram efetuadas aos 40; 55 e 70 dias após a coleta e plantio das estacas, utilizando garfos de uma única planta de maracujazeiro-azedo. As avaliações foram efetuadas aos 145 e 150 dias após o plantio das estacas, determinando-se a porcentagem de pegamento da enxertia e de enxertos brotados e o comprimento do broto do enxerto. A produção de mudas por enxertia em estacas herbáceas enraizadas de Passiflora nitida e do híbrido F1 (P. setacea x P. edulis f. flavicarpa foi tecnicamente viável.The soil born diseases cause expressive losses in passion fruit crops in Brazil. The use of resistant rootstocks is an alternative to control these diseases. Several wild species of Passifloraceae have presented resistance to soil born pathogens, but their utilization as rootstock from seeds has been limited mainly by differences of thickness between the rootstock and the graft of the commercial cultivars. These limitations could be

  2. Facilitative and Inhibitory Effect of Litter on Seedling Emergence and Early Growth of Six Herbaceous Species in an Early Successional Old Field Ecosystem

    Directory of Open Access Journals (Sweden)

    Qiang Li

    2014-01-01

    Full Text Available In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m−2, litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland.

  3. Facilitative and inhibitory effect of litter on seedling emergence and early growth of six herbaceous species in an early successional old field ecosystem.

    Science.gov (United States)

    Li, Qiang; Yu, Pujia; Chen, Xiaoying; Li, Guangdi; Zhou, Daowei; Zheng, Wei

    2014-01-01

    In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m(-2), litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland.

  4. Rainforest understory beetles of the Neotropics, Mizotrechus Bates 1872, a generic synopsis with descriptions of new species from Central America and northern South America (Coleoptera, Carabidae, Perigonini).

    Science.gov (United States)

    Erwin, Terry L

    2011-01-01

    Information on the single previously described species, Mizotrechus novemstriatus Bates 1872 (type locality: Brazil - Amazonas, Tefé), is updated and 17 new species for the genus from Nicaragua, Costa Rica, Panamá, Colombia, Venezuela, and Guyane are described. The species records in the literature and on determined specimens in some collections of Mizotrechus novemstriatus Bates from Central America are not that species; currently, Mizotrechus novemstriatus is known only from its type locality in Amazonian Brazil. For the new species described, their known general distributions are as follows: Mizotrechus batesisp. n. (Guyane), Mizotrechus bellorumsp. n. (Guyane), Mizotrechus bruleisp. n. (Guyane), Mizotrechus belevederesp. n. (Guyane), Mizotrechus costaricensissp. n. (Costa Rica), Mizotrechus dalensisp. n. (Guyane), Mizotrechus edithpiafaesp. n. (provenance unknown), Mizotrechus fortunensissp. n. (Panamá), Mizotrechus gorgona. sp. n. (Colombia), Mizotrechus grossussp. n. (Guyane), Mizotrechus jefesp. n. (Panamá), Mizotrechus marielaforetaesp. n. (Guyane), Mizotrechus minutussp. n. (Guyane), Mizotrechus neblinensissp. n. (Guyane, Venezuela), Mizotrechus poirierisp. n. (Guyane), and Mizotrechus woldaisp. n. (Panamá). Long-term use of flight intercept traps in Guyane provided so many new species that apparently the use of FITs is the way to collect adults of this taxon, previously known from very few specimens. Many more species of this genus can be expected to be discovered throughout the Neotropics; the present contribution is a preliminary synopsis with identification key and adult images of all known species. Likely numerous species are yet to be discovered throughout tropical climes.

  5. Rainforest understory beetles of the Neotropics: Mizotrechus Bates 1872, a generic synopsis with descriptions of new species from Central America and northern South America (Coleoptera, Carabidae, Perigonini

    Directory of Open Access Journals (Sweden)

    Terry Erwin

    2011-11-01

    Full Text Available Information on the single previously described species, Mizotrechus novemstriatus Bates 1872 (type locality: Brazil – Amazonas, Tefé, is updated and 17 new species for the genus from Nicaragua, Costa Rica, Panamá, Colombia, Venezuela, and Guyane are described. The species records in the literature and on determined specimens in some collections of M. novemstriatus Bates from Central America are not that species; currently, M. novemstriatus is known only from its type locality in Amazonian Brazil. For the new species described, their known general distributions are as follows: Mizotrechus batesi sp. n. (Guyane, Mizotrechus bellorum sp. n. (Guyane, Mizotrechus brulei sp. n. (Guyane, Mizotrechus belevedere sp. n. (Guyane, Mizotrechus costaricensis sp. n. (Costa Rica, Mizotrechus dalensi sp. n. (Guyane, Mizotrechus edithpiafae sp. n. (provenance unknown, Mizotrechus fortunensis sp. n. (Panamá, Mizotrechus gorgona. sp. n. (Colombia, Mizotrechus grossus sp. n. (Guyane, Mizotrechus jefe sp. n. (Panamá, Mizotrechus marielaforetae sp. n. (Guyane, Mizotrechus minutus sp. n. (Guyane, Mizotrechus neblinensis sp. n. (Guyane, Venezuela, Mizotrechus poirieri sp. n. (Guyane, and Mizotrechus woldai sp. n. (Panamá. Long-term use of flight intercept traps in Guyane provided so many new species that apparently the use of FITs is the way to collect adults of this taxon, previously known from very few specimens. Many more species of this genus can be expected to be discovered throughout the Neotropics; the present contribution is a preliminary synopsis with identification key and adult images of all known species. Likely numerous species are yet to be discovered throughout tropical climes.

  6. Stable oxygen isotope and flux partitioning demonstrates understory of an oak savanna contributes up to half of ecosystem carbon and water exchange

    Directory of Open Access Journals (Sweden)

    Maren eDubbert

    2014-10-01

    Full Text Available Semi-arid ecosystems contribute about 40% to global net primary production (GPP even though water is a major factor limiting carbon uptake. Evapotranspiration (ET accounts for up to 95% of the water loss and in addition, vegetation can also mitigate drought effects by altering soil water distribution. Hence, partitioning of carbon and water fluxes between the soil and vegetation components is crucial to gain mechanistic understanding of vegetation effects on carbon and water cycling. However, the possible impact of herbaceous vegetation in savanna type ecosystems is often overlooked. Therefore, we aimed at quantifying understory vegetation effects on the water balance and productivity of a Mediterranean oak savanna. ET and net ecosystem CO2 exchange (NEE were partitioned based on flux and stable oxygen isotope measurements and also rain infiltration was estimated.The understory vegetation contributed importantly to total ecosystem ET and GPP with a maximum of 43% and 51%, respectively. It reached water-use efficiencies (WUE; ratio of carbon gain by water loss similar to cork-oak trees. The understory vegetation inhibited soil evaporation (E and, although E was large during wet periods, it did not diminish WUE during water-limited times. The understory strongly increased soil water infiltration, specifically following major rain events. At the same time, the understory itself was vulnerable to drought, which led to an earlier senescence of the understory growing under trees as compared to open areas, due to competition for water. Thus, beneficial understory effects are dominant and contribute to the resilience of this ecosystem. At the same time the vulnerability of the understory to drought suggests that future climate change scenarios for the Mediterranean basin threaten understory development. This in turn will very likely diminish beneficial understory effects like infiltration and ground water recharge and therefore ecosystem resilience to

  7. The formation of dense understory layers in forests worldwide: consequences and implications for forest dynamics, biodiversity, and succession

    Science.gov (United States)

    Alejandro A. Royo; Walter P. Carson

    2010-01-01

    Alterations to natural herbivore and disturbance regimes often allow a select suite of forest understory plant species to dramatically spread and form persistent, mono-dominant thickets. Following their expansion, this newly established understory canopy can alter tree seedling recruitment rates and exert considerable control over the rate and direction of secondary...

  8. Multi-scale spatial controls of understory vegetation in Douglas-fir–western hemlock forests of western Oregon, USA

    Science.gov (United States)

    Julia I. Burton; Lisa M. Ganio; Klaus J. Puettmann

    2014-01-01

    Forest understory vegetation is influenced by broad-scale variation in climate, intermediate scale variation in topography, disturbance and neighborhood interactions. However, little is known about how these multi-scale controls interact to influence observed spatial patterns. We examined relationships between the aggregated cover of understory plant species (%...

  9. Herbaceous forage and selection patterns by ungulates across varying herbivore assemblages in a South African savanna

    NARCIS (Netherlands)

    Treydte, A.C.; Baumgartner, S.; Heitkonig, I.M.A.; Grant, C.C.; Getz, W.M.

    2013-01-01

    Herbivores generally have strong structural and compositional effects on vegetation, which in turn determines the plant forage species available. We investigated how selected large mammalian herbivore assemblages use and alter herbaceous vegetation structure and composition in a southern African

  10. Bromatologic composition of the herbaceous species of the Northeastern Brazil Caatinga Composição bromatológica de espécies herbáceas da caatinga

    Directory of Open Access Journals (Sweden)

    D.S. Silva

    2011-04-01

    Full Text Available The objective of this work was to evaluate the chemical composition of the pool and of four species of caatinga herbaceous vegetation in the rainy and dry seasons. The experiment was conducted in three selected shrub areas at different levels of conservation. Four samples of each species (Arachis pintoi, Boerhavia diffusa, Heliotropium ternatum, Aristida adscensionis were collected in each area and from a pool of species for determination of bromatologic composition. In the dry season, only the pool of species and the grass Aristida adscensionis were evaluated. There was a significant effect of the studied area on the chemical composition of all analyzed species. The nutrient content found in the dry matter (DM and the digestibility of the pool of species indicate that caatinga herbs presented improved quality in the rainy season. The qualitative variables of the studied species were most heterogeneous due to the variability found in caatinga. Conservation conditions in caatinga and season of the year influence bromatologic composition of the species Arachis pintoi, Boerhavia diffusa L., Heliotropium ternatum Vahl. Aristida adscensionis L. and of a pool of typical species found in Caatinga.Com o objetivo de avaliar a composição bromatológica do pool e de quatro espécies da vegetação herbácea da caatinga nos períodos chuvoso e seco foi conduzido um experimento em três áreas selecionadas de caatinga, com níveis diferenciados de conservação. Em cada área, foram colhidas quatro amostras de cada espécie (Arachis pintoi, Boerhavia diffusa, Heliotropium ternatum, Aristida adscensionis e de um pool de espécies, para determinação da composição bromatológica. Na época seca foram avaliados somente o pool de espécies e a gramínea Aristida adscensionis. Houve efeito significativo da área amostrada na composição bromatológica de todas as espécies analisadas. Os teores de nutrientes na matéria seca (MS e a digestibilidade do pool

  11. Influences of image resolution on herbaceous root morphological parameters

    Directory of Open Access Journals (Sweden)

    ZHANG Zeyou

    2014-06-01

    Full Text Available Root images of four herbaceous species (including Plantago virginica,Solidago canadensis,Conyza canadensis and Erigeron philadelphicus were obtained by using EPSON V7000 scanner with different resolutions.Root morphological parameters including root length,diameter,volume and area were determined by using a WinRhizo root analyzing software.The results show a distinct influence of image resolution on root morphological parameter.For different herbaceous species,the optimal resolutions of root images,which would produce an acceptable precision with relative short time,vary with different species.For example,a resolution of 200 dpi was recommended for the root images of Plantago virginica and S.Canadensis, while 400 dpi for Conyza canadensis and Erigeron philadelphicus.

  12. Biochemical methane potential and anaerobic biodegradability of non-herbaceous and herbaceous phytomass in biogas production

    DEFF Research Database (Denmark)

    Triolo, Jin Mi; Pedersen, Lene; Qu, Haiyan

    2012-01-01

    The suitability of municipal plant waste for anaerobic digestion was examined using 57 different herbaceous and non-herbaceous samples. Biochemical methane potential (BMP) and anaerobic biodegradability were related to the degree of lignification and crystallinity of cellulose. The BMP of herbace...

  13. Aphid (Hemiptera: Aphididae) species determined on herbaceous ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... Western Blacksea Region of Turkey. Azize Toper Kaygin1* ... insects in all over the world as they are an important disease vectors and direct ... 2005; Aslan and Uygun,. 2005; Unal and Ozcan, 2005; Kaygin et al., 2008a,b;.

  14. Effect of overstory on the seasonal variability of understory herbs in ...

    African Journals Online (AJOL)

    In order to study the structure of herbaceous biodiversity and its effect factors in ... The highest species richness was in June, when spring ephemeral, early and ... PPFD, soil water was the key connection between the tree- and shrub layer.

  15. The cost of silage harvest and transport systems for herbaceous crops

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow, A.; Downing, M. [Oak Ridge National Lab., TN (United States); Butler, J. [Butler (James), Tifton, GA (United States)

    1996-12-31

    Some of the highest yielding herbaceous biomass crops are thick- stemmed species. Their relatively high moisture content necessitates they be handled and stored as silage rather than hay bales or modules. This paper presents estimated costs of harvesting and transporting herbaceous crops as silage. Costs are based on an engineering- economic approach. Equipment costs are estimated by combining per hour costs with the hours required to complete the operation. Harvest includes severing, chopping, and blowing stalks into a wagon or truck.

  16. The influence of canopy-layer composition on understory plant diversity in southern temperate forests

    Directory of Open Access Journals (Sweden)

    Luciana Mestre

    2017-05-01

    Full Text Available Background Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning. Despite their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests. The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types (monospecific deciduous Nothofagus pumilio (Np, monospecific evergreen Nothofagus betuloides (Nb, and mixed N. pumilio-N. betuloides (M forests, comparing also between two geographical locations (coast and mountain to estimate differences at landscape level. Results We recorded 46 plant species: 4 ferns, 12 monocots, and 30 dicots. Canopy-layer composition influences the herb-layer structure and diversity in two different ways: while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant assemblage. Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse. Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and integrate. Moreover, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species. Conclusions Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain sites. Maintaining the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant

  17. Sucesso reprodutivo de espécies distílicas de psychotria (rubiaceae em sub-bosque de floresta atlântica Reproductive success of distylous species of psychotria (rubiaceae of understory atlantic forest

    Directory of Open Access Journals (Sweden)

    Celice Alexandre Silva

    2013-04-01

    Full Text Available As espécies distílicas Psychotria conjugens, P. hastisepala e P. sessilis (Rubiaceae são típicas de sub-bosques sombreados. Ocorrem no maior fragmento de Floresta Estacional Semidecidual de Viçosa, Minas Gerais, Sudeste brasileiro - a Mata do Paraíso, com 194 ha. A distilia caracteriza-se pela presença dos morfos florais longistilos (L e brevistilos (B em indivíduos distintos e pela dependência de polinizações intermorfos (L x B ou B x L para a produção de frutos; é esperada a proporção equilibrada (isopletia dos indivíduos na população. Foram objetivos deste trabalho verificar, nas espécies citadas, a proporção dos morfos florais em uma área de 7 ha e a dependência por polinizadores, testando a incompatibilidade intramorfos (L x L e B x B por meio de polinizações manuais in vivo, a viabilidade dos grãos de pólen e dimorfismo dos grãos entre os morfos florais; e quantificar as produções de frutos e de sementes por morfo. Os morfos florais das espécies se encontram em proporções equilibradas. Houve incompatibilidade e a viabilidade dos grãos de pólen foi alta (> 64%. Verificou-se dimorfismo dos grãos, e os maiores diâmetros foram os de B. As produções de frutos e de sementes (uma ou duas dos morfos de P. sessilis e de P. conjugens foram semelhantes e, em P. hastisepala, foram maiores em B. Na Mata do Paraíso, as condições adequadas, como o hábitat, a isopletia e a atuação de polinizadores, são fatores que parecem favorecer o sucesso reprodutivo e, consequentemente, a manutenção local das espécies estudadas.The distylous species of Psychotria conjugens, P. hastisepala e P. sessilis (Rubiaceae are typical of understory shady. It occurs in the largest fragment (194 ha of semideciduous forest in Viçosa, Minas Gerais State, southeastern Brazil, where the present study was carried out. The distyly is characterized by the presence of pin (L and thrum (B floral morphs in different individual and the

  18. Enhancement of understory productivity by asynchronous phenology with overstory competitors in a temperate deciduous forest.

    Science.gov (United States)

    Jolly, William M; Nemani, Ramakrishna; Running, Steven W

    2004-09-01

    Some saplings and shrubs growing in the understory of temperate deciduous forests extend their periods of leaf display beyond that of the overstory, resulting in periods when understory radiation, and hence productivity, are not limited by the overstory canopy. To assess the importance of the duration of leaf display on the productivity of understory and overstory trees of deciduous forests in the north eastern United States, we applied the simulation model, BIOME-BGC with climate data for Hubbard Brook Experimental Forest, New Hampshire, USA and mean ecophysiological data for species of deciduous, temperate forests. Extension of the overstory leaf display period increased overstory leaf area index (LAI) by only 3 to 4% and productivity by only 2 to 4%. In contrast, extending the growing season of the understory relative to the overstory by one week in both spring and fall, increased understory LAI by 35% and productivity by 32%. A 2-week extension of the growing period in both spring and fall increased understory LAI by 53% and productivity by 55%.

  19. [Effects of understory removal on soil greenhouse gas emissions in Carya cathayensis stands].

    Science.gov (United States)

    Liu, Juan; Chen, Xue-shuang; Wu, Jia-sen; Jiang, Pei-kun; Zhou, Guo-mo; Li, Yong-fu

    2015-03-01

    CO2, N2O and CH4 are important greenhouse gases, and soils in forest ecosystems are their important sources. Carya cathayensis is a unique tree species with seeds used for high-grade dry fruit and oil production. Understory vegetation management plays an important role in soil greenhouse gases emission of Carya cathayensis stands. A one-year in situ experiment was conducted to study the effects of understory removal on soil CO2, N2O and CH4 emissions in C. cathayensis plantation by closed static chamber technique and gas chromatography method. Soil CO2 flux had a similar seasonal trend in the understory removal and preservation treatments, which was high in summer and autumn, and low in winter and spring. N2O emission occurred mainly in summer, while CH4 emission showed no seasonal trend. Understory removal significantly decreased soil CO, emission, increased N2O emission and CH4 uptake, but had no significant effect on soil water soluble organic carbon and microbial biomass carbon. The global warming potential of soil greenhouse gases emitted in the understory removal. treatment was 15.12 t CO2-e . hm-2 a-1, which was significantly lower than that in understory preservation treatment (17.04 t CO2-e . hm-2 . a-1).

  20. A Phenology-Based Method for Monitoring Woody and Herbaceous Vegetation in Mediterranean Forests from NDVI Time Series

    Directory of Open Access Journals (Sweden)

    David Helman

    2015-09-01

    Full Text Available We present an efficient method for monitoring woody (i.e., evergreen and herbaceous (i.e., ephemeral vegetation in Mediterranean forests at a sub pixel scale from Normalized Difference Vegetation Index (NDVI time series derived from the Moderate Resolution Imaging Spectroradiometer (MODIS. The method is based on the distinct development periods of those vegetation components. In the dry season, herbaceous vegetation is absent or completely dry in Mediterranean forests. Thus the mean NDVI in the dry season was attributed to the woody vegetation (NDVIW. A constant NDVI value was assumed for soil background during this period. In the wet season, changes in NDVI were attributed to the development of ephemeral herbaceous vegetation in the forest floor and its maximum value to the peak green cover (NDVIH. NDVIW and NDVIH agreed well with field estimates of leaf area index and fraction of vegetation cover in two differently structured Mediterranean forests. To further assess the method’s assumptions, understory NDVI was retrieved form MODIS Bidirectional Reflectance Distribution Function (BRDF data and compared with NDVIH. After calibration, leaf area index and woody and herbaceous vegetation covers were assessed for those forests. Applicability for pre- and post-fire monitoring is presented as a potential use of this method for forest management in Mediterranean-climate regions.

  1. Fuels planning: science synthesis and integration; environmental consequences fact sheet 10: The Understory Response Model

    Science.gov (United States)

    Steve Sutherland; Melanie Miller

    2005-01-01

    The Understory Response Model is a species-specific computer model that qualitatively predicts change in total species biomass for grasses, forbs, and shrubs after thinning, prescribed fire, or wildfire. The model examines the effect of fuels management on plant survivorship and reproduction. This fact sheet identifies the intended users and uses, required inputs, what...

  2. Classification and ordination of understory vegetation using multivariate techniques in the Pinus wallichiana forests of Swat Valley, northern Pakistan

    Science.gov (United States)

    Rahman, Inayat Ur; Khan, Nasrullah; Ali, Kishwar

    2017-04-01

    An understory vegetation survey of the Pinus wallichiana-dominated temperate forests of Swat District was carried out to inspect the structure, composition and ecological associations of the forest vegetation. A quadrat method of sampling was used to record the floristic and phytosociological data necessary for the analysis using 300 quadrats of 10 × 10 m each. Some vegetation parameters viz. frequency and density for trees (overstory vegetation) as well as for the understory vegetation were recorded. The results revealed that in total, 92 species belonging to 77 different genera and 45 families existed in the area. The largest families were Asteraceae, Rosaceae and Lamiaceae with 12, ten and nine species, respectively. Ward's agglomerative cluster analysis for tree species resulted in three floristically and ecologically distinct community types along different topographic and soil variables. Importance value indices (IVI) were also calculated for understory vegetation and were subjected to ordination techniques, i.e. canonical correspondence analysis (CCA) and detrended correspondence analysis (DCA). DCA bi-plots for stands show that most of the stands were scattered around the centre of the DCA bi-plot, identified by two slightly scattered clusters. DCA for species bi-plot clearly identified three clusters of species revealing three types of understory communities in the study area. Results of the CCA were somewhat different from the DCA showing the impact of environmental variables on the understory species. CCA results reveal that three environmental variables, i.e. altitude, slope and P (mg/kg), have a strong influence on distribution of stands and species. Impact of tree species on the understory vegetation was also tested by CCA which showed that four tree species, i.e. P. wallichiana A.B. Jackson, Juglans regia Linn., Quercus dilatata Lindl. ex Royle and Cedrus deodara (Roxb. ex Lamb.) G. Don, have strong influences on associated understory vegetation. It

  3. Seedling Composition and Facilitative Effects of the Herbaceous Layer in a Monsoon-Affected Forest in Nanjenshan, Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Su-Wei Fan

    2010-11-01

    Full Text Available Tree seedlings play an important role in forest regeneration. To understand the factors that control seedling establishment, we (1 compared the composition patterns of tree seedlings and their corresponding overstories, (2 examined the relationships between seedling composition and environmental factors and (3 evaluated the interaction (competition or facilitation between seedlings and herbaceous layer in a wind-stressed forest in Nanjenshan, southern Taiwan. In the study plot, seedling abundance of canopy, subcanopy and shrub species (with true leaves and < 1 cm diameter at breast height and coverage of herbaceous species (including herbaceous species, climbers and tree ferns ≤ ca. 1 m in height were investigated on three transects with a total of 180 contiguous 5 × 5 m quadrats. Clustering classification and ordination methods were used to reveal the tree seedling composition patterns and the relationships between seedling composition and environmental factors. Correlation coefficients were computed between herbaceous coverage and seedling abundance among herb-seedling species pairs and between tall (≥ 1 m high/short (< 0.5 m high herbs and seedlings pairs to test the herb-seedling interaction. The spatial distribution of tree seedlings presented a perfect match to the overstory vegetation pattern. There was a strong relationship among seedling composition, herbaceous composition and topographic features, especially exposure to monsoon winds. Because of the absence of strong correlations between herbaceous structure/species and seedling abundances, the strong linkage in spatial patterns between seedling and herbaceous compositions suggests that certain plant species in the study plot have similar responses to the monsoon exposure. Our results also indicated that seedlings < 1 cm in diameter were strongly influenced by wind stress, similar to the response of the overstory composition, and that the facilitative/competitive effects of the

  4. Can the Understory Affect the Hymenoptera Parasitoids in a Eucalyptus Plantation?

    Directory of Open Access Journals (Sweden)

    Onice Teresinha Dall'Oglio

    Full Text Available The understory in forest plantations can increase richness and diversity of natural enemies due to greater plant species richness. The objective of this study was to test the hypothesis that the presence of the understory and climatic season in the region (wet or dry can increase the richness and abundance of Hymenoptera parasitoids in Eucalyptus plantations, in the municipality of Belo Oriente, Minas Gerais State, Brazil. In each eucalyptus cultivation (five areas of cultivation ten Malaise traps were installed, five with the understory and five without it. A total of 9,639 individuals from 30 families of the Hymenoptera parasitoids were collected, with Mymaridae, Scelionidae, Encyrtidae and Braconidae being the most collected ones with 4,934, 1,212, 619 and 612 individuals, respectively. The eucalyptus stands with and without the understory showed percentage of individuals 45.65% and 54.35% collected, respectively. The understory did not represent a positive effect on the overall abundance of the individuals Hymenoptera in the E. grandis stands, but rather exerted a positive effect on the specific families of the parasitoids of this order.

  5. Can the Understory Affect the Hymenoptera Parasitoids in a Eucalyptus Plantation?

    Science.gov (United States)

    Dall’Oglio, Onice Teresinha; Ribeiro, Rafael Coelho; Ramalho, Francisco de Souza; Fernandes, Flávio Lemes; Wilcken, Carlos Frederico; de Assis Júnior, Sebastião Lourenço; Rueda, Rosa Angélica Plata; Serrão, José Eduardo; Zanuncio, José Cola

    2016-01-01

    The understory in forest plantations can increase richness and diversity of natural enemies due to greater plant species richness. The objective of this study was to test the hypothesis that the presence of the understory and climatic season in the region (wet or dry) can increase the richness and abundance of Hymenoptera parasitoids in Eucalyptus plantations, in the municipality of Belo Oriente, Minas Gerais State, Brazil. In each eucalyptus cultivation (five areas of cultivation) ten Malaise traps were installed, five with the understory and five without it. A total of 9,639 individuals from 30 families of the Hymenoptera parasitoids were collected, with Mymaridae, Scelionidae, Encyrtidae and Braconidae being the most collected ones with 4,934, 1,212, 619 and 612 individuals, respectively. The eucalyptus stands with and without the understory showed percentage of individuals 45.65% and 54.35% collected, respectively. The understory did not represent a positive effect on the overall abundance of the individuals Hymenoptera in the E. grandis stands, but rather exerted a positive effect on the specific families of the parasitoids of this order. PMID:26954578

  6. Herbaceous plants as filters: Immobilization of particulates along urban street corridors

    International Nuclear Information System (INIS)

    Weber, Frauke; Kowarik, Ingo; Säumel, Ina

    2014-01-01

    Among air pollutants, particulate matter (PM) is considered to be the most serious threat to human health. Plants provide ecosystem services in urban areas, including reducing levels of PM by providing a surface for deposition and immobilization. While previous studies have mostly addressed woody species, we focus on herbaceous roadside vegetation and assess the role of species traits such as leaf surface roughness or hairiness for the immobilization of PM. We found that PM deposition patterns on plant surfaces reflect site-specific traffic densities and that strong differences in particulate deposition are present among species. The amount of immobilized PM differed according to particle type and size and was related to specific plant species traits. Our study suggests that herbaceous vegetation immobilizes a significant amount of the air pollutants relevant to human health and that increasing biodiversity of roadside vegetation supports air filtration and thus healthier conditions along street corridors. -- Highlights: • We assessed PM immobilization by common urban herbaceous roadside species. • PM deposition was related to traffic density and plant species traits. • Amount of PM deposited differed according to particle type and size. • Increasing biodiversity of roadside vegetation supports air filtration. -- Herbaceous urban roadside vegetation immobilizes particulate matter relevant to human health, thus supporting healthier conditions next to busy roads

  7. Understory plant diversity in riparian alder-conifer stands after logging in southeast Alaska.

    Science.gov (United States)

    Robert L. Deal

    1997-01-01

    Stand structure, tree height growth, and understory plant diversity were assessed in five mixed alder-conifer stands after logging in southeast Alaska. Tree species composition ranged from 7- to 91-percent alder, and basal area ranged from 30 to 55 m2/ha. The alder exhibited rapid early height growth, but recent growth has slowed considerably. Some conifers have...

  8. Physiological, morphological and allocational plasticity in understory deciduous trees: importance of plant size and light availability.

    Science.gov (United States)

    Delagrange, Sylvain; Messier, Christian; Lechowicz, Martin J; Dizengremel, Pierre

    2004-07-01

    In a 4-year study, we investigated changes in leaf physiology, crown morphology and whole-tree biomass allocation in seedlings and saplings of shade-tolerant sugar maple (Acer saccharum Marsh.) and intermediate shade-tolerant yellow birch (Betula alleghaniensis Britt.) growing in natural understory light (0.5 to 35% of full sunlight) or in understory light reduced by 50% with shade nets to simulate the effect of gap closure. Leaf physiological parameters were mainly influenced by the light gradient, whereas crown morphological and whole-tree allocational parameters were mainly influenced by tree size. No single physiological, morphological or allocational trait was identified that could explain the difference in shade tolerance between the species. Yellow birch had higher growth rates, biomass allocation to branches and leaf physiological plasticity and lower crown morphological plasticity in unmodified understory light than sugar maple. Sugar maple did not display significant physiological plasticity, but showed variation with tree size in both crown morphology and whole-tree biomass allocation. When sugar maple was small, a greater proportion of whole-tree biomass was allocated to roots. However, physiological differences between the species decreased with decreasing light and most morphological and allocational differences tended to disappear with increasing tree size, suggesting that many species differences in shade-tolerance are expressed mainly during the seedling stage. Understory trees of both species survived for 4 years under shade nets, possibly because of higher plasticity when small and the use of stored reserves when taller. Copyright 2004 Heron Publishing

  9. Post-Fire Peat Land Understory Plant in Rimba Panjang, Sumatera, Indonesia

    Science.gov (United States)

    Firdaus, L. N.; Nursal; Wulandari, Sri; Syafi'i, Wan; Fauziah, Yuslim

    2017-12-01

    The existence of understory plants during early post-fire succession is essential in term of natural post-fire ecological restoration. More than fifty percent of fire incidents in Riau, Sumatera, Indonesia occurred in shallow peat lands which have the huge impact on vegetation damage. This study aims to explore the understory plants species and diversity in post-fire peat land at Rimba Panjang, Kampar Regency, Sumatera, Indonesia. By using survey method, the observations were conducted on 150 plots which were distributed randomly over four locations based on the year after fire: 2009, 2014, 2015 and 2016. We found respectively 12, 14, 19 and 17 species at that sites with respective Shannon Wiener diversity index were 1.72, 2.00, 2.14 and 2.40. All the sites were dominated by Stenochlaena palustris (Burm.). Coverage percentage of understory vegetation were respectively 28.87%, 25.50%, 51.60% and 54.13%. Overall, we found 31 species of 17 familia. The result showed that the species composition, diversity index and coverage percentage of understory plant are likely to decrease in line with the length of time after the fire. Post peatland fires in Rimba Panjang are still having the characteristics of the peat swamp habitat which was dominated by Stenochlaena palustris (Burm.). Ecological restoration of that habitat is still possible, but it is necessary to consider technological and socio-economical aspects of local communities.

  10. Effects of understory prescribed burning on shortleaf pine (Pinus echinata Mill.)/mixed-hardwood forests

    Science.gov (United States)

    Katherine J. Elliott; James M. Vose

    2005-01-01

    We examined the effects of a single dormant season fire on overstory and understory species diversity and composition and tree seedling regeneration patterns the first and second years following a prescribed burn in the Conasauga River Watershed of southeastern Tennessee and northern Georgia. We asked: Can a single dormant season fire initiate a trajectory of overstory...

  11. Herbaceous vegetation in thinned and defoliated forest stands in north central West Virginia

    Science.gov (United States)

    S. L. C. Fosbroke; D. Feicht; R. M. Muzika

    1995-01-01

    Herbaceous vegetation was inventoried in 1992 and 1993 in eight Appalachian mixed hardwood stands ( 50% basal area/acre in oak species) in north central West Virginia. Vegetation was sampled on 20 6-foot radius plots per stand twice each growing season (once during late spring to sample spring ephemeral...

  12. Thermogravimetric analysis of forest understory grasses

    Science.gov (United States)

    Thomas Elder; John S. Kush; Sharon M. Hermann

    2011-01-01

    Forest understory grasses are of significance in the initiation, establishment and maintenance of fire, whether used as a management tool or when occurring as wildfire. The fundamental thermal properties of such grasses are critical to their behavior in fire situations and have been investigated in the current work by the application of thermogravimetric analysis (TGA...

  13. Understory bamboo discrimination using a winter image

    NARCIS (Netherlands)

    Wang, T.; Skidmore, A.K.; Toxopeus, A.G.; Liu, X.

    2009-01-01

    In this study, a new approach is presented that combines forest phenology and Landsat vegetation indices to estimate evergreen understory bamboo coverage in a mixed temperate forest. It was found that vegetation indices, especially the normalized difference vegetation index (NDVI) derived from

  14. Effects of past logging and grazing on understory plant communities in a montane Colorado forest

    Science.gov (United States)

    Fornwalt, P.J.; Kaufmann, M.R.; Huckaby, L.S.; Stohlgren, T.J.

    2009-01-01

    Throughout Pinus ponderosa-Pseudotsuga menziesii forests of the southern Colorado Front Range, USA, intense logging and domestic grazing began at the time of Euro-American settlement in the late 1800s and continued until the early 1900s. We investigated the long-term impacts of these settlement-era activities on understory plant communities by comparing understory composition at a historically logged and grazed site to that of an environmentally similar site which was protected from past use. We found that species richness and cover within functional groups rarely differed between sites in either upland or riparian areas. Multivariate analyses revealed little difference in species composition between sites on uplands, though compositional differences were apparent in riparian zones. Our findings suggest that settlement-era logging and grazing have had only minor long-term impacts on understories of upland Front Range P. ponderosa-P. menziesii forests, though they have had a greater long-term influence on riparian understories, where these activities were likely the most intense. ?? 2008 Springer Science+Business Media B.V.

  15. Nitrogen-addition effects on leaf traits and photosynthetic carbon gain of boreal forest understory shrubs.

    Science.gov (United States)

    Palmroth, Sari; Bach, Lisbet Holm; Nordin, Annika; Palmqvist, Kristin

    2014-06-01

    Boreal coniferous forests are characterized by fairly open canopies where understory vegetation is an important component of ecosystem C and N cycling. We used an ecophysiological approach to study the effects of N additions on uptake and partitioning of C and N in two dominant understory shrubs: deciduous Vaccinium myrtillus in a Picea abies stand and evergreen Vaccinium vitis-idaea in a Pinus sylvestris stand in northern Sweden. N was added to these stands for 16 and 8 years, respectively, at rates of 0, 12.5, and 50 kg N ha(-1) year(-1). N addition at the highest rate increased foliar N and chlorophyll concentrations in both understory species. Canopy cover of P. abies also increased, decreasing light availability and leaf mass per area of V. myrtillus. Among leaves of either shrub, foliar N content did not explain variation in light-saturated CO2 exchange rates. Instead photosynthetic capacity varied with stomatal conductance possibly reflecting plant hydraulic properties and within-site variation in water availability. Moreover, likely due to increased shading under P. abies and due to water limitations in the sandy soil under P. sylvestris, individuals of the two shrubs did not increase their biomass or shift their allocation between above- and belowground parts in response to N additions. Altogether, our results indicate that the understory shrubs in these systems show little response to N additions in terms of photosynthetic physiology or growth and that changes in their performance are mostly associated with responses of the tree canopy.

  16. Impacts of Extreme Events on Phenology: Drought-Induced Changes in Productivity of Mixed Woody-Herbaceous Ecosystems

    Science.gov (United States)

    Rich, P. M.; Breshears, D. D.; White, A. B.

    2006-12-01

    Ecosystem responses to key climate drivers are reflected in phenological dynamics such as the timing and degree of "greenup" that integrate responses over spatial scales from individual plants to ecosystems. This integration is clearest in ecosystems dominated by a single species or life form, such as seasonally dynamic grasslands or more temporally constant evergreen forests. Yet many ecosystems have substantial contribution of cover from both herbaceous and woody evergreen plants. Responses of mixed woody- herbaceous ecosystems to climate are of increasing concern due to their extensive nature, the potential for such systems to yield more complex responses than those dominated by a single life form, and projections that extreme climate and weather events will increase in frequency and intensity with global warming. We present responses of a mixed woody-herbaceous ecosystem type to an extreme event: regional scale piñon pine mortality following an extended drought and the subsequent herbaceous greenup following the first wet period after the drought. This example highlights how reductions in greenness of the slower, more stable evergreen woody component can rapidly be offset by increases associated with resources made available to the relatively more responsive herbaceous component. We hypothesize that such two-phase phenological responses to extreme events are characteristic of many mixed woody-herbaceous ecosystems.

  17. Performance of tropical legumes grown as understory of a eucalypt plantation in a seasonally dry area of the Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    Maria Luiza F. Nicodemo

    2015-09-01

    Full Text Available Nine tropical legumes were grown outside the canopy and in the understory of an 8-year-old Eucalyptus grandis stand in order to assess their seasonal production and forage quality for 4 evaluation periods. Incident photosynthetically active radiation in the understory was 18% of that outside the canopy. In the understory, production of Lablab purpureus, Centrosema schiedeanum, Clitoria ternatea, Pueraria phaseoloides, Alysicarpus vaginalis, Aeschynomene villosa, Estilosantes Campo Grande (Stylosanthes capitata + S. macrocephala, Calopogonium mucunoides and Arachis pintoi was <1 kg/ha/d for most samples. Even considering this low production, the large area available for animal production in forest plantations might justify the interest in legumes because of their high nutritive value. Lablab purpureus produced the greatest amount of dry matter in the understory in the establishment phase (12.1 kg/ha/d, but did not persist. It could be a suitable candidate for a cover legume species mixture to provide early growth. Centrosema schiedeanum developed rapidly and showed a high capacity for ground cover (>70% and persistence, and had high nitrogen concentration, thus demonstrating good potential for protecting soils and promoting nutrient cycling in forest plantations. Another species with potential is A. pintoi, which established slowly but towards the end of the experiment showed moderate to high understory ground cover.Keywords: Dry matter production, forage quality, shade, silvopastoral system.DOI: 10.17138/TGFT(3151-160

  18. Site quality influence over understory plant diversity in old-growth and harvested Nothofagus pumilio forests

    Directory of Open Access Journals (Sweden)

    E. A. Gallo

    2013-04-01

    Full Text Available Aim of study: The effects and interactions of shelterwood forest harvesting and site qualities over understory plant species diversity and composition were compared among primary and harvested Nothofagus pumilio forests.Area of study: Tierra del Fuego (Argentina, on three pure conditions (one and six year-old harvested, and primary without previous harvesting forests and three site qualities (high, medium and low.Material and Methods: Understory richness and cover (% were registered in five replicates of 1 hectare each per treatment. Taxonomic species were classified in categories (groups, origin and life forms. Two-way ANOVAs and multivariate analyses were conducted.Main results: Shelterwood harvesting and site quality significantly influenced understory cover and richness, which allow the introduction of native and exotic species and increasing of dicot and monocot covers. In dicots, monocots, exotics and total groups, higher richness and covers were related to time. Meanwhile, cover reached similar high values in all site qualities on dicot, native and total groups. On the other hand, monocot and exotic richness and cover remain similar in primary and recently harvested forests, and greatly increased in old harvested forests. Mosses and ferns were among the most sensitive groups.Research highlights: Impacts of shelterwood cut depend on site quality of the stands and time since harvesting occurs. For this, different site quality stands should received differential attention in the development of conservation strategies, as well as variations in the shelterwood implementation (as irregularity and patchiness should be considered to better promote understory plant species conservation inside managed areas.Key words: plant species conservation; years after harvesting; forest management; Tierra del Fuego.

  19. Herbaceous land plants as a renewable energy source for Puerto Rico

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, A.G.

    1980-01-01

    Herbaceous tropical plants are a renewable energy source of major importance to many tropical nations. They convert the radiant energy of sunlight to chemical energy, which is stored in plant tissues (cellulose, hemicellulose, lignin) and fermentable solids (sugars, starches). Because all tropical plants do this - even those commonly regarded as weeds - they constitute an inexpensive, renewable, and domestic alternative to foreign fossil energy. The vast majority of herbaceous tropical plants have never been cultivated for food, fiber, or energy. A major screening program would be needed to identify superior species and the most effective roles they can play in a domestic energy industry. Other herbaceous plants, such as sugarcane and tropical forage grasses, have been cultivated for centuries as agricultural commodities. As energy crops, important revisions in management will be needed to maximize their energy yield. Two broad groups of herbaceous plants are seen to have an immediate potential for reducing Puerto Rico's reliance on imported fossil fuels: the tropical grasses (of which sugarcane is the dominant member) and the tropical legumes. Managed for its maximum growth potential, sugarcane is an excellent source of boiler fuel, fermentation substrates, cellulosic feedstocks, and the sweetener sucrose. Other tropical grasses store relatively little extractable sugar while equaling or moderately surpassing sugarcane in yield of cellulosic dry matter. The latter might soon become an economical source of fermentation substrates. Certain legume species are also very effective producers of biomass. Herbaceous tropical legumes are perceived as a potential source of biological nitrogen for energy crops unable to utilize nitrogen from the atmosphere.

  20. Herbaceous land plants as a renewable energy source for Puerto Rico

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, A G

    1980-01-01

    Herbaceous tropical plants are a renewable energy source of major importance to many tropical nations. They convert the radiant energy of sunlight to chemical energy, which is stored in plant tissues (cellulose, hemicellulose, lignin) and fermentable solids (sugars, starches). Because all tropical plants do this - even those commonly regarded as weeds - they constitute an inexpensive, renewable, and domestic alternative to foreign fossil energy. The vast majority of herbaceous tropical plants have never been cultivated for food, fiber, or energy. A major screening program would be needed to identify superior species and the most effective roles they can play in a domestic energy industry. Other herbaceous plants, such as sugarcane and tropical forage grasses, have been cultivated for centuries as agricultural commodities. As energy crops, important revisions in management will be needed to maximize their energy yield. Two broad groups of herbaceous plants are seen to have an immediate potential for reducing Puerto Rico's reliance on imported fossil fuels: the tropical grasses (of which sugarcane is the dominant member) and the tropical legumes. Managed for its maximum growth potential, sugarcane is an excellent source of boiler fuel, fermentation substrates, cellulosic feedstocks, and the sweetener sucrose. Other tropical grasses store relatively little extractable sugar while equaling or moderately surpassing sugarcane in yield of cellulosic dry matter. The latter might soon become an economical source of fermentation substrates. Certain legume species are also very effective producers of biomass. Herbaceous tropical legumes are perceived as a potential source of biological nitrogen for energy crops unable to utilize nitrogen from the atmosphere.

  1. Evaluating environmental consequences of producing herbaceous crops for bioenergy

    International Nuclear Information System (INIS)

    McLaughlin, S.B.

    1995-01-01

    The environmental costs and benefits of producing bioenergy crops can be measured both in kterms of the relative effects on soil, water, and wildlife habitat quality of replacing alternate cropping systems with the designated bioenergy system, and in terms of the quality and amount of energy that is produced per unit of energy expended. While many forms of herbaceous and woody energy crops will likely contribute to future biofuels systems, The Dept. of Energy's Biofuels Feedstock Development Program (BFDP), has chosen to focus its primary herbaceous crops research emphasis on a perennial grass species, switchgrass (Panicum virgatum), as a bioenergy candidate. This choice was based on its high yields, high nutrient use efficiency, and wide geographic distribution, and also on its poistive environmental attributes. The latter include its positive effects on soil quality and stabiity, its cover value for wildlife, and the lower inputs of enerty, water, and agrochemicals required per unit of energy produced. A comparison of the energy budgets for corn, which is the primary current source of bioethanol, and switchgrass reveals that the efficiency of energy production for a perennial grass system can exceed that for an energy intensive annual row crop by as much as 15 times. In additions reductions in CO 2 emission, tied to the energetic efficiency of producing transportation fuels, are very efficient with grasses. Calculated carbon sequestration rates may exceed those of annual crops by as much as 20--30 times, due in part to carbon storage in the soil. These differences have major implications for both the rate and efficiency with which fossil energy sources can be replaced with cleaner burning biofuels

  2. Evaluating environmental consequences of producing herbaceous crops for bioenergy

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, S.B.

    1995-12-31

    The environmental costs and benefits of producing bioenergy crops can be measured both in kterms of the relative effects on soil, water, and wildlife habitat quality of replacing alternate cropping systems with the designated bioenergy system, and in terms of the quality and amount of energy that is produced per unit of energy expended. While many forms of herbaceous and woody energy crops will likely contribute to future biofuels systems, The Dept. of Energy`s Biofuels Feedstock Development Program (BFDP), has chosen to focus its primary herbaceous crops research emphasis on a perennial grass species, switchgrass (Panicum virgatum), as a bioenergy candidate. This choice was based on its high yields, high nutrient use efficiency, and wide geographic distribution, and also on its poistive environmental attributes. The latter include its positive effects on soil quality and stabiity, its cover value for wildlife, and the lower inputs of enerty, water, and agrochemicals required per unit of energy produced. A comparison of the energy budgets for corn, which is the primary current source of bioethanol, and switchgrass reveals that the efficiency of energy production for a perennial grass system can exceed that for an energy intensive annual row crop by as much as 15 times. In additions reductions in CO{sub 2} emission, tied to the energetic efficiency of producing transportation fuels, are very efficient with grasses. Calculated carbon sequestration rates may exceed those of annual crops by as much as 20--30 times, due in part to carbon storage in the soil. These differences have major implications for both the rate and efficiency with which fossil energy sources can be replaced with cleaner burning biofuels.

  3. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

    Directory of Open Access Journals (Sweden)

    Anne C S McIntosh

    Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

  4. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

    Science.gov (United States)

    McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  5. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests

    Science.gov (United States)

    McIntosh, Anne C. S.; Macdonald, S. Ellen; Quideau, Sylvie A.

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  6. Unique competitive effects of lianas and trees in a tropical forest understory.

    Science.gov (United States)

    Wright, Alexandra; Tobin, Mike; Mangan, Scott; Schnitzer, Stefan A

    2015-02-01

    Lianas are an important component of tropical forests, contributing up to 25% of the woody stems and 35% of woody species diversity. Lianas invest less in structural support but more in leaves compared to trees of similar biomass. These physiological and morphological differences suggest that lianas may interact with neighboring plants in ways that are different from similarly sized trees. However, the vast majority of past liana competition studies have failed to identify the unique competitive effects of lianas by controlling for the amount of biomass removed. We assessed liana competition in the forest understory over the course of 3 years by removing liana biomass and an equal amount of tree biomass in 40 plots at 10 sites in a secondary tropical moist forest in central Panama. We found that growth of understory trees and lianas, as well as planted seedlings, was limited due to competitive effects from both lianas and trees, though the competitive impacts varied by species, season, and size of neighbors. The removal of trees resulted in greater survival of planted seedlings compared to the removal of lianas, apparently related to a greater release from competition for light. In contrast, lianas had a species-specific negative effect on drought-tolerant Dipteryx oleifera seedlings during the dry season, potentially due to competition for water. We conclude that, at local scales, lianas and trees have unique and differential effects on understory dynamics, with lianas potentially competing more strongly during the dry season, and trees competing more strongly for light.

  7. Functional role of the herbaceous layer in eastern deciduous forest

    Science.gov (United States)

    Katherine J. Elliott; James M. Vose; Jennifer D. Knoepp; Barton D. Clinton; Brian D. Kloeppel

    2014-01-01

    The importance of the herbaceous layer in regulating ecosystem processes in deciduous forests is generally unknown. We use a manipulative study in a rich, mesophytic cove forest in the southern Appalachians to test the following hypotheses: (i) the herbaceous functional group (HFG) in mesophytic coves accelerates carbon and nutrient cycling, (ii) high litter quality...

  8. Diversity patterns of ground beetles and understory vegetation in mature, secondary, and plantation forest regions of temperate northern China

    NARCIS (Netherlands)

    Zou, Yi; Sang, Weiguo; Wang, Shunzhong; Warren-Thomas, Eleanor; Liu, Yunhui; Yu, Zhenrong; Wang, Changliu; Axmacher, Jan Christoph

    2015-01-01

    Plantation and secondary forests form increasingly important components of the global forest cover, but our current knowledge about their potential contribution to biodiversity conservation is limited. We surveyed understory plant and carabid species assemblages at three distinct regions in

  9. Family richness and biomass of understory invertebrates in early and late successional habitats of northern New Hampshire

    Science.gov (United States)

    Matthew K. Wilson; Winsor H. Lowe; Keith Nislow

    2014-01-01

    In the northeastern United States, many vertebrate species rely on early successional forest habitats (ESHs). ESHs may also support higher invertebrate diversity and abundance than late successional habitats (LSHs). We assessed the differences in family-level richness and biomass of understory terrestrial invertebrates during the summer season in paired ESH (3-7 years...

  10. Understory fuel variation at the Carolina Sandhills National Wildlife Refuge: a description of chemical and physical properties

    Science.gov (United States)

    Evelyn S. Wenk; G. Geoff Wang; Joan L. Walker

    2013-01-01

    Upland forest in the Carolina Sandhills National Wildlife Refuge is characterized by a longleaf pine (Pinus palustris) canopy with a variable understory and ground-layer species composition. The system was historically maintained by fire and has been managed with prescribed fire in recent decades. A management goal is to reduce turkey oak (...

  11. Airborne laser scanner (LiDAR) proxies for understory light conditions

    DEFF Research Database (Denmark)

    Alexander, Cici; Moeslund, Jesper Erenskjold; Bøcher, Peder Klith

    2013-01-01

    to community structure. Angular canopy closure is more closely related to the direct and indirect light experienced by a plant or an animal than vertical canopy cover, but more challenging to estimate. We used airborne laser scanner (ALS) data to estimate canopy cover for 210 5-m radius vegetation plots......Canopy cover and canopy closure are two closely related measures of vegetation structure. They are used for estimating understory light conditions and their influence on a broad range of biological components in forest ecosystems, from the demography and population dynamics of individual species...... of azimuth and zenith angle intervals which contained points. We compared these estimates with field-based estimates using densiometer for 60 vegetation plots in forest. Finally, we compared ALS-based estimates of canopy cover and canopy closure to field-based estimates of understory light, based...

  12. Impacts of environmental factors on the climbing behaviors of herbaceous stem-twiners.

    Science.gov (United States)

    Hu, Liang; Chen, Youfang; Liu, Meicun

    2017-11-01

    The curvature of the helical trajectory formed by herbaceous stem-twiners has been hypothesized to be constant on uniformly sized cylindrical supports and remains constant on different supports varying in diameter. However, experimental studies on the constant curvature hypothesis have been very limited. Here, we tested the hypothesis in a series of experiments on five herbaceous stem-twiners ( Ipomoea triloba , Ipomoea nil , Phaseolus vulgaris , Vigna unguiculata, and Mikania micrantha ). We investigated how internode characteristics (curvature [β], diameter [ d ], and length [ L ]) and success rate (SR) of twining shoots would be affected by support thickness ( D ), temperature ( T ), illumination, and support inclination. The results showed that: (1) the SR of tested species decreased, but d increased with increasing support thickness. The β of the twining shoots on erect cylindrical poles was not constant, but it decreased with increasing d or support thickness. (2) The SR of tested species was not obviously reduced under low-temperature conditions, but their β was significantly higher and d significantly lower when temperature was more than 5°C lower. (3) The SR , d, and L of two tested Ipomoea species significantly declined, but β increased under 50% shading stress. (4) The curvatures of upper semicycles of I. triloba shoots on 45° inclined supports were not significantly different from curvatures of those shoots climb on erect supports, whereas the curvatures of lower semicycles were 40%-72% higher than curvatures of upper semicycles. Synthesis : Our study illustrates that stem curvatures of a certain herbaceous stem-twiners are not constant, but rather vary in response to external support, temperature, and illumination conditions. We speculate that herbaceous stem-twiners positively adapt to wide-diameter supports by thickening their stems and by reducing their twining curvatures. This insight helps us better understand climbing processes and

  13. Potencial de quatro espécies herbáceas forrageiras para fitorremediação de solo contaminado por arsênio Potential of four herbaceous forage species for phytoremediation of a soil contaminated with arsenic

    Directory of Open Access Journals (Sweden)

    Roseli Freire de Melo

    2009-04-01

    fitoestabilização e, ou, na revegetação de áreas contaminadas por As, uma vez que apresentaram tolerância a esse elemento. Por se tratar de espécies forrageiras, quando utilizadas para esses fins, cuidados especiais são necessários, como o isolamento da área, para evitar a entrada do elemento na cadeia trófica.The decontamination of soils and substrates contaminated with arsenic through phytoremediation techniques has attracted increasing interest of researchers and specialists of environmental sciences. This study aimed to evaluate the potential of the species townsville stylo (Stylosanthes humilis HBK, forage peanut (Arachis pintoi Krapov. & Gregory, oat (Avena strigosa Schreb, and ryegrass (Lolium multiflorum Lam. for phytoremediation of arsenic-contaminated soils. Samples of a Red Yellowh Latossol (Oxisol were incubated with different doses of arsenic (0; 50; 100 and 200 mg dm-3. After this incubation period, the four species were sown and, after germination, soil samples were fertilized accordingly. Sixty five days after sowing, plants were evaluated for height and biomass weight of roots and shoots. Arsenic content in young, intermediate, and old leaves, stem and roots and the As-translocation index (IT were determined. By regression analysis we estimated the critical contents for available arsenic (TC in soil which reduced the biomass production by 50 %. The species differed in As-tolerance; no morphologic symptoms of As toxicity were observed for ryegrass, forage peanut and townsville stylo. The TC values for oat and ryegrass were high. In forage peanut and townsville stylo plants the absorption and shoot translocation of arsenic were higher, but the potential of forage peanut for phytoremediation programs is greater. Ryegrass, peanut and stylo plants can be used in phytostabilization and / or the revegetation of As-contaminated areas. When forage species are used with phytoremediation purposes, special care is needed, such as the isolation of the area, to

  14. Dense understory dwarf bamboo alters the retention of canopy tree seeds

    Science.gov (United States)

    Qian, Feng; Zhang, Tengda; Guo, Qinxue; Tao, Jianping

    2016-05-01

    Tree seed retention is thought to be an important factor in the process of forest community regeneration. Although dense understory dwarf bamboo has been considered to have serious negative effects on the regeneration of forest community species, little attention has been paid to the relationship between dwarf bamboo and seed retention. In a field experiment we manipulated the density of Fargesia decurvata, a common understory dwarf bamboo, to investigate the retention of seeds from five canopy tree species in an evergreen and deciduous broad-leaved mixed forest in Jinfoshan National Nature Reserve, SW China. We found that the median survival time and retention ratio of seeds increased with the increase in bamboo density. Fauna discriminately altered seed retention in bamboo groves of different densities. Arthropods reduced seed survival the most, and seeds removed decreased with increasing bamboo density. Birds removed or ate more seeds in groves of medium bamboo density and consumed fewer seeds in dense or sparse bamboo habitats. Rodents removed a greater number of large and highly profitable seeds in dense bamboo groves but more small and thin-husked seeds in sparse bamboo groves. Seed characteristics, including seed size, seed mass and seed profitability, were important factors affecting seed retention. The results suggested that dense understory dwarf bamboo not only increased seeds concealment and reduced the probability and speed of seed removal but also influenced the trade-off between predation and risk of animal predatory strategies, thereby impacting the quantity and composition of surviving seeds. Our results also indicated that dense understory dwarf bamboo and various seed characteristics can provide good opportunities for seed storage and seed germination and has a potential positive effect on canopy tree regeneration.

  15. Cutting and resprouting of Detarium microcarpum and herbaceous forage availability in a semiarid environment in Burkina Faso

    NARCIS (Netherlands)

    Rietkerk, M.G.; Blijdorp, R.R.S.; Slingerland, M.

    1998-01-01

    The tree-shrub savanna ‘Forêt Classée de Nazinon’ (Burkina Faso) is submitted to a management of grazing and rotational cutting of Detarium microcarpum. This species resprouts after cutting. In order to investigate whether this silvopastoral land use system is sustainable, aboveground herbaceous

  16. Tolerance of herbaceous summer legumes of temporary waterlogging

    Directory of Open Access Journals (Sweden)

    Elsa M. Ciotti

    2014-09-01

    Full Text Available A greenhouse study to evaluate adaptation of 4 herbaceous summer legumes to temporary waterlogging was conducted.  Species evaluated were Desmanthus virgatus and Aeschynomene americana in their vegetative stage, and Macroptilium lathyroides and M. atropurpureum in both vegetative and reproductive stages.  The experimental design was randomized blocks with 5 replications and treatments were:  T0, control; T1, saturation by capillary movement placing pots in buckets of 5 L with 10 cm of permanent water; and T2, flooding, placing pots in buckets of 10 L and a layer of water 5 cm above the soil.  The duration of the water treatments was 7 days. Waterlogging did not affect shoot or root biomass production nor nodulation in A. americana, whereas D. virgatus had its highest dry matter production in saturated soil (T1.  In M. lathyroides flooding tolerance was more evident in the reproductive than in the vegetative stage, probably due to more production of adventitious roots and formation of aerenchymatic tissue.  Macroptilium atropurpureum showed adaptation to temporary flooding.  Survival and quick recovery of these species would confirm their potential as forages for temporarily waterlogged soils.Keywords: Forage legumes, flooding, Aeschynomene americana, Desmanthus virgatus, Macroptilium lathyroides, Northeast Argentina.DOI: 10.17138/TGFT(2278-286

  17. Understory Structure and Vascular Plant Diversity in Naturally Regenerated Deciduous Forests and Spruce Plantations on Similar Clear-Cuts: Implications for Forest Regeneration Strategy Selection

    Directory of Open Access Journals (Sweden)

    ZhiQiang Fang

    2014-04-01

    Full Text Available The active effect of natural regeneration on understory vegetation and diversity on clear-cut forestlands, in contrast to conifer reforestation, is still controversial. Here we investigated differences in understory vegetation by comparing naturally regenerated deciduous forests (NR and reforested spruce plantations (SP aged 20–40 years on 12 similar clear-cuts of subalpine old-growth spruce-fir forests from the eastern Tibetan Plateau. We found that 283 of the 334 vascular plant species recorded were present in NR plots, while only 264 species occurred in SP plots. This was consistent with richer species, higher cover, and stem (or shoot density of tree seedlings, shrubs, and ferns in the NR plots than in the SP plots. Moreover, understory plant diversity was limited under dense canopy cover, which occurred more frequently in the SP plots. Our findings implied that natural deciduous tree regeneration could better preserve understory vegetation and biodiversity than spruce reforestation after clear-cutting. This result further informed practices to reduce tree canopy cover for spruce plantations or to integrate natural regeneration and reforestation for clear-cuts in order to promote understory vegetation and species diversity conservation.

  18. The initial phase of a Longleaf Pine-Wiregrass Savanna restoration: species establishment and community responses.

    Energy Technology Data Exchange (ETDEWEB)

    Aschenbach, Todd, A; Foster, Bryan, L.; Imm, Donald, W.

    2010-09-01

    AbstractAbstract The significant loss of the longleaf pine-wiregrass ecosystem in the southeastern United States has serious implications for biodiversity and ecosystem functioning. In response to this loss, we have initiated a long-term and landscape-scale restoration experiment at the 80,125 ha (310 mi2) Department of Energy Savannah River Site (SRS) located near Aiken, South Carolina. Aristida beyrichiana (wiregrass), an important and dominant grass (i.e., a “matrix” species) of the longleaf pine savanna understory, and 31 other herbaceous “non-matrix” species were planted at six locations throughout SRS in 2002 and 2003. Of the 36,056 transplanted seedlings, 75% were still alive in June 2004, while mean 1–2 year survival across all planted species was 48%. Lespedeza hirta (hairy lespedeza) exhibited the greatest overall survival per 3 ×3 m cell at 95%, whereas Schizachyrium spp. (little bluestem) exhibited the greatest mean cover among individual species at 5.9%. Wiregrass survival and cover were significantly reduced when planted with non-matrix species. Aggregate cover of all planted species in restored cells averaged 25.9% in 2006. High rates of survival and growth of the planted species resulted in greater species richness (SR), diversity, and vegetative cover in restored cells. Results suggest that the loss of the longleaf pine-wiregrass ecosystem may be ameliorated through restoration efforts and illustrate the positive impact of restoration plantings on biodiversity and vegetative cover.

  19. Feeding habits of Carabidae (Coleoptera associated with herbaceous plants and the phenology of coloured cotton

    Directory of Open Access Journals (Sweden)

    Danilo Henrique da Matta

    2017-04-01

    Full Text Available The carabids (Coleoptera: Carabidae are recognized as polyphagous predators and important natural enemies of insect pests. However, little is known about the feeding habits of these beetles. In this work, we determine the types of food content in the digestive tracts of nine species of Carabidae associated with herbaceous plants and different growth stages of coloured cotton. The food contents were evaluated for beetles associated with the coloured cotton cv. BRS verde, Gossypium hirsutum L. latifolium Hutch., adjacent to weed plants and the flowering herbaceous plants (FHPs Lobularia maritima (L., Tagetes erecta L., and Fagopyrum esculentum Moench. The digestive tract analysis indicated various types of diets and related arthropods for Abaris basistriata, Galerita brasiliensis, Scarites sp., Selenophorus alternans, Selenophorus discopunctatus and Tetracha brasiliensis. The carabids were considered to be polyphagous predators, feeding on different types of prey.

  20. Conundrums in mixed woody-herbaceous plant systems

    CSIR Research Space (South Africa)

    House, JI

    2003-11-01

    Full Text Available -form communities, the novel, complex, nonlinear behaviour of mixed tree-grass systems cannot be accounted for by simply studying or modelling woody and herbaceous components independently. A more robust understanding requires addressing three fundamental conundrums...

  1. Understory Vegetative Diversity of Post-Thinned Pine Plantations Treated with Fertilizer, Fire and Herbicide in East Texas

    Directory of Open Access Journals (Sweden)

    Brian P. Oswald

    2009-01-01

    Full Text Available This study assessed biodiversity in the understory of two pine plantations where different management tools (fertilizer, prescribed burning, and herbicide application were utilized. During three growing seasons, species, percent cover, and number of individuals, and physical characteristics were recorded. Responses to treatment were examined based on comparison of species richness, evenness, diversity, and importance. Two years after treatment, fertilized plots showed a decline in species richness, evenness, and diversity. Prescribed burning and herbicide treatments increased species richness but decreased species evenness, resulting in no change in diversity index. Herbicide treatment reduced the importance of dominant shrubs and increased the importance of disturbance-adapted species.

  2. Understory Vegetative Diversity of Post-Thinned Pine Plantations Treated with Fertilizer, Fire and Herbicide in East Texas

    International Nuclear Information System (INIS)

    Oswald, B.P.; Williams, H.M.; Farrish, K.W.; Ott, B.; Van Kley, J.E.

    2009-01-01

    This study assessed biodiversity in the understory of two pine plantations where different management tools (fertilizer, prescribed burning, and herbicide application) were utilized. During three growing seasons, species, percent cover, and number of individuals, and physical characteristics were recorded. Responses to treatment were examined based on comparison of species richness, evenness, diversity, and importance. Two years after treatment, fertilized plots showed a decline in species richness, evenness, and diversity. Prescribed burning and herbicide treatments increased species richness but decreased species evenness, resulting in no change in diversity index. Herbicide treatment reduced the importance of dominant shrubs and increased the importance of disturbance-adapted species.

  3. Understory Density Characteristics in Several Midlatitude Temperature Forests

    National Research Council Canada - National Science Library

    Krause, Paul

    2003-01-01

    Understory density can have impacts on such military activities as cross-country mobility, bivouac, cover and concealment, and line of sight Airborne sensors provide a fairly good mechanism for measuring the overstory...

  4. Landscape patterns of understory composition and richness across a moisture and nitrogen mineralization gradient in Ohio (U.S.A.) Quercus forests

    Science.gov (United States)

    Todd F. Hutchinson; Ralph E.J. Boerner; Louis R. Iverson; Steve Sutherland; Elaine Kennedy Sutherland

    1999-01-01

    This study quantified relationships of understory vascular plant species composition and richness along environmental gradients over a broad spatial scale in second-growth oak forests in eastern North America. Species frequencies were recorded in 108 25 x 25 m plots in four study sites extending over 70 km in southern Ohio, U.S.A. The plots were stratified into three...

  5. Season and severity of prescribed burn in ponderosa pine forests: implications for understory native and exotic plants.

    Science.gov (United States)

    Becky K. Kerns; Walter G. Thies; Christine G. Niwa

    2006-01-01

    We investigated herbaceous richness and cover in relation to fire season and severity, and other variables, five growing seasons following prescribed fires. Data were collected from six stands consisting of three randomly applied treatments: no burn, spring burn, and fall burn. Fall burns had significantly more exotic/native annual/biennial (an/bi) species and greater...

  6. Towards reconstructing herbaceous biome dynamics and associated precipitation in Africa: insights from the classification of grass morphological traits

    Science.gov (United States)

    Pasturel, Marine; Alexandre, Anne; Novello, Alice; Moctar Dieye, Amadou; Wele, Abdoulaye; Paradis, Laure; Hely, Christelle

    2014-05-01

    Inter-tropical herbaceous ecosystems occupy a 1/5th of terrestrial surface, a half of the African continent, and are expected to extend in the next decades. Dynamic of these ecosystems is simulated with poor accuracy by Dynamic Global Vegetation Models (DGVMs). One of the bias results from the fact that the diversity of the grass layer dominating these herbaceous ecosystems is poorly taken into account. Mean annual precipitation and the length of the dry season are the main constrains of the dynamics of these ecosystems. Conversely, changes in vegetation affect the water cycle. Inaccuracy in herbaceous ecosystem simulation thus impacts simulations of the water cycle (including precipitation) and vice versa. In order to increase our knowledge of the relationships between grass morphological traits, taxonomy, biomes and climatic niches in Western and South Africa, a 3-step methodology was followed: i) values of culm height, leaf length and width of dominant grass species from Senegal were gathered from flora and clustered using the Partition Around Medoids (PAM) method; ii) trait group ability to sign climatic domains and biomes was assessed using Kruskal-Wallis tests; iii) genericity and robustness of the trait groups were evaluated through their application to Chadian and South African botanical datasets. Results show that 8 grass trait groups are present either in Senegal, Chad or South Africa. These 8 trait groups are distributed along mean annual precipitation and dry season length gradients. The combination of three of them allow to discriminate mean annual precipitation domains (1000 mm) and herbaceous biomes (steppes, savannas, South African grasslands and Nama-Karoo). With these results in hand, grass Plant Functional Types (PFTs) of the DGMV LPJ-GUESS will be re-parameterized and particular attention will be given to the herbaceous biomass assigned to each grass trait group. Simultaneously, relationships between grass trait groups and phytolith vegetation

  7. Contributions of understory and/or overstory vegetations to soil microbial PLFA and nematode diversities in Eucalyptus monocultures.

    Directory of Open Access Journals (Sweden)

    Jie Zhao

    Full Text Available Ecological interactions between aboveground and belowground biodiversity have received many attentions in the recent decades. Although soil biodiversity declined with the decrease of plant diversity, many previous studies found plant species identities were more important than plant diversity in controlling soil biodiversity. This study focused on the responses of soil biodiversity to the altering of plant functional groups, namely overstory and understory vegetations, rather than plant diversity gradient. We conducted an experiment by removing overstory and/or understory vegetation to compare their effects on soil microbial phospholipid fatty acid (PLFA and nematode diversities in eucalyptus monocultures. Our results indicated that both overstory and understory vegetations could affect soil microbial PLFA and nematode diversities, which manifested as the decrease in Shannon-Wiener diversity index (H' and Pielou evenness index (J and the increase in Simpson dominance index (λ after vegetation removal. Soil microclimate change explained part of variance of soil biodiversity indices. Both overstory and understory vegetations positively correlated with soil microbial PLFA and nematode diversities. In addition, the alteration of soil biodiversity might be due to a mixing effect of bottom-up control and soil microclimate change after vegetation removal in the studied plantations. Given the studied ecosystem is common in humid subtropical and tropical region of the world, our findings might have great potential to extrapolate to large scales and could be conducive to ecosystem management and service.

  8. Herbaceous Angiosperms Are Not More Vulnerable to Drought-Induced Embolism Than Angiosperm Trees.

    Science.gov (United States)

    Lens, Frederic; Picon-Cochard, Catherine; Delmas, Chloé E L; Signarbieux, Constant; Buttler, Alexandre; Cochard, Hervé; Jansen, Steven; Chauvin, Thibaud; Doria, Larissa Chacon; Del Arco, Marcelino; Delzon, Sylvain

    2016-10-01

    The water transport pipeline in herbs is assumed to be more vulnerable to drought than in trees due to the formation of frequent embolisms (gas bubbles), which could be removed by the occurrence of root pressure, especially in grasses. Here, we studied hydraulic failure in herbaceous angiosperms by measuring the pressure inducing 50% loss of hydraulic conductance (P 50 ) in stems of 26 species, mainly European grasses (Poaceae). Our measurements show a large range in P 50 from -0.5 to -7.5 MPa, which overlaps with 94% of the woody angiosperm species in a worldwide, published data set and which strongly correlates with an aridity index. Moreover, the P 50 values obtained were substantially more negative than the midday water potentials for five grass species monitored throughout the entire growing season, suggesting that embolism formation and repair are not routine and mainly occur under water deficits. These results show that both herbs and trees share the ability to withstand very negative water potentials without considerable embolism formation in their xylem conduits during drought stress. In addition, structure-function trade-offs in grass stems reveal that more resistant species are more lignified, which was confirmed for herbaceous and closely related woody species of the daisy group (Asteraceae). Our findings could imply that herbs with more lignified stems will become more abundant in future grasslands under more frequent and severe droughts, potentially resulting in lower forage digestibility. © 2016 American Society of Plant Biologists. All Rights Reserved.

  9. Factores abióticos que influencian la germinación de seis especies herbáceas de la zona árida de Chile Abiotic factors effects influencing the germination of six herbaceous species of Chilean arid zone

    Directory of Open Access Journals (Sweden)

    Paola A Jara

    2006-09-01

    determinadas por las características ambientales del lugar de procedencia y de la época de germinación naturalThe arid zone of northern Chile has a dry climate that prevents the massive emergency of plant species. The exception to this general trend arises when scarce and irregular rainfall events occur, modify the environmental humidity, and stimulate the germination of seeds. The main external factors that modify the internal nature of the seeds are the hydration time, light, temperature and scarification. In this work two questions were addressed: (a is the germination of seeds of arid zones regulated by independent external factors or by a combined array of stimuli? and (b do exist correspondence between laboratory and in situ germinative conditions?. Seeds of six native and endemic herbaceous species of the north of Chile (Cistanthe salsoloides, Leucocoryne purpurea, Pasithea coerulea, Placea amoena, Schizanthus litoralis y Trichopetalum plumosum were subjected to two germination experiments, with factorial combinations of hydration time, temperature, light, dehydration and scarification. Schizanthus litoralis, was subjected to an aditional scarification-dehydration experiment (experiment 3. Results showed a common response of all the species in study to certain external factors. Maximum germination percentages were reached when exceeding a threshold of 96 h of hydration and at temperatures of 10 to 25 ºC. Light response was species-dependent. Agreement was found between the germinative conditions determined in laboratory and natural conditions of germination. Therefore, the seeds of plant species of arid zones display similar germinative thresholds and the techniques of germination in laboratory must be determined by the environmental characteristics of the place of origin and the time of natural germination

  10. Effect of Single Selection Method on Woody and Herbaceous Plant Biodiversity in Khalil-Mahale Forest, Behshahr

    Directory of Open Access Journals (Sweden)

    Sh. Kazemi

    2015-06-01

    Full Text Available This study was undertaken to investigate the role of forest management in tree diversity, regeneration and vegetation in control and managed parcels of series No. 1 of forestry plan in Khalil-Mahale, Behshahr. Thirty samples with an area of 1000 m2 were systematically and randomly taken with a 100 × 75 m grid in both parcels. In each plot, tree number and species type were recorded. In order to study the vegetation, five micro-plots (1 m2, one in the center and four others in four main directions (half radius from the center of the plot were taken in each plot. The type and percentage of herbaceous species were recorded in each microplot. To count the regeneration in the center of the main plot, circular sample plots with an area of 100 m2 were used. To study and compare the biodiversity in the two plots and to calculate the richness and evenness, the Simpson and Shannon-Wiener diversity indices, Margalef and Menhinic indices and the Pilo index were used, respectively, using PAST software. The results showed that the number of plant species was more in managed plots. The biodiversity of woody and herbaceous plants richness indices and regeneration of tree species were higher in managed plots. In fact, the results showed that forest management using single selection method had different effects on woody species regeneration and diversity of herbaceous and tree species.

  11. BOREAS TE-9 In Situ Understory Spectral Reflectance Within the NSA

    Science.gov (United States)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Supronowicz, Jan; Edwards, Geoffrey; Viau, Alain; Thomson, Keith

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-9 (Terrestrial Ecology) team collected several data sets related to chemical and photosynthetic properties of leaves in boreal forest tree species. Spectral reflection coefficients of the forest understory at the ground level, in three boreal forest sites of Northern Manitoba (56 N latitude and 98 W longitude), were obtained and analyzed in 1994. In particular, angular variation of the reflection coefficients in the old jack pine and young jack pine forests, as well as nadir reflection coefficient in the young aspen forest, were investigated. The complexity of understory composition and the light patterns limited quantitative conclusions; however, a number of interesting trends in the behavior of the measured values can be inferred. In particular, the unique spectral profiles of lichens show very strongly in the old jack pine understory, yet are definitely less conspicuous for young jack pine, and virtually absent in the aspen forest. The angular variation of the reflection coefficient by the young pine understory seems to be significantly toned down by fine-structured branches and their shadows. Our study also indicates how difficult the ground reflection coefficient problem in a forest is, compared to certain previously investigated areas that have a more uniform appearance, such as prairie grassland, bare soil, or agricultural crops. This is due to several factors, generally typical of a forest environment, that may influence the overall understory reflection coefficient, including: (1) a strong diversity of the forest floor due to the presence of dead tree trunks, holes in the ground, patches of different types of vegetation or litter, etc.; (2) pronounced 3-D structures at the ground level, such as shrubs, bushes, and young trees; and (3) an irregular shadow mosaic, which not only varies with the time of the day, causing intensity variations, but likely also effectively modifies the spectrum of the

  12. Dynamics of Understory Shrub Biomass in Six Young Plantations of Southern Subtropical China

    Directory of Open Access Journals (Sweden)

    Yuanqi Chen

    2017-11-01

    Full Text Available Understory shrubs are an important component of forest ecosystems and drive ecosystem processes, such as ecosystem carbon cycling. However, shrub biomass carbon stocks have rarely been reported, which limits our understanding of ecosystem C stock and cycling. In this study, we evaluated carbon accumulation of shrub species using allometric equations based on height and basal diameter in six subtropical plantations at the age of 1, 3, 4 and 6 years. The results showed that plantation type did not significantly affect the total biomass of shrubs, but it significantly affected the biomass of Rhodomyrtus tomentosa, Ilex asprella, Clerodendrum fortunatum and Baeckea frutescens. The biomass of dominant shrub species R. tomentosa, I. asprella, Gardenia jasminoides and Melastoma candidum increased with stand age, while the biomass of C. fortunatum and B. frutescens decreased. The inconsistent biomass-time patterns of different shrub species may be the primary reason for the altered total shrub biomass in each plantation. Consequently, we proposed that R. tomentosa, I. asprella, G. jasminoides and M. candidum could be preferable for understory carbon accumulation and should be maintained or planted because of their important functions in carbon accumulation and high economic values in the young plantations of southern subtropical China.

  13. Response of understory vegetation over 10 years after thinning in an old-growth cedar and cypress plantation overgrazed by sika deer in eastern Japan

    Directory of Open Access Journals (Sweden)

    Atsushi Tamura

    2017-01-01

    Full Text Available Background Forest management strategies such as thinning have long been used to enhance ecosystem functions, especially in plantations. Thinning in plantations with high deer density, however, may not yield a desired increase in understory vegetation because deer graze on germinating plants after thinning. Here, we examine the changes in understory vegetation after thinning in plantations that have been overgrazed by sika deer to provide insight into the effects of thinning on ecosystem functions such as soil conservation and biological diversity. Methods We conducted our survey in the Tanzawa Mountains of eastern Japan. We surveyed the change in understory vegetation within and outside of three deer exclosures on a single slope with three levels of understory vegetation cover: sparse (1%, exclosure “US”, moderate (30%, exclosure “MM”, and dense (80%, exclosure “LD” over 10 years after a 30% thinning of an old-growth cedar and cypress plantation which was overgrazed by sika deer. Results Understory vegetation cover, biomass and species richness increased within and outside the “US” and “MM” exclosures after thinning, and biomass was greater within than outside the exclosures at 10 years after thinning. Unpalatable species dominated both “US” and “MM” exclosures before thinning, and trees and shrubs dominated within the exclosures over time after thinning. In contrast, unpalatable, grazing-tolerant, perennial, and annual species increased outside the “US” and “MM” exclosures. No noticeable changes were observed within and outside the “LD” exclosure when compared with the “US” and “MM” exclosures. Conclusions Our results suggest that thinning a stand by 30% based on volume resulted in an increase in understory vegetation cover mainly composed of both unpalatable and grazing-tolerant species in a plantation forest where understory vegetation is sparse or moderate and sika deer density is high. We

  14. Taxonomic revision and distribution of herbaceous Paramollugo (Molluginaceae in the Eastern Hemisphere

    Directory of Open Access Journals (Sweden)

    Alexander P. Sukhorukov

    2016-10-01

    Full Text Available The genus Paramollugo with the type species Paramollugo nudicaulis (≡Mollugo nudicaulis has recently been described after molecular investigations. Here we report two new endemic Malagasy species: Paramollugo simulans and P. elliotii, and transfer a forgotten New Caledonian endemic Mollugo digyna to Paramollugo (P. digyna. Consequently, the number of Paramollugo species in the Eastern Hemisphere is increased from three to six. Almost all genus representatives (except P. nudicaulis, which has a wide distribution in Southern Asia, Arabia and tropical Africa are endemic to Madagascar, Somalia, or New Caledonia. Since the type of seed coat ornamentation is crucial for species delimitation, a diagnostic key with new taxonomically significant carpological characters and other new traits is provided for all the herbaceous Paramollugo. The distribution patterns of P. nudicaulis s.str., P. simulans and P. elliotii are presented.

  15. Floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viruá National Park, Roraima, Brazil.

    Science.gov (United States)

    Costa, Suzana Maria; Barbosa, Tiago Domingos Mouzinho; Bittrich, Volker; do Amaral, Maria do Carmo Estanislau

    2016-01-01

    We provide and discuss a floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viruá National Park (VNP). The VNP is located in the northern Amazon basin and displays phytophysiognomies distributed in a mosaic where these plants occur, as flooded forests, hydromorphic white-sand savannas, "buritizais" and waterbodies. After expeditions between February/2010 and January/2015 and the analysis of specimens from regional herbaria, we list 207 species of herbaceous and subshrubby aquatic and palustrine angiosperms for the VNP, distributed in 85 genera in 37 families. We recorded six new occurrences for Brazil, two for the northern Brazilian region and 21 for Roraima state. These new occurrences, added to the other species listed here, highlight the floristic similarity between the study site and the Guiana Shield, an adjacent phytogeographical unit and geologically related to the origin of white-sand savannas.

  16. Floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viruá National Park, Roraima, Brazil

    OpenAIRE

    Costa, Suzana Maria; Barbosa, Tiago Domingos Mouzinho; Bittrich, Volker; do Amaral, Maria do Carmo Estanislau

    2016-01-01

    Abstract We provide and discuss a floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viru? National Park (VNP). The VNP is located in the northern Amazon basin and displays phytophysiognomies distributed in a mosaic where these plants occur, as flooded forests, hydromorphic white-sand savannas, ?buritizais? and waterbodies. After expeditions between February/2010 and January/2015 and the analysis of specimens from regional herbaria, we list 207 species of herb...

  17. The impact of grazing on forage quality of the herbaceous ...

    African Journals Online (AJOL)

    Reports on research conducted in the Mamoro cork oak forest of Morocco to describe the impacts of sheep grazing in March, April, May and June of 1987 and 1988 on seasonal changes in forage quality of the herbaceous vegetation. The study showed that trends in herbage quality were related mainly to plant maturity.

  18. Predicting the Chemical composition of herbaceous legumes using ...

    African Journals Online (AJOL)

    Predicting the Chemical composition of herbaceous legumes using Near Infrared Reflectance Spectroscopy. J F Mupangwa, N Berardo, N T Ngongoni, J H Topps, H Hamudikuwanda, M Ordoardi. Abstract. (Journal of Applied Science in Southern Africa: 2000 6(2): 107-114). http://dx.doi.org/10.4314/jassa.v6i2.16844.

  19. Herbaceous weed control in loblolly pine plantations using flazasulfuron

    Science.gov (United States)

    Andrew W. Ezell; Jimmie L. Yeiser

    2015-01-01

    A total of 13 treatments were applied at four sites (two in Mississippi and two in Texas) to evaluate the efficacy of flazasulfuron applied alone or in mixtures for providing control of herbaceous weeds. All sites were newly established loblolly pine (Pinus taeda L.) plantations. Plots were evaluated monthly until 180 days after treatment. No phytotoxicity on pine...

  20. Test of two methods for determining herbaceous yield and botanical ...

    African Journals Online (AJOL)

    Above-ground herbaceous yield was estimated using the comparative yield method to win + 10% (p < 0,05) of the harvested mean using 150 harvested and 600 rated quadrats of 50 x 50 cm. The number of quadrats can be substantially reduced by improved observer rating. Using the dry mass rank method and 240 ...

  1. The influence of tree thinning on the establishment of herbaceous ...

    African Journals Online (AJOL)

    The influence of tree thinning on the establishment of herbaceous plants in a semi-arid savanna of southern Africa. GN Smit, FG Rethman. Abstract. The investigation was conducted on an area covered by a dense stand of Colophospermum mopane. Seven plots (65 m × 180 m) were subjected to different intensities of tree ...

  2. Recreational transformation of the herbaceous layer in an urban forest ecosystem of Central Podolia

    Directory of Open Access Journals (Sweden)

    O. I. Blinkova

    2017-05-01

    Full Text Available This article examines the impact of recreational activities on herbaceous cover of forests on the example of an urban environment in Central Podolia. The features of changes in environmental conditions of ecotypes of an urban forest have been shown through the systematic, biomorphological and ecomorphic structure of the herbaceous cover, the ratio of ecological groups, changes in type of ecological strategy of species, assessment of ecological fractions valences, and phytodiversity. We found 78 species of vascular plants. The most diverse families are Asteraceae, Poaceae and Lamiaceae. The biomorphological range of phytodiversity of the intensive recreational zone is characterized by a high proportion of adventive and ruderal species, dominance of vegetative mobile species, forming of monodominant groups and disturbed distribution of all spectrum types for coenotic morphs. Perennial hemicryptophytes dominate in the spectrum of life forms. The share of therophytes increased along the gradient of recreational transformation. Unrosellate herbal plants dominate in the structure of aboveground shoots and leaf placement, plants that don’t have special modifications dominate in the structures of underground shoots. Helophytes dominated in the analysis of heliomorphic plants. Mesophytes dominated almost everywhere. The share of hydrocontrastophobes increased with a gradual removal from places of recreation. Changes in acidomorphic and nitromorphic structures of plants were not found. Types of transitional groups of ecological strategies, including CR-, CS-, and CRS-strategies prevailed. The share of patiens diminished. Exsplerents from all types of primary ecological strategies dominated. Analysis of ecological valence fractions showed that species of hemi-euryvalent and euryvalent fractions dominate among hydromorphs, hemi-euryvalent species dominate among ecogroups of scale variability humidification of soil, hemystenovalences species dominate among

  3. Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests

    Science.gov (United States)

    Hagar, J.C.; Dugger, K.M.; Starkey, E.E.

    2007-01-01

    Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

  4. A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Jones, M.H.

    1999-11-24

    To perform a statistically rigorous meta-analysis of research results on the response by herbaceous vegetation to increased atmospheric CO{sub 2} levels, a multiparameter database of responses was compiled from the published literature. Seventy-eight independent CO{sub 2}-enrichment studies, covering 53 species and 26 response parameters, reported mean response, sample size, and variance of the response (either as standard deviation or standard error). An additional 43 studies, covering 25 species and 6 response parameters, did not report variances. This numeric data package accompanies the Carbon Dioxide Information Analysis Center's (CDIAC's) NDP-072, which provides similar information for woody vegetation. This numeric data package contains a 30-field data set of CO{sub 2}-exposure experiment responses by herbaceous plants (as both a flat ASCII file and a spreadsheet file), files listing the references to the CO{sub 2}-exposure experiments and specific comments relevant to the data in the data sets, and this documentation file (which includes SAS{reg_sign} and Fortran codes to read the ASCII data file). The data files and this documentation are available without charge on a variety of media and via the Internet from CDIAC.

  5. Mechanisms for success after long-term nutrient enrichment in a boreal forest understory.

    Directory of Open Access Journals (Sweden)

    Tess Nahanni Grainger

    Full Text Available Global levels of reactive nitrogen are predicted to rise in the coming decades as a result of increased deposition from the burning of fossil fuels and the large-scale conversion of nitrogen into a useable form for agriculture. Many plant communities respond strongly to increases in soil nitrogen, particularly in northern ecosystems where nitrogen levels are naturally very low. An experiment in northern Canada that was initiated in 1990 has been investigating the effects of long-term nutrient enrichment (fertilizer added annually on a boreal forest understory community. We used this experiment to investigate why some species increase in abundance under nutrient enrichment whereas others decline. We focused on four species that differed in their responses to fertilization: Mertensia paniculata and Epilobium angustifolium increased in abundance, Achillea millefolium remained relatively constant and Festuca altaica declined. We hypothesized that the two species that were successful in the new high-nutrient, light-limited environment would be taller, have higher specific leaf area, change phenology by growing earlier in the season and be more morphologically plastic than their less successful counterparts. We compared plant height, specific leaf area, growth spurt date and allocation to leaves in plants grown in control and fertilized plots. We demonstrated that each of the two species that came to dominate fertilized plots has a different combination of traits and responses that likely gave them a competitive advantage; M. paniculata has the highest specific leaf area of the four species whereas E. angustifolium is tallest and exhibits morphological plasticity when fertilized by increasing biomass allocation to leaves. These results indicate that rather than one strategy determining success when nutrients become available, a variety of traits and responses may contribute to a species' ability to persist in a nutrient-enriched boreal forest

  6. Herbaceous Legume Encroachment Reduces Grass Productivity and Density in Arid Rangelands.

    Directory of Open Access Journals (Sweden)

    Thomas C Wagner

    Full Text Available Worldwide savannas and arid grasslands are mainly used for livestock grazing, providing livelihood to over a billion people. While normally dominated by perennial C4 grasses, these rangelands are increasingly affected by the massive spread of native, mainly woody legumes. The consequences are often a repression of grass cover and productivity, leading to a reduced carrying capacity. While such encroachment by woody plants has been extensively researched, studies on similar processes involving herbaceous species are rare. We studied the impact of a sustained and massive spread of the native herbaceous legume Crotalaria podocarpa in Namibia's escarpment region on the locally dominant fodder grasses Stipagrostis ciliata and Stipagrostis uniplumis. We measured tussock densities, biomass production of individual tussocks and tussock dormancy state of Stipagrostis on ten 10 m x 10 m plots affected and ten similarly-sized plots unaffected by C. podocarpa over eight consecutive years and under different seasonal rainfalls and estimated the potential relative productivity of the land. We found the percentage of active Stipagrostis tussocks and the biomass production of individual tussocks to increase asymptotically with higher seasonal rainfall reaching a maximum around 300 mm while the land's relative productivity under average local rainfall conditions reached only 40% of its potential. Crotalaria podocarpa encroachment had no effect on the proportion of productive grass tussocks, but reduced he productivity of individual Stipagrostis tussocks by a third. This effect of C. podocarpa on grass productivity was immediate and direct and was not compensated for by above-average rainfall. Besides this immediate effect, over time, the density of grass tussocks declined by more than 50% in areas encroached by C. podocarpa further and lastingly reducing the lands carrying capacity. The effects of C. podocarpa on grass productivity hereby resemble those of woody

  7. The environment, not space, dominantly structures the landscape patterns of the richness and composition of the tropical understory vegetation.

    Directory of Open Access Journals (Sweden)

    Yue-Hua Hu

    Full Text Available The mechanisms driving the spatial patterns of species richness and composition are essential to the understanding of biodiversity. Numerous studies separately identify the contributions of the environment (niche process and space (neutral process to the species richness or composition at different scales, but few studies have investigated the contributions of both types of processes in the two types of data at the landscape scale. In this study, we partitioned the spatial variations in all, exotic and native understory plant species richness and composition constrained by environmental variables and space in 134 plots that were spread across 10 counties in Hainan Island in southern China. The 134 plots included 70 rubber (Hevea brasiliensis plantation plots, 50 eucalyptus (Eucalyptus urophylla plantation plots, and 14 secondary forest plots. RDA based variation partitioning was run to assess the contribution of environment and space to species richness and composition. The results showed that the environmental variables alone explained a large proportion of the variations in both the species richness and composition of all, native, and exotic species. The RDA results indicated that overstory composition (forest type here plays a leading role in determining species richness and composition patterns. The alpha and beta diversities of the secondary forest plots were markedly higher than that of the two plantations. In conclusion, niche differentiation processes are the principal mechanisms that shape the alpha and beta diversities of understory plant species in Hainan Island.

  8. Mechanisms of herbaceous vegetation restoration successions

    Science.gov (United States)

    Pankratova, Lubov

    2017-04-01

    The vegetation dynamics study is an important sector of research in phytocenology. The changing vegetation mechanisms' studying with the purpose of forecasting and management processes is an urgent theoretical and practical task. We consider succession as successive series of composition changes and phytocenoses structure caused by internal reasons and external ones. In this case, we are dealing with natural, secondary and progressive successions. The rapid sequential change of associations aimed at restoring coenotic environment and not resulting in ecogenesis stage changes is called demattia. Fully restored coenotic environment corresponds to vegetation sublimation. The way to this most stable state goes via a number of derived associations, each of them can be seen as long phytocenotic sustainable phenomenon, but different in time. The ability of living beings to reproduce in one way or another, their spreading, filling the space and confrontation to adverse conditions presents an important preservation mechanism and biodiversity increase, as well as its sustainability. The bio-diversity indicator is very significant for stability maintainment and phytocenosis estimation. Succession mechanisms classification provides three categories of relationships between organisms in the successional series: model relief or stimulation corresponds to the phase of endoecological succession which means that early settlers in their activities change the environment, making it available for the next wave of colonists. The model of tolerance manifests itself in the form of competitive relationships, resulting in selection of more competitive species with a pronounced feature S. According to the inhibition model, all types of community are able to colonize open spaces, they are resistant to competitors invasion, but the later species are able to inhabit and increase their number only after the loss of any of the predecessors. The predecessors change environment settings making it

  9. Trophic flexibility and the persistence of understory birds in intensively logged rainforest.

    Science.gov (United States)

    Edwards, David P; Woodcock, Paul; Newton, Rob J; Edwards, Felicity A; Andrews, David J R; Docherty, Teegan D S; Mitchell, Simon L; Ota, Takahiro; Benedick, Suzan; Bottrell, Simon H; Hamer, Keith C

    2013-10-01

    Effects of logging on species composition in tropical rainforests are well known but may fail to reveal key changes in species interactions. We used nitrogen stable-isotope analysis of 73 species of understory birds to quantify trophic responses to repeated intensive logging of rainforest in northern Borneo and to test 4 hypotheses: logging has significant effects on trophic positions and trophic-niche widths of species, and the persistence of species in degraded forest is related to their trophic positions and trophic-niche widths in primary forest. Species fed from higher up the food chain and had narrower trophic-niche widths in degraded forest. Species with narrow trophic-niche widths in primary forest were less likely to persist after logging, a result that indicates a higher vulnerability of dietary specialists to local extinction following habitat disturbance. Persistence of species in degraded forest was not related to a species' trophic position. These results indicate changes in trophic organization that were not apparent from changes in species composition and highlight the importance of focusing on trophic flexibility over the prevailing emphasis on membership of static feeding guilds. Our results thus support the notion that alterations to trophic organization and interactions within tropical forests may be a pervasive and functionally important hidden effect of forest degradation. © 2013 Society for Conservation Biology.

  10. Driving Factors of Understory Evapotranspiration within a Siberian Larch Forest

    Science.gov (United States)

    Tobio, A.; Loranty, M. M.; Kropp, H.; Pena, H., III; Alexander, H. D.; Natali, S.; Kholodov, A. L.; Spawn, S.; Farmer, S.

    2017-12-01

    Amplified rates of climate change are causing alterations in vegetation productivity, hydrologic cycling, and wildfire severity and intensity in arctic ecosystems. Boreal larch forests in northeastern Siberia are a critical but understudied ecosystem that are affected by these modifications. These forests cover 2.5 million km2 with densities ranging from spare to thick. The current average canopy cover is at around 17% and is expected to increase with the observed increases in vegetation productivity and wildfire. These projected changes in forest density can alter the proportional contributions of over- and understory vegetation to whole ecosystem evapotranspiration. Low density boreal forests have much higher rates of understory evapotranspiration and can contribute as much as 80% to total ecosystem evapotranspiration, while the understory in high density forests is responsible for only around 15% of total ecosystem evapotranspiration. The objective of this research is to understand why there are changes in understory evapotranspiration with varying overstory density by looking at light levels, biomass, vegetation, and air and soil differences. To better learn about these differences in understory evapotranspiration in boreal larch forests the driving factors of evapotranspiration were measured within a burn scar with varying densities of high, medium, and low. Water fluxes were conducted using the static chamber technique under different environmental conditions. Furthermore, controlling factors of evapotranspiration such as photosynethically active radiation, vapor pressure deficit, soil moisture, moss cover, biomass, and leaf area index were measured or derived. In general, we found that low density areas have highest rates of evapotranspiration due to larger amount of biomass, and increased access to light, despite low levels of soil moisture. These results can help us understand how and why total ecosystem water exchange will change in boreal larch forests

  11. Double-Crested Cormorant ( Phalacrocorax auritus) Nesting Effects on Understory Composition and Diversity on Island Ecosystems in Lake Erie

    Science.gov (United States)

    McGrath, Darby M.; Murphy, Stephen D.

    2012-08-01

    The context for this study is the management concerns over the severity and extent of the impact of cormorants on island flora in the recent past on Lake Erie islands. Accordingly, this study sought to quantify the nesting colonies' influence on coarse woody litter and how nest densities and litter depth may influence the herbaceous layer, the seed bank composition and viability across the extent of three Lake Erie islands. The data for this study were collected from 2004 to 2008 on East Sister Island and Middle Island using two main strategies. First, herbaceous layer surveys, cormorant nest counts, soil seed bank cores, and litter depth measurements were executed using a plotless-point quarter method to test island-wide impacts from nesting activities (data were also collected on a third island, West Sister Island as a reference for the other two islands). Secondly, a sub-sample of the entire plot set was examined in particularly high nesting density areas for two islands (Middle Island and East Sister Island). Kruskal-Wallis tests indicated that there are subtle changes in the herbaceous diversity (total, native and exotic) and seed bank composition across the islands. The sub sample set of the plots demonstrated that Phalacrocorax auritus nest density does influence litter depth, herbaceous species abundance and diversity. Cormorant nesting pressures are restricted to areas of high nesting pressures and competition. However, there remains a risk to the interior herbaceous layer of the island if the effects of nesting pressures at the edges advance inward from this perimeter.

  12. Restoring Native Forest Understory: The Influence of Ferns and Light in a Hawaiian Experiment

    Directory of Open Access Journals (Sweden)

    Robert Shallenberger

    2013-03-01

    Full Text Available Ecological restoration is an increasingly important component of sustainable land management. We explore potential facilitative relationships for enhancing the cost-effectiveness of restoring native forest understory, focusing on two factors: (1 overstory shade and (2 possible facilitation by a fern (Dryopteris wallichiana, one of few native colonists of pasture in our montane Hawaiˈi study system. We planted 720 understory tree seedlings and over 4000 seeds of six species under six planting treatments: a full factorial combination of low, medium and high light, situating plantings in either the presence or absence of a mature fern. After three years, 75% of outplanted seedlings survived. Seedling survivorship was significantly higher in the presence of a fern (79% vs. 71% without a fern and in medium and low light conditions (81% vs. 64% in high light. Relative height was highest at low to medium light levels. After 2.2 years, 2.8% of the planted seeds germinated. We observed no significant differences in seed germination relative to light level or fern presence. Analyzing several approaches, we found nursery germination of seeds followed by outplanting ca. 20% less costly than direct seeding in the field. This study opens new questions about facilitation mechanisms that have the potential to increase the extent and effectiveness of restoration efforts.

  13. Spatial Heterogeneity of the Forest Canopy Scales with the Heterogeneity of an Understory Shrub Based on Fractal Analysis

    Directory of Open Access Journals (Sweden)

    Catherine K. Denny

    2017-04-01

    Full Text Available Spatial heterogeneity of vegetation is an important landscape characteristic, but is difficult to assess due to scale-dependence. Here we examine how spatial patterns in the forest canopy affect those of understory plants, using the shrub Canada buffaloberry (Shepherdia canadensis (L. Nutt. as a focal species. Evergreen and deciduous forest canopy and buffaloberry shrub presence were measured with line-intercept sampling along ten 2-km transects in the Rocky Mountain foothills of west-central Alberta, Canada. Relationships between overstory canopy and understory buffaloberry presence were assessed for scales ranging from 2 m to 502 m. Fractal dimensions of both canopy and buffaloberry were estimated and then related using box-counting methods to evaluate spatial heterogeneity based on patch distribution and abundance. Effects of canopy presence on buffaloberry were scale-dependent, with shrub presence negatively related to evergreen canopy cover and positively related to deciduous cover. The effect of evergreen canopy was significant at a local scale between 2 m and 42 m, while that of deciduous canopy was significant at a meso-scale between 150 m and 358 m. Fractal analysis indicated that buffaloberry heterogeneity positively scaled with evergreen canopy heterogeneity, but was unrelated to that of deciduous canopy. This study demonstrates that evergreen canopy cover is a determinant of buffaloberry heterogeneity, highlighting the importance of spatial scale and canopy composition in understanding canopy-understory relationships.

  14. The effect of technogenic emissions on the heavy metals accumulation by herbaceous plants.

    Science.gov (United States)

    Chaplygin, Victor; Minkina, Tatiana; Mandzhieva, Saglara; Burachevskaya, Marina; Sushkova, Svetlana; Poluektov, Evgeniy; Antonenko, Elena; Kumacheva, Valentina

    2018-02-07

    The effect of technogenic emissions on the input of Pb, Zn, Cd, Cu, Mn, Cr, and Ni into plants from the Poaceae and Asteraceae families has been studied. Soil and plant contamination by anthropogenic emissions from industrial enterprises leads the decreasing of crop quality; therefore, the monitoring investigation of plants and soils acquires special importance. The herbaceous plants may be used as bioindicators for main environmental changes. It was found that the high level of anthropogenic load related to atmospheric emissions from the power plant favors the heavy metal (HM) accumulation in herbaceous plants. Contamination with Pb, Cd, Cr, and Ni was revealed in plants growing near the power plant. Heavy metals arrive to plants from the soil in the form of mobile compounds. Plant family is one of the main factors affecting the HM distribution in the above- and underground parts of plants. Plants from the Poaceae family accumulate less chemical elements in their aboveground parts than the Asteraceae plants. Ambrosia artemisiifolia and Artemisia austriaca are HM accumulators. For assessing the stability of plants under contamination with HMs, metal accumulation by plants from soil (the bioconcentration factor) and metal phytoavailability from plants above- and underground parts (the acropetal coefficient) were calculated. According to the bioconcentration factor and translocation factor values, Poaceae species are most resistant to technogenic contamination with HMs. The translocation factor highest values were found for Tanacetum vulgare; the lowest bioconcentration factor values were typical for Poa pratensis.

  15. Land-Use History and Contemporary Management Inform an Ecological Reference Model for Longleaf Pine Woodland Understory Plant Communities.

    Energy Technology Data Exchange (ETDEWEB)

    Brudvig, Lars A. [Department of Plant Biology, Michigan State University; Orrock, John L. [Department of Zoology, University of Wisconsin; Damschen, Ellen I. [Department of Zoology, University of Wisconsin; et al, et al

    2014-01-23

    Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plain based on relationships between understory plant community composition, soils lol(which broadly structure these communities), and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together. and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients–i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes). Our study demonstrates the utility

  16. Land-Use History and Contemporary Management Inform an Ecological Reference Model for Longleaf Pine Woodland Understory Plant Communities

    Science.gov (United States)

    Brudvig, Lars A.; Orrock, John L.; Damschen, Ellen I.; Collins, Cathy D.; Hahn, Philip G.; Mattingly, W. Brett; Veldman, Joseph W.; Walker, Joan L.

    2014-01-01

    Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plain based on relationships between understory plant community composition, soils (which broadly structure these communities), and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients–i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes). Our study demonstrates the utility of

  17. Land-use history and contemporary management inform an ecological reference model for longleaf pine woodland understory plant communities.

    Directory of Open Access Journals (Sweden)

    Lars A Brudvig

    Full Text Available Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plain based on relationships between understory plant community composition, soils (which broadly structure these communities, and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients-i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes. Our study demonstrates

  18. Targeted reforestation could reverse declines in connectivity for understory birds in a tropical habitat corridor.

    Science.gov (United States)

    Fagan, Matthew E; DeFries, Ruth S; Sesnie, Steven E; Arroyo-Mora, J Pablo; Chazdon, Robin L

    2016-07-01

    Re-establishing connectivity between protected areas isolated by habitat clearing is a key conservation goal in the humid tropics. In northeastern Costa Rica, payments for environmental services (PES) and a government ban on deforestation have subsidized forest protection and reforestation in the San Juan-La Selva Biological Corridor (SJLSBC), resulting in a decline in mature forest loss and the expansion of tree plantations. We use field studies and graph models to assess how conservation efforts have altered functional connectivity over the last 25 years for four species of insectivorous understory birds. Field playback studies assessed how reforestation habitat quality affected the willingness of Myrmeciza exsul, Henicorhina leucosticta, Thamnophilus atrinucha, and Glyphorynchus spirurus to travel outside forest habitat for territorial defense. Observed travel distances were greatest in nonnative and native tree plantations with high understory stem density, regardless of overstory composition. In contrast, tree plantations with low stem density had travel responses comparable to open pasture for three of the four bird species. We modeled landscape connectivity for each species using graph models based on varying possible travel distances in tree plantations, gallery forests, and pastures. From 1986 to 2011, connectivity for all species declined in the SJLSBC landscape (5825 km 2 ) by 14% to 21% despite only a 4.9% net loss in forest area and the rapid expansion of tree plantations over 2% of the landscape. Plantation placement in the landscape limited their potential facilitation of connectivity because they were located either far from forest cover or within already contiguous forest areas. We mapped current connectivity bottlenecks and identified priority areas for future reforestation. We estimate that reforestation of priority areas could improve connectivity by 2% with only a 1% gain in forest cover, an impressive gain given the small area reforested

  19. Structural and floristic changes caused by gamma radiation in understory vegetation of two forest types in northern Wisconsin

    International Nuclear Information System (INIS)

    Zavitkovski, J.

    1977-01-01

    Structural and floristic changes of the understory vegetation of gamma-irradiated aspen and maple-aspen-birch (MAB) communities in northern Wisconsin were quantified by comparing the pre- and postirradiation floristic composition and vegetational cover. A size-dependent radiosensitivity was determined among three vegetational strata, the tall shrubs being the most sensitive, low shrubs intermediate, and herbs the most resistant. Corylus cornuta, whose nuclear characteristics indicated that it could be resistant, was very sensitive and was completely eliminated at exposures of 500 r/20-hr day or higher. The cover of Rubus strigosus, minimal before irradiation, increased manifold and accounted for most of the shrub cover 2 years after the conclusion of irradiation. Among herbs, Carex pensylvanica and Luzula acuminata were very resistant, and Trillium grandiflorum, Aralia nudicaulis, Oryzopsis asperifolia, and Clintonia borealis were very sensitive. The herbaceous stratum of the aspen type appeared more resistant than that of the MAB. This difference apparently resulted from differences in floristic composition of the two communities

  20. Spatial partitioning of water use by herbaceous and woody lifeforms in semiarid woodlands

    International Nuclear Information System (INIS)

    Breshears, D.D.

    1993-01-01

    Ecological studies of soil moisture, plant water uptake, and community composition in semiarid regions have focused on differences with depth in the soil profile, yet there are many reasons to expect that moisture also varies with the presence or absence of woody vegetation. Plant and soil moisture relationships for three dominant species in a semiarid woodland, Bouteloua gracilis, Juniperus monosperma, and Pinus edulis, were studied for 1.5 years. Soil moisture varied by type of plant cover as well as by depth. Plant water potential and conductance differed among species and was related to spatial variability in soil moisture. Water potential for blue grama was most correlated with soil moisture in the 0-15 cm layer of intercanopies; juniper water potential was highly correlated with soil moisture in the 0-15 cm layer beneath tree canopies of either species, and pinyon water potential was only weakly correlated with soil moisture in the 15-30 cm depth interval beneath pinyons. Pinyons had consistently greater maximum conductance rates than junipers, even though pinyon conductance was more sensitive to reductions in soil moisture. The results from this study indicate that horizontal differences in the soil moisture profile associated with type of plant cover may be as important as differences in depth for predicting plant-water relationships. A simple model was hypothesized for predicting community composition of three lifeforms: Herbaceous plants, shallow-rooted woody plants, and deeper-rooted woody plants. Distributions of roots of each lifeform and plant-available water were defined with respect to four soil compartments that distinguish upper vs. lower and canopy vs. intercanopy soil regions. The model predicts that multiple combinations of herbaceous and woody biomass can exist at a site and was qualitatively consistent with field data from a climatic gradient

  1. Productivity and cost of conventional understory biomass harvesting systems

    Science.gov (United States)

    Douglas E. Miller; Thomas J. Straka; Bryce J. Stokes; William Watson

    1987-01-01

    Conventional harvesting equipment was tested for removing forest understory biomass (energywood) for use as fuel. Two types of systems were tested--a one-pass system and a two-pass system. In the one-pass system, the energywood and pulpwood were harvested simultaneously. In the two-pass system, the energywood was harvested in a first pass through the stand, and the...

  2. Floristic conservation value, nested understory floras, and the development of second-growth forest.

    Science.gov (United States)

    Spyreas, Greg; Matthews, Jeffrey W

    2006-08-01

    Nestedness analysis can reveal patterns of plant composition and diversity among forest patches. For nested floral assemblages, the plants occupying any one patch are a nested subset of the plants present in successively more speciose patches. Elimination of sensitive understory plants with human disturbance is one of several mechanisms hypothesized to generate nonrandom, nested floral distributions. Hypotheses explaining distributions of understory plants remain unsubstantiated across broad landscapes of varying forest types and disturbance histories. We sampled the vegetation of 51 floodplain and 55 upland forests across Illinois (USA) to examine how the diversity, composition, and nestedness of understory floras related to their overstory growth and structure (basal area), and their overall floristic conservation value (mean C). We found that plant assemblages were nested with respect to site species richness, such that rare plants indicated diverse forests. Floras were also nested with respect to site mean C and basal area (BA). However, in an opposite pattern from what we had expected, floras of high-BA stands were nested subsets of those of low-BA stands. A set of early-successional plants restricted to low-BA stands, and more importantly, the absence of a set of true forest plants in high-BA stands, accounted for this pattern. Additionally, we observed a decrease in species richness with increasing BA. These results are consistent with the hypothesis that recovery of true forest plants does not occur concurrently with overstory regeneration following massive anthropogenic disturbance. Nestedness by site mean C indicates that high conservation value (conservative) plants co-occur in highly diverse stands; these forests are assumed to be less disturbed historically. Because site mean C was uncorrelated with BA, BA-neutral disturbances such as livestock usage are suggested as accounting for between-site differences in mean C. When considered individually

  3. Evaluation of nodulation and nitrogen fixing potentials of some herbaceous legumes in inland valley soil

    International Nuclear Information System (INIS)

    Bayorbor, T. B.; Addai, I. K.; Lawson, I. Y. D.; Dogbe, W.; Djagbletey, D.

    2006-01-01

    A screening experiment was conducted to evaluate the nodulation, nitrogen fixation and biomass production of eleven herbaceous legumes in three soil series mainly used for rice production in the Guinea savannah agro-ecological zone of Ghana. This study was carried out with a view to fully exploiting the potential of N-fixating legumes as a supplement to inorganic N-fertilizers in rice-based cropping systems. The treatment combinations were laid out in a factorial experiment in randomized complete block design (RCBD) with three replications. Plant samples were harvested at flowering for nodule count, biomass production and N-fixation. The study revealed that the mucuna and crotalaria species were the best nitrogen fixers and biomass producers. For increased yields of rice in the study area, these legumes require more intensive field study for their integration into the rice-based cropping systems. (au)

  4. Mapping Canopy Damage from Understory Fires in Amazon Forests Using Annual Time Series of Landsat and MODIS Data

    Science.gov (United States)

    Morton, Douglas C.; DeFries, Ruth S.; Nagol, Jyoteshwar; Souza, Carlos M., Jr.; Kasischke, Eric S.; Hurtt, George C.; Dubayah, Ralph

    2011-01-01

    Understory fires in Amazon forests alter forest structure, species composition, and the likelihood of future disturbance. The annual extent of fire-damaged forest in Amazonia remains uncertain due to difficulties in separating burning from other types of forest damage in satellite data. We developed a new approach, the Burn Damage and Recovery (BDR) algorithm, to identify fire-related canopy damages using spatial and spectral information from multi-year time series of satellite data. The BDR approach identifies understory fires in intact and logged Amazon forests based on the reduction and recovery of live canopy cover in the years following fire damages and the size and shape of individual understory burn scars. The BDR algorithm was applied to time series of Landsat (1997-2004) and MODIS (2000-2005) data covering one Landsat scene (path/row 226/068) in southern Amazonia and the results were compared to field observations, image-derived burn scars, and independent data on selective logging and deforestation. Landsat resolution was essential for detection of burn scars less than 50 ha, yet these small burns contributed only 12% of all burned forest detected during 1997-2002. MODIS data were suitable for mapping medium (50-500 ha) and large (greater than 500 ha) burn scars that accounted for the majority of all fire-damaged forest in this study. Therefore, moderate resolution satellite data may be suitable to provide estimates of the extent of fire-damaged Amazon forest at a regional scale. In the study region, Landsat-based understory fire damages in 1999 (1508 square kilometers) were an order of magnitude higher than during the 1997-1998 El Nino event (124 square kilometers and 39 square kilometers, respectively), suggesting a different link between climate and understory fires than previously reported for other Amazon regions. The results in this study illustrate the potential to address critical questions concerning climate and fire risk in Amazon forests by

  5. On the global relationships between photosynthetic water-use efficiency, leaf mass per unit area and atmospheric demand in woody and herbaceous plants

    Science.gov (United States)

    Letts, M. G.; Fox, T. A.; Gulias, J.; Galmes, J.; Hikosaka, K.; Wright, I.; Flexas, J.; Awada, T.; Rodriguez-Calcerrada, J.; Tobita, H.

    2013-12-01

    A global dataset was compiled including woody and herbaceous C3 species from forest, Mediterranean and grassland-shrubland ecosystems, to elucidate the dependency of photosynthetic water-use efficiency on vapour pressure deficit (D) and leaf traits. Mean leaf mass per unit area (LMA) was lower and mass-based leaf nitrogen content (Nmass) was higher in herbaceous species. Higher mean stomatal conductance (gs), transpiration rate (E) and net CO2 assimilation rate under light saturating conditions (Amax) were observed in herbs, but photosynthetic and intrinsic water-use efficiencies (WUE = Amax/E and WUEi = Amax/gs) were lower than in woody plants. Woody species maintained stricter stomatal regulation of water loss at low D, resulting in a steeper positive and linear relationship between log D and log E. Herbaceous species possessed very high gs at low D, resulting in higher ratio of substomatal to atmospheric CO2 concentrations (ci/ca) and E, but lower WUE and WUEi than woody plants, despite higher Amax. The lower WUE and higher rates of gas exchange were most pronounced in herbs with low LMA and high Nmass. Photosynthetic water use also differed between species from grassland-shrubland and Mediterranean or forest environments. Water-use efficiency showed no relationship with either D or LMA in grassland-shrubland species, but showed a negative relationship with D in forest and chaparral. The distinct photosynthetic water-use of woody and herbaceous plants is consistent with the opportunistic growth strategy of herbs and the more conservative growth strategy of woody species. Further research is recommended to examine the implications of these functional group and ecosystem differences in the contexts of climate and atmospheric change.

  6. Decomposition of aboveground biomass of a herbaceous wetland stand

    OpenAIRE

    KLIMOVIČOVÁ, Lucie

    2010-01-01

    The master?s thesis is part of the project GA ČR č. P504/11/1151- Role of plants in the greenhouse gas budget of a sedge fen. This thesis deals with the decomposition of aboveground vegetation in a herbaceous wetland. The decomposition rate was established on the flooded part of the Wet Meadows near Třeboň. The rate of the decomposition processes was evaluated using the litter-bag method. Mesh bags filled with dry plant matter were located in the vicinity of the automatic meteorological stati...

  7. Evaluation of the Relative Merits of Herbaceous and Woody Crops for Use in Tunable Thermochemical Processing

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joon-Hyun [Ceres, Inc., Thousand Oaks, CA (United States); Martinalbo, Ilya [Choren USA, LLC, Houston, TX (United States)

    2011-12-01

    This report summarizes the work and findings of the grant work conducted from January 2009 until September 2011 under the collaboration between Ceres, Inc. and Choren USA, LLC. This DOE-funded project involves a head-to-head comparison of two types of dedicated energy crops in the context of a commercial gasification conversion process. The main goal of the project was to gain a better understanding of the differences in feedstock composition between herbaceous and woody species, and how these differences may impact a commercial gasification process. In this work, switchgrass was employed as a model herbaceous energy crop, and willow as a model short-rotation woody crop. Both crops are species native to the U.S. with significant potential to contribute to U.S. goals for renewable liquid fuel production, as outlined in the DOE Billion Ton Update (http://www1.eere.energy.gov/biomass/billion_ton_update.html, 2011). In some areas of the U.S., switching between woody and herbaceous feedstocks or blending of the two may be necessary to keep a large-scale gasifier operating near capacity year round. Based on laboratory tests and process simulations it has been successfully shown that suitable high yielding switchgrass and willow varieties exist that meet the feedstock specifications for large scale entrained flow biomass gasification. This data provides the foundation for better understanding how to use both materials in thermochemical processes. It has been shown that both switchgrass and willow varieties have comparable ranges of higher heating value, BTU content and indistinguishable hydrogen/carbon ratios. Benefits of switchgrass, and other herbaceous feedstocks, include its low moisture content, which reduce energy inputs and costs for drying feedstock. Compared to the typical feedstock currently being used in the Carbo-V® process, switchgrass has a higher ash content, combined with a lower ash melting temperature. Whether or not this may cause inefficiencies in the

  8. Analysis of herbaceous vegetation diversity in a reservoir in the Brazilian semiarid region (Açude Itans – RN

    Directory of Open Access Journals (Sweden)

    Diógenes Félix da Silva Costa

    2016-02-01

    Full Text Available Herbaceous plants represent a significant portion of the biodiversity in the Caatinga and are also found around artificial reservoirs in different habitats. This work studied the diversity and the spatial distribution of herbaceous vegetation in the flood zone of Açude Itans, a reservoir located in Caicó (which has a semiarid climate in the state of Rio Grande do Norte. Using the spatial analysis results, the statistical data were stored and analyzed in a geographic information system (GIS and a series of thematic maps of the study area were generated. Nine points were sampled in the water/soil ecotone of the reservoir and 142 specimens were collected. Forty-four species were identified and there was a strong presence of weeds and/or ruderal species. The most significant family was Poaceae, with 37 individuals and seven species, followed by Fabaceae, with 31 individuals and ten species. Cucurbitaceae, Plantaginaceae and Portulacaceae were the least representative families. The least diverse sampling site was the transition zone upstream of the reservoir, while the area near the dam was the most diverse.

  9. Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China

    Science.gov (United States)

    Tian, Di; Li, Peng; Fang, Wenjing; Xu, Jun; Luo, Yongkai; Yan, Zhengbing; Zhu, Biao; Wang, Jingjing; Xu, Xiaoniu; Fang, Jingyun

    2017-07-01

    Reactive nitrogen (N) increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m × 20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings), and ground-cover plants (ferns) according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height) of 5-10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha-1 yr-1) and N100 fertilized plots (100 kg N ha-1 yr-1), while the growth of median and large trees with a DBH of > 10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical forest, and that the limitation of other nutrients in the forest

  10. Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China

    Directory of Open Access Journals (Sweden)

    D. Tian

    2017-07-01

    Full Text Available Reactive nitrogen (N increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m  ×  20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings, and ground-cover plants (ferns according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height of 5–10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha−1 yr−1 and N100 fertilized plots (100 kg N ha−1 yr−1, while the growth of median and large trees with a DBH of  >  10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical

  11. Variability in understory evapotranspiration with overstory density in Siberian larch forests

    Science.gov (United States)

    Tobio, A.; Loranty, M. M.; Kropp, H.; Pena, H., III; Alexander, H. D.; Natali, S.; Kholodov, A. L.

    2016-12-01

    Arctic ecosystems are changing rapidly in response to amplified rates of climate change. Increased vegetation productivity, altered ecosystem carbon and hydrologic cycling, and increased wildfire severity are among the key responses to changing permafrost and climate conditions. Boreal larch forests in northeastern Siberia are a critical but understudied ecosystem affected by these modifications. Understory vegetation in these ecosystems, which typically have low canopy cover, may account for half of all water fluxes. Despite the potential importance of the understory for ecosystem water exchange, there has been relatively little research examining variability in understory evapotranspiration in boreal larch forests. In particular, the water balance of understory shrubs and mosses is largely undefined and could provide insight on how understory vegetation and our changing climate interact. This is especially important because both observed increases in vegetation productivity and wildfire severity could lead to increases in forests density, altering the proportional contributions of over- and understory vegetation to whole ecosystem evapotranspiration. In order to better understand variability in understory evapotranspiration we measured in larch forests with differing overstory density and permafrost conditions that likely vary as a consequence of fire severity. We used the static chamber technique to measure fluxes across a range of understory vegetation types and environmental conditions. In general, we found that the understory vegetation in low density stands transpires more than that in high density stands. This tends to be correlated with a larger amount of aboveground biomass in the low density stands, and an increase in solar radiation, due to less shading by overstory trees. These results will help us to better understand water balances, evapotranspiration variability, and productivity changes associated with climate on understory vegetation. Additionally

  12. Genetic Improvement of Switchgrass and Other Herbaceous Plants for Use as Biomass Fuel Feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, K.P.

    2001-01-11

    It should be highly feasible to genetically modify the feedstock quality of switchgrass and other herbaceous plants using both conventional and molecular breeding techniques. Effectiveness of breeding to modify herbages of switchgrass and other perennial and annual herbaceous species has already been demonstrated. The use of molecular markers and transformation technology will greatly enhance the capability of breeders to modify the plant structure and cell walls of herbaceous plants. It will be necessary to monitor gene flow to remnant wild populations of plants and have strategies available to curtail gene flow if it becomes a potential problem. It also will be necessary to monitor plant survival and long-term productivity as affected by genetic changes that improve forage quality. Information on the conversion processes that will be used and the biomass characteristics that affect conversion efficiency and rate is absolutely essential as well as information on the relative economic value of specific traits. Because most forage or biomass quality characteristics are highly affected by plant maturity, it is suggested that plant material of specific maturity stages be used in research to determining desirable feedstock quality characteristics. Plant material could be collected at various stages of development from an array of environments and storage conditions that could be used in conversion research. The same plant material could be used to develop NIRS calibrations that could be used by breeders in their selection programs and also to develop criteria for a feedstock quality assessment program. Breeding for improved feedstock quality will likely affect the rate of improvement of biomass production per acre. If the same level of resources are used, multi-trait breeding simply reduces the selection pressure and hence the breeding progress that can be made for a single trait unless all the traits are highly correlated. Since desirable feedstock traits are likely

  13. Examination of the combustion conditions of herbaceous biomass

    Energy Technology Data Exchange (ETDEWEB)

    Szemmelveisz, K.; Szucs, I.; Palotas, A.B.; Winkler, L. [Department of Combustion Technology and Thermal Energy, University of Miskolc (Hungary); Eddings, E.G. [Department of Chemical Engineering, University of Utah, Salt Lake City (United States)

    2009-06-15

    Power generation from biomass is a fairly new area, and boilers that utilize various types of biomass have in many cases experienced serious problems with slagging, fouling and corrosion of boiler tubes. Mineral matter in these fuels can deposit on the heat-exchanger surfaces in the boiler and generate an insulating layer, which will significantly reduce the degree of heat-transfer from flue gas to water and steam. Our investigations were focused on the slag characteristics of different kinds of herbaceous biomass fuels. Since there is usually a reducing atmosphere present in the direct combustion zone of modern low-NO{sub x} firing systems, it is important to study mineral matter transformation of burned fuel residues in a reducing atmosphere. An excellent device for this type of study is the electric-resistance heated Bunte-Baum softening temperature testing instrument, which was used in this work. Ash chemical composition was analyzed via flame atomic absorption spectrometry and the microstructure of ash was determined using a scanning electron microscope. Crystalline compounds of the ashes were identified by using X-ray powder diffraction. This paper provides an overview of results on the combustion and slag characteristics of herbaceous biomass fuels. The results include chemical compositions, morphology and softening properties of these fuels, with special attention to switch grass and sunflower seed shell. (author)

  14. Expected international demand for woody and herbaceous feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Lamers, Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jacobson, Jacob [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mohammad, Roni [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wright, Christopher [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    The development of a U.S. bioenergy market and ultimately ‘bioeconomy’ has primarily been investigated with a national focus. Limited attention has been given to the potential impacts of international market developments. The goal of this project is to advance the current State of Technology of a single biorefinery to the global level providing quantitative estimates on how international markets may influence the domestic feedstock supply costs. The scope of the project is limited to feedstock that is currently available and new crops being developed to be used in a future U.S. bioeconomy including herbaceous residues (e.g., corn stover), woody biomass (e.g., pulpwood), and energy crops (e.g., switchgrass). The timeframe is set to the periods of 2022, 2030, and 2040 to align with current policy targets (e.g., the RFS2) and future updates of the Billion Ton data. This particular milestone delivers demand volumes for generic woody and herbaceous feedstocks for the main (net) importing regions along the above timeframes. The regional focus of the study is the European Union (EU), currently the largest demand region for U.S. pellets made from pulpwood and forest residues. The pellets are predominantly used in large-scale power plants (>5MWel) in the United Kingdom (UK), the Netherlands (NL), Belgium (BE), and Denmark (DK).

  15. Differences in Plant Traits among N-fixing Trees in Hawaii Affect Understory Nitrogen Cycling

    Science.gov (United States)

    August-Schmidt, E.; D'Antonio, C. M.

    2016-12-01

    Nitrogen (N) fixing trees are frequently used to restore soil functions to degraded ecosystems because they can increase soil organic matter and N availability. Although N-fixers are lumped into a single functional group, the quality and quantity of the plant material they produce and the rate at which they accrete and add N to the cycling pool likely vary. This talk will focus on the questions: (1) How does N-cycling differ among N-fixing tree species? And (2) Which plant traits are most important in distinguishing the soil N environment? To address these questions, we investigated planted stands of two Hawaiian native N-fixing trees (Acacia koa and Sophora chrysophylla) and `natural' stands of an invasive N-fixing tree (Morella faya) in burned seasonal submontane woodlands in Hawaii Volcanoes National Park. We measured the relative availability of nitrogen in the soil pool and understory plant community as well as characterizing the rate and amount of N cycling in these stands both in the field and using long term soil incubations in the laboratory. We found that N is cycled very differently under these three N-fixers and that this correlates with differences in their leaf traits. S. chrysophylla had the highest foliar %N and highest specific leaf area, and stands of these trees are associated with faster N-cycling, resulting in greater N availability compared to all other site types. Incubated S. chrysophylla soils mineralized almost twice as much N as any other soil type over the course of the experiment. The comparatively high-N environment under S. chrysophylla suggests that litter quality may be more important than litter quantity in determining nitrogen availability to the understory community.

  16. Understory vegetation data quality assessment for the Interior West Forest and Inventory Analysis program

    Science.gov (United States)

    Paul L. Patterson; Renee A. O' Brien

    2011-01-01

    The Interior West Forest Inventory and Analysis (IW-FIA) program of the USDA Forest Service collects field data on understory vegetation structure that have broad applications. In IW-FIA one aspect of quality assurance is assessed based on the repeatability of field measurements. The understory vegetation protocol consists of two suites of measurements; (1) the...

  17. Wood and understory production under a range of ponderosa pine stocking levels, Black Hills, South Dakota

    Science.gov (United States)

    Daniel W. Uresk; Carleton B. Edminster; Kieth E. Severson

    2000-01-01

    Stemwood and understory production (kg ha-1) were estimated during 3 nonconsecutive years on 5 growing stock levels of ponderosa pine including clearcuts and unthinned stands. Stemwood production was consistently greater at mid- and higher pine stocking levels, and understory production was greater in stands with less pine; however, there were no...

  18. Dwarf Mistletoe on Red Fir . . . infection and control in understory stands

    Science.gov (United States)

    Robert F. Scharpf

    1969-01-01

    Height and age of understory red fir (Abies magnifica A. Murr.) were related to dwarf mistletoe (Arceuthobiilm campylopodum f. abietinum) infection from the surrounding overstory red fir on four National Forests in California. Percentage of trees infected and intensity of infection increased significantly as height of understory...

  19. A model for estimating understory vegetation response to fertilization and precipitation in loblolly pine plantations

    Science.gov (United States)

    Curtis L. VanderSchaaf; Ryan W. McKnight; Thomas R. Fox; H. Lee Allen

    2010-01-01

    A model form is presented, where the model contains regressors selected for inclusion based on biological rationale, to predict how fertilization, precipitation amounts, and overstory stand density affect understory vegetation biomass. Due to time, economic, and logistic constraints, datasets of large sample sizes generally do not exist for understory vegetation. Thus...

  20. Selection and characterization of coal mine autochthonous rhizobia for the inoculation of herbaceous legumes.

    Science.gov (United States)

    Hernández, Anabel González; de Moura, Ginaini Doin; Binati, Renato Leal; Nascimento, Francisco Xavier Inês; Londoño, Diana Morales; Mamede, Ana Carolina Peixoto; da Silva, Emanuela Pille; de Armas, Rafael Dutra; Giachini, Admir José; Rossi, Márcio José; Soares, Cláudio Roberto Fonsêca Sousa

    2017-09-01

    Coal open pit mining in the South of Santa Catarina state (Brazil) was inappropriately developed, affecting approximately 6.700 ha. Re-vegetation is an alternative for the recovery of these areas. Furthermore, the use of herbaceous legumes inoculated with nitrogen fixing bacteria is motivated due to the difficulty implementing a vegetation cover in these areas, mainly due to low nutrient availability. Therefore, the aim of this work was to evaluate, among 16 autochthonous rhizobia isolated from the coal mining areas, those with the greatest potential to increase growth of the herbaceous legumes Vicia sativa and Calopogonium mucunoides. Tests were conducted in greenhouse containing 17 inoculation treatments (16 autochthonous rhizobia + Brazilian recommended strain for each plant species), plus two treatments without inoculation (with and without mineral nitrogen). After 60 days, nodulation, growth, N uptake, and symbiotic efficiency were evaluated. Isolates characterization was assessed by the production of indole acetic acid, ACC deaminase, siderophores, and inorganic phosphate solubilization. The classification of the isolates was performed by 16 S rDNA gene sequencing. Only isolates UFSC-M4 and UFSC-M8 were able to nodulate C. mucunoides. Among rhizobia capable of nodulating V. sativa, only UFSC-M8 was considered efficient. It was found the presence of more than one growth-promoting attributes in the same organism, and isolate UFSC-M8 presented all of them. Isolates were classified as belonging to Rhizobium, Burkholderia and Curtobacterium. The results suggest the inoculation of Vicia sativa with strain UFSC-M8, classified as Rhizobium sp., as a promising alternative for the revegetation of coal mining degraded areas.

  1. Spatial variation in the structure and composition of the herbaceous community in a semiarid region of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    KA. Silva

    Full Text Available In the arid and semiarid environments of the world, microhabitats serve as models for the structure of vegetation communities. The goal of this study was to identify differences in the structures of the herbaceous communities growing on a crystalline substrate and those growing on a sedimentary substrate in a semiarid region of northeastern Brazil. One hundred 1 × 1 m plots were established in each area for quantitative sampling, with 69 species recorded in the crystalline area and 76 in the sedimentary area. The average plant density was higher in the sedimentary area, and average diameters and heights were greater in the crystalline area. The families and species with a high Importance Value Index (IVI and a high Mixed Ecological Value Index (MEVI differed between the areas. Of the species with high densities, only four were found in both areas. Shannon-Weiner diversity index values in the crystalline (2.96 nats/ind.-1 and sedimentary (2.89 nats/ind.-1 areas were similar. Evenness values on both substrates were also similar (0.72 and 0.71 in the crystalline and sedimentary areas, respectively. This study shows that variations in plant establishment conditions between crystalline and sedimentary areas in a semiarid region of northeastern Brazil should be considered as structure-modeling factors for the herbaceous community.

  2. Eleventh-year results of fertilization, herbaceous, and woody plant control in a loblolly pine plantation

    Science.gov (United States)

    James D. Haywood; Allan E. Tiarks

    1990-01-01

    Through 11 years, fertilization at planting significantly increased the stemwood volume (outside bark) per loblolly pine (Pinus taeda L.) on an intensively prepared moderately well-drained fine sandy loam site in northern Louisiana. Four years of herbaceous plant control significantly increased pine survival, and because herbaceous plant control...

  3. Diet of Wilson's warblers and distribution of arthropod prey in the understory of Douglas-fir forests

    Science.gov (United States)

    Hagar, Joan C.; Dugger, Kate; Starkey, Edward E.

    2007-01-01

    Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

  4. Effects of thinning, burning, seeding, and slash arrangements on understory communities in pinyon-juniper woodlands of northern Arizona

    Directory of Open Access Journals (Sweden)

    Maria Irwin

    2011-11-01

    Full Text Available Pinyon-juniper woodlands are a dominant ecosystem in the American Southwest that have been increasing in density over the last century, generating concerns about the effects on wildlife habitat, livestock forage, and wildfire risk. We tested 16 treatment combinations designed to restore stands to historic conditions by examining the impact on understory plant richness and abundance. We thinned three sites comprised of different parent soil materials: limestone, sandstone, and basalt. Each site had one of four slash arrangements: piled, broadcast, clustered, or no thinning. Each of these arrangements received a different burning/seeding treatment: prescribed fire, seeding, prescribed fire and seeding, or none. This study corresponded with the driest period in the last 55 years, and plant species richness decreased by an average of 40% from the previous year in the control plots. Richness was significantly different due to slash arrangement at the basalt site only. Burning or seeding did not affect richness at any of the sites. Plant species abundance was generally low and not influenced by treatment or site. This study demonstrates that extensive ecosystem manipulation in the pinyon-juniper woodlands of northern Arizona did not affect understory richness or abundance the first year after treatment during a drought.

  5. Effects of thinning, burning, seeding, and slash arrangements on understory communities in pinyon-juniper woodlands of northern Arizona

    Directory of Open Access Journals (Sweden)

    Maria R. Irwin

    2011-06-01

    Full Text Available Pinyon-juniper woodlands are a dominant ecosystem in the American Southwest that have been increasing in density over the last century, generating concerns about the effects on wildlife habitat, livestock forage, and wildfire risk. We tested 16 treatment combinations designed to restore stands to historic conditions by examining the impact on understory plant richness and abundance. We thinned three sites comprised of different parent soil materials: limestone, sandstone, and basalt. Each site had one of four slash arrangements: piled, broadcast, clustered, or no thinning. Each of these arrangements received a different burning/seeding treatment: prescribed fire, seeding, prescribed fire and seeding, or none. This study corresponded with the driest period in the last 55 years, and plant species richness decreased by an average of 40% from the previous year in the control plots. Richness was significantly different due to slash arrangement at the basalt site only. Burning or seeding did not affect richness at any of the sites. Plant species abundance was generally low and not influenced by treatment or site. This study demonstrates that extensive ecosystem manipulation in the pinyon-juniper woodlands of northern Arizona did not affect understory richness or abundance the first year after treatment during a drought.

  6. Cost Methodology for Biomass Feedstocks: Herbaceous Crops and Agricultural Residues

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow Jr, Anthony F [ORNL; Webb, Erin [ORNL; Sokhansanj, Shahabaddine [ORNL

    2009-12-01

    This report describes a set of procedures and assumptions used to estimate production and logistics costs of bioenergy feedstocks from herbaceous crops and agricultural residues. The engineering-economic analysis discussed here is based on methodologies developed by the American Society of Agricultural and Biological Engineers (ASABE) and the American Agricultural Economics Association (AAEA). An engineering-economic analysis approach was chosen due to lack of historical cost data for bioenergy feedstocks. Instead, costs are calculated using assumptions for equipment performance, input prices, and yield data derived from equipment manufacturers, research literature, and/or standards. Cost estimates account for fixed and variable costs. Several examples of this costing methodology used to estimate feedstock logistics costs are included at the end of this report.

  7. Phenological synchrony and seasonality of understory Rubiaceae in the Atlantic Forest, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Heitor Scarpati Liuth

    2013-03-01

    Full Text Available In tropical forests with low seasonality, climatic variables generally exert a weak influence on the phenology of species. The seasonality of phenophases in closely related taxa can be controlled by phylogenetic constraints in such environments. In this study, our aim was to describe the phenology of Rubiaceae in the understory of the Atlantic Forest in the southern part of Bahia, Brazil, as well as to evaluate the seasonality and phenological synchrony of this family. For two years, we observed 90 individuals belonging to 13 species, in an area of 0.2 ha. Leaf flushing and leaf fall did not demonstrate any seasonality, were continuous for most species and correlated with few of the climatic variables. Flowering was seasonal and correlated positively with all climatic variables. Species exhibited seasonality for this phenophase with high flowering overlap among species of Psychotria, indicating an aggregated pattern for this genus. Fruiting was also seasonal and correlated with all the climatic variables, unripe fruit development peaking at the beginning of the season during which humidity is highest and fruit ripening peaking in the season during which humidity is slightly lower. The vegetative and flowering patterns observed in the study area are commonly seen in other tropical forests. The reproductive seasonality of this family can facilitate the attraction of biotic agents, as postulated in the facilitation hypothesis. Our results demonstrate that climatic variables influenced the phenological patterns observed here, although the high reproductive seasonality and interspecific synchrony, especially in congeneric species, raises the possibility that phylogenetic proximity plays a role in the pattern of the family Rubiaceae.

  8. Responses of herbaceous plants to urban air pollution: Effects on growth, phenology and leaf surface characteristics

    International Nuclear Information System (INIS)

    Honour, Sarah L.; Bell, J. Nigel B.; Ashenden, Trevor W.; Cape, J. Neil; Power, Sally A.

    2009-01-01

    Vehicle exhaust emissions are a dominant feature of urban environments and are widely believed to have detrimental effects on plants. The effects of diesel exhaust emissions on 12 herbaceous species were studied with respect to growth, flower development, leaf senescence and leaf surface wax characteristics. A diesel generator was used to produce concentrations of nitrogen oxides (NO x ) representative of urban conditions, in solardome chambers. Annual mean NO x concentrations ranged from 77 nl l -l to 98 nl l -1 , with NO:NO 2 ratios of 1.4-2.2, providing a good experimental simulation of polluted roadside environments. Pollutant exposure resulted in species-specific changes in growth and phenology, with a consistent trend for accelerated senescence and delayed flowering. Leaf surface characteristics were also affected; contact angle measurements indicated changes in surface wax structure following pollutant exposure. The study demonstrated clearly the potential for realistic levels of vehicle exhaust pollution to have direct adverse effects on urban vegetation. - Fumigation experiments demonstrate adverse effects of exhaust emissions on urban vegetation

  9. Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

    Directory of Open Access Journals (Sweden)

    Antonio Rigueiro-Rodríguez

    2012-02-01

    Full Text Available Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener and beta (Jaccard and Magurran biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing. Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

  10. Managing Understory Vegetation for Maintaining Productivity in Black Spruce Forests: A Synthesis within a Multi-Scale Research Model

    Directory of Open Access Journals (Sweden)

    Gilles Joanisse

    2013-07-01

    Full Text Available Sustainable management of boreal ecosystems involves the establishment of vigorous tree regeneration after harvest. However, two groups of understory plants influence regeneration success in eastern boreal Canada. Ericaceous shrubs are recognized to rapidly dominate susceptible boreal sites after harvest. Such dominance reduces recruitment and causes stagnant conifer growth, lasting decades on some sites. Additionally, peat accumulation due to Sphagnum growth after harvest forces the roots of regenerating conifers out of the relatively nutrient rich and warm mineral soil into the relatively nutrient poor and cool organic layer, with drastic effects on growth. Shifts from once productive black spruce forests to ericaceous heaths or paludified forests affect forest productivity and biodiversity. Under natural disturbance dynamics, fires severe enough to substantially reduce the organic layer thickness and affect ground cover species are required to establish a productive regeneration layer on such sites. We succinctly review how understory vegetation influences black spruce ecosystem dynamics in eastern boreal Canada, and present a multi-scale research model to understand, limit the loss and restore productive and diverse ecosystems in this region. Our model integrates knowledge of plant-level mechanisms in the development of silvicultural tools to sustain productivity. Fundamental knowledge is integrated at stand, landscape, regional and provincial levels to understand the distribution and dynamics of ericaceous shrubs and paludification processes and to support tactical and strategic forest management. The model can be adapted and applied to other natural resource management problems, in other biomes.

  11. Impacts of cwd on understory biodiversity in forest ecosystems in the qinling mountains, china

    International Nuclear Information System (INIS)

    Yuan, J.; Wei, X.; Shang, Z.; Cheng, F.; Hu, Z.; Zheng, X.; Zhang, S.

    2015-01-01

    The stocks and characteristics of coarse woody debris (CWD) are expected to reflect forest stand features. However, despite their importance, there have been no reports of CWD stocks and characteristics in the Qinling Mountains. We measured the CWD stocks in different CWD types, decay classes and diameter classes of the five forest types in the Qinling Mountains. The highest biomass of CWD was the Pinus tabulaeformis forest (12.57 t-hm /sup -2/), occupied 5.66 percentage in the biomass of this forest, the lowest occupied 1.03 percentage in Betula albo-sinensis forest (1.82 t-hm /sup -2/). Our results revealed that there was a strong correlation between CWD and forest biomass. When the CWD biomass were 9.9 t-hm /sup -2/ and 11.6 hm /sup -2/, the biomass of Pinus armandi forest and P. tabulaeformis forest reached maximum, respectively. CWD is particularly important for biodiversity, but the importance of CWD in the control of diversity in forest systems has not been fully appreciated and certainly has not been evaluated intensively within China, especially in Qinling forests. In our research, we used species richness (S), Shannon-Wiener index (H), Simpson index (D) and Pielou evenness index (J) to assess the diversity of plant community. According to our analysis, we found 1) the effect of CWD biomass on these a diversity index was dependent on tree, shrub and herb in the five forest types, 2) the impacts of CWD biomass on understory biodiversity were more obvious, 3) With the increase of CWD biomass, the species richness (S), Shannon-Wiener index (H) and Simpson index (D) of understory increased significantly. Our results suggested that there was a relatively lower CWD biomass in the Qinling Mountains, but it had significant effects on forest biomass and diversity of plant community. Reserving CWD was important for eco-forestry, but how many and how characteristic of CWD should be retained need further research. Development of CWD reasonable strategies was

  12. Herbaceous vegetation restoration potential and soil physical condition in a mountain grazing land of Eastern Tigray, Ethiopia

    Directory of Open Access Journals (Sweden)

    Gebrewahd Amha Abesha

    2014-06-01

    Full Text Available An existence of information in the form database and full knowledge of grazing land vegetation resources and trend over time is essential for management decisions. This study was conducted in Kiltew -Awelaelo, eastern Tigray, Ethiopia. The study aimed to investigate species composition and diversity of the herbaceous vegetation, and examine the physical soil condition of the grazing lands. A total of 45 quadrats measuring 20m×20m (400m2 were laid out in 15 sample sites from three corresponding land use types (i.e. ten year enclosure, five year enclosure and open grazing land. From each land use type five sites having three quadrats were investigated. Each quadrat was laid out at an interval of 400m in five parallel transects each 200m apart from other. To collect data of herbaceous and soil five randomly located 1m2 area each, was selected and marked, within each 400m2 sample quadrat of sample sites located along the main transect. There was significant (PBracharia sp., Bromus pectinatus, Chloris gayana, Cenchurs cilarias, chloris radiata, Cynodon dactylon, Dactyloctenium aegyptium, Digitaria Velutina, Eragrostis teniufolia, Lintonia nutans, Setaria pumila, Seteria verticillate, and Tragus racemosus all occurred frequently forming the major constituents of the sites. Therefore, regeneration from area enclosure can be on advocated practice for grazing lands rehabilitation.

  13. Static terrestrial laser scanning of juvenile understory trees for field phenotyping

    Science.gov (United States)

    Wang, Huanhuan; Lin, Yi

    2014-11-01

    This study was to attempt the cutting-edge 3D remote sensing technique of static terrestrial laser scanning (TLS) for parametric 3D reconstruction of juvenile understory trees. The data for test was collected with a Leica HDS6100 TLS system in a single-scan way. The geometrical structures of juvenile understory trees are extracted by model fitting. Cones are used to model trunks and branches. Principal component analysis (PCA) is adopted to calculate their major axes. Coordinate transformation and orthogonal projection are used to estimate the parameters of the cones. Then, AutoCAD is utilized to simulate the morphological characteristics of the understory trees, and to add secondary branches and leaves in a random way. Comparison of the reference values and the estimated values gives the regression equation and shows that the proposed algorithm of extracting parameters is credible. The results have basically verified the applicability of TLS for field phenotyping of juvenile understory trees.

  14. Understory plant diversity in mixed and pure plantations of jatropha curcas vs. native vegetation in the lower-middle reaches of the lancang-meikong river watershed, china

    International Nuclear Information System (INIS)

    Ou, G.L.; Ma, H.C.; Tang, J.R.

    2015-01-01

    22 plots at the Xiaoheijiang base, located in the lower-middle reaches of the Lancang-Meikong River in China, were investigated to analyze the understory biodiversity of Jatropha curcas plantations. Two kinds of mixed modes of J. curcas (mixed plantation with Macadamia integrifolia and mixed plantation with shrub species) and a pure plantation of J. curcas were planted, while the native vegetation served as a control. The plots were distributed along the gradients of forest management, succession and elevation by CCA analysis. Species richness was not significantly different for the different types of plantation, but the evenness of species could be affected, especially for the total community and the understory by planting J. curcas. The diversity and evenness indices of species were affected for the mixed plantation with different proportions of M. integrifolia, especially for the shrub layer, the Shannon diversity index and Pilou evenness index showed significant differences. And for the different mixed shrub species, only the Shannon diversity index and Pilou evenness index were significantly different. Finally, from the perspective of biological diversity, J.curcas plantation with shrub species would be a recommended planting model for ecological restoration in a dry-hot valley area, while J. curcas plantation with M. integrifolia would be an effective planting model to balance crop yield and food security. (author)

  15. Herbaceous energy crops: a general survey and a microeconomic analysis

    International Nuclear Information System (INIS)

    Caserta, G.

    1995-01-01

    Liquid fuels (bioethanol and biooil) derived from herbaceous crops are considered beneficial for the environment and human health especially if they are used as fuels for motor vehicles. The choice of the most suited crop to be cultivated for liquid biofuel production depends on many factors; the most important being the economic convenience for farmers to cultivate the new energy crop in place of the traditional ones. In order to analyse the conditions which favour the cultivation and selling of specific energy crops, a simple methodology is proposed, based on the calculation of the ''threshold price'' of the energy crop products. The ''threshold price'' is the minimum price at which the primary products of the energy crop, i.e., roots, tubers, seeds, etc., must be sold in order to obtain a gross margin equal to that usually obtained from the traditional crop which is replaced by the energy crop. As a case-study, this methodology has been applied to twelve Italian provinces where the cultivation of six energy crops, both in productive lands and set-aside lands, is examined. The crops considered are sugar beet, sweet sorghum and topinambour, useful for bioethanol production; and rapeseed, sunflower and soya, which are usually employed for the production of biooil. (Author)

  16. Symbiotic Performance of Herbaceous Legumes in Tropical Cover Cropping Systems

    Directory of Open Access Journals (Sweden)

    Basil Ibewiro

    2001-01-01

    Full Text Available Increasing use of herbaceous legumes such as mucuna (Mucuna pruriens var. utilis [Wright] Bruck and lablab (Lablab purpureus [L.] Sweet in the derived savannas of West Africa can be attributed to their potential to fix atmospheric nitrogen (N2. The effects of management practices on N2 fixation in mucuna and lablab were examined using 15N isotope dilution technique. Dry matter yield of both legumes at 12 weeks was two to five times more in in situ mulch (IM than live mulch (LM systems. Land Equivalent Ratios, however, showed 8 to 30% more efficient utilization of resources required for biomass production under LM than IM systems. Live mulching reduced nodule numbers in the legumes by one third compared to values in the IM systems. Similarly, nodule mass was reduced by 34 to 58% under LM compared to the IM systems. The proportion of fixed N2 in the legumes was 18% higher in LM than IM systems. Except for inoculated mucuna, the amounts of N fixed by both legumes were greater in IM than LM systems. Rhizobia inoculation of the legumes did not significantly increase N2 fixation compared to uninoculated plots. Application of N fertilizer reduced N2 fixed in the legumes by 36 to 51% compared to inoculated or uninoculated systems. The implications of cover cropping, N fertilization, and rhizobia inoculation on N contributions of legumes into tropical low-input systems were discussed.

  17. Herbaceous energy crops in humid lower South USA

    Energy Technology Data Exchange (ETDEWEB)

    Prine, G.M.; Woodard, K.R. [Univ. of Florida, Gainesville, FL (United States)

    1993-12-31

    The humid lower South has the long warm growing season and high rainfall conditions needed for producing high-yielding perennial herbaceous grasses and shrubs. Many potential biomass plants were evaluated during a ten-year period. Perennial tall grasses such as elephantgrass (Pennisetum purpureum), sugarcane and energycane (Saccharum spp.) and the leguminous shrub Leucaena leucocephala were the highest in biomass production. These perennial crops often have top growth killed by winter freezes and regenerate from underground parts. The tall grasses have high yields because of linear crop growth rates of 18 to 27 g m{sup 2} d{sup {minus}1} for long periods (140 to 196 d) each season. Tall grasses must be planted vegetatively, which is more costly than seed propagation, however, once established, they may persist for many seasons. Oven dry biomass yields have varied from 20 to 45 Mg ha{sup {minus}1} yr{sup {minus}1} in colder subtropical to mild temperate locations to over 60 Mg ha{sup {minus}1} yr{sup {minus}1} in the lower portion of the Florida peninsular. Highest biomass yields have been produced when irrigated with sewage effluent or when grown on phosphatic clay and muck soils in south Florida. The energy content of 1 Mg of oven dry tall grass and leucaena is equivalent to that of about 112 and 123 gallons of number 2 diesel fuel, respectively.

  18. Evaluation de la diversité floristique en herbacées dans le Parc ...

    African Journals Online (AJOL)

    1. Phyllanthaceae. Phyllanthus maderaspatensis L. 1. Polygalaceae. Polygala petitiana A. Rich. 1. Portulacaceae. Portulaca quadrifida L. 1. Total. 23. DISCUSSION. Les résultats de cette étude fournissent des informations sur l'état actuel de la végétation herbacée du PNM au Tchad. La végétation herbacée de la zone du.

  19. Edge effects on understory epiphytic ferns and epiphyllous bryophytes in moist afromontane forests of Ethiopia

    Directory of Open Access Journals (Sweden)

    Hylander Kristoffer

    2013-12-01

    Full Text Available Most studies on edge effects in tropical forests have been conducted in landscapes with low human population density and in situations where the edges have been left unused after logging of the adjacent area. Here we studied forest margins heavily used by local farmers in a forest/agriculture mosaic landscape in Ethiopia. We compared forest structure and plant species composition across 41 forest-agriculture ecotones from 200 m out into the agricultural area to 200 m into the forest. There are strong edge effects from the edge and into the forest on canopy cover and number of stumps and apparently these forest-agricultural edges are intensively used by humans. They are penetrated by paths, beehives are found in the trees, timber of various dimensions is harvested and there is sometimes substantial cover of perennial wild (or semi-wild crops such as coffee and spices. The number of understory epiphytic fern species as well as number of epiphyllous (i.e., growing on leaves bryophyte species was lower at 20 m than at 75 m from the edge. The number of fern species was higher in newly created edges and thereafter they declined, which indicates an extinction debt. This pattern was not seen for the epiphyllous bryophytes. It is likely that different human management activities are responsible for many of the found edge effects besides wind and sun effects from the edge. Tropical forest margins provide important resources for people in many landscapes. It is important to understand how such use affects the biota of the forests. This study shows that there are substantial edge effects, but that the edge effects do not seem to become worse over time for epiphyllous bryophytes and only slightly so for ferns.

  20. Burn Severity Dominates Understory Plant Community Response to Fire in Xeric Jack Pine Forests

    Directory of Open Access Journals (Sweden)

    Bradley D. Pinno

    2016-04-01

    Full Text Available Fire is the most common disturbance in northern boreal forests, and large fires are often associated with highly variable burn severities across the burnt area. We studied the understory plant community response to a range of burn severities and pre-fire stand age four growing seasons after the 2011 Richardson Fire in xeric jack pine forests of northern Alberta, Canada. Burn severity had the greatest impact on post-fire plant communities, while pre-fire stand age did not have a significant impact. Total plant species richness and cover decreased with disturbance severity, such that the greatest richness was in low severity burns (average 28 species per 1-m2 quadrat and plant cover was lowest in the high severity burns (average 16%. However, the response of individual plant groups differed. Lichens and bryophytes were most common in low severity burns and were effectively eliminated from the regenerating plant community at higher burn severities. In contrast, graminoid cover and richness were positively related to burn severity, while forbs did not respond significantly to burn severity, but were impacted by changes in soil chemistry with increased cover at pH >4.9. Our results indicate the importance of non-vascular plants to the overall plant community in this harsh environment and that the plant community is environmentally limited rather than recruitment or competition limited, as is often the case in more mesic forest types. If fire frequency and severity increase as predicted, we may see a shift in plant communities from stress-tolerant species, such as lichens and ericaceous shrubs, to more colonizing species, such as certain graminoids.

  1. Impact of understory vegetation on soil carbon and nitrogen dynamic in aerially seeded Pinus massoniana plantations

    Science.gov (United States)

    Pan, Ping; Zhao, Fang; Ning, Jinkui; Ouyang, Xunzhi; Zang, Hao

    2018-01-01

    Understory vegetation plays a vital role in regulating soil carbon (C) and nitrogen (N) characteristics due to differences in plant functional traits. Different understory vegetation types have been reported following aerial seeding. While aerial seeding is common in areas with serious soil erosion, few studies have been conducted to investigate changes in soil C and N cycling as affected by understory vegetation in aerially seeded plantations. Here, we studied soil C and N characteristics under two naturally formed understory vegetation types (Dicranopteris and graminoid) in aerially seeded Pinus massoniana Lamb plantations. Across the two studied understory vegetation types, soil organic C was significantly correlated with all measured soil N variables, including total N, available N, microbial biomass N and water-soluble organic N, while microbial biomass C was correlated with all measured variables except soil organic C. Dicranopteris and graminoid differed in their effects on soil C and N process. Except water-soluble organic C, all the other C and N variables were higher in soils with graminoids. The higher levels of soil organic C, microbial biomass C, total N, available N, microbial biomass N and water-soluble organic N were consistent with the higher litter and root quality (C/N) of graminoid vegetation compared to Dicranopteris. Changes in soil C and N cycles might be impacted by understory vegetation types via differences in litter or root quality. PMID:29377926

  2. Remote Sensing-based estimates of herbaceous aboveground biomass on the Mongolian Plateau

    Science.gov (United States)

    John, R.; Chen, J.; Kim, Y.; Ouyang, Z.; Park, H.; Shao, C.

    2015-12-01

    Grasslands comprise most of the land area on the Mongolian Plateau, which includes Mongolia (MG), and the province of Inner Mongolia (IM). Substantial land cover/use change in the recent past, driven by a combination of post-liberalization, socio-economic changes as well as extreme climatic events has resulted in degradation of grasslands in structure and function, for e.g., their carbon sequestration ability. Hence there is a need for precise estimation of above-ground biomass (AGB). In this study, we collected surface reflectance spectra from field radiometry and quadrats and line transects, which include percentage of ground cover, vegetation height, above ground biomass, and species richness, during the growing season, between the periods, 2006-2011 in IM and 2011-2015 in MG. The field sampling was stratified by the dominant vegetation types on the plateau, including the meadow steppe, typical steppe, and the desert steppe. These sampling data were used as training and validation data for developing and testing predictive models for total herbaceous vegetation, and AGB, using Landsat and MODIS-surface reflectance bands and derived vegetation indices optimized for low cover conditions. Our results show that the independent ground sampling data were significantly correlated with remotely sensed estimates. In addition to providing measures of carbon sequestration to the community, these predictive models offer decision makers and rangeland managers the ability to accurately monitor grassland dynamics, control livestock stocking rates in these remote and extensive grasslands.

  3. Recent assembly of the global herbaceous flora: evidence from the paper daisies (Asteraceae: Gnaphalieae).

    Science.gov (United States)

    Nie, Ze-Long; Funk, Vicki A; Meng, Ying; Deng, Tao; Sun, Hang; Wen, Jun

    2016-03-01

    The global flora is thought to contain a large proportion of herbs, and understanding the general spatiotemporal processes that shaped the global distribution of these communities is one of the most difficult issues in biogeography. We explored patterns of world-wide biogeography in a species-rich herbaceous group, the paper daisy tribe Gnaphalieae (Asteraceae), based on the hitherto largest taxon sampling, a total of 835 terminal accessions representing 80% of the genera, and encompassing the global geographic range of the tribe, with nuclear internal transcribed spacer (ITS) and external transcribed spacer (ETS) sequences. Biogeographic analyses indicate that Gnaphalieae originated in southern Africa during the Oligocene, followed by repeated migrations into the rest of Africa and the Mediterranean region, with subsequent entries into other continents during various periods starting in the Miocene. Expansions in the late Miocene to Pliocene appear to have been the driving force that shaped the global distribution of the tribe as forests were progressively broken up by the mid-continent aridification and savannas and grasslands expanded into the interior of the major continents. This pattern of recent colonizations may explain the world-wide distribution of many other organisms in open ecosystems and it is highlighted here as an emerging pattern in the evolution of the global flora. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. The impact of forest roads on understory plant diversity in temperate hornbeam-beech forests of Northern Iran.

    Science.gov (United States)

    Deljouei, Azade; Abdi, Ehsan; Marcantonio, Matteo; Majnounian, Baris; Amici, Valerio; Sohrabi, Hormoz

    2017-08-01

    Forest roads alter the biotic and abiotic components of ecosystems, modifying temperature, humidity, wind speed, and light availability that, in turn, cause changes in plant community composition and diversity. We aim at investigating and comparing the diversity of herbaceous species along main and secondary forest roads in a temperate-managed hornbeam-beech forest, north of Iran. Sixteen transects along main and secondary forest roads were established (eight transects along main roads and eight along secondary roads). To eliminate the effect of forest type, all transects were located in Carpinetum-Fagetum forests, the dominant forest type in the study area. The total length of each transect was 200 m (100 m toward up slope and 100 m toward down slope), and plots were established along it at different distances from road edge. The diversity of herbaceous plant species was calculated in each plot using Shannon-Wiener index, species richness, and Pielou's index. The results showed that diversity index decreased when distance from road edge increases. This decreasing trend continued up to 60 m from forest road margin, and after this threshold, the index slightly increased. Depending on the type of road (main or secondary) as well as cut or fill slopes, the area showing a statistical different plant composition and diversity measured through Shannon-Wiener, species richness, and Pielou's index is up to 10 m. The length depth of the road edge effect found in main and secondary forest roads was small, but it could have cumulative effects on forest microclimate and forest-associated biota at the island scale. Forest managers should account for the effect of road buildings on plant communities.

  5. Assessing atmospheric particulate matter distribution based on Saturation Isothermal Remanent Magnetization of herbaceous and tree leaves in a tropical urban environment.

    Science.gov (United States)

    Barima, Yao Sadaiou Sabas; Angaman, Djédoux Maxime; N'gouran, Kobenan Pierre; Koffi, N'guessan Achille; Kardel, Fatemeh; De Cannière, Charles; Samson, Roeland

    2014-02-01

    Particulate matter (PM) emissions, and the associated human health risks, are likely to continue increasing in urban environments of developing countries like Abidjan (Ivory Cost). This study evaluated the potential of leaves of several herbaceous and tree species as bioindicators of urban particulate matter pollution, and its variation over different land use classes, in a tropical area. Four species well distributed (presence frequencies >90%) over all land use classes, easy to harvest and whose leaves are wide enough to be easily scanned were selected, i.e.: Amaranthus spinosus (Amaranthaceae), Eleusine indica (Poaceae), Panicum maximum (Poaceae) and Ficus benjamina (Moraceae). Leaf sampling of these species was carried out at 3 distances from the road and at 3 height levels. Traffic density was also noted and finally biomagnetic parameters of these leaves were determined. Results showed that Saturation Isothermal Remanent Magnetization (SIRM) of leaves was at least 4 times higher (27.5×10(-6)A) in the vicinity of main roads and industrial areas than in parks and residential areas. The main potential sources of PM pollution were motor vehicles and industries. The slightly hairy leaves of the herbaceous plant A. spinosus and the waxy leaves of the tree F. benjamina showed the highest SIRM (25×10(-6)A). Leaf SIRM increased with distance to road (R(2)>0.40) and declined with sampling height (R(2)=0.17). The distance between 0 and 5m from the road seemed to be the most vulnerable in terms of PM pollution. This study has showed that leaf SIRM of herbaceous and tree species can be used to assess PM exposure in tropical urban environments. © 2013.

  6. 50 CFR 15.32 - Criteria for including species in the approved list for non-captive-bred species.

    Science.gov (United States)

    2010-10-01

    ... Management and Scientific Authorities transmitting the management plan of this species; (iii) A summary of... where the species forages (aerial feeder, tree canopy, tree trunk, midstory, understory, open water or..., disease carrier; a description of the damage the pest species causes to its ecosystem; and a description...

  7. Effect of overstory on the seasonal variability of understory herbs in ...

    African Journals Online (AJOL)

    SAM

    2014-03-12

    Mar 12, 2014 ... diversity and soil attributes, light environment at herbaceous layer, as well as the tree and shrub layer, indicated that ..... The author(s) have not declared any conflict of interests. ... layers. Forest Ecology and Management.

  8. Impacts of Panicum maximum Jacq. invasion and its manual weeding on the wood plant regeneration in the understory of a restoration site Efeitos da invasão por Panicum maximum Jacq. e do seu controle manual sobre a regeneração de plantas lenhosas no sub-bosque de um reflorestamento

    Directory of Open Access Journals (Sweden)

    Gabriela Ribeiro de Andrade

    2012-06-01

    Full Text Available Responsible for considerable annual losses of biodiversity in natural ecosystems, invasive alien species cause important conservation problems, leading native species to local extinction. This study examined the relationship among the coverage of Guinea-grass (Panicum maximum Jacq., its manual weeding and the woody plant diversity of a restoration site. The site is a reforestation created using native species but due to spacing and species composition grass still dominates its understory more than 17 years after. Preliminary results showed that it is a barrier to the establishment of native species. In this study, we established 20 plots of 5m x 5m divided into two treatments, control and removal of P. maximum, to investigate the impact of manual weeding on the understory in a period of 90 days. Grass cover and canopy openness were also recorded. The grass cover had negative correlation with the abundance of plants, with the species richness and abundance of tree species. Canopy openness had a negative influence on the species richness, on abundance and richness of tree species, but not showed correlation with P. maximum. After grass removal, both abundance of seedling and species richness had no significant differences, so the manual weeding did not cause a negative impact in short time on the regeneration of the understory due to accidental native plant uprooting. However, a positive impact is expected only after a longer period of observation, after successive removals of invasive herbaceous and increased chance of colonization of the area by regenerating seedlings.Responsáveis por perdas anuais consideráveis na biodiversidade dos ecossistemas naturais, as espécies exóticas invasoras causam sérios problemas à conservação, levando muitas espécies à extinção local. Este estudo analisou o efeito da cobertura de capim-colonião (Panicum maximum Jacq. no sub-bosque de um reflorestamento dominado há mais de 17 anos por essa gram

  9. Interactions between Canopy Structure and Herbaceous Biomass along Environmental Gradients in Moist Forest and Dry Miombo Woodland of Tanzania.

    Directory of Open Access Journals (Sweden)

    Deo D Shirima

    Full Text Available We have limited understanding of how tropical canopy foliage varies along environmental gradients, and how this may in turn affect forest processes and functions. Here, we analyse the relationships between canopy leaf area index (LAI and above ground herbaceous biomass (AGBH along environmental gradients in a moist forest and miombo woodland in Tanzania. We recorded canopy structure and herbaceous biomass in 100 permanent vegetation plots (20 m × 40 m, stratified by elevation. We quantified tree species richness, evenness, Shannon diversity and predominant height as measures of structural variability, and disturbance (tree stumps, soil nutrients and elevation as indicators of environmental variability. Moist forest and miombo woodland differed substantially with respect to nearly all variables tested. Both structural and environmental variables were found to affect LAI and AGBH, the latter being additionally dependent on LAI in moist forest but not in miombo, where other factors are limiting. Combining structural and environmental predictors yielded the most powerful models. In moist forest, they explained 76% and 25% of deviance in LAI and AGBH, respectively. In miombo woodland, they explained 82% and 45% of deviance in LAI and AGBH. In moist forest, LAI increased non-linearly with predominant height and linearly with tree richness, and decreased with soil nitrogen except under high disturbance. Miombo woodland LAI increased linearly with stem density, soil phosphorous and nitrogen, and decreased linearly with tree species evenness. AGBH in moist forest decreased with LAI at lower elevations whilst increasing slightly at higher elevations. AGBH in miombo woodland increased linearly with soil nitrogen and soil pH. Overall, moist forest plots had denser canopies and lower AGBH compared with miombo plots. Further field studies are encouraged, to disentangle the direct influence of LAI on AGBH from complex interrelationships between stand

  10. Interactions between Canopy Structure and Herbaceous Biomass along Environmental Gradients in Moist Forest and Dry Miombo Woodland of Tanzania.

    Science.gov (United States)

    Shirima, Deo D; Pfeifer, Marion; Platts, Philip J; Totland, Ørjan; Moe, Stein R

    2015-01-01

    We have limited understanding of how tropical canopy foliage varies along environmental gradients, and how this may in turn affect forest processes and functions. Here, we analyse the relationships between canopy leaf area index (LAI) and above ground herbaceous biomass (AGBH) along environmental gradients in a moist forest and miombo woodland in Tanzania. We recorded canopy structure and herbaceous biomass in 100 permanent vegetation plots (20 m × 40 m), stratified by elevation. We quantified tree species richness, evenness, Shannon diversity and predominant height as measures of structural variability, and disturbance (tree stumps), soil nutrients and elevation as indicators of environmental variability. Moist forest and miombo woodland differed substantially with respect to nearly all variables tested. Both structural and environmental variables were found to affect LAI and AGBH, the latter being additionally dependent on LAI in moist forest but not in miombo, where other factors are limiting. Combining structural and environmental predictors yielded the most powerful models. In moist forest, they explained 76% and 25% of deviance in LAI and AGBH, respectively. In miombo woodland, they explained 82% and 45% of deviance in LAI and AGBH. In moist forest, LAI increased non-linearly with predominant height and linearly with tree richness, and decreased with soil nitrogen except under high disturbance. Miombo woodland LAI increased linearly with stem density, soil phosphorous and nitrogen, and decreased linearly with tree species evenness. AGBH in moist forest decreased with LAI at lower elevations whilst increasing slightly at higher elevations. AGBH in miombo woodland increased linearly with soil nitrogen and soil pH. Overall, moist forest plots had denser canopies and lower AGBH compared with miombo plots. Further field studies are encouraged, to disentangle the direct influence of LAI on AGBH from complex interrelationships between stand structure, environmental

  11. Effects of radiation, litterfall and throughfall on herbaceous biomass production in oak woodlands of Southern Portugal

    International Nuclear Information System (INIS)

    Nunes, J.; Sa, C.; Madeira, M.; Gazarini, L.

    2002-01-01

    Micro climatic characteristics (soil moisture, and air and soil temperature) were monitored both under and outside the influence of Quercus rotundifolia canopy. The influence of tree cover on biomass production of herbaceous vegetation was studied through the simulation of the physical and chemical effects associated to the tree canopy (radiation, litterfall, throughfall). Treatments were: control (T), radiation shortage (RR), application of leaf litter (F), application of leaflitter and radiation shortage (FRR) , application of throughfall (N) and application of throughfall and radiation shortage (NRR). Most of the times, and especially in winter, soil temperature was higher in areas not influenced by the canopies than in those under their influence. Soil moisture tended to decrease faster in the areas outside the canopy influence. Mean annual biomass production of the herbaceous vegetation was 159.5, 145.8, 132.2, 126.66, 134.9 and 173.1 g m2, respectively, in treatments C, RR, F, FRR, N and NRR. The N, P, K, Mg, Mn and Ca concentrations in the herbaceous biomass were generally higher in the shaded treatments. When the amount of nutrients accumulated in the herbaceous vegetation biomass was expressed on an area basis, the highest values were observed for treatment with throughfall application and radiation shortage. Besides the possible effects of the micro climatic characteristics, differences with respect to herbaceous vegetation production may be explained by the presence of litterfall, as well as by the nutrients present in the throughfall solution [pt

  12. Diagnosis of vegetation recovery within herbaceous sub-systems in the West African Sahel Region

    Science.gov (United States)

    Anchang, J.; Hanan, N. P.; Prihodko, L.; Sathyachandran, S. K.; Ji, W.; Ross, C. W.

    2017-12-01

    The West African Sahel (WAS) region is an extensive water limited environment that features a delicate balance of herbaceous and woody vegetation sub systems. These play an important role in the cycling of carbon while also supporting the dominant agro-pastoral human activities in the region. Quantifying the temporal trends in vegetation with regard to these two systems is therefore very important in assessing resource sustainability and food security. In water limited areas, rainfall is a primary driver of vegetation productivity and past watershed scale studies in the WAS region have shown that increase in the slope of the productivity-to-rainfall relationship is indicative of increasing cover and density of herbaceous plants. Given the importance of grazing resources to the region, we perform a wall-to-wall pixel based analysis of changing short-term vegetation sensitivity to changing annual rainfall (hereafter referred to as dS) to examine temporal trends in herbaceous vegetation health. Results indicate that 43% of the Sahelian region has experienced changes (P Western and Central Mali and South Western Niger. Positive dS is indicative of herbaceous vegetation recovery, in response to changing management and rainfall conditions that promote long-term herbaceous community recovery following degradation during the 1970-1980s droughts.

  13. Floristic survey of the herbaceous-shrub layer of a gallery forest in Alto Paraíso de Goiás - GO, Brazil

    Directory of Open Access Journals (Sweden)

    Eduardo Chaves

    2012-10-01

    Full Text Available Flowering species of the herbaceous and shrubby layer were sampled in a gallery forest at Portal da Chapada, Alto Paraíso de Goiás-GO in the Chapada dos Veadeiros during 12 months growing within 4.5 meters on either side of a raised pathway 2.4 Km long. The collections were included to University of Brasilia Herbarium (UB. A total of 138 species (103 genera and 40 families were recorded; the most species-rich families were Asteraceae (22, Poaceae (14, Rubiaceae (12, Fabaceae (11 and Melastomataceae (7. The richest family in number of genera was Asteraceae (19, followed by Poaceae (8, Fabaceae (8 and Rubiaceae (7. The results showed a meaningful increase in the Chapada dos Veadeiros flora, especially considering the herbaceous-shrubby layer of the gallery forests (223.6%. Despite the richness of the flora, the number of endemics species in the Goiás State was only 1.5%.

  14. Presence of understory shrubs constrains carbon gain in sunflecks by advance-regeneration seedlings: evidence from Quercus Rubra seedling grouwing in understory forest patches with or without evergreen shrubs present

    Science.gov (United States)

    E.T. Nilsen; T.T. Lei; S.W. Semones

    2009-01-01

    We investigated whether dynamic photosynthesis of understory Quercus rubra L. (Fagaceae) seedlings can acclimate to the altered pattern of sunflecks in forest patches with Rhododendron maximum L. (Ericaceae), an understory evergreen shrub. Maximum photosynthesis (A) and total CO2 accumulated during lightflecks was greatest for 400-s lightflecks, intermediate for 150-s...

  15. Multi-Polarization ASAR Backscattering from Herbaceous Wetlands in Poyang Lake Region, China

    Directory of Open Access Journals (Sweden)

    Huiyong Sang

    2014-05-01

    Full Text Available Wetlands are one of the most important ecosystems on Earth. There is an urgent need to quantify the biophysical parameters (e.g., plant height, aboveground biomass and map total remaining areas of wetlands in order to evaluate the ecological status of wetlands. In this study, Environmental Satellite/Advanced Synthetic Aperture Radar (ENVISAT/ASAR dual-polarization C-band data acquired in 2005 is tested to investigate radar backscattering mechanisms with the variation of hydrological conditions during the growing cycle of two types of herbaceous wetland species, which colonize lake borders with different elevation in Poyang Lake region, China. Phragmites communis (L. Trin. is semi-aquatic emergent vegetation with vertical stem and blade-like leaves, and the emergent Carex spp. has rhizome and long leaves. In this study, the potential of ASAR data in HH-, HV-, and VV-polarization in mapping different wetland types is examined, by observing their dynamic variations throughout the whole flooding cycle. The sensitivity of ASAR backscattering coefficients to vegetation parameters of plant height, fresh and dry biomass, and vegetation water content is also analyzed for Phragmites communis (L. Trin. and Carex spp. The research for Phragmites communis (L. Trin. shows that HH polarization is more sensitive to plant height and dry biomass than HV polarization. ASAR backscattering coefficients are relatively less sensitive to fresh biomass, especially in HV polarization. However, both are highly dependent on canopy water content. In contrast, the dependence of HH- and HV- backscattering from Carex community on vegetation parameters is poor, and the radar backscattering mechanism is controlled by ground water level.

  16. Water level effect on herbaceous plant assemblages at an artificial reservoir-Lago Azul State Park, Southern Brazil

    Directory of Open Access Journals (Sweden)

    D. C. Souza

    Full Text Available This study presents the effect of water level variation on the assemblages of herbaceous species in Mourão I Reservoir, Lago Azul State Park, Southern Brazil. The structure and distribution of populations was examined in February (dry period and April (rainy period, 2011, in two transects. These transects started at the forest edge towards the center of the lake. The end of the transect coincided with the end of the plants within the lake. On every two meters along of the transects we sampled a wooden square of 0.25 m2 for species biomass analysis.The macrophyte stand was composed entirely of emergent species. Considering the periods, most species were less frequent in the rainy period (April, but Ipomea ramosissima (Poir. Choisy, Commelina nudiflora L., Eleocharis acuntagula (Roxb. Schult. and Verbena litorales (Kunth. had their frequency increased during this period, probably due to their resistance. The influence of flood as measured by the NMDS point out that both before and after the flood, there are plots with distinct compositions and biomass. The water level variation affects the dynamics of plant composition and structure in marginal areas of the Reservoir.

  17. Effects of a wind farm installation on the understory bat community of a highly biodiverse tropical region in Mexico

    Directory of Open Access Journals (Sweden)

    Miguel Briones-Salas

    2017-06-01

    Full Text Available Wind energy has rapidly become an important alternative among renewable energies, and it is generally considered clean. However, little is known about its impact at the level of ecological communities, especially in biodiversity hotspots. The Isthmus of Tehuantepec is a highly biodiverse region in Mesoamerica, and has the highest potential for generating wind energy in Mexico. To assess the effects of installing a wind farm on the understory bat community in a landscape of fragmented habitat, we assessed its diversity and composition over four stages of installation (site preparation, construction, and two stages of operation. We captured 919 bats belonging to 22 species. Species richness, functional diversity and phylogenetic diversity decreased during construction and the first stage of operation. However, these components of biodiversity increased during the second stage of operation, and species composition began to resemble that of the site preparation stage. No species considered as sensitive to disturbance was recorded at any stage. This is the first study to reveal the diversity of a Neotropical bat community after wind turbines begin to operate.

  18. Effects of a wind farm installation on the understory bat community of a highly biodiverse tropical region in Mexico

    Science.gov (United States)

    Lavariega, Mario C.; Moreno, Claudia E.

    2017-01-01

    Wind energy has rapidly become an important alternative among renewable energies, and it is generally considered clean. However, little is known about its impact at the level of ecological communities, especially in biodiversity hotspots. The Isthmus of Tehuantepec is a highly biodiverse region in Mesoamerica, and has the highest potential for generating wind energy in Mexico. To assess the effects of installing a wind farm on the understory bat community in a landscape of fragmented habitat, we assessed its diversity and composition over four stages of installation (site preparation, construction, and two stages of operation). We captured 919 bats belonging to 22 species. Species richness, functional diversity and phylogenetic diversity decreased during construction and the first stage of operation. However, these components of biodiversity increased during the second stage of operation, and species composition began to resemble that of the site preparation stage. No species considered as sensitive to disturbance was recorded at any stage. This is the first study to reveal the diversity of a Neotropical bat community after wind turbines begin to operate. PMID:28630802

  19. Effects of a wind farm installation on the understory bat community of a highly biodiverse tropical region in Mexico.

    Science.gov (United States)

    Briones-Salas, Miguel; Lavariega, Mario C; Moreno, Claudia E

    2017-01-01

    Wind energy has rapidly become an important alternative among renewable energies, and it is generally considered clean. However, little is known about its impact at the level of ecological communities, especially in biodiversity hotspots. The Isthmus of Tehuantepec is a highly biodiverse region in Mesoamerica, and has the highest potential for generating wind energy in Mexico. To assess the effects of installing a wind farm on the understory bat community in a landscape of fragmented habitat, we assessed its diversity and composition over four stages of installation (site preparation, construction, and two stages of operation). We captured 919 bats belonging to 22 species. Species richness, functional diversity and phylogenetic diversity decreased during construction and the first stage of operation. However, these components of biodiversity increased during the second stage of operation, and species composition began to resemble that of the site preparation stage. No species considered as sensitive to disturbance was recorded at any stage. This is the first study to reveal the diversity of a Neotropical bat community after wind turbines begin to operate.

  20. Ontogenetic stage, plant vigor and sex mediate herbivory loads in a dioecious understory herb

    Science.gov (United States)

    Selaković, Sara; Vujić, Vukica; Stanisavljević, Nemanja; Jovanović, Živko; Radović, Svetlana; Cvetković, Dragana

    2017-11-01

    Plant-herbivore interactions can be mediated by plant apparency, defensive and nutritional quality traits that change through plant ontogeny, resulting in age-specific herbivory. In dioecious species, opposing allocation patterns in defense may lead to sex-biased herbivory. Here, we examine how onto stage and plant sex determine levels of herbivore damage in understory herb Mercurialis perennis under field conditions. We analyzed variation in plant size (height, total leaf area), physical (specific leaf area) and chemical (total phenolic and condensed tannins contents) defense, and nutritional quality (total water, soluble protein and nonstructural carbohydrate contents) during the shift from reproductive to post-reproductive stage. Furthermore, we explored correlations between the analyzed traits and levels of foliar damage. Post-reproductive plants had lower levels of chemical defense, and larger leaf area removed, in spite of having lower nutritive quality. Opposing patterns of intersexual differences were detected in protein and phenolic contents during reproductive stage, while in post-reproductive stage total leaf area was sexually dimorphic. Female-biased herbivory was apparent only after reproduction. Plant size parameters combined with condensed tannins content determined levels of foliar damage during post-reproductive stage, while the only trait covarying with herbivory in reproductive stage was total nonstructural carbohydrate content. Our results support claims of optimal defense theory - sensitive stage of reproduction was better defended. We conclude that different combinations of plant traits mediated interactions with herbivores in mature stages. Differences in reproductive allocation between the sexes may not immediately translate into different levels of damage, stressing the need for considering different ontogenetic stages when exploring sex bias in herbivory.

  1. Response of herbaceous plant community diversity and composition to overstorey harvest within riparian management zones in Northern Hardwoods

    Science.gov (United States)

    Eric K. Zenner; Michelle A. Martin; Brian J. Palik; Jerilynn E. Peck; Charles R. Blinn

    2013-01-01

    Partial timber harvest within riparian management zones (RMZs) may permit active management of riparian forests while protecting stream ecosystems, but impacts on herbaceous communities are poorly understood. We compared herbaceous plant community abundance, diversity and composition in RMZs along small streams in northern Minnesota, USA, among four treatments before...

  2. The Forecasting of Adaptation Potential of Herbaceous Perennials

    Directory of Open Access Journals (Sweden)

    Belykh, O. A.

    2013-04-01

    Full Text Available This work investigates the problem of the ecobiomorph productive features formation of perennial herbs Ranunculaceae family forecasting on the basis of quantitative connections of species parameters with the leading geomorphological factors of South Siberia environment.

  3. Influence of primitive Biłgoraj horses on the glossy buckthorn (Frangula alnus)-dominated understory in a mixed coniferous forest

    Science.gov (United States)

    Klich, Daniel

    2018-02-01

    Changes in the understory dominated by glossy buckthorn Frangula alnus via the influence of primitive horses were analyzed in a 28-year-old enclosure in the village of Szklarnia at the Biłgoraj Horse-Breeding Centre near Janów Lubelski (eastern Poland). The analysis was conducted in 20 circular plots (30 m2) defined in adjacent, similar forest stands (enclosed and control). Disturbance by the horses, mainly through trampling, caused numerous paths to form within the glossy buckthorn-dominated understory and led to a decrease in density of stems of lower height classes (30-80 and 81-130 cm, respectively). An increase in species diversity at the expense of glossy buckthorn density was also observed. The horses' trampling caused an increase in Padus avium density and the encroachment of other woody plant species that were less shade-tolerant and grew well in soils rich in nutrients. An increase in the density of woody plants over 180 cm above ground was observed within the enclosure, which was probably the result of the horses' excretion of feces. The results presented here provide new insight into the ecological role that horses play in forest-meadow landscape mosaics, which, via altering the development of vegetation, may contribute to an increase in biodiversity within forest habitats.

  4. Diversity and distribution patterns of root-associated fungi on herbaceous plants in alpine meadows of southwestern China.

    Science.gov (United States)

    Gao, Qian; Yang, Zhu L

    2016-01-01

    The diversity of root-associated fungi associated with four ectomycorrhizal herbaceous species, Kobresia capillifolia, Carex parva, Polygonum macrophyllum and Potentilla fallens, collected in three sites of alpine meadows in southwestern China, was estimated based on internal transcribed spacer (ITS) rDNA sequence analysis of root tips. Three hundred seventy-seven fungal sequences sorted to 154 operational taxonomical units (sequence similarity of ≥ 97% across the ITS) were obtained from the four plant species across all three sites. Similar taxa (in GenBank with ≥ 97% similarity) were not found in GenBank and/or UNITE for most of the OTUs. Ectomycorrhiz a made up 64% of the fungi operational taxonomic units (OTUs), endophytes constituted 4% and the other 33% were unidentified root-associated fungi. Fungal OTUs were represented by 57% basidiomycetes and 43% ascomycetes. Inocybe, Tomentella/Thelophora, Sebacina, Hebeloma, Pezizomycotina, Cenococcum geophilum complex, Cortinarius, Lactarius and Helotiales were OTU-rich fungal lineages. Across the sites and host species the root-associated fungal communities generally exhibited low host and site specificity but high host and sampling site preference. Collectively our study revealed noteworthy diversity and endemism of root-associated fungi of alpine plants in this global biodiversity hotspot. © 2016 by The Mycological Society of America.

  5. DIATOMS AS INDICATORS OF ISOLATED HERBACEOUS WETLAND CONDITION IN FLORIDA, USA

    Science.gov (United States)

    Benthic, epiphytic, and phytoplanktonic diatoms, as well as soil and water physical-chemical parameters, were sampled from 70 small (~1 ha) isolated depressional herbaceous wetlands located along a gradient of human disturbance in peninsular Florida to: 1) compare assemblage str...

  6. Evaluating subsoiling and herbaceous weed control on shortleaf pine planted in retired farm land

    Science.gov (United States)

    John D. Kushla

    2010-01-01

    In March 2005, shortleaf pine was planted on retired fields of the Mississippi Agriculture and Forestry Experiment Station in Holly Springs. The objectives were to evaluate subsoiling and herbaceous weed control on first year seedling stocking, survival, and size. First year seedling measurements were made on stocking, survival, and size. Only results for first year...

  7. Changes in Patterns of Understory Leaf Phenology and Herbivory following Hurricane Damage.

    Science.gov (United States)

    Pilar Angulo-Sandoval; H. Fernandez-Marin; J. K. Zimmerman; T. M. Aide

    2004-01-01

    Hurricanes are important disturbance events in many forested ecosystems. They can have strong effects on both forest structure and animal populations, and yet few studies have considered the impacts on plant–animal interactions. Reduction of canopy cover by severe winds increases light availability to understory plants, providing an opportunity for increased growth. An...

  8. Responses of Soil Organic Carbon to Long-Term Understory Removal in Subtropical Cinnamomum camphora Stands

    Directory of Open Access Journals (Sweden)

    Yacong Wu

    2014-01-01

    Full Text Available We conducted a study on a 48-year-old Cinnamomum camphora plantation in the subtropics of China, by removing understory gradually and then comparing this treatment with a control (undisturbed. This study analyzed the content and storage soil organic carbon (SOC in a soil depth of 0–60 cm. The results showed that SOC content was lower in understory removal (UR treatment, with a decrease range from 5% to 34%, and a decline of 10.16 g·kg−1 and 8.58 g·kg−1 was noticed in 0–10 cm and 10–20 cm layers, respectively, with significant differences (P<0.05. Carbon storage was reduced in UR, ranging from 2% to 43%, with a particular drastic decline of 15.39 t·hm−2 and 11.58 t·hm−2 in 0–10 cm (P<0.01 and 10–20 cm (P<0.01 layers, respectively. Content of SOC had an extremely significant (P<0.01 correlation with soil nutrients in the two stands, and the correlation coefficients of CK were higher than those of UR. Our data showed that the presence of understory favored the accumulation of soil organic carbon to a large extent. Therefore, long-term practice of understory removal weakens the function of forest ecosystem as a carbon sink.

  9. Effect of understory management on phenological responses of eastern black walnut on an alluvial Arkansas soil

    Science.gov (United States)

    Black walnut (Juglans nigra L.) is commonly grown in agroforestry practices for nuts and/or timber with little knowledge of how understory herbage management might affect tree phenology. We compared black walnut plant type (variety and wild-type) for phenological response in date of budburst, leaf ...

  10. Western dwarf mistletoe infects understory Jeffrey pine seedlings on Cleveland National Forest, California

    Science.gov (United States)

    Robert F. Scharpf; Detlev Vogler

    1986-01-01

    Many young, understory Jeffrey pines (Pinus jeffreyi Grev. & Balf.) were found to be infected by western dwarf mistletoe (Arceuthobium campylopodum Engelm.) on Laguna Mountain, Cleveland National Forest, in southern California. Under heavily infected overstory, about three-fourths of the young pines (about 15 years old on the...

  11. Infrared heater system for warming tropical forest understory plants and soils

    Science.gov (United States)

    Bruce A. Kimball; Aura M. Alonso-Rodríguez; Molly A. Cavaleri; Sasha C. Reed; Grizelle González; Tana E. Wood

    2018-01-01

    The response of tropical forests to global warming is one of the largest uncertainties in predicting the future carbon balance of Earth. To determine the likely effects of elevated temperatures on tropical forest understory plants and soils, as well as other ecosystems, an infrared (IR) heater system was developed to provide in situ warming for the Tropical Responses...

  12. Maintenance of a living understory enhances soil carbon sequestration in subtropical orchards.

    Science.gov (United States)

    Liu, Zhanfeng; Lin, Yongbiao; Lu, Hongfang; Ding, Mingmao; Tan, Yaowen; Xu, Shejin; Fu, Shenglei

    2013-01-01

    Orchard understory represents an important component of the orchards, performing numerous functions related to soil quality, water relations and microclimate, but little attention has been paid on its effect on soil C sequestration. In the face of global climate change, fruit producers also require techniques that increase carbon (C) sequestration in a cost-effective manner. Here we present a case study to compare the effects of understory management (sod culture vs. clean tillage) on soil C sequestration in four subtropical orchards. The results of a 10-year study indicated that the maintenance of sod significantly enhanced the soil C stock in the top 1 m of orchard soils. Relative to clean tillage, sod culture increased annual soil C sequestration by 2.85 t C ha(-1), suggesting that understory management based on sod culture offers promising potential for soil carbon sequestration. Considering that China has the largest area of orchards in the world and that few of these orchards currently have sod understories, the establishment and maintenance of sod in orchards can help China increase C sequestration and greatly contribute to achieving CO2 reduction targets at a regional scale and potentially at a national scale.

  13. Eleventh-year response of loblolly pine and competing vegetation to woody and herbaceous plant control on a Georgia flatwoods site

    Science.gov (United States)

    Bruce R. Zutter; James H. Miller

    1998-01-01

    Through 11 growing seasons, growth of loblolly pine (Pinus taeda L.) increased after control of herbaceous, woody, or both herbaceous and woody vegetation (total control) for the first 3 years after planting on a bedded site in the Georgia coastal flatwoods. Gains in stand volume index from controlling either herbaceous or woody vegetation alone were approximately two-...

  14. Grass species selection patterns on rotationally-grazed Dohne ...

    African Journals Online (AJOL)

    Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally-grazed Dohne Sourveld, at four different stocking rates. Reports on species selection by cattle and sheep grazing together. Illustrates with graphsLanguage: English. Keywords: Grass species; Herbage availibility; ...

  15. Comparison of radiocesium concentration changes in leguminous and non-leguminous herbaceous plants observed after the Fukushima Dai-ichi Nuclear Power Plant accident.

    Science.gov (United States)

    Uchida, Shigeo; Tagami, Keiko

    2018-06-01

    Transfer of radiocesium from soil to crops is an important pathway for human intake. In the period from one to two years after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, food monitoring results showed that radiocesium concentrations in soybean (a legume) were higher than those in other annual agricultural crops; in these crops, root uptake is the major pathway of radiocesium from soil to plant. However, it was not clear whether or not leguminous and non-leguminous herbaceous plants have different Cs uptake abilities from the same soil because crop sample collection fields were different. In this study, therefore, we compared the concentrations of 137 Cs in seven herbaceous plant species including two leguminous plants (Trifolium pratense L. and Vicia sativa L.) collected in 2012-2016 from the same sampling field in Chiba, Japan that had been affected by the FDNPP accident fallout. Among these species, Petasites japonicus (Siebold & Zucc.) Maxim. showed the highest 137 Cs concentration in 2012-2016. The correlation factor between all concentration data for 137 Cs and those for 40 K in these seven plants was R = 0.54 (p plants did not differ significantly, but 137 Cs data in the Poaceae family plants were significantly lower than those in T. pratense (p plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Abiotic and herbaceous vegetational characteristics of an arid ...

    African Journals Online (AJOL)

    Clipped material was separated by species and classified dead or live by physical examination. A 5cm diameter metal soil corer was used to sample belowground plant material, at monthly intervals. The sampled material was washed with running water over 2mm sieves and classified dead or live using the vital staining ...

  17. Management of Herbaceous Seeps and Wet Savannas for Threatened and Endangered Species.

    Science.gov (United States)

    1998-04-01

    in Louisiana bogs were those tolerant of wet habitat: wax myrtle (Myrica cerifera), red-bay ( Persea borbonia), red choke-berry (Aronia arbutifolia...mixed pine-hardwood forests, and in ecotones between forest types. Birds Southeastern American Kestrel Falco sparverius paulus SAR Found in open...indigo snakes (USFWS 1982); and development of unsuitable foraging habitat for southeastern American kestrels (Falco sparverius paulus) (Bohall 1984

  18. Effects of grazing and fire on herbaceous species in the Bolivian Altiplano

    OpenAIRE

    Aguilar, Lita Beatriz Patty

    2012-01-01

    High mountain rangelands had been under human land use for millennia in most parts of the world. Traditional land care systems led to highly diverse and stable ecosystems. As these traditions fade and population pressure rises, these grassland systems become overgrazed, lose carrying capacity and biodiversity and become eroded. Semi-arid high elevation pastures in tropical and subtropical regions are particularly endangered. This PhD project aimed at assessing the plant invento...

  19. Leaching of Alkalis in Biomass Using Banagrass as a Prototype Herbaceous Species: Final Report, February 1997

    Energy Technology Data Exchange (ETDEWEB)

    Turn, S.; Kinoshita, C.; Ishimura, D.; Jenkins, B. M.; Zhou, J.

    1997-02-01

    Feasibility study for growing biomass crops on reclaimed phosphate mining land and producing ethanol from them proposes a combination of sugarcane and cellulosic crops with both conventional sugar and cellulosic ethanol production facilities.

  20. Negative Plant-Soil Feedback and Positive Species Interaction in a Herbaceous Plant Community

    NARCIS (Netherlands)

    Bonanomi, G.; Rietkerk, M.; Dekker, S.C.; Mazzoleni, S.

    2005-01-01

    Increasing evidence shows that facilitative interaction and negative plant¿soil feedback are driving factors of plant population dynamics and community processes. We studied the intensity and the relative impact of negative feedback on clonal growth and seed germination of Scirpus holoschoenus, a

  1. Negative Plant–Soil Feedback and Positive Species Interaction in a Herbaceous Plant Community

    NARCIS (Netherlands)

    Bonanomi, G.; Rietkerk, M.G.; Dekker, S.C.; Mazzoleni, S.

    2005-01-01

    Increasing evidence shows that facilitative interaction and negative plant–soil feedback are driving factors of plant population dynamics and community processes. We studied the intensity and the relative impact of negative feedback on clonal growth and seed germination of Scirpus holoschoenus, a

  2. FROM ANTHESIS TO DIASPORE DISPERSAL: REPRODUCTIVE MECHANISMS OF RARE HERBACEOUS MORACEAE SPECIES ENDEMIC TO BRAZIL

    Directory of Open Access Journals (Sweden)

    Luzia Márcia de Araújo

    2017-01-01

    Full Text Available Los estudios sobre la biología reproductiva de las especies de Dorstenia son escasos. En este artículo analizamos la sexualidad, la biología floral y dispersión de las diásporas de Dorstenia arifolia y D. bonijesu, incluyendo sus sistemas reproductivos y polinizadores, en poblaciones naturales localizadas en el estado de Minas Gerais, sudeste de Brasil. Registramos, por primera vez, la presencia de cenantos unisexuales (masculinos y bisexuales en un mismo individuo de Dorstenia arifolia; en cambio, sólo se observaron cenantos bisexuales en D. bonijesu. En ambas especies los cenantos fueron de larga duración, y los cenantos bisexuales exhibieron protoginia. Registramos autocompatibilidad y miofilia en Dorstenia arifolia, que fue polinizada por pequeñas moscas de la familia Lauxaniidae. Estos insectos no solo usan el polen como alimento sino que utilizan el cenanto como sitio de oviposición, siendo este un hecho registrado por primera vez para para las especies estudiadas. Dorstenia bonijesu, aún sin visitantes florales, también produce semillas mediante apomixis, un nuevo sistema reproductivo para el género. Las dos especies estudiadas son autocóricas; sin embargo, Dorstenia bonijesu exhibió un tipo peculiar de hidrocoria. Las novedades aquí registradas indican la necesidad de estudios adicionales para mejorar la comprensión de los atributos reproductivos de las especies de Dorstenia.

  3. Effects of the interception of litterfall by the understory on carbon cycling in eucalyptus plantations of South China.

    Science.gov (United States)

    Yang, Long; Wang, Jun; Huang, Yuhui; Hui, Dafeng; Wen, Meili

    2014-01-01

    For the purposes of forest restoration, carbon (C) fixation, and economic improvement, eucalyptus (Eucalyptus urophylla) has been widely planted in South China. The understory of eucalyptus plantations is often occupied by a dense community of the fern Dicranopteris dichotoma, which intercepts tree canopy leaf litter before it reaches the ground. To understand the effects of this interception of litterfall on C cycling in eucalyptus plantations, we quantified the mass of intercepted litter and the influences of litterfall interception on litter decomposition and soil respiration. The total mass of E. urophylla litterfall collected on the understory was similar to that collected by the traditional litter trap method. All of the eucalyptus litterfall is intercepted by the D. dichotoma canopy. Of the litterfall that was intercepted by D. dichotoma, 20-40% and 60-80% was intercepted by the top (50-100 cm) and bottom (0-50 cm) of the understory canopy, respectively. Intercepted litterfall decomposed faster at the bottom of understory canopy (at the base of the plants) than at the top, and decomposition was slower on the soil surface in the absence of understory than on any location in the understory canopy. Soil respiration was highest when both the understory and litter were present and was lowest when both the understory and litter were absent. These results indicate that litterfall interception changed carbon flow between aboveground and belowground through litter decomposition and soil respiration, which changed carbon cycling in eucalyptus plantations. The effects of the understory on litter decomposition and soil respiration should be considered in ecosystem carbon models.

  4. Effects of the interception of litterfall by the understory on carbon cycling in eucalyptus plantations of South China.

    Directory of Open Access Journals (Sweden)

    Long Yang

    Full Text Available For the purposes of forest restoration, carbon (C fixation, and economic improvement, eucalyptus (Eucalyptus urophylla has been widely planted in South China. The understory of eucalyptus plantations is often occupied by a dense community of the fern Dicranopteris dichotoma, which intercepts tree canopy leaf litter before it reaches the ground. To understand the effects of this interception of litterfall on C cycling in eucalyptus plantations, we quantified the mass of intercepted litter and the influences of litterfall interception on litter decomposition and soil respiration. The total mass of E. urophylla litterfall collected on the understory was similar to that collected by the traditional litter trap method. All of the eucalyptus litterfall is intercepted by the D. dichotoma canopy. Of the litterfall that was intercepted by D. dichotoma, 20-40% and 60-80% was intercepted by the top (50-100 cm and bottom (0-50 cm of the understory canopy, respectively. Intercepted litterfall decomposed faster at the bottom of understory canopy (at the base of the plants than at the top, and decomposition was slower on the soil surface in the absence of understory than on any location in the understory canopy. Soil respiration was highest when both the understory and litter were present and was lowest when both the understory and litter were absent. These results indicate that litterfall interception changed carbon flow between aboveground and belowground through litter decomposition and soil respiration, which changed carbon cycling in eucalyptus plantations. The effects of the understory on litter decomposition and soil respiration should be considered in ecosystem carbon models.

  5. SIMULATING VARIOUS TERRESTRIAL AND UAV LIDAR SCANNING CONFIGURATIONS FOR UNDERSTORY FOREST STRUCTURE MODELLING

    Directory of Open Access Journals (Sweden)

    M. Hämmerle

    2017-09-01

    Full Text Available Information about the 3D structure of understory vegetation is of high relevance in forestry research and management (e.g., for complete biomass estimations. However, it has been hardly investigated systematically with state-of-the-art methods such as static terrestrial laser scanning (TLS or laser scanning from unmanned aerial vehicle platforms (ULS. A prominent challenge for scanning forests is posed by occlusion, calling for proper TLS scan position or ULS flight line configurations in order to achieve an accurate representation of understory vegetation. The aim of our study is to examine the effect of TLS or ULS scanning strategies on (1 the height of individual understory trees and (2 understory canopy height raster models. We simulate full-waveform TLS and ULS point clouds of a virtual forest plot captured from various combinations of max. 12 TLS scan positions or 3 ULS flight lines. The accuracy of the respective datasets is evaluated with reference values given by the virtually scanned 3D triangle mesh tree models. TLS tree height underestimations range up to 1.84 m (15.30 % of tree height for single TLS scan positions, but combining three scan positions reduces the underestimation to maximum 0.31 m (2.41 %. Combining ULS flight lines also results in improved tree height representation, with a maximum underestimation of 0.24 m (2.15 %. The presented simulation approach offers a complementary source of information for efficient planning of field campaigns aiming at understory vegetation modelling.

  6. Simulating Various Terrestrial and Uav LIDAR Scanning Configurations for Understory Forest Structure Modelling

    Science.gov (United States)

    Hämmerle, M.; Lukač, N.; Chen, K.-C.; Koma, Zs.; Wang, C.-K.; Anders, K.; Höfle, B.

    2017-09-01

    Information about the 3D structure of understory vegetation is of high relevance in forestry research and management (e.g., for complete biomass estimations). However, it has been hardly investigated systematically with state-of-the-art methods such as static terrestrial laser scanning (TLS) or laser scanning from unmanned aerial vehicle platforms (ULS). A prominent challenge for scanning forests is posed by occlusion, calling for proper TLS scan position or ULS flight line configurations in order to achieve an accurate representation of understory vegetation. The aim of our study is to examine the effect of TLS or ULS scanning strategies on (1) the height of individual understory trees and (2) understory canopy height raster models. We simulate full-waveform TLS and ULS point clouds of a virtual forest plot captured from various combinations of max. 12 TLS scan positions or 3 ULS flight lines. The accuracy of the respective datasets is evaluated with reference values given by the virtually scanned 3D triangle mesh tree models. TLS tree height underestimations range up to 1.84 m (15.30 % of tree height) for single TLS scan positions, but combining three scan positions reduces the underestimation to maximum 0.31 m (2.41 %). Combining ULS flight lines also results in improved tree height representation, with a maximum underestimation of 0.24 m (2.15 %). The presented simulation approach offers a complementary source of information for efficient planning of field campaigns aiming at understory vegetation modelling.

  7. Spatial and temporal variability of canopy cover and understory light in a Cerrado of Southern Brazil

    Directory of Open Access Journals (Sweden)

    JP. Lemos-Filho

    Full Text Available Canopy cover has significant effects on the understory environment, including upon light availability for seedling growth. The aim of the present study was to verify spatial heterogeneity and seasonal changes in the canopy cover of a dense Cerrado area, and their relationship to understory photosynthetic active radiation availability. Leaf area index (LAI values in the rainy season varied from 0.9 to 4.83, with 40% of the values ranging from 4.0 to 5.0, while in the dry season LAI varied from 0.74 to 3.3, with 53% of the values oscilating from 2.0 to 3.0. Understory light (Qi and the Lambert-Beer ratio (Qi/Qo were taken around noon on sunny days (between 11:00 AM and 1:00 PM. They were also statistically different (p < 0.01 between the dry and wet seasons, with 72% of sampled points in the rainy season presenting photosynthetic photon flux density (PPFD values lower than 250 μmol.m-2/s around noon, whereas in the dry season, most PPFD values varied from 1500 to 1817 μmol.m-2/s , thus providing high light availability for understory plants. In most of the studied sites, understory plants did not even receive enough light for 50% of their photosynthetic capacity in the wet season. In contrast during the dry season, Qi/Qo values of 0.8 to 1.0 were observed in more than 50% of the points, thereby allowing for photosynthetic light saturation. Thus, light variability around noon was higher during the dry season than in the wet season, its heterogeneity being related to spatial complexity in the canopy cover.

  8. Distribution model of understory vegetation in beech forests from Central Apennines (Italy in relation to edaphic parameters

    Directory of Open Access Journals (Sweden)

    De Nicola C

    2007-12-01

    Full Text Available The first results of a study of monitoring species and habitats in the framework of the Life 04NAT/IT/000190 "Tutela dei siti Natura 2000 gestiti dal Corpo Forestale dello Stato" are presented. This study was carried out by the Department of Plant Biology of the University of Rome (La Sapienza and the National Forest Service. We focused the investigation on the relationships between herbaceous species and pedological parameters (humus and soil in Central-Apennine beech forests. Data have been collected through 40 phytosociological relevés, 15 soil profiles and 40 humus profiles in 40 forest plots, between March 2005 and September 2006. In this paper we presented data elaborated on a subset of 15 plots where soil profiles were available. The species of undergrowth showed different ecological requirements to some edaphic and humus parameters (pH, sand, loam, clay, organic matter, nitrogen, carbon/nitrogen ratio, Ca++, K+;thickness and carbon content of the organic layers: significant correlations have been found using Pearson correlation test. The multiple regression analysis allowed to identify the factors more influencing the species distribution: thickness of the organic layers, carbon content (% C and carbon/nitrogen ratio (C/N. Basing on the thickness of humus horizons (OL, OF, OH, and on carbon content, two species groups with different ecology have been recognized: (a nemoral species typical of shady beech stands on oligomull/dysmull/thin amphimull (0 < 1cm.; 5.7 < %C < 9.9; (b heliophilous species of more xeric stands on thick amphimull (1.25 < 11.5 cm.; 9.9 < %C < 13.7. The relationships among species and soil parameters and humus forms allow to recognize small differences within a homogeneous habitat and therefore they can provide management indications also at micro-scale level.

  9. Effects of understory vegetation and litter on plant nitrogen (N, phosphorus (P, N:P ratio and their relationships with growth rate of indigenous seedlings in subtropical plantations.

    Directory of Open Access Journals (Sweden)

    Jun Wang

    Full Text Available Establishing seedlings in subtropical plantations is very important for forest health, succession and management. Information on seedling nutrient concentrations is essential for both the selection of suitable indigenous tree species to accelerate succession of the established plantation and sustainable forest management. In this study, we investigated the concentrations of nitrogen ([N], phosphorus ([P], and N:P ratio in leaves, stems and roots of seedlings of three indigenous tree species (Castanopsis chinensis, Michelia chapensis and Psychotria rubra transplanted with removing or retaining understory vegetation and litter at two typical subtropical forest plantations (Eucalyptus plantation and native species plantation. We also measured the relative growth rate (RGR of seedling height, and developed the relationships between RGR and leaf [N], [P] and N:P ratio. Results showed that treatments of understory vegetation and associated litter (i.e. removal or retained generally had no significant effects on leaf [N], [P], N:P ratio and RGR of the transplanted tree seedlings for the experimental period. But among different species, there were significant differences in nutrient concentrations. M. chapensis and P. rubra had higher [N] and [P] compared to C. chinensis. [N] and [P] also varied among different plant tissues with much higher values in leaves than in roots for all indigenous species. RGR of indigenous tree seedlings was mostly positively correlated with leaf [N] and [P], but negatively correlated with leaf N:P ratio. Considering the low [P] and high N:P ratio observed in the introduced indigenous tree seedlings, we propose that the current experimental plantations might be P limited for plant growth.

  10. Role of the Qinghai-Tibetan Plateau uplift in the Northern Hemisphere disjunction: evidence from two herbaceous genera of Rubiaceae.

    Science.gov (United States)

    Deng, Tao; Zhang, Jian-Wen; Meng, Ying; Volis, Sergei; Sun, Hang; Nie, Ze-Long

    2017-10-17

    To assess the role of the Qinghai-Tibetan Plateau uplift in shaping the intercontinental disjunction in Northern Hemisphere, we analyzed the origin and diversification within a geological timeframe for two relict herbaceous genera, Theligonum and Kelloggia (Rubiaceae). Phylogenetic relationships within and between Theligonum and Kelloggia as well as their relatives were inferred using five chloroplast markers with parsimony, Bayesian and maximum-likelihood approaches. Migration routes and evolution of these taxa were reconstructed using Bayesian relaxed molecular clock and ancestral area reconstruction. Our results suggest the monophyly of each Theligonum and Kelloggia. Eastern Asian and North American species of Kelloggia diverged at ca.18.52 Mya and the Mediterranean species of Theligonum diverged from eastern Asian taxa at ca.13.73 Mya. Both Kelloggia and Theligonum are Tethyan flora relicts, and their ancestors might have been occurred in warm tropical to subtropical environments along the Tethys coast. The Qinghai-Tibetan Plateau separated the eastern and western Tethyan area may contribute significantly to the disjunct distributions of Theligonum, and the North Atlantic migration appears to be the most likely pathway of expansion of Kelloggia to North America. Our results highlight the importance role of the QTP uplift together with corresponding geological and climatic events in shaping biodiversity and biogeographic distribution in the Northern Hemisphere.

  11. Role of burning season on initial understory vegetation response to prescribed fire in a mixed conifer forest

    Science.gov (United States)

    Knapp, E.E.; Schwilk, D.W.; Kane, J.M.; Keeley, J.E.

    2007-01-01

    Although the majority of fires in the western United States historically occurred during the late summer or early fall when fuels were dry and plants were dormant or nearly so, early-season prescribed burns are often ignited when fuels are still moist and plants are actively growing. The purpose of this study was to determine if burn season influences postfire vegetation recovery. Replicated early-season burn, late-season burn, and unburned control units were established in a mixed conifer forest, and understory vegetation was evaluated before and after treatment. Vegetation generally recovered rapidly after prescribed burning. However, late-season burns resulted in a temporary but significant drop in cover and a decline in species richness at the 1 m 2 scale in the following year. For two of the several taxa that were negatively affected by burning, the reduction in frequency was greater after late-season than early-season burns. Early-season burns may have moderated the effect of fire by consuming less fuel and lessening the amount of soil heating. Our results suggest that, when burned under high fuel loading conditions, many plant species respond more strongly to differences in fire intensity and severity than to timing of the burn relative to stage of plant growth. ?? 2007 NRC.

  12. Detection of herbaceous-plant pararetrovirus in lichen herbarium samples.

    Science.gov (United States)

    Petrzik, K; Koloniuk, I; Sarkisová, T; Číhal, L

    2016-06-01

    Cauliflower mosaic virus (CaMV) - a plant pararetrovirus that naturally causes diseases in Brassicaceae and Solanaceae plant hosts worldwide - has been detected by PCR for the first time in herbarium samples of Usnea sp. lichens. The virus's presence in these lichens did not result in any micro- or macromorphological changes, and the herbarium records were classified as representative for the distinct species. Sequence analyses classified all the detected viruses into one lineage of CaMV isolates. We have shown here that herbarium samples could be a good source for virus study, especially where a longer time span is involved.

  13. Soil compaction related to grazing and its effects on herbaceous roots frequency and soil organic matter content in rangelands of SW Spain

    Science.gov (United States)

    Pulido, Manuel; Schnabel, Susanne; Francisco Lavado Contador, Joaquín; Miralles Mellado, Isabel

    2016-04-01

    Rangelands in SW Spain occupy a total surface area of approximately 6 million ha and constitute the most representative extensive ranching system of the Iberian Peninsula gathering more than 13 million livestock heads. They are characterised by an herbaceous layer, mostly composed of therophytic species, with a disperse tree cover, mainly holm oak and cork oak (Quercus ilex rotundifolia and Q. suber), interspersed with shrubs in many places. This type of land system is of ancient origin and experienced frequent changes in land use in the past, since agricultural, livestock and forestry activities have coexisted within the same farms. In recent decades, livestock farming has become dominant due, in part, to the subsidies of the Common Agriculture Policy. Since Spain joined the European Union in 1986 until the year 2000, the number of domestic animals doubled, particularly cattle, and consequently animal stocking rates have increased on average from 0.40 AU ha-1 up to 0.70 AU ha-1. This increase in animal stocking rates, along with a progressive substitution of cattle instead of sheep in many farms, has led to the occurrence of land degradation processes such as the reduction of grass cover or soil compaction in heavily grazed areas. Previous research has evidenced higher values of soil bulk density and resistance to penetration as well as larger bare surface areas in spring in fenced areas with animal stocking rates above 1 AU ha-1. However, a better understanding of how increasing bulk density or resistance to penetration influence the frequency of herbaceous roots and how a reduction in the frequency of roots affects soil organic matter content in rangelands is still unknown. Therefore, the main goal of this study was to determine possible relationships between the frequencies of herbaceous roots and soil organic matter content in order to understand the effect of excessive animal numbers on the depletion of soil fertility by reducing progressively the quantity of

  14. Grassland and forest understory biomass emissions from prescribed fires in the southeastern United States – RxCADRE 2012

    Science.gov (United States)

    Smoke measurements were made during grass and forest understory prescribed fires as part of a comprehensive program to understand fire and smoke behaviour. Instruments deployed on the ground, airplane and tethered aerostat platforms characterized the smoke plumes through measure...

  15. Refugial persistence and postglacial recolonization of North America by the cold-tolerant herbaceous plant Orthilia secunda.

    Science.gov (United States)

    Beatty, Gemma E; Provan, Jim

    2010-11-01

    Previous phylogeographical and palaeontological studies on the biota of northern North America have revealed a complex scenario of glacial survival in multiple refugia and differing patterns of postglacial recolonization. Many putative refugial regions have been proposed both north and south of the ice sheets for species during the Last Glacial Maximum, but the locations of many of these refugia remain a topic of great debate. In this study, we used a phylogeographical approach to elucidate the refugial and recolonization history of the herbaceous plant species Orthilia secunda in North America, which is found in disjunct areas in the west and east of the continent, most of which were either glaciated or lay close to the limits of the ice sheets. Analysis of 596 bp of the chloroplast trnS-trnG intergenic spacer and five microsatellite loci in 84 populations spanning the species' range in North America suggests that O. secunda persisted through the Last Glacial Maximum (LGM) in western refugia, even though palaeodistribution modelling indicated a suitable climate envelope across the entire south of the continent. The present distribution of the species has resulted from recolonization from refugia north and south of the ice sheets, most likely in Beringia or coastal regions of Alaska and British Columbia, the Washington/Oregon region in the northwest USA, and possibly from the region associated with the putative 'ice-free corridor' between the Laurentide and Cordilleran ice sheets. Our findings also highlight the importance of the Pacific Northwest as an important centre of intraspecific genetic diversity, owing to a combination of refugial persistence in the area and recolonization from other refugia. © 2010 Blackwell Publishing Ltd.

  16. Thermogravimetry/mass spectrometry study of woody residues and an herbaceous biomass crop using PCA techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, C.J.; Velo, E.; Puigjaner, L. [Department of Chemical Engineering, ETSEIB, Universitat Politecnica de Catalunya, Avinguda Diagonal 647, G2, E-08028 Barcelona (Spain); Meszaros, E.; Jakab, E. [Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences, P.O. Box 17, Budapest 1525 (Hungary)

    2007-10-15

    The devolatilization behaviour of pine and beech wood from carpentry residuals and an herbaceous product from an energy plantation (artichoke thistle) was investigated by thermogravimetry/mass spectrometry (TG/MS). The effect of three pre-treatments, hot-water washing, ethanol extraction and their combination, was also studied. Principal component analysis (PCA) was employed to help in the evaluation of the large data set of results. The characteristics of the thermal decomposition of the herbaceous crop are considerably different from that of the woody biomass samples. The evolution profiles of some characteristic pyrolysis products revealed that the thermal behaviour of wood and thistle is still considerably different after the elimination of some of the inorganic ions and extractive compounds, although the macromolecular components of the samples decompose at similar temperatures. With the help of the PCA calculations, the effect of the different pre-treatments on the production of the main pyrolysis products was evidenced. (author)

  17. Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis

    Science.gov (United States)

    Laughlin, D.C.; Abella, S.R.; Covington, W.W.; Grace, J.B.

    2007-01-01

    Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive effect of richness on plant cover. Richness was strongly related to soil nitrogen in the model, with evidence for both a direct negative effect and an indirect non-linear relationship mediated through understory plant cover. Soil organic matter appeared to have a positive influence on understory richness that was independent of soil nitrogen. Richness was lowest where the forest overstory was densest, which can be explained through indirect effects on soil organic matter, soil nitrogen and understory cover. Finally, model results suggest a variety of direct and indirect processes whereby mineral soil properties can influence richness. Conclusions: Understory plant species richness and plant cover in P. ponderosa forests appear to be significantly influenced by soil organic matter and nitrogen, which are, in turn, related to overstory density and composition and mineral soil properties. Thus, soil properties can impose direct and indirect constraints on local species diversity in ponderosa pine forests. ?? IAVS; Opulus Press.

  18. Evaluation quantitative et qualitative de la strate herbacée du ...

    African Journals Online (AJOL)

    Cette étude s'insère dans le cadre de la compréhension de l'apport de la strate herbacée dans une formation de Quercus rotundifolia L. utilisée par un cheptel dont l'importance socio-économique pour la population est vitale. Le défrichement, moyen pratique d'accroître la production fourragère en milieu forestier, est ...

  19. 127 Evaluation quantitative et qualitative de la strate herbacée du ...

    African Journals Online (AJOL)

    utilsateur

    Résumé. Cette étude s'insère dans le cadre de la compréhension de l'apport de la strate herbacée dans une formation de Quercus rotundifolia L. utilisée par un cheptel dont l'importance socio-économique pour la population est vitale. Le défrichement, moyen pratique d'accroître la production fourragère en milieu forestier ...

  20. Use of Plant Growth Regulators to Improve Branching of Herbaceous Perennial Liners

    OpenAIRE

    Grossman, Mara Celeste

    2012-01-01

    The objective of this study is to evaluate the efficacy of PGRs to improve branching during production of herbaceous perennial liners and finished plants. The effects of benzyladenine (BA) on the branching and root and shoot growth of Agastache Clayt. Ex Gronov. 'Purple Hazeâ , Gaura lindheimeri Engelm. & A. Gray 'Siskiyou Pink', Lavandula à intermedia Emeric ex Loisel. 'Provence', Leucanthemum à superbum (Bergmans ex J.W. Ingram) Bergmans ex Kent. 'Snowcap', and Salvia à sylv...

  1. The rise of angiosperm-dominated herbaceous floras: Insights from Ranunculaceae

    OpenAIRE

    Wei Wang; Li Lin; Xiao-Guo Xiang; Rosa del C. Ortiz; Yang Liu; Kun-Li Xiang; Sheng-Xiang Yu; Yao-Wu Xing; Zhi-Duan Chen

    2016-01-01

    The rise of angiosperms has been regarded as a trigger for the Cretaceous revolution of terrestrial ecosystems. However, the timeframe of the rise angiosperm-dominated herbaceous floras (ADHFs) is lacking. Here, we used the buttercup family (Ranunculaceae) as a proxy to provide insights into the rise of ADHFs. An integration of phylogenetic, molecular dating, ancestral state inferring, and diversification analytical methods was used to infer the early evolutionary history of Ranunculaceae. We...

  2. Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland.

    Directory of Open Access Journals (Sweden)

    Erica N Spotswood

    Full Text Available Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species, temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

  3. Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland.

    Science.gov (United States)

    Spotswood, Erica N; Bartolome, James W; Allen-Diaz, Barbara

    2015-01-01

    Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species), temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

  4. Responses of southeast Alaska understory species to variation in light and soil environments

    Science.gov (United States)

    Thomas A. Hanley; Bernard T. Bormann; Jeffrey C. Barnard; S. Mark Nay

    2014-01-01

    Aboveground growth rates of seedlings of bunchberry (Cornus canadensis L.), oval-leaf blueberry (Vaccinium ovalifolium Sm.), salmonberry (Rubus spectabilis Pursh), devilsclub (Oplopanax horridus (Sm.) Miq.), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) were...

  5. A Phenology-Based Method for Monitoring Woody and Herbaceous Vegetation in Mediterranean Forests from NDVI Time Series

    OpenAIRE

    David Helman; Itamar M. Lensky; Naama Tessler; Yagil Osem

    2015-01-01

    We present an efficient method for monitoring woody (i.e., evergreen) and herbaceous (i.e., ephemeral) vegetation in Mediterranean forests at a sub pixel scale from Normalized Difference Vegetation Index (NDVI) time series derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). The method is based on the distinct development periods of those vegetation components. In the dry season, herbaceous vegetation is absent or completely dry in Mediterranean forests. Thus the mean NDVI ...

  6. Groundwater uptake by forest and herbaceous vegetation in the context of salt accumulation in the Hungarian Great Plain

    Science.gov (United States)

    Gribovszki, Zoltán; Kalicz, Péter; Balog, Kitti; Szabó, András; Fodor, Nándor; Tóth, Tibor

    2013-04-01

    In Hungarian Great Plain forested areas has significantly increased during the last century. Hydrological effects of trees differ from that of crops or grasses in that, due to their deep roots, they extract water from much deeper soil layers. It has been demonstrated that forest cover causes water table depression and subsurface salt accumulation above shallow saline water table in areas with a negative water balance. The above mentioned situation caused by the afforestation in the Hungarian Great Plain is examined in the frame of a systematic study, which analyzed all affecting factors, like climatic water balance, water table depth and salinity, three species, subsoil layering and stand age. At the regional scale altogether 108 forested and neighbouring non forested plots are sampled. At the stand scale 18 representative forested and accompanying non forested plots (from the 108) are monitored intensively. In this paper dataset of two neighbouring plots (common oak forest and herbaceous vegetation) was compared (as first results of this complex investigation). On the basis of the analysis it could be summarized that under forest the water table was lower, and the amplitude of diel fluctuation of water table was significantly larger as under the herbaceous vegetation. Both results demonstrate greater groundwater use of forest vegetation. Groundwater uptake of the forest (which was calculated by diel based method) was almost same as potential reference evapotranspiration (calculated by Penman-Monteith equation with locally measured meteorological dataset) along the very dry summer of 2012. Larger amount of forest groundwater use is not parallel with salt uptake, therefore salt accumulates in soil and also in groundwater as can be measured of the representative monitoring sites as well. In the long run this process can result in the decline of biological production or even the dry out of some part of the forest. Greater groundwater uptake and salt accumulation

  7. Hydrothermal Carbonization of Municipal Woody and Herbaceous Prunings: Hydrochar Valorisation as Soil Amendment and Growth Medium for Horticulture

    Directory of Open Access Journals (Sweden)

    Monica Puccini

    2018-03-01

    Full Text Available In this study, we investigate the suitability of hydrochar, produced at industrial scale by hydrothermal carbonization of municipal woody and herbaceous prunings, to be used as soil amendment and peat substitute in organic growth medium for horticulture. Fresh hydrochar and the products of two different hydrochar post-treatments (i.e., washing and aging were compared in terms of potential phytotoxicity throughout physicochemical characterization and germination tests, performed with a sensitive species (Lactuca sativa. The results showed that the fresh hydrochar obtained from municipal green wastes complies with the Italian regulated parameters for the use as soil amendment. Moreover, hydrochar exhibits biological activity and a high content in organic C, Ca, and other micronutrients (Mg, Zn, Cu, Na, Cl. On the other hand, post-treatments are needed before application of hydrochar as peat substitute in potting mix, since appreciable phytotoxic effects on lettuce seed germination and radicle length of plantlets were observed (e.g., germination percentage of 56% and 54%, with 5 and 10 wt % of hydrochar in the blend, respectively. The inhibition of germination could be mainly attributed to the presence of polyphenols (tannins and volatile fatty acids, which were most effectively removed through the aging post-treatment.

  8. Leaf gas exchange of understory spruce-fir saplings in relict cloud forests, southern Appalachian Mountains, USA

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, K.; Smith, W.K. [Wake Forest Univ., Winston-Salem, NC (United States). Dept. of Biology

    2008-01-15

    Global climate change is expected to increase regional cloud ceiling levels in many mountainous forested areas of the world. This study investigated environmental influences on the gas exchange physiology of understory red spruce and Fraser fir trees at 2 sites in the Appalachian mountains. The study hypothesized that the humid, cloudy environment would influence the photosynthetic performance of the trees, and that the species would adapt to low, diffuse light. The study also predicted that leaf conductance to carbon dioxide (CO{sub 2}) would be high as a result of low leaf-to-air-vapour pressure deficit (LAVD). The study demonstrated that leaf conductance decreased exponentially as LAVD increased. Predawn leaf water potentials remained stable, while late afternoon values declined. It was concluded that leaf gas exchange was correlated with the response of leaf conductance and LAVD. The cloudy, humid environment strongly influenced tree leaf gas exchange and water relations. It was suggested that further research is needed to investigate cloud impacts on carbon gain and water relations. 72 refs., 1 tab., 8 figs.

  9. Classification of Herbaceous Vegetation Using Airborne Hyperspectral Imagery

    Directory of Open Access Journals (Sweden)

    Péter Burai

    2015-02-01

    Full Text Available Alkali landscapes hold an extremely fine-scale mosaic of several vegetation types, thus it seems challenging to separate these classes by remote sensing. Our aim was to test the applicability of different image classification methods of hyperspectral data in this complex situation. To reach the highest classification accuracy, we tested traditional image classifiers (maximum likelihood classifier—MLC, machine learning algorithms (support vector machine—SVM, random forest—RF and feature extraction (minimum noise fraction (MNF-transformation on training datasets of different sizes. Digital images were acquired from an AISA EAGLE II hyperspectral sensor of 128 contiguous bands (400–1000 nm, a spectral sampling of 5 nm bandwidth and a ground pixel size of 1 m. For the classification, we established twenty vegetation classes based on the dominant species, canopy height, and total vegetation cover. Image classification was applied to the original and MNF (minimum noise fraction transformed dataset with various training sample sizes between 10 and 30 pixels. In order to select the optimal number of the transformed features, we applied SVM, RF and MLC classification to 2–15 MNF transformed bands. In the case of the original bands, SVM and RF classifiers provided high accuracy irrespective of the number of the training pixels. We found that SVM and RF produced the best accuracy when using the first nine MNF transformed bands; involving further features did not increase classification accuracy. SVM and RF provided high accuracies with the transformed bands, especially in the case of the aggregated groups. Even MLC provided high accuracy with 30 training pixels (80.78%, but the use of a smaller training dataset (10 training pixels significantly reduced the accuracy of classification (52.56%. Our results suggest that in alkali landscapes, the application of SVM is a feasible solution, as it provided the highest accuracies compared to RF and MLC

  10. Diversity of Platygastridae in Leaf Litter and Understory Layers of Tropical Rainforests of the Western Ghats Biodiversity Hotspot, India.

    Science.gov (United States)

    Manoj, K; Rajesh, T P; Prashanth Ballullaya, U; Meharabi, K M; Shibil, V K; Rajmohana, K; Sinu, Palatty Allesh

    2017-06-01

    Platygastridae is the third largest family of parasitic Hymenoptera in the world. It includes important egg and larval parasitoids of insects and spiders. Therefore, Platygastridae is functionally important in maintaining the stability of tropical rainforests and agroecosystems. Although the diversity of Platygastridae is relatively well-known in agroecosystems, we know little about their diversity in tropical rainforests, and particularly about that of the leaf litter layer. Here, we address the importance of monitoring Platygastridae in tropical rainforests, using data from the relic primary forests of the sacred groves of the Western Ghats. First, we demonstrate that pitfall traps allow us to catch a wide array of representative diversity of Platygastridae of the tropical rainforests, and we establish an efficient collection method to study Platygastridae of leaf litter layer. Second, we demonstrate that the community structure and composition of Platygastridae of the leaf litter layer is different from that seen in the understory of the forests. This indirectly informs us that the Malaise traps capture only a minor subset of the species active in the rainforests. Third, we find that the dry and wet seasons captured dissimilar community of Platygastridae, suggesting that the season might alter the potential host species or host stages. We conclude that monitoring parasitic Hymenoptera in the leaf litter layer of tropical rainforests can provide fresh insights on the species distribution of both the parasitoids and their hosts, and allows us to examine the current state of the tropical rainforests from a functional point of view. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Herbaceous Plants for Climate Adaptation and Intensely Developed Urban Sites In Northern Europe: A Case Study From the Eastern Romanian Steppe

    Directory of Open Access Journals (Sweden)

    Sjöman Henrik

    2015-03-01

    Full Text Available In the increasingly compact city, services currently provided for in parks will in future be compressed into smaller green unit-structures, often associated with paved surfaces. Left-over spaces in urban environments, such as traffic roundabouts and strips along paths, roads and other corridors, will be important in the future city in order to deliver different eco-system services, especially stormwater management. It is therefore essential to start now to develop the knowledge and experience needed to create sustainable plantings for these sites. This paper presents the findings of a field survey in eastern Romania that sought to identify potential species for urban paved plantings in the Scandinavian region (northern Europe. The research approach is rooted in the hypothesis that studies of natural vegetation systems and habitats where plants are exposed to environmental conditions similar to those in inner-city environments can: 1 identify new or non-traditional species and genotypes adapted to urban environments; and 2 supply information and knowledge about their use potential concerning growth, flowering, life form, etc. In total, 117 different herbaceous species, all of which experience water stress regimes comparable to those in urban paved sites in Scandinavia. The initial information obtained from this field survey present a base of knowledge of which species that have a future potential for use in urban environment, which is of great importance in the following work within this project instead of testing species randomly without this knowledge of the species tolerance and performance in similar habitats.

  12. Link between defoliation and light treatments on root vitality of five understory shrubs with different resistance to insect herbivory.

    Science.gov (United States)

    Karolewski, Piotr; Zadworny, Marcin; Mucha, Joanna; Napierała-Filipiak, Anna; Oleksyn, Jacek

    2010-08-01

    Understory shrubs are frequently attacked by insect herbivores. However, very little is known regarding possible interactions between light condition, defoliation (D) and fine root vitality (% live roots) and metabolic activity, and whether different plant strategies (compensation, trade-off and equilibrium) to defoliation depend on individual species light requirements. To explore the response of roots to such conditions, an experiment was established in which we experimentally removed 50% of leaves in 1-year-old seedlings of Sambucus nigra, Cornus sanguinea, Prunus serotina, Frangula alnus and Corylus avellana grown in 15% and full sunlight. On average, defoliation leads to a 15% reduction in fine root (vitality (% live roots). However, a statistically significant reduction in root vitality after defoliation was detected only in those species that are less herbivorized in nature (48% in S. nigra and 5% in C. sanguinea). On average, shade conditions (L) resulted in 18% decline in root vitality, and the effects of defoliation were also 22% higher than for plants grown in full light. Root vitality in both treatments (D and L) was significantly correlated with their dry mass, concentration of total phenol (TPh) and carbon to nitrogen ratio, and negatively correlated with nitrogen, soluble carbohydrates, starch and total non-structural carbohydrates (TNC). To a large extent, root vitality and chemistry varied by species. Higher root vitality was related to higher concentrations of phenolics, more than to N and TNC concentrations. Concentrations of phenolics also differed significantly between defoliated plants and controls. However, in defoliated plants, an increase in TPh was observed only in two species, which belong to two different groups in light requirements and susceptibility to insect grazing (C. sanguinea and P. serotina). This study indicated that higher vitality of roots occurred in species that are characterized by higher insect defoliation under natural

  13. When growing tall is not an option : contrasting shade avoidance responses in two wild Geranium species

    NARCIS (Netherlands)

    Gommers, C.M.M.

    2016-01-01

    Plants can deal with shade in different ways. Sun-adapted species express a set of growth traits to reach for light; the so-called shade avoidance syndrome (SAS). However, shade-tolerant species from the forest understory are not able to outgrow surrounding trees and adopt a tolerance strategy

  14. Fire frequency and tree canopy structure influence plant species diversity in a forest-grassland ecotone

    Science.gov (United States)

    David W. Peterson; Peter B. Reich

    2008-01-01

    Disturbances and environmental heterogeneity are two factors thought to influence plant species diversity, but their effects are still poorly understood in many ecosystems. We surveyed understory vegetation and measured tree canopy cover on permanent plots spanning an experimental fire frequency gradient to test fire frequency and tree canopy effects on plant species...

  15. Occurrence of different phytoplasma infections in wild herbaceous dicots growing in vineyards affected by bois noir in Tuscany (Italy

    Directory of Open Access Journals (Sweden)

    Guido MARCHI

    2015-12-01

    Full Text Available Wild herbaceous dicotyledonous plants (dicots showing symptoms ascribable to phytoplasma disorders were found to be widely distributed in organic vineyards in central Tuscany (Italy affected by bois noir, a grapevine yellows disease caused by “Candidatus Phytoplasma solani”. In 2010 symptomatic dicots were tentatively identified to species level and the incidence of symptoms estimated in two selected vineyards in the province of Florence. Incidence ranged from 2 to 77%, and was not related to the relative abundance of hosts since very common species as well as relatively rare ones were consistently found to be symptomatic. PCR indexing and 16S rRNA sequence analyses indicated that two phytoplasmas co-existed in the vineyards: “Ca. P. solani”, infecting the root systems of 17 taxa, and a phytoplasma closely related to “Ca. P. phoenicium”, infecting 11 taxa, and occasionally co-infecting the same plant. Regardless of the high frequency of both pathogens in the vineyards, only “Ca. P. solani” could be detected in the grapevines. Population screening by means of tuf sequence analyses revealed the presence of only the tuf-b “Ca. P. solani” type both in dicot hosts and grapevine. This supports current notions of bois noir epidemiology, indicating that some infected dicots act as sources of “Ca. P. solani” inoculum whereas others are dead-end hosts. When the same specimens were screened by sequence analysis of the vmp1 gene, evidence was found that different phytoplasma genotypes may be predominant in grapevines and dicots.

  16. MONITORING PHENOLOGY OF FLOODPLAIN GRASSLAND AND HERBACEOUS VEGETATION WITH UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    W. K. van Iersel

    2016-06-01

    Full Text Available River restoration projects, which aim at improved flood safety and increased ecological value, have resulted in more heterogeneous vegetation. However, they also resulted in increasing hydraulic roughness, which leads to higher flood water levels during peak discharges. Due to allowance of vegetation development and succession, both ecological and hydraulic characteristics of the floodplain change more rapidly over time. Monitoring of floodplain vegetation has become essential to document and evaluate the changing floodplain characteristics and associated functioning. Extraction of characteristics of low vegetation using single-epoch remote sensing data, however, remains challenging. The aim of this study was to (1 evaluate the performance of multi-temporal, high-spatial-resolution UAV imagery for extracting temporal vegetation height profiles of grassland and herbaceous vegetation in floodplains and (2 to assess the relation between height development and NDVI changes. Vegetation height was measured six times during one year in 28 field plots within a single floodplain. UAV true-colour and false-colour imagery of the floodplain were recorded coincidently with each field survey. We found that: (1 the vertical accuracy of UAV normalized digital surface models (nDSMs is sufficiently high to obtain temporal height profiles of low vegetation over a growing season, (2 vegetation height can be estimated from the time series of nDSMs, with the highest accuracy found for combined imagery from February and November (RMSE = 29-42 cm, (3 temporal relations between NDVI and observed vegetation height show different hysteresis behaviour for grassland and herbaceous vegetation. These results show the high potential of using UAV imagery for increasing grassland and herbaceous vegetation classification accuracy.

  17. Herbaceous Peony (Paeonia lactiflora Pall. as an Alternative Source of Oleanolic and Ursolic Acids

    Directory of Open Access Journals (Sweden)

    Jun Tao

    2011-01-01

    Full Text Available Oleanolic acid (OA and ursolic acid (UA have been proven to possess many biological activities, and much attention is focused on the search for plants which are rich in OA and UA. In this report, the OA and UA accumulation characteristics were investigated in 47 cultivars of Chinese herbaceous peony (Paeonia lactiflora Pall. and were followed in three cultivars over different developmental stages as measured by high performance liquid chromatography (HPLC. OA and UA levels in leaves and stems demonstrated an overall upward trend from May 1 to September 15 except for UA in the leaves of “Hong Feng”. The maximum values of OA and UA in leaves of “Yangfei Chu Yu”, “Fen Zhu Pan” and “Hong Feng” were 852.98, 575.60, 290.48 μg/g FW and 924.94, 827.36, 432.67 μg/g FW, respectively. The maximum values of OA and UA in stems of “Yangfei Chu Yu”, “Fen Zhu Pan” and “Hong Feng” were 359.28, 90.49, 43.90 μg/g FW and 326.86, 82.25, 56.63 μg/g FW, respectively. OA and UA contents in leaves of 47 different herbaceous peony cultivars ranged from 66.73–618.12 and 36.23–665.14 μg/g FW, respectively, with average values of 171.62 and 227.57 μg/g FW, respectively. The results suggested that the aboveground parts of herbaceous peony may be used as an alternative source of OA and UA for medicinal purposes in addition to its ornamental purposes.

  18. Impact of herbaceous vegetation on the enzymatic activity of coal mining wastes

    Energy Technology Data Exchange (ETDEWEB)

    Osmanczyk, D

    1980-01-01

    Differences in the enzymatic activity of reclaimed and crude dump wastes after coal mining were investigated. Due to the increased activity of six investigated enzymes (dehydrogenase, catalase, saccharase, BETA-glucosidase, urease and asparaginase), a favourable impact of herbaceous vegetation on the biological activation of the breeding-ground was noticed. Particularly in the case of sacharase and BETA-glucosidase, an increase of the enzymatic activity at a rate of several times or even more than ten times speaks not only for an adequate increase of the metabolic rate of carbohydrates but also for specific properties of the habitat which favours an adsorption of these enzymes. (6 refs.) (In Polish)

  19. Species groups occupying different trophic levels respond differently to the invasion of semi-natural vegetation by Solidago canadensis

    NARCIS (Netherlands)

    Groot, de M.; Kleijn, D.; Jogan, N.

    2007-01-01

    We studied the impact of the invasive plant species Solidago canadensis on the species richness of vascular plants and the abundance, species richness and diversity of butterflies, hoverflies and carabid beetles in herbaceous semi-natural habitats near Ljubljana, Slovenia. The species groups were

  20. Rural herbaceous plant diversity under different land uses in North Zhejiang Province%浙北地区不同土地利用下乡村草本层植物多样性研究

    Institute of Scientific and Technical Information of China (English)

    吴灏; 张建锋; 陈光才; 汪庆兵; 王丽; 张颖

    2016-01-01

    , farming area for comparing plant diversity un-der different artificial habits, and three parameters such as Shannon-Wiener index, Simpson index, Sorensen index were employed. The results showed that based on the investigation, there were 162 species including 47 families, 123 genera, were found in all the habits. The principal species was from Compositae and Gramineae, accounted for 31.48% of the total. The highest plant diversity was in farming area, Shannon-wiener index value reaching 2.76 and Simpson index value being 0.91, Sorensen index value of 0.57, the same with rivers. From the farming area, rivers, gardens to artificial forest habitat, the value of herbaceous species diversity overall decreased. Moreover, taking green-ing measures would lead to herbaceous species reduction. For example, from the paddy field to farming area habitat, the main herb family and genus composition did not change significantly, plants of Cyperaceae, Compositae and Gra-mineae still occupied the main body. The composition of the main species of herbaceous plant community had changed, the herb species of Cyperaceae, Compositae and Gramineae were 11, 8 and 15 in the paddy field habitat, Cyperaceae, Compositae and Gramineae species were 4, 19 and 17 in the farming area habitat. Comparison of two kinds of habitats in herbaceous species composition, species number of cyperaceae reduced, compositae species number increased. Ad-ditionally, Alternanthera philoxeroides, Solidago canadensis and Dysphania ambrosioides, total three invasive species were found in four habitats, and their important values were so low that they could not constitute a significant impact on native species. By the research it implied that different land use types seriously affected the species composition and species diversity of herb community. The herbaceous community changed with land use types variation, diversification of land use could contribute native herbaceous species diversity protection. Hence, to study on the

  1. Disking and mid- and understory removal following an above-average acorn crop in three mature oak forests in southern Indiana

    Science.gov (United States)

    Ronald A. Rathfon; Nathanael I. Lichti; Robert K. Swihart

    2008-01-01

    We disked using small-scale equipment in the understory of three mature upland oak (Quercus) forests in southern Indiana immediately following acorn dispersal in an aboveaverage seed crop year as a means of improving oak seedling establishment. Three different mid- and understory removal treatments were also applied to create favorable light...

  2. EASTERN DODDER (CUSCUTA MONOGYNA VAHL.) SEED GERMINATION AFFECTED BY SOME HERBACEOUS DISTILLATES.

    Science.gov (United States)

    Movassaghi, M; Hassannejad, S

    2015-01-01

    Eastern dodder (Cuscuta monogyna Vahl.) is one of the noxious parasitic weeds that infected many ornamental trees in green spaces and gardens. Our purpose is to find natural inhibitors for prevention of its seed germination. In order to reach this aim, laboratory studies were conducted by using of herbaceous distillates of Dracocephalum moldavica, Nasturtium officinalis, Malva neglecta, Mentha piperita, Mentha pulegium, Rosa damascene, Ziziphora tenuior, and Urtica dioica on seed germination of C. monogyna. Z. tenuior distillate stimulated C. monogyna seed germination, whereas others reduced this parasitic weed's seed germination. D. moldavica caused maximum inhibition on weed seed germination. Seedling growth of C. monogyna was more affected than its seed germination. All of these herbaceous distillates reduced C. monogyna seedling length so that the latter decreased from 28.2 mm in distilled water to 4.5, 3.97, 3.85, 3.67, 3.1, 2.87, 2.57, 1.9, and 1.17 in M. pulegium, M. piperita, F. officinalis, Z. tenuior, N. officinalis, M. neglecta, R. damascene, U. dioica and D. moldavica, respectively. By using these medicinal plants distillates instead of herbicides, the parasitic weed seedling length and host plant infection will reduce.

  3. Deforestation fires versus understory fires in the Amazon Basin: What can we learn from satellite-based CO measurements?

    Science.gov (United States)

    Martinez-Alonso, S.; Deeter, M. N.; Worden, H. M.; Gille, J. C.; Clerbaux, C.; George, M.

    2014-12-01

    Deforestation fires in the Amazon Basin abound during the dry season (July to October) and are mostly associated with "slash and burn" agricultural practices. Understory fires occur when fires escape from deforested areas into neighboring standing forests; they spread slowly below the canopy, affecting areas that may be comparable or even larger than clear-cut areas. The interannual variabilities of understory fires and deforestation rates appear to be uncorrelated. Areas burned in understory fires are particularly extensive during droughts. Because they progress below a canopy of living trees, understory fires and their effects are not as easily identifiable from space as deforestation fires. Here we analyze satellite remote sensing products for CO and fire to investigate differences between deforestation fires and understory fires in the Amazon Basin under varying climatic conditions. The MOPITT (Measurements Of Pollution In The Troposphere) instrument on board NASA's Terra satellite has been measuring tropospheric CO since 2000, providing the longest global CO record to date. IASI (the Infrared Atmospheric Sounding Interferometer) A and B are two instruments on board METOP-A and -B, respectively, measuring, among others, CO since 2006 and 2012. MODIS (the Moderate Resolution Imaging Spectroradiometer) instruments on board NASA's Terra and Aqua satellites provide, among other products, a daily record of fires and their effects since 2000 and 2002, respectively. The temporal extent of all these datasets allows for the detailed analysis of drought versus non-drought years. Initial results indicate that MOPITT CO emissions during the dry season peaked in 2005, 2007, and 2010. Those were draught years and coincide with peaks in area affected by understory fires.

  4. Evidence of correlated evolution and adaptive differentiation of stem and leaf functional traits in the herbaceous genus, Helianthus.

    Science.gov (United States)

    Pilote, Alex J; Donovan, Lisa A

    2016-12-01

    Patterns of plant stem traits are expected to align with a "fast-slow" plant economic spectrum across taxa. Although broad patterns support such tradeoffs in field studies, tests of hypothesized correlated trait evolution and adaptive differentiation are more robust when taxa relatedness and environment are taken into consideration. Here we test for correlated evolution of stem and leaf traits and their adaptive differentiation across environments in the herbaceous genus, Helianthus. Stem and leaf traits of 14 species of Helianthus (28 populations) were assessed in a common garden greenhouse study. Phylogenetically independent contrasts were used to test for evidence of correlated evolution of stem hydraulic and biomechanical properties, correlated evolution of stem and leaf traits, and adaptive differentiation associated with source habitat environments. Among stem traits, there was evidence for correlated evolution of some hydraulic and biomechanical properties, supporting an expected tradeoff between stem theoretical hydraulic efficiency and resistance to bending stress. Population differentiation for suites of stem and leaf traits was found to be consistent with a "fast-slow" resource-use axis for traits related to water transport and use. Associations of population traits with source habitat characteristics supported repeated evolution of a resource-acquisitive "drought-escape" strategy in arid environments. This study provides evidence of correlated evolution of stem and leaf traits consistent with the fast-slow spectrum of trait combinations related to water transport and use along the stem-to-leaf pathway. Correlations of traits with source habitat characteristics further indicate that the correlated evolution is associated, at least in part, with adaptive differentiation of Helianthus populations among native habitats differing in climate. © 2016 Botanical Society of America.

  5. Do agrometeorological data improve optical satellite-based estimations of the herbaceous yield in Sahelian semi-arid ecosystems?

    DEFF Research Database (Denmark)

    Diouf, Abdoul Aziz; Hiernaux, Pierre; Brandt, Martin Stefan

    2016-01-01

    evapotranspiration satellite gridded data to estimate the annual herbaceous yield in the semi-arid areas of Senegal. It showed that a machine-learning model combining FAPAR seasonal metrics with various agrometeorological data provided better estimations of the in situ annual herbaceous yield (R2 = 0.69; RMSE = 483...... kg·DM/ha) than models based exclusively on FAPAR metrics (R2 = 0.63; RMSE = 550 kg·DM/ha) or agrometeorological variables (R2 = 0.55; RMSE = 585 kg·DM/ha). All the models provided reasonable outputs and showed a decrease in the mean annual yield with increasing latitude, together with an increase...

  6. Linking hard and soft traits: Physiology, morphology and anatomy interact to determine habitat affinities to soil water availability in herbaceous dicots.

    Science.gov (United States)

    Belluau, Michaël; Shipley, Bill

    2018-01-01

    Species' habitat affinities along environmental gradients should be determined by a combination of physiological (hard) and morpho-anatomical (soft) traits. Using a gradient of soil water availability, we address three questions: How well can we predict habitat affinities from hard traits, from soft traits, and from a combination of the two? How well can we predict species' physiological responses to drought (hard traits) from their soft traits? Can we model a causal sequence as soft traits → hard traits → species distributions? We chose 25 species of herbaceous dicots whose affinities for soil moisture have already been linked to 5 physiological traits (stomatal conductance and net photosynthesis measured at soil field capacity, water use efficiency, stomatal conductance and soil water potential measured when leaves begin to wilt). Under controlled conditions in soils at field capacity, we measured five soft traits (leaf dry matter content, specific leaf area, leaf nitrogen content, stomatal area, specific root length). Soft traits alone were poor predictors (R2 = 0.129) while hard traits explained 48% of species habitat affinities. Moreover, hard traits were significantly related to combinations of soft traits. From a priori biological knowledge and hypothesized ecological links we built a path model showing a sequential pattern soft traits → hard traits → species distributions and accounting for 59.6% (p = 0.782) of habitat wetness. Both direct and indirect causal relationships existed between soft traits, hard traits and species' habitat preferences. The poor predictive abilities of soft traits alone were due to the existence of antagonistic and synergistic direct and indirect effects of soft traits on habitat preferences mediated by the hard traits. To obtain a more realistic model applicable to a population level, it has to be tested in an experiment including species competition for water supply.

  7. Herbivores modify selection on plant functional traits in a temperate rainforest understory.

    Science.gov (United States)

    Salgado-Luarte, Cristian; Gianoli, Ernesto

    2012-08-01

    There is limited evidence regarding the adaptive value of plant functional traits in contrasting light environments. It has been suggested that changes in these traits in response to light availability can increase herbivore susceptibility. We tested the adaptive value of plant functional traits linked with carbon gain in contrasting light environments and also evaluated whether herbivores can modify selection on these traits in each light environment. In a temperate rainforest, we examined phenotypic selection on functional traits in seedlings of the pioneer tree Aristotelia chilensis growing in sun (canopy gap) and shade (forest understory) and subjected to either natural herbivory or herbivore exclusion. We found differential selection on functional traits depending on light environment. In sun, there was positive directional selection on photosynthetic rate and relative growth rate (RGR), indicating that selection favors competitive ability in a high-resource environment. Seedlings with high specific leaf area (SLA) and intermediate RGR were selected in shade, suggesting that light capture and conservative resource use are favored in the understory. Herbivores reduced the strength of positive directional selection acting on SLA in shade. We provide the first demonstration that natural herbivory rates can change the strength of selection on plant ecophysiological traits, that is, attributes whose main function is resource uptake. Research addressing the evolution of shade tolerance should incorporate the selective role of herbivores.

  8. The influence of gap size on plant species diversity and composition in beech (Fagus orientalis forests, Ramsar, Mazandaran Province, North of Iran

    Directory of Open Access Journals (Sweden)

    MARZIEH BEGYOM-FAGHIR

    2013-10-01

    Full Text Available Pourbabaei H, Haddadi-Moghaddam H, Begyom-Faghir M, Abedi T. 2013. The influence of gap size on plant species diversity and composition in beech (Fagus orientalis forests, Ramsar, Mazandaran Province, North of Iran. Biodiversitas 14: 89-94.This study was conducted to investigate the influence of gap size on plant species diversity and composition in beech (Fagus orientalis Lipsky. forests, Ramsar, Mazandaran province. Fifteen gaps in small, medium, and large sizes were randomly selected. Abundance of tree saplings, shrubs and herbaceous species were counted on 4 m2 micro-plots within the gaps. Diversity indices including Shannon-Wiener, Simpson, Mc Arthur's N1, Hill's N2, species richness and Smith-Wilson’s evenness index were computed. The results revealed that there was significant difference among three gap categories in terms of diversity. The highest diversity values of tree and herbaceous species were obtained in the large gaps, while the highest diversity value of shrub species was in the medium gaps. Species composition of small gaps (28 species: 7 trees and 21 herbaceous, medium gaps (37 species: 7 trees, 5 shrubs and 25 herbaceous and large gaps (40 species: 7 trees, 4 shrubs and 29 herbaceous were recognized. Therefore, based on the results of this study, it is recommended that in order to maintain plant diversity and composition up to 400 m2 gap size cloud be used in this forests.

  9. Slope variation and population structure of tree species from different ecological groups in South Brazil.

    Science.gov (United States)

    Bianchini, Edmilson; Garcia, Cristina C; Pimenta, José A; Torezan, José M D

    2010-09-01

    Size structure and spatial arrangement of 13 abundant tree species were determined in a riparian forest fragment in Paraná State, South Brazil (23°16'S and 51°01'W). The studied species were Aspidosperma polyneuron Müll. Arg., Astronium graveolens Jacq. and Gallesia integrifolia (Spreng) Harms (emergent species); Alseis floribunda Schott, Ruprechtia laxiflora Meisn. and Bougainvillea spectabilis Willd. (shade-intolerant canopy species); Machaerium paraguariense Hassl, Myroxylum peruiferum L. and Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl. (shade-tolerant canopy species); Sorocea bonplandii (Baill.) Bürger, Trichilia casaretti C. Dc, Trichilia catigua A. Juss. and Actinostemon concolor (Spreng.) Müll. Arg. (understory small trees species). Height and diameter structures and basal area of species were analyzed. Spatial patterns and slope correlation were analyzed by Moran's / spatial autocorrelation coefficient and partial Mantel test, respectively. The emergent and small understory species showed the highest and the lowest variations in height, diameter and basal area. Size distribution differed among emergent species and also among canopy shade-intolerant species. The spatial pattern ranged among species in all groups, except in understory small tree species. The slope was correlated with spatial pattern for A. polyneuron, A. graveolens, A. floribunda, R. laxiflora, M. peruiferum and T. casaretti. The results indicated that most species occurred in specific places, suggesting that niche differentiation can be an important factor in structuring the tree community.

  10. Lasiodiplodia species associated with dying Euphorbia ingens in ...

    African Journals Online (AJOL)

    Various species of Euphorbia occur in South Africa, including herbaceous, succulent and woody types. The largest of the succulent Euphorbia spp. in South Africa is Euphorbia ingens. These trees have been dying at an alarming rate in the Limpopo province during the course of the last 15 years. Investigations into the ...

  11. Factors affecting the species composition of arable field boundary vegetation

    NARCIS (Netherlands)

    Kleijn, D.; Verbeek, M.

    2000-01-01

    1. In recent decades the botanical diversity of arable field boundaries has declined drastically. To determine the most important factors related to the species composition of arable field boundaries, the vegetation composition of 105 herbaceous boundaries, 1-m wide, in the central and eastern

  12. Elevated native terrestrial snail abundance and diversity in association with an invasive understory shrub, Berberis thunbergii, in a North American deciduous forest

    Science.gov (United States)

    Utz, Ryan M.; Pearce, Timothy A.; Lewis, Danielle L.; Mannino, Joseph C.

    2018-01-01

    Invasive terrestrial plants often substantially reshape environments, yet how such invasions affect terrestrial snail assemblages remains understudied. We investigated how snail assemblages in deciduous forest soils with dense Berberis thunbergii (Japanese barberry), an invasive shrub in eastern North America, differ from forest areas lacking the shrub. Leaf litter and soil samples were collected from forest patches with dense B. thunbergii understories and adjacent control areas within two exurban forest tracts in western Pennsylvania, U.S.A. Snails were identified to species and quantified by standard diversity metrics. Contrary to our expectations, snails were significantly more abundant and diverse in B. thunbergii-invaded areas. Despite differences in abundance, the snail community composition did not differ between invaded and control habitats. The terrestrial snail assemblage we observed, which was composed entirely of native species, appears to respond favorably to B. thunbergii invasion and therefore may not be negatively impacted by physicochemical changes to soils typically observed in association with the plant. Such findings could reflect the fact that B. thunbergii likely creates more favorable habitat for snails by creating cooler, more humid, and more alkaline soil environments. However, the snail assemblages we retrieved may consist mostly of species with high tolerance to environmental degradation due to a legacy of land use change and acid deposition in the region.

  13. Response of loblolly pine to complete woody and herbaceous control: projected yields and economic outcomes - the COMProject

    Science.gov (United States)

    James H. Miller; R.L. Busby; B.R. Zutter; S.M. Zedaker; M.B. Edwards; R.A. Newbold

    1995-01-01

    Abstract.Age-8 and -9 data from the 13 study plantations of the Competition Omission Monitoring Project (COMP) were used to project yields and derive economic outcomes for loblolly pine (Pinus taeda L.). COMP treatments were chop-burn, complete woody plant control, complete herbaceous plant control for 4 years, and complete woody...

  14. Effets du pâturage sur la biomasse herbacée et sur des paramètres ...

    African Journals Online (AJOL)

    Results indicate that grazing decreases significantly herbaceous aboveground biomass (but not root biomass). However, grazing does not impact soil chemical and biological parameters, except for soil basal respiration that increases significantly in grazing situation. Thus, after 18 months of exclosure, we detect very little ...

  15. Adapting to change in banana-based farming systems of northwest Tanzania: the potential role of herbaceous legumes

    NARCIS (Netherlands)

    Baijukya, F.P.

    2004-01-01

    Keywords: Land use changes; Herbaceous legumes; Adoptability; N 2 -fixation; Residual effect; Legume management; Exploration of options, Nutrient depleted soils.The banana-based farming system in

  16. Changes in habitat use at rainforest edges through succession: A case study of understory birds in the Brazilian Amazon

    Science.gov (United States)

    Luke L. Powell; Gustavo Zurita; Jared D.  Wolfe; Erik I.  Johnson; Philip C  Stouffer

    2015-01-01

    Primary tropical rain forests are being rapidly perforated with new edges via roads, logging, and pastures, and vast areas of secondary forest accumulate following abandonment of agricultural lands. To determine how insectivorous Amazonian understory birds respond to edges between primary rain forest and three age classes of secondary forest, we radio-tracked two...

  17. Spectral contribution of understory to forest reflectance in a boreal site: an analysis of EO-1 Hyperion data

    Czech Academy of Sciences Publication Activity Database

    Rautianien, M.; Lukeš, Petr

    2015-01-01

    Roč. 171, dec (2015), s. 98-104 ISSN 0034-4257 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : forest reflectance model * hyperspectral * boreal * leaf area index * understory Subject RIV: EH - Ecology, Behaviour Impact factor: 5.881, year: 2015

  18. Estimating individual tree mid- and understory rank-size distributions from airborne laser scanning in semi-arid forests

    Science.gov (United States)

    Tyson L. Swetnam; Donald A. Falk; Ann M. Lynch; Stephen R. Yool

    2014-01-01

    Limitations inherent to airborne laser scanning (ALS) technology and the complex sorting and packing relationships of forests complicate accurate remote sensing of mid- and understory trees, especially in denser forest stands. Self-similarities in rank-sized individual tree distributions (ITD), e.g. bole diameter or height, are a well-understood property of natural,...

  19. On the formation of dense understory layers in forests worldwide: consequences and implications for forest dynamics, biodiversity, and succession

    Science.gov (United States)

    Alejandro A. Royo; Walter P. Carson

    2006-01-01

    The mechanistic basis underpinning forest succession is the gap-phase paradigm in which overstory disturbance interacts with seedling and sapling shade tolerance to determine successional trajectories. The theory, and ensuing simulation models, typically assume that understory plants have little impact on the advance regeneration layer's composition. We challenge...

  20. Understory vegetation response after 30 years of interval prescribed burning in two ponderosa pine sites in northern Arizona, USA

    Science.gov (United States)

    Catherine A. Scudieri; Carolyn Hull Sieg; Sally M. Haase; Andrea E. Thode; Stephen S. Sackett

    2010-01-01

    Southwestern USA ponderosa pine (Pinus ponderosa C. Lawson var. scopulorum Engelm.) forests evolved with frequent surface fires and have changed dramatically over the last century. Overstory tree density has sharply increased while abundance of understory vegetation has declined primarily due to the near cessation of fires. We...

  1. Managing Japanese stiltgrass dominated communities in the ridge and valley physiographic province in eastern West Virginia

    Science.gov (United States)

    David W. McGill; William N. Grafton; Jonathan A. Pomp

    2008-01-01

    Japanese stiltgrass (Microstegium vimineum) is an exotic invasive species that can dominate forest understories and suppress native herbaceous and woody species. This study had two objectives: 1) to assess directed spray herbicides for controlling M. vimineum; and 2) to collect a set of factors that affect management of M...

  2. Promoting and maintaining diversity in contemporary hardwood forests: Confronting contemporary drivers of change and the loss of ecological memory

    Science.gov (United States)

    Christopher R. Webster; Yvette L. Dickinson; Julia I. Burton; Lee E. Frelich; Michael A. Jenkins; Christel C. Kern; Patricia Raymond; Michael R. Saunders; Michael B. Walters; John L. Willis

    2018-01-01

    Declines in the diversity of herbaceous and woody plant species in the understory of eastern North American hardwood forests are increasingly common. Forest managers are tasked with maintaining and/or promoting species diversity and resilience; however, the success of these efforts depends on a robust understanding of past and future system dynamics and identification...

  3. Forest Understory Fire in the Brazilian Amazon in ENSO and Non-ENSO Years: Area Burned and Committed Carbon Emissions

    Science.gov (United States)

    Alencar, A.; Nepstad, D.; Ver-Diaz, M. Del. C.

    2004-01-01

    "Understory fires" that burn the floor of standing forests are one of the most important types of forest impoverishment in the Amazon, especially during the severe droughts of El Nino Southern Oscillation (ENSO) episodes. However, we are aware of no estimates of the areal extent of these fires for the Brazilian Amazon and, hence, of their contribution to Amazon carbon fluxes to the atmosphere. We calculated the area of forest understory fires for the Brazilian Amazon region during an El Nino (1998) and a non El Nino (1995) year based on forest fire scars mapped with satellite images for three locations in eastern and southern Amazon, where deforestation is concentrated. The three study sites represented a gradient of both forest types and dry season severity. The burning scar maps were used to determine how the percentage of forest that burned varied with distance from agricultural clearings. These spatial functions were then applied to similar forest/climate combinations outside of the study sites to derive an initial estimate for the Brazilian Amazon. Ninety-one percent of the forest area that burned in the study sites was within the first kilometer of a clearing for the non ENSO year and within the first four kilometers for the ENSO year. The area of forest burned by understory forest fire during the severe drought (ENSO) year (3.9 millions of hectares) was 13 times greater than the area burned during the average rainfall year (0.2 million hectares), and twice the area of annual deforestation rate. Dense forest was, proportionally, the forest area most affected by understory fires during the El Nino year, while understory fires were concentrated in transitional forests during the year of average rainfall. Our estimate of aboveground tree biomass killed by fire ranged from 0.06 Pg to 0.38 Pg during the ENSO and from 0,004 Pg to 0,024 Pg during the non ENSO.

  4. Diaporthe species on Rosaceae with descriptions of D. pyracanthae sp. nov. and D. malorum sp. nov.

    NARCIS (Netherlands)

    Santos, L.; Phillips, A.J.L.; Crous, P.W.; Alves, A.

    2017-01-01

    The family Rosaceae includes a large number of species ranging from herbaceous (Fragaria) to ornamental plants (Rosa and Pyracantha) and fruit trees (Malus and Pyrus). Diaporthe species have been associated with twig canker, shoot blight, dieback, wood decay and fruit rot on members of the Rosaceae.

  5. Ecosystem and restoration consequences of invasive woody species removal in Hawaiian lowland wet forest

    Science.gov (United States)

    R. Ostertag; S. Cordell; J. Michaud; T.C. Cole; J.R. Schulten; K.M. Publico; J.H. Enoka

    2009-01-01

    A removal experiment was used to examine the restoration potential of a lowland wet forest in Hawaii, a remnant forest type that has been heavily invaded by non-native species and in which there is very little native species regeneration. All non-native woody and herbaceous biomass (approximately 45% of basal area) was removed in four 100-m² removal plots;...

  6. Small mammals as indicators of cryptic plant species diversity in the central Chilean plant endemicity hotspot

    Directory of Open Access Journals (Sweden)

    Meredith Root-Bernstein

    2014-12-01

    Full Text Available Indicator species could help to compensate for a shortfall of knowledge about the diversity and distributions of undersampled and cryptic species. This paper provides background knowledge about the ecological interactions that affect and are affected by herbaceous diversity in central Chile, as part of the indicator species selection process. We focus on the ecosystem engineering role of small mammals, primarily the degu Octodon degus. We also consider the interacting effects of shrubs, trees, avian activity, livestock, slope, and soil quality on herbaceous communities in central Chile. We sampled herbaceous diversity on a private landholding characterized by a mosaic of savanna, grassland and matorral, across a range of degu disturbance intensities. We find that the strongest factors affecting endemic herbaceous diversity are density of degu runways, shrub cover and avian activity. Our results show that the degu, a charismatic and easily identifiable and countable species, could be used as an indicator species to aid potential conservation actions such as private protected area uptake. We map areas in central Chile where degus may indicate endemic plant diversity. This area is larger than expected, and suggests that significant areas of endemic plant communities may still exist, and should be identified and protected. Keywords: Cryptic species, Diversity, Endemic, Indicator species, Octodon degus, Plant

  7. Nitrogen Addition and Understory Removal but Not Soil Warming Increased Radial Growth of Pinus cembra at Treeline in the Central Austrian Alps

    Directory of Open Access Journals (Sweden)

    Andreas Gruber

    2018-05-01

    Full Text Available Beside low temperatures, limited tree growth at the alpine treeline may also be attributed to a lack of available soil nutrients and competition with understory vegetation. Although intra-annual stem growth of Pinus cembra has been studied intensively at the alpine treeline, the responses of radial growth to soil warming, soil fertilization, and below ground competition awaits clarification. In this study we quantified the effects of nitrogen (N fertilization, soil warming, and understory removal on stem radial growth of P. cembra at treeline. Soil warming was achieved by roofing the forest floor with a transparent polyvinyl skin, while understory competition was prevented by shading the forest floor with a non-transparent foil around six trees each. Six trees received N- fertilization and six other trees served as controls. Stem growth was monitored with band dendrometers during the growing seasons 2012–2014. Our 3 years experiment showed that soil warming had no considerable effect on radial growth. Though understory removal through shading was accompanied by root-zone cooling, understory removal as well as N fertilization led to a significant increase in radial growth. Hardly affected was tree root biomass, while N-fertilization and understory removal significantly increased in 100-needle surface area and 100-needle dry mass, implying a higher amount of N stored in needles. Overall, our results demonstrate that beside low temperatures, tree growth at cold-climate boundaries may also be limited by root competition for nutrients between trees and understory vegetation. We conclude that tree understory interactions may also control treeline dynamics in a future changing environment.

  8. Remember redcedar! An overlooked species reveals its potential

    Science.gov (United States)

    Joan O' Callaghan; Leslie Brodie; Constance Harrington; Peter Gould; Warren Devine

    2012-01-01

    People have long valued mature western redcedar for its strong, lightweight wood that is rot-resistant.The species has cultural importance for Northwest tribes who use the tree’s bark and roots as well as the wood. Redcedar is very shade-tolerant and is often found in the understory and midstory of Pacific Northwest forests. It is also very adaptable and can grow on a...

  9. Susceptibility of peach GF 305 seedlings and selected herbaceous plants to plum pox virus isolates from western Slovakia.

    Science.gov (United States)

    Glasa, M; Matisová, J; Hricovský, I; Kúdela, O

    1997-12-01

    The susceptibility of peach GF 305 seedlings and herbaceous plants to five plum pox virus (PPV) isolates from orchards of western Slovakia was investigated. PPV was isolated from diseased plum, apricot and peach trees, and transmitted by chip-budding to peach GF 305. The herbaceous plants were infected by mechanical inoculation. The transmission was analysed by symptomatology and double sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Infected peaches developed leaf distortion, tissue clearing along the veins and small chlorotic spots (isolate BOR-3). With exception of BOR-3, the PPV isolates transmitted from peach caused local chlorotic spots on Chenopodium foetidum. The character of symptoms changed when a sap from PPV-infected Nicotiana benthamiana was used as virus inoculum. From N. benthamiana, the PPV isolates could be transmitted to Pisum sativum, cv. Colmo (light green mosaic), N. clevelandii and N. clevelandii x N. glutinosa hybrid (latent infection or chlorotic spots).

  10. Effect of Calcium Sprays on Mechanical Strength and Cell Wall Fractions of Herbaceous Peony (Paeonia Lactiflora Pall. Inflorescence Stems

    Directory of Open Access Journals (Sweden)

    Jintao Ge

    2012-04-01

    Full Text Available Calcium is an essential element and imparts significant structural rigidity to the plant cell walls, which provide the main mechanical support to the entire plant. In order to increase the mechanical strength of the inflorescence stems of herbaceous peony, the stems are treated with calcium chloride. The results shows that preharvest sprays with 4% (w/v calcium chloride three times after bud emergence are the best at strengthening “Da Fugui” peonies’ stems. Calcium sprays increased the concentrations of endogenous calcium, total pectin content as well as cell wall fractions in herbaceous peonies stems, and significantly increased the contents of them in the top segment. Correlation analysis showed that the breaking force of the top segment of peonies’ stems was positively correlated with the ratio of water insoluble pectin to water soluble pectin (R = 0.673 as well as lignin contents (R = 0.926 after calcium applications.

  11. Promise of combined hydrothermal/chemical and mechanical refining for pretreatment of woody and herbaceous biomass.

    Science.gov (United States)

    Kim, Sun Min; Dien, Bruce S; Singh, Vijay

    2016-01-01

    Production of advanced biofuels from woody and herbaceous feedstocks is moving into commercialization. Biomass needs to be pretreated to overcome the physicochemical properties of biomass that hinder enzyme accessibility, impeding the conversion of the plant cell walls to fermentable sugars. Pretreatment also remains one of the most costly unit operations in the process and among the most critical because it is the source of chemicals that inhibit enzymes and microorganisms and largely determines enzyme loading and sugar yields. Pretreatments are categorized into hydrothermal (aqueous)/chemical, physical, and biological pretreatments, and the mechanistic details of which are briefly outlined in this review. To leverage the synergistic effects of different pretreatment methods, conducting two or more pretreatments consecutively has gained attention. Especially, combining hydrothermal/chemical pretreatment and mechanical refining, a type of physical pretreatment, has the potential to be applied to an industrial plant. Here, the effects of the combined pretreatment (combined hydrothermal/chemical pretreatment and mechanical refining) on energy consumption, physical structure, sugar yields, and enzyme dosage are summarized.

  12. Diversity of herbaceous plants and bacterial communities regulates soil resistome across forest biomes.

    Science.gov (United States)

    Hu, Hang-Wei; Wang, Jun-Tao; Singh, Brajesh K; Liu, Yu-Rong; Chen, Yong-Liang; Zhang, Yu-Jing; He, Ji-Zheng

    2018-04-24

    Antibiotic resistance is ancient and prevalent in natural ecosystems and evolved long before the utilization of synthetic antibiotics started, but factors influencing the large-scale distribution patterns of natural antibiotic resistance genes (ARGs) remain largely unknown. Here, a large-scale investigation over 4000 km was performed to profile soil ARGs, plant communities and bacterial communities from 300 quadrats across five forest biomes with minimal human impact. We detected diverse and abundant ARGs in forests, including over 160 genes conferring resistance to eight major categories of antibiotics. The diversity of ARGs was strongly and positively correlated with the diversity of bacteria, herbaceous plants and mobile genetic elements (MGEs). The ARG composition was strongly correlated with the taxonomic structure of bacteria and herbs. Consistent with this strong correlation, structural equation modelling demonstrated that the positive effects of bacterial and herb communities on ARG patterns were maintained even when simultaneously accounting for multiple drivers (climate, spatial predictors and edaphic factors). These findings suggest a paradigm that the interactions between aboveground and belowground communities shape the large-scale distribution of soil resistomes, providing new knowledge for tackling the emerging environmental antibiotic resistance. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Effects of peroxyacetyl nitrate (PAN) on vegetation. I. Herbaceous plants PAN injury symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Nouchi, I.; Iijima, T.; Oodaira, T.

    1975-01-01

    A series of exposure experiments were conducted in a controlled-atmosphere exposure chamber equipped with artificial light apparatus, using PAN synthesized from ultraviolet irradiation of ethyl nitrite vapor in oxygen. Exposures of 6 approx. 16 hours and 10 pphm PAN caused serious damage like caving with glazing or bronzing in caved lesions to the lower surface of younger leaves. Leaves of white-flowered petunia were found to be most sensitive to PAN and were damaged even by a 3 pphm exposure. Microscopic examinations showed that the PAN characteristically caused injuries of spongy cells and that these cells collapsed and turned brown. Leaf injury symptoms on herbaceous plants caused by synthesized PAN in the exposure experiments were found to be quite similar to those seen in the field under high oxidant emergence. Therefore, it seems that the said type of injuries to leaf beet, kidney bean, and head lettuce observed in the field were caused by PAN. 21 references. 4 figures, 3 tables.

  14. The rise of angiosperm-dominated herbaceous floras: Insights from Ranunculaceae.

    Science.gov (United States)

    Wang, Wei; Lin, Li; Xiang, Xiao-Guo; Ortiz, Rosa Del C; Liu, Yang; Xiang, Kun-Li; Yu, Sheng-Xiang; Xing, Yao-Wu; Chen, Zhi-Duan

    2016-06-02

    The rise of angiosperms has been regarded as a trigger for the Cretaceous revolution of terrestrial ecosystems. However, the timeframe of the rise angiosperm-dominated herbaceous floras (ADHFs) is lacking. Here, we used the buttercup family (Ranunculaceae) as a proxy to provide insights into the rise of ADHFs. An integration of phylogenetic, molecular dating, ancestral state inferring, and diversification analytical methods was used to infer the early evolutionary history of Ranunculaceae. We found that Ranunculaceae became differentiated in forests between about 108-90 Ma. Diversification rates markedly elevated during the Campanian, mainly resulted from the rapid divergence of the non-forest lineages, but did not change across the Cretaceous-Paleogene boundary. Our data for Ranunculaceae indicate that forest-dwelling ADHFs may have appeared almost simultaneously with angiosperm-dominated forests during the mid-Cretaceous, whereas non-forest ADHFs arose later, by the end of the Cretaceous terrestrial revolution. Furthermore, ADHFs were relatively unaffected by the Cretaceous-Paleogene mass extinction.

  15. Interception of wet deposited atmospheric pollutants by herbaceous vegetation: Data review and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Gonze, M.-A., E-mail: marc-andre.gonze@irsn.fr; Sy, M.M.

    2016-09-15

    Better understanding and predicting interception of wet deposited pollutants by vegetation remains a key issue in risk assessment studies of atmospheric pollution. We develop different alternative models, following either empirical or semi-mechanistic descriptions, on the basis of an exhaustive dataset consisting of 440 observations obtained in controlled experiments, from 1970 to 2014, for a wide variety of herbaceous plants, radioactive substances and rainfall conditions. The predictive performances of the models and the uncertainty/variability of the parameters are evaluated under Hierarchical Bayesian modelling framework. It is demonstrated that the variability of the interception fraction is satisfactorily explained and quite accurately modelled by a process-based alternative in which absorption of ionic substances onto the foliage surfaces is determined by their electrical valence. Under this assumption, the 95% credible interval of the predicted interception fraction encompasses 81% of the observations, including situations where either plant biomass or rainfall intensity are unknown. This novel approach is a serious candidate to challenge existing empirical relationships in radiological or chemical risk assessment tools. - Highlights: • Literature data on the interception of atmospheric pollutants by herbs were reviewed • Predictive models were developed and evaluated in the Bayesian modelling framework • Sensitivity of interception to environmental conditions was satisfactorily explained • 81% of the observations were satisfactorily predicted by a semi-mechanistic model • This model challenges empirical relationships currently used in risk assessment tools.

  16. Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters

    Science.gov (United States)

    2009-12-01

    ER D C TR -0 9- 10 Strategic Environmental Research and Development Program Phytoremediation of Composition-B Derived TNT and RDX in...Program ERDC TR-09-10 December 2009 Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters Elly P. H...for U.S. Army Corps of Engineers Washington, DC 20314-1000 ERDC TR-09-10 ii Abstract: This report describes a study in which phytoremediation of

  17. Photochemical efficiency of adult and young leaves of the neotropical understory shrub Psychotria limonensis (Rubiaceaein response to changes in the light environment

    Directory of Open Access Journals (Sweden)

    Gerardo Avalos

    2004-12-01

    Full Text Available We explored the short-term adjustment in photochemical efficiency (Fv /Fm in adult and young leaves of the understory neotropical shrub Psychotria limonensis Krause (Rubiaceaein response to rapid changes in the light environment.Leaves were collected from 20 individual plants growing under sun and shade conditions on Gigante Peninsula,Barro Colorado Natural Monument (Republic of Panama,during the wet season of 1996. Leaves were distributed in four sequences of light treatments (AB leaves were expanded under sun and were transferred to shade,BA leaves experienced the opposite transfer,and the controls AA and BB leaves that were expanded and maintained under sun or shade conditions.Adult and young leaves did not differ in overall photochemical efficiency.Instead,differences were found among light environments,for which leaves transferred from shade to sun showed the lowest F v /F m ratios.There was no relationship between photochemical efficiency and leaf temperature.In P.limonensis,understory plants are susceptible of photoinhibition independently of the leaf ontogenetic stage.The approach utilized in this experiment allowed the rapid exploration of this capacity, and could be applied to poorly studied understory species. Rev.Biol.Trop.52(4:839-844.Epub 2005 Jun 24.Se exploró el ajuste a corto plazo en la eficiencia fotosintética (Fv /Fm en hojas jovenes y adultas del arbusto del sotobosque neotropical Psychotria limonensis Krause (Rubiaceaeen respuesta a cambios rápidos de luz ambiental. Las hojas fueron recolectadas de 20 plantas individuales bajo condiciones de sol y sombra en Peninsula Gigante, Monumento Natural Barro Colorado (Panamá,durante la estación lluviosa de 1996.Las hojas fueron distribuidas en una secuencia cuatro tratamientos de luz (AB las hojas fueron expandidas bajo el sol y fueron transferidas a la sombra,BA las hojas experimentaron la transferencia contraria,y las hojas controles AA y BB que fueron expandidas y mantenidas

  18. Developing and Testing a Robust, Multi-Scale Framework for the Recovery of Longleaf Pine Understory Communities

    Science.gov (United States)

    2015-05-01

    effects on seed germination of native and invasive Eastern deciduous forest understory plants. Forest Ecology and Management 261:1401–1408. Estes, J...Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204...in longleaf pine savannas. Figure 3.3.2. Results of multivariate classification and regression tree analysis. Figure 3.3.3. Comparison of Classes

  19. A Simple Method for Retrieving Understory NDVI in Sparse Needleleaf Forests in Alaska Using MODIS BRDF Data

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2014-12-01

    Full Text Available Global products of leaf area index (LAI usually show large uncertainties in sparsely vegetated areas because the understory contribution is not negligible in reflectance modeling for the case of low to intermediate canopy cover. Therefore, many efforts have been made to include understory properties in LAI estimation algorithms. Compared with the conventional data bank method, estimation of forest understory properties from satellite data is superior in studies at a global or continental scale over long periods. However, implementation of the current remote sensing method based on multi-angular observations is complicated. As an alternative, a simple method to retrieve understory NDVI (NDVIu for sparse boreal forests was proposed in this study. The method is based on the fact that the bidirectional variation in NDVIu is smaller than that in canopy-level NDVI. To retrieve NDVIu for a certain pixel, linear extrapolation was applied using pixels within a 5 × 5 target-pixel-centered window. The NDVI values were reconstructed from the MODIS BRDF data corresponding to eight different solar-view angles. NDVIu was estimated as the average of the NDVI values corresponding to the position in which the stand NDVI had the smallest angular variation. Validation by a noise-free simulation data set yielded high agreement between estimated and true NDVIu, with R2 and RMSE of 0.99 and 0.03, respectively. Using the MODIS BRDF data, we achieved an estimate of NDVIu close to the in situ measured value (0.61 vs. 0.66 for estimate and measurement, respectively and reasonable seasonal patterns of NDVIu in 2010 to 2013. The results imply a potential application of the retrieved NDVIu to improve the estimation of overstory LAI for sparse boreal forests and ultimately to benefit studies on carbon cycle modeling over high-latitude areas.

  20. Ecological effects of cell-level processes: genome size, functional traits and regional abundance of herbaceous plant species

    Czech Academy of Sciences Publication Activity Database

    Herben, Tomáš; Suda, Jan; Klimešová, Jitka; Mihulka, S.; Říha, P.; Šímová, I.

    2012-01-01

    Roč. 110, č. 7 (2012), s. 1357-1367 ISSN 0305-7364 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : perennials * phylogenetic correction * path analysis Subject RIV: EF - Botanics Impact factor: 3.449, year: 2012

  1. Plant distribution patterns related to species characteristics and spatial and temporal habitat heterogeneity in a network of ditch banks

    NARCIS (Netherlands)

    Geertsema, W.; Sprangers, J.T.C.M.

    2002-01-01

    In this study we investigated the relationship between the distribution patterns of a number of herbaceous plant species and the isolation and age of habitat patches. The study was conducted for a network of ditch banks in an agricultural landscape in The Netherlands. Thirteen plant species were

  2. The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C-3 species

    NARCIS (Netherlands)

    Poorter, H; VanBerkel, Y; Baxter, R; DenHertog, J; Dijkstra, P; Gifford, RM; Griffin, KL; Roumet, C; Roy, J

    We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO2, These species comprised wild and agricultural herbaceous plants as well as tree seedlings, Both average responses

  3. The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C3 species

    NARCIS (Netherlands)

    Poorter, H.; Berkel, Y. van; Baxter, B.; Hertog, J. den; Dijkstra, P.; Gifford, R.M.; Griffin, K.L.; Roumet, C.; Roy, J.; Wong, S.C.

    1997-01-01

    We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO₂. These species comprised wild and agricultural herbaceous plants as well as tree seedlings. Both average

  4. Fuel treatment effects on soil chemistry and foliar physiology of three coniferous species at the Teakettle Experimental Forest, California, USA

    Science.gov (United States)

    Rakesh Minocha; Swathi A. Turlapati; Stephanie Long; Malcolm. North

    2013-01-01

    A full factorial design crossing overstory (O) and understory (U) thinning and prescribed burning (B) was started at Teakettle Experimental Forest, California, in 2001 with the aim of achieving shifts in species composition to favor fire-resistant pines over fir. The goal of the present study was to evaluate the use of metabolic changes as early indicators for...

  5. Two new species of Leandra s.str. (Melastomataceae) from the Atlantic Forest in Espírito Santo, Brazil

    NARCIS (Netherlands)

    Reginato, M.; Goldenberg, R.

    2012-01-01

    Two species of Leandra that occur in the Atlantic Forest, in the state of Espírito Santo, eastern Brazil, are described and illustrated here. Leandra cristata has been found in the understory of montane rain forest, and can be recognized by the distinct nodal ridges on the young branches, by the

  6. Effects of short-rotation controlled burning on amphibians and reptiles in pine woodlands

    Science.gov (United States)

    Roger W. Perry; D. Craig Rudolph; Ronald E. Thill

    2012-01-01

    Fire is being used increasingly as a forest management tool throughout North America, but its effects on reptiles and amphibians in many ecosystems are unclear. Open woodlands with understories dominated by herbaceous vegetation benefit many wildlife species, but maintaining these woodlands requires frequent burning. Although many studies have compared herpetofaunal...

  7. A Guide to Bottomland Hardwood Restoration

    Science.gov (United States)

    2001-06-01

    floristically Ecological Importance of Understory diverse undergrowth may serve to pollinate flowers, Plants including those of trees. Undergrowth vegetation...Herbaceous plants include bedstraw, Variants and associated vegetation. Sycamore- violet, wild carrot, wild lettuce , amsonia, mint, legumes, pecan...elements of bottomland hardwood restoration such as species selection, site preparation, direct seeding, planting of seedlings, and alternative

  8. Changes of biomass in some perennial grass species. | M.C. ...

    African Journals Online (AJOL)

    Patterns of seasonal herbaceous biomass change in a burned, ungrazed savanna woodland are reported. A standard clipping technique was used and material farmed in the current season was separated from that formed in the previous season for three perennial grass species: Brachiaria nigropedata, Andropogon ...

  9. Potentials of flora species on the yield of honey in Dakka Forest ...

    African Journals Online (AJOL)

    The study assessed the potentials of flora on the yield of honey in Bali Local Government Area of Taraba State. Floral resources that could accommodate possible apicultural industry have not been examined in the study area. Data on plant species (trees, shrubs and herbaceous plants) utilized by honeybees were obtained ...

  10. Landscape variation in species diversity and succession as related to topography, soils and human disturbance

    Science.gov (United States)

    Jeffery N. Pearcy; David M. Hix; Stacy A. Drury

    1995-01-01

    Three hundred and thirty-two plots have been sampled on the Wayne National Forest of southeastern Ohio, for the purpose of developing an ecological classification system (ECS). The ECS will be based on the herbaceous and woody vegetation, soils and topography of mature (80-140 year-old), relatively-undisturbed forests. Species diversity changes little across this...

  11. Floristic composition of the dry tropical forest in biological reserve (sanctuary "Los Besotes" and phenology of the dominant arboreal species (Valledupar, Cesar, Colombia

    Directory of Open Access Journals (Sweden)

    Mary Lee Berdugo Lattke

    2015-01-01

    Full Text Available Based on the floristic composition and structural aspects, the formation tropical dry forest of the reserve "Los Besotes" (Valledupar, Cesar; 248 y 1046m of altitude was characterized. In 35 individuals from nine dominant tree species in two forest types, the phenological characteristics were assessed. Seven monitoring were performed along one year according to the scheme of distribution of rainfall. The leaf fall in the forests of Myrcianthes aff. fragrans and Brosimum alicastrum did not exceed 20% regardless of the climatic period (drought or rainy seasons. In others dominant understory species the leaf fall was less than 40%, thus species of the canopy are classified as evergreen while those of the understory as semideciduous. Blooming peaked during the dry season while fruit production peaked during the two rainy seasons. In the forest ofBursera simaruba and Pterocarpus acapulcensis the leaf fall exceeded 60% in the dry season, while in the rainy season was only 30%. The leaf fall increased to 60% in others dominant understory species. Both canopy as well as understory species are deciduous. Blooming was observed during the dry season (December to March, and July, but it is also likely to occur in October; fruit production was observed at the end of the rainy season. In the tropical dry forest formation evergreen plant communities with low values of leaf fall (40% and deciduous communities with values greater than 60% are recognized.

  12. Desempenho de bananeiras consorciadas com leguminosas herbáceas perenes Banana plant performance intercropping with perennial herbaceous legumes

    Directory of Open Access Journals (Sweden)

    Adriano Perin

    2009-12-01

    Full Text Available O emprego de plantas de cobertura em consórcio com bananeiras pode ser uma estratégia de manejo, possibilitando aumentos de produtividade associados à otimização de processos biológicos e maior estabilidade do sistema produtivo. Neste trabalho, objetivo-se avaliar o efeito da cobertura viva, formada por leguminosas herbáceas perenes sobre a produção de bananeira cultivar Nanicão. Os tratamentos foram: amendoim forrageiro (Arachis pintoi Krap. & Greg, cudzu tropical (Pueraria phaseoloides Benth., siratro (Macroptilium atropurpureum Urb., vegetação espontânea (dominada por Panicum maximum Jacq. e vegetação espontânea + N-fertilizante. Foi avaliado o desenvolvimento vegetativo das bananeiras entre abril/1999 e julho/2000 e os atributos de produtividade. O peso do cacho e da penca foram positivamente influenciados pelo siratro e cudzu tropical empregados como coberturas vivas, quando comparados aos demais tratamentos. Todas as leguminosas proporcionaram maior crescimento das bananeiras (notadamente a partir do 6º mês, maior número de folhas emitidas e maior proporção de cachos colhidos, em relação aos tratamentos com vegetação espontânea (com e sem N-fertilizante. As leguminosas siratro e cudzu tropical promoveram condições adequadas ao desenvolvimento das bananeiras, acarretando ganhos de produtividade e eliminação da adubação nitrogenada no bananal. O potencial benéfico das leguminosas cudzu tropical e siratro como coberturas vivas capazes de proporcionar aumentos na produtividade de banana, qualifica essas espécies como alternativa promissora para a fertilidade do solo e nutrição das bananeiras.The use of coverage plants in cover cropping with bananas can be a management strategy, increasing in productivity associated with the optimization of biological processes and greater stability of production system. The objective of this work was to evaluate the effect of live coverage by herbaceous perennial legume on

  13. Growth responses of young Douglas-fir and tanoak 11 years after various levels of hardwood removal and understory suppression in southwestern Oregon, USA

    Science.gov (United States)

    Harrington, T.B.; Tappeiner, John C.

    1997-01-01

    At two sites in southwestern Oregon, height, diameter, and crown width of young Douglas-fir (Pseudotsuga menziesii) and sprout-origin tanoak (Lithocarpus densiflorus) were measured 1–11 years after reducing the density of a 2-year-old tanoak stand to 0%, 25%, 50%, and 100% of its initial cover. Some plots also included suppression of understory vegetation. Tanoak cover developed linearly with time, with steepness of the growth trajectory increasing at a diminishing rate with increasing percentage of initial tanoak cover. Fifth-year cover of understory vegetation declined linearly with increasing percentage of initial tanoak cover (R2 = 0.29). Survival of Douglas-fir (96–100%) differed little among initial abundances of tanoak, while growth trajectories for its size became increasingly exponential with decreasing percentage of initial tanoak cover. Eleventh-year heights of Douglas-fir were similar for 0%, 25%, and 50% of initial tanoak cover; however, diameter increased linearly with decreasing percentage of initial tanoak cover (R2 = 0.73), and the slope of the relationship steepened with understory suppression. Our results indicate that young stands exhibiting a wide range of stand compositions and productivities can be established by early manipulations of tanoak and understory abundance. Complete removal of tanoak plus understory suppression are necessary to maximize Douglas-fir growth, while productive, mixed stands can be achieved by removing 50% or more of tanoak cover.

  14. Species-specific growth responses to climate variations in understory trees of a Central African rain forest

    NARCIS (Netherlands)

    Couralet, C.; Sterck, F.J.; Sass-Klaassen, U.; Acker, Van J.; Beekman, H.

    2010-01-01

    Basic knowledge of the relationships between tree growth and environmental variables is crucial for understanding forest dynamics and predicting vegetation responses to climate variations. Trees growing in tropical areas with a clear seasonality in rainfall often form annual growth rings. In the

  15. Demography and mobility of three common understory butterfly species from tropical rain forest of Papua New Guinea

    Czech Academy of Sciences Publication Activity Database

    Vlašánek, Petr; Novotný, Vojtěch

    2015-01-01

    Roč. 57, č. 2 (2015), s. 445-455 ISSN 1438-3896 R&D Projects: GA ČR(CZ) GA14-04258S; GA MŠk(CZ) LH11008 Grant - others:National Science Foundation(US) DEB 0841885; GA JU(CZ) 121/2010/P; GA JU(CZ) 136/2010/P; European Social Fund(CZ) CZ.1.07/2.3.00/20.0064 Institutional support: RVO:60077344 Keywords : Jolly-Seber * Lepidoptera * mark-release-recapture Subject RIV: EH - Ecology, Behaviour Impact factor: 1.698, year: 2015 http://link.springer.com/article/10.1007%2Fs10144-015-0480-7

  16. [Effects of highway on the vegetation species composition along a distance gradient from road edge in southeastern margin of Tengeer Desert].

    Science.gov (United States)

    Feng, Li; Li, Xin-Rong; Guo, Qun; Zhang, Jing-Guang; Zhang, Zhi-Shan

    2011-05-01

    Aimed to examine the effects of highway on the vegetation species composition in arid desert area, forty-eight transects perpendicular to the provincial highway 201 from Shapotou to Jing-tai in the southeastern margin of Tengger Desert were installed, with the vegetation species distribution along a distance gradient from the road edge investigated. The results showed that with increasing distance from the road edge, the species number, coverage, biomass, and alpha-diversity of herbaceous plants declined, but had no significant differences with the control beyond 5 m. Within 0-6 m to the road edge, the herbaceous plant height was greater than that of the control, but their density had less change. Within 0-2 m to the road edge, the species turnover rate of herbaceous plants was lower; at 2-5m, this rate was the highest; while beyond 10 m, the species composition of herbaceous plants was similar to that of the control. The herbaceous plant community at the road edge was dominated by gramineous plants, with the disturbance-tolerant species Pennisetum centrasiaticum, Chloris virgata, and Agropyron cristatum accounting for 68.6% of the total. C. virgata beyond 1 m to the road edge had a rapid decrease in its individual number and presence frequency, P. centrasiaticum and A. cristatum beyond 2 m also showed a similar trend, while the composite plants Artemisia capillaris and A. frigida beyond 2 m from the road edge had a rapid increase in its individual number, accounting for 70% of the herbaceous plants. At the road edge, the coverage and density of shrubs were significantly lower than those of the control, but the species composition had no significant difference.

  17. Factors contributing to the recalcitrance of herbaceous dicotyledons (forbs) to enzymatic deconstruction.

    Science.gov (United States)

    Jabbour, Dina; Angelos, Evan R; Mukhopadhyay, Achira; Womboldt, Alec; Borrusch, Melissa S; Walton, Jonathan D

    2014-04-05

    Many different feedstocks are under consideration for the practical production of biofuels from lignocellulosic materials. The best choice under any particular combination of economic, agronomic, and environmental conditions depends on multiple factors. The use of old fields, restored prairie, or marginal lands to grow biofuel feedstocks offers several potential benefits including minimal agronomic inputs, reduced competition with food production, and high biodiversity. However, a major component of such landscapes is often herbaceous dicotyledonous plants, also known as forbs. The potential and obstacles of using forbs as biofuel feedstocks compared to the more frequently considered grasses and woody plants are poorly understood. The factors that contribute to the yield of fermentable sugars from four representative forbs were studied in comparison with corn stover. The forbs chosen for the study were lamb's quarters (Chenopodium album), goldenrod (Solidago canadensis), milkweed (Asclepias syriaca), and Queen Anne's lace (Daucus carota). These plants are taxonomically diverse, widely distributed in northern temperate regions including the continental United States, and are weedy but not invasive. All of the forbs had lower total glucose (Glc) content from all sources (cell walls, sucrose, starch, glucosides, and free Glc) compared to corn stover (range 16.2 to 23.0% on a dry weight basis compared to 39.2% for corn stover). When digested with commercial enzyme mixtures after alkaline pretreatment, yields of Glc as a percentage of total Glc were lower for the forbs compared to corn stover. Enzyme inhibition by water-extractable compounds was not a significant contributor to the lower yields. Based on experiments with optimized cocktails of pure glycosyl hydrolases, enzyme imbalance probably accounted for much of the lower yields. Addition of xyloglucanase and α-xylosidase, two enzymes targeting Glc-containing polysaccharides that are more abundant in dicotyledonous

  18. Couverts herbacés pérennes et enjeux environnementaux (en particulier eutrophisation) : atouts et limites

    OpenAIRE

    Vertes, Francoise; Benoit, Marc; Dorioz, Jean Marcel

    2010-01-01

    Outre des fonctions de production, les prairies assurent diverses fonctions environnementales dont la protection de la qualité des eaux et des sols. Dans quelle mesure et à quelles conditions ces fonctions non productives sont elles assurées par les couverts herbacés pérennes ? Après la présentation des principaux processus impliqués dans les cycles de l'azote et du phosphore, les moyens de limiter les pertes en N et P sont rappelés, à l'échelle de la parcelle, de l'exploitation et du bassin ...

  19. Phylogeographic patterns of the Aconitum nemorum species group (Ranunculaceae) shaped by geological and climatic events in the Tianshan Mountains and their surroundings

    Science.gov (United States)

    Xiao-Long Jiang; Ming-Li Zhang; Hong-Xiang Zhang; Stewart C. Sanderson

    2014-01-01

    To investigate the impacts of ancient geological and climatic events on the evolutionary history of the Aconitum nemorum species group, including A. nemorum s. str., A. karakolicum, and A. soongoricum; a total of 18 natural populations with 146 individuals were sampled, mainly from grassy slopes or the coniferous forest understory of the Tianshan Mountain Range and its...

  20. An Improved Estimation of Regional Fractional Woody/Herbaceous Cover Using Combined Satellite Data and High-Quality Training Samples

    Directory of Open Access Journals (Sweden)

    Xu Liu

    2017-01-01

    Full Text Available Mapping vegetation cover is critical for understanding and monitoring ecosystem functions in semi-arid biomes. As existing estimates tend to underestimate the woody cover in areas with dry deciduous shrubland and woodland, we present an approach to improve the regional estimation of woody and herbaceous fractional cover in the East Asia steppe. This developed approach uses Random Forest models by combining multiple remote sensing data—training samples derived from high-resolution image in a tailored spatial sampling and model inputs composed of specific metrics from MODIS sensor and ancillary variables including topographic, bioclimatic, and land surface information. We emphasize that effective spatial sampling, high-quality classification, and adequate geospatial information are important prerequisites of establishing appropriate model inputs and achieving high-quality training samples. This study suggests that the optimal models improve estimation accuracy (NMSE 0.47 for woody and 0.64 for herbaceous plants and show a consistent agreement with field observations. Compared with existing woody estimate product, the proposed woody cover estimation can delineate regions with subshrubs and shrubs, showing an improved capability of capturing spatialized detail of vegetation signals. This approach can be applicable over sizable semi-arid areas such as temperate steppes, savannas, and prairies.

  1. [Litter decomposition and soil faunal diversity of two understory plant debris in the alpine timberline ecotone of western Sichuan in a snow cover season].

    Science.gov (United States)

    He, Run-lian; Chen, Ya-mei; Deng, Chang-chun; Yan, Wan-qin; Zhang, Jian; Liu, Yang

    2015-03-01

    In order to understand the relationship between litter decomposition and soil fauna diversity during snow cover season, litterbags with plant debris of Actinothuidium hookeri, Cystopteris montana, two representative understory plants in the alpine timberline ecotone, and their mixed litter were incubated in the dark coniferous forest, timberline and alpine meadow, respectively. After a snow cover season, the mass loss and soil fauna in litterbags were investigated. After decomposition with a snow cover season, alpine meadow showed the highest mass loss of plant debris in comparison with coniferous forest and timberline, and the mass loss of A. hookeri was more significant. The mixture of two plants debris accelerated the mass loss, especially in the timberline. A total of 968 soil invertebrates, which belonged to 5 classes, 10 orders and 35 families, were captured in litterbags. Acarina and Collembola were the dominant groups in plant debris. The numbers of individuals and groups of soil faunal communities in litter of timberline were higher than those of alpine meadow and dark coniferous forest. Canonical correspondence analysis (CCA) indicated that the groups of soil animals were related closely with the average temperature, and endemic species such as Isoptera and Geophilomorpha were observed only in coniferous forest, while Hemiptera and Psocoptera only in.the alpine meadow. The diversity of soil faunal community was more affected by plant debris varieties in the timberline than in the coniferous forest and alpine meadow. Multiple regression analysis indicated that the average temperature and snow depth explained 30.8% of the variation of litter mass loss rate, soil animals explained 8.3%, and altogether explained 34.1%. Snow was one of the most critical factors impacting the decomposition of A. hookeri and C. montana debris in the alpine timberline ecotone.

  2. The nutritional quality of herbaceous legumes on goats: Intake, digestibility and nitrogen balances

    Directory of Open Access Journals (Sweden)

    Simon P Ginting

    2005-12-01

    Full Text Available The availability of forages is a critical factor that determine the sustainability of the animal-plantation production system. In this typical production system, cover crops could be an important sources of forages to support the animal production. The study is aimed to evaluate the nutritional quality (chemical compositions, intake, digestibility and N balances of herbaceous legumes namely Arachis pintoi and Arachis glabrata having potential for used as alternative cover crops in plantation. Centerocema pubescens, a conventional cover crops used in plantation, was used as control. Twenty-one mature male goats (16-18 kg were used in this experiment. The animals were put in individual metabolism cages, divided into three groups (7 animal per group based on the body weight, and were randomly allocated into one of the three forages. The experiment was run in a Completely Randomized Design. The animals were allocated to an adaptation period for 14 days, followed by intake measurement for 5 days and fecal and urine collection for the next 7 days. During the fecal and urine collection forages were offered at 90% of the maximum intake. Chemical analyses showed that the DM and OM contents were relatively equal among the forages, but the crude protein content of C. pubescens (23.56% are relatively higher than those of A. pintoi (16.94% or of A. glabrata (15.19% The fiber (NDF content was also relatively higher in C. pubescens (59.37% than in A. pintoi (16.94% or A. glabrata (41.50%. The forage intake was highest (P0.05 between goats fed A. pintoi (466 g/d or A. glabrata (453 g/d. A similar trend was seen when intake was expressed as % BW (3.80, 3.50 and 3.40, respectively or as g/kg BW0.75 (42.4, 39.5 and 38.4, respectively. The digestion coeficient of DM (81.3% or OM (83.5% were highest (P0.05 between A. glabrata (71.9 and 73.2%, respectively and C. pubescens (73.7 and 74.2%, respectively. The trends were the same with the digestion coeficient of ADF

  3. Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling

    OpenAIRE

    Mao, Bing; Mao, Rong; Zeng, De-Hui

    2017-01-01

    Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N ...

  4. Leaf Serration in Seedlings of Hetero blastic Woody Species Enhance Plasticity and Performance in Gaps But Not in the Under story

    International Nuclear Information System (INIS)

    Gamage, H.K.; Gamage, H.K.

    2010-01-01

    Leaf heteroblasty refers to dramatic ontogenetic changes in leaf size and shape, in contrast to homoblasty that exhibits little change, between seedling and adult stages. This study examined whether the plasticity in leaf morphology of heteroblastic species would be an advantage for their survival and growth over homoblastic congeners to changes in light. Two congeneric pairs of homoblastic (Hoheria lyallii, Aristotelia serrata) and heteroblastic species (H. sexstylosa, A. fruticosa) were grown for 18 months in canopy gap and forest understory sites in a temperate rainforest in New Zealand. Heteroblastic species that initially had serrated leaves reduced leaf serration in the understory, but increased in the gaps. Heteroblastic species also produced thicker leaves and had higher stomatal pore area (density x aperture length), maximum photosynthetic rate, survival, and greater biomass allocation to shoots than homoblastic relatives in the gaps. Findings indicate that increased leaf serration in heteroblastic species is an advantage over homoblastic congeners in high light.

  5. The hudiara drain wastewater effect on the distribution of surrounding herbaceous vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Shah, F R; Ahmad, N; Zahid, D M; Masood, K R; Ahmad, S.S., E-mail: dinmuhammadzahid@bzu.edu.p

    2010-06-15

    In this study, phytosociological survey using Braun-Blanquet's approach was undertaken to investigate the Hudiara drain wastewater influence on the surrounding vegetation. A total of 99 quadrats were laid to identify the plant species and altogether 66 species were recorded. Multivariate analysis of vegetation data (using CANOCO 4.5. software) classified the vegetation into two major communities including Cynodon dactylon, Boerhaavia diffusa, Parthenium hysterphorus and Xanthium strumarium groups. The presence of these species designated the area as waste land strongly supporting the growth of such species. The pattern of floral diversity was also not uniform and exhibited considerable variation. Canonical Correspondence Analysis revealed that the distribution of vegetation has correlation with environmental variables, but their role in the grouping of species remained non significant. However, soil EC played some role in the grouping of Stellaria media and Fagonia cretic. Similarly, some species viz., Ricinus communis, Boerhaavia diffusa and Phragmites karka showed a correlation with Fe and Cr respectively, suggesting Phragmites karka as a suitable candidate for chromium contaminated sites. (author)

  6. The hudiara drain wastewater effect on the distribution of surrounding herbaceous vegetation

    International Nuclear Information System (INIS)

    Shah, F.R.; Ahmad, N.; Zahid, D.M.; Masood, K.R.; Ahmad, S.S.

    2010-01-01

    In this study, phytosociological survey using Braun-Blanquet's approach was undertaken to investigate the Hudiara drain wastewater influence on the surrounding vegetation. A total of 99 quadrats were laid to identify the plant species and altogether 66 species were recorded. Multivariate analysis of vegetation data (using CANOCO 4.5. software) classified the vegetation into two major communities including Cynodon dactylon, Boerhaavia diffusa, Parthenium hysterphorus and Xanthium strumarium groups. The presence of these species designated the area as waste land strongly supporting the growth of such species. The pattern of floral diversity was also not uniform and exhibited considerable variation. Canonical Correspondence Analysis revealed that the distribution of vegetation has correlation with environmental variables, but their role in the grouping of species remained non significant. However, soil EC played some role in the grouping of Stellaria media and Fagonia cretic. Similarly, some species viz., Ricinus communis, Boerhaavia diffusa and Phragmites karka showed a correlation with Fe and Cr respectively, suggesting Phragmites karka as a suitable candidate for chromium contaminated sites. (author)

  7. Environmental Feedbacks of the Subalpine Ecotone Species in the Langtang National Park, Central Nepal Himalaya

    OpenAIRE

    Bhatta, K. P.; Rokaya, M. (Maan Bahadur); Münzbergová, Z. (Zuzana)

    2015-01-01

    Herbaceous species of the subalpine ecotone are mostly influenced by canopy cover and soil organic carbon. Species such as Gentiana argentea, Geranium donianum, Kobresia sp., Potentilla griffithii, Rubia wallichiana, Rubus nepalensis, Thalictrum chelidonii and Thalictrum cultratum are supposed to be critically sensitive to local environmental conditions due to having narrow amplitude to both the analyzed environmental variables. Although we have single-time data set from the sole existing hor...

  8. Efeito do ácido indolbutírico e raizon no enraizamento de estacas herbáceas e lenhosas de umbuzeiro = Effect of indolbutiric acid and raizon in the rooting of herbaceous and hardwoody cuttings of umbu tree

    Directory of Open Access Journals (Sweden)

    Luciane Arantes de Paula

    2007-07-01

    Full Text Available O umbuzeiro pode ser propagado assexuadamente, mas poucas informações se tem de que a espécie pode ser propagada por estaquia. Diante disso, o objetivo do trabalho foi avaliar o efeito de diferentes concentrações de AIB (ácido indolbutírico e do Raizon 05® no enraizamento de estacas herbáceas e lenhosas de umbuzeiro. Utilizou-se o delineamento experimental em bloco ao acaso, com quatro concentrações de AIB (0; 500; 1000 e 2000 mg L-1 e uma de Raizon 05® e dois tipos de estacas (herbácea e lenhosa. As estacas foramtratadas com Metiltiofan (Thiophanate methyl a 0,05% i.a. por um minuto, em seguida foram imersas nas soluções de AIB por dez minutos ou em contato com Raizon 05®. Realizou-se o plantio em tubetes plásticos contendo vermiculita média. O material permaneceu em telado com 50% de redução de luz, com nebulização intermitente. As variáveis analisadas foram: porcentagem de sobrevivência, enraizamento e massa seca das raízes. Pode-se concluir que: as estacas lenhosas apresentaram melhores resultados em relação às estacas herbáceas para a sobrevivência; o maior percentual de enraizamento foi verificado em estacas herbáceas com a aplicação de 500 mg L-1 de AIB, proporcionando33,33% de estacas enraizadas.The umbu tree can be propagated assexually, but few information are had that the species can be propagation by cutting. The objective of the present research was to evaluate the effect of different concentrations of IBA (indolbutiric acid and Raizon 05® in the rooting of cuttings herbaceous and hardwoody of umbu tree. The experimental design used was block at random, with four concentrations of IBA (0; 500; 1000 and 2000 mg L-1 and one of Raizon 05® and two types of cuttings (herbaceous and hardwoody. After the treatment of the cuttings with Metiltiofan (Thiophanate methyl a 0,05% i.a. for one minute, these were immersed in the solutions of IBA by ten minutes, or in contact with Raizon 05®, soon afterwards took

  9. Biomass and element pools of understory vegetation in the catchments of Čertovo Lake and Plešné Lake in the Bohemian Forest

    Czech Academy of Sciences Publication Activity Database

    Svoboda, M.; Matějka, K.; Kopáček, Jiří

    2006-01-01

    Roč. 61, Suppl. 20 (2006), S509-S521 ISSN 0006-3088 R&D Projects: GA ČR GA206/03/1583 Grant - others:MA(CZ) NAZV QG50105 Institutional research plan: CEZ:AV0Z60170517 Keywords : Norway spruce forest * understory vegetation Subject RIV: EH - Ecology, Behaviour Impact factor: 0.213, year: 2006

  10. Forest understory plant and soil microbial response to an experimentally induced drought and heat-pulse event: the importance of maintaining the continuum

    Science.gov (United States)

    Isabell von Rein; Arthur Gessler; Katrin Premke; Claudia Keitel; Andreas Ulrich; Zachary E. Kayler

    2016-01-01

    Drought duration and intensity are expected to increase with global climate change. How changes in water availability and temperature affect the combined plant–soil–microorganism response remains uncertain. We excavated soil monoliths from a beech (Fagus sylvatica L.) forest, thus keeping the understory plant–microbe communities intact, imposed an...

  11. Understory fern community structure, growth and spore production responses to a large-scale hurricane experiment in a Puerto Rico rainforest

    Science.gov (United States)

    Joanne M. Sharpe; Aaron B. Shiels

    2014-01-01

    Ferns are abundant in most rainforest understories yet their responses to hurricanes have not been well studied. Fern community structure, growth and spore production were monitored for two years before and five years after a large-scale experiment that simulated two key components of severe hurricane disturbance: canopy openness and debris deposition. The canopy was...

  12. Pentatomidae (Hemiptera: Heteroptera) in Herbaceous and Shrub Strata of Atlantic Forest Remnants in Northeastern Brazil.

    Science.gov (United States)

    Firmino, João V L; Mendonça, Milton D S; Lima, Iracilda M M; Grazia, Jocelia

    2017-06-01

    Most pentatomids are phytophagous, many of which are economically important crop pests. The family may also be a potentially important group to monitor the health of neotropical forests. However, there is a lack of biological inventories of Pentatomidae, especially in forest remnants of the Brazilian Atlantic forest. This is the first systematic survey of pentatomids reported in three Atlantic forest fragments in northeastern Brazil. In total, 997 individuals belonging to 38 species were recorded, some of which are considered economically important pests. Singletons and doubletons represented 45.9% of all species collected. The most abundant genera were Mormidea Amyot & Serville, 1843; Stictochilus Bergroth, 1918; Xynocoris Garbelotto & Campos 2014; and Edessa F., 1803. Species richness differed among fragments, with a richness gradient correlated with decreased urbanization and increased fragment size. The species abundance distribution fitted the logseries function but not the lognormal, in accordance with what is found for other assemblages in southern Brazil. Species composition also changed, in association with changes in temperature (revealed by the canonical correspondence analysis [CCA]), among fragments. Murici is one of the last remaining dense forests with high plant diversity in the region, having higher pentatomid species richness and a distinctive fauna. This first diversity study for Pentatomidae in fragments of tropical Atlantic Forest in northeastern Brazil reveals richness comparable with those from subtropical southern Brazil, with some species in common as well. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Rates of species loss from Amazonian forest fragments

    Science.gov (United States)

    Ferraz, Gonçalo; Russell, Gareth J.; Stouffer, Philip C.; Bierregaard, Richard O.; Pimm, Stuart L.; Lovejoy, Thomas E.

    2003-01-01

    In the face of worldwide habitat fragmentation, managers need to devise a time frame for action. We ask how fast do understory bird species disappear from experimentally isolated plots in the Biological Dynamics of Forest Fragments Project, central Amazon, Brazil. Our data consist of mist-net records obtained over a period of 13 years in 11 sites of 1, 10, and 100 hectares. The numbers of captures per species per unit time, analyzed under different simplifying assumptions, reveal a set of species-loss curves. From those declining numbers, we derive a scaling rule for the time it takes to lose half the species in a fragment as a function of its area. A 10-fold decrease in the rate of species loss requires a 1,000-fold increase in area. Fragments of 100 hectares lose one half of their species in <15 years, too short a time for implementing conservation measures. PMID:14614134

  14. A Regional Study of Loblolly Pine (Pinus taeda) Plantation Development During the First 15 Years After Early Complete Woody and/or Herbaceous Plant Control

    Science.gov (United States)

    James H. Miller; Bruce R. Zutter; Shepard M. Zedaker; M. Boyd Edwards; Ray A. Newbold

    2002-01-01

    Conifer plantations in North America and elsewhere in the world are increasingly cultured using early control of herbaceous and woody plants. Development of sustainable cultural practices are hindered by the absence of long-term data on productivity gains relative to competition levels, crop- competition dynamics, and ecological changes. There are lmany reports of...

  15. Biomass carbon, nitrogen and phosphorus stocks in hybrid poplar buffers, herbaceous buffers and natural woodlots in the riparian zone on agricultural land.

    Science.gov (United States)

    Fortier, Julien; Truax, Benoit; Gagnon, Daniel; Lambert, France

    2015-05-01

    In many temperate agricultural areas, riparian forests have been converted to cultivated land, and only narrow strips of herbaceous vegetation now buffer many farm streams. The afforestation of these riparian zones has the potential to increase carbon (C) storage in agricultural landscapes by creating a new biomass sink for atmospheric CO2. Occurring at the same time, the storage of nitrogen (N) and phosphorus (P) in plant biomass, is an important water quality function that may greatly vary with types of riparian vegetation. The objectives of this study were (1) to compare C, N and P storage in aboveground, belowground and detrital biomass for three types of riparian vegetation cover (9-year-old hybrid poplar buffers, herbaceous buffers and natural woodlots) across four agricultural sites and (2) to determine potential vegetation cover effects on soil nutrient supply rate in the riparian zone. Site level comparisons suggest that 9-year-old poplar buffers have stored 9-31 times more biomass C, 4-10 times more biomass N, and 3-7 times more biomass P than adjacent non managed herbaceous buffers, with the largest differences observed on the more fertile sites. The conversion of these herbaceous buffers to poplar buffers could respectively increase C, N and P storage in biomass by 3.2-11.9 t/ha/yr, 32-124 kg/ha/yr and 3.2-15.6 kg/ha/yr, over 9 years. Soil NO3 and P supply rates during the summer were respectively 57% and 66% lower in poplar buffers than in adjacent herbaceous buffers, potentially reflecting differences in nutrient storage and cycling between the two buffer types. Biomass C ranged 49-160 t/ha in woodlots, 33-110 t/ha in poplar buffers and 3-4 t/ha in herbaceous buffers. Similar biomass C stocks were found in the most productive poplar buffer and three of the four woodlots studied. Given their large and varied biomass C stocks, conservation of older riparian woodlots is equally important for C balance management in farmland. In addition, the

  16. Quantifying the Impact of Different Ways to Delimit Study Areas on the Assessment of Species Diversity of an Urban Forest

    Directory of Open Access Journals (Sweden)

    Rongxiao He

    2016-02-01

    Full Text Available Assessing the species diversity of an urban forest is important for understanding its structure and functions, but the result can be affected by sampling methods, times, and delimitations of the study area. In this study, we examined the influence of different ways to delimit boundaries of urban areas on the assessment of species diversity of urban forests through a case study conducted in Haikou, China. We surveyed the species diversity of the urban forest in Haikou twice using the same sampling protocol but two commonly used delimitations of the urban area. The two surveys produced significantly different estimates of species richness of the urban forest. Recorded species richness was 228 (144 woody and 84 herbaceous species and 303 (164 woody and 139 herbaceous species for the first and the second survey, respectively. The rarefaction analysis indicated that species richness of woody plants recorded in the two surveys could converge by doubling the sample size, but species richness of herbaceous plants was significantly different between the two surveys at the 95% confidence interval even at three times the original sample size. The value of the Simpson dissimilarity index between the two surveys was 0.417 and 0.357 for woody and herbaceous plants respectively, which implied noticeable dissimilarity of species compositions of plant assemblages in the two areas. We concluded that the assessment of biodiversity of an urban forest can be affected significantly by how the boundary of an urban area is defined. Caution should be taken when comparing species diversities of urban forests reported in different studies, especially when richness measures are used.

  17. Laboratory measurements of nitric oxide release from forest soil with a thick organic layer under different understory types

    Directory of Open Access Journals (Sweden)

    A. Bargsten

    2010-05-01

    Full Text Available Nitric oxide (NO plays an important role in the photochemistry of the troposphere. NO from soil contributes up to 40% to the global budget of atmospheric NO. Soil NO emissions are primarily caused by biological activity (nitrification and denitrification, that occurs in the uppermost centimeter of the soil, a soil region often characterized by high contents of organic material. Most studies of NO emission potentials to date have investigated mineral soil layers. In our study we sampled soil organic matter under different understories (moss, grass, spruce and blueberries in a humid mountainous Norway spruce forest plantation in the Fichtelgebirge (Germany. We performed laboratory incubation and flushing experiments using a customized chamber technique to determine the response of net potential NO flux to physical and chemical soil conditions (water content and temperature, bulk density, particle density, pH, C/N ratio, organic C, soil ammonium, soil nitrate. Net potential NO fluxes (in terms of mass of N from soil samples taken under different understories ranged from 1.7–9.8 ng m−2 s−1 (soil sampled under grass and moss cover, 55.4–59.3 ng m−2 s−1 (soil sampled under spruce cover, and 43.7–114.6 ng m−2 s−1 (soil sampled under blueberry cover at optimum water content and a soil temperature of 10 °C. The water content for optimum net potential NO flux ranged between 0.76 and 0.8 gravimetric soil moisture for moss covered soils, between 1.0 and 1.1 for grass covered soils, 1.1 and 1.2 for spruce covered soils, and 1.3 and 1.9 for blueberry covered soils. Effects of soil physical and chemical characteristics on net potential NO flux were statistically significant (0.01 probability level only for NH4+. Therefore, as an alternative explanation for the differences in soil biogenic NO emission we consider more biological factors like understory

  18. Effect of long-term understory prescribed burning on standing and down dead woody material in dry upland oak forests

    Science.gov (United States)

    Polo, John A.; Hallgren, S.W.; Leslie,, David M.

    2013-01-01

    Dead woody material, long ignored or viewed as a nuisance for forest management, has gained appreciation for its many roles in the forest including wildlife habitat, nutrient storage and cycling, energy for trophic webs, protection of soil, fuel for fire and carbon storage. The growing interest in managing dead woody material has created strong demand for greater understanding of factors controlling amounts and turnover. Prescribed burning, an important management tool, may have strong effects of dead woody material given fire’s capacity to create and consume dead woody material. We determined effects of long-term understory prescribed burning on standing and down woody material in upland oak forests in south-central North America. We hypothesized that as frequency of fire increased in these stands the amount of deadwood would decrease and the fine woody material would decrease more rapidly than coarse woody material. The study was conducted in forests dominated by post oak (Quercus stellata) and blackjack oak (Quercus marilandica) in wildlife management areas where understory prescribed burning had been practiced for over 20 years and the range of burn frequencies was 0 (unburned) fires per decade (FPD) to 4.6 FPD. The amount of deadwood was low compared with more productive forests in southeastern North America. The biomass (24.7 Mg ha-1) and carbon stocks (11.7 Mg ha-1) were distributed among standing dead (22%), coarse woody debris (CWD, dia. > 7.5 cm., 12%), fine woody debris (FWD, dia. prescribed burning influenced the amount and size distribution of standing and down dead woody material. There were two explanations for the lack of a detectable effect. First, a high incidence of severe weather including ice storms and strong winds that produce large amounts of deadwood intermittently in an irregular pattern across the landscape may preclude detecting a strong effect of understory prescribed burning. Second, fire suppression during the first one-half of the

  19. Is the inverse leafing phenology of the dry forest understory shrub Jacquinia nervosa (Theophrastaceae a strategy to escape herbivory?

    Directory of Open Access Journals (Sweden)

    Óscar M Chaves

    2006-09-01

    Full Text Available In the dry forest of Santa Rosa National Park, Costa Rica, the understory shrub Jacquinia nervosa presents an inverse pattern of phenology that concentrates vegetative growth and reproduction during the dry season. In this study, we tested the "escape from herbivory" hypothesis as a potential explanation for the inverse phenological pattern of J. nervosa. We monitored leaf, flower and fruit production in 36 adult plants from October 2000 to August 2001. Leaves of six randomly selected branches per plant were marked and monitored every two weeks to measure the cumulative loss in leaf area. To analyze pre-dispersal seed predation we collected 15 fruits per plant and counted the total number of healthy and damaged seeds, as well as the number and type of seed predators found within the fruits. Leaf, flower, and fruit production occurred during the first part of the dry season (end of November to February. The cumulative herbivory levels were similar to those observed in other tropical dry forest tree species that concentrate leaf production during the wet season, and were concentrated on young leaves, which lost an average of 36.77 % of their area (SD= 34.35 %, N= 195. Chewing beetles of the genus Epicauta (Meloidae were the most important herbivores. In mature leaves, most of the damage was caused by the beetle Coptocycla rufonotata (Chrysomelidae. Fruits took 4 months to develop during the dry season (January-March 2001 but continue increasing in size well into the first 3 months of the wet season (May-July. Average seed number per ripe fruit was 9 (SD = 5, N = 500. Seed predation in mature fruits was 42 % (SD = 47 %, N = 122. Most seeds were damaged by moth larvae of the family Tortricidae. Only 3 % of the flowers became fruits. This was influenced by the low level of flower synchrony (0.38±0.26, N = 36 plants, but neither leaf synchrony (0.88±0.06, N = 36 plants nor plant size influenced fruit numbers. The significant damaged produced

  20. Impact of the invasive plant Syzigium jambos (Myrtaceae on patterns of understory seedling abundance in a Tropical Premontane Forest, Costa Rica

    Directory of Open Access Journals (Sweden)

    Gerardo Avalos

    2006-06-01

    Full Text Available Habitat fragmentation, along with other human-induced disturbances, increase the vulnerability of native habitats to be invaded by aggressive, ecologically released, exotic species. Syzigium jambos (L. Alston (Myrtaceae, Rose Apple is an important invader still spreading throughout Hawaii, the Antilles, Central and South America. This study examines the effects of S. jambos on plant understory diversity in a 25 ha Tropical Premontane Moist Forest in Atenas, Alajuela, Costa Rica, a protected watershed that supplies drinking water for several human communities. Our final objective is to develop a management strategy combining water protection with the preservation of a representative sample of the original plant diversity in the area. Thirty 2 X 2 m plots were distributed throughout the Municipal Forest maintaining a minimum of 10 m between plots, and 2 m from trails, to sample all understory seedlings and saplings of S. jambos, Coffea arabica (coffee and tree seedlings. We found a clear dominance of S. jambos over all other understory plants. Of the total 1 285 sampled plants, S. jambos comprised 51%, coffee seedlings represented 14,78%, being the rest tree seedlings. Syzigium jambos had the highest density (5.46 plants/m2, S.D. = 6.44 compared to tree (3.67 plants/ m2, S.D. = 3.44 and coffee seedlings (1.58 plants/ m2, S.D. = 2.13. There was a highly significant negative relationship between the relative abundance of S. jambos and tree (r2 = 0.52, p La fragmentación del hábitat, junto con otros disturbios antropogénicos, aumentan la vulnerabilidad de los ambientes nativos a la invasión por especies exóticas, agresivas y sin controles ecológicos. Syzigium jambos (L. Alston (Myrtaceae, Manzana Rosa es una invasora importante que todavía está extendiendose en Hawaii, Las Antillas, Centro y Suramérica. Este estudio examina los efectos de S. jambos sobre la diversidad de plantas del sotobosque en un Bosque Húmedo Premontano de 25 ha en

  1. Evaluating vegetation management practices for woody and herbaceous vegetation : phase III : final report.

    Science.gov (United States)

    2017-08-01

    To train ODOT staff to recognize trees along the right-of-way that may be hazardous, identify trees that may be of a species-specific concern for vegetation management objectives, make pruning cuts based on industry standards, and oversee the tree wo...

  2. Reduced herbivory during simulated ENSO rainy events increases native herbaceous plants in semiarid Chile

    NARCIS (Netherlands)

    Manrique, R.; Gutierrez, J.R.; Holmgren, M.; Squeo, F.A.

    2007-01-01

    El Niño Southern Oscillation (ENSO) events have profound consequences for the dynamics of terrestrial ecosystems. Since increased climate variability is expected to favour the invasive success of exotic species, we conducted a field experiment to study the effects that simulated rainy ENSO events in

  3. Road–side herbaceous vegetation: life history groups and habitat preferences

    Czech Academy of Sciences Publication Activity Database

    Šerá, Božena

    2010-01-01

    Roč. 58, č. 1 (2010), s. 69-79 ISSN 1505-2249 R&D Projects: GA MŠk(CZ) OC 350.002 Institutional research plan: CEZ:AV0Z60870520 Keywords : road-side vegetation * road ecology * life form * life history * habitat preference * alien species Subject RIV: EH - Ecology, Behaviour Impact factor: 0.542, year: 2010

  4. effect of bush burning on herbaceous plant diversity in lagos state

    African Journals Online (AJOL)

    conducted to assess the effect of bush burning on plant species diversity. Three frequently burnt ... also believed to rid the grassland of parasitic insects and to prevent the encroachment of ..... The effect of smoke inhalation on lung function and ...

  5. Growth and nutrient content of herbaceous seedlings associated with biological soil crusts

    Science.gov (United States)

    R. L. Pendleton; B. K. Pendleton; G. L. Howard; S. D. Warren

    2003-01-01

    Biological soil crusts of arid and semiarid lands contribute significantly to ecosystem stability by means of soil stabilization, nitrogen fixation, and improved growth and establishment of vascular plant species. In this study, we examined growth and nutrient content of Bromus tectorum, Elymus elymoides, Gaillardia pulchella, and Sphaeralcea munroana grown in soil...

  6. An appraisal of ecological distribution of herbaceous flora at changa manga park lahore, pakistan

    International Nuclear Information System (INIS)

    Ahmad, S.S.; Erum, S.; Khan, S.M.

    2014-01-01

    The forest ground flora plays a vital role in cycling of nutrients, habitat preservation and rejuvenation of shrubs. The vegetation consociated with the forest plays a vital role in the protection, function of the forest ecosystem. Effective management of forest vegetation serves the forest ecosystem in assaying the balance of harmful effects of vying vegetation. Relationship of ecology between environment and vegetation and their ordination techniques and classification methods has become vital means in the research field vegetation ecology. Classification depends on the abundances of ground vegetation species. Multivariate technique is an important technique in ecology and biology for the group prediction. Classification of different plant communities had been accomplished by carrying out TWINSPAN analysis using PC-ORD. The results were shown in a two-way cluster dendrogram. A dendrogram is a hierarchical representation of species in graphical form. The encompassing survey has been conducted in the Changa Manga Forest (CMF) which resulted in the identification of the 45 species belonging to 24 families from all over the forest area. The TWINSPAN results of CMF ascertained the following dominant species in all of the four zones, Cynadon dactylon, Malvestrum cormendalianum, Oxalis corniculata, Parthenium hysterophorus, Desmostachya bipinnata. (author)

  7. Response of wetland herbaceous communities to gradients of light and substrate following disturbance by thermal pollution

    Science.gov (United States)

    Dunn, Christopher P.; Scott, Michael L.

    1987-01-01

    The influence of thermal disturbance and site characteristics on distribution of herbs was studied in portions of a 3020 ha wetland in the southeastern USA. Presence-absence of 52 species in 130 0.25 m2 plots was determined from four sites with different disturbance histories and from an undisturbed site. Data from the four disturbed sites were ordinated by detrended correspondence analysis. Differences in species composition among sites (coarse scale) were associated with water depth, light, and substrate type. Within a site (at a fine scale), correlation of environmental variables with ordination scores at a chronically disturbed site was weakly correlated with light (r=0.50). At two sites with episodic disturbance, species composition correlated significantly and positively with substrate and water depth. At a recovering site, vegetation patterns were moderately correlated with water depth (r=−0.52). Species richness was correlated with substrate type along the disturbance gradient. Our results are consistent the intermediate disturbance hypothesis and the subsidy-stress gradient concept.

  8. Prescribed grazing for management of invasive vegetation in a hardwood forest understory

    Science.gov (United States)

    Ronald A. Rathfon; Songlin Fei; Jason Tower; Kenneth Andries; Michael. Neary

    2014-01-01

    Land managers considering prescribed grazing (PG) face a lack of information on animal stocking rates, timing of grazing, and duration of grazing to achieve desired conditions in natural ecosystems under invasion stress from a variety of nonnative invasive plant (NNIP) species. In this study we tested PG treatments using goats for reducing NNIP brush species and...

  9. Seedling stage strategies as a means of habitat specialization in herbaceous plants

    DEFF Research Database (Denmark)

    ten Brink, Dirk-Jan; Bruun, Hans Henrik

    2011-01-01

    The regeneration niche has been little investigated in studies of community assembly and plant distribution. We examined adaptive associations between seedling traits and habitat specialization. Two habitat contrasts were investigated across several evolutionary lineages of angiosperms: species...... specialized to forest vs. open habitats and to dry vs. wet habitats. We also tested whether effects of shade and drought vary independently or, alternatively, if shade may amplify effects on drought-stressed plants. Seedling response in terms of growth rate, height, slenderness, specific leaf area (SLA......) and degree of elongation (longest internode; petiole or leaf-sheath depending on species' morphology) to light and watering treatments was assessed. We used a factorial design involving three light regimes and two watering frequencies. The open-shaded habitat contrast and the dry-wet habitat contrast were...

  10. Assessing plant community composition fails to capture impacts of white-tailed deer on native and invasive plant species.

    Science.gov (United States)

    Nuzzo, Victoria; Dávalos, Andrea; Blossey, Bernd

    2017-07-01

    Excessive herbivory can have transformative effects on forest understory vegetation, converting diverse communities into depauperate ones, often with increased abundance of non-native plants. White-tailed deer are a problematic herbivore throughout much of eastern North America and alter forest understory community structure. Reducing (by culling) or eliminating (by fencing) deer herbivory is expected to return understory vegetation to a previously diverse condition. We examined this assumption from 1992 to 2006 at Fermilab (Batavia, IL) where a cull reduced white-tailed deer ( Odocoileus virginianus ) abundance in 1998/1999 by 90 % from 24.6 to 2.5/km 2 , and at West Point, NY, where we assessed interactive effects of deer, earthworms, and invasive plants using 30 × 30 m paired fenced and open plots in 12 different forests from 2009 to 2012. We recorded not only plant community responses (species presence and cover) within 1 m 2 quadrats, but also responses of select individual species (growth, reproduction). At Fermilab, introduced Alliaria petiolata abundance initially increased as deer density increased, but then declined after deer reduction. The understory community responded to the deer cull by increased cover, species richness and height, and community composition changed but was dominated by early successional native forbs. At West Point plant community composition was affected by introduced earthworm density but not deer exclusion. Native plant cover increased and non-native plant cover decreased in fenced plots, thus keeping overall plant cover similar. At both sites native forb cover increased in response to deer reduction, but the anticipated response of understory vegetation failed to materialize at the community level. Deer-favoured forbs ( Eurybia divaricata , Maianthemum racemosum , Polygonatum pubescens and Trillium recurvatum ) grew taller and flowering probability increased in the absence of deer. Plant community monitoring fails to capture

  11. Plant-pollinator interactions over 120 years: loss of species, co-occurrence, and function.

    Science.gov (United States)

    Burkle, Laura A; Marlin, John C; Knight, Tiffany M

    2013-03-29

    Using historic data sets, we quantified the degree to which global change over 120 years disrupted plant-pollinator interactions in a temperate forest understory community in Illinois, USA. We found degradation of interaction network structure and function and extirpation of 50% of bee species. Network changes can be attributed to shifts in forb and bee phenologies resulting in temporal mismatches, nonrandom species extinctions, and loss of spatial co-occurrences between extant species in modified landscapes. Quantity and quality of pollination services have declined through time. The historic network showed flexibility in response to disturbance; however, our data suggest that networks will be less resilient to future changes.

  12. Trends in airborne pollen and pollen-season-related features of anemophilous species in Jaen (south Spain): A 23-year perspective

    Science.gov (United States)

    Ruiz-Valenzuela, Luis; Aguilera, Fátima

    2018-05-01

    Over the last few decades, global warming is prompting phenological changes in numerous plant species across Europe, and a trend towards rising airborne pollen concentrations has been detected. This study, focused on the most frequent pollen types from arboreal and herbaceous species in the airborne spectrum of Jaen (southern Spain), revealed significant changes in airborne pollen intensity and duration of the pollen season over the 23-year study period. Here Cupressaceae, Olea, Pinus, Platanus, Quercus as arboreal taxa and Plantago as herbaceous taxa were the most important with notable changes of at least three pollen season characteristics. Airborne pollen trends from arboreal taxa with high to very high allergenic potential are rising in line with the local temperature increasing trend, and their pollen seasons tend to end later and last longer. However, both the pollen concentrations and the duration of the pollen season of some herbaceous taxa are declining. The climate conditions projected for south Europe under different greenhouse emissions scenarios could continue to prompt greater pollen release and longer pollen season in tree species, especially those that flowering in winter and early spring, but these warming trends might be adverse for the local development of some herbaceous species and favorable for others sharing the same ecological niche. If similar warming trends accompany long-term climate change, greater exposure times to seasonal allergens may occur with subsequent effects on health.

  13. Functional Traits, Flocking Propensity, and Perceived Predation Risk in an Amazonian Understory Bird Community.

    Science.gov (United States)

    Martínez, Ari E; Gomez, Juan P; Ponciano, José Miguel; Robinson, Scott K

    2016-05-01

    Within a community, different species might share similar predation risks, and, thus, the ability of species to signal and interpret heterospecific threat information may determine species' associations. We combined observational, experimental, and phylogenetic approaches to determine the extent to which evolutionary history and functional traits determined flocking propensity and perceived predation risk (response to heterospecific alarm calls) in a lowland Amazonian bird community. We predicted that small birds that feed myopically and out in the open would have higher flocking propensities and account for a higher proportion of positive responses to alarms. Using generalized linear models and the incorporation of phylogeny on data from 56 species, our results suggest that phylogenetic relationships alongside body size, foraging height, vegetation density, and response to alarm calls influence flocking propensity. Conversely, phylogenetic relationships did not influence response to heterospecific alarm calls. Among functional traits, however, foraging strategy, foraging density, and flocking propensity partially explained responses to alarm calls. Our results suggest that flocking propensity and perceived predation risk are positively related and that functional ecological traits and evolutionary history may explain certain species' associations.

  14. Paenibacillus oenotherae sp. nov. and Paenibacillus hemerocallicola sp. nov., isolated from the roots of herbaceous plants.

    Science.gov (United States)

    Kim, Tae-Su; Han, Ji-Hye; Joung, Yochan; Kim, Seung Bum

    2015-08-01

    Two Gram-staining-positive, aerobic, endospore-forming, motile bacteria, strains DT7-4T and DLE-12T, were isolated from roots of evening primrose (Oenothera biennis) and day lily (Hemerocallis fulva), respectively, and subjected to taxonomic characterization. Analysis of 16S rRNA gene sequences indicated that the two strains fell into two distinct phylogenetic clusters belonging to the genus Paenibacillus. Strain DT7-4T was most closely related to Paenibacillus phyllosphaerae PALXIL04T and Paenibacillus taihuensis THMBG22T, with 96.3% 16S rRNA gene sequence similarity to each, and strain DLE-12T was most closely related to Paenibacillus ginsengarvi Gsoil 139T and Paenibacillus hodogayensis SGT, with 96.6 and 93.3% sequence similarity, respectively. Both isolates contained anteiso-C15 : 0 as the dominant fatty acid, meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan and MK-7 as the respiratory menaquinone. The cellular polar lipids were composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and unidentified polar lipids. The DNA G+C contents of strains DT7-4T and DLE-12T were 50.1 ± 0.7 and 55.2 ± 0.5 mol%, respectively. The chemotaxonomic properties of both isolates were typical of members of the genus Paenibacillus. However, our biochemical and phylogenetic analyses distinguished each isolate from related species. Based on our polyphasic taxonomic analysis, strains DT7-4T and DLE-12T should be recognized as representatives of novel species of Paenibacillus, for which the names Paenibacillus oenotherae sp. nov. (type strain DT7-4T = KCTC 33186T = JCM 19573T) and Paenibacillus hemerocallicola sp. nov. (type strain DLE-12T = KCTC 33185T = JCM 19572T) are proposed.

  15. Effects of visitor pressure on understory vegetation in Warsaw forested parks (Poland).

    Science.gov (United States)

    Sikorski, Piotr; Szumacher, Iwona; Sikorska, Daria; Kozak, Marcin; Wierzba, Marek

    2013-07-01

    Visitor's access to understorey vegetation in park forest stands results in the impoverishment of plant species composition and a reduction in habitat quality. The phenomenon of biotic homogenisation is typical in urban landscapes, but it can proceed differently depending on the scale, a detail that has not been observed in previous studies. This research was carried out in seven Warsaw parks (both public and restricted access). Thirty-four forested areas were randomly selected, some subjected to strong visitors' pressure and some within restricted access areas, free of such impacts. The latter category included woodlands growing in old forest and secondary habitats. Public access to the study areas contributed to the disappearance of some forest species and their replacement by cosmopolitan non-forest species, leading to loss of floristic biodiversity in areas of high ecological importance at the city scale. Some human-induced factors, including soil compaction and changes in soil pH, moisture and capillary volume, were found to cause habitat changes that favoured native non-forest plants. Despite changes in species composition, the taxonomic similarity of understorey vegetation in both categories--public access and restricted access--was comparable. In a distance gradient of measurements taken around selected individual trees, there was found to be significant variation (in light, soil pH and compaction) affecting the quality and quantity of understorey vegetation (including rare species). In conclusion, the protection of rare forest species could be achieved by limiting access to forested areas, particularly in old forest fragments, and we highly recommend its consideration in the proposal of future park restoration plans.

  16. Overexpression of herbaceous peony miR156e-3p improves anthocyanin accumulation in transgenic Arabidopsis thaliana lateral branches.

    Science.gov (United States)

    Zhao, Daqiu; Xia, Xing; Wei, Mengran; Sun, Jing; Meng, Jiasong; Tao, Jun

    2017-12-01

    microRNAs (miRNAs) play critical regulatory roles in plant growth and development. In the present study, the function of herbaceous peony ( Paeonia lactiflora Pall.) miR156e-3p in the regulation of color formation has been investigated. Firstly, P. lactiflora miR156e-3p precursor sequence (pre-miR156e-3p) was isolated. Subsequently, the overexpression vector of pre-miR156e-3p was constructed and transformed into Arabidopsis thaliana . Moreover, the medium screening, GUS staining, polymerase chain reaction (PCR) of the GUS region and real-time quantitative PCR (qRT-PCR) of miR156e-3p all confirmed that the purpose gene had been successfully transferred into Arabidopsis plants and expressed, which resulted in apparent purple lateral branches. And this change in color was caused by the improved anthocyanin accumulation. In addition, expression analysis had shown that the level of miR156e-3p transcript was increased, while transcription level of target gene squamosa promoter binding protein-like gene ( SPL1 ), encoding SPL transcription factor that negatively regulated anthocyanin accumulation, was repressed in miR156e-3p-overexpressing transgenic plants, and its downstream gene dihydroflavonol 4-reductase gene ( DFR ) that was directly involved in anthocyanin biosynthesis was strongly expressed, which resulted in anthocyanin accumulation of Arabidopsis lateral branches. These findings would improve the understanding of miRNAs regulation of color formation in P. lactiflora .

  17. Ecosystem-atmosphere exchange of CO2 in a temperate herbaceous peatland in the Sanjiang Plain of northeast China

    Science.gov (United States)

    Zhu, Xiaoyan; Song, Changchun; Swarzenski, Christopher M.; Guo, Yuedong; Zhang, Xinhow; Wang, Jiaoyue

    2015-01-01

    Northern peatlands contain a considerable share of the terrestrial carbon pool, which will be affected by future climatic variability. Using the static chamber technique, we investigated ecosystem respiration and soil respiration over two growing seasons (2012 and 2013) in a Carex lasiocarpa-dominated peatland in the Sanjiang Plain in China. We synchronously monitored the environmental factors controlling CO2 fluxes. Ecosystem respiration during these two growing seasons ranged from 33.3 to 506.7 mg CO2–C m−2 h−1. Through step-wise regression, variations in soil temperature at 10 cm depth alone explained 73.7% of the observed variance in log10(ER). The mean Q10 values ranged from 2.1 to 2.9 depending on the choice of depth where soil temperature was measured. The Q10 value at the 10 cm depth (2.9) appears to be a good representation for herbaceous peatland in the Sanjiang Plain when applying field-estimation based Q10values to current terrestrial ecosystem models due to the most optimized regression coefficient (63.2%). Soil respiration amounted to 57% of ecosystem respiration and played a major role in peatland carbon balance in our study. Emphasis on ecosystem respiration from temperate peatlands in the Sanjiang Plain will improve our basic understanding of carbon exchange between peatland ecosystem and the atmosphere.

  18. Responses of high-elevation herbaceous plant assemblages to low glacial CO₂ concentrations revealed by fossil marmot (Marmota) teeth.

    Science.gov (United States)

    McLean, Bryan S; Ward, Joy K; Polito, Michael J; Emslie, Steven D

    2014-08-01

    Atmospheric CO2 cycles of the Quaternary likely imposed major constraints on the physiology and growth of C3 plants worldwide. However, the measured record of this remains both geographically and taxonomically sparse. We present the first reconstruction of physiological responses in a late Quaternary high-elevation herbaceous plant community from the Southern Rocky Mountains, USA. We used a novel proxy-fossilized tooth enamel of yellow-bellied marmots (Marmota flaviventris)-which we developed using detailed isotopic analysis of modern individuals. Calculated C isotopic discrimination (Δ) of alpine plants was nearly 2 ‰ lower prior to the Last Glacial Maximum than at present, a response almost identical to that of nonherbaceous taxa from lower elevations. However, initial shifts in Δ aligned most closely with the onset of the late Pleistocene bipolar temperature "seesaw" rather than CO2 increase, indicating unique limitations on glacial-age high-elevation plants may have existed due to both low temperatures and low CO2. Further development of system-specific faunal proxies can help to clarify this and other plant- and ecosystem-level responses to past environmental change.

  19. Digital Gene Expression Analysis to Screen Disease Resistance-Relevant Genes from Leaves of Herbaceous Peony (Paeonia lactiflora Pall. Infected by Botrytis cinerea.

    Directory of Open Access Journals (Sweden)

    Saijie Gong

    Full Text Available Herbaceous peony (Paeonia lactiflora Pall. is a well-known traditional flower in China and is widely used for landscaping and garden greening due to its high ornamental value. However, disease spots usually appear after the flowering of the plant and may result in the withering of the plant in severe cases. This study examined the disease incidence in an herbaceous peony field in the Yangzhou region, Jiangsu Province. Based on morphological characteristics and molecular data, the disease in this area was identified as a gray mold caused by Botrytis cinerea. Based on previously obtained transcriptome data, eight libraries generated from two herbaceous peony cultivars 'Zifengyu' and 'Dafugui' with different susceptibilities to the disease were then analyzed using digital gene expression profiling (DGE. Thousands of differentially expressed genes (DEGs were screened by comparing the eight samples, and these genes were annotated using the Gene ontology (GO and Kyoto encyclopedia of genes and genomes (KEGG database. The pathways related to plant-pathogen interaction, secondary metabolism synthesis and antioxidant system were concentrated, and 51, 76, and 13 disease resistance-relevant candidate genes were identified, respectively. The expression patterns of these candidate genes differed between the two cultivars: their expression of the disease-resistant cultivar 'Zifengyu' sharply increased during the early stages of infection, while it was relatively subdued in the disease-sensitive cultivar 'Dafugui'. A selection of ten candidate genes was evaluated by quantitative real-time PCR (qRT-PCR to validate the DGE data. These results revealed the transcriptional changes that took place during the interaction of herbaceous peony with B. cinerea, providing insight into the molecular mechanisms of host resistance to gray mold.

  20. Facilitation by a Spiny Shrub on a Rhizomatous Clonal Herbaceous in Thicketization-Grassland in Northern China: Increased Soil Resources or Shelter from Herbivores

    Directory of Open Access Journals (Sweden)

    Saixiyala

    2017-05-01

    Full Text Available The formation of fertility islands by shrubs increases soil resources heterogeneity in thicketization-grasslands. Clonal plants, especially rhizomatous or stoloniferous clonal plants, can form large clonal networks and use heterogeneously distributed resources effectively. In addition, shrubs, especially spiny shrubs, may also provide herbaceous plants with protection from herbivores, acting as ‘shelters’. The interaction between pre-dominated clonal herbaceous plants and encroaching shrubs remains unclear in thicketization-grassland under grazing pressure. We hypothesized that clonal herbaceous plants can be facilitated by encroached shrubs as a ‘shelter from herbivores’ and/or as an ‘increased soil resources’ under grazing pressure. To test this hypothesis, a total of 60 quadrats were chosen in a thicket-grassland in northern China that was previously dominated by Leymus chinensis and was encroached upon by the spiny leguminous plant Caragana intermedia. The soil and plant traits beneath and outside the shrub canopies were sampled, investigated and contrasted with an enclosure. The soil organic matter, soil total nitrogen and soil water content were significantly higher in the soil beneath the shrub canopies than in the soil outside the canopies. L. chinensis beneath the shrub canopies had significantly higher plant height, single shoot biomass, leaf length and width than outside the shrub canopies. There were no significantly differences between plant growth in enclosure and outside the shrub canopies. These results suggested that under grazing pressure in a grassland undergoing thicketization, the growth of the rhizomatous clonal herbaceous plant L. chinensis was facilitated by the spiny shrub C. intermedia as a ‘shelter from herbivores’ more than through ‘increased soil resources’. We propose that future studies should focus on the community- and ecosystem-level impacts of plant clonality.

  1. How to construct the statistic network? An association network of herbaceous

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2012-06-01

    constructed network increases. Network compactness also follows the trend. In addition, as the increase of network compactness and connectance, the portion and number of negative association declines dramatically.(2 In an association (interaction network, only a few connections follow the linear relationship. Most connections follow the quasi-linear or non-linear relationships. (3 The association networks constructed from partial linear correlation and linear correlation measures are generally scale-free complex networks. The degree of these networks is power low distributed. (4 Isolated species (families, etc. are likely important in the statistic network. They are the sink species for shaping new network after a community is seriously disturbed. (5 Beween-taxa connections at higher taxonomic level are generally weaker than that at lower taxonomic level.

  2. Forest floor depth mediates understory vigor in xeric Pinus palustris ecosystems

    Science.gov (United States)

    J. Kevin Hiers; Joseph J. O' Brien; Rodney E. Will; Robert J. Mitchell

    2007-01-01

    Longleaf pine (Pinus palustris) woodlands and savannas are among the most frequently burned ecosystems in the world with fire return intervals of 1–10 years. This fire regime has maintained high levels of biodiversity in terms of both species richness and endemism. Land use changes have reduced the area of this ecosystem by .95%, and inadequate fire...

  3. Seventy years of understory development by elevation class in a New Hampshire mixed forest: management implications

    Science.gov (United States)

    William B. Leak

    2009-01-01

    New England forest managers are faced with numerous environmental issues, such as global warming, nutrient depletion, and species declines that could influence the choice of appropriate silvicultural techniques and objectives. On the Bartlett Experimental Forest, New Hampshire, 70 years of change on more than 400 remeasured cruise plots by elevation classes ranging...

  4. Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado

    OpenAIRE

    Appezzato-da-Glória, Beatriz; Cury, Graziela

    2011-01-01

    In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. ...

  5. Variability in leaf optical properties among 26 species from a broad range of habitats

    International Nuclear Information System (INIS)

    Knapp, A.K.; Carter, G.A.

    1998-01-01

    Leaves from 26 species with growth forms from annual herbs to trees were collected from open, intermediate, and shaded understory habitats in Mississippi and Kansas, USA. Leaf optical properties including reflectance, transmittance, and absorptance in visible and near infrared (NIR) wavelengths were measured along with leaf thickness and specific leaf mass (SLM). These leaf properties and internal light scattering have been reported to vary with light availability in studies that have focused on a limited number of species. Our objective was to determine whether these patterns in leaf optics and light availability were consistent when a greater number of species were evaluated. Leaf thickness and SLM varied by tenfold among species sampled, but within-habitat variance was high. Although there was a strong trend toward thicker leaves in open habitats, only SLM was significantly greater in open vs. understory habitats. In contrast, leaf optical properties were strikingly similar among habitats. Reflectance and reflectance/transmittance in the NIR were used to estimate internal light scattering and there were strong relationships (r2 0.65) between these optical properties and leaf thickness. We concluded that leaf thickness, which did not vary consistently among habitats, was the best predictor of NIR reflectance and internal light scattering. However, because carbon allocation to leaves was lower in understory species (low SLM) yet gross optical properties were similar among all habitats, the energy investment by shade leaves required to achieve optical equivalence with sun leaves was lower. Differences in leaf longevity and growth form within a habitat may help explain the lack of consistent patterns in leaf optics as the number of species sampled increases

  6. Understory vegetation in fast-growing tree plantations on savanna soils in Congo

    OpenAIRE

    Loumeto, J.J.; Huttel, Charles

    1997-01-01

    The hypothesis that tree plantations may catalyze the regeneration of natural forest biodiversity was tested through studies of floristic diversity and structure in fast-growing tree plantations in the Congo. Study sites included experimental and industrial plantations on poor sandy coastal soils near Pointe-Noire, and experimental plantations on clay soils near Loudima. The effects of plantations species, plantation age (in 6- to 20-year-old eucalypt stands), disturbance due to herbicide use...

  7. Variability in Light Use Efficiency With Changes in Vegetation Structure and Understory, Using a Temporally Changing Flux Footprint at the BERMS Old Jack Pine Site

    Science.gov (United States)

    Chasmer, L.; Barr, A.; Black, A.; Hopkinson, C.; Kljun, N.; McCaughey, H.; Treitz, P.; Shashkov, A.; Zha, T.

    2006-12-01

    Satellite remote sensing algorithms of vegetation gross primary productivity (GPP) often include a light use efficiency (LUE) term that varies depending on meteorological constraints and biome type. LUE is defined as the carbon fixed per mole of photosynthetically active radiation (PAR) absorbed by the canopy (APAR). LUE estimated using GPP from eddy covariance data is complex and changes over short time periods as the available resources (soil moisture, light, temperature, and nitrogen) vary. An understanding of the variability in LUE will improve local to regional estimates of GPP within complex vegetated land cover types using the variety of remote sensing technologies now available. This study examines variability in LUE and GPP at a mature jack pine site within the Fluxnet-Canada BERMS (Boreal Ecosystem Research and Monitoring Sites) study area using a flux footprint model (Kljun et al. 2004) and airborne lidar data (e.g. Chasmer et al. 2006). Three separate weeks of high frequency eddy covariance data are analyzed for June, July, and August 2002 to capture changes in photosynthesis and carbon uptake through the growing season with variations in precipitation and soil moisture. Footprint estimates are derived in half-hourly resolution to provide information on the spatial and temporal variation of the sources of measured C-fluxes. Airborne lidar directly samples ground topography and vegetation structure (i.e., canopy and understory height, gaps between trees, base of canopy), and may provide information on soil moisture and drainage at the ground surface via absorbed and reflected laser pulse energy. Two questions will be addressed specific to net ecosystem productivity (NEP) of the site as a whole, including parts of the ecosystem that may not be properly represented using eddy covariance techniques. These are: 1. How does C uptake and respiration spatially and temporally vary across the jack pine site? 2. How do vegetation characteristics vary with

  8. Seasonality of Overstory and Understory Fluxes in a Semi-Arid Oak Savanna: What can be Learned from Comparing Measured and Modeled Fluxes?

    Science.gov (United States)

    Raz-Yaseef, N.; Sonnentag, O.; Kobayashi, H.; Chen, J. M.; Verfaillie, J. G.; Ma, S.; Baldocchi, D. D.

    2011-12-01

    Semi-arid climates experience large seasonal and inter-annual variability in radiation and precipitation, creating natural conditions adequate to study how year-to-year changes affect atmosphere-biosphere fluxes. Especially, savanna ecosystems, that combine tree and below-canopy components, create a unique environment in which phenology dramatically changes between seasons. We used a 10-year flux database in order to define seasonal and interannual variability of climatic inputs and fluxes, and evaluate model capability to reproduce observed variability. This is based on the perception that model capability to construct the deviation, and not the average, is important in order to correctly predict ecosystem sensitivity to climate change. Our research site is a low density and low LAI (0.8) semi-arid savanna, located at Tonzi Ranch, Northern California. In this system, trees are active during the warm season (Mar - Oct), and grasses are active during the wet season (Dec - May). Measurements of carbon and water fluxes above and below the tree canopy using eddy covariance and supplementary measurements have been made since 2001. Fluxes were simulated using bio-meteorological process-oriented ecosystem models: BEPS and 3D-CAONAK. Models were partly capable of reproducing fluxes on daily scales (R2=0.66). We then compared model outputs for different ecosystem components and seasons, and found distinct seasons with high correlations while other seasons were purely represented. Comparison was much higher for ET than for GPP. The understory was better simulated than the overstory. CANOAK overestimated spring understory fluxes, probably due to the capability to directly calculated 3D radiative transfer. BEPS underestimated spring understory fluxes, following the pre-description of grass die-off. Both models underestimated peak spring overstory fluxes. During winter tree dormant, modeled fluxes were null, but occasional high fluxes of both ET and GPP were measured following

  9. Annual variation in canopy openness, air temperature and humidity inthe understory of three forested sites in southern Bahia State, Brazil

    Directory of Open Access Journals (Sweden)

    Marayana Prado Pinheiro

    2013-01-01

    Full Text Available Aiming at contributing to the knowledge of physical factors affecting community structure in Atlantic Forest remnants of southern Bahia state, Brazil, we analyzed the annual variation in the understory microclimate of a hillside forest fragment in the ‘Reserva Particular do Patrimônio Natural Serra do Teimoso’ (RST and a rustic cacao agroforestry system (Cabruca, located nearby the RST. Canopy openness (CO, air temperature (Ta, air relative humidity (RH and vapor pressure deficit (VPD data were collected between April, 2005 and April, 2006 at the base (RSTB, 340 m and the top (RSTT, 640 m of the RST and at the Cabruca (CB, 250 m. Data of rainfall, Ta, RH and VPD were also collected in an open area (OA, 270 m. The highest rainfalls (> 100 mm occurred in November, 2005 and April, 2006, whereas October, 2005 was the driest month (< 20 mm. CO ranged between 2.5 % in the CB (April, 2006 and 7.7 % in the RST (October, 2005. Low rainfall in October, 2005 affected VPDmax in all sites. Those effects were more pronounced in OA, followed by CB, RSTB and RSTT. During the period of measurements, the values of Ta, RH and VPD in CB were closer to the values measured in OA than to the values measured inside the forest.

  10. Rooting of herbaceous minicuttings of passion fruit/ Enraizamento de miniestacas herbáceas de maracujazeiro amarelo

    Directory of Open Access Journals (Sweden)

    Rudival Faquim

    2007-08-01

    Full Text Available The objective of this work was to evaluate the effect of the basal cut, leaf presence and the treament with a root suspension in the rooting of herbaceous minicuttings of yellow passion fruit. The experiment was realized in a greenhouse using minicuttings with 8 cm of lenght and two nodes, collected from yellow passion fruit seedlings. The longitudinal basal cut in the minicuttings was done until the basal node. The leaves were removed or a half of a single leaf was maintained in the apical node. The minicuttings were treated with a root suspension in water in three concentrations (0, 100 e 200 g L-1. After 58 days, the rooting percentage, the number of roots and the root dry matter produced per minicutting were determined. The entirely randomized experimental design was used in a factorial esqueme (2 x 2 x 3 with three replications. The propagation of the yellow passion fruit by herbaceous minicuttings was viable and the presence of the half of a single leaf in the apical node give a higher production of number and dry matter of roots. The basal cut was only a little favourable to the production of roots and the treatment with a root suspension did not present a benefit to the plant propagation.Este trabalho objetivou avaliar a influência do corte basal, da presença da folha e do tratamento com suspensão de raízes no enraizamento de miniestacas herbáceas de maracujazeiro amarelo. O experimento foi conduzido em casa de vegetação com miniestacas de 8 cm de comprimento e dois nós, obtidas de mudas de maracujazeiro. O corte longitudinal na base das estacas foi feito até o nó basal. Foram retiradas as folhas ou mantida a metade da folha do nó apical. As miniestacas foram tratadas com suspensão de raízes mais água nas concentrações de 0, 100 e 200 g L-1. Após 58 dias, determinou-se a porcentagem de estacas enraizadas, o número de raízes emitidas e a massa seca de raízes por estaca. O delineamento experimental utilizado foi o

  11. Identification of miRNAs Responsive to Botrytis cinerea in Herbaceous Peony (Paeonia lactiflora Pall. by High-Throughput Sequencing

    Directory of Open Access Journals (Sweden)

    Daqiu Zhao

    2015-09-01

    Full Text Available Herbaceous peony (Paeonia lactiflora Pall., one of the world’s most important ornamental plants, is highly susceptible to Botrytis cinerea, and improving resistance to this pathogenic fungus is a problem yet to be solved. MicroRNAs (miRNAs play an essential role in resistance to B. cinerea, but until now, no studies have been reported concerning miRNAs induction in P. lactiflora. Here, we constructed and sequenced two small RNA (sRNA libraries from two B. cinerea-infected P. lactiflora cultivars (“Zifengyu” and “Dafugui” with significantly different levels of resistance to B. cinerea, using the Illumina HiSeq 2000 platform. From the raw reads generated, 4,592,881 and 5,809,796 sRNAs were obtained, and 280 and 306 miRNAs were identified from “Zifengyu” and “Dafugui”, respectively. A total of 237 conserved and 7 novel sequences of miRNAs were differentially expressed between the two cultivars, and we predicted and annotated their potential target genes. Subsequently, 7 differentially expressed candidate miRNAs were screened according to their target genes annotated in KEGG pathways, and the expression patterns of miRNAs and corresponding target genes were elucidated. We found that miR5254, miR165a-3p, miR3897-3p and miR6450a might be involved in the P. lactiflora response to B. cinerea infection. These results provide insight into the molecular mechanisms responsible for resistance to B. cinerea in P. lactiflora.

  12. Effects of Inflorescence Stem Structure and Cell Wall Components on the Mechanical Strength of Inflorescence Stem in Herbaceous Peony

    Directory of Open Access Journals (Sweden)

    Qingping Geng

    2012-04-01

    Full Text Available Herbaceous peony (Paeonia lactiflora Pall. is a traditional famous flower, but its poor inflorescence stem quality seriously constrains the development of the cut flower. Mechanical strength is an important characteristic of stems, which not only affects plant lodging, but also plays an important role in stem bend or break. In this paper, the mechanical strength, morphological indices and microstructure of P. lactiflora development inflorescence stems were measured and observed. The results showed that the mechanical strength of inflorescence stems gradually increased, and that the diameter of inflorescence stem was a direct indicator in estimating mechanical strength. Simultaneously, with the development of inflorescence stem, the number of vascular bundles increased, the vascular bundle was arranged more densely, the sclerenchyma cell wall thickened, and the proportion of vascular bundle and pith also increased. On this basis, cellulose and lignin contents were determined, PlCesA3, PlCesA6 and PlCCoAOMT were isolated and their expression patterns were examined including PlPAL. The results showed that cellulose was not strictly correlated with the mechanical strength of inflorescence stem, and lignin had a significant impact on it. In addition, PlCesA3 and PlCesA6 were not key members in cellulose synthesis of P. lactiflora and their functions were also different, but PlPAL and PlCCoAOMT regulated the lignin synthesis of P. lactiflora. These data indicated that PlPAL and PlCCoAOMT could be applied to improve the mechanical strength of P. lactiflora inflorescence stem in genetic engineering.

  13. Beneath the veil: Plant growth form influences the strength of species richness-productivity relationships in forests

    Science.gov (United States)

    Oberle, B.; Grace, J.B.; Chase, J.M.

    2009-01-01

    Aim: Species richness has been observed to increase with productivity at large spatial scales, though the strength of this relationship varies among functional groups. In forests, canopy trees shade understorey plants, and for this reason we hypothesize that species richness of canopy trees will depend on macroclimate, while species richness of shorter growth forms will additionally be affected by shading from the canopy. In this study we test for differences in species richness-productivity relationships (SRPRs) among growth forms (canopy trees, shrubs, herbaceous species) in small forest plots. Location: We analysed 231 plots ranging from 34.0?? to 48.3?? N latitude and from 75.0?? to 124.2?? W longitude in the United States. Methods: We analysed data collected by the USDA Forest Inventory and Analysis program for plant species richness partitioned into different growth forms, in small plots. We used actual evapotranspiration as a macroclimatic estimate of regional productivity and calculated the area of light-blocking tissue in the immediate area surrounding plots for an estimate of the intensity of local shading. We estimated and compared SRPRs for different partitions of the species richness dataset using generalized linear models and we incorporated the possible indirect effects of shading using a structural equation model. Results: Canopy tree species richness increased strongly with regional productivity, while local shading primarily explained the variation in herbaceous plant richness. Shrub species richness was related to both regional productivity and local shading. Main conclusions: The relationship between total forest plant species richness and productivity at large scales belies strong effects of local interactions. Counter to the pattern for overall richness, we found that understorey herbaceous plant species richness does not respond to regional productivity gradients, and instead is strongly influenced by canopy density, while shrub species

  14. Environmental Assessment: 13th Street Bridge Emergency Repair and Retrofit Vandenberg Air Force Base California

    Science.gov (United States)

    2003-06-23

    project site. • Biological hazards, including vegetation (i.e., poison oak and stinging nettle ), animals (i.e., insects , spiders, and snakes), and 4-18...channel, and in dryer areas of the site. Herbaceous species in the understory include stinging nettle (Urtica dioica), California blackberry (Rubus...Nightshade FAC/FACU Poison oak Nightshade FAC/FACU Stinging nettle FACW Cockle-bur FAC+ COMMENTS Likely C. Canadensis Most E/eocharis spp

  15. Évaluation de la diversité floristique en herbacées des savanes de ...

    African Journals Online (AJOL)

    Thus, 37 species, 33 kinds and 10 families were identified in the savannah of Hyparrhenia diplandra (Hack.) Stapf and 27 species, 22 kinds and 8 families in the savannah of Loudetia simplex (Nees) CE Hubbard. Overall, the richest families in species were Poaceae, Fabaceae and the Cyperaceae. The Shannon diversity ...

  16. Net primary production of forest-forming species in climatic gradients of Eurasia

    Directory of Open Access Journals (Sweden)

    V. A. Usoltsev

    2018-04-01

    Full Text Available When using biomass and net primary production (NPP databases compiled by the authors for 6 forest-forming species in a number of 6694 and 2192 sample plots correspondingly, a system of regression models of their NPP is designed and some species-specific regularities of NPP distribution in two climatic gradients (natural zonality and climate continentality are stated. It is found that according to a zonal gradient, aboveground and total NPP in 2-needled pine and spruce-fir forests are monotonically increasing in the direction from the northern to the southern tip of the continent, while larch and birch have the maximum in the southern moderate, and aspen and poplar – in the northern moderate zone, but oak forests do not show any significant pattern. Within a single zonal belt, the aboveground and total NPP of coniferous and deciduous are monotonically decreasing in direction from the Atlantic and Pacific coasts to the continentality pole in Yakutia. The understory NPP of all the species, except oak, monotonically increase towards the subequatorial zone. For oak forests, any clear regularity is not revealed. Within a single zonal belt, when approaching continentality pole, Pinus and Quercus NPP monotonically decreases and in other species, increases. Species-specific patterns in changing the relative indices of NPP (forest stand underground NPP to aboveground one and forest understory NPP to total forest stand one in gradients of the natural zonality and climate continentality are established.

  17. Response of the Fine Root Production, Phenology, and Turnover Rate of Six Shrub Species from a Subtropical Forest to a Soil Moisture Gradient and Shading

    Science.gov (United States)

    Fu, X.; Dai, X.; Wang, H.

    2015-12-01

    Knowledge of the fine root dynamics of different life forms in forest ecosystems is critical to understanding how the overall belowground carbon cycling is affected by climate change. However, our current knowledge regarding how endogenous or exogenous factors regulate the root dynamics of understory vegetation is limited. We selected a suite of study sites representing different habitats with gradients of soil moisture and solar radiation (shading or no shading). We assessed the fine root production phenology, the total fine root production, and the turnover among six understory shrub species in a subtropical climate, and examined the responses of the fine root dynamics to gradients in the soil moisture and solar radiation. The shrubs included three evergreen species, Loropetalum chinense, Vaccinium bracteatum, and Adinandra millettii, and three deciduous species, Serissa serissoides, Rubus corchorifolius, and Lespedeza davidii. We observed that variations in the annual fine root production and turnover among species were significant in the deciduous group but not in the evergreen group. Notably, V. bracteatum and S. serissoides presented the greatest responses in terms of root phenology to gradients in the soil moisture and shading: high-moisture habitat led to a decrease and shade led to an increase in fine root production during spring. Species with smaller fine roots of the 1st+2nd-order diameter presented more sensitive responses in terms of fine root phenology to a soil moisture gradient. Species with a higher fine root nitrogen-to -carbon ratio exhibited more sensitive responses in terms of fine root annual production to shading. Soil moisture and shading did not change the annual fine root production as much as the turnover rate. The fine root dynamics of some understory shrubs varied significantly with soil moisture and solar radiation status and may be different from tree species. Our results emphasize the need to study the understory fine root dynamics

  18. Separating the effects of environment and space on tree species distribution: from population to community.

    Science.gov (United States)

    Lin, Guojun; Stralberg, Diana; Gong, Guiquan; Huang, Zhongliang; Ye, Wanhui; Wu, Linfang

    2013-01-01

    Quantifying the relative contributions of environmental conditions and spatial factors to species distribution can help improve our understanding of the processes that drive diversity patterns. In this study, based on tree inventory, topography and soil data from a 20-ha stem-mapped permanent forest plot in Guangdong Province, China, we evaluated the influence of different ecological processes at different spatial scales using canonical redundancy analysis (RDA) at the community level and multiple linear regression at the species level. At the community level, the proportion of explained variation in species distribution increased with grid-cell sizes, primarily due to a monotonic increase in the explanatory power of environmental variables. At the species level, neither environmental nor spatial factors were important determinants of overstory species' distributions at small cell sizes. However, purely spatial variables explained most of the variation in the distributions of understory species at fine and intermediate cell sizes. Midstory species showed patterns that were intermediate between those of overstory and understory species. At the 20-m cell size, the influence of spatial factors was stronger for more dispersal-limited species, suggesting that much of the spatial structuring in this community can be explained by dispersal limitation. Comparing environmental factors, soil variables had higher explanatory power than did topography for species distribution. However, both topographic and edaphic variables were highly spatial structured. Our results suggested that dispersal limitation has an important influence on fine-intermediate scale (from several to tens of meters) species distribution, while environmental variability facilitates species distribution at intermediate (from ten to tens of meters) and broad (from tens to hundreds of meters) scales.

  19. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  20. Final Scientific Report DE-FGO3-97ER62460 Stomatal Responses to CO2: A Comparison of Woody and Herbaceous Species in Arid and Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Koch, George W.

    2003-12-19

    OAK-B135 The project involved a study of a fundamental response of terrestrial vegetation to rising atmospheric carbon dioxide (CO2) concentration, namely, the change in leaf conductance to gas diffusion associated with a change in the aperture of the microscopic pores (stomata) on the surface of leaves.

  1. Dry Matter Production, Nutrient Cycled and Removed, and Soil Fertility Changes in Yam-Based Cropping Systems with Herbaceous Legumes in the Guinea-Sudan Zone of Benin

    Directory of Open Access Journals (Sweden)

    Raphiou Maliki

    2016-01-01

    Full Text Available Traditional yam-based cropping systems (shifting cultivation, slash-and-burn, and short fallow often result in deforestation and soil nutrient depletion. The objective of this study was to determine the impact of yam-based systems with herbaceous legumes on dry matter (DM production (tubers, shoots, nutrients removed and recycled, and the soil fertility changes. We compared smallholders’ traditional systems (1-year fallow of Andropogon gayanus-yam rotation, maize-yam rotation with yam-based systems integrated herbaceous legumes (Aeschynomene histrix/maize intercropping-yam rotation, Mucuna pruriens/maize intercropping-yam rotation. The experiment was conducted during the 2002 and 2004 cropping seasons with 32 farmers, eight in each site. For each of them, a randomized complete block design with four treatments and four replicates was carried out using a partial nested model with five factors: Year, Replicate, Farmer, Site, and Treatment. Analysis of variance (ANOVA using the general linear model (GLM procedure was applied to the dry matter (DM production (tubers, shoots, nutrient contribution to the systems, and soil properties at depths 0–10 and 10–20 cm. DM removed and recycled, total N, P, and K recycled or removed, and soil chemical properties (SOM, N, P, K, and pH water were significantly improved on yam-based systems with legumes in comparison with traditional systems.

  2. Coyote removal, understory cover, and survival of white-tailed deer neonates: Coyote Control and Fawn Survival

    Energy Technology Data Exchange (ETDEWEB)

    Kilgo, John C. [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Vukovich, Mark [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Ray, H. Scott [USDA Forest Service, Savannah River; New Ellenton, SC (United States); Shaw, Christopher E. [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Ruth, Charles [South Carolina Dept. of Natural Resources, Columbia, SC (United States)

    2014-09-01

    Predation by coyotes (Canis latrans) on white-tailed deer (Odocoileus virginianus) neonates has led to reduced recruitment in many deer populations in southeastern North America. This low recruitment combined with liberal antlerless deer harvest has resulted in declines in some deer populations, and consequently, increased interest in coyote population control. We investigated whether neonate survival increased after coyote removal, whether coyote predation on neonates was additive to other mortality sources, and whether understory vegetation density affected neonate survival. We monitored neonate survival for 4 years prior to (2006–2009) and 3 years during (2010–2012) intensive coyote removal on 3 32-km2 units on the United States Department of Energy’s Savannah River Site, South Carolina. We removed 474 coyotes (1.63 coyotes/km2 per unit per year), reducing coyote abundance by 78% from pre-removal levels. The best model (wi = 0.927) describing survival probability among 216 radio-collared neonates included a within-year quadratic time trend variable, date of birth, removal treatment, and a varying removal year effect. Under this model, survival differed between pre-treatment and removal periods and it differed among years during the removal period, being >100% greater than pre-treatment survival (0.228) during the first removal year (0.513), similar to pre-treatment survival during the second removal year (0.202), and intermediate during the third removal year (0.431). Despite an initial increase, the overall effect of coyote removal on neonate survival was modest. Mortality rate attributable to coyote predation was lowest during the first removal year (0.357) when survival was greatest, but the mortality rate from all other causes did not differ between the pretreatment period and any year during removals, indicating that coyote predation acted as an additive source of mortality. Survival probability was not related to

  3. Temperature regulates positively photoblastic seed germination in four ficus (moraceae) tree species from contrasting habitats in a seasonal tropical rainforest.

    Science.gov (United States)

    Chen, Hui; Cao, Min; Baskin, Jerry M; Baskin, Carol C

    2013-08-01

    Differences in seed germination responses of trees in tropical forests to temperature and light quality may contribute to their coexistence. We investigated the effects of temperature and red:far-red light (R:FR ratio) on seed germination of two gap-demanding species (Ficus hispida and F. racemosa) and two shade-tolerant species (F. altissima and F. auriculata) in a tropical seasonal rainforest in southwest China. A R:FR ratio gradient was created by filtering fluorescent light through polyester filters. Four temperature treatments were used to test the effect of temperature on seed germination of the four Ficus tree species across the R:FR gradient. Seeds of the four Ficus species were positively photoblastic. Seed germination of F. hispida and F. racemosa was not affected across the R:FR ratio gradient (0.25-1.19) at 25/35°C, but it was inhibited under low R:FR at 22/23°C. By contrast, germination percentages of F. altissima and F. auriculata were not inhibited along the entire light gradient in all temperature treatments. Differences in germination responses of Ficus species might contribute to differences in their habitat preferences. The inhibitory effect of understory temperatures in the forest might be a new mechanism that prevents positively photoblastic seeds of the gap-demanding species such as F. hispida and F. racemosa from germinating in the understory and in small canopy gaps.

  4. Organic matter quality in a soil cultivated with perennial herbaceous legumes Qualidade da matéria orgânica de um solo cultivado com leguminosas herbáceas perenes

    Directory of Open Access Journals (Sweden)

    Luciano Pasqualoto Canellas

    2004-02-01

    Full Text Available Using herbaceous legumes in agricultural systems yields great quantities of plant residues, allowing changes in soil organic matter quality and content over the years. This study was conducted on an Ultisol, at Seropédica, RJ, Brazil, to evaluate the effects of different perennial herbaceous legumes on soil organic matter quality. A factorial scheme with three replications was used to evaluate the species: forage groundnut cv. BR-14951 (Arachis pintoi, tropical kudzu (Pueraria phaseoloides, and siratro (Macroptilium atropurpureum. After the first cut, each plot was divided into two subplots; plants were cut and left on the soil surface or cut and removed. Soil samples of a closed area covered by spontaneous vegetation (mainly C3 plants or by Panicum maximum were also analysed. Samples were collected from two layers (0-5 and 5-10 cm, processed for the fractionation of organic matter and the evaluation of structural characteristics of humic acids (HA. Evaluated legumes did not change total organic carbon contents, but promoted HA accumulation in the superficial soil layer. Humic acids may be used as indicators of the management effects on soil organic fractions, because there was significant incorporation of carbon and nitrogen derived from the legume residues, even for the short experimentation time (28 months. Residue management did not modify quantitative aspects of the distribution of the humified organic matter, but promoted, however, a higher condensation degree of humic acids evaluated by the elementary composition, IR and fluorescence spectroscopy.O uso de leguminosas herbáceas em sistemas agrícolas permite o aporte de quantidades expressivas de fitomassa, possibilitando alterações no teor e na qualidade da matéria orgânica do solo ao longo dos anos. Este trabalho avalia a qualidade da matéria orgânica de um Argissolo Vermelho Amarelo localizado em Seropédica, RJ, e cultivado com diferentes espécies de leguminosas herb

  5. Long-term Seedling Dynamics of Tree Species in a Subtropical Rain Forest, Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Hao Chang-Yang

    2013-03-01

    Full Text Available Knowledge of demographical rates at seedling stage is critical for understanding forest composition and dynamics. We monitored the seedling dynamics of tree species in a subtropical rain forest in Fushan, northern Taiwan (24°45’ N, 121°35’ E during an 8-yr period (2003–2010. There were great temporal fluctuations in the seedling density, which might be largely driven by the pulses of seedling recruitment. Interspecific variation in the seedling abundance, however, was not related to the reproductive adult abundance. Previous studies showed that frequent typhoon disturbances contributed to the high canopy openness and high understory light availability at Fushan, which might benefit tree regeneration. But our results do not support this idea. Most of the newly recruited seedlings died within six months and only grew 1.55 ± 0.20 cm per year, which might be suppressed by the dense understory vegetation. Our results suggested that the majority of tree species in Fushan were recruitment limited, which might have important consequences for species coexistence. High temporal variability in recruitment density and low growth rates of seedlings emphasize the importance of long-term studies to our understandings of forest dynamics.

  6. Drivers for plant species diversity in a characteristic tropical forest landscape in Bangladesh

    DEFF Research Database (Denmark)

    Steinbauer, Manuel; Uddin, Mohammad Bela; Jentsch, Anke

    2016-01-01

    species richness and community composition along a land use intensity gradient in a forest landscape including tea gardens, tree plantations and nature reserves (Satchari Reserved Forest) based on multivariate approaches and variation partitioning. We find richness as well composition of tree...... and understory species to directly relate to a disturbance gradient that reflects protection status and elevation. This is astonishing, as the range in elevation is with 70 m really small. Topography and protection remain significant drivers of biodiversity after correcting for human disturbances. While tree...... and non-tree species richness were positively correlated, they differ considerably in their relation to other environmental or disturbance variables as well as in the spatial richness pattern. The disturbance regime particularly structures tree species richness and composition in protected areas. We...

  7. The symbiotic relationship between dominant canopy trees and soil microbes affects the nitrogen source utilization of co-existing understory trees

    Science.gov (United States)

    Iwaoka, C.; Hyodo, F.; Taniguchi, T.; Shi, W.; Du, S.; Yamanaka, N.; Tateno, R.

    2017-12-01

    The symbiotic relationship between dominant canopy trees and soil microbes such as mycorrhiza or nitrogen (N) fixer are important determinants of soil N dynamics of a forest. However, it is not known how and to what extent the symbiotic relationship of dominant canopy trees with soil microbes affect the N source of co-existing trees in forest. We measured the δ15N of surface soils (0-10 cm), leaves, and roots of the dominant canopy trees and common understory trees in an arbuscular mycorrhizal N-fixing black locust (Robinia pseudoacacia) plantation and an ectomycorrhizal oak (Quercus liaotungensis) natural forest in a China dryland. We also analyzed the soil dissolved N content in soil extracts and absorbed by ion exchange resin, and soil ammonia-oxidizer abundance using real-time PCR. The δ15N of soil and leaves were higher in the black locust forest than in the oak forest, although the δ15N of fine roots was similar in the two forests, in co-existing understory trees as well as dominant canopy trees. Accordingly, the δ15N of leaves was similar to or higher than that of fine roots in the black locust forest, whereas it was consistently lower than that of fine roots in the oak forest. In the black locust forest, the soil dissolved organic N and ammonium N contents were less abundant but the nitrate N contents in soils and absorbed by the ion exchange resin and ammonia-oxidizer abundance were greater, due to N fixation or less uptake of organic N from arbuscular mycorrhiza. In contrast, the soil dissolved organic N and ammonium N contents were more abundant in the oak forest, whereas the N content featured very low nitrate, due to ectomycorrhizal ability to access organic N. These results suggest that the main N source is nitrate N in the black locust forest, but dissolved organic N or ammonium N in the oak forest. N fixation or high N loss due to high N availability would cause high δ15N in soil and leaves in black locust forest. On the other hand, low soil N

  8. Combined use of leaf size and economics traits allows direct comparison of hydrophyte and terrestrial herbaceous adaptive strategies.

    Science.gov (United States)

    Pierce, Simon; Brusa, Guido; Sartori, Matteo; Cerabolini, Bruno E L

    2012-04-01

    Hydrophytes generally exhibit highly acquisitive leaf economics. However, a range of growth forms is evident, from small, free-floating and rapidly growing Lemniden to large, broad-leaved Nymphaeiden, denoting variability in adaptive strategies. Traits used to classify adaptive strategies in terrestrial species, such as canopy height, are not applicable to hydrophytes. We hypothesize that hydrophyte leaf size traits and economics exhibit sufficient overlap with terrestrial species to allow a common classification of plant functional types, sensu Grime's CSR theory. Leaf morpho-functional traits were measured for 61 species from 47 water bodies in lowland continental, sub-alpine and alpine bioclimatic zones in southern Europe and compared against the full leaf economics spectrum and leaf size range of terrestrial herbs, and between hydrophyte growth forms. Hydrophytes differed in the ranges and mean values of traits compared with herbs, but principal components analysis (PCA) demonstrated that both groups shared axes of trait variability: PCA1 encompassed size variation (area and mass), and PCA2 ranged from relatively dense, carbon-rich leaves to nitrogen-rich leaves of high specific leaf area (SLA). Most growth forms exhibited trait syndromes directly equivalent to herbs classified as R adapted, although Nymphaeiden ranged between C and SR adaptation. Our findings support the hypothesis that hydrophyte adaptive strategy variation reflects fundamental trade-offs in economics and size that govern all plants, and that hydrophyte adaptive strategies can be directly compared with terrestrial species by combining leaf economics and size traits.

  9. Phenotypic plasticity and population differentiation in an ongoing species invasion.

    Directory of Open Access Journals (Sweden)

    Silvia Matesanz

    Full Text Available The ability to succeed in diverse conditions is a key factor allowing introduced species to successfully invade and spread across new areas. Two non-exclusive factors have been suggested to promote this ability: adaptive phenotypic plasticity of individuals, and the evolution of locally adapted populations in the new range. We investigated these individual and population-level factors in Polygonum cespitosum, an Asian annual that has recently become invasive in northeastern North America. We characterized individual fitness, life-history, and functional plasticity in response to two contrasting glasshouse habitat treatments (full sun/dry soil and understory shade/moist soil in 165 genotypes sampled from nine geographically separate populations representing the range of light and soil moisture conditions the species inhabits in this region. Polygonum cespitosum genotypes from these introduced-range populations expressed broadly similar plasticity patterns. In response to full sun, dry conditions, genotypes from all populations increased photosynthetic rate, water use efficiency, and allocation to root tissues, dramatically increasing reproductive fitness compared to phenotypes expressed in simulated understory shade. Although there were subtle among-population differences in mean trait values as well as in the slope of plastic responses, these population differences did not reflect local adaptation to environmental conditions measured at the population sites of origin. Instead, certain populations expressed higher fitness in both glasshouse habitat treatments. We also compared the introduced-range populations to a single population from the native Asian range, and found that the native population had delayed phenology, limited functional plasticity, and lower fitness in both experimental environments compared with the introduced-range populations. Our results indicate that the future spread of P. cespitosum in its introduced range will likely be

  10. Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado.

    Science.gov (United States)

    Appezzato-da-Glória, Beatriz; Cury, Graziela

    2011-09-01

    In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.

  11. Abundance, distribution and feeding patterns of a temperate reef fish in subtidal environments of the Chilean coast: the importance of understory algal turf Abundancia, distribución y patrones alimentarios de un pez de arrecifes templados en ambientes submareales de la costa de Chile: la importancia de la capa de algas del subdosel

    Directory of Open Access Journals (Sweden)

    ÁLVARO T. PALMA

    2002-03-01

    Full Text Available Cheilodactylus variegatus is an abundant carnivorous demersal reef fish that lives in the shallow subtidal of the north-central Chilean coast. Characteristically, these environments are dominated by kelp forests of Lessonia trabeculata. This species preys on a great variety of benthic invertebrates, and shows particularly high consumption rates on amphipod crustaceans. In our study, two widely separated populations of C. variegatus were considered (central and northern Chile. Individuals that form part of these populations show considerable differences in their distribution, abundance and trophic behavior. In the northern zone, the species is abundant and both juveniles and adults are distributed along the whole bathymetric gradient. This contrasts with populations found in central Chile, which are more sparse and lack juveniles. The distribution and abundance patterns appear to be influenced mainly by the great abundance of diverse understory macroalgae in the northern subtidal, which harbors a large number of invertebrates, especially amphipods. In contrast, the understory algal abundance of the central zone is much lower, and does not show a direct relationship with the lesser abundance of amphipods. In general, C. variegatus maintains a high consumption rate on amphipods throughout its ontogeny but it includes several other prey items in later ontogenetic stages. The different understory algal assemblages, and their associated fauna, are likely to be the main factors influencing the patterns of abundance and distribution observed between these two geographically distinct fish populationsCheilodactylus variegatus es un pez demersal abundante que habita el submareal somero de la costa norte y central de Chile. Es característico de estos ambientes el estar dominados por praderas del alga Lessonia trabeculata. Esta especie incorpora en su dieta una variada gama de invertebrados bentónicos, mostrando una tasa particularmente alta de consumo de

  12. Phylogenetic Structure of Tree Species across Different Life Stages from Seedlings to Canopy Trees in a Subtropical Evergreen Broad-Leaved Forest.

    Science.gov (United States)

    Jin, Yi; Qian, Hong; Yu, Mingjian

    2015-01-01

    Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from seedlings to canopy trees, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of tree species from seedlings, saplings, treelets to canopy trees; we compare the phylogenetic turnover (measured as βNRI) between canopy trees and seedlings in forest understory with that between canopy trees and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy trees, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy trees and seedlings in forest understory is lower than that between canopy trees and seedlings in forest gaps. We conclude that tree species tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as tree stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved tree species whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate.

  13. Ecophysiological and biochemical traits of three herbaceous plants growing on the disposed coal combustion fly ash of different weathering stage

    Directory of Open Access Journals (Sweden)

    Gajić Gordana

    2013-01-01

    Full Text Available The ecophysiological and biochemical traits of Calamagrostis epigejos (Roth. Festuca rubra L. and Oenothera biennis L. growing on two fly ash lagoons of different weathering stage (L1-3 years and L2-11 years of the “Nikola Tesla- A” thermoelectric plant (Obrenovac, Serbia were studied. Species-dependent variations were observed at the L1 lagoon; the greatest vitality (Fv/Fm and Fm/Fo followed by higher photopigment and total phenolic contents were measured in O. biennis in relation to C. epigejos (p<0.001 and F. rubra (p<0.001. At the L2 site, higher vitality was found in O. biennis (p<0.001 and F. rubra (p<0.01 compared to C. epigejos. O. biennis had the highest photosynthetic capacity. The results obtained in this study indicate that all examined species maintained a level of photosynthesis that allowed them to survive and grow under the stressful conditions in ash lagoons, albeit with lower than optimal success. [Projekat Ministarstva nauke Republike Srbije, br. 173018

  14. CHEMICAL COMPOSITION OF CAATINGA POTENTIAL FORAGES SPECIES

    Directory of Open Access Journals (Sweden)

    Dynara Layza de Souza da Silva

    2015-12-01

    Full Text Available Chemical composition of some potential forages species, natives from Caatinga region, were evaluated. Samples of Macroptilium heterophyllum, Stylosanthes humilis, Rhynchosia mínima, Desmodium tortuosum Sw. Dc, Merremia aegyptia, Mimosa tenuiflora Wild, Bauhinia cheilantha and as well Macroptilium lathyroides, Caesalpinia pyramidalis and Mimosa tenuiflora hays were collected in Rio Grande do Norte Stated, during 2011 rainy season. The analyses: dry matter (DM, crude protein (CP mineral matter (MM ether extract  (EE neutral detergent fiber (NDF, acid detergent fiber (ADF, lignin (LIG, insoluble neutral detergent nitrogen, (INDN insoluble acid detergent nitrogen, (ADIN, total phenol (TF and total tannin (TT were done at Embrapa Caprinos e Ovinos in Ceará State. Plants analyzed, as expected, for tropical species, exhibited high level of cell wall constituents, high lignifications rate and revealed substantial presence of anti nutritional compounds. However, regardless of this data, the main problem, for grazing animals, is due to its xerophytes characteristics. Most of the shrubs and trees are deciduous, losing its leaves during the dry season. In addition, herbaceous presents a very rapid lifetime cycle, germinating and senescing during the brief wet season.

  15. Quantifying species recovery and conservation success to develop an IUCN Green List of Species.

    Science.gov (United States)

    Akçakaya, H Resit; Bennett, Elizabeth L; Brooks, Thomas M; Grace, Molly K; Heath, Anna; Hedges, Simon; Hilton-Taylor, Craig; Hoffmann, Michael; Keith, David A; Long, Barney; Mallon, David P; Meijaard, Erik; Milner-Gulland, E J; Rodrigues, Ana S L; Rodriguez, Jon Paul; Stephenson, P J; Stuart, Simon N; Young, Richard P

    2018-03-26

    Stopping declines in biodiversity is critically important, but it is only a first step toward achieving more ambitious conservation goals. The absence of an objective and practical definition of species recovery that is applicable across taxonomic groups leads to inconsistent targets in recovery plans and frustrates reporting and maximization of conservation impact. We devised a framework for comprehensively assessing species recovery and conservation success. We propose a definition of a fully recovered species that emphasizes viability, ecological functionality, and representation; and use counterfactual approaches to quantify degree of recovery. This allowed us to calculate a set of 4 conservation metrics that demonstrate impacts of conservation efforts to date (conservation legacy); identify dependence of a species on conservation actions (conservation dependence); quantify expected gains resulting from conservation action in the medium term (conservation gain); and specify requirements to achieve maximum plausible recovery over the long term (recovery potential). These metrics can incentivize the establishment and achievement of ambitious conservation targets. We illustrate their use by applying the framework to a vertebrate, an invertebrate, and a woody and an herbaceous plant. Our approach is a preliminary framework for an International Union for Conservation of Nature (IUCN) Green List of Species, which was mandated by a resolution of IUCN members in 2012. Although there are several challenges in applying our proposed framework to a wide range of species, we believe its further development, implementation, and integration with the IUCN Red List of Threatened Species will help catalyze a positive and ambitious vision for conservation that will drive sustained conservation action. © 2018 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  16. Clonal growth and plant species abundance.

    Science.gov (United States)

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-08-01

    Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf-height-seed) traits and by actual performance in the botanical garden. Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area - height - seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially underlying clonal growth effects on abundance. Garden

  17. Initial response to understory plant diversity and overstory tree diameter growth to a green tree retention harvest

    Science.gov (United States)

    Malcolm North; Jiquan Chen; Gordon Smith; Lucy Krakowlak; Jerry Franklin

    1996-01-01

    The increasing use of harvest techniques other than clearcutting in forests west of the Cascade mountains has created an urgent need to understand the effects of these practices on ecosystem species composition and structure. One common alternative, "green tree retention" (GTR), leaves some live trees on a harvest site to more closely mimic a moderate-...

  18. Species-specific variation in nesting and postfledging resource selection for two forest breeding migrant songbirds.

    Directory of Open Access Journals (Sweden)

    Julianna M A Jenkins

    Full Text Available Habitat selection is a fundamental component of community ecology, population ecology, and evolutionary biology and can be especially important to species with complex annual habitat requirements, such as migratory birds. Resource preferences on the breeding grounds may change during the postfledging period for migrant songbirds, however, the degree to which selection changes, timing of change, and whether all or only a few species alter their resource use is unclear. We compared resource selection for nest sites and resource selection by postfledging juvenile ovenbirds (Seiurus aurocapilla and Acadian flycatchers (Empidonax virescens followed with radio telemetry in Missouri mature forest fragments from 2012-2015. We used Bayesian discrete choice modeling to evaluate support for local vegetation characteristics on the probability of selection for nest sites and locations utilized by different ages of postfledging juveniles. Patterns of resource selection variation were species-specific. Resource selection models indicated that Acadian flycatcher habitat selection criteria were similar for nesting and dependent postfledging juveniles and selection criteria diverged when juveniles became independent from adults. After independence, flycatcher resource selection was more associated with understory foliage density. Ovenbirds differed in selection criteria between the nesting and postfledging periods. Fledgling ovenbirds selected areas with higher densities of understory structure compared to nest sites, and the effect of foliage density on selection increased as juveniles aged and gained independence. The differences observed between two sympatric forest nesting species, in both the timing and degree of change in resource selection criteria over the course of the breeding season, illustrates the importance of considering species-specific traits and postfledging requirements when developing conservation efforts, especially when foraging guilds or

  19. Influence of Trap Height and Bait Type on Abundance and Species Diversity of Cerambycid Beetles Captured in Forests of East-Central Illinois.

    Science.gov (United States)

    Schmeelk, Thomas C; Millar, Jocelyn G; Hanks, Lawrence M

    2016-08-01

    We assessed how height of panel traps above the forest floor, and the type of trap bait used, influenced the abundance and diversity of cerambycid beetles caught in forested areas of east-central Illinois. Panel traps were suspended from branches of hardwood trees at three heights above the ground: understory (∼1.5 m), lower canopy (∼6 m), and midcanopy (∼12 m). Traps were baited with either a multispecies blend of synthesized cerambycid pheromones or a fermenting bait mixture. Traps captured a total of 848 beetles of 50 species in the cerambycid subfamilies Cerambycinae, Lamiinae, Lepturinae, and Parandrinae, and one species in the closely related family Disteniidae. The species caught in highest numbers was the cerambycine Anelaphus pumilus (Newman), represented by 349 specimens. The 17 most abundant species (mean ± 1 SD: 45 ± 80 specimens per species) included 12 cerambycine and five lamiine species. Of these most abundant species, 13 (77%) were attracted to traps baited with the pheromone blend. Only the cerambycine Eburia quadrigeminata (Say) was attracted by the fermenting bait. Three species were captured primarily in understory traps, and another five species primarily in midcanopy traps. Variation among cerambycid species in their vertical distribution in forests accounted for similar overall abundances and species richness across trap height treatments. These findings suggest that trapping surveys of native communities of cerambycids, and quarantine surveillance for newly introduced exotic species, would be optimized by including a variety of trap baits and distributing traps across vertical strata of forests. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Species richness and relative species abundance of Nymphalidae (Lepidoptera in three forests with different perturbations in the North-Central Caribbean of Costa Rica

    Directory of Open Access Journals (Sweden)

    Carolyn Stephen

    2014-09-01

    Full Text Available Measurements of species richness and species abundance can have important implications for regulations and conservation. This study investigated species richness and abundance of butterflies in the family Nymphalidae at undisturbed, and disturbed habitats in Tirimbina Biological Reserve and Nogal Private Reserve, Sarapiquí, Costa Rica. Traps baited with rotten banana were placed in the canopy and the understory of three habitats: within mature forest, at a river/forest border, and at a banana plantation/forest border. In total, 71 species and 487 individuals were caught and identified during May and June 2011 and May 2013. Species richness and species abundance were found to increase significantly at perturbed habitats (p<0.0001, p<0.0001, respectively. The edge effect, in which species richness and abundance increase due to greater complementary resources from different habitats, could be one possible explanation for increased species richness and abundance. Rev. Biol. Trop. 62 (3: 919-928. Epub 2014 September 01.

  1. Physiological and morphological adaptations of herbaceous perennial legumes allow differential access to sources of varyingly soluble phosphate.

    Science.gov (United States)

    Pang, Jiayin; Yang, Jiyun; Lambers, Hans; Tibbett, Mark; Siddique, Kadambot H M; Ryan, Megan H

    2015-08-01

    The aim of this study was to investigate the capacity of three perennial legume species to access sources of varyingly soluble phosphorus (P) and their associated morphological and physiological adaptations. Two Australian native legumes with pasture potential (Cullen australasicum and Kennedia prostrata) and Medicago sativa cv. SARDI 10 were grown in sand under two P levels (6 and 40 µg P g(-1) ) supplied as Ca(H2 PO4 )2 ·H2 O (Ca-P, highly soluble, used in many fertilizers) or as one of three sparingly soluble forms: Ca10 (OH)2 (PO4 )6 (apatite-P, found in relatively young soils; major constituent of rock phosphate), C6 H6 O24 P6 Na12 (inositol-P, the most common form of organic P in soil) and FePO4 (Fe-P, a poorly-available inorganic source of P). All species grew well with soluble P. When 6 µg P g(-1) was supplied as sparingly soluble P, plant dry weight (DW) and P uptake were very low for C. australasicum and M. sativa (0.1-0.4 g DW) with the exception of M. sativa supplied with apatite-P (1.5 g). In contrast, K. prostrata grew well with inositol-P (1.0 g) and Fe-P (0.7 g), and even better with apatite-P (1.7 g), similar to that with Ca-P (1.9 g). Phosphorus uptake at 6 µg P g(-1) was highly correlated with total root length, total rhizosphere carboxylate content and total rhizosphere acid phosphatase (EC 3.1.3.2) activity. These findings provide strong indications that there are opportunities to utilize local Australian legumes in low P pasture systems to access sparingly soluble soil P and increase perennial legume productivity, diversity and sustainability. © 2014 Scandinavian Plant Physiology Society.

  2. The behavior of ash species in suspension fired biomass boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt

    While fluid bed and grate fired boilers initially was the choice of boilers used for power production from both wood and herbaceous biomass, in recent years suspension fired boilers have been increasingly used for biomass based power production. In Denmark several large pulverized fuel boilers have...... been converted from coal to biomass combustion in the last 15 years. This have included co-firing of coal and straw, up to 100% firing of wood or straw andthe use of coal ash as an additive to remedy problems with wood firing. In parallel to the commercialization of the pulverized biomass firing...... technology a long range of research studies have been conducted, to improve our understanding of the influence and behavior of biomass ash species in suspension fired boilers. The fuel ash plays a key role with respect tooptimal boiler operation and influences phenomena’s as boiler chamber deposit formation...

  3. Productivity is a poor predictor of plant species richness

    Science.gov (United States)

    Adler, Peter B.; Seabloom, Eric W.; Borer, Elizabeth T.; Hillebrand, Helmut; Hautier, Yann; Hector, Andy; Harpole, W. Stanley; O'Halloran, Lydia R.; Grace, James B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Brown, Cynthia S.; Buckley, Yvonne M.; Calabrese, Laura B.; Chu, Cheng-Jin; Cleland, Elsa E.; Collins, Scott L.; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen Ingman; Davies, Kendi F.; DeCrappeo, Nicole M.; Fay, Philip A.; Firn, Jennifer; Frater, Paul; Gasarch, Eve I.; Gruner, Daneil S.; Hagenah, Nicole; Lambers, Janneke Hille Ris; Humphries, Hope; Jin, Virginia L.; Kay, Adam D.; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Lambrinos, John G.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John W.; Mortensen, Brent; Orrock, John L.; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Wang, Gang; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

    2011-01-01

    For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity an

  4. De Novo Transcriptome Sequencing of Desert Herbaceous Achnatherum splendens (Achnatherum Seedlings and Identification of Salt Tolerance Genes

    Directory of Open Access Journals (Sweden)

    Jiangtao Liu

    2016-03-01

    Full Text Available Achnatherum splendens is an important forage herb in Northwestern China. It has a high tolerance to salinity and is, thus, considered one of the most important constructive plants in saline and alkaline areas of land in Northwest China. However, the mechanisms of salt stress tolerance in A. splendens remain unknown. Next-generation sequencing (NGS technologies can be used for global gene expression profiling. In this study, we examined sequence and transcript abundance data for the root/leaf transcriptome of A. splendens obtained using an Illumina HiSeq 2500. Over 35 million clean reads were obtained from the leaf and root libraries. All of the RNA sequencing (RNA-seq reads were assembled de novo into a total of 126,235 unigenes and 36,511 coding DNA sequences (CDS. We further identified 1663 differentially-expressed genes (DEGs between the salt stress treatment and control. Functional annotation of the DEGs by gene ontology (GO, using Arabidopsis and rice as references, revealed enrichment of salt stress-related GO categories, including “oxidation reduction”, “transcription factor activity”, and “ion channel transporter”. Thus, this global transcriptome analysis of A. splendens has provided an important genetic resource for the study of salt tolerance in this halophyte. The identified sequences and their putative functional data will facilitate future investigations of the tolerance of Achnatherum species to various types of abiotic stress.

  5. Midinfrared FT-IR as a Tool for Monitoring Herbaceous Biomass Composition and Its Conversion to Furfural

    Directory of Open Access Journals (Sweden)

    Anna Maria Raspolli Galletti

    2015-01-01

    Full Text Available A semiquantitative analysis by means of midinfrared FT-IR spectroscopy was tuned for the simultaneous determination of cellulose, hemicellulose, and lignin in industrial crops such as giant reed (Arundo donax L. and switchgrass (Panicum virgatum L.. Ternary mixtures of pure cellulose, hemicellulose, and lignin were prepared and a direct correlation area/concentration was achieved for cellulose and lignin, whereas indirect correlations were found for hemicellulose quantification. Good correspondences between the values derived from our model and those reported in the literature or obtained according to the official Van Soest method were ascertained. Average contents of 40–45% of cellulose, 20–25% of hemicellulose, and 20–25% of lignin were obtained for different samples of giant reed species. In the case of switchgrass, a content of 36% of cellulose, 28% of hemicellulose, and 26% of lignin was achieved. This analysis was also carried out on giant reed and switchgrass residues after a mild hydrolysis step carried out with dilute hydrochloric acid for the production of furfural with good yield. Reasonable compositional data were obtained, thus allowing an indirect monitoring which helps the optimization of the hydrothermal pretreatment for furfural production from hemicellulose fractions.

  6. Connecting infrared spectra with plant traits to identify species

    Science.gov (United States)

    Buitrago, Maria F.; Skidmore, Andrew K.; Groen, Thomas A.; Hecker, Christoph A.

    2018-05-01

    Plant traits are used to define species, but also to evaluate the health status of forests, plantations and crops. Conventional methods of measuring plant traits (e.g. wet chemistry), although accurate, are inefficient and costly when applied over large areas or with intensive sampling. Spectroscopic methods, as used in the food industry and mineralogy, are nowadays applied to identify plant traits, however, most studies analysed visible to near infrared, while infrared spectra of longer wavelengths have been little used for identifying the spectral differences between plant species. This study measured the infrared spectra (1.4-16.0 μm) on individual, fresh leaves of 19 species (from herbaceous to woody species), as well as 14 leaf traits for each leaf. The results describe at which wavelengths in the infrared the leaves' spectra can differentiate most effectively between these plant species. A Quadratic Discrimination Analysis (QDA) shows that using five bands in the SWIR or the LWIR is enough to accurately differentiate these species (Kappa: 0.93, 0.94 respectively), while the MWIR has a lower classification accuracy (Kappa: 0.84). This study also shows that in the infrared spectra of fresh leaves, the identified species-specific features are correlated with leaf traits as well as changes in their values. Spectral features in the SWIR (1.66, 1.89 and 2.00 μm) are common to all species and match the main features of pure cellulose and lignin spectra. The depth of these features varies with changes of cellulose and leaf water content and can be used to differentiate species in this region. In the MWIR and LWIR, the absorption spectra of leaves are formed by key species-specific traits including lignin, cellulose, water, nitrogen and leaf thickness. The connection found in this study between leaf traits, features and spectral signatures are novel tools to assist when identifying plant species by spectroscopy and remote sensing.

  7. Long-term understory vegetation dynamics and responses to ungulate exclusion in the dry forest of Mona Island

    Science.gov (United States)

    J. Rojas-Sandoval; E.J. Melendez-Ackerman; J. Fumero-Caban; M. Garcia-Bermudez; J. Sustache; S. Aragon; M. Morales-Vargas; G. Olivieri; D.S. Fernandez

    2016-01-01

    Mona Island protects one of the most important remnants of Caribbean dry forests and hosts a high diversity of rare and endangered plant and animal species. Feral ungulates (goats and pigs) were introduced to the island ~500 y ago, and their populations may be threatening the conservation of Mona Island’s native biodiversity. In this study, we used permanent fenced and...

  8. Herbivory and pollen limitation at the upper elevational range limit of two forest understory plants of eastern North America.

    Science.gov (United States)

    Rivest, Sébastien; Vellend, Mark

    2018-01-01

    Studies of species' range limits focus most often on abiotic factors, although the strength of biotic interactions might also vary along environmental gradients and have strong demographic effects. For example, pollinator abundance might decrease at range limits due to harsh environmental conditions, and reduced plant density can reduce attractiveness to pollinators and increase or decrease herbivory. We tested for variation in the strength of pollen limitation and herbivory by ungulates along a gradient leading to the upper elevational range limits of Trillium erectum (Melanthiaceae) and Erythronium americanum (Liliaceae) in Mont Mégantic National Park, Québec, Canada. In T. erectum, pollen limitation was higher at the range limit, but seed set decreased only slightly with elevation and only in one of two years. In contrast, herbivory of T. erectum increased from 60% at the upper elevational range limit. In E. americanum , we found no evidence of pollen limitation despite a significant decrease in seed set with elevation, and herbivory was low across the entire gradient. Overall, our results demonstrate the potential for relatively strong negative interactions (herbivory) and weak positive interactions (pollination) at plant range edges, although this was clearly species specific. To the extent that these interactions have important demographic consequences-highly likely for herbivory on Trillium , based on previous studies-such interactions might play a role in determining plant species' range limits along putatively climatic gradients.

  9. Patterns of species diversity and phylogenetic structure of vascular plants on the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Yan, Yujing; Yang, Xian; Tang, Zhiyao

    2013-11-01

    Large-scale patterns of species richness and the underlying mechanisms regulating these patterns have long been the central issues in biogeography and macroecology. Phylogenetic community structure is a result of combined effects of contemporary ecological interactions, environmental filtering, and evolutionary history, and it links community ecology with biogeography and trait evolution. The Qinghai-Tibetan Plateau provides a good opportunity to test the influence of contemporary climate on shaping species richness because of its unique geological history, cold climate, and high biodiversity. In this study, based on high-resolution distributions of ˜9000 vascular plant species, we explored how species richness and phylogenetic structure of vascular plants correlate with climates on the highest (and species rich) plateau on the Earth. The results showed that most of the vascular plants were distributed on the eastern part of the plateau; there was a strong association between species richness and climate, even after the effects of habitat heterogeneity were controlled. However, the responses of richness to climate remarkably depended on life-forms. Richness of woody plants showed stronger climatic associations than that of herbaceous plants; energy and water availability together regulated richness pattern of woody plants; whereas water availability predominantly regulated richness pattern of herbaceous plants. The phylogenetic structure of vascular species clustered in most areas of the plateau, suggesting that rapid speciation and environment filtering dominated the assembly of communities on the plateau. We further propose that biodiversity conservation in this area should better take into account ecological features for different life-forms and phylogenetic lineages.

  10. Uncertainty of future projections of species distributions in mountainous regions.

    Directory of Open Access Journals (Sweden)

    Ying Tang

    Full Text Available Multiple factors introduce uncertainty into projections of species distributions under climate change. The uncertainty introduced by the choice of baseline climate information used to calibrate a species distribution model and to downscale global climate model (GCM simulations to a finer spatial resolution is a particular concern for mountainous regions, as the spatial resolution of climate observing networks is often insufficient to detect the steep climatic gradients in these areas. Using the maximum entropy (MaxEnt modeling framework together with occurrence data on 21 understory bamboo species distributed across the mountainous geographic range of the Giant Panda, we examined the differences in projected species distributions obtained from two contrasting sources of baseline climate information, one derived from spatial interpolation of coarse-scale station observations and the other derived from fine-spatial resolution satellite measurements. For each bamboo species, the MaxEnt model was calibrated separately for the two datasets and applied to 17 GCM simulations downscaled using the delta method. Greater differences in the projected spatial distributions of the bamboo species were observed for the models calibrated using the different baseline datasets than between the different downscaled GCM simulations for the same calibration. In terms of the projected future climatically-suitable area by species, quantification using a multi-factor analysis of variance suggested that the sum of the variance explained by the baseline climate dataset used for model calibration and the interaction between the baseline climate data and the GCM simulation via downscaling accounted for, on average, 40% of the total variation among the future projections. Our analyses illustrate that the combined use of gridded datasets developed from station observations and satellite measurements can help estimate the uncertainty introduced by the choice of baseline

  11. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    ... of Salmonella species serotypes in relation to age and sex among children, ..... However, most antimicrobials show sufficient selective toxicity to be of value in ... salmonellosis should be given good attention (Barrow et al., 2007). To reduce ...

  12. Phytophthora niederhauserii sp. nov., a polyphagous species associated with ornamentals, fruit trees and native plants in 13 countries.

    Science.gov (United States)

    Abad, Z Gloria; Abad, Jorge A; Cacciola, Santa Olga; Pane, Antonella; Faedda, Roberto; Moralejo, Eduardo; Pérez-Sierra, Ana; Abad-Campos, Paloma; Alvarez-Bernaola, Luis A; Bakonyi, József; Józsa, András; Herrero, Maria Luz; Burgess, Treena I; Cunnington, James H; Smith, Ian W; Balci, Yilmaz; Blomquist, Cheryl; Henricot, Béatrice; Denton, Geoffrey; Spies, Chris; Mcleod, Adele; Belbahri, Lassaad; Cooke, David; Kageyama, Koji; Uematsu, Seiji; Kurbetli, Ilker; Değirmenci, Kemal

    2014-01-01

    A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia, Hungary, Israel, Italy, Japan, the Netherlands, Norway, South Africa, Spain, Taiwan, Turkey, the United Kingdom and United States in association with shrubs and herbaceous ornamentals grown mainly in greenhouses. The most prevalent hosts are English ivy (Hedera helix) and Cistus (Cistus salvifolius). The association of the species with acorn banksia (Banksia prionotes) plants in natural ecosystems in Australia, in affected vineyards (Vitis vinifera) in South Africa and almond (Prunus dulcis) trees in Spain and Turkey in addition to infection of shrubs and herbaceous ornamentals in a broad range of unrelated families are a sign of a wide ecological adaptation of the species and its potential threat to agricultural and natural ecosystems. The morphology of the persistent non-papillate ellipsoid sporangia, unique toruloid lobate hyphal swellings and amphigynous antheridia does not match any of the described species. Phylogenetic analysis based on sequences of the ITS rDNA, EF-1α, and β-tub supported that this organism is a hitherto unknown species. It is closely related to species in ITS clade 7b with the most closely related species being P. sojae. The name Phytophthora niederhauserii has been used in previous studies without the formal description of the holotype. This name is validated in this manuscript with the formal description of Phytophthora niederhauserii Z.G. Abad et J.A. Abad, sp. nov. The name is coined to honor Dr John S. Niederhauser, a notable plant pathologist and the 1990 World Food Prize laureate. © 2014 by The Mycological Society of America.

  13. The direct observation of alkali vapor species in biomass combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    French, R J; Dayton, D C; Milne, T A

    1994-01-01

    This report summarizes new data from screening various feedstocks for alkali vapor release under combustion conditions. The successful development of a laboratory flow reactor and molecular beam, mass spectrometer interface is detailed. Its application to several herbaceous and woody feedstocks, as well as a fast-pyrolysis oil, under 800 and 1,100{degrees}C batch combustion, is documented. Chlorine seems to play a large role in the facile mobilization of potassium. Included in the report is a discussion of relevant literature on the alkali problem in combustors and turbines. Highlighted are the phenomena identified in studies on coal and methods that have been applied to alkali speciation. The nature of binding of alkali in coal versus biomass is discussed, together with the implications for the ease of release. Herbaceous species and many agricultural residues appear to pose significant problems in release of alkali species to the vapor at typical combustor temperatures. These problems could be especially acute in direct combustion fired turbines, but may be ameliorated in integrated gasification combined cycles.

  14. Directed seed dispersal of Piper by Carollia perspicillata and its effect on understory plant diversity and folivory.

    Science.gov (United States)

    Salazar, Diego; Kelm, Detlev H; Salazar, Diego

    2013-11-01

    Directed dispersal occurs when seeds are differentially deposited to sites where offspring survivorship is higher than at randomly chosen sites. Traditionally, characteristics of the dispersal target sites that could increase survivorship of the dispersed plants are thought to be intrinsic to the sites. If directed dispersal is constant over extended periods of time, however, it is likely that nonrandom patterns of dispersal could modify the ecological characteristics of the target site in ways that could increase survivorship and fitness of the dispersed plants. Here we report patterns of Piper diversity (richness, equitability, and similarity) and Piper folivory within plots near natural or artificial roosts of Carollia perspicillata vs. similar plots without bat roosts. Plots with bat roosts, both natural and artificial, had significantly higher Piper species diversity. Additionally, we found that plots with a higher Piper species diversity showed less specialist folivory, higher generalist folivory, and lower total herbivore leaf damage than plots with low Piper diversity. Finally, plots with bat roosts also showed less specialist folivory, lower generalist folivory, and lower total folivory when compared to plots without roosts. We propose that long-lasting nonrandom patterns of seed dispersal can change the local ecological characteristics of target sites via changes in plant diversity, and that these changes are likely to reduce the local rates of folivory and, therefore, increase seed and adult plant survivorship.

  15. Substratos no enraizamento de estacas herbáceas de figueira oriundas da desbrota Substrates in the rooting of fig tree herbaceous cuttings originated from the sprouting

    Directory of Open Access Journals (Sweden)

    Rafael Pio

    2005-06-01

    Full Text Available Com o presente trabalho teve-se como objetivo verificar o enraizamento de estacas de figueira oriundas da desbrota, por meio da utilização de diferentes substratos. Foram coletadas estacas herbáceas de figueira 'Roxo de valinhos', aproximadamente com 10 cm de comprimento, no momento da desbrota da figueira. As estacas com apenas duas folhas e sem gema apical foram acondicionadas em bandejas de polipropileno, contendo diferentes substratos: casca de pinus®, vermiculita®, fibra de coco®, plantmax®, solo + esterco bovino (1:1 v/v e tropstrato® . Posteriormente, as estacas foram colocadas em casa-de-vegetação, com umidade e temperatura controlada. Após 50 dias, avaliaram-se a porcentagem de estacas enraizadas, brotadas e mortas, número de folhas e raízes emitidas da estaca. Os substratos fibra de coco® e plantmax® promoveram melhores resultados.The present work had the objective to verify the rooting of fig tree cuttings originating from sprouting, through the use of different substrates. Herbaceous cuttings were collected of 'Roxo de valinhos' fig tree with 10 cm of length when the sprouting was happening. The cuttings with two leaves and not of the apical bud to conditioned in polypropylene trays containing different substrates: casca de pinus®, vermiculita®, coconut fiber®, plantmax®, soil + cow mature(1:1 v/v and tropstrato® . The cuttings were placed at greenhouse, under humidity and temperature control. After 50 days, the rooting, sprouting and death cutting percentage, the number of leaves and roots of each cutting were evaluated. The substrates coconut fiber® and plantmax® promoted better results.

  16. Alien plant species list and distribution for Camdeboo National Park, Eastern Cape Province, South Africa

    Directory of Open Access Journals (Sweden)

    Mmoto L. Masubelele

    2009-09-01

    Full Text Available Protected areas globally are threatened by the potential negative impacts that invasive alien plants pose, and Camdeboo National Park (CNP, South Africa, is no exception. Alien plants have been recorded in the CNP since 1981, before it was proclaimed a national park by South African National Parks in 2005. This is the first publication of a list of alien plants in and around the CNP. Distribution maps of some of the first recorded alien plant species are also presented and discussed. To date, 39 species of alien plants have been recorded, of which 13 are invasive and one is a transformer weed. The majority of alien plant species in the park are herbaceous (39% and succulent (24% species. The most widespread alien plant species in the CNP are Atriplex inflata (= A. lindleyi subsp. inflata, Salsola tragus (= S. australis and cacti species, especially Opuntia ficus-indica. Eradication and control measures that have been used for specific problematic alien plant species are described. Conservation implications: This article represents the first step in managing invasive alien plants and includes the collation of a species list and basic information on their distribution in and around the protected area. This is important for enabling effective monitoring of both new introductions and the distribution of species already present. We present the first species list and distribution information for Camdeboo National Park.

  17. Influência da cobertura e do solo na composição florística do sub-bosque em uma floresta estacional semidecidual em Viçosa, MG, Brasil Cover and soil influence at understory of a Seasonal Tropical Forest, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    João Augusto Alves Meira-Neto

    2005-09-01

    ésio e potássio estavam correlacionados positivamente entre si e negativamente aos teores de alumínio. A cobertura revelou-se correlacionada negativamente aos teores de alumínio. Foram detectados cinco grupos de espécies segundo as preferências que apresentaram aos teores de cálcio, magnésio, potássio, alumínio e a valores de cobertura. Os teores de alumínio revelaram-se os maiores determinantes da variação encontrada na vegetação de sub-bosque. As variáveis pedológicas mostraram-se mais importantes que a variação de cobertura encontrada no sub-bosque para determinar alterações estruturais no estrato herbáceo-arbustivo.Plant-light ecological relations have been studied since the early 20th century. Light within forests has been studied since then. At community level, light environment analysis has been carried out by indirect cover measurement, but without any photogrammetric methods. This work aims to apply the canopy photogrammetric method in light environment studies of understory. Correlations among edaphic, cover and species variations were investigated to understand the understory environment. These studies were carried out in a sampled area for understory phytosociological analysis. The black and white canopy photographs were taken for cover estimation. Photographs were taken in dry and rainy seasons at 100 sample quadrats. Soil samples were taken at these quadrats. The cover average for sampled species was calculated and "t" student test was applied for testing the significance of difference between specific and populational means. Correspondence Canonical Analysis was applied to determine correlations among species, edaphic factors and cover. Cover was not significantly different in dry and rainy seasons. Only three species Heisteria silviani, Calathea brasiliensis and Psychotria conjugens, had mean cover greater than the populational mean. Other three species, Olyra micrantha, Lacistema pubescens and Pteris denticulata, had mean cover

  18. Influence of Removal of a Non-native Tree Species Mimosa caesalpiniifolia Benth. on the Regenerating Plant Communities in a Tropical Semideciduous Forest Under Restoration in Brazil

    Science.gov (United States)

    Podadera, Diego S.; Engel, Vera L.; Parrotta, John A.; Machado, Deivid L.; Sato, Luciane M.; Durigan, Giselda

    2015-11-01

    Exotic species are used to trigger facilitation in restoration plantings, but this positive effect may not be permanent and these species may have negative effects later on. Since such species can provide a marketable product (firewood), their harvest may represent an advantageous strategy to achieve both ecological and economic benefits. In this study, we looked at the effect of removal of a non-native tree species ( Mimosa caesalpiniifolia) on the understory of a semideciduous forest undergoing restoration. We assessed two 14-year-old plantation systems (modified "taungya" agroforestry system; and mixed plantation using commercial timber and firewood tree species) established at two sites with contrasting soil properties in São Paulo state, Brazil. The experimental design included randomized blocks with split plots. The natural regeneration of woody species (height ≥0.2 m) was compared between managed (all M. caesalpiniifolia trees removed) and unmanaged plots during the first year after the intervention. The removal of M. caesalpiniifolia increased species diversity but decreased stand basal area. Nevertheless, the basal area loss was recovered after 1 year. The management treatment affected tree species regeneration differently between species groups. The results of this study suggest that removal of M. caesalpiniifolia benefited the understory and possibly accelerated the succession process. Further monitoring studies are needed to evaluate the longer term effects on stand structure and composition. The lack of negative effects of tree removal on the natural regeneration indicates that such interventions can be recommended, especially considering the expectations of economic revenues from tree harvesting in restoration plantings.

  19. Slope variation and population structure of tree species from different ecological groups in South Brazil

    Directory of Open Access Journals (Sweden)

    Edmilson Bianchini

    2010-09-01

    Full Text Available Size structure and spatial arrangement of 13 abundant tree species were determined in a riparian forest fragment inParaná State, South Brazil (23"16'S and 51"01'W. The studied species were Aspidosperma polyneuron Müll. Arg., Astronium graveolens Jacq. and Gallesia integrifolia (Spreng Harms (emergent species; Alseis floribunda Schott, Ruprechtia laxiflora Meisn. and Bougainvillea spectabilis Willd. (shade-intolerant canopy species; Machaerium paraguariense Hassl, Myroxylum peruiferum L. and Chrysophyllum gonocarpum (Mart. & Eichler ex Miq. Engl. (shade-tolerant canopy species; Sorocea bonplandii (Baill. Bürger, Trichilia casaretti C. Dc, Trichilia catigua A. Juss. and Actinostemon concolor (Spreng. Müll. Arg. (understory small trees species. Height and diameter structures and basal area of species were analyzed. Spatial patterns and slope correlation were analyzed by Moran's / spatial autocorrelation coefficient and partial Mantel test, respectively. The emergent and small understory species showed the highest and the lowest variations in height, diameter and basal area. Size distribution differed among emergent species and also among canopy shade-intolerant species. The spatial pattern ranged among species in all groups, except in understory small tree species. The slope was correlated with spatial pattern for A. polyneuron, A. graveolens, A. floribunda, R. laxiflora, M. peruiferum and T. casaretti. The results indicated that most species occurredin specific places, suggesting that niche differentiation can be an important factor in structuring the tree community.Visando contribuir para o conhecimento das estratégias devida de espécies em fragmentos florestais, foram determinadas as estruturas de tamanho e espacial de 13 espécies arbóreas do remanescente de floresta ciliar no Estado do Paraná, no Sul do Brasil (23"16'S e 51"01'W. Foram analisadas as espécies: Aspidosperma polyneuron Müll. Arg., Astronium graveolens Jacq. e Gallesia

  20. Leaf anatomical traits of non-arboreal savanna species along a gradient of tree encroachment

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    Luiz Felipe Souza Pinheiro

    2017-10-01

    Full Text Available ABSTRACT In the Brazilian savanna (Cerrado of Brazil, fire suppression has transformed typical savanna formations (TS into forested savanna (FS due to the phenomenon of encroachment. Under encroachment, non-arboreal plants begin to receive less light due to greater tree density and canopy closure. Here we aim to evaluate if leaf anatomical traits of non-arboreal species differ according to the degree of tree encroachment at the Assis Ecological Station - São Paulo, Brazil. To this end, we evaluated leaf tissue thickness and specific leaf area (SLA in representative non-arboreal species occurring along a gradient of tree encroachment. Leaves of TS species showed a trend towards xeromorphism, with traits reported to facilitate survival under high luminosity, such as thick leaves, thick epidermis and mesophyll, and low SLA. In contrast, FS species exhibited mesomorphic leaves, with thin mesophyll and high SLA, which are able to capture diffuse light in denser environments. Thus, non-arboreal understory species with mesomorphic leaf traits should be favored in environments with denser vegetation in contrast to typical savanna species. The results suggest that typical non-arboreal savanna species would not survive under tree encroachment due to the low competitiveness of their leaf anatomical strategies in shady environments.

  1. Chamaedorea: diverse species in diverse habitats

    Directory of Open Access Journals (Sweden)

    1992-01-01

    Full Text Available DIVERSES ESPÈCES DANS DIVERS HABITATS. Des espèces extraordinairement diverses se trouvant dans des habitats également divers caractérisent Chamaedorea, un genre qui compte environ 90 espèces dioïques limitées aux sous-bois des forêts néo-tropicales constamment dans la pluie et les nuages du Mexique à la Bolivie et à l’Équateur. Une vaste gamme de formes biologiques, de tiges, de feuilles, d’inflorescences, de fleurs, et de fruits reflète la diversité des espèces. Bien que le genre soit plus riche en espèces dans les forêts denses et humides situées entre 800-1,500 mètres d’altitude, quelques espèces exceptionnelles se trouvent dans des forêts moins denses et/ou occasionnellement sèches, sur des substances dures ou dans d’autres habitats inhabituels. DIVERSAS ESPECIES EN DIVERSOS HÁBITATS. Especies notablemente diversas presentes en habitats igualmente diversos caracterizan a Chamaedorea, un genero de aproximadamente 90 especies dioicas limitadas al sotobosque de los bosques lluviosos y nubosos neotropicales desde Mexico hasta Bolivia y Ecuador. Una amplia gama de formas biológicas, tallos, hojas, inflorescencias, flores, y frutos refleja la diversidad de las especies. Aunque el género es más rico en especies en los bosques densos y húmedos de 800-1,500 metros de altura, unas pocas especies excepcionales ocurren en bosques abiertos o ocasionalmente secos, en substrato severo o en otros habitats extraordinarios. Remarkably diverse species occurring in equally diverse habitats characterize Chamaedorea, a genus of about 90, dioecious species restricted to the understory of neotropical rain and cloud forests from Mexico to Bolivia and Ecuador. A vast array of habits, stems, leaves, inflorescences, flowers, and fruits reflect the diversity of species. Although the genus is most species-rich in dense, moist or wet, diverse forests from 800-1,500 meters elevation, a few exceptional species occur in open and/or seasonally

  2. How does biomass distribution change with size and differ among species? An analysis for 1200 plant species from five continents.

    Science.gov (United States)

    Poorter, Hendrik; Jagodzinski, Andrzej M; Ruiz-Peinado, Ricardo; Kuyah, Shem; Luo, Yunjian; Oleksyn, Jacek; Usoltsev, Vladimir A; Buckley, Thomas N; Reich, Peter B; Sack, Lawren

    2015-11-01

    We compiled a global database for leaf, stem and root biomass representing c. 11 000 records for c. 1200 herbaceous and woody species grown under either controlled or field conditions. We used this data set to analyse allometric relationships and fractional biomass distribution to leaves, stems and roots. We tested whether allometric scaling exponents are generally constant across plant sizes as predicted by metabolic scaling theory, or whether instead they change dynamically with plant size. We also quantified interspecific variation in biomass distribution among plant families and functional groups. Across all species combined, leaf vs stem and leaf vs root scaling exponents decreased from c. 1.00 for small plants to c. 0.60 for the largest trees considered. Evergreens had substantially higher leaf mass fractions (LMFs) than deciduous species, whereas graminoids maintained higher root mass fractions (RMFs) than eudicotyledonous herbs. These patterns do not support the hypothesis of fixed allometric exponents. Rather, continuous shifts in allometric exponents with plant size during ontogeny and evolution are the norm. Across seed plants, variation in biomass distribution among species is related more to function than phylogeny. We propose that the higher LMF of evergreens at least partly compensates for their relatively low leaf area : leaf mass ratio. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  3. Determination of Tree and Understory Water Sources and Residence Times Using Stable Isotopes in a Southern Appalachian Forest

    Science.gov (United States)

    Stewart, A. N.; Knoepp, J.; Miniat, C.; Oishi, A. C.; Emanuel, R. E.

    2017-12-01

    The development of accurate hydrologic models is key to describing changes in hydrologic processes due to land use and climate change. Hydrologic models typically simplify biological processes associated with plant water uptake and transpiration, assuming that roots take up water from the same moisture pool that feeds the stream; however, this assumption is not valid for all systems. Novel combinations of climate and forest composition and structure, caused by ecosystem succession, management decisions, and climate variability, will require a better understanding of sources of water for transpiration in order to accurately estimate impact on forest water yield. Here we examine red maple (Acer rubrum), rhododendron (Rhododendron maximum), tulip poplar (Liriodendron tulipifera), and white oak (Quercus alba) trees at Coweeta Hydrologic Laboratory, a long-term hydrological and ecological research site in western NC, USA, and explore whether source water use differs by species and landscape position. We analyzed stable isotopes of water (18O and 2H) in tree cores, stream water, soil water, and precipitation using laser spectrometry and compare the isotopic composition of the various pools. We place these results in broader context using meteorological and ecophysiological data collected nearby. These findings have implications for plant water stress and drought vulnerability. They also contribute to process-based knowledge of plant water use that better captures the sensitivity of transpiration to physical and biological controls at the sub-catchment scale. This work aims to help establish novel ways to model transpiration and improve understanding of water balance, biogeochemical cycling, and transport of nutrients to streams.

  4. Native herbaceous perennials as ornamentals

    DEFF Research Database (Denmark)

    Larsen, Bjarne; Ørgaard, Marian

    2013-01-01

    Gardening with native perennials is a way to bring nature closer to urban citizens and bring up reflections on nature in a busy world. During three seasons of trialing Salvia pratensis, Dianthus deltoides, Campanula trachelium, Vincetoxicum hirundinaria, Saxifraga granulata, Plantago media and P...

  5. Nonstructural carbon dynamics are best predicted by the combination of photosynthesis and plant hydraulics during both bark beetle induced mortality and herbaceous plant response to drought

    Science.gov (United States)

    Ewers, B. E.; Mackay, D. S.; Guadagno, C.; Peckham, S. D.; Pendall, E.; Borkhuu, B.; Aston, T.; Frank, J. M.; Massman, W. J.; Reed, D. E.; Yarkhunova, Y.; Weinig, C.

    2012-12-01

    Recent work has shown that nonstructural carbon (NSC) provides both a signal and consequence of water stress in plants. The dynamics of NSC are likely not solely a result of the balance of photosynthesis and respiration (carbon starvation hypothesis) but also the availability of NSC for plant functions due to hydraulic condition. Further, plant hydraulics regulates photosynthesis both directly through stomatal conductance and indirectly through leaf water status control over leaf biochemistry. To test these hypotheses concerning NSC in response to a wide variety of plant perturbations, we used a model that combines leaf biochemical controls over photosynthesis (Farquhar model) with dynamic plant hydraulic conductance (Sperry model). This model (Terrestrial Regional Ecosystem Exchange Simulator; TREES) simulates the dynamics of NSC through a carbon budget approach that responds to plant hydraulic status. We tested TREES on two dramatically different datasets. The first dataset is from lodgepole pine and Engelmann spruce trees dying from bark beetles that carry blue-stain fungi which block xylem and cause hydraulic failure. The second data set is from Brassica rapa, a small herbaceous plant whose accessions are used in a variety of crops. The Brassica rapa plants include two parents whose circadian clock periods are different; NSC is known to provide inputs to the circadian clock likely modified by drought. Thus, drought may interact with clock control to constrain how NSC changes over the day. The Brassica rapa plants were grown in growth chamber conditions where drought was precisely controlled. The connection between these datasets is that both provide rigorous tests of our understanding of plant NSC dynamics and use similar leaf and whole plant gas exchange and NSC laboratory methods. Our results show that NSC decline (water stress. The model is able to capture this relatively small decline in NSC by limiting NSC utilization through loss of plant hydraulic

  6. Bananeiras consorciadas com leguminosas herbáceas perenes utilizadas como coberturas vivas Banana plants intercropped with perennial herbaceous legumes used as living mulches

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    José Antonio Azevedo Espindola

    2006-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a produção de bananeiras consorciadas com as leguminosas herbáceas perenes - amendoim forrageiro (Arachis pintoi, cudzu tropical (Pueraria phaseoloides e siratro (Macroptilium atropurpureum. Os tratamentos-controle consistiram em vegetação espontânea com predomínio de Panicum maximum, e vegetação espontânea com adubação nitrogenada das bananeiras. Também foi avaliado o desenvolvimento vegetativo das bananeiras. Entre as coberturas avaliadas, a vegetação espontânea e o cudzu tropical apresentaram produções maiores de biomassa; o cudzu tropical proporcionou valores maiores para quantidades de N acumulado e derivado da fixação biológica. As leguminosas amendoim forrageiro, cudzu tropical e siratro proporcionaram desenvolvimento vegetativo mais rápido nas bananeiras consorciadas. Cudzu tropical e siratro promoveram maiores valores de peso dos cachos e das pencas. O uso das leguminosas avaliadas resulta em aumento da porcentagem de cachos colhidos e redução do tempo de colheita, além de proporcionar maior produtividade, quando comparado ao uso de vegetação espontânea.The objective of this work was to evaluate the yield of banana plants intercropped with the perennial herbaceous legumes forage groundnut (Arachis pintoi, tropical kudzu (Pueraria phaseoloides and siratro (Macroptilium atropurpureum. The control treatments were spontaneous vegetation (mainly Panicum maximum and spontaneous vegetation plus nitrogen fertilizer application to banana plants. The vegetative growth of banana plants was also evaluated. Among the treatments, spontaneous vegetation and tropical kudzu promoted the highest dry matter productions; tropical kudzu had the highest amounts of accumulated and fixed N. Forage groundnut, tropical kudzu and siratro promoted the fastest vegetative growth for banana plants in this intercropped system. Tropical kudzu and siratro promoted the highest values for bunch weight and

  7. Uso de florestas secundárias por aves de sub-bosque em uma paisagem fragmentada na Amazônia central Use of secondary forests by understory birds in a fragmented landscape in central Amazonia

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    João Vitor Campos e Silva

    2012-03-01

    secondary forests that are established in the abandoned areas. The trend is an increase in secondary forests cover, resulting in a mosaic of primary forest (FP and fragments separated by an array of secondary forests (FS. In this scenario, the prediction of a massive extinction could be wrong if many species could survive in the secondary forests. To assess the importance of FS for the understory birds we sampled areas in regeneration and a continuous forest of a fragmented landscape. We conducted mist netting (24 nets/day for six consecutive days/month, for 8 months (May-November in 2009. Some forest species as do not seem to be adapted to the secondary forest environment and their occurrences are restricted to continuous forest environments. But most focal species showed no significant difference in apparent survival rates between the enviroments, suggesting that these species inhabit the secondary forest and the primary forest similarly. Because most of the matrix in fragmented landscapes are composed by secondary forests, such results highlights the conservation value that these habitats present in the long term. Thus, FS should be regarded as dynamic matrix that not only allows the movement of individuals but also function as habitat for many species typical of FP.

  8. Estudo florístico do componente herbáceo e relação com solos em áreas de caatinga do embasamento cristalino e bacia sedimentar, Petrolândia, PE, Brasil Herbaceous floristic study and relationship with soil of crystalline shield and sedimentary basin caatinga areas at Petrolândia, Pernambuco State, Brazil

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    Kleber Andrade da Silva

    2009-03-01

    Full Text Available Realizou-se um levantamento florístico em áreas de caatinga do embasamento cristalino e de bacia sedimentar, em Petrolândia, Pernambuco, objetivando-se identificar diferenças na composição, hábito e forma de vida das herbáceas entre as duas áreas. Foram coletadas amostras de solo nas profundidades de 0 a 20 cm e de 20 a 40 cm. Foram estabelecidas 100 parcelas de 1×1 m em cada área e coletadas todas as espécies herbáceas. De modo geral, o solo da área do embasamento cristalino foi mais fértil, raso, com maior capacidade de reter água e maior porcentagem de argila. Os números de famílias, gêneros e espécies das áreas da bacia sedimentar e do embasamento cristalino foram 32, 62 e 78 e 31, 53 e 69, respectivamente. A similaridade florística entre as áreas foi alta (75%. A análise de agrupamento mostrou que os arranjos florísticos entre as parcelas amostradas são mais semelhantes dentro de cada área que entre áreas, sugerindo a existência de grupos distintos. Tipo de solo parece não ser um fator decisivo na similaridade florística, hábito e proporção de forma de vida das herbáceas da vegetação da caatinga quando as áreas são próximas, mas pode influenciar a ocorrência e a freqüência de algumas espécies.Floristic surveys were carried out in two close caatinga areas, one on the crystalline shield and the other on a sedimentary basin, both at Petrolândia, Pernambuco, Brazil, with the objective of identifying differences between the two areas in composition, habit and life form of the herbaceous flora. One hundred 1×1 m plots were established in each area and all the herbaceous species were identified. Soil samples were collected at 0-20 and 20-40 cm depths. In general, the soil in the crystalline shield area was shallower, had greater clay content, with higher water holding capacity, and was more fertile. The number of families, genera and species in the sedimentary basin and crystalline shield areas were 32

  9. Spatial variation in the structure and composition of the herbaceous community in a semiarid region of northeastern Brazil Variação espacial na estrutura da comunidade herbácea em uma região semiárida do Nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    KA. Silva

    2013-02-01

    Full Text Available In the arid and semiarid environments of the world, microhabitats serve as models for the structure of vegetation communities. The goal of this study was to identify differences in the structures of the herbaceous communities growing on a crystalline substrate and those growing on a sedimentary substrate in a semiarid region of northeastern Brazil. One hundred 1 × 1 m plots were established in each area for quantitative sampling, with 69 species recorded in the crystalline area and 76 in the sedimentary area. The average plant density was higher in the sedimentary area, and average diameters and heights were greater in the crystalline area. The families and species with a high Importance Value Index (IVI and a high Mixed Ecological Value Index (MEVI differed between the areas. Of the species with high densities, only four were found in both areas. Shannon-Weiner diversity index values in the crystalline (2.96 nats/ind.-1 and sedimentary (2.89 nats/ind.-1 areas were similar. Evenness values on both substrates were also similar (0.72 and 0.71 in the crystalline and sedimentary areas, respectively. This study shows that variations in plant establishment conditions between crystalline and sedimentary areas in a semiarid region of northeastern Brazil should be considered as structure-modeling factors for the herbaceous community.Nos ambientes áridos e semiáridos do mundo, os micro-habitats modelam a estrutura das comunidades vegetais. O objetivo deste estudo foi identificar diferenças nas estruturas das comunidades herbáceas instaladas sobre o solo do embasamento cristalino e a bacia sedimentar em uma região semiárida do Nordeste do Brasil. Foram estabelecidas 100 parcelas de 1 × 1 m em cada área para amostragem das comunidades. Foram registradas 69 espécies na área cristalina e 76 na área sedimentar. A densidade média das plantas foi maior na área sedimentar e os diâmetros e as alturas médias foram maiores na área cristalina. As fam

  10. An updated checklist and key to the open-panicled species of Poa L. (Poaceae) in Peru including three new species, Poa ramoniana, Poa tayacajaensis, and Poa urubambensis

    Science.gov (United States)

    Sylvester, Steven P.; Soreng, Robert J.; Peterson, Paul M.; Sylvester, Mitsy D.P.V.

    2016-01-01

    Abstract We provide an updated checklist and key to the 30 Poa species with open panicles from Peru which includes previously circumscribed Dissanthelium and Aphanelytrum species, new taxon records, and three undescribed species. Poa compressa, Poa grisebachii, and Poa leioclada are recorded from Peru for the first time. A number of species are placed in synonymy: Poa carazensis, Poa ferreyrae and Poa tovarii are synonymized under the name Poa fibrifera; Poa adusta (tentatively) and Poa pilgeri are synonymized under Poa candamoana; Poa superata is synonymized under Poa grisebachii; and Poa paramoensis is synonymized under Poa huancavelicae. Included within this treatment are three new species, Poa ramoniana, Poa tayacajaensis and Poa urubambensis, which are described and illustrated. Poa ramoniana, found growing near lakes in high elevation Puna grasslands of Junín, is similar to a small form of Poa glaberrima, but differs in having rhizomes and growing to only 5 cm tall. Poa tayacajaensis, found from shrublands on Andean slopes of Huancavelica and Huánuco, bears similarities to Poa aequatoriensis but differs in having shorter lemmas which are pubescent between the veins, densely scabrous sheaths with smooth, glabrous throats, and shorter ligules. Poa urubambensis, a common element of the undisturbed Polylepis forest understory of the Cordillera Urubamba, Cusco, is distinct from all other members of open-panicled Poa’s by having glabrous lemmas with a smooth and glabrous callus, and notably small anthers. The type material for the name Poa adusta is discussed and a lectotype is selected. PMID:27489489

  11. Florística e fitossociologia do estrato herbáceo e da regeneração arbórea de trecho de floresta secundária em Juquitiba, SP, Brasil

    Directory of Open Access Journals (Sweden)

    Rodrigo Trassi Polisel

    2011-01-01

    Full Text Available The aim of this work was to study the composition and structure of the herbaceous and tree regeneration community and to evaluate the negative consequences of these descriptors of the community which were generated from the record of area use (deforestation to produce vegetal coal. This study was undertaken in a 40-year-old secondary Dense Ombrophilous Forest in Juquitiba, SP, and the herb layer was defined by the presence of herbs, sub-shrubs, shrubs and vine species. Tree regeneration was defined by the presence of palms and tree species, from 10 cm to 1.30 m of height. Fourty-eight samples of 2 x 2 m were located systematically along the delineated area, a total of 192 m2. 130 species were registered, most of which were composed of tree species in regeneration (85, followed by herbs (17. Half of the total importance value was occupied by 11 tree species, besides one of each life habit surveyed. The presence of ruderal species and a low number of herbaceous species typical of understory show that the area has suffered several damages. Furthermore, the floristic diversity of the herbaceous layer is mainly due to the high richness of the trees species that are in regeneration and not to the typical species of this layer.

  12. Competition and facilitation structure plant communities under nurse tree canopies in extremely stressful environments.

    Science.gov (United States)

    Al-Namazi, Ali A; El-Bana, Magdy I; Bonser, Stephen P

    2017-04-01

    Nurse plant facilitation in stressful environments can produce a