WorldWideScience

Sample records for ecosystem production plant

  1. Net ecosystem production in a Little Ice Age moraine: the role of plant functional traits

    Science.gov (United States)

    Varolo, E.; Zanotelli, D.; Tagliavini, M.; Zerbe, S.; Montagnani, L.

    2015-07-01

    Current glacier retreat allows vast mountain ranges available for vegetation establishment and growth. Little is known about the effective carbon (C) budget of these new ecosystems and how the presence of different vegetation communities, characterized by their specific physiology and life forms influences C fluxes. In this study, using a comparative analysis of the C fluxes of two contrasting vegetation types, we intend to evaluate if the different physiologies of the main species have an effect on Ecosystem Respiration (Reco), Gross Primary Production (GPP), annual cumulated Net Ecosystem Exchange (NEE), and long-term carbon accumulation in soil. The NEE of two plant communities present on a Little Ice Age moraine in the Matsch glacier forefield (Alps, Italy) was measured over two growing seasons. They are a typical C3 grassland, dominated by Festuca halleri All. and a community dominated by CAM rosettes Sempervivum montanum L. on rocky soils. Using transparent and opaque chambers, we extrapolated the ecophysiological responses to the main environmental drivers and performed the partition of NEE into Reco and GPP. Soil samples were collected from the same site to measure long-term C accumulation in the ecosystem. The two communities showed contrasting GPP but similar Reco patterns and as a result significantly different in NEE. The grassland acted mainly as a carbon sink with a total cumulated value of -46.4 ± 35.5 g C m-2 NEE while the plots dominated by the CAM rosettes acted as a source with 31.9 ± 22.4 g C m-2. In spite of the NEE being different in the two plant communities, soil analysis did not reveal significant differences in carbon accumulation. Grasslands showed 1.76 ± 0.12 kg C m-2, while CAM rosettes showed 2.06 ± 0.23 kg C m-2. This study demonstrates that carbon dynamics of two vegetation communities can be distinct even though the growing environment is similar. The physiological traits of the dominant species determine large differences in

  2. Linkages of plant stoichiometry to ecosystem production and carbon fluxes with increasing nitrogen inputs in an alpine steppe.

    Science.gov (United States)

    Peng, Yunfeng; Li, Fei; Zhou, Guoying; Fang, Kai; Zhang, Dianye; Li, Changbin; Yang, Guibiao; Wang, Guanqin; Wang, Jun; Yang, Yuanhe

    2017-12-01

    Unprecedented levels of nitrogen (N) have entered terrestrial ecosystems over the past century, which substantially influences the carbon (C) exchange between the atmosphere and biosphere. Temperature and moisture are generally regarded as the major controllers over the N effects on ecosystem C uptake and release. N-phosphorous (P) stoichiometry regulates the growth and metabolisms of plants and soil organisms, thereby affecting many ecosystem C processes. However, it remains unclear how the N-induced shift in the plant N:P ratio affects ecosystem production and C fluxes and its relative importance. We conducted a field manipulative experiment with eight N addition levels in a Tibetan alpine steppe and assessed the influences of N on aboveground net primary production (ANPP), gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem exchange (NEE); we used linear mixed-effects models to further determine the relative contributions of various factors to the N-induced changes in these parameters. Our results showed that the ANPP, GEP, ER, and NEE all exhibited nonlinear responses to increasing N additions. Further analysis demonstrated that the plant N:P ratio played a dominate role in shaping these C exchange processes. There was a positive relationship between the N-induced changes in ANPP (ΔANPP) and the plant N:P ratio (ΔN:P), whereas the ΔGEP, ΔER, and ΔNEE exhibited quadratic correlations with the ΔN:P. In contrast, soil temperature and moisture were only secondary predictors for the changes in ecosystem production and C fluxes along the N addition gradient. These findings highlight the importance of plant N:P ratio in regulating ecosystem C exchange, which is crucial for improving our understanding of C cycles under the scenarios of global N enrichment. © 2017 John Wiley & Sons Ltd.

  3. Responses of plant community composition and biomass production to warming and nitrogen deposition in a temperate meadow ecosystem.

    Science.gov (United States)

    Zhang, Tao; Guo, Rui; Gao, Song; Guo, Jixun; Sun, Wei

    2015-01-01

    Climate change has profound influences on plant community composition and ecosystem functions. However, its effects on plant community composition and biomass production are not well understood. A four-year field experiment was conducted to examine the effects of warming, nitrogen (N) addition, and their interactions on plant community composition and biomass production in a temperate meadow ecosystem in northeast China. Experimental warming had no significant effect on plant species richness, evenness, and diversity, while N addition highly reduced the species richness and diversity. Warming tended to reduce the importance value of graminoid species but increased the value of forbs, while N addition had the opposite effect. Warming tended to increase the belowground biomass, but had an opposite tendency to decrease the aboveground biomass. The influences of warming on aboveground production were dependent upon precipitation. Experimental warming had little effect on aboveground biomass in the years with higher precipitation, but significantly suppressed aboveground biomass in dry years. Our results suggest that warming had indirect effects on plant production via its effect on the water availability. Nitrogen addition significantly increased above- and below-ground production, suggesting that N is one of the most important limiting factors determining plant productivity in the studied meadow steppe. Significant interactive effects of warming plus N addition on belowground biomass were also detected. Our observations revealed that environmental changes (warming and N deposition) play significant roles in regulating plant community composition and biomass production in temperate meadow steppe ecosystem in northeast China.

  4. Antecedent Moisture and Biological Inertia as Predictors of Plant and Ecosystem Productivity in Arid and Semiarid Systems

    Science.gov (United States)

    Ogle, K.

    2011-12-01

    Many plant and ecosystem processes in arid and semiarid systems may be affected by antecedent environmental conditions (e.g., precipitation patterns, soil water availability, temperature) that integrate over past days, weeks, months, seasons, or years. However, the importance of such antecedent exogenous effects relative to conditions occurring at the time of the observed process is relatively unexplored. Even less is known about the potential importance of antecedent endogenous effects that describe the influence of past ecosystem states on the current ecosystem state; e.g., how is current ecosystem productivity related to past productivity patterns? We hypothesize that incorporation of antecedent exogenous and endogenous factors can improve our predictive understanding of many plant and ecosystem processes, especially in arid and semiarid ecosystems. Furthermore, the common approach to quantifying the effects of antecedent (exogenous) variables relies on arbitrary, deterministic definitions of antecedent variables that (1) may not accurately describe the role of antecedent conditions and (2) ignore uncertainty associated with applying deterministic definitions. In this study, we employ a stochastic framework for (1) computing the antecedent variables that estimates the relative importance of conditions experienced each time unit into the past, also providing insight into potential lag responses, and (2) estimating the effect of antecedent factors on the response variable of interest. We employ this approach to explore the potential roles of antecedent exogenous and endogenous influences in three settings that illustrate the: (1) importance of antecedent precipitation for net primary productivity in the shortgrass steppe in northern Colorado, (2) dependency of tree growth on antecedent precipitation and past growth states for pinyon growing in western Colorado, and (3) influence of antecedent soil water and prior root status on observed root growth in the Mojave

  5. Plant, microbial and ecosystem carbon use efficiencies interact to stabilize microbial growth as a fraction of gross primary production.

    Science.gov (United States)

    Sinsabaugh, Robert L; Moorhead, Daryl L; Xu, Xiaofeng; Litvak, Marcy E

    2017-06-01

    The carbon use efficiency of plants (CUE a ) and microorganisms (CUE h ) determines rates of biomass turnover and soil carbon sequestration. We evaluated the hypothesis that CUE a and CUE h counterbalance at a large scale, stabilizing microbial growth (μ) as a fraction of gross primary production (GPP). Collating data from published studies, we correlated annual CUE a , estimated from satellite imagery, with locally determined soil CUE h for 100 globally distributed sites. Ecosystem CUE e , the ratio of net ecosystem production (NEP) to GPP, was estimated for each site using published models. At the ecosystem scale, CUE a and CUE h were inversely related. At the global scale, the apparent temperature sensitivity of CUE h with respect to mean annual temperature (MAT) was similar for organic and mineral soils (0.029°C -1 ). CUE a and CUE e were inversely related to MAT, with apparent sensitivities of -0.009 and -0.032°C -1 , respectively. These trends constrain the ratio μ : GPP (= (CUE a  × CUE h )/(1 - CUE e )) with respect to MAT by counterbalancing the apparent temperature sensitivities of the component processes. At the ecosystem scale, the counterbalance is effected by modulating soil organic matter stocks. The results suggest that a μ : GPP value of c. 0.13 is a homeostatic steady state for ecosystem carbon fluxes at a large scale. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  6. Photochemically induced carbon dioxide production as a mechanism for carbon loss from plant litter in arid ecosystems

    Science.gov (United States)

    Brandt, L. A.; Bohnet, C.; King, J. Y.

    2009-06-01

    We investigated the potential for abiotic mineralization to carbon dioxide (CO2) via photodegradation to account for carbon (C) loss from plant litter under conditions typical of arid ecosystems. We exposed five species of grass and oak litter collected from arid and mesic sites to a factorial design of ultraviolet (UV) radiation (UV pass, UV block), and sterilization under dry conditions in the laboratory. UV pass treatments produced 10 times the amount of CO2 produced in UV block treatments. CO2 production rates were unaffected by litter chemistry or sterilization. We also exposed litter to natural solar radiation outdoors on clear, sunny days close to the summer solstice at midlatitudes and found that UV radiation (280-400 nm) accounted for 55% of photochemically induced CO2 production, while shortwave visible radiation (400-500 nm) accounted for 45% of CO2 production. Rates of photochemically induced CO2 production on a per-unit-mass basis decreased with litter density, indicating that rates depend on litter surface area. We found no evidence for leaching, methane production, or facilitation of microbial decomposition as alternative mechanisms for significant photochemically induced C loss from litter. We conclude that abiotic mineralization to CO2 is the primary mechanism by which C is lost from litter during photodegradation. We estimate that CO2 production via photodegradation could be between 1 and 4 g C m-2 a-1 in arid ecosystems in the southwestern United States. Taken together with low levels of litter production in arid systems, photochemical mineralization to CO2 could account for a significant proportion of annual carbon loss from litter in arid ecosystems.

  7. Trade-offs Between Electricity Production from Small Hydropower Plants and Ecosystem Services in Alpine River Basins

    Science.gov (United States)

    Meier, Philipp; Schwemmle, Robin; Viviroli, Daniel

    2015-04-01

    The need for a reduction in greenhouse gas emissions and the decision to phase out nuclear power plants in Switzerland and Germany increases pressure to develop the remaining hydropower potential in Alpine catchments. Since most of the potential for large reservoirs is already exploited, future development focusses on small run-of-the-river hydropower plants (SHP). Being considered a relatively environment-friendly electricity source, investment in SHP is promoted through subsidies. However, SHP can have a significant impact on riverine ecosystems, especially in the Alpine region where residual flow reaches tend to be long. An increase in hydropower exploitation will therefore increase pressure on ecosystems. While a number of studies assessed the potential for hydropower development in the Alps, two main factors were so far not assessed in detail: (i) ecological impacts within a whole river network, and (ii) economic conditions under which electricity is sold. We present a framework that establishes trade-offs between multiple objectives regarding environmental impacts, electricity production and economic evaluation. While it is inevitable that some ecosystems are compromised by hydropower plants, the context of these impacts within a river network should be considered when selecting suitable sites for SHP. From an ecological point of view, the diversity of habitats, and therefore the diversity of species, should be maintained within a river basin. This asks for objectives that go beyond lumped parameters of hydrological alteration, but also consider habitat diversity and the spatial configuration. Energy production in run-of-the-river power plants depends on available discharge, which can have large fluctuations. In a deregulated electricity market with strong price variations, an economic valuation should therefore be based on the expected market value of energy produced. Trade-off curves between different objectives can help decision makers to define policies

  8. Leaf bacterial diversity mediates plant diversity and ecosystem function relationships.

    Science.gov (United States)

    Laforest-Lapointe, Isabelle; Paquette, Alain; Messier, Christian; Kembel, Steven W

    2017-06-01

    Research on biodiversity and ecosystem functioning has demonstrated links between plant diversity and ecosystem functions such as productivity. At other trophic levels, the plant microbiome has been shown to influence host plant fitness and function, and host-associated microbes have been proposed to influence ecosystem function through their role in defining the extended phenotype of host organisms However, the importance of the plant microbiome for ecosystem function has not been quantified in the context of the known importance of plant diversity and traits. Here, using a tree biodiversity-ecosystem functioning experiment, we provide strong support for the hypothesis that leaf bacterial diversity is positively linked to ecosystem productivity, even after accounting for the role of plant diversity. Our results also show that host species identity, functional identity and functional diversity are the main determinants of leaf bacterial community structure and diversity. Our study provides evidence of a positive correlation between plant-associated microbial diversity and terrestrial ecosystem productivity, and a new mechanism by which models of biodiversity-ecosystem functioning relationships can be improved.

  9. Is an ecosystem services-based approach developed for setting specific protection goals for plant protection products applicable to other chemicals?

    Science.gov (United States)

    Maltby, Lorraine; Jackson, Mathew; Whale, Graham; Brown, A Ross; Hamer, Mick; Solga, Andreas; Kabouw, Patrick; Woods, Richard; Marshall, Stuart

    2017-02-15

    Clearly defined protection goals specifying what to protect, where and when, are required for designing scientifically sound risk assessments and effective risk management of chemicals. Environmental protection goals specified in EU legislation are defined in general terms, resulting in uncertainty in how to achieve them. In 2010, the European Food Safety Authority (EFSA) published a framework to identify more specific protection goals based on ecosystem services potentially affected by plant protection products. But how applicable is this framework to chemicals with different emission scenarios and receptor ecosystems? Four case studies used to address this question were: (i) oil refinery waste water exposure in estuarine environments; (ii) oil dispersant exposure in aquatic environments; (iii) down the drain chemicals exposure in a wide range of ecosystems (terrestrial and aquatic); (iv) persistent organic pollutant exposure in remote (pristine) Arctic environments. A four-step process was followed to identify ecosystems and services potentially impacted by chemical emissions and to define specific protection goals. Case studies demonstrated that, in principle, the ecosystem services concept and the EFSA framework can be applied to derive specific protection goals for a broad range of chemical exposure scenarios. By identifying key habitats and ecosystem services of concern, the approach offers the potential for greater spatial and temporal resolution, together with increased environmental relevance, in chemical risk assessments. With modifications including improved clarity on terminology/definitions and further development/refinement of the key concepts, we believe the principles of the EFSA framework could provide a methodical approach to the identification and prioritization of ecosystems, ecosystem services and the service providing units that are most at risk from chemical exposure. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights

  10. Genetically modified soybean plants and their ecosystem

    Directory of Open Access Journals (Sweden)

    Milošević Mirjana B.

    2004-01-01

    Full Text Available Transgenic plants are developed by introgressing new genes using methods of molecular genetics and genetic engineering. The presence of these genes in plant genome is identified on the basis of specific oligonucleotides primers, and the use of PCR (Polymerase Chain Reaction and DNA fragments multiplication. Genetically modified plants such as soybean constitute a newly created bioenergetic potential whose gene expression can cause disturbance of the biological balance ecosystem, soil structure and soil microbiological activity. Genetically modified plants may acquire monogenic or polygenic traits causing genetic and physiological changes in these plants, which may elicit a certain reaction of the environment including changes of microbiological composition of soil rhizosphere. The aim of introgressing genes for certain traits into a cultivated plant is to enhance its yield and intensify food production. There are more and more genetically modified plant species such as soybean, corn, potato, rice and others and there is a pressure to use them as human food and animal feed. Genetically modified soybean plants with introgressed gene for resistance to total herbicides, such as Round-up, are more productive than non-modified herbicide-sensitive soybeans.

  11. Forests planted for ecosystem restoration or conservation.

    Science.gov (United States)

    Constance A. Harrington

    1999-01-01

    Although the phrase, "planting for ecosystem restoration," is of recent origin, many of the earliest large-scale tree plantings were made for what we now refer to as "'restoration" or "conservation" goals. Forest restoration activities may be needed when ecosystems are disturbed by either natural or anthropogenic forces. Disturbances...

  12. Biodiversity increases the resistance of ecosystem productivity to climate extremes.

    Science.gov (United States)

    Isbell, Forest; Craven, Dylan; Connolly, John; Loreau, Michel; Schmid, Bernhard; Beierkuhnlein, Carl; Bezemer, T Martijn; Bonin, Catherine; Bruelheide, Helge; de Luca, Enrica; Ebeling, Anne; Griffin, John N; Guo, Qinfeng; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtěch; Manning, Pete; Meyer, Sebastian T; Mori, Akira S; Naeem, Shahid; Niklaus, Pascal A; Polley, H Wayne; Reich, Peter B; Roscher, Christiane; Seabloom, Eric W; Smith, Melinda D; Thakur, Madhav P; Tilman, David; Tracy, Benjamin F; van der Putten, Wim H; van Ruijven, Jasper; Weigelt, Alexandra; Weisser, Wolfgang W; Wilsey, Brian; Eisenhauer, Nico

    2015-10-22

    It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities. However, subsequent experimental tests produced mixed results. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16-32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.

  13. Bee community as a source of energy in the production of food, honey-plants in the ecosystem of Croatian Forests' hunting grounds.

    Science.gov (United States)

    Tucak, Zvonimir; Beuk, Darko; Jumić, Vlado; Tusek, Tatjana; Vladimir-Knezević, Sanda; Tolusić, Zdravko; Skrivanko, Mario; Konjarović, Anastazija; Aladić, Krunoslav; Cupurdija, Edita

    2009-12-01

    In addition to the process of photosynthesis, the bee community is the main source of energy in food production, honey-plants used by game and people in the hunting grounds ecosystem. It is a well-known fact that thousands of plant species depend on the presence of bee communities (pollination, fertilization). In this paper we studied the presence of the bee community in the hunting grounds of Croatian Forests, and their influence on the number of game (wild pigs), as well as the quality of honey, honey plants in the hunting grounds used by people and game. We established the total number of game (wild boars). The honey quality parameters were determined using the Harmonised methods of the European Honey (Bogdanov et al., 1997) and the pollen analysis by were conducted according to Harmonised methods of melissopalynology (Von der Ohe et al., 2004). Research results indicate that the presence of the bee community influences the number of wild boars from 3-18%, and the quality of honey is in line with the European and world standards. The SAS/STAT package was used for the statistical analysis (SAS Institute Inc., 2000). The significance of the differences among the groups was determined by Duncan test.

  14. Rehabilitation of saline ecosystems through cultivation of salt tolerant plants

    International Nuclear Information System (INIS)

    Abdul, R.; Mahmood, K.

    2012-01-01

    In Pakistan, salt-affected regions have been drastically disturbed by unchecked activities of local populations. Removal of deep-rooted perennials and overgrazing destroy the native vegetation leading to rapid desertification. Shallow-rooted agricultural crops are grown on marginal soils on limited area that is not enough with respect to the spread of salinity problem. Sustainable restoration of these ecosystems requires a large scale integration of perennial plants (trees, shrubs and herbs) back in to farming systems. However, selenization processes continue because the available options for cultivation of perennial plants prove less profitable than agricultural crops. This study relates to resort the salt-affected lands for plant production and develop a technology for sustainable saline ecosystem. Plants, having salt tolerance potential, have been identified and introduced on salt-affected wastelands to develop a sustainable ecosystem with increased productivity. The biomass so produced can be used directly as forage, fuel, and even as food or feed. In addition, fish aquaculture, and some value-added products make this ecosystem more sustainable. This technology is practically demonstrated at Biosaline Research Station of Nuclear Institute for Agriculture and Biology (NIAB), Pakka Anna, Faisalabad, Pakistan. The marginally saline soils and wastelands ameliorated as a result of growing salt tolerant perennials can also be used for growing salt tolerant cultivars of conventional crops like wheat, barley and mustard. So, through proper management the saline ecosystem can become economical and profitable. (author)

  15. Coastal ecosystems, productivity and ecosystem protection: Coastal ecosystem management

    International Nuclear Information System (INIS)

    Ngoile, M.A.K.; Horrill, C.J.

    1993-01-01

    The coastal zone is a complex ecosystem under the influence of physical, chemical and biological processes. Under natural conditions these processes interact and maintain an equilibrium in the coastal ecosystem. Man makes a variety of important uses of coastal resources, ranging from harvesting of living resources, extraction of nonliving resources, and recreation, to the disposal of wastes. Man's extensive use of the oceans introduces factors which bring about an imbalance in the natural processes, and may result in harmful and hazardous effects to life hindering further use. Man's pressure on the resources of the coastal zone is already manifest and will increase manifold. This calls for an immediate solution to the protection and sustainable use of coastal resources. The current sectorized approach to the management of human activities will not solve the problem because the different resources of the coastal zone interact in such a manner that disturbances in one cause imbalance in the others. This is further complicated by the sectorized approach to research and limited communication between policy makers, managers, and scientists. This paper discusses strategies for managing coastal-resources use through an integrated approach. The coastal zone is presented as a unified ecosystem in equilibrium and shows that man's extensive use of the coastal resources destabilizes this equilibrium. Examples from the East Africa Region are presented. 15 refs, 2 figs, 3 tabs

  16. Chlorophyll fluorescence is a rigorous, high throughput tool to analyze the impacts of genotype, species, and stress on plant and ecosystem productivity

    Science.gov (United States)

    Ewers, B. E.; Pleban, J. R.; Aston, T.; Beverly, D.; Speckman, H. N.; Hosseini, A.; Bretfeld, M.; Edwards, C.; Yarkhunova, Y.; Weinig, C.; Mackay, D. S.

    2017-12-01

    . High throughput handheld or drone-based measurements of chlorophyll fluorescence provide high quality, quantitative data that can be used to not only connect genotype to phenotype but also quantify how vastly different plant species and genotypes respond to stress and change ecosystem productivity.

  17. Methane Production by Seagrass Ecosystems in the Red Sea

    KAUST Repository

    Garcias Bonet, Neus

    2017-11-07

    Atmospheric methane (CH) is the second strongest greenhouse gas and it is emitted to the atmosphere naturally by different sources. It is crucial to define the dimension of these natural emissions in order to forecast changes in atmospheric CH mixing ratio in future scenarios. However, CH emissions by seagrass ecosystems in shallow marine coastal systems have been neglected although their global extension. Here we quantify the CH production rates of seagrass ecosystems in the Red Sea. We measured changes in CH concentration and its isotopic signature by cavity ring-down spectroscopy on chambers containing sediment and plants. We detected CH production in all the seagrass stations with an average rate of 85.09 ± 27.80 μmol CH m d. Our results show that there is no seasonal or daily pattern in the CH production rates by seagrass ecosystems in the Red Sea. Taking in account the range of global estimates for seagrass coverage and the average seagrass CH production, the global CH production and emission by seagrass ecosystems could range from 0.09 to 2.7 Tg yr. Because CH emission by seagrass ecosystems had not been included in previous global CH budgets, our estimate would increase the contribution of marine global emissions, hitherto estimated at 9.1 Tg yr, by about 30%. Thus, the potential contribution of seagrass ecosystems to marine CH emissions provides sufficient evidence of the relevance of these fluxes as to include seagrass ecosystems in future assessments of the global CH budgets.

  18. Methane Production by Seagrass Ecosystems in the Red Sea

    KAUST Repository

    Garcias Bonet, Neus; Duarte, Carlos M.

    2017-01-01

    Atmospheric methane (CH) is the second strongest greenhouse gas and it is emitted to the atmosphere naturally by different sources. It is crucial to define the dimension of these natural emissions in order to forecast changes in atmospheric CH mixing ratio in future scenarios. However, CH emissions by seagrass ecosystems in shallow marine coastal systems have been neglected although their global extension. Here we quantify the CH production rates of seagrass ecosystems in the Red Sea. We measured changes in CH concentration and its isotopic signature by cavity ring-down spectroscopy on chambers containing sediment and plants. We detected CH production in all the seagrass stations with an average rate of 85.09 ± 27.80 μmol CH m d. Our results show that there is no seasonal or daily pattern in the CH production rates by seagrass ecosystems in the Red Sea. Taking in account the range of global estimates for seagrass coverage and the average seagrass CH production, the global CH production and emission by seagrass ecosystems could range from 0.09 to 2.7 Tg yr. Because CH emission by seagrass ecosystems had not been included in previous global CH budgets, our estimate would increase the contribution of marine global emissions, hitherto estimated at 9.1 Tg yr, by about 30%. Thus, the potential contribution of seagrass ecosystems to marine CH emissions provides sufficient evidence of the relevance of these fluxes as to include seagrass ecosystems in future assessments of the global CH budgets.

  19. Plant species richness and ecosystem multifunctionality in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Quero, Jose L.; Gotelli, Nicholas J.; Escudero, Adrian; Ochoa, Victoria; Delgado-Baquerizo, Manuel; Garcia-Gomez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; Garcia-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceicao, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitan, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gomez-Gonzalez, Susana; Gutie, Julio R.; Hernandez, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Anibal; Pucheta, Eduardo; Ramirez-Collantes, David A.; Romao, Roberto; Tighe, Matthew; Torres-Diaz, Cristian; Val, James; Veiga, Jose P.; Wang, Deli; Zaady, Eli

    2012-01-01

    Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

  20. Engineering a plant community to deliver multiple ecosystem services.

    Science.gov (United States)

    Storkey, Jonathan; Döring, Thomas; Baddeley, John; Collins, Rosemary; Roderick, Stephen; Jones, Hannah; Watson, Christine

    2015-06-01

    The sustainable delivery of multiple ecosystem services requires the management of functionally diverse biological communities. In an agricultural context, an emphasis on food production has often led to a loss of biodiversity to the detriment of other ecosystem services such as the maintenance of soil health and pest regulation. In scenarios where multiple species can be grown together, it may be possible to better balance environmental and agronomic services through the targeted selection of companion species. We used the case study of legume-based cover crops to engineer a plant community that delivered the optimal balance of six ecosystem services: early productivity, regrowth following mowing, weed suppression, support of invertebrates, soil fertility building (measured as yield of following crop), and conservation of nutrients in the soil. An experimental species pool of 12 cultivated legume species was screened for a range of functional traits and ecosystem services at five sites across a geographical gradient in the United Kingdom. All possible species combinations were then analyzed, using a process-based model of plant competition, to identify the community that delivered the best balance of services at each site. In our system, low to intermediate levels of species richness (one to four species) that exploited functional contrasts in growth habit and phenology were identified as being optimal. The optimal solution was determined largely by the number of species and functional diversity represented by the starting species pool, emphasizing the importance of the initial selection of species for the screening experiments. The approach of using relationships between functional traits and ecosystem services to design multifunctional biological communities has the potential to inform the design of agricultural systems that better balance agronomic and environmental services and meet the current objective of European agricultural policy to maintain viable food

  1. Plant functional traits predict green roof ecosystem services.

    Science.gov (United States)

    Lundholm, Jeremy; Tran, Stephanie; Gebert, Luke

    2015-02-17

    Plants make important contributions to the services provided by engineered ecosystems such as green roofs. Ecologists use plant species traits as generic predictors of geographical distribution, interactions with other species, and ecosystem functioning, but this approach has been little used to optimize engineered ecosystems. Four plant species traits (height, individual leaf area, specific leaf area, and leaf dry matter content) were evaluated as predictors of ecosystem properties and services in a modular green roof system planted with 21 species. Six indicators of ecosystem services, incorporating thermal, hydrological, water quality, and carbon sequestration functions, were predicted by the four plant traits directly or indirectly via their effects on aggregate ecosystem properties, including canopy density and albedo. Species average height and specific leaf area were the most useful traits, predicting several services via effects on canopy density or growth rate. This study demonstrates that easily measured plant traits can be used to select species to optimize green roof performance across multiple key services.

  2. Health of plants, animals and ecosystems

    International Nuclear Information System (INIS)

    Marwitz, P.A.; Weers, A.W. van

    1988-12-01

    This report makes part of a series of eight reports which have been drawn up in behalf of the Dutch Policy Notition Radiation Standards (BNS). It presents the elaboration of subproject 2 'Health of plants, animals and ecosystems'. The study had been based upon the following questions: Does the application of the radiation-protection principes, intended to the protection of man, offer sufficient protection for populations of plants and animals?; If that sufficient protection does exsist, are there situations imagible which are exceptions therefore?; Which studies should be made if the forementioned questions cannot be answered sufficiently? The gravity of radiation effects turns out to depend on the radiation dose an on the part of the population which is exposed. On the base of literature it is concluded that effects upon aquatic and terristric populations are excluded below radiation levels of 1 mGy/day. From the application of the generic models it appears that the radiation burden of organisms will remain below 1 mGy/day. Since the radiation burden of man in actual practice will be nearly always lower certainly no effects upon plants, animals and ecosystems are to be expected. An exception is possible for situations in which the distribution does not take place in the living environment of man; in that case protection of man is no need for limiting the radiation levels. Such locations do not exsist in the Netherlands. For the Dutch situation, in view of the actual and expected radiation levels, the in the report derived upper limits for the radiation levels will certainly be reached. It is recommended to make for the Netherlands, starting from concrete source terms, estimations which are based upon concrete situations, with the help of the generic models. In view of the foregoing the necessity therefore is small. Next it is recommeded to keep following the international developments in this area. (H.W.). 60 refs.; 8 figs.; 3 tabs

  3. Primary production of tropical marine ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.

    Among tropical marine ecosystems estuaries are one of the highly productive areas and act as a nursery to large number of organisms. The primary production in most of the estuaries is less during the monsoon period. Post-monsoon period shows...

  4. Litter drives ecosystem and plant community changes in cattail invasion.

    Science.gov (United States)

    Farrer, Emily C; Goldberg, Deborah E

    2009-03-01

    Invaded systems are commonly associated with a change in ecosystem processes and a decline in native species diversity; however, many different causal pathways linking invasion, ecosystem change, and native species decline could produce this pattern. The initial driver of environmental change may be anthropogenic, or it may be the invader itself; and the mechanism behind native species decline may be the human-induced environmental change, competition from the invader, or invader-induced environmental change (non-trophic effects). We examined applicability of each of these alternate pathways in Great Lakes coastal marshes invaded by hybrid cattail (Typha x glauca). In a survey including transects in three marshes, we found that T. x glauca was associated with locally high soil nutrients, low light, and large amounts of litter, and that native diversity was highest in areas of shallow litter depth. We tested whether live T. x glauca plants or their litter induced changes in the environment and in diversity with a live plant and litter transplant experiment. After one year, Typha litter increased soil NH4+ and N mineralization twofold, lowered light levels, and decreased the abundance and diversity of native plants, while live Typha plants had no effect on the environment or on native plants. This suggests that T. x glauca, through its litter production, can cause the changes in ecosystem processes that we commonly attribute to anthropogenic nutrient loading and that T. x glauca does not displace native species through competition for resources, but rather affects them non-trophically through its litter. Moreover, because T. x glauca plants were taller when grown with their own litter, we suggest that this invader may produce positive feedbacks and change the environment in ways that benefit itself and may promote its own invasion.

  5. Plants in aquatic ecosystems: current trends and future directions

    NARCIS (Netherlands)

    O’Hare, Matthew T.; Aguiar, Francisca C.; Asaeda, Takashi; Bakker, Elisabeth S.; Chambers, Patricia A.; Clayton, John S.; Elger, Arnaud; Ferreira, Teresa M.; Gross, Elisabeth M.; Gunn, Iain D.M.; Gurnell, Angela M.; Hellsten, Seppo; Hofstra, Deborah E.; Li, Wei; Mohr, Silvia; Puijalon, Sara; Szoszkiewicz, Krzysztof; Willby, Nigel J.; Wood, Kevin A.

    2018-01-01

    Aquatic plants fulfil a wide range of ecological roles, and make a substantial contribution to the structure, function and service provision of aquatic ecosystems. Given their well-documented importance in aquatic ecosystems, research into aquatic plants continues to blossom. The 14th International

  6. Positive feedback between increasing atmospheric CO2 and ecosystem productivity

    Science.gov (United States)

    Gelfand, I.; Hamilton, S. K.; Robertson, G. P.

    2009-12-01

    Increasing atmospheric CO2 will likely affect both the hydrologic cycle and ecosystem productivity. Current assumptions that increasing CO2 will lead to increased ecosystem productivity and plant water use efficiency (WUE) are driving optimistic predictions of higher crop yields as well as greater availability of freshwater resources due to a decrease in evapotranspiration. The plant physiological response that drives these effects is believed to be an increase in carbon uptake either by (a) stronger CO2 gradient between the stomata and the atmosphere, or by (b) reduced CO2 limitation of enzymatic carboxylation within the leaf. The (a) scenario will lead to increased water use efficiency (WUE) in plants. However, evidence for increased WUE is mostly based on modeling studies, and experiments producing a short duration or step-wise increase in CO2 concentration (e.g. free-air CO2 enrichment). We hypothesize that the increase in atmospheric CO2 concentration is having a positive effect on ecosystem productivity and WUE. To investigate this hypothesis, we analyzed meteorological, ANPP, and soil CO2 flux datasets together with carbon isotopic ratio (13C/12C) of archived plant samples from the long term ecological research (LTER) program at Kellogg Biological Station. The datasets were collected between 1989 and 2007 (corresponding to an increase in atmospheric CO2 concentration of ~33 ppmv at Mauna Loa). Wheat (Triticum aestivum) samples taken from 1989 and 2007 show a significant decrease in the C isotope discrimination factor (Δ) over time. Stomatal conductance is directly related to Δ, and thus Δ is inversely related to plant intrinsic WUE (iWUE). Historical changes in the 13C/12C ratio (δ13C) in samples of a perennial forb, Canada goldenrod (Solidago canadensis), taken from adjacent successional fields, indicate changes in Δ upon uptake of CO2 as well. These temporal trends in Δ suggest a positive feedback between the increasing CO2 concentration in the

  7. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  8. Ecosystem simplification, biodiversity loss and plant virus emergence.

    Science.gov (United States)

    Roossinck, Marilyn J; García-Arenal, Fernando

    2015-02-01

    Plant viruses can emerge into crops from wild plant hosts, or conversely from domestic (crop) plants into wild hosts. Changes in ecosystems, including loss of biodiversity and increases in managed croplands, can impact the emergence of plant virus disease. Although data are limited, in general the loss of biodiversity is thought to contribute to disease emergence. More in-depth studies have been done for human viruses, but studies with plant viruses suggest similar patterns, and indicate that simplification of ecosystems through increased human management may increase the emergence of viral diseases in crops. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Dry alcohol production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for dry alcohol production plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects a production plant with a capacity of 40 m3/y was manufactured, at "Zorka Pharma", Šabac in 1995-1996. The product meets all quality demands, as well as environmental regulations. The dry alcohol production process is fully automatized. There is no waste in the process, neither gaseous, nor liquid. The chosen process provides safe operation according to temperature regime and resistance in the pipes, air purification columns and filters. Working at increased pressure is suitable for evaporation and condensation at increased temperatures. The production process can be controlled manually, which is necessary during start-up, and repairs.

  10. Whole-system nutrient enrichment increases secondary production in a detritus-based ecosystem

    Science.gov (United States)

    W.F. Cross; J.B. Wallace; A.D. Rosemond; S.L. Eggert

    2006-01-01

    Although the effects of nutrient enrichment on consumer-resource dynamics are relatively well studied in ecosystems based on living plants, little is known about the manner in which enrichment influences the dynamics and productivity of consumers and resources in detritus-based ecosystems. Because nutrients can stimulate loss of carbon at the base of detrital food webs...

  11. Wetland plant influence on sediment ecosystem structure and trophic function

    OpenAIRE

    Whitcraft, Christine René

    2007-01-01

    Vascular plants structure wetland ecosystems. To examine mechanisms behind their influence, plants were studied under different scenarios of change: experimental manipulation of cover, invasion, and response to flushing regimes. I tested the hypothesis that wetland plants alter benthic communities through modification of abiotic factors, with cascading effects on microalgae and invertebrate communities. Major plant effects were observed in all systems studied, but the magnitude of, mechanisms...

  12. Meaningful traits for grouping plant species across arid ecosystems.

    Science.gov (United States)

    Bär Lamas, Marlene Ivonne; Carrera, A L; Bertiller, M B

    2016-05-01

    Grouping species may provide some degree of simplification to understand the ecological function of plants on key ecosystem processes. We asked whether groups of plant species based on morpho-chemical traits associated with plant persistence and stress/disturbance resistance reflect dominant plant growth forms in arid ecosystems. We selected twelve sites across an aridity gradient in northern Patagonia. At each site, we identified modal size plants of each dominant species and assessed specific leaf area (SLA), plant height, seed mass, N and soluble phenol concentration in green and senesced leaves at each plant. Plant species were grouped according with plant growth forms (perennial grasses, evergreen shrubs and deciduous shrubs) and plant morphological and/or chemical traits using cluster analysis. We calculated mean values of each plant trait for each species group and plant growth form. Plant growth forms significantly differed among them in most of the morpho-chemical traits. Evergreen shrubs were tall plants with the highest seed mass and soluble phenols in leaves, deciduous shrubs were also tall plants with high SLA and the highest N in leaves, and perennial grasses were short plants with high SLA and low concentration of N and soluble phenols in leaves. Grouping species by the combination of morpho-chemical traits yielded 4 groups in which species from one growth form prevailed. These species groups differed in soluble phenol concentration in senesced leaves and plant height. These traits were highly correlated. We concluded that (1) plant height is a relevant synthetic variable, (2) growth forms adequately summarize ecological strategies of species in arid ecosystems, and (3) the inclusion of plant morphological and chemical traits related to defenses against environmental stresses and herbivory enhanced the potential of species grouping, particularly within shrubby growth forms.

  13. Plant community mediation of ecosystem responses to global change factors

    Science.gov (United States)

    Churchill, A. C.

    2017-12-01

    Human alteration of the numerous environmental drivers affecting ecosystem processes is unprecedented in the last century, including changes in climate regimes and rapid increases in the availability of biologically active nitrogen (N). Plant communities may offer stabilizing or amplifying feedbacks mediating potential ecosystem responses to these alterations, and my research seeks to examine the conditions associated with when plant feedbacks are important for ecosystem change. My dissertation research focused on the unintended consequences of N deposition into natural landscapes, including alpine ecosystems which are particularly susceptible to adverse environmental impacts. In particular, I examined alpine plant and soil responses to N deposition 1) across multiple spatial scales throughout the Southern Rocky Mountains, 2) among diverse plant communities associated with unique environmental conditions common in the alpine of this region, and 3) among ecosystem pools of N contributing to stabilization of N inputs within those communities. I found that communities responded to inputs of N differently, often associated with traits of dominant plant species but these responses were intimately linked with the abiotic conditions of each independent community. Even so, statistical models predicting metrics of N processing in the alpine were improved by encompassing both abiotic and biotic components of the main community types.

  14. Noise-induced stability in dryland plant ecosystems.

    Science.gov (United States)

    D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2005-08-02

    Dryland plant ecosystems tend to exhibit bistable dynamics with two preferential configurations of bare and vegetated soils. Climate fluctuations are usually believed to act as a source of disturbance on these ecosystems and to reduce their stability and resilience. In contrast, this work shows that random interannual fluctuations of precipitation may lead to the emergence of an intermediate statistically stable condition between the two stable states of the deterministic dynamics of vegetation. As a result, there is an enhancement of ecosystem resilience and a decrease in the likelihood of catastrophic shifts to the desert state.

  15. A review of impacts by invasive exotic plants on forest ecosystem services

    Science.gov (United States)

    Kevin Devine; Songlin. Fei

    2011-01-01

    Many of our forest ecosystems are at risk due to the invasion of exotic invasive plant species. Invasive plant species pose numerous threats to ecosystems by decreasing biodiversity, deteriorating ecosystem processes, and degrading ecosystem services. Literature on Kentucky's most invasive exotic plant species was examined to understand their potential impacts on...

  16. Biomass production efficiency controlled by management in temperate and boreal ecosystems

    Science.gov (United States)

    Campioli, M.; Vicca, S.; Luyssaert, S.; Bilcke, J.; Ceschia, E.; Chapin, F. S., III; Ciais, P.; Fernández-Martínez, M.; Malhi, Y.; Obersteiner, M.; Olefeldt, D.; Papale, D.; Piao, S. L.; Peñuelas, J.; Sullivan, P. F.; Wang, X.; Zenone, T.; Janssens, I. A.

    2015-11-01

    Plants acquire carbon through photosynthesis to sustain biomass production, autotrophic respiration and production of non-structural compounds for multiple purposes. The fraction of photosynthetic production used for biomass production, the biomass production efficiency, is a key determinant of the conversion of solar energy to biomass. In forest ecosystems, biomass production efficiency was suggested to be related to site fertility. Here we present a database of biomass production efficiency from 131 sites compiled from individual studies using harvest, biometric, eddy covariance, or process-based model estimates of production. The database is global, but dominated by data from Europe and North America. We show that instead of site fertility, ecosystem management is the key factor that controls biomass production efficiency in terrestrial ecosystems. In addition, in natural forests, grasslands, tundra, boreal peatlands and marshes, biomass production efficiency is independent of vegetation, environmental and climatic drivers. This similarity of biomass production efficiency across natural ecosystem types suggests that the ratio of biomass production to gross primary productivity is constant across natural ecosystems. We suggest that plant adaptation results in similar growth efficiency in high- and low-fertility natural systems, but that nutrient influxes under managed conditions favour a shift to carbon investment from the belowground flux of non-structural compounds to aboveground biomass.

  17. Valuing ecosystem services. A shadow price for net primary production

    International Nuclear Information System (INIS)

    Richmond, Amy; Kaufmann, Robert K.; Myneni, Ranga B.

    2007-01-01

    We analyze the contribution of ecosystem services to GDP and use this contribution to calculate an empirical price for ecosystem services. Net primary production is used as a proxy for ecosystem services and, along with capital and labor, is used to estimate a Cobb Douglas production function from an international panel. A positive output elasticity for net primary production probably measures both marketed and nonmarketed contributions of ecosystems services. The production function is used to calculate the marginal product of net primary production, which is the shadow price for ecosystem services. The shadow price generally is greatest for developed nations, which have larger technical scalars and use less net primary production per unit output. The rate of technical substitution indicates that the quantity of capital needed to replace a unit of net primary production tends to increase with economic development, and this rate of replacement may ultimately constrain economic growth. (author)

  18. Plant hydraulic diversity buffers forest ecosystem responses to drought

    Science.gov (United States)

    Anderegg, W.; Konings, A. G.; Trugman, A. T.; Pacala, S. W.; Yu, K.; Sulman, B. N.; Sperry, J.; Bowling, D. R.

    2017-12-01

    Drought impacts carbon, water, and energy cycles in forests and may pose a fundamental threat to forests in future climates. Plant hydraulic transport of water is central to tree drought responses, including curtailing of water loss and the risk of mortality during drought. The effect of biodiversity on ecosystem function has typically been examined in grasslands, yet the diversity of plant hydraulic strategies may influence forests' response to drought. In a combined analysis of eddy covariance measurements, remote-sensing data of plant water content variation, model simulations, and plant hydraulic trait data, we test the degree to which plant water stress schemes influence the carbon cycle and how hydraulic diversity within and across ecosystems affects large-scale drought responses. We find that current plant functional types are not well-suited to capture hydraulic variation and that higher hydraulic diversity buffers ecosystem variation during drought. Our results demonstrate that tree functional diversity, particularly hydraulic diversity, may be critical to simulate in plant functional types in current land surface model projections of future vegetation's response to climate extremes.

  19. Chemical sensing of plant stress at the ecosystem scale

    Directory of Open Access Journals (Sweden)

    T. Karl

    2008-09-01

    Full Text Available Significant ecosystem-scale emissions of methylsalicylate (MeSA, a semivolatile plant hormone thought to act as the mobile signal for systemic acquired resistance (SAR, were observed in an agroforest. Our measurements show that plant internal defence mechanisms can be activated in response to temperature stress and are modulated by water availability on large scales. Highest MeSA fluxes (up to 0.25 mg/m2/h were observed after plants experienced ambient night-time temperatures of ~7.5°C followed by a large daytime temperature increase (e.g. up to 22°C. Under these conditions estimated night-time leaf temperatures were as low as ~4.6°C, likely inducing a response to prevent chilling injury. Our observations imply that plant hormones can be a significant component of ecosystem scale volatile organic compound (VOC fluxes (e.g. as high as the total monoterpene (MT flux and therefore contribute to the missing VOC budget. If generalized to other ecosystems and different types of stresses these findings suggest that semivolatile plant hormones have been overlooked by investigations of the impact of biogenic VOCs on aerosol formation events in forested regions. Our observations show that the presence of MeSA in canopy air serves as an early chemical warning signal indicating ecosystem-scale stresses before visible damage becomes apparent. As a chemical metric, ecosystem emission measurements of MeSA in ambient air could therefore support field studies investigating factors that adversely affect plant growth.

  20. The Coupling of Ecosystem Productivity and Water Availability in Dryland Regions

    Science.gov (United States)

    Scott, R. L.; Biederman, J. A.; Barron-Gafford, G.

    2014-12-01

    Land cover and climatic change will alter biosphere-atmosphere exchanges of water vapor and carbon dioxide depending, in part, on feedbacks between biotic activity and water availability. Eddy covariance observations allow us to estimate ecosystem-scale productivity and respiration, and these datasets are now becoming sufficiently mature to advance understanding of these ecohydrological interactions. Here we use a network of sites in semiarid western North America representing gradients of water availability and functional plant type. We examine how precipitation (P) controls evapotranspiration (ET), net ecosystem production (NEP), and its component fluxes of ecosystem respiration (Reco) and gross ecosystem production (GEP). Despite the high variability in seasonal and annual precipitation timing and amounts that we expect to influence ecosystem function, we find persistent overall relationships between P or ET and the fluxes of NEP, Reco and GEP across the network, indicating a commonality and resilience in ecosystem soil and plant response to water availability. But we also observe several important site differences such as prior seasonal legacy effects on subsequent fluxes which vary depending on dominant plant functional type. For example, multiyear droughts, episodic cool-season droughts, and hard winter freezes seem to affect the herbaceous species differently than the woody ones. Nevertheless, the overall, strong coupling between hydrologic and ecologic processes at these sites bolsters our ability to predict the response of dryland ecosystems to future precipitation change.

  1. Effects of plant diversity on primary production and species interactions in brackish water angiosperm communities

    DEFF Research Database (Denmark)

    Salo, Tiina; Gustafsson, Camilla; Boström, Christoffer

    2009-01-01

    Research on plant biodiversity and ecosystem functioning has mainly focused on terrestrial ecosystems, and our understanding of how plant species diversity and interactions affect processes in marine ecosystems is still limited. To investigate if plant species richness and composition influence...... plant productivity in brackish water angiosperm communities, a 14 wk field experiment was conducted. Using a replacement design with a standardized initial aboveground biomass, shoots of Zostera marina, Potamogeton filiformis and P. perfoliatus were planted on a shallow, sandy bottom in replicated...

  2. The Green Roof Microbiome: Improving Plant Survival for Ecosystem Service Delivery

    Directory of Open Access Journals (Sweden)

    Roberta Fulthorpe

    2018-02-01

    Full Text Available Plants are key contributors to ecosystem services delivered by green roofs in cities including stormwater capture, temperature regulation, and wildlife habitat. As a result, current research has primarily focused on their growth in relationship to extensive green roof (e.g., substrates <15 cm depth ecosystem services. Green roofs are exposed to a variety of harsh abiotic factors such as intense solar radiation, wind, and isolation from ground-level habitats, making survival exceedingly difficult. Plants in natural habitats benefit from a variety of interactions with fungi and bacteria. These plant-microbial interactions improve mechanisms of survival and productivity; however, many green roof substrates are sterilized prior to installation and lack microbial communities with unstudied consequences for green roof plant health and subsequent survival and performance. In this paper, we present six hypotheses on the positive role of microbes in green roof applications. In natural and experimental systems, microbial interactions have been linked to plant (1 drought tolerance, (2 pathogen protection, (3 nutrient availability, (4 salt tolerance, (5 phytohormone production, and (6 substrate stabilization, all of which are desirable properties of green roof ecosystems. As few studies exist that directly examine these relationships on green roofs, we explore the existing ecological literature on these topics to unravel the mechanisms that could support more complex green roof ecosystem and lead to new insight into the design, performance, and broader applications in green infrastructure.

  3. Forest ecosystem services: Provisioning of non-timber forest products

    Science.gov (United States)

    James L. Chamberlain; Gregory E. Frey; C. Denise Ingram; Michael G. Jacobson; Cara Meghan Starbuck Downes

    2017-01-01

    The purpose of this chapter is to describe approaches to calculate a conservative and defensible estimate of the marginal value of forests for non-timber forest products (NTFPs). 'Provisioning" is one of four categories of benefits, or services that ecosystems provide to humans and was described by the Millennium Ecosystem Assessment as 'products...

  4. Microbial Community Activity And Plant Biomass Are Insensitive To Passive Warming In A Semiarid Ecosystem

    Science.gov (United States)

    Espinosa, N. J.; Fehmi, J. S.; Rasmussen, C.; Gallery, R. E.

    2017-12-01

    Soil microorganisms drive biogeochemical and nutrient cycling through the production of extracellular enzymes that facilitate organic matter decomposition and the flux of large amounts of carbon dioxide to the atmosphere. Although dryland ecosystems occupy over 40% of land cover and are projected to expand due to climate change, much of our current understanding of these processes comes from mesic temperate ecosystems. Understanding the responses of these globally predominant dryland ecosystems is therefore important yet complicated by co-occurring environmental changes. For example, the widespread and pervasive transition from grass to woody dominated landscapes is changing the hydrology, fire regimes, and carbon storage potential of semiarid ecosystems. In this study, we used a novel passive method of warming to conduct a warming experiment with added plant debris as either woodchip or biochar, to simulate different long-term carbon additions that accompany woody plant encroachment in semiarid ecosystems. The response of heterotrophic respiration, plant biomass, and microbial activity was monitored bi-annually. We hypothesized that the temperature manipulations would have direct and indirect effects on microbial activity. Warmer soils directly reduce the activity of soil extracellular enzymes through denaturation and dehydration of soil pores and indirectly through reducing microbe-available substrates and plant inputs. Overall, reduction in extracellular enzyme activity may reduce decomposition of coarse woody debris and potentially enhance soil carbon storage in semiarid ecosystems. For all seven hydrolytic enzymes examined as well as heterotrophic respiration, there was no consistent or significant response to experimental warming, regardless of seasonal climatic and soil moisture variation. The enzyme results observed here are consistent with the few other experimental results for warming in semiarid ecosystems and indicate that the controls over soil

  5. Soil-plant transfer factors in forest ecosystems

    International Nuclear Information System (INIS)

    Strebl, F.; Gerzabek, M.H.

    1995-04-01

    Within scope of an extended study about 137 Cs behaviour in forest ecosystems several parameters were found to influence soil-plant transfer factors. TF-values of different plant species cover a range of two magnitudes. This is partly due to variations in rooting depth of plants and specific physiological adaptations of nutrient supply. Perrenial plants like trees (Picea abies) and dwarf shrubs (Vaccinium myrtillus) showed a distinct age - dependency of 137 Cs - transfer factors. In young plant parts caesium concentration is higher than in old, more signified twigs. A correlation analysis of physico-chemical soil parameters and TF-values to forest vegetation showed, that soil organic matter, especially the degree of humification and the ratio between extractable fulvic to humic acids are important influencing factors of 137 Cs transfer from forest soils to plants. (author)

  6. Marine ecosystem analysis for Kori nuclear power plant

    International Nuclear Information System (INIS)

    Lee, C.H.; Kim, Y.H.; Cho, T.S.

    1980-01-01

    The effect of both radioactive and thermal effluents discharged from the plant on aquatic ecosystem is one of the primary concerns in evaluating the environmental impact due to the operation of the nuclear power plant. Biological alteration of aquatic ecosystems may be resulted from radioactive effluents, thermal pollution and chemical releases. There is also another possible synergistic effect, that is, the combination of the above stresses, which may cause an impact severer than that of the sum of the individual impact. This report deals with species diversity and seasonal variations of those numbers of phytoplankton, marine algae and microorganisms, and distribution of radioactivity of marine organisms, as well as those data pertaining to sea water analysis. The present survey is designed to provide a partial baseline information for environmental impact assessment of Kori nuclear plant unit no. 1. (author)

  7. Marine-ecosystem analysis for the Kori nuclear power plant

    International Nuclear Information System (INIS)

    Lee, J.H.; Kim, Y.H.

    1979-01-01

    The effects of radioactive effluents and warm water discharged from the plant on aquatic ecosystem is one of the primary considerations in evaluating the impact due to the operation of the nuclear power plant. Biological alteration of aquatic ecosystems may be resulted from radioactive effluents, thermal pollution and chemical releases; there is also the possible synergistic effect, that is, the combination of the above stresses, which may cause an effect greater than that of the sum of the individual effects. This report deals with species diversity and seasonal vegetation of phytoplankton, marine algae and microorganisms, radioactive contamination of marine organisms, and lateral distribution of sea water temperature from discharge point. The present investigation is designed to provide a partial baseline information for environmental safety against Kori nuclear power plant. (author)

  8. Biochar and Ecosystem Restoration: Plant Ecophysiological Responses

    Science.gov (United States)

    Gale, N.; Halim, M. A.; Thomas, S. C.

    2017-12-01

    Charcoal is thought to facilitate rapid plant regeneration following fires by increasing the retention and availability of nutrients and water, increasing soil pH, and by sorbing toxic and inhibitory soil compounds - responses that have recently encouraged research on "biochar," or charcoal used as a soil amendment. Interest in biochar for use in the restoration of disturbed systems is growing; however, investigations of the effects of biochar on wild plants and trees are lacking. We present results from two experiments testing the influence of biochar on the growth and physiology of pioneers. In the first study, in a glasshouse, we examined the effects of maple biochar (10 and 20 t/ha) applied to a temperate managed forest soil on the ecophysiology of 13 herbaceous old-field species. In the second study, in field trials in Bangladesh (15 x 15 m plots), we examined the effects of acacia biochar (7.5 t/ha) on the growth of regenerating dipterocarp secondary forests. In both experiments, we measured changes in nutrient availability to help explain ecophysiological responses. Biochars enhanced the performance of early successional old-field pioneers: increasing aboveground biomass (37%), photosynthesis (17%), reproductive biomass (100%), and water use efficiency (44%), but with high species-specific variation that included negative responses. In tropical forests, biochars marginally improved the growth and recruitment of canopy dipterocarps and increased the photosynthetic performance and abundance of some, but not all, of the dominant understory species. In both experiments, growth enhancement was due to pulses of PO4-and K+ supplied by biochar in the short term; while null and negative responses were the result of nitrogen immobilization for species with high photosynthetic capacities. These results suggest that by providing a pulse of P and base cations, biochar can improve the restoration of disturbed landscapes by enhancing the physiological performance of

  9. Linking Ecosystem Services Benefit Transfer Databases and Ecosystem Services Production Function Libraries

    Science.gov (United States)

    The quantification or estimation of the economic and non-economic values of ecosystem services can be done from a number of distinct approaches. For example, practitioners may use ecosystem services production function models (ESPFMs) for a particular location, or alternatively, ...

  10. Explaining plant-soil diversity in Alpine ecosystems: more than just time since ecosystem succession started

    Science.gov (United States)

    Lane, Stuart; Baetz, Nico; Borgeaud, Laure; Verrecchia, Eric; Vittoz, Pascal

    2014-05-01

    Ecosystem succession in Alpine environments has been a focus of research for many decades. Following from the classic ideas of Jenny (1941, 1961), following perturbation, an ecosystem (flora, fauna and soil) should evolve as a function of time at a rate conditioned by external variables (relief, climate, geology). More recently, biogeomorphologists have focused upon the notion of co-evolution of geomorphic processes with ecosystems over very short through to very long (evolutionary) time-scales. Alpine environments have been a particular focus of models of co-evolution, as a means of understanding the rate of plant colonization of previously glaciated terrain. However, work in this field has tended to adopt an over simplified view of the relationship between perturbation and succession, including: how the landform and ecosystem itself conditions the impact of a perturbation to create a complex spatial impact; and how perturbations are not simply ecosystem destroyers but can be a significant source of ecosystem resources. What this means is that at the within landform scale, there may well be a complex and dynamic topographic and sedimentological template that co-evolves with the development of soil, flora and fauna. In this paper, we present and test conceptual models for such co-evolution for an Alpine alluvial fan and an Alpine piedmont braided river. We combine detailed floristic inventory with soil inventory, survey of edaphic variables above and below ground (e.g. vertical and lateral sedimentological structure, using electrical resistance tomography) and the analysis of historical aerial imagery. The floristic inventory shows the existence of a suite of distinct plant communities within each landform. Time since last perturbation is not a useful explanatory variable of the spatial distribution of these communities because: (1) perturbation impacts are spatially variable, as conditioned by the extent distribution of topographic, edaphic and ecological

  11. Calcium constrains plant control over forest ecosystem nitrogen cycling.

    Science.gov (United States)

    Groffman, Peter M; Fisk, Melany C

    2011-11-01

    Forest ecosystem nitrogen (N) cycling is a critical controller of the ability of forests to prevent the movement of reactive N to receiving waters and the atmosphere and to sequester elevated levels of atmospheric carbon dioxide (CO2). Here we show that calcium (Ca) constrains the ability of northern hardwood forest trees to control the availability and loss of nitrogen. We evaluated soil N-cycling response to Ca additions in the presence and absence of plants and observed that when plants were present, Ca additions "tightened" the ecosystem N cycle, with decreases in inorganic N levels, potential net N mineralization rates, microbial biomass N content, and denitrification potential. In the absence of plants, Ca additions induced marked increases in nitrification (the key process controlling ecosystem N losses) and inorganic N levels. The observed "tightening" of the N cycle when Ca was added in the presence of plants suggests that the capacity of forests to absorb elevated levels of atmospheric N and CO2 is fundamentally constrained by base cations, which have been depleted in many areas of the globe by acid rain and forest harvesting.

  12. Ecosystem-scale plant hydraulic strategies inferred from remotely-sensed soil moisture

    Science.gov (United States)

    Bassiouni, M.; Good, S. P.; Higgins, C. W.

    2017-12-01

    Characterizing plant hydraulic strategies at the ecosystem scale is important to improve estimates of evapotranspiration and to understand ecosystem productivity and resilience. However, quantifying plant hydraulic traits beyond the species level is a challenge. The probability density function of soil moisture observations provides key information about the soil moisture states at which evapotranspiration is reduced by water stress. Here, an inverse Bayesian approach is applied to a standard bucket model of soil column hydrology forced with stochastic precipitation inputs. Through this approach, we are able to determine the soil moisture thresholds at which stomata are open or closed that are most consistent with observed soil moisture probability density functions. This research utilizes remotely-sensed soil moisture data to explore global patterns of ecosystem-scale plant hydraulic strategies. Results are complementary to literature values of measured hydraulic traits of various species in different climates and previous estimates of ecosystem-scale plant isohydricity. The presented approach provides a novel relation between plant physiological behavior and soil-water dynamics.

  13. Ecosystem Fabrication (EcoFAB) Protocols for The Construction of Laboratory Ecosystems Designed to Study Plant-microbe Interactions.

    Science.gov (United States)

    Gao, Jian; Sasse, Joelle; Lewald, Kyle M; Zhalnina, Kateryna; Cornmesser, Lloyd T; Duncombe, Todd A; Yoshikuni, Yasuo; Vogel, John P; Firestone, Mary K; Northen, Trent R

    2018-04-10

    Beneficial plant-microbe interactions offer a sustainable biological solution with the potential to boost low-input food and bioenergy production. A better mechanistic understanding of these complex plant-microbe interactions will be crucial to improving plant production as well as performing basic ecological studies investigating plant-soil-microbe interactions. Here, a detailed description for ecosystem fabrication is presented, using widely available 3D printing technologies, to create controlled laboratory habitats (EcoFABs) for mechanistic studies of plant-microbe interactions within specific environmental conditions. Two sizes of EcoFABs are described that are suited for the investigation of microbial interactions with various plant species, including Arabidopsis thaliana, Brachypodium distachyon, and Panicum virgatum. These flow-through devices allow for controlled manipulation and sampling of root microbiomes, root chemistry as well as imaging of root morphology and microbial localization. This protocol includes the details for maintaining sterile conditions inside EcoFABs and mounting independent LED light systems onto EcoFABs. Detailed methods for addition of different forms of media, including soils, sand, and liquid growth media coupled to the characterization of these systems using imaging and metabolomics are described. Together, these systems enable dynamic and detailed investigation of plant and plant-microbial consortia including the manipulation of microbiome composition (including mutants), the monitoring of plant growth, root morphology, exudate composition, and microbial localization under controlled environmental conditions. We anticipate that these detailed protocols will serve as an important starting point for other researchers, ideally helping create standardized experimental systems for investigating plant-microbe interactions.

  14. Water management and productivity in planted forests

    Directory of Open Access Journals (Sweden)

    J. E. Nettles

    2014-09-01

    Full Text Available As climate variability endangers water security in many parts of the world, maximizing the carbon balance of plantation forestry is of global importance. High plant water use efficiency is generally associated with lower plant productivity, so an explicit balance in resources is necessary to optimize water yield and tree growth. This balance requires predicting plant water use under different soil, climate, and planting conditions, as well as a mechanism to account for trade-offs in ecosystem services. Several strategies for reducing the water use of forests have been published but there is little research tying these to operational forestry. Using data from silvicultural and biofuel feedstock research in pine plantation ownership in the southeastern USA, proposed water management tools were evaluated against known treatment responses to estimate water yield, forest productivity, and economic outcomes. Ecosystem impacts were considered qualitatively and related to water use metrics. This work is an attempt to measure and compare important variables to make sound decisions about plantations and water use.

  15. Water and Nitrogen Limitations of Ecosystem Processes Across Three Dryland Plant Communities

    Science.gov (United States)

    Beltz, C.; Lauenroth, W. K.; Burke, I. C.

    2017-12-01

    The availability of water and nitrogen (N) play a major role in controlling the distribution of ecosystem types and the rates of ecosystem processes across the globe. Both these resources are being altered by human activity. Anthropogenic fixation of N has increased inputs into the biosphere from 0.5 kg N ha-1 yr-1 to upwards of 10 kg N ha-1 yr-1, while the amount and seasonality of precipitation are expected to continue to change. Within dryland environments, the relationships between increasingly available N and ecosystem processes are especially complex due to dryland's characteristic strong limitation by low and highly variable precipitation. Other experiments have shown that this interplay between N and water can cause temporally complex co-limitation and spatially complex responses with variable effects on ecosystems, such as those to net primary productivity, soil respiration, and plant community composition. Research spanning multiple dryland plant communities is critical for generalizing findings to the 40% of the Earth's terrestrial surface covered in dryland ecosystems. Given IPCC projections in which both N availability and precipitation are altered, examining their interactive effect across multiple plant communities is critical to increasing our understanding of the limitations to ecosystem process in drylands. We are studying a gradient of three plant communities representing a C4 grassland (shortgrass steppe), a C3/C4 grassland (mixed grass prairie), and a shrub-dominated ecosystem with C3 and C4 grasses (sagebrush steppe). We added two levels of N (10 kg N ha-1 and 100 kg N ha-1) and increased summer monthly precipitation by 20%. Sites responded differently to treatments, with the scale of effect varying by treatment. The high-level nitrogen increased soil N availability and soil respiration, while decreasing soil carbon in the labile pool in the upper soil layers. These results will allow for better understanding of increased N in combination with

  16. The roles of productivity and ecosystem size in determining food chain length in tropical terrestrial ecosystems.

    Science.gov (United States)

    Young, Hillary S; McCauley, Douglas J; Dunbar, Robert B; Hutson, Michael S; Ter-Kuile, Ana Miller; Dirzo, Rodolfo

    2013-03-01

    Many different drivers, including productivity, ecosystem size, and disturbance, have been considered to explain natural variation in the length of food chains. Much remains unknown about the role of these various drivers in determining food chain length, and particularly about the mechanisms by which they may operate in terrestrial ecosystems, which have quite different ecological constraints than aquatic environments, where most food chain length studies have been thus far conducted. In this study, we tested the relative importance of ecosystem size and productivity in influencing food chain length in a terrestrial setting. We determined that (1) there is no effect of ecosystem size or productive space on food chain length; (2) rather, food chain length increases strongly and linearly with productivity; and (3) the observed changes in food chain length are likely achieved through a combination of changes in predator size, predator behavior, and consumer diversity along gradients in productivity. These results lend new insight into the mechanisms by which productivity can drive changes in food chain length, point to potential for systematic differences in the drivers of food web structure between terrestrial and aquatic systems, and challenge us to consider how ecological context may control the drivers that shape food chain length.

  17. Local loss and spatial homogenization of plant diversity reduce ecosystem multifunctionality

    Science.gov (United States)

    Experimental studies show that local plant species loss decreases ecosystem functioning and services, but it remains unclear how other changes in biodiversity, such as spatial homogenization, alter multiple processes (multifunctionality) in natural ecosystems. We present a global analysis of eight ...

  18. Habitat connectivity and ecosystem productivity: implications from a simple model.

    Science.gov (United States)

    Cloern, James E

    2007-01-01

    The import of resources (food, nutrients) sustains biological production and food webs in resource-limited habitats. Resource export from donor habitats subsidizes production in recipient habitats, but the ecosystem-scale consequences of resource translocation are generally unknown. Here, I use a nutrient-phytoplankton-zooplankton model to show how dispersive connectivity between a shallow autotrophic habitat and a deep heterotrophic pelagic habitat can amplify overall system production in metazoan food webs. This result derives from the finite capacity of suspension feeders to capture and assimilate food particles: excess primary production in closed autotrophic habitats cannot be assimilated by consumers; however, if excess phytoplankton production is exported to food-limited heterotrophic habitats, it can be assimilated by zooplankton to support additional secondary production. Transport of regenerated nutrients from heterotrophic to autotrophic habitats sustains higher system primary production. These simulation results imply that the ecosystem-scale efficiency of nutrient transformation into metazoan biomass can be constrained by the rate of resource exchange across habitats and that it is optimized when the transport rate matches the growth rate of primary producers. Slower transport (i.e., reduced connectivity) leads to nutrient limitation of primary production in autotrophic habitats and food limitation of secondary production in heterotrophic habitats. Habitat fragmentation can therefore impose energetic constraints on the carrying capacity of aquatic ecosystems. The outcomes of ecosystem restoration through habitat creation will be determined by both functions provided by newly created aquatic habitats and the rates of hydraulic connectivity between them.

  19. Climate change drives a shift in peatland ecosystem plant community: implications for ecosystem function and stability.

    Science.gov (United States)

    Dieleman, Catherine M; Branfireun, Brian A; McLaughlin, James W; Lindo, Zoë

    2015-01-01

    The composition of a peatland plant community has considerable effect on a range of ecosystem functions. Peatland plant community structure is predicted to change under future climate change, making the quantification of the direction and magnitude of this change a research priority. We subjected intact, replicated vegetated poor fen peat monoliths to elevated temperatures, increased atmospheric carbon dioxide (CO2 ), and two water table levels in a factorial design to determine the individual and synergistic effects of climate change factors on the poor fen plant community composition. We identify three indicators of a regime shift occurring in our experimental poor fen system under climate change: nonlinear decline of Sphagnum at temperatures 8 °C above ambient conditions, concomitant increases in Carex spp. at temperatures 4 °C above ambient conditions suggesting a weakening of Sphagnum feedbacks on peat accumulation, and increased variance of the plant community composition and pore water pH through time. A temperature increase of +4 °C appeared to be a threshold for increased vascular plant abundance; however the magnitude of change was species dependent. Elevated temperature combined with elevated CO2 had a synergistic effect on large graminoid species abundance, with a 15 times increase as compared to control conditions. Community analyses suggested that the balance between dominant plant species was tipped from Sphagnum to a graminoid-dominated system by the combination of climate change factors. Our findings indicate that changes in peatland plant community composition are likely under future climate change conditions, with a demonstrated shift toward a dominance of graminoid species in poor fens. © 2014 John Wiley & Sons Ltd.

  20. Managing flood prone ecosystem for rice production in Bihar plains

    International Nuclear Information System (INIS)

    Khan, A.R.; Singh, S.S.

    2002-06-01

    A large area of the eastern region especially Bihar (0.5 million hectare) faces flood submergence and/or drought every year which creates an unfavorable environment for crop production. In this ecosystem only flood prone rice is grown whose cultivation is entirely different than normal rice crop. Managing the flood prone ecosystem for rice production needs to evaluate the reasons and a comprehensive appropriate technology through research efforts for better rice production under such harsh ecology. An attempt was made to develop a suitable agronomic package for rice cultivation during and after flooding in flood prone plains of Bihar. (author)

  1. Marine ecosystem analysis for wolsung nuclear power plant

    International Nuclear Information System (INIS)

    Lee, J.H.; Kim, Y.H.; Cho, T.J.

    1982-01-01

    Environmental surveys to provide base-line data for assessing the potential impact of the operation of Wolseong NPP on marine ecosystems were performed at 3-month intervals in 1981. Physico-chemical properties of seawater and gross beta activities in seawater and marine organisms were examined. The result shows that the ecosystems are non-polluted, typical of near-shore waters. The results of ecological surveys are summarized as follows: A total of 84 taxa of phytoplankton diatom were identified. Of the species, about 70 % are described as neritic species, and the major bloom occurred in September. The analysis of diversity indices shows that the community is very stable. The dominant species of zooplankton were protozoan Noctiluca scintillans and copepods. A total of 83 species of marine algae were identified. The algal community was more diverse in September-December than in March-July, and the dominant species were Chondria crassicaulis and Corallina pilulifera. Total algal production per unit area (0.25 m 2 ) was, on the average, 20 g-dry. The biomass of bacterial population was highest in December, and the result of multiple regression analysis indicates that the important environmental factors are nutrients, salinity and temperature. Primary productivities measured by Carbon-14 method were 1.11 mg C/m 3 /hr at 1 m depth, and 1.45 mg C/m 3 /hr at 6 m depth. As a whole the marine ecosystems adjacent Wolseong NPP site are thought to be stable. (author)

  2. The arable plant ecosystem as battleground for emergence of human pathogens

    Directory of Open Access Journals (Sweden)

    Leo eVan Overbeek

    2014-03-01

    Full Text Available Disease incidences related to Escherichia coli and Salmonella enterica infections by consumption of (fresh vegetables, sprouts and occasionally fruits made clear that these pathogens are not only transmitted to humans via the ‘classical’ routes of meat, eggs and dairy products, but also can be transmitted to humans via plants or products derived from plants. Nowadays, it is of major concern that these human pathogens, especially the ones belonging to the taxonomical family of Enterobacteriaceae, become adapted to environmental habitats without losing their virulence to humans. Adaptation to the plant environment would lead to longer persistence in plants, increasing their chances on transmission to humans via consumption of plant-derived food. One of the mechanisms of adaptation to the plant environment in human pathogens, proposed in this paper, is horizontal transfer of genes from different microbial communities present in the arable ecosystem, like the ones originating from soil, animal digestive track systems (manure, water and plants themselves. Genes that would confer better adaptation to the phytosphere might be genes involved in plant colonization, stress resistance and nutrient acquisition and utilization. Because human pathogenic enterics often were prone to genetic exchanges via phages and conjugative plasmids, it was postulated that these genetic elements may be hold key responsible for horizontal gene transfers between human pathogens and indigenous microbes in agroproduction systems. In analogy to zoonosis, we coin the term phytonosis for a human pathogen that is transmitted via plants and not exclusively via animals.

  3. Will Global Change Effect Primary Productivity in Coastal Ecosystems?

    Science.gov (United States)

    Rothschild, Lynn J.; Peterson, David L. (Technical Monitor)

    1997-01-01

    Algae are the base of coastal food webs because they provide the source of organic carbon for the remaining members of the community. Thus, the rate that they produce organic carbon to a large extent controls the productivity of the entire ecosystem. Factors that control algal productivity range from the physical (e.g., temperature, light), chemical (e.g., nutrient levels) to the biological (e.g., grazing). Currently, levels of atmospheric carbon dioxide surficial fluxes of ultraviolet radiation are rising. Both of these environmental variables can have a profound effect on algal productivity. Atmospheric carbon dioxide may increase surficial levels of dissolved inorganic carbon. Our laboratory and field studies of algal mats and phytoplankton cultures under ambient and elevated levels of pCO2 show that elevated levels of inorganic carbon can cause an increase in photosynthetic rates. In some cases, this increase will cause an increase in phytoplankton numbers. There may be an increase in the excretion of fixed carbon, which in turn may enhance bacterial productivity. Alternatively, in analogy with studies on the effect of elevated pCO2 on plants, the phytoplankton could change their carbon to nitrogen ratios, which will effect the feeding of the planktonic grazers. The seasonal depletion of stratospheric ozone has resulted in elevated fluxes of UVB radiation superimposed on the normal seasonal variation. Present surface UV fluxes have a significant impact on phytoplankton physiology, including the inhibition of the light and dark reactions of photosynthesis, inhibition of nitrogenase activity, inhibition of heterocyst formation, reduction in motility, increased synthesis of the UV-screening pigment scytonemin, and mutation. After reviewing these issues, recent work in our lab on measuring the effect of UV radiation on phytoplankton in the San Francisco Bay Estuary will be presented.

  4. Plant responses, climate pivot points, and trade-offs in water-limited ecosystems

    Science.gov (United States)

    Munson, S. M.; Bunting, E.

    2017-12-01

    Ecosystem transitions and thresholds are conceptually well-defined and have become a framework to address vegetation response to climate change and land-use intensification, yet there are few approaches to define the environmental conditions which can lead to them. We demonstrate a novel climate pivot point approach using long-term monitoring data from a broad network of permanent plots, satellite imagery, and experimental treatments across the southwestern U.S. The climate pivot point identifies conditions that lead to decreased plant performance and serves as an early warning sign of increased vulnerability of crossing a threshold into an altered ecosystem state. Plant responses and climate pivot points aligned with the lifespan and structural characteristics of species, were modified by soil and landscape attributes of a site, and had non-linear dynamics in some cases. Species with strong increases in abundance when water was available were most susceptible to losses during water shortages, reinforcing plant energetic and physiological tradeoffs. Future research to uncover the heterogeneity of plant responses and climate pivot points at multiple scales can lead to greater understanding of shifts in ecosystem productivity and vulnerability to climate change.

  5. Ecosystem restoration: a systems approach to exotic plant control

    Science.gov (United States)

    Karl D. Smith

    1998-01-01

    Ecosystem restoration is a systems approach because it relates to all of the thousands of interrelated and interacting systems within the ecosystem. Ecosystem restoration also changes your role in the forest from observer to participant. Some of the goals of ecosystem restoration are to improve the health, vigor, and diversity of the ecosystem--and these goals can and...

  6. Resins production: batch plant automation

    International Nuclear Information System (INIS)

    Banti, M.; Mauri, G.

    1996-01-01

    Companies that look for automation in their plants without external resources, have at their disposal flexible, custom and easy to use DCS, open towards PLC. In this article it is explained why Hoechts has followed this way of new plants for resins production automation

  7. Evaluation of Environmental Quality Productive Ecosystem Guayas (Ecuador).

    Science.gov (United States)

    Pozo, Wilson; Pardo, Francisco; Sanfeliu, Teófilo; Carrera, Gloria; Jordan, Manuel; Bech, Jaume; Roca, Núria

    2015-04-01

    Natural resources are deteriorating very rapidly in the Gulf of Guayaquil and the area of influence in the Guayas Basin due to human activity. Specific problems are generated by the mismanagement of the aquaculture industry affecting the traditional agricultural sectors: rice, banana, sugarcane, cocoa, coffee, and soya also studied, and by human and industrial settlements. The development of industrial activities such as aquaculture (shrimp building for shrimp farming in ponds) and agriculture, have increasingly contributed to the generation of waste, degrading and potentially toxic elements in high concentrations, which can have adverse effects on organisms in the ecosystems, in the health of the population and damage the ecological and environmental balance. The productive Guayas ecosystem, consists of three interrelated ecosystems, the Gulf of Guayaquil, the Guayas River estuary and the Guayas Basin buffer. The objective of this study was to evaluate the environmental quality of the productive Guayas ecosystem (Ecuador), through operational and specific objectives: 1) Draw up the transition coastal zone in the Gulf of Guayaquil, 2) Set temporal spatial variability of soil salinity in wetlands rice, Lower Guayas Basin, 3) evaluate the heavy metals in wetland rice in the Lower Basin of Guayas. The physical and chemical parameters of the soils have been studied. These are indicators of environmental quality. The multivariate statistical method showed the relations of similarities and dissimilarities between variables and parameter studies as stable. Moreover, the boundaries of coastal transition areas, temporal spatial variability of soil salinity and heavy metals in rice cultivation in the Lower Basin of Guayas were researched. The sequential studies included and discussed represent a broad framework of fundamental issues that has been valued as a basic component of the productive Guayas ecosystem. They are determinants of the environmental quality of the Guayas

  8. Changes in ecosystem services associated with planting structures of cropland: A case study in Minle County in China

    Science.gov (United States)

    Liu, Yaqun; Song, Wei; Mu, Fengyun

    2017-12-01

    The cropland ecosystem provides essential direct and indirect products and services to mankind such as food, fiber, biodiversity and soil conservation. A change of crop planting structure can change the ecosystem services of cropland by affecting land use type. In recent years, under the influence of regional comparative advantage and consumer demand changes, the crop planting structure in China has changed rapidly. However, there is still a lack of deep understanding on the effect of such a change in planting structure on the ecosystem services of cropland. Therefore, this research selected Minle County in the Heihe River Basin, which has small scattered croplands and a complex planting structure, as a study area. Based on the key time phase and optimal threshold of the normalized difference vegetation index (NDVI) data of the Thematic Mapper and Enhanced Thematic Mapper Plus (TM/ETM+) images, this study used the decision tree algorithm to classify and extract the crop planting structure in Minle County in 2007 and 2012 and to analyze the changes in its temporal and spatial patterns. Then, the market value method was adopted to estimate the effect of the change in crop planting structure on the ecosystem services of the cropland. From 2007 to 2012, the planting area of corn and rapeseed in Minle County increased by 5.86 × 103 ha and 5.10 × 103 ha, respectively. Conversely, the planting area of wheat and barley was reduced by 3.26 × 103 ha and 6.34 × 103 ha, respectively. These changes directly caused the increase of the ecosystem services value of corn and rapeseed by 1062.82 × 104 USD and 842.54 × 104 USD, respectively. The resulting reduction in the ecosystem services value of wheat and barley was 488.24 × 104 USD and 828.29 × 104 USD, respectively. Besides, the total ecosystem services value of cropland increased by 1564.98 × 104 USD. Further analysis found that the change in the crop planting structure caused an increase in the ecosystem services

  9. Plant diversity surpasses plant functional groups and plant productivity as driver of soil biota in the long term.

    Directory of Open Access Journals (Sweden)

    Nico Eisenhauer

    2011-01-01

    Full Text Available One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments.We studied changes in the impacts of plant diversity and presence of key functional groups on soil biota by investigating the performance of soil microorganisms and soil fauna two, four and six years after the establishment of model grasslands. The results indicate that temporal changes of plant community effects depend on the trophic affiliation of soil animals: plant diversity effects on decomposers only occurred after six years, changed little in herbivores, but occurred in predators after two years. The results suggest that plant diversity, in terms of species and functional group richness, is the most important plant community property affecting soil biota, exceeding the relevance of plant above- and belowground productivity and the presence of key plant functional groups, i.e. grasses and legumes, with the relevance of the latter decreasing in time.Plant diversity effects on biota are not only due to the presence of key plant functional groups or plant productivity highlighting the importance of diverse and high-quality plant derived resources, and supporting the validity of the singular hypothesis for soil biota. Our results demonstrate that in the long term plant diversity essentially drives the performance of soil biota questioning the paradigm that belowground communities are not affected by plant diversity and reinforcing the importance of biodiversity for ecosystem functioning.

  10. Soil ecosystem functioning under climate change: plant species and community effects

    Energy Technology Data Exchange (ETDEWEB)

    Kardol, Paul [ORNL; Cregger, Melissa [ORNL; Campany, Courtney E [ORNL; Classen, Aimee T [ORNL

    2010-01-01

    Feedbacks of terrestrial ecosystems to climate change depend on soil ecosystem dynamics. Soil ecosystems can directly and indirectly respond to climate change. For example, warming directly alters microbial communities by increasing their activity. Climate change may also alter plant community composition, thus indirectly altering the microbial communities that feed on their inputs. To better understand how climate change may directly and indirectly alter soil ecosystem functioning, we investigated old-field plant community and soil ecosystem responses to single and combined effects of elevated [CO2], warming, and water availability. Specifically, we collected soils at the plot level (plant community soils), and beneath dominant plant species (plant-specific soils). We used microbial enzyme activities and soil nematodes as indicators for soil ecosystem functioning. Our study resulted in two main findings: 1) Overall, while there were some interactions, water, relative to increases in [CO2] and warming, had the largest impact on plant community composition, soil enzyme activities, and soil nematodes. Multiple climate change factors can interact to shape ecosystems, but in this case, those interactions were largely driven by changes in water availability. 2) Indirect effects of climate change, via changes in plant communities, had a significant impact on soil ecosystem functioning and this impact was not obvious when looking at plant community soils. Climate change effects on enzyme activities and soil nematode abundance and community structure strongly differed between plant community soils and plant-specific soils, but also within plant-specific soils. In sum, these results indicate that accurate assessments of climate change impacts on soil ecosystem functioning require incorporating the concurrent changes in plant function and plant community composition. Climate change-induced shifts in plant community composition will likely modify or counteract the direct

  11. Ecosystem Service of Shade Trees on Nutrient Cycling and Productivity of Coffee Agro-ecosystems

    Directory of Open Access Journals (Sweden)

    Rusdi Evizal

    2009-05-01

    Full Text Available Shade trees are significant in certification scheme of sustainable coffee production. They play an importance role on ecosystem functioning. This research is aimed to study ecosystem service of shade trees in some coffee agro-ecosystems particularly on nutrient cycling and land productivity. Four agro-ecosys tems of Robusta coffee (Coffea canephora, namely sun coffee (without shade trees, coffee shaded by Michelia champaca, coffee shaded by Gliricidia sepium, and coffee shaded by Erythrina indica are evaluated during 2007—2008. Smallholder coffee plantation in Sumberjaya Subdistrict, West Lampung, which managed under local standard were employed using Randomized Complete Block Design with 3 replications. The result showed that litter fall dynamic from shade trees and from coffee trees was influenced by rainfall. Shade trees decreased weed biomass while increased litter fall production. In dry season, shade trees decreased litter fall from coffee shaded by M. champaca. G. sepium and E. indica shaded coffee showed higher yield than sun coffee and M. champaca shaded coffee. Except for M. champaca shaded coffee, yield had positive correlation (r = 0.99 with litter fall production and had negative correlation (r = —0.82 with weed biomass production. Biomass production (litter fall + weed of sun coffee and shaded coffee was not significantly different. Litter fall of shade trees had significance on nutrient cycle mainly to balance the lost of nitrogen in coffee bean harvesting.Key Words: Coffea canephora, Michelia champaca, Gliricidia sepium, Erythrina indica, litter production, nutrient cycle, coffee yield.

  12. Plant responses to precipitation in desert ecosystems: integrating functional types, pulses, thresholds, and delays.

    Science.gov (United States)

    Ogle, Kiona; Reynolds, James F

    2004-10-01

    The 'two-layer' and 'pulse-reserve' hypotheses were developed 30 years ago and continue to serve as the standard for many experiments and modeling studies that examine relationships between primary productivity and rainfall variability in aridlands. The two-layer hypothesis considers two important plant functional types (FTs) and predicts that woody and herbaceous plants are able to co-exist in savannas because they utilize water from different soil layers (or depths). The pulse-reserve model addresses the response of individual plants to precipitation and predicts that there are 'biologically important' rain events that stimulate plant growth and reproduction. These pulses of precipitation may play a key role in long-term plant function and survival (as compared to seasonal or annual rainfall totals as per the two-layer model). In this paper, we re-evaluate these paradigms in terms of their generality, strengths, and limitations. We suggest that while seasonality and resource partitioning (key to the two-layer model) and biologically important precipitation events (key to the pulse-reserve model) are critical to understanding plant responses to precipitation in aridlands, both paradigms have significant limitations. Neither account for plasticity in rooting habits of woody plants, potential delayed responses of plants to rainfall, explicit precipitation thresholds, or vagaries in plant phenology. To address these limitations, we integrate the ideas of precipitation thresholds and plant delays, resource partitioning, and plant FT strategies into a simple 'threshold-delay' model. The model contains six basic parameters that capture the nonlinear nature of plant responses to pulse precipitation. We review the literature within the context of our threshold-delay model to: (i) develop testable hypotheses about how different plant FTs respond to pulses; (ii) identify weaknesses in the current state-of-knowledge; and (iii) suggest future research directions that will

  13. Modular Engineering of Production Plants

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth

    1998-01-01

    Based on a case-study on design of pharmaceutical production plants, this paper suggests that modularity may support business efficiency for companies with one-of-a-kind production and without in-house manufacturing. Modularity may support efficient management of design knowledge and may facilitate...

  14. The Limits of Acclimation of land plants in a Terrestrial Ecosystems Model

    Science.gov (United States)

    Kothavala, Zavareh

    2014-05-01

    In this study, we examine the role of the terrestrial carbon cycle and the ability of different plant types to acclimate to a changing climate at the centennial scale using a global ecosystems model with updated biogeochemical processes related to moisture, carbon, and nitrogen. Elevated level of atmospheric carbon dioxide (CO2) increases CO2 fertilization, resulting in more CO2 uptake by vegetation, whereas the concomitant warming increases autotrophic and heterotrophic respiration, releasing CO2 to the atmosphere. Additionally, warming will enhance photosynthesis if current temperatures are below the optimal temperature for plant growth, while it will reduce photosynthesis if current temperatures are above the optimal temperature for plant growth. We present a series of ensemble simulations to evaluate the ability of plants to acclimate to changing conditions over the last century and how this affects the terrestrial carbon sink. A set of experiments related to (a) the varying relationship between CO2 fertilization and the half saturation constant, (b) the factors related to gross primary productivity and maintenance respiration, and (c) the variables related to heterotrophic respiration, were conducted with thirteen plant functional types. The experiments were performed using the Terrestrial Ecosystem Model (TEM) with a present-day vegetation distribution without the effects of natural or human disturbance, and a closed Nitrogen cycle, at a half-degree resolution over the globe. The experiment design consisted of eight scenarios that are consistent with past and future ecosystem conditions, presented in other scientific studies. The significance of model trends related to runoff, soil moisture, soil carbon, Net Primary Productivity (NPP), crop yield, and Net Ecosystem Productivity (NEP) for different seasons, as well as surface temperature, precipitation, vapor pressure, and photosynthetically active radiation are analyzed for various ecosystems at the global

  15. TRANSGENIC PLANTS: ENVIRONMENTAL PERSISTENCE AND EFFECTS ON SOIL AND PLANT ECOSYSTEMS

    Science.gov (United States)

    The genetic engineering of plants has facilitated the production of valuable agricultural and forestry crops. Transgenic plants have been created that have increased resistance to pests, herbicides, pathogens, and environmental stress, enhanced qualitative and quantitative trait...

  16. Biodiversity influences plant productivity through niche-efficiency.

    Science.gov (United States)

    Liang, Jingjing; Zhou, Mo; Tobin, Patrick C; McGuire, A David; Reich, Peter B

    2015-05-05

    The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity-ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche-efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche-efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species' inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.

  17. Biodiversity influences plant productivity through niche–efficiency

    Science.gov (United States)

    Liang, Jingjing; Zhou, Mo; Tobin, Patrick C.; McGuire, A. David; Reich, Peter B.

    2015-01-01

    The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity–ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche–efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche–efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species’ inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.

  18. Biodiversity influences plant productivity through niche–efficiency

    Science.gov (United States)

    Liang, Jingjing; Zhou, Mo; Tobin, Patrick C.; McGuire, A. David; Reich, Peter B.

    2015-01-01

    The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity–ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche–efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche–efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species’ inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty. PMID:25901325

  19. Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem.

    Science.gov (United States)

    Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

    2014-01-01

    The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems.

  20. Using life strategies to explore the vulnerability of ecosystem services to invasion by alien plants

    NARCIS (Netherlands)

    Vicente, J.; Pinro, A.; Araujo, M.; Lomba, A.; Randin, C.; Guisan, A.; Honrado, J.; Verburg, P.H.

    2013-01-01

    Invasive plants can have different effects on ecosystem functioning and on the provision of ecosystem services, with the direction and magnitude of such effects depending on the service and ecosystem being considered, but also on the life strategies of the invaders. Strategies can influence

  1. Integrating forest products with ecosystem services: a global perspective

    Science.gov (United States)

    Robert L. Deal; Rachel. White

    2012-01-01

    Around the world forests provide a broad range of vital ecosystem services. Sustainable forest management and forest products play an important role in global carbon management, but one of the major forestry concerns worldwide is reducing the loss of forestland from development. Currently, deforestation accounts for approximately 20% of total greenhouse gas emissions....

  2. Biodiversity and ecosystem processes: lessons from nature to improve management of planted forests for REDD-plus

    Science.gov (United States)

    Ian D. Thompson; Kimiko Okabe; John A. Parrotta; David I. Forrester; Eckehard Brockerhoff; Hervé Jactel; Hisatomo Taki

    2014-01-01

    Planted forests are increasingly contributing wood products and other ecosystem services at a global scale. These forests will be even more important as carbon markets develop and REDD-plus forest programs (forests used specifically to reduce atmospheric emissions of CO2 through deforestation and forest degradation) become common. Restoring degraded and deforested...

  3. Declining plant nitrogen supply and carbon accumulation in ageing primary boreal forest ecosystems

    Science.gov (United States)

    Högberg, Mona N.; Yarwood, Stephanie A.; Trumbore, Susan; Högberg, Peter

    2016-04-01

    Boreal forest soils are commonly characterized by a low plant nitrogen (N) supply. A high tree below-ground allocation of carbon (C) to roots and soil microorganisms in response to the shortage of N may lead to high microbial immobilisation of N, thus aggravating the N limitation. We studied the N supply at a Swedish boreal forest ecosystem chronosequence created by new land rising out of the sea due to iso-static rebound. The youngest soils develop with meadows by the coast, followed by a zone of dinitrogen fixing alder trees, and primary boreal conifer forest on ground up to 560 years old. With increasing ecosystem age, the proportion of microbial C out of the total soil C pool from the youngest to the oldest coniferous ecosystem was constant (c. 1-1.5%), whereas immobilised N (microbial N out of total soil N) increased and approached the levels commonly observed in similar boreal coniferous forests (c. 6-7 %), whereas gross N mineralization declined. Simultaneously, plant foliar N % decreased and the natural abundance of N-15 in the soil increased. More specifically, the difference in N-15 between plant foliage and soil increased, which is related to greater retention of N-15 relative to N-14 by ectomycorrhizal fungi as N is taken up from the soil and some N is transferred to the plant host. In the conifer forest, where these changes were greatest, we found increased fungal biomass in the F- and H-horizons of the mor-layer, in which ectomycorrhizal fungi are known to dominate (the uppermost horizon with litter and moss is dominated by saprotrophic fungi). Hence, we propose that the decreasing N supply to the plants and the subsequent decline in plant production in ageing boreal forests is linked to high tree belowground C allocation to C limited ectomycorrhizal fungi (and other soil microorganisms), a strong sink for available soil N. Data on organic matter C-14 suggested that the largest input of recently fixed plant C occurred in the younger coniferous forest

  4. Ecosystem Responses To Plant Phenology Across Scales And Trophic Levels

    Science.gov (United States)

    Stoner, D.; Sexton, J. O.; Nagol, J. R.; Ironside, K.; Choate, D.; Longshore, K.; Edwards, T., Jr.

    2015-12-01

    Plant phenology in arid and semi-arid ecoregions is constrained by water availability and governs the life history characteristics of primary and secondary consumers. We related the behavior, demography, and distribution of mammalian herbivores and their principal predator to remotely sensed vegetation and climatological indices across the western United States for the period 2000-2014. Across scales, terrain and topographic position moderates the effects of climatological drought on primary productivity, resulting in differential susceptibility among plant functional types to water stress. At broad scales, herbivores tie parturition to moist sites during the period of maximum increase in local forage production. Consequently, juvenile mortality is highest in regions of extreme phenological variability. Although decoupled from primary production by one or more trophic levels, carnivore home range size and density is negatively correlated to plant productivity and growing season length. At the finest scales, predation influences the behavior of herbivore prey through compromised habitat selection, in which maternal females trade nutritional benefits of high plant biomass for reduced mortality risk associated with increased visibility. Climate projections for the western United States predict warming combined with shifts in the timing and form of precipitation. Our analyses suggest that these changes will propagate through trophic levels as increased phenological variability and shifts in plant distributions, larger consumer home ranges, altered migration behavior, and generally higher volatility in wildlife populations. Combined with expansion and intensification of human land use across the region, these changes will likely have economic implications stemming from increased human-wildlife conflict (e.g., crop damage, vehicle collisions) and changes in wildlife-related tourism.

  5. Maintaining ecosystem services through continued livestock production on California rangelands

    Science.gov (United States)

    Barry, S.; Becchetti, T.

    2015-12-01

    Nearly 40% of California is rangeland comprising the largest land type in California and providing forage for livestock, primarily beef cattle. In addition to forage, rangelands provide a host of ecosystem systems services, including habitat for common and endangered species, fire fuels management, pollination services, clean water, viewsheds, and carbon sequestration. Published research has documented that most of these ecosystem services are positively impacted by managed livestock grazing and rancher stewardship. Ranchers typically do not receive any monetary reimbursement for their stewardship in providing these ecosystem services to the public. Markets have been difficult to establish with limited ability to adequately monitor and measure services provided. At the same time, rangelands have been experiencing rapid conversion to urbanization and more profitable and intensive forms of agriculture such as almond and walnut orchards. To prevent further conversion of rangelands and the loss of the services they provide, there needs to be a mechanism to identify and compensate landowners for the value of all products and services being received from rangelands. This paper considers two methods (opportunity cost and avoided cost) to determine the value of Payment for Ecosystem Services (PES) for rangelands. PES can raise the value of rangelands, making them more competitive financially. Real estate values and University of California Cooperative Extension Cost Studies, were used to demonstrate the difference in value (lost opportunity cost) between the primary products of rangelands (livestock production) and the products of the converted rangelands (almond and walnut orchards). Avoided costs for vegetation management and habitat creation and maintenance were used to establish the value of managed grazing. If conversion is to be slowed or stopped and managed grazing promoted to protect the ecosystem services rangelands provide, this value could be compensated through

  6. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  7. Plant senescence and crop productivity

    DEFF Research Database (Denmark)

    Gregersen, Per L.; Culetic, Andrea; Boschian, Luca

    2013-01-01

    Senescence is a developmental process which in annual crop plants overlaps with the reproductive phase. Senescence might reduce crop yield when it is induced prematurely under adverse environmental conditions. This review covers the role of senescence for the productivity of crop plants....... With the aim to enhance productivity, a number of functional stay-green cultivars have been selected by conventional breeding, in particular of sorghum and maize. In many cases, a positive correlation between leaf area duration and yield has been observed, although in a number of other cases, stay...... plants, the expression of the IPT gene under control of senescence-associated promoters has been the most successful. The promoters employed for senescence-regulated expression contain cis-elements for binding of WRKY transcription factors and factors controlled by abscisic acid. In most crops...

  8. Alert Systems for production Plants

    DEFF Research Database (Denmark)

    Nielsen, Thomas Dyhre; Jensen, Finn Verner

    2005-01-01

    We present a new methodology for detecting faults and abnormal behavior in production plants. The methodology stems from a joint project with a Danish energy consortium. During the course of the project we encountered several problems that we believe are common for projects of this type. Most...

  9. Ecological Performances of Plant Species of Halophilous Hydromorphic Ecosystems

    Directory of Open Access Journals (Sweden)

    Maria Speranza

    2015-12-01

    Full Text Available Coastal wetlands are very special environments, characterized by soils permanently or seasonally saturated by salt or brackish water. They host microorganisms and plants able to adapt to anoxic conditions. This paper proposes a review of recent scientific papers dealing with the study of coastal wetlands from different points of view. Some studies examine the species composition and the pattern of the spatial distribution of plant communities, depending on the depth of the salt water table, as well as on other related factors. A significant number of studies analyse instead the coastal wetlands in their ability for the phytoremediation (phytostabilisation and/or phytoextraction and highlight the importance of interactions between the rhizosphere of the halophytes and the physical environment. Finally, more recent studies consider the plant species of the coastal wetlands as a source of useful products (food, feed, oils and expose the results of promising researches on their cultivation.

  10. Water use, productivity and interactions among desert plants

    Energy Technology Data Exchange (ETDEWEB)

    Ehleringer, J.R.

    1992-11-17

    Water plays a central role affecting all aspects of the dynamics in aridland ecosystems. Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. The ecological studies in this project revolve around one fundamental premise: that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process. In contrast, hydrogen is not fractionated during water uptake through the root. Soil water availability in shallow, deep, and/or groundwater layers vary spatially; therefore hydrogen isotope ratios of xylem sap provide a direct measure of the water source currently used by a plant. The longer-term record of carbon and hydrogen isotope ratios is recorded annually in xylem tissues (tree rings). The research in this project addresses variation in stable isotopic composition of aridland plants and its consequences for plant performance and community-level interactions.

  11. Water use, productivity and interactions among desert plants

    Energy Technology Data Exchange (ETDEWEB)

    Ehleringer, J.R.

    1992-11-17

    Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

  12. Water use, productivity and interactions among desert plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ehleringer, J.R.

    1992-11-17

    Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

  13. Restoration of Degraded Salt Affected Lands to Productive Forest Ecosystem

    Science.gov (United States)

    Singh, Yash; Singh, Gurbachan; Singh, Bajrang; Cerdà, Artemi

    2017-04-01

    time but it appears to be driven by two parallel sets of ameliorative mechanisms like (i) fertility building process associated with organic matter addition, nitrogen accretion and nutrient recycling (ii) sodicity alleviation process driven by improved leaching that lead to reduced soil dispersion and less sodium toxicity. The index of these changes in the soil depends on the age of the forest. The present paper is based on the 15 years field study conducted to find out the rate and time that is required to achieve the status at par with a reference site of natural forest of the region, a stage where aim of degraded salt affected soils may be diverted to productive forest ecosystem. Changes in soil properties were recorded under canopy of various aged plantations. Most of the leguminous species raised on degraded sodic soils rendered an appreciable reduction in soil pH and exchangeable sodium (ESP), decrease in bulk density and increasing in soil porosity and water holding capacity. Exchangeable K, Ca, Mg and organic carbon content increased with plant growth and age. As a result of afforestation, a significant increase in soil organic matter (4 times) and decrease in pH from 10.2 to 8.6 were recorded. Total available N was increased 2-4 times in forested soil in comparison to barren soil. Acknowledgements. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 603498 (RECARE project) References. Brevik, E. C., Cerdà, A., Mataix-Solera, J., Pereg, L., Quinton, J. N., Six, J., and Van Oost, K. 2015. The interdisciplinary nature of SOIL, SOIL, 1, 117-129, doi:10.5194/soil-1-117-2015 Celentano, D., G. X. Rousseau, V. L. Engel, M. Zelarayán, E. C. Oliveira, A. C. M. Araujo, and E. G. de Moura. 2016. Degradation of Riparian Forest Affects Soil Properties and Ecosystem Services Provision in Eastern Amazon of Brazil. Land Degradation and Development. doi:10.1002/ldr.2547

  14. Regional signatures of plant response to drought and elevated temperature across a desert ecosystem

    Science.gov (United States)

    Munson, Seth M.; Muldavin, Esteban H.; Belnap, Jayne; Peters, Debra P.C.; Anderson, John P.; Reiser, M. Hildegard; Gallo, Kirsten; Melgoza-Castillo, Alicia; Herrick, Jeffrey E.; Christiansen, Tim A.

    2013-01-01

    The performance of many desert plant species in North America may decline with the warmer and drier conditions predicted by climate change models, thereby accelerating land degradation and reducing ecosystem productivity. We paired repeat measurements of plant canopy cover with climate at multiple sites across the Chihuahuan Desert over the last century to determine which plant species and functional types may be the most sensitive to climate change. We found that the dominant perennial grass, Bouteloua eriopoda, and species richness had nonlinear responses to summer precipitation, decreasing more in dry summers than increasing with wet summers. Dominant shrub species responded differently to the seasonality of precipitation and drought, but winter precipitation best explained changes in the cover of woody vegetation in upland grasslands and may contribute to woody-plant encroachment that is widespread throughout the southwestern United States and northern Mexico. Temperature explained additional variability of changes in cover of dominant and subdominant plant species. Using a novel empirically based approach we identified ‘‘climate pivot points’’ that were indicative of shifts from increasing to decreasing plant cover over a range of climatic conditions. Reductions in cover of annual and several perennial plant species, in addition to declines in species richness below the long-term summer precipitation mean across plant communities, indicate a decrease in the productivity for all but the most drought-tolerant perennial grasses and shrubs in the Chihuahuan Desert. Overall, our regional synthesis of long-term data provides a robust foundation for forecasting future shifts in the composition and structure of plant assemblages in the largest North American warm desert.

  15. Seasonal shift in net ecosystem production in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.S.P.; Nair, S.; Chandramohan, D.

    ) and community respiration (R). Measurements of these variables are a prerequisite to assess the trophic status of aquatic ecosystems. Del Giorgio et al. (1997) suggested that metabolic balance depends on the primary productivity of the system. The rate...), and heterotrophy is not restricted to oligotrophic sys- tems. Of late, there has been considerable debate on the role of planktonic communities as sources (del Giorgio et al. 1997; Duarte et al. 2001) or sinks (Williams 1998) of carbon in subtropical and temperate...

  16. Plutonium in a grassland ecosystem. [Rocky Flats Plant

    Energy Technology Data Exchange (ETDEWEB)

    Little, C.A.

    1976-08-01

    A study was made of plutonium contamination of grassland at the Rocky Flats plant northwest of Denver, Colorado. Of interest were: the definition of major plutonium-containing ecosystem compartments; the relative amounts in those compartments; how those values related to studies done in other geographical areas; whether or not the predominant isotopes, /sup 238/Pu and /sup 239/Pu, behaved differently; and what mechanisms might have allowed for the observed patterns of contamination. Samples of soil, litter, vegetation, arthropods, and small mammals were collected for Pu analysis and mass determination from each of two macroplots. Small aliquots (5 g or less) were analyzed by a rapid liquid scintillation technique and by alpha spectrometry. Of the compartments sampled, greater than 99 percent of the total plutonium was contained in the soil and the concentrations were significantly inversely correlated with distance from the contamination source, depth of the sample, and particle size of the sieved soil samples. The soil data suggested that the distribution of contamination largely resulted from physical transport processes.

  17. Rapid ecosystem shifts in peatlands: linking plant physiology and succession.

    Science.gov (United States)

    Granath, Gustaf; Strengbom, Joachim; Rydin, Håkan

    2010-10-01

    Stratigraphic records from peatlands suggest that the shift from a rich fen (calcareous fen) to an ombrotrophic bog can occur rapidly. This shift constitutes a switch from a species-rich ecosystem to a species-poor one with greater carbon storage. In this process, the invasion and expansion of acidifying bog species of Sphagnum (peat mosses) play a key role. To test under what conditions an acidifying bog species could invade a rich fen, we conducted three experiments, contrasting the bog species S. fucsum with the rich-fen species S. warnstorfii and S. teres. We first tested the effect of calcareous water by growing the three species at different constant height above the water table (HWT; 2, 7, and 14 cm) in a rich-fen pool and measured maximum photosynthetic rate and production and difference in length growth as an indicator of competition. In none of the species was the photosynthetic capacity negatively affected when placed at low HWT, but S. fuscum was a weaker competitor at low HWT. In our second experiment we transplanted the three species into microhabitats with different and naturally varying HWT in a rich fen. Here, S. fuscum nearly ceased to photosynthesize when transplanted to low HWT (brown moss carpet), while it performed similarly to the two rich-fen species at the intermediate level (S. warnstorfii hummock level). In contrast to S. fuscum, the rich-fen sphagna performed equally well in both habitats. The brown moss carpet was seasonally flooded, and in our third experiment we found that S. fuscum, but not S. teres, was severely damaged when submerged in rich-fen water. Our results suggest two thresholds in HWT affecting the ecosystem switch: one level that reduces the risk of submergence and a higher one that makes bog sphagna competitive against the rich-fen species.

  18. Using ecological production functions to link ecological processes to ecosystem services.

    Science.gov (United States)

    Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem services (ES) production. Although EPFs are acknowledged as being essential to improve environmental management, their use in ecological risk assessment has received relatively ...

  19. Potential Effects of Organic Carbon Production on Ecosystems and Drinking Water Quality

    Directory of Open Access Journals (Sweden)

    Larry R. Brown

    2003-10-01

    Full Text Available Restoration of tidal wetlands in the Sacramento-San Joaquin Delta (Delta is an important component of the Ecosystem Restoration Program of the CALFED Bay-Delta Program (CALFED. CALFED is a collaborative effort among state and federal agencies to restore the ecological health and improve water management of the Delta and San Francisco Bay (Bay. Tidal wetland restoration is intended to provide valuable habitat for organisms and to improve ecosystem productivity through export of various forms of organic carbon, including both algae and plant detritus. However, the Delta also provides all or part of the drinking water for over 22 million Californians. In this context, increasing sources of organic carbon may be a problem because of the potential increase in the production of trihalomethanes and other disinfection by-products created during the process of water disinfection. This paper reviews the existing information about the roles of organic carbon in ecosystem function and drinking water quality in the Bay-Delta system, evaluates the potential for interaction, and considers major uncertainties and potential actions to reduce uncertainty. In the last 10 years, substantial progress has been made on the role of various forms of organic carbon in both ecosystem function and drinking water quality; however, interactions between the two have not been directly addressed. Several ongoing studies are beginning to address these interactions, and the results from these studies should reduce uncertainty and provide focus for further research.

  20. Regional scale prioritisation for key ecosystem services, renewable energy production and urban development.

    Directory of Open Access Journals (Sweden)

    Stefano Casalegno

    Full Text Available Although the importance of addressing ecosystem service benefits in regional land use planning and decision-making is evident, substantial practical challenges remain. In particular, methods to identify priority areas for the provision of key ecosystem services and other environmental services (benefits from the environment not directly linked to the function of ecosystems need to be developed. Priority areas are locations which provide disproportionally high benefits from one or more service. Here we map a set of ecosystem and environmental services and delineate priority areas according to different scenarios. Each scenario is produced by a set of weightings allocated to different services and corresponds to different landscape management strategies which decision makers could undertake. Using the county of Cornwall, U.K., as a case study, we processed gridded maps of key ecosystem services and environmental services, including renewable energy production and urban development. We explored their spatial distribution patterns and their spatial covariance and spatial stationarity within the region. Finally we applied a complementarity-based priority ranking algorithm (zonation using different weighting schemes. Our conclusions are that (i there are two main patterns of service distribution in this region, clustered services (including agriculture, carbon stocks, urban development and plant production and dispersed services (including cultural services, energy production and floods mitigation; (ii more than half of the services are spatially correlated and there is high non-stationarity in the spatial covariance between services; and (iii it is important to consider both ecosystem services and other environmental services in identifying priority areas. Different weighting schemes provoke drastic changes in the delineation of priority areas and therefore decision making processes need to carefully consider the relative values attributed to

  1. Regional scale prioritisation for key ecosystem services, renewable energy production and urban development.

    Science.gov (United States)

    Casalegno, Stefano; Bennie, Jonathan J; Inger, Richard; Gaston, Kevin J

    2014-01-01

    Although the importance of addressing ecosystem service benefits in regional land use planning and decision-making is evident, substantial practical challenges remain. In particular, methods to identify priority areas for the provision of key ecosystem services and other environmental services (benefits from the environment not directly linked to the function of ecosystems) need to be developed. Priority areas are locations which provide disproportionally high benefits from one or more service. Here we map a set of ecosystem and environmental services and delineate priority areas according to different scenarios. Each scenario is produced by a set of weightings allocated to different services and corresponds to different landscape management strategies which decision makers could undertake. Using the county of Cornwall, U.K., as a case study, we processed gridded maps of key ecosystem services and environmental services, including renewable energy production and urban development. We explored their spatial distribution patterns and their spatial covariance and spatial stationarity within the region. Finally we applied a complementarity-based priority ranking algorithm (zonation) using different weighting schemes. Our conclusions are that (i) there are two main patterns of service distribution in this region, clustered services (including agriculture, carbon stocks, urban development and plant production) and dispersed services (including cultural services, energy production and floods mitigation); (ii) more than half of the services are spatially correlated and there is high non-stationarity in the spatial covariance between services; and (iii) it is important to consider both ecosystem services and other environmental services in identifying priority areas. Different weighting schemes provoke drastic changes in the delineation of priority areas and therefore decision making processes need to carefully consider the relative values attributed to different services.

  2. Amino acid production exceeds plant nitrogen demand in Siberian tundra

    Science.gov (United States)

    Wild, Birgit; Eloy Alves, Ricardo J.; Bárta, Jiři; Čapek, Petr; Gentsch, Norman; Guggenberger, Georg; Hugelius, Gustaf; Knoltsch, Anna; Kuhry, Peter; Lashchinskiy, Nikolay; Mikutta, Robert; Palmtag, Juri; Prommer, Judith; Schnecker, Jörg; Shibistova, Olga; Takriti, Mounir; Urich, Tim; Richter, Andreas

    2018-03-01

    Arctic plant productivity is often limited by low soil N availability. This has been attributed to slow breakdown of N-containing polymers in litter and soil organic matter (SOM) into smaller, available units, and to shallow plant rooting constrained by permafrost and high soil moisture. Using 15N pool dilution assays, we here quantified gross amino acid and ammonium production rates in 97 active layer samples from four sites across the Siberian Arctic. We found that amino acid production in organic layers alone exceeded literature-based estimates of maximum plant N uptake 17-fold and therefore reject the hypothesis that arctic plant N limitation results from slow SOM breakdown. High microbial N use efficiency in organic layers rather suggests strong competition of microorganisms and plants in the dominant rooting zone. Deeper horizons showed lower amino acid production rates per volume, but also lower microbial N use efficiency. Permafrost thaw together with soil drainage might facilitate deeper plant rooting and uptake of previously inaccessible subsoil N, and thereby promote plant productivity in arctic ecosystems. We conclude that changes in microbial decomposer activity, microbial N utilization and plant root density with soil depth interactively control N availability for plants in the Arctic.

  3. A dynamic model to assess tradeoffs in power production and riverine ecosystem protection.

    Science.gov (United States)

    Miara, Ariel; Vörösmarty, Charles J

    2013-06-01

    Major strategic planning decisions loom as society aims to balance energy security, economic development and environmental protection. To achieve such balance, decisions involving the so-called water-energy nexus must necessarily embrace a regional multi-power plant perspective. We present here the Thermoelectric Power & Thermal Pollution Model (TP2M), a simulation model that simultaneously quantifies thermal pollution of rivers and estimates efficiency losses in electricity generation as a result of fluctuating intake temperatures and river flows typically encountered across the temperate zone. We demonstrate the model's theoretical framework by carrying out sensitivity tests based on energy, physical and environmental settings. We simulate a series of five thermoelectric plants aligned along a hypothetical river, where we find that warm ambient temperatures, acting both as a physical constraint and as a trigger for regulatory limits on plant operations directly reduce electricity generation. As expected, environmental regulation aimed at reducing thermal loads at a single plant reduces power production at that plant, but ironically can improve the net electricity output from multiple plants when they are optimally co-managed. On the technology management side, high efficiency can be achieved through the use of natural gas combined cycle plants, which can raise the overall efficiency of the aging population of plants, including that of coal. Tradeoff analysis clearly shows the benefit of attaining such high efficiencies, in terms of both limiting thermal loads that preserve ecosystem services and increasing electricity production that benefits economic development.

  4. Uranium hexafluoride production plant decommissioning

    International Nuclear Information System (INIS)

    Santos, Ivan

    2008-01-01

    The Institute of Energetic and Nuclear Research - IPEN is a research and development institution, located in a densely populated area, in the city of Sao Paulo. The nuclear fuel cycle was developed from the Yellow Cake to the enrichment and reconversion at IPEN. After this phase, all the technology was transferred to private enterprises and to the Brazilian Navy (CTM/SP). Some plants of the fuel cycle were at semi-industrial level, with a production over 20 kg/h. As a research institute, IPEN accomplished its function of the fuel cycle, developing and transferring technology. With the necessity of space for the implementation of new projects, the uranium hexafluoride (UF 6 ) production plant was chosen, since it had been idle for many years and presented potential leaking risks, which could cause environmental aggression and serious accidents. This plant decommission required accurate planning, as this work had not been carried out in Brazil before, for this type of facility, and there were major risks involving gaseous hydrogen fluoride aqueous solution of hydrofluoric acid (HF) both highly corrosive. Evaluations were performed and special equipment was developed, aiming to prevent leaking and avoid accidents. During the decommissioning work, the CNEN safety standards were obeyed for the whole operation. The environmental impact was calculated, showing to be not relevant.The radiation doses, after the work, were within the limits for the public and the area was released for new projects. (author)

  5. Phytoplankton primary production in the world's estuarine-coastal ecosystems

    Science.gov (United States)

    Cloern, James E.; Foster, S.Q.; Kleckner, A.E.

    2014-01-01

    Estuaries are biogeochemical hot spots because they receive large inputs of nutrients and organic carbon from land and oceans to support high rates of metabolism and primary production. We synthesize published rates of annual phytoplankton primary production (APPP) in marine ecosystems influenced by connectivity to land – estuaries, bays, lagoons, fjords and inland seas. Review of the scientific literature produced a compilation of 1148 values of APPP derived from monthly incubation assays to measure carbon assimilation or oxygen production. The median value of median APPP measurements in 131 ecosystems is 185 and the mean is 252 g C m−2 yr−1, but the range is large: from −105 (net pelagic production in the Scheldt Estuary) to 1890 g C m−2 yr−1 (net phytoplankton production in Tamagawa Estuary). APPP varies up to 10-fold within ecosystems and 5-fold from year to year (but we only found eight APPP series longer than a decade so our knowledge of decadal-scale variability is limited). We use studies of individual places to build a conceptual model that integrates the mechanisms generating this large variability: nutrient supply, light limitation by turbidity, grazing by consumers, and physical processes (river inflow, ocean exchange, and inputs of heat, light and wind energy). We consider method as another source of variability because the compilation includes values derived from widely differing protocols. A simulation model shows that different methods reported in the literature can yield up to 3-fold variability depending on incubation protocols and methods for integrating measured rates over time and depth. Although attempts have been made to upscale measures of estuarine-coastal APPP, the empirical record is inadequate for yielding reliable global estimates. The record is deficient in three ways. First, it is highly biased by the large number of measurements made in northern Europe (particularly the Baltic region) and North America. Of the 1148

  6. Pharmaceuticals and Personal-Care Products in Plants.

    Science.gov (United States)

    Bartrons, Mireia; Peñuelas, Josep

    2017-03-01

    Pharmaceuticals and personal-care products (PPCPs) derived from agricultural, urban, and industrial areas accumulate in plants at concentrations (ng to μg kg -1 ) that can be toxic to the plants. Importantly, the dietary intake of these PPCP-contaminated plants may also pose a risk to human health, but currently little is known about the fate of PPCPs in plants and their effect on or risk to the ecosystem. In this Opinion article we propose that in-depth research on the use of plants as a monitoring device for assessing the use and environmental presence of PPCPs is warranted. The toxicity of PPCPs to plants and their microbiota needs to be established, as well as any toxic effects on herbivores including humans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Ecosystem development in roadside grasslands: Biotic control, plant-soil interactions, and dispersal limitations

    Science.gov (United States)

    Garcia-Palacios, P.; Bowker, M.A.; Maestre, F.T.; Soliveres, S.; Valladares, F.; Papadopoulos, J.; Escudero, A.

    2011-01-01

    Roadside grasslands undergoing secondary succession are abundant, and represent ecologically meaningful examples of novel, human-created ecosystems. Interactions between plant and soil communities (hereafter plant-soil interactions) are of major importance in understanding the role of biotic control in ecosystem functioning, but little is known about these links in the context of ecosystem restoration and succession. The assessment of the key biotic communities and interactions driving ecosystem development will help practitioners to better allocate the limited resources devoted to roadside grassland restoration. We surveyed roadside grasslands from three successional stages (0-2, 7-9, and > 20 years) in two Mediterranean regions of Spain. Structural equation modeling was used to evaluate how interactions between plants, biological soil crusts (BSCs), and soil microbial functional diversity (soil microorganisms) affect indicators of ecosystem development and restoration: plant similarity to the reference ecosystem, erosion control, and soil C storage and N accumulation. Changes in plant community composition along the successional gradient exerted the strongest influence on these indicators. High BSC cover was associated with high soil stability, and high soil microbial functional diversity from late-successional stages was associated with high soil fertility. Contrary to our expectations, the indirect effects of plants, mediated by either BSCs or soil microorganisms, were very weak in both regions, suggesting a minor role for plant-soil interactions upon ecosystem development indicators over long periods. Our results suggest that natural vegetation dynamics effectively improved ecosystem development within a time frame of 20 years in the grasslands evaluated. They also indicate that this time could be shortened if management actions focus on: (1) maintaining wellconserved natural areas close to roadsides to enhance plant compositional changes towards late

  8. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    OpenAIRE

    Mo Shuqing; Zhang Xiufeng; Tang Yali; Liu Zhengwen; Kettridge Nicholas

    2017-01-01

    Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aer...

  9. Characterizing isotopic variability of primary production and consumers in Great Plains ecosystems during protracted regional drought

    Science.gov (United States)

    Haveles, A. W.; Fox-Dobbs, K.; Talmadge, K. A.; Fetrow, A.; Fox, D. L.

    2012-12-01

    Over the last few years (2010-2012), the Great Plains of the central USA experienced protracted drought conditions, including historically severe drought during Summer, 2011. Drought severity in the region generally decreases with increasing latitude, but episodic drought is a fundamental trait of grassland ecosystems. Documenting above ground energy and nutrient flow with current drought is critical to understanding responses of grassland ecosystems in the region to predicted increased episodicity of rainfall and recurrence of drought due to anthropogenic climate change. Characterization of biogeochemical variability of modern ecosystems at the microhabitat, local landscape, and regional scales is also necessary to interpret biogeochemical records of ancient grasslands based on paleosols and fossil mammals. Here, we characterize three grassland ecosystems that span the drought gradient in the Great Plains (sites in the Texas panhandle, southwest Kansas, and northwest Nebraska). We measured δ13C and δ15N values of plants and consumers to characterize the biogeochemical variability within each ecosystem. Vegetation at each site is a mix of trees, shrubs, herbs, and cool- and warm-growing season grasses (C3 and C4, respectively). Thus, consumers have access to isotopically distinct sources of forage that vary in abundance with microhabitat (e.g., open grassland, shrub thicket, riparian woodland). Observations indicate herbivorous arthropod (grasshoppers and crickets) abundance follows drought severity, with high abundance of many species in Texas, and low abundance of few species in Nebraska. Small mammal (rodents) abundance follows the inverse pattern with 0.8%, 3.2% and 17.2% capture success in Texas, Kansas and Nebraska, respectively. The inverse abundance patterns of consumer groups may result from greater sensitivity of small mammal consumers with high metabolic needs to lower local net primary productivity and forage quality under drought conditions. As a

  10. Asymmetric warming significantly affects net primary production, but not ecosystem carbon balances of forest and grassland ecosystems in northern China.

    Science.gov (United States)

    Su, Hongxin; Feng, Jinchao; Axmacher, Jan C; Sang, Weiguo

    2015-03-13

    We combine the process-based ecosystem model (Biome-BGC) with climate change-scenarios based on both RegCM3 model outputs and historic observed trends to quantify differential effects of symmetric and asymmetric warming on ecosystem net primary productivity (NPP), heterotrophic respiration (Rh) and net ecosystem productivity (NEP) of six ecosystem types representing different climatic zones of northern China. Analysis of covariance shows that NPP is significant greater at most ecosystems under the various environmental change scenarios once temperature asymmetries are taken into consideration. However, these differences do not lead to significant differences in NEP, which indicates that asymmetry in climate change does not result in significant alterations of the overall carbon balance in the dominating forest or grassland ecosystems. Overall, NPP, Rh and NEP are regulated by highly interrelated effects of increases in temperature and atmospheric CO2 concentrations and precipitation changes, while the magnitude of these effects strongly varies across the six sites. Further studies underpinned by suitable experiments are nonetheless required to further improve the performance of ecosystem models and confirm the validity of these model predictions. This is crucial for a sound understanding of the mechanisms controlling the variability in asymmetric warming effects on ecosystem structure and functioning.

  11. Asymmetric warming significantly affects net primary production, but not ecosystem carbon balances of forest and grassland ecosystems in northern China

    Science.gov (United States)

    Su, Hongxin; Feng, Jinchao; Axmacher, Jan C.; Sang, Weiguo

    2015-03-01

    We combine the process-based ecosystem model (Biome-BGC) with climate change-scenarios based on both RegCM3 model outputs and historic observed trends to quantify differential effects of symmetric and asymmetric warming on ecosystem net primary productivity (NPP), heterotrophic respiration (Rh) and net ecosystem productivity (NEP) of six ecosystem types representing different climatic zones of northern China. Analysis of covariance shows that NPP is significant greater at most ecosystems under the various environmental change scenarios once temperature asymmetries are taken into consideration. However, these differences do not lead to significant differences in NEP, which indicates that asymmetry in climate change does not result in significant alterations of the overall carbon balance in the dominating forest or grassland ecosystems. Overall, NPP, Rh and NEP are regulated by highly interrelated effects of increases in temperature and atmospheric CO2 concentrations and precipitation changes, while the magnitude of these effects strongly varies across the six sites. Further studies underpinned by suitable experiments are nonetheless required to further improve the performance of ecosystem models and confirm the validity of these model predictions. This is crucial for a sound understanding of the mechanisms controlling the variability in asymmetric warming effects on ecosystem structure and functioning.

  12. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.

    Directory of Open Access Journals (Sweden)

    Adam E Vorsino

    Full Text Available Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75 as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1. This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.

  13. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates

    Science.gov (United States)

    Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; `Ohukani`ohi`a Gon, Sam; Koob, Gregory A.

    2014-01-01

    Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.

  14. Hyperspectral Remote Sensing of Terrestrial Ecosystem Productivity from ISS

    Science.gov (United States)

    Huemmrich, K. F.; Campbell, P. K. E.; Gao, B. C.; Flanagan, L. B.; Goulden, M.

    2017-12-01

    Data from the Hyperspectral Imager for Coastal Ocean (HICO), mounted on the International Space Station (ISS), were used to develop and test algorithms for remotely retrieving ecosystem productivity. The ISS orbit introduces both limitations and opportunities for observing ecosystem dynamics. Twenty six HICO images were used from four study sites representing different vegetation types: grasslands, shrubland, and forest. Gross ecosystem production (GEP) data from eddy covariance were matched with HICO-derived spectra. Multiple algorithms were successful relating spectral reflectance with GEP, including: Spectral Vegetation Indices (SVI), SVI in a light use efficiency model framework, spectral shape characteristics through spectral derivatives and absorption feature analysis, and statistical models leading to Multiband Hyperspectral Indices (MHI) from stepwise regressions and Partial Least Squares Regression (PLSR). Algorithms were able to achieve r2 better than 0.7 for both GEP at the overpass time and daily GEP. These algorithms were successful using a diverse set of observations combining data from multiple years, multiple times during growing season, different times of day, with different view angles, and different vegetation types. The demonstrated robustness of the algorithms presented in this study over these conditions provides some confidence in mapping spatial patterns of GEP, describing variability within fields as well as the regional patterns based only on spectral reflectance information. The ISS orbit provides periods with multiple observations collected at different times of the day within a period of a few days. Diurnal GEP patterns were estimated comparing the half-hourly average GEP from the flux tower against HICO estimates of GEP (r2=0.87) if morning, midday, and afternoon observations were available for average fluxes in the time period.

  15. Fractionation of Nitrogen Isotopes by Plants with Different Types of Mycorrhiza in Mountain Tundra Ecosystems

    Science.gov (United States)

    Buzin, Igor; Makarov, Mikhail; Maslov, Mikhail; Tiunov, Alexei

    2017-04-01

    We studied nitrogen concentration and nitrogen isotope composition in plants from four mountain tundra ecosystems in the Khibiny Mountains. The ecosystems consisted of a toposequence beginning with the shrub-lichen heath (SLH) on the ridge and upper slope, followed by the Betula nana dominated shrub heath (SH) on the middle slope, the cereal meadow (CM) on the lower slope and the sedge meadow (SM) at the bottom of the slope. The inorganic nitrogen concentration of the soils from the studied ecosystems were significantly different; the SLH soil was found to contain the minimum concentration of N-NH4+ and N-NO3- , while in the soils of the meadow ecosystems these concentrations were much higher. The concentration of nitrogen in leaves of the dominant plant species in all of the ecosystems is directly connected with the concentration of inorganic nitrogen in the soils, regardless of the plant's mycorrhizal symbiosis type. However, such a correlation is not apparent in the case of plant roots, especially for plant roots with ectomycorrhiza and ericoid mycorrhiza. The majority of plant species with these types of mycorrhiza in the SH and particularly in the CM were enriched in 15N in comparison with the SLH (such plants were not found within the SM). This could be due to several reasons: 1) the decreasing role of mycorrhiza in nitrogen consumption and therefore in the fractionation of isotopes in the relatively-N-enriched ecosystems; 2) the use of relatively-15N-enriched forms of nitrogen for plant nutrition in meadow ecosystems. This heavier nitrogen isotope composition in plant roots with ectomycorrhiza and ericoid mycorrhiza in ecosystems with available nitrogen enriched soils doesn't correspond to the classical idea of mycorrhiza decreasing participation in nitrogen plant nutrition. The analysis of the isotope composition of separate labile forms of nitrogen makes it possible to explain the phenomenon. Not all arbuscular mycorrhizal species within the sedge meadow

  16. Problem of a radiocapacity in a system soil-plant for bog ecosystem

    International Nuclear Information System (INIS)

    Kutlakhmedova-Vyshnyakova, V.

    1998-01-01

    The factors of the various components of a pasture bog ecosystem were evaluated on the example of the Volynsk area. Soil and water were found to contribute appreciably to the accumulation of radionuclides in plants in the bog ecosystem. Evaluation of the integral distribution of radionuclides ( 137 Cs) and the radiocapacity factors of the bog ecosystem components lead to F(soil) = 0.5, F(water) = 0.1, F(plants) = 0.25, and F(root) = 0.15. The radiocapacity factor determines the fraction of radionuclides from a general reserve concentrated in a particular component of the ecosystem. The higher values transfer factors of accumulation for plants in the bog ecosystem in comparison with terrestrial ecosystems (Tf 1.5-18) are noteworthy. Thus the contribution of soil to the formation Tf is from 60 % to 80 %, the remaining pathway in plants being from the water phase. This may be related with the high radiocapacity of soil in the bog ecosystem and (as a corollary) the rather small concentration of radionuclides in water in comparison with soil

  17. Peak season plant activity shift towards spring is reflected by increasing carbon uptake by extratropical ecosystems.

    Science.gov (United States)

    Gonsamo, Alemu; Chen, Jing M; Ooi, Ying W

    2018-05-01

    Climate change is lengthening the growing season of the Northern Hemisphere extratropical terrestrial ecosystems, but little is known regarding the timing and dynamics of the peak season of plant activity. Here, we use 34-year satellite normalized difference vegetation index (NDVI) observations and atmospheric CO 2 concentration and δ 13 C isotope measurements at Point Barrow (Alaska, USA, 71°N) to study the dynamics of the peak of season (POS) of plant activity. Averaged across extratropical (>23°N) non-evergreen-dominated pixels, NDVI data show that the POS has advanced by 1.2 ± 0.6 days per decade in response to the spring-ward shifts of the start (1.0 ± 0.8 days per decade) and end (1.5 ± 1.0 days per decade) of peak activity, and the earlier onset of the start of growing season (1.4 ± 0.8 days per decade), while POS maximum NDVI value increased by 7.8 ± 1.8% for 1982-2015. Similarly, the peak day of carbon uptake, based on calculations from atmospheric CO 2 concentration and δ 13 C data, is advancing by 2.5 ± 2.6 and 4.3 ± 2.9 days per decade, respectively. POS maximum NDVI value shows strong negative relationships (p POS days. Given that the maximum solar irradiance and day length occur before the average POS day, the earlier occurrence of peak plant activity results in increased plant productivity. Both the advancing POS day and increasing POS vegetation greenness are consistent with the shifting peak productivity towards spring and the increasing annual maximum values of gross and net ecosystem productivity simulated by coupled Earth system models. Our results further indicate that the decline in autumn NDVI is contributing the most to the overall browning of the northern high latitudes (>50°N) since 2011. The spring-ward shift of peak season plant activity is expected to disrupt the synchrony of biotic interaction and exert strong biophysical feedbacks on climate by modifying the surface albedo and energy budget. © 2017

  18. Threatened plant resources: distribution and ecosystem services in the world's high elevation park of the karakoram ranges

    International Nuclear Information System (INIS)

    Shedayi, A.; Xu, M.; Hussain, F.; Sadia, S.; Bano, S.

    2016-01-01

    sustainable use. Awareness for sustainable harvesting of plants, reducing grazing pressure, equitable resource sharing, marketing of the products, effective management and policy decisions and research on ecosystem services assessment, valuation and climate change impact on wild plant resources are recommended. (author)

  19. Productivity growth patterns in US dairy products manufacturing plants

    NARCIS (Netherlands)

    Geylani, P.C.; Stefanou, S.E.

    2011-01-01

    We analyse the productivity growth patterns in the US dairy products industry using the Census Bureau's plant-level data set. We decompose Total Factor Productivity (TFP) growth into the scale and technical change components and analyse variability of plants' productivity by constructing transition

  20. Beyond barriers: ecosystem functions of alien aquatic plants

    NARCIS (Netherlands)

    Grutters, Bart M.C.

    2017-01-01

    Human impacts have become a dominant force in shaping Earth’s biosphere. One major consequence is the global reshuffling of species, both through intentional introductions, but also unintentional because human infrastructure benefits the movement of certain species. Consequently, ecosystems are

  1. Simulation of the decomposition and nitrogen mineralization of aboveground plant material in two unfertilized grassland ecosystems.

    NARCIS (Netherlands)

    Bloemhof, H.S.; Berendse, F.

    1995-01-01

    A simple model of the decomposition and nitrogen mineralization of plant material from two unfertilized grassland ecosystems has been developed, with only the proportion of leaves and stems in the original material, the initial nitrogen contents of these plant parts and temperature as input data.

  2. Fine Scale ANUClimate Data for Ecosystem Modeling and Assessment of Plant Functional Types

    Science.gov (United States)

    Hutchinson, M. F.; Kesteven, J. L.; Xu, T.; Evans, B. J.; Togashi, H. F.; Stein, J. L.

    2015-12-01

    High resolution spatially extended values of climate variables play a central role in the assessment of climate and projected future climate in ecosystem modeling. The ground based meteorological network remains a key resource for deriving these spatially extended climate variables. We report on the production, and applications, of new anomaly based fine scale spatial interpolations of key climate variables at daily and monthly time scale, across the Australian continent. The methods incorporate several innovations that have significantly improved spatial predictive accuracy, as well as providing a platform for the incorporation of additional remotely sensed data. The interpolated climate data are supporting many continent-wide ecosystem modeling applications and are playing a key role in testing optimality hypotheses associated with plant functional types (PFTs). The accuracy, and robustness to data error, of anomaly-based interpolation has been enhanced by incorporating physical process aspects of the different climate variables and employing robust statistical methods implemented in the ANUSPLIN package. New regression procedures have also been developed to estimate "background" monthly climate normals from all stations with minimal records to substantially increase the density of supporting spatial networks. Monthly mean temperature interpolation has been enhanced by incorporating process based coastal effects that have reduced predictive error by around 10%. Overall errors in interpolated monthly temperature fields are around 25% less than errors reported by an earlier study. For monthly and daily precipitation, a new anomaly structure has been devised to take account of the skewness in precipitation data and the large proportion of zero values that present significant challenges to standard interpolation methods. The many applications include continent-wide Gross Primary Production modeling and assessing constraints on light and water use efficiency derived

  3. The potential of novel native plant materials for the restoration of novel ecosystems

    Directory of Open Access Journals (Sweden)

    T.A. Jones

    2015-05-01

    Full Text Available Abstract Extensive ecological change has been sustained by many dryland ecosystems throughout the world, resulting in conversion to so-called novel ecosystems. It is within such ecological contexts that native plant materials destined for ecological applications must be able to function. In the Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis [Beetle & A.M. Young] S.L. Welsh ecosystems of the Intermountain West, for example, novel ecosystem structure and functioning are pervasive. Invasive species, particularly annual grasses, fuel repeated wildfires that drive previously stable ecosystem states across thresholds to less desirable states that are highly recalcitrant to restoration efforts. Structural changes include reductions of native flora, damage to biological soil crusts, and alterations to soil microbiota. Functional changes include altered hydrologic and nutrient cycling, leading to permanent losses of soil organic matter and nitrogen that favor the invaders. We argue that there is an important place in restoration for plant materials that are novel and/or non-local that have been developed to be more effective in the novel ecosystems for which they are intended, thus qualifying them as “ecologically appropriate.” Such plant materials may be considered as an alternative to natural/local “genetically appropriate” plant materials, which are sometimes deemed best adapted due to vetting by historical evolutionary processes.

  4. Synoptic events force biological productivity in Patagonian fjord ecosystems

    Science.gov (United States)

    Daneri, Giovanni

    2016-04-01

    an extremely productive bloom of the dinoflagellate Heterocapsa sp. in July 2014, after the passage of a synoptic low pressure front provided, for the first time, strong evidence that phytoplankton blooming in the Patagonian fjord ecosystems is controlled by synoptic processes and that they are not limited by light as previously reported. This research was funded by COPAS Sur-Austral (PFB-31) and FONDECYT 1131063

  5. Impacts of light shading and nutrient enrichment geo-engineering approaches on the productivity of a stratified, oligotrophic ocean ecosystem.

    Science.gov (United States)

    Hardman-Mountford, Nick J; Polimene, Luca; Hirata, Takafumi; Brewin, Robert J W; Aiken, Jim

    2013-12-06

    Geo-engineering proposals to mitigate global warming have focused either on methods of carbon dioxide removal, particularly nutrient fertilization of plant growth, or on cooling the Earth's surface by reducing incoming solar radiation (shading). Marine phytoplankton contribute half the Earth's biological carbon fixation and carbon export in the ocean is modulated by the actions of microbes and grazing communities in recycling nutrients. Both nutrients and light are essential for photosynthesis, so understanding the relative influence of both these geo-engineering approaches on ocean ecosystem production and processes is critical to the evaluation of their effectiveness. In this paper, we investigate the relationship between light and nutrient availability on productivity in a stratified, oligotrophic subtropical ocean ecosystem using a one-dimensional water column model coupled to a multi-plankton ecosystem model, with the goal of elucidating potential impacts of these geo-engineering approaches on ecosystem production. We find that solar shading approaches can redistribute productivity in the water column but do not change total production. Macronutrient enrichment is able to enhance the export of carbon, although heterotrophic recycling reduces the efficiency of carbon export substantially over time. Our results highlight the requirement for a fuller consideration of marine ecosystem interactions and feedbacks, beyond simply the stimulation of surface blooms, in the evaluation of putative geo-engineering approaches.

  6. Natural Ecosystem Surrounding a Conventional Banana Crop Improves Plant Health and Fruit Quality

    Directory of Open Access Journals (Sweden)

    Florence P. Castelan

    2018-06-01

    Full Text Available Natural ecosystems near agricultural landscapes may provide rich environments for growing crops. However, the effect of a natural ecosystem on crop health and fruit quality is poorly understood. In the present study, it was investigated whether the presence of a natural ecosystem surrounding a crop area influences banana plant health and fruit postharvest behavior. Plants from two conventional banana crop areas with identical planting time and cultural practices were used; the only difference between banana crop areas is that one area was surrounded by a natural forest (Atlantic forest fragment (Near-NF, while the other area was inserted at the center of a conventional banana crop (Distant-NF. Results showed that bananas harvested from Near-NF showed higher greenlife and a more homogeneous profile during ripening compared to fruits harvested from Distant-NF. Differences in quality parameters including greenlife, carbohydrate profile, and pulp firmness between fruits harvested from Near-NF and Distant-NF are explained, at least partly, by differences in the balance of plant growth regulators (indole-3-acetic acid and abscisic acid in bananas during ripening. Furthermore, plants from Near-NF showed a lower severity index of black leaf streak disease (BLSD and higher levels of phenolic compounds in leaves compared to plants from Distant-NF. Together, the results provide additional evidence on how the maintenance of natural ecosystems near conventional crop areas could be a promising tool to improve plant health and fruit quality.

  7. Plant species richness regulates soil respiration through changes in productivity.

    Science.gov (United States)

    Dias, André Tavares Corrêa; van Ruijven, Jasper; Berendse, Frank

    2010-07-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of diversity on soil respiration. We hypothesized that plant diversity could affect soil respiration in two ways. On the one hand, more diverse plant communities have been shown to promote plant productivity, which could increase soil respiration. On the other hand, the nutrient concentration in the biomass produced has been shown to decrease with diversity, which could counteract the production-induced increase in soil respiration. Our results clearly show that soil respiration increased with species richness. Detailed analysis revealed that this effect was not due to differences in species composition. In general, soil respiration in mixtures was higher than would be expected from the monocultures. Path analysis revealed that species richness predominantly regulates soil respiration through changes in productivity. No evidence supporting the hypothesized negative effect of lower N concentration on soil respiration was found. We conclude that shifts in productivity are the main mechanism by which changes in plant diversity may affect soil respiration.

  8. Plant species and functional group combinations affect green roof ecosystem functions.

    Science.gov (United States)

    Lundholm, Jeremy; Macivor, J Scott; Macdougall, Zachary; Ranalli, Melissa

    2010-03-12

    Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. We used a replicated modular extensive (shallow growing- medium) green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or facilitation as mechanisms governing biodiversity-ecosystem functioning relationships in green

  9. Radiocontamination patterns of vascular plants in a forest ecosystem

    International Nuclear Information System (INIS)

    Nimis, P.L.; Bolognini, G.; Giovani, C.

    1994-01-01

    This study is based on measurements of radiocesium and potassium-40 in leaves, stems and roots of 48 vascular plants in a natural beech forest in the Carnic Alps (NE Italy). The data have been submitted to numerical classification, and the main results are: (a) radiocontamination patterns and ecology of the species are well related, (b) three main groups of species with different radiocontamination can be distinguished: plants in clearings, forest plants rooting in the organic soil layer, forest plants rooting in the mineral layer; (c) radiocesium tends to be retained in the roots, especially in plants in the clearings; (d) Pteridophytes, contrary to all other plants, are able to discriminate between cesium and potassium at leaf level; (e) for all other species, cesium and potassium, once taken up by the plant, exhibit a similar behaviour; (f) total contamination by radiocesium is related to the depth of the root systems, and to the unequal distribution of radiocesium in the soil profile. Species-specific mechanisms of differential absorption are not evident in the investigated forest; the radiocontamination of plants can be easily explained in ecological terms. Radiocontamination on a water basis (Bq/l) is suggested as being much more appropriate for solving certain radioecological problems

  10. Wildland fire in ecosystems: fire and nonnative invasive plants

    Science.gov (United States)

    Kristin Zouhar; Jane Kapler Smith; Steve Sutherland; Matthew L. Brooks

    2008-01-01

    This state-of-knowledge review of information on relationships between wildland fire and nonnative invasive plants can assist fire managers and other land managers concerned with prevention, detection, and eradication or control of nonnative invasive plants. The 16 chapters in this volume synthesize ecological and botanical principles regarding relationships between...

  11. Invasive exotic plant species in Sierra Nevada ecosystems

    Science.gov (United States)

    Carla M. D' Antonio; Eric L. Berlow; Karen L. Haubensak

    2004-01-01

    The Sierra Nevada is a topographically and floristically diverse region of the western United States. While it comprises only a fifth of the total land area of California, half of the native plant species in the state occur within the range. In addition, more than 400 plant species are endemic to the Sierra Nevada and many of these are listed as threatened or have...

  12. Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem

    OpenAIRE

    Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

    2014-01-01

    The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate associatio...

  13. Can observed ecosystem responses to elevated CO2 and N fertilisation be explained by optimal plant C allocation?

    Science.gov (United States)

    Stocker, Benjamin; Prentice, I. Colin

    2016-04-01

    The degree to which nitrogen availability limits the terrestrial C sink under rising CO2 is a key uncertainty in carbon cycle and climate change projections. Results from ecosystem manipulation studies and meta-analyses suggest that plant C allocation to roots adjusts dynamically under varying degrees of nitrogen availability and other soil fertility parameters. In addition, the ratio of biomass production to GPP appears to decline under nutrient scarcity. This reflects increasing plant C export into the soil and to symbionts (Cex) with decreasing nutrient availability. Cex is consumed by an array of soil organisms and may imply an improvement of nutrient availability to the plant. These concepts are left unaccounted for in Earth system models. We present a model for the coupled cycles of C and N in grassland ecosystems to explore optimal plant C allocation under rising CO2 and its implications for the ecosystem C balance. The model follows a balanced growth approach, accounting for the trade-offs between leaf versus root growth and Cex in balancing C fixation and N uptake. We further model a plant-controlled rate of biological N fixation (BNF) by assuming that Cex is consumed by N2-fixing processes if the ratio of Nup:Cex falls below the inverse of the C cost of N2-fixation. The model is applied at two temperate grassland sites (SwissFACE and BioCON), subjected to factorial treatments of elevated CO2 (FACE) and N fertilization. Preliminary simulation results indicate initially increased N limitation, evident by increased relative allocation to roots and Cex. Depending on the initial state of N availability, this implies a varying degree of aboveground growth enhancement, generally consistent with observed responses. On a longer time scale, ecosystems are progressively released from N limitation due tighter N cycling. Allowing for plant-controlled BNF implies a quicker release from N limitation and an adjustment to more open N cycling. In both cases, optimal plant

  14. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-01-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3. Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r2 = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m−2) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (ΔNPP/ΔN) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2. Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. PMID:24604779

  15. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests.

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-08-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2 ) and tropospheric ozone (O3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3 . Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r(2) = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m(-2) ) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆NPP/∆N) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2 . Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. © 2014 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  16. The phenology of gross ecosystem productivity and ecosystem respiration in temperate hardwood and conifer chronosequences

    Science.gov (United States)

    A. Noormets

    2009-01-01

    The relative duration of active and dormant seasons has a strong influence on ecosystem net carbon balance and its carbon uptake potential. While recognized as an important source of temporal and spatial variability, the seasonality of ecosystem carbon balance has not been studied explicitly, and still lacks standard terminology. In the current chapter, we apply a...

  17. Countermeasures for reduction of radioactive contamination of farm animals and animal products in agricultural ecosystems

    International Nuclear Information System (INIS)

    Poeschl, M.

    2006-01-01

    Contamination of food products reaching the consumer may be a serious problem following radioactive contamination deposited in the agricultural environment. A wide variety of measures is available to reduce or prevent the transfer of radionuclides through the food-chain and hence reduce the radiation dose to the consumer. This paper reviews both literature sources and practice of applying agricultural countermeasures: Interventions at the soil-plant step, at the plant-animal step, and at the foodstuff-man step. In practice, the most effective countermeasures which can be used to reduce radionuclide contamination of animals in agricultural ecosystems will be obtained by a combination of both management changes and the use of chemical binders to prevent gut absorption. Social, economic, and practical considerations of the countermeasures such as availability, technical feasibility, acceptability and side-effects need to be also taken into account. (authors)

  18. Redefining plant systems biology: from cell to ecosystem

    NARCIS (Netherlands)

    Keurentjes, J.J.B.; Angenent, G.C.; Dicke, M.; Martins Dos Santos, V.A.P.; Molenaar, J.; Van der Putten, W.H.; de Ruiter, P.C.; Struik, P.C.; Thomma, B.P.H.J.

    2011-01-01

    Molecular biologists typically restrict systems biology to cellular levels. By contrast, ecologists define biological systems as communities of interacting individuals at different trophic levels that process energy, nutrient and information flows. Modern plant breeding needs to increase

  19. Developing microbe-plant interactions for applications in plant-growth promotion and disease control, production of useful compounds, remediation, and carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.H.; Bernard, S.; Andersen, G.L.; Chen, W.

    2009-03-01

    Interactions between plants and microbes are an integral part of our terrestrial ecosystem. Microbe-plant interactions are being applied in many areas. In this review, we present recent reports of applications in the areas of plant-growth promotion, biocontrol, bioactive compound and biomaterial production, remediation and carbon sequestration. Challenges, limitations and future outlook for each field are discussed.

  20. Shrubs as ecosystem engineers across an environmental gradient: effects on species richness and exotic plant invasion.

    Science.gov (United States)

    Kleinhesselink, Andrew R; Magnoli, Susan M; Cushman, J Hall

    2014-08-01

    Ecosystem-engineering plants modify the physical environment and can increase species diversity and exotic species invasion. At the individual level, the effects of ecosystem engineers on other plants often become more positive in stressful environments. In this study, we investigated whether the community-level effects of ecosystem engineers also become stronger in more stressful environments. Using comparative and experimental approaches, we assessed the ability of a native shrub (Ericameria ericoides) to act as an ecosystem engineer across a stress gradient in a coastal dune in northern California, USA. We found increased coarse organic matter and lower wind speeds within shrub patches. Growth of a dominant invasive grass (Bromus diandrus) was facilitated both by aboveground shrub biomass and by growing in soil taken from shrub patches. Experimental removal of shrubs negatively affected species most associated with shrubs and positively affected species most often found outside of shrubs. Counter to the stress-gradient hypothesis, the effects of shrubs on the physical environment and individual plant growth did not increase across the established stress gradient at this site. At the community level, shrub patches increased beta diversity, and contained greater rarified richness and exotic plant cover than shrub-free patches. Shrub effects on rarified richness increased with environmental stress, but effects on exotic cover and beta diversity did not. Our study provides evidence for the community-level effects of shrubs as ecosystem engineers in this system, but shows that these effects do not necessarily become stronger in more stressful environments.

  1. Plant functional traits and diversity in sand dune ecosystems across different biogeographic regions

    Science.gov (United States)

    Mahdavi, P.; Bergmeier, E.

    2016-07-01

    Plant species of a functional group respond similarly to environmental pressures and may be expected to act similarly on ecosystem processes and habitat properties. However, feasibility and applicability of functional groups in ecosystems across very different climatic regions have not yet been studied. In our approach we specified the functional groups in sand dune ecosystems of the Mediterranean, Hyrcanian and Irano-Turanian phytogeographic regions. We examined whether functional groups are more influenced by region or rather by habitat characteristics, and identified trait syndromes associated with common habitat types in sand dunes (mobile dunes, stabilized dunes, salt marshes, semi-wet sands, disturbed habitats). A database of 14 traits, 309 species and 314 relevés was examined and trait-species, trait-plot and species-plot matrices were built. Cluster analysis revealed similar plant functional groups in sand dune ecosystems across regions of very different species composition and climate. Specifically, our study showed that plant traits in sand dune ecosystems are grouped reflecting habitat affiliation rather than region and species pool. Environmental factors and constraints such as sand mobility, soil salinity, water availability, nutrient status and disturbance are more important for the occurrence and distribution of plant functional groups than regional belonging. Each habitat is shown to be equipped with specific functional groups and can be described by specific sets of traits. In restoration ecology the completeness of functional groups and traits in a site may serve as a guideline for maintaining or restoring the habitat.

  2. Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity

    Science.gov (United States)

    Pellegrini, Adam F. A.; Ahlström, Anders; Hobbie, Sarah E.; Reich, Peter B.; Nieradzik, Lars P.; Staver, A. Carla; Scharenbroch, Bryant C.; Jumpponen, Ari; Anderegg, William R. L.; Randerson, James T.; Jackson, Robert B.

    2018-01-01

    Fire frequency is changing globally and is projected to affect the global carbon cycle and climate. However, uncertainty about how ecosystems respond to decadal changes in fire frequency makes it difficult to predict the effects of altered fire regimes on the carbon cycle; for instance, we do not fully understand the long-term effects of fire on soil carbon and nutrient storage, or whether fire-driven nutrient losses limit plant productivity. Here we analyse data from 48 sites in savanna grasslands, broadleaf forests and needleleaf forests spanning up to 65 years, during which time the frequency of fires was altered at each site. We find that frequently burned plots experienced a decline in surface soil carbon and nitrogen that was non-saturating through time, having 36 per cent (±13 per cent) less carbon and 38 per cent (±16 per cent) less nitrogen after 64 years than plots that were protected from fire. Fire-driven carbon and nitrogen losses were substantial in savanna grasslands and broadleaf forests, but not in temperate and boreal needleleaf forests. We also observe comparable soil carbon and nitrogen losses in an independent field dataset and in dynamic model simulations of global vegetation. The model study predicts that the long-term losses of soil nitrogen that result from more frequent burning may in turn decrease the carbon that is sequestered by net primary productivity by about 20 per cent of the total carbon that is emitted from burning biomass over the same period. Furthermore, we estimate that the effects of changes in fire frequency on ecosystem carbon storage may be 30 per cent too low if they do not include multidecadal changes in soil carbon, especially in drier savanna grasslands. Future changes in fire frequency may shift ecosystem carbon storage by changing soil carbon pools and nitrogen limitations on plant growth, altering the carbon sink capacity of frequently burning savanna grasslands and broadleaf forests.

  3. Processes for manufacture of products from plants

    DEFF Research Database (Denmark)

    2010-01-01

    Disclosed herein is a process for inhibiting browning of plant material comprising adding a chelating agent to a disrupted plant material and adjusting the pH to a value of 2.0 to 4.5. Processes for manufacture of soluble and insoluble products from a plant material are also disclosed. Soluble...

  4. Productivity and modifications of ecosystem processes in gaps of a low Macchia in southern Italy

    Directory of Open Access Journals (Sweden)

    A. De Marco

    2008-06-01

    Full Text Available Disturbance in Mediterranean shrub lands creates gaps that break up the shrub cover and potentially restrict productivity and other ecosystem processes. Gaps make up to about 20% of the low Macchia area at the Castel Volturno nature reserve (southern Italy. The plant community consists mainly of small annual species (legumes, grasses and forbs that germinate in November and die out before the onset of summer drought. The inter-annual variability in productivity and the relative abundance of legumes, grasses and forbs were assessed over 4 yr (2004–2007 to evaluate main potential modifications of ecosystem processes determined by the occurrence of gaps in the shrub cover.

    In the study years, at the peak production, plant mass varied from about 250 to 700 g m−2; biomass belowground allocation varied from 23% in the wettest to 44% in the driest year. Belowground/aboveground biomass ratios were negatively related to rainfall and positively related to the length of the dry period, showing that water availability controls biomass allocation patterns. Legumes were the most abundant fraction (about 60% of the aboveground mass in the wettest year. In the drier years legumes exhibited a shorter life cycle and senesced by mid-spring. Among the three functional groups monitored, legumes were the most sensitive to water shortage and their biomass was positively related to the amount of rainfall and negatively related to the length of the dry period. The higher fraction of legume mass was associated with higher nitrogen content in plant tissues and in the soil. Senesced annual species decomposed more than senescent Phillyrea sp. leaves. The stability of organic carbon pool, evaluated through the endogenous mineralization coefficient (CEM, was lower in gaps than in understorey soils.

  5. Ecosystem and physiological controls over methane production in northern wetlands

    Science.gov (United States)

    Valentine, David W.; Holland, Elisabeth A.; Schimel, David S.

    1994-01-01

    Peat chemistry appears to exert primary control over methane production rates in the Canadian Northern Wetlands Study (NOWES) area. We determined laboratory methane production rate potentials in anaerobic slurries of samples collected from a transect of sites through the NOWES study area. We related methane production rates to indicators of resistance to microbial decay (peat C: N and lignin: N ratios) and experimentally manipulated substrate availability for methanogenesis using ethanol (EtOH) and plant litter. We also determined responses of methane production to pH and temperature. Methane production potentials declined along the gradient of sites from high rates in the coastal fens to low rates in the interior bogs and were generally highest in surface layers. Strong relationships between CH4 production potentials and peat chemistry suggested that methanogenesis was limited by fermentation rates. Methane production at ambient pH responded strongly to substrate additions in the circumneutral fens with narrow lignin: N and C: N ratios (delta CH4/delta EtOH = 0.9-2.3 mg/g) and weakly in the acidic bogs with wide C: N and lignin: N ratios (delta CH4/delta EtOH = -0.04-0.02 mg/g). Observed Q(sub 10) values ranged from 1.7 to 4.7 and generally increased with increasing substrate availability, suggesting that fermentation rates were limiting. Titration experiments generally demonstrated inhibition of methanogenesis by low pH. Our results suggest that the low rates of methane emission observed in interior bogs during NOWES likely resulted from pH and substrate quality limitation of the fermentation step in methane production and thus reflect intrinsically low methane production potentials. Low methane emission rates observed during NOWES will likely be observed in other northern wetland regions with similar vegetation chemistry.

  6. Planning product quality: An example - ornamental plants

    Directory of Open Access Journals (Sweden)

    Kovačević Miodrag

    2003-01-01

    Full Text Available The industry of ornamental plants is a subject of quality planning. The quality plan is a document setting out the specific quality practices in ornamental plants production. That plan introduce organizational structure procedures, processes and resources needed to implement quality in life cycle of product chain. For engineers it represents a new tool.

  7. Medicinal plants: production and biochemical characterization

    International Nuclear Information System (INIS)

    Chunzhao Liu; Zobayed, S.M.A; Murch, S.J.; Saxena, P.K.

    2002-01-01

    Recent advances in the area of biotechnology offer some possibility for the development of new technologies for the conservation, characterization and mass production of medicinal plant species, (i.e. in vitro cell culture techniques for the mass production of sterile, consistent, standardized medicinal plant materials). This paper discussed the following subjects - plant tissue culture, de novo shoot organogenesis, de novo root organogenesis, somatic embryogenesis, large scale propagation in bioreactors and discovery of unique biomolecules

  8. Goods and services provided by native plants in desert ecosystems: Examples from the northwestern coastal desert of Egypt

    Directory of Open Access Journals (Sweden)

    Laila M. Bidak

    2015-01-01

    Full Text Available About one third of the earth’s land surface is covered by deserts that have low and variable rainfall, nutrient-poor soils, and little vegetation cover. Here, we focus on the goods and services offered by desert ecosystems using the northwestern coastal desert of Egypt extending from Burg El-Arab to El-Salloum as an example. We conducted field surveys and collected other data to identify the goods services and provided by native plant species. A total of 322 native plant species were compiled. The direct services provided by these native plants included sources of food, medicine, and energy; indirect vegetation services included promotion of biodiversity, water storage, and soil fertility. The plant diversity in this ecosystem provided economic service benefits, such as sources of fodder, fuel-wood, and traditional medicinal plants. Changes in land use and recent ill-managed human activities may influence the availability of these services and strongly impact biodiversity and habitat availability. Although deserts are fragile and support low levels of productivity, they provide a variety of goods and services whose continuing availability is contingent upon the adoption of rational land management practices.

  9. Bioindicators of Plant and Animal Origin in an Ecosystem Evaluation

    Directory of Open Access Journals (Sweden)

    J. Žák

    2006-01-01

    Full Text Available The study had a threefold scientific objective: to perform a botanical survey of the area under study, to identify all plant species grazed by the European hare (Lepus europaeus and to determine polychlorinated biphenyl (PCB presence in hares using the screening test. The study area is characterized by intensive agricultural operations around the town of Senice in the Olomouc region. During the botanical survey in the agrocoenosis in 2001 and 2002, the author identified 62 species of herbs and grasses and 8 woody species. Of that total, 19 herbal and grass species and 6 woody species were suitable for consumption by the European hare. To determine the PCB concentrations, samples of plants, and the liver and muscle tissue from the front and hind extremities of the European hare were collected. PCB concentrations ranged from 0.0004 to 0.0007 mg in plants and 0.0001 to 0.0005 mg in the liver and musculature of hares.

  10. Small diversity effects on ocean primary production under environmental change in a diversity-resolving ocean ecosystem model

    DEFF Research Database (Denmark)

    Prowe, Friederike; Pahlow, M.; Dutkiewicz, S.

    2013-01-01

    Marine ecosystem models used to investigate how global change affects ocean ecosystems and their functioning typically omit pelagic diversity. Diversity, however, can affect functions such as primary production and their sensitivity to environmental changes. Using a global ocean ecosystem model...... the diversity effects on ecosystem functioning captured in ocean ecosystem models....

  11. Solar radiation uncorks the lignin bottleneck on plant litter decomposition in terrestrial ecosystems

    Science.gov (United States)

    Austin, A.; Ballare, C. L.; Méndez, M. S.

    2015-12-01

    Plant litter decomposition is an essential process in the first stages of carbon and nutrient turnover in terrestrial ecosystems, and together with soil microbial biomass, provide the principal inputs of carbon for the formation of soil organic matter. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in low rainfall ecosystems; however, the generality of this process as a control on carbon cycling in terrestrial ecosystems is not known, and the indirect effects of photodegradation on biotic stimulation of carbon turnover have been debated in recent studies. We demonstrate that in a wide range of plant species, previous exposure to solar radiation, and visible light in particular, enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility for microbial enzymes to plant litter carbohydrates due to a reduction in lignin content. Photodegradation of plant litter reduces the structural and chemical bottleneck imposed by lignin in secondary cell walls. In litter from woody plant species, specific interactions with ultraviolet radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized positive effect of solar radiation exposure on subsequent microbial activity is mediated by increased accessibility to cell wall polysaccharides, which suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release and the carbon balance in a broad range of terrestrial ecosystems.

  12. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Mo Shuqing

    2017-01-01

    Full Text Available Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aeruginosa and a combined treatment with both plants and snails were compared with controls to evaluate their effects on trophic state. The total nitrogen (TN, total phosphorus (TP and chlorophyll a (Chl a concentrations of planktonic and benthic algal samples were determined every two weeks, along with light intensity at the sediment surface. The plant-only treatment significantly reduced the TN levels and planktonic and benthic algal biomass and increased the light intensity at the sediment surface. The snail-only treatment reduced the concentrations of TN and reduced planktonic and benthic algal biomass. The combined treatment decreased the concentrations of TN and TP, reduced planktonic algal biomass and increased the light intensity on the sediment surface. The results indicate that while submerged plants and snails can both improve water quality, the most pronounced effect in aquatic ecosystems is achieved by their presence in combination. A combined reintroduction approach may provide enhanced benefits in restoring the eutrophic ecosystems, following the reduction of external nutrient loading.

  13. The variable effects of soil nitrogen availability and insect herbivory on aboveground and belowground plant biomass in an old-field ecosystem

    DEFF Research Database (Denmark)

    Blue, Jarrod D.; Souza, Lara; Classen, Aimée T.

    2011-01-01

    in an old-field ecosystem. In 2004, we established 36 experimental plots in which we manipulated soil nitrogen (N) availability and insect abundance in a completely randomized plot design. In 2009, after 6 years of treatments, we measured aboveground biomass and assessed root production at peak growth...... not be limiting primary production in this ecosystem. Insects reduced the aboveground biomass of subdominant plant species and decreased coarse root production. We found no statistical interactions between N availability and insect herbivory for any response variable. Overall, the results of 6 years of nutrient...

  14. Integrating plant ecological responses to climate extremes from individual to ecosystem levels.

    Science.gov (United States)

    Felton, Andrew J; Smith, Melinda D

    2017-06-19

    Climate extremes will elicit responses from the individual to the ecosystem level. However, only recently have ecologists begun to synthetically assess responses to climate extremes across multiple levels of ecological organization. We review the literature to examine how plant responses vary and interact across levels of organization, focusing on how individual, population and community responses may inform ecosystem-level responses in herbaceous and forest plant communities. We report a high degree of variability at the individual level, and a consequential inconsistency in the translation of individual or population responses to directional changes in community- or ecosystem-level processes. The scaling of individual or population responses to community or ecosystem responses is often predicated upon the functional identity of the species in the community, in particular, the dominant species. Furthermore, the reported stability in plant community composition and functioning with respect to extremes is often driven by processes that operate at the community level, such as species niche partitioning and compensatory responses during or after the event. Future research efforts would benefit from assessing ecological responses across multiple levels of organization, as this will provide both a holistic and mechanistic understanding of ecosystem responses to increasing climatic variability.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

  15. The estimation ecological risk for ground ecosystems in case of nuclear power plant failures

    International Nuclear Information System (INIS)

    Kremlenkov, D.Yu.; Kremlenkov, M.Yu.

    2004-01-01

    The results of probabilistic estimation of the damage for forest and agricultural ecosystems connected with cesium-137 and strontium-90 release during hypothetical accidents at NPPs are analyzed. The concept of radioecological risk including application of the models for radioactivity transport in atmosphere and calculation of of absorbed doses in ecosystem critical groups is used for the analysis. It is proved that the probable ecological damage expressed in terms of ecosystem destruction area depends on the scale of accidental radioisotope releases, meteorological conditions and radiation resistance of critical groups in plant associations. The conclusion is made that ecological risks expressed in the form of probable area of ecosystem destruction in the zone where dose loads lay in the range from minimal ecologically significant limit up to ecologically significant limit amount to 4-9% for conifers contaminated with cesium-137 and to 2-4% for agricultural crops contaminated with strontium-90 [ru

  16. Defining groundwater-dependent ecosystems and assessing critical water needs for their foundational plant communities

    Science.gov (United States)

    Stella, J. C.

    2017-12-01

    In many water-limited regions, human water use in conjunction with increased climate variability threaten the sustainability of groundwater-dependent plant communities and the ecosystems that depend on them (GDEs). Identifying and delineating vulnerable GDEs and determining critical functional thresholds for their foundational species has proved challenging, but recent research across several disciplines shows great promise for reducing scientific uncertainty and increasing applicability to ecosystem and groundwater management. Combining interdisciplinary approaches provides insights into indicators that may serve as early indicators of ecosystem decline, or alternatively demonstrate lags in responses depending on scale or sensitivity, or that even may decouple over time (Fig. 1). At the plant scale, miniaturization of plant sap flow sensors and tensiometers allow for non-destructive, continual measurements of plant water status in response to environmental stressors. Novel applications of proven tree-ring and stable isotope methods provide multi-decadal chronologies of radial growth, physiological function (using d13C ratios) and source water use (using d18O ratios) in response to annual variation in climate and subsurface water availability to plant roots. At a landscape scale, integration of disparate geospatial data such as hyperspectral imagery and LiDAR, as well as novel spectral mixing analysis promote the development of novel water stress indices such as vegetation greenness and non-photosynthetic (i.e., dead) vegetation (Fig. 2), as well as change detection using time series (Fig. 3). Furthermore, increases in data resolution across numerous data types can increasingly differentiate individual plant species, including sensitive taxa that serve as early warning indicators of ecosystem impairment. Combining and cross-calibrating these approaches provide insight into the full range of GDE response to environmental change, including increased climate drought

  17. Modeling the response of plants and ecosystems to elevated CO sub 2 and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth's surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society's ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  18. Modeling the response of plants and ecosystems to elevated CO{sub 2} and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth`s surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society`s ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  19. Trait- and density-mediated indirect interactions initiated by an exotic invasive plant autogenic ecosystem engineer

    Science.gov (United States)

    Dean E. Pearson

    2010-01-01

    Indirect interactions are important for structuring ecological systems. However, research on indirect effects has been heavily biased toward top-down trophic interactions, and less is known about other indirect-interaction pathways. As autogenic ecosystem engineers, plants can serve as initiators of nontrophic indirect interactions that, like top-down pathways, can...

  20. The new flora of the northeastern USA: quantifying introduced plant species occupancy in forest ecosystems

    Science.gov (United States)

    Bethany K. Schulz; Andrew N. Gray

    2013-01-01

    Introduced plant species have significant negative impacts in many ecosystems and are found in many forests around the world. Some factors linked to the distribution of introduced species include fragmentation and disturbance, native species richness, and climatic and physical conditions of the landscape. However, there are few data sources that enable the assessment...

  1. Exploring Third-Grade Student Model-Based Explanations about Plant Relationships within an Ecosystem

    Science.gov (United States)

    Zangori, Laura; Forbes, Cory T.

    2015-01-01

    Elementary students should have opportunities to develop scientific models to reason and build understanding about how and why plants depend on relationships within an ecosystem for growth and survival. However, scientific modeling practices are rarely included within elementary science learning environments and disciplinary content is often…

  2. NON-TARGET AND ECOSYSTEM IMPACTS FROM GENETICALLY MODIFIED CROPS CONTAINING PLANT INCORPORATED PROTECTANTS (PIPS)

    Science.gov (United States)

    The risk of unintended and unexpected adverse impacts on non-target organisms and ecosystems is a key issue in environmental risk assessment of PIP crop plants. While there has been considerable examination of the effects of insect resistant crops on certain non-target organisms...

  3. The effect of atmospheric carbon dioxide elevation on plant growth in freshwater ecosystems

    NARCIS (Netherlands)

    Schippers, P.; Vermaat, J.; Klein, de J.J.M.; Mooij, W.M.

    2004-01-01

    The authors developed a dynamic model to investigate the effect of atmospheric carbon dioxide (CO2) increase on plant growth in freshwater ecosystems. Steady-state simulations were performed to analyze the response of phytoplankton and submerged macrophytes to atmospheric CO2 elevation from 350 to

  4. The effect of atmospheric carbon dioxide elevation on plant growth in freshwater ecosystems

    NARCIS (Netherlands)

    Schippers, P.; Vermaat, J.E.; de Klein, J.; Mooij, W.M.

    2004-01-01

    We developed a dynamic model to investigate the effect of atmospheric carbon dioxide (CO2) increase on plant growth in freshwater ecosystems. Steady-state simulations were performed to analyze the response of phytoplankton and submerged macrophytes to atmospheric CO2 elevation from 350 to 700 ppm.

  5. Predicting ecosystem functioning from plant traits: Results from a multi-scale ecophsiological modeling approach

    NARCIS (Netherlands)

    Wijk, van M.T.

    2007-01-01

    Ecosystem functioning is the result of processes working at a hierarchy of scales. The representation of these processes in a model that is mathematically tractable and ecologically meaningful is a big challenge. In this paper I describe an individual based model (PLACO¿PLAnt COmpetition) that

  6. Diurnal patterns of productivity of arbuscular mycorrhizal fungi revealed with the Soil Ecosystem Observatory.

    Science.gov (United States)

    Hernandez, Rebecca R; Allen, Michael F

    2013-10-01

    Arbuscular mycorrhizal (AM) fungi are the most abundant plant symbiont and a major pathway of carbon sequestration in soils. However, their basic biology, including their activity throughout a 24-h day : night cycle, remains unknown. We employed the in situ Soil Ecosystem Observatory to quantify the rates of diurnal growth, dieback and net productivity of extra-radical AM fungi. AM fungal hyphae showed significantly different rates of growth and dieback over a period of 24 h and paralleled the circadian-driven photosynthetic oscillations observed in plants. The greatest rates (and incidences) of growth and dieback occurred between noon and 18:00 h. Growth and dieback events often occurred simultaneously and were tightly coupled with soil temperature and moisture, suggesting a rapid acclimation of the external phase of AM fungi to the immediate environment. Changes in the environmental conditions and variability of the mycorrhizosphere may alter the diurnal patterns of productivity of AM fungi, thereby modifying soil carbon sequestration, nutrient cycling and host plant success. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  7. Spectral filtering for plant production

    Energy Technology Data Exchange (ETDEWEB)

    Young, R.E.; McMahon, M.J.; Rajapakse, N.C.; Becoteau, D.R.

    1994-12-31

    Research to date suggests that spectral filtering can be an effective alternative to chemical growth regulators for altering plant development. If properly implemented, it can be nonchemical and environmentally friendly. The aqueous CuSO{sub 4}, and CuCl{sub 2} solutions in channelled plastic panels have been shown to be effective filters, but they can be highly toxic if the solutions contact plants. Some studies suggest that spectral filtration limited to short EOD intervals can also alter plant development. Future research should be directed toward confirmation of the influence of spectral filters and exposure times on a broader range of plant species and cultivars. Efforts should also be made to identify non-noxious alternatives to aqueous copper solutions and/or to incorporate these chemicals permanently into plastic films and panels that can be used in greenhouse construction. It would also be informative to study the impacts of spectral filters on insect and microbal populations in plant growth facilities. The economic impacts of spectral filtering techniques should be assessed for each delivery methodology.

  8. Nitrogen Uptake During Fall, Winter and Spring Differs Among Plant Functional Groups in a Subarctic Heath Ecosystem

    DEFF Research Database (Denmark)

    Larsen, Klaus Steenberg; Michelsen, Anders; Jonasson, Sven

    2012-01-01

    Nitrogen (N) is a critical resource for plant growth in tundra ecosystems, and species differences in the timing of N uptake may be an important feature regulating community composition and ecosystem productivity. We added 15N-labelled glycine to a subarctic heath tundra dominated by dwarf shrubs...... to 37 ± 7% by April indicating significant microbial N turnover prior to spring thaw. Only the evergreen dwarf shrubs showed active 15N acquisition before early May indicating that they had the highest potential of all functional groups for acquiring nutrients that became available in early spring....... The faster-growing deciduous shrubs did not resume 15N acquisition until after early May indicating that they relied more on nitrogen made available later during the spring/early summer. The graminoids and mosses had no significant increases in 15N tracer recovery or tissue 15N tracer concentrations after...

  9. Seed dispersal as an ecosystem service: frugivore loss leads to decline of a socially valued plant, Capsicum frutescens.

    Science.gov (United States)

    Egerer, Monika H; Fricke, Evan C; Rogers, Haldre S

    2018-04-01

    Species interactions, both mutualistic and antagonistic, are widely recognized as providing important ecosystem services. Fruit-eating animals influence plant recruitment by increasing germination during gut passage and moving seeds away from conspecifics. However, relative to studies focused on the importance of frugivores for plant population maintenance, few studies target frugivores as ecosystem service providers, and frugivores are underappreciated as ecosystem service providers relative to other mutualists such as pollinators. Here, we use an accidental experiment to elucidate the role of seed dispersal by frugivores for maintaining a culturally and economically important plant, the donne' sali chili (Capsicum frutescens) in the Mariana Islands. One of the islands (Guam) has lost nearly all of its native forest birds due to an invasive snake (Boiga irregularis), whereas nearby islands have relatively intact bird populations. We hypothesized that frugivore loss would influence chili recruitment and abundance, which could have economic and cultural impacts. By using video cameras, we confirmed that birds were the primary seed dispersers. We used captive bird feeding trials to obtain gut-passed seeds to use in a seedling emergence experiment. The experiment showed that gut-passed seeds emerged sooner and at a higher proportion than seeds from whole fruits. Consistent with our findings that birds benefit chilies, we observed lower chili abundance on Guam than on islands with birds. In a survey questionnaire of island residents, the majority of residents reported an association between the wild chili and local cultural values and traditions. In addition, we identified a thriving market for chili products, suggesting benefits of wild chilies to people in the Marianas both as consumers and producers. Our study therefore documents seed dispersal as both a cultural and a supporting ecosystem service. We provide a comprehensive case study on how seed-dispersed plants

  10. Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.

    Directory of Open Access Journals (Sweden)

    Jonas J Lembrechts

    Full Text Available Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment.

  11. Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.

    Science.gov (United States)

    Lembrechts, Jonas J; Milbau, Ann; Nijs, Ivan

    2014-01-01

    Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment.

  12. A global database of sap flow measurements (SAPFLUXNET) to link plant and ecosystem physiology

    Science.gov (United States)

    Poyatos, Rafael; Granda, Víctor; Flo, Víctor; Molowny-Horas, Roberto; Mencuccini, Maurizio; Oren, Ram; Katul, Gabriel; Mahecha, Miguel; Steppe, Kathy; Martínez-Vilalta, Jordi

    2017-04-01

    Regional and global networks of ecosystem CO2 and water flux monitoring have dramatically increased our understanding of ecosystem functioning in the last 20 years. More recently, analyses of ecosystem-level fluxes have successfully incorporated data streams at coarser (remote sensing) and finer (plant traits) organisational scales. However, there are few data sources that capture the diel to seasonal dynamics of whole-plant physiology and that can provide a link between organism- and ecosystem-level function. Sap flow measured in plant stems reveals the temporal patterns in plant water transport, as mediated by stomatal regulation and hydraulic architecture. The widespread use of thermometric methods of sap flow measurement since the 1990s has resulted in numerous data sets for hundreds of species and sites worldwide, but these data have remained fragmentary and generally unavailable for syntheses of regional to global scope. We are compiling the first global database of sub-daily sap flow measurements in individual plants (SAPFLUXNET), aimed at unravelling the environmental and biotic drivers of plant transpiration regulation globally. I will present the SAPFLUXNET data infrastructure and workflow, which is built upon flexible, open-source computing tools within the R environment (dedicated R packages and classes, interactive documents and apps with Rmarkdown and Shiny). Data collection started in mid-2016, we have already incorporated > 50 datasets representing > 40 species and > 350 individual plants, globally distributed, and the number of contributed data sets is increasing rapidly. I will provide a general overview of the distribution of available data sets according to climate, measurement method, species, functional groups and plant size attributes. In parallel to the sap flow data compilation, we have also collated published results from calibrations of sap flow methods, to provide a first quantification on the variability associated with different sap

  13. Automated plant, production management system

    Science.gov (United States)

    Aksenova, V. I.; Belov, V. I.

    1984-12-01

    The development of a complex of tasks for the operational management of production (OUP) within the framework of an automated system for production management (ASUP) shows that it is impossible to have effective computations without reliable initial information. The influence of many factors involving the production and economic activity of the entire enterprise upon the plan and course of production are considered. It is suggested that an adequate model should be available which covers all levels of the hierarchical system: workplace, section (bridgade), shop, enterprise, and the model should be incorporated into the technological sequence of performance and there should be provisions for an adequate man machine system.

  14. AVLIS Production Plant Project Management Plan

    International Nuclear Information System (INIS)

    1984-01-01

    The AVLIS Production Plant is designated as a Major System Acquisition (in accordance with DOE Order 4240.IC) to deploy Atomic Vapor Laser Isotope Separation (AVLIS) technology at the Oak Ridge, Tennessee site, in support of the US Uranium Enrichment Program. The AVLIS Production Plant Project will deploy AVLIS technology by performing the design, construction, and startup of a production plant that will meet capacity production requirements of the Uranium Enrichment Program. The AVLIS Production Plant Project Management Plan has been developed to outline plans, baselines, and control systems to be employed in managing the AVLIS Production Plant Project and to define the roles and responsibilities of project participants. Participants will develop and maintain detailed procedures for implementing the management and control systems in agreement with this plan. This baseline document defines the system that measures work performed and costs incurred. This plan was developed by the AVLIS Production Plant Project staff of Martin Marietta Energy Systems, Inc. and Lawrence Livermore National Laboratory in accordance with applicable DOE directives, orders and notices. 38 figures, 19 tables

  15. Natural products – learning chemistry from plants

    NARCIS (Netherlands)

    Staniek, A.; Bouwmeester, H.J.; Fraser, P.D.; Kayser, O.; Martens, S.; Tissier, A.; Krol, van der A.R.; Wessjohann, L.; Warzecha, H.

    2014-01-01

    Plant natural products (PNPs) are unique in that they represent a vast array of different structural features, ranging from relatively simple molecules to very complex ones. Given the fact that many plant secondary metabolites exhibit profound biological activity, they are frequently used as

  16. AVLIS production plant waste management plan

    International Nuclear Information System (INIS)

    1984-01-01

    Following the executive summary, this document contains the following: (1) waste management facilities design objectives; (2) AVLIS production plant wastes; (3) waste management design criteria; (4) waste management plan description; and (5) waste management plan implementation. 17 figures, 18 tables

  17. Modifying plants for biofuel and biomaterial production.

    Science.gov (United States)

    Furtado, Agnelo; Lupoi, Jason S; Hoang, Nam V; Healey, Adam; Singh, Seema; Simmons, Blake A; Henry, Robert J

    2014-12-01

    The productivity of plants as biofuel or biomaterial crops is established by both the yield of plant biomass per unit area of land and the efficiency of conversion of the biomass to biofuel. Higher yielding biofuel crops with increased conversion efficiencies allow production on a smaller land footprint minimizing competition with agriculture for food production and biodiversity conservation. Plants have traditionally been domesticated for food, fibre and feed applications. However, utilization for biofuels may require the breeding of novel phenotypes, or new species entirely. Genomics approaches support genetic selection strategies to deliver significant genetic improvement of plants as sources of biomass for biofuel manufacture. Genetic modification of plants provides a further range of options for improving the composition of biomass and for plant modifications to assist the fabrication of biofuels. The relative carbohydrate and lignin content influences the deconstruction of plant cell walls to biofuels. Key options for facilitating the deconstruction leading to higher monomeric sugar release from plants include increasing cellulose content, reducing cellulose crystallinity, and/or altering the amount or composition of noncellulosic polysaccharides or lignin. Modification of chemical linkages within and between these biomass components may improve the ease of deconstruction. Expression of enzymes in the plant may provide a cost-effective option for biochemical conversion to biofuel. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  18. Fungal Production and Manipulation of Plant Hormones.

    Science.gov (United States)

    Fonseca, Sandra; Radhakrishnan, Dhanya; Prasad, Kalika; Chini, Andrea

    2018-01-01

    Living organisms are part of a highly interconnected web of interactions, characterised by species nurturing, competing, parasitizing and preying on one another. Plants have evolved cooperative as well as defensive strategies to interact with neighbour organisms. Among these, the plant-fungus associations are very diverse, ranging from pathogenic to mutualistic. Our current knowledge of plant-fungus interactions suggests a sophisticated coevolution to ensure dynamic plant responses to evolving fungal mutualistic/pathogenic strategies. The plant-fungus communication relies on a rich chemical language. To manipulate the plant defence mechanisms, fungi produce and secrete several classes of biomolecules, whose modeof- action is largely unknown. Upon perception of the fungi, plants produce phytohormones and a battery of secondary metabolites that serve as defence mechanism against invaders or to promote mutualistic associations. These mutualistic chemical signals can be co-opted by pathogenic fungi for their own benefit. Among the plant molecules regulating plant-fungus interaction, phytohormones play a critical role since they modulate various aspects of plant development, defences and stress responses. Intriguingly, fungi can also produce phytohormones, although the actual role of fungalproduced phytohormones in plant-fungus interactions is poorly understood. Here, we discuss the recent advances in fungal production of phytohormone, their putative role as endogenous fungal signals and how fungi manipulate plant hormone balance to their benefits. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Acclimation of methane production weakens ecosystem response to climate warming in a northern peatland

    Science.gov (United States)

    MA, S.; Huang, Y.; Jiang, J.; Ricciuto, D. M.; Hanson, P. J.; Luo, Y.

    2017-12-01

    Warming-induced increases in greenhouse gases from terrestrial ecosystems represent a positive feedback to twenty-first-century climate warming, but the magnitude of this stimulatory effect remains uncertain. Acclimation of soil respiration and photosynthesis have been found to slow down the feedback due to the substrate limitation and thermal adaptation. However, acclimation of ecosystem methane emission to climate warming has not been well illustrated, despite that methane is directly responsible for approximately 20% of global warming since pre-industrial time. In this study, we used the data-model fusion approach to explore the potential acclimation of methane emission to climate warming. We assimilated CH4 static chamber flux data at the Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) experimental site into the ecosystem model, TECO_SPRUCE. The SPRUCE project has been conducted to study the responses of northern peatland to climate warming (+0, +2.25, +4.5, +6.75, +9 °C) and elevated atmospheric CO2 concentration (+0 and +500 ppm). The warming treatments were initiated from June 2014. We estimated parameter values using environmental and flux data in those five warming treatment levels from 2014 to 2016 for the acclimation study. The key parameters that were estimated for methane emissions are the potential ratio of CO2 converted to CH4 (r_me), Q10 for CH4 production (Q10_pro), maximum oxidation rate (Omax) and the factor of transport ability at plant community level (Tveg). Among them, r_me and Q10_pro were well constrained in each treatment plot. Q10 decreased from 3.33 (control) to 1.22 (+9˚C treatment) and r_me decreased from 0.675 (control) to 0.505 (+9˚C treatment). The acclimation will dampen the warming effect on methane production and emission. Current ecosystem models assumed constant Q10 for CH4 production and CH4/CO2 conversion ratio in the future warmed climate. The assumption is likely to overestimate the methane

  20. Can biomass responses to warming at plant to ecosystem levels be predicted by leaf-level responses?

    Science.gov (United States)

    Xia, J.; Shao, J.; Zhou, X.; Yan, W.; Lu, M.

    2015-12-01

    Global warming has the profound impacts on terrestrial C processes from leaf to ecosystem scales, potentially feeding back to climate dynamics. Although numerous studies had investigated the effects of warming on C processes from leaf to plant and ecosystem levels, how leaf-level responses to warming scale up to biomass responses at plant, population, and community levels are largely unknown. In this study, we compiled a dataset from 468 papers at 300 experimental sites and synthesized the warming effects on leaf-level parameters, and plant, population and ecosystem biomass. Our results showed that responses of plant biomass to warming mainly resulted from the changed leaf area rather than the altered photosynthetic capacity. The response of ecosystem biomass to warming was weaker than those of leaf area and plant biomass. However, the scaling functions from responses of leaf area to plant biomass to warming were different in diverse forest types, but functions were similar in non-forested biomes. In addition, it is challenging to scale the biomass responses from plant up to ecosystem. These results indicated that leaf area might be the appropriate index for plant biomass response to warming, and the interspecific competition might hamper the scaling of the warming effects on plant and ecosystem levels, suggesting that the acclimation capacity of plant community should be incorporated into land surface models to improve the prediction of climate-C cycle feedback.

  1. 7 CFR 302.2 - Movement of plants and plant products.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Movement of plants and plant products. 302.2 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DISTRICT OF COLUMBIA; MOVEMENT OF PLANTS AND PLANT PRODUCTS § 302.2 Movement of plants and plant products. Inspection or documentation of the plant health status of...

  2. Simulating the indirect effects of power plant entrainment losses on an estuarine ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Summers, J.K. (Versar, Inc., Columbia, MD (USA))

    1989-12-01

    Entrainment caused by the operation of the Chalk Point Steam Electric Station has been shown to be a major source of mortality to the early life stages of forage fish populations in the Patuxent River, MD, USA. While direct losses to these populations are important as a source of reduction for population abundance, these losses also represent decreases in estuarine forage supplies and potential reductions in the abundances of estuarine predators. A simple estuarine trophic dynamics model was constructed to determine the magnitude of the potential losses to major estuarine consumers in the Patuxent River ecosystem due to the power plant-related losses of forage fish. Simulations were completed using two sets of feeding assumptions: feeding proportional to forage abundance, and feeding based on dietary preferences. The model demonstrates that striped bass, bluefish, and weakfish could experience significant losses (> 25%) to overall population production levels if they prefer to prey upon bay anchovy and silversides and entrainment losses to these forage populations is {>=} 70% of juvenile recruitment. The model also shows that indirect predator losses would be expected to be low (> 5%) if the majority of their diets consisted of forage other than bay anchovy and silversides. 2 figs., 31 refs., 4 tabs.

  3. Biomass production efficiency controlled by management in temperate and boreal ecosystems

    NARCIS (Netherlands)

    Campioli, M.; Vicca, S.; Luyssaert, S.; Bilcke, J.; Ceschia, E.; Chapin, F.S. III; Ciais, P.; Fernández-Martínez, M.; Malhi, Y.; Obersteiner, M.; Olefeldt, D.; Papale, D.; Piao, S.L.; Peñuelas, J.; Sullivan, P. F.; Wang, X.; Zenone, T.; Janssens, I.A.

    2015-01-01

    Plants acquire carbon through photosynthesis to sustain biomass production, autotrophic respiration and production of non-structural compounds for multiple purposes. The fraction of photosynthetic production used for biomass production, the biomass production efficiency, is a key determinant of the

  4. Experimental effects of herbivore density on above-ground plant biomass in an alpine grassland ecosystem

    OpenAIRE

    Austrheim, Gunnar; Speed, James David Mervyn; Martinsen, Vegard; Mulder, Jan; Mysterud, Atle

    2014-01-01

    Herbivores may increase or decrease aboveground plant productivity depending on factors such as herbivore density and habitat productivity. The grazing optimization hypothesis predicts a peak in plant production at intermediate herbivore densities, but has rarely been tested experimentally in an alpine field setting. In an experimental design with three densities of sheep (high, low, and no sheep), we harvested aboveground plant biomass in alpine grasslands prior to treatment and after five y...

  5. The influence of subsurface porosity and bedrock composition on ecosystem productivity and drought resilience in the Sierra Nevada Batholith, California

    Science.gov (United States)

    Riebe, C. S.; Callahan, R. P.; Goulden, M.; Pasquet, S.; Flinchum, B. A.; Taylor, N. J.; Holbrook, W. S.

    2017-12-01

    The availability of water and nutrients in soil and weathered rock influences the distribution of Earth's terrestrial life and regulates ecosystem vulnerability to land use and climate change. We explored these relationships by combining geochemical and geophysical measurements at three mid-elevation sites in the Sierra Nevada, California. Forest cover correlates strongly with bedrock composition across the sites, implying strong lithologic control on the ecosystem. We evaluated two hypotheses about bedrock-ecosystem connections: 1) that bedrock composition influences vegetation by moderating plant-essential nutrient supply; and 2) that bedrock composition influences the degree of subsurface weathering, which influences vegetation by controlling subsurface water-storage capacity. To quantify subsurface water-holding capacity, we used seismic refraction surveys to infer gradients in P and S-wave velocity structure, which reveal variations in porosity when coupled together in a Hertz-Mindlin rock-physics model. We combined the geophysical data on porosity with bedrock bulk geochemistry measured in previous work to evaluate the influence of water-holding capacity and nutrient supply on ecosystem productivity, which we quantified using remote sensing. Our results show that more than 80% of the variance in ecosystem productivity can be explained by differences in bedrock phosphorus concentration and subsurface porosity, with phosphorus content being the dominant explanatory variable. This suggests that bedrock composition exerts a strong bottom-up control on ecosystem productivity through its influence on nutrient supply and weathering susceptibility, which in turn influences porosity. We show that vegetation vulnerability to drought stress and mortality can be explained in part by variations in subsurface water-holding capacity and rock-derived nutrient supply.

  6. Assessing impacts of intensified biomass production and biodiversity protection on ecosystem services provided by European forests

    NARCIS (Netherlands)

    Verkerk, P.J.; Mavsar, R.; Giergiczny, M.; Lindner, M.; Edwards, D.; Schelhaas, M.J.

    2014-01-01

    To develop viable strategies for intensifying the use of forest biomass and for increasing forest protection, impacts on ecosystem services need to be assessed. We investigated the biophysical and economic impacts of increased forest biomass production and biodiversity protection on forest ecosystem

  7. Ecosystem services: foundations, opportunities, and challenges for the forest products sector

    Science.gov (United States)

    Trista M. Patterson; Dana L. Coelho

    2009-01-01

    The ecosystem service concept has been proposed as a meaningful framework for natural resource management. In theory, it holds concomitant benefit and consequence for the forest product sector. However, numerous barriers impede practitioners from developing concrete and enduring responses to emerging ecosystem service markets, policies, and initiatives. Principal among...

  8. Probabilistic production simulation including CHP plants

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, H.V.; Palsson, H.; Ravn, H.F.

    1997-04-01

    A probabilistic production simulation method is presented for an energy system containing combined heat and power plants. The method permits incorporation of stochastic failures (forced outages) of the plants and is well suited for analysis of the dimensioning of the system, that is, for finding the appropriate types and capacities of production plants in relation to expansion planning. The method is in the tradition of similar approaches for the analysis of power systems, based on the load duration curve. The present method extends on this by considering a two-dimensional load duration curve where the two dimensions represent heat and power. The method permits the analysis of a combined heat and power system which includes all the basic relevant types of plants, viz., condensing plants, back pressure plants, extraction plants and heat plants. The focus of the method is on the situation where the heat side has priority. This implies that on the power side there may be imbalances between demand and production. The method permits quantification of the expected power overflow, the expected unserviced power demand, and the expected unserviced heat demand. It is shown that a discretization method as well as double Fourier series may be applied in algorithms based on the method. (au) 1 tab., 28 ills., 21 refs.

  9. Valuing tradeoffs between agricultural production and ecosystem services in the Heihe River Basin

    Science.gov (United States)

    Li, Z.; Deng, X.; Wu, F.

    2017-12-01

    Ecosystem services are faced with multiple stress from complex driving factors, such as climate change and human interventions. The Heihe River Basin (HRB), as the second largest inland river basin in China, is a typical semi-arid and arid region with fragile and sensitive ecological environment. For the past decades, agricultural production activities in the basin has affected ecosystem services in different degrees, leading to complex relations among "water-land-climate-ecology-human", in which hydrological process and water resource management is the key. In this context, managing trade-offs among water uses in the river basin to sustain multiple ecosystem services is crucial for healthy ecosystem and sustainable socioeconomic development. In this study, we analyze the trade-offs between different water uses in agricultural production and key ecosystem services in the HRB by applying production frontier analysis, with the aim to explore the potential for managing them. This method traces out joint production frontiers showing the combinations of ecosystem services and agricultural production that can be generated in a given area, and it deals with the economic problem of the allocation of scarce water resources under presumed objective, which aims to highlight synergies and reduce trade-offs between alternative water uses. Thus, management schemes that targets to both sustain agricultural production and increase the provision of key ecosystem services have to consider not only the technological or biological nature of interrelationships, but also the economic interdependencies among them.

  10. Do ecohydrology and community dynamics feed back to banded-ecosystem structure and productivity?

    Science.gov (United States)

    Callegaro, Chiara; Ursino, Nadia

    2016-04-01

    Mixed communities including grass, shrubs and trees are often reported to populate self-organized vegetation patterns. Patterns of survey data suggest that species diversity and complementarity strengthen the dynamics of banded environments. Resource scarcity and local facilitation trigger self organization, whereas coexistence of multiple species in vegetated self-organizing patches, implying competition for water and nutrients and favorable reproduction sites, is made possible by differing adaptation strategies. Mixed community spatial self-organization has so far received relatively little attention, compared with local net facilitation of isolated species. We assumed that soil moisture availability is a proxy for the environmental niche of plant species according to Ursino and Callegaro (2016). Our modelling effort was focused on niche differentiation of coexisting species within a tiger bush type ecosystem. By minimal numerical modelling and stability analysis we try to answer a few open scientific questions: Is there an adaptation strategy that increases biodiversity and ecosystem functioning? Does specific adaptation to environmental niches influence the structure of self-organizing vegetation pattern? What specific niche distribution along the environmental gradient gives the highest global productivity?

  11. Invasion of a Legume Ecosystem Engineer in a Cold Biome Alters Plant Biodiversity

    Directory of Open Access Journals (Sweden)

    Vanessa M. S. Vetter

    2018-06-01

    Full Text Available Plant ecosystem engineers are widely used to combat land degradation. However, the ability of those plants to modulate limiting abiotic and biotic resources of other species can cause damage to ecosystems in which they become invasive. Here, we use Lupinus nootkatensis as example to estimate and project the hazardous potential of nitrogen fixing herbaceous plants in a sub-polar oceanic climate. L. nootkatensis was introduced to Iceland in the 1940s to address erosion problems and foster reforestation, but subsequently became a high-latitude invader. In a local field survey, we quantified the impact of L. nootkatensis invasion at three different cover levels (0, 10–50, and 51–100% upon native plant diversity, richness, and community composition of heath-, wood-, and grasslands using a pairwise comparison design and comparisons of means. Afterward, we scaled impacts up to the ecosystem and landscape level by relating occurrences of L. nootkatensis to environmental and human-mediated variables across Iceland using a species distribution model. Plant diversity was significantly deteriorated under high lupine cover levels of the heath- and woodland, but not in the grassland. Plant species richness of the most diverse habitat, the heathland, linearly decreased with lupine cover level. The abundance of small rosettes, cushion plants, orchids, and small woody long-lived plants of the heath declined with invader presence, while the abundance of late successional species and widespread nitrophilous ruderals in wood- and grasslands increased. Distribution modeling revealed 13.3% of Iceland’s land surface area to be suitable lupine habitat. Until 2061–2080, this area will more than double and expand significantly into the Central Highlands due to human mediation and increasingly favorable climatic conditions. Species-rich habitats showed a loss of plant species diversity and richness as well as a change in community composition even in low lupine

  12. Estimating Gross Primary Productivity of a tropical forest ecosystem ...

    Indian Academy of Sciences (India)

    37

    forest ecosystem over north-east India using LAI and meteorological ... water and Greenhouse Gas (GHG) fluxes between the biosphere and the at- mosphere ..... calculated from these by internal algorithms of LAI-2200 and stored in its in-built ..... 2007). As a result of these enhanced CO2 emission could be observed from.

  13. Modelling the dynamic interactions between food production and ecosystem services

    NARCIS (Netherlands)

    Duku, C.

    2017-01-01

    Given the high levels of food insecurity and the loss of vital ecosystem services associated with deforestation, countries in sub-Saharan Africa (SSA) face a major dilemma. How can they produce enough food in a changing climate to feed an increasing population while protecting natural forests and

  14. Plant functional traits in relation to fire in crown-fire ecosystems

    Science.gov (United States)

    Pausas, Juli G.; Bradstock, Ross A.; Keith, David A.; Keeley, Jon E.

    2004-01-01

    Disturbance is a dominant factor in many ecosystems, and the disturbance regime is likely to change over the next decades in response to land-use changes and global warming. We assume that predictions of vegetation dynamics can be made on the basis of a set of life-history traits that characterize the response of a species to disturbance. For crown-fire ecosystems, the main plant traits related to postfire persistence are the ability to resprout (persistence of individuals) and the ability to retain a persistent seed bank (persistence of populations). In this context, we asked (1) to what extent do different life-history traits co-occur with the ability to resprout and/or the ability to retain a persistent seed bank among differing ecosystems and (2) to what extent do combinations of fire-related traits (fire syndromes) change in a fire regime gradient? We explored these questions by reviewing the literature and analyzing databases compiled from different crown-fire ecosystems (mainly eastern Australia, California, and the Mediterranean basin). The review suggests that the pattern of correlation between the two basic postfire persistent traits and other plant traits varies between continents and ecosystems. From these results we predict, for instance, that not all resprouters respond in a similar way everywhere because the associated plant traits of resprouter species vary in different places. Thus, attempts to generalize predictions on the basis of the resprouting capacity may have limited power at a global scale. An example is presented for Australian heathlands. Considering the combination of persistence at individual (resprouting) and at population (seed bank) level, the predictive power at local scale was significantly increased.

  15. Predicting Plant-Accessible Water in the Critical Zone: Mountain Ecosystems in a Mediterranean Climate

    Science.gov (United States)

    Klos, P. Z.; Goulden, M.; Riebe, C. S.; Tague, C.; O'Geen, A. T.; Flinchum, B. A.; Safeeq, M.; Conklin, M. H.; Hart, S. C.; Asefaw Berhe, A.; Hartsough, P. C.; Holbrook, S.; Bales, R. C.

    2017-12-01

    Enhanced understanding of subsurface water storage, and the below-ground architecture and processes that create it, will advance our ability to predict how the impacts of climate change - including drought, forest mortality, wildland fire, and strained water security - will take form in the decades to come. Previous research has examined the importance of plant-accessible water in soil, but in upland landscapes within Mediterranean climates the soil is often only the upper extent of subsurface water storage. We draw insights from both this previous research and a case study of the Southern Sierra Critical Zone Observatory to: define attributes of subsurface storage, review observed patterns in its distribution, highlight nested methods for its estimation across scales, and showcase the fundamental processes controlling its formation. We observe that forest ecosystems at our sites subsist on lasting plant-accessible stores of subsurface water during the summer dry period and during multi-year droughts. This indicates that trees in these forest ecosystems are rooted deeply in the weathered, highly porous saprolite, which reaches up to 10-20 m beneath the surface. This confirms the importance of large volumes of subsurface water in supporting ecosystem resistance to climate and landscape change across a range of spatiotemporal scales. This research enhances the ability to predict the extent of deep subsurface storage across landscapes; aiding in the advancement of both critical zone science and the management of natural resources emanating from similar mountain ecosystems worldwide.

  16. Potential ecosystem service delivery by endemic plants in New Zealand vineyards: successes and prospects.

    Science.gov (United States)

    Shields, Morgan W; Tompkins, Jean-Marie; Saville, David J; Meurk, Colin D; Wratten, Stephen

    2016-01-01

    Vineyards worldwide occupy over 7 million hectares and are typically virtual monocultures, with high and costly inputs of water and agro-chemicals. Understanding and enhancing ecosystem services can reduce inputs and their costs and help satisfy market demands for evidence of more sustainable practices. In this New Zealand work, low-growing, endemic plant species were evaluated for their potential benefits as Service Providing Units (SPUs) or Ecosystem Service Providers (ESPs). The services provided were weed suppression, conservation of beneficial invertebrates, soil moisture retention and microbial activity. The potential Ecosystem Dis-services (EDS) from the selected plant species by hosting the larvae of a key vine moth pest, the light-brown apple moth (Epiphyas postvittana), was also quantified. Questionnaires were used to evaluate winegrowers' perceptions of the value of and problems associated with such endemic plant species in their vineyards. Growth and survival rates of the 14 plant species, in eight families, were evaluated, with Leptinella dioica (Asteraceae) and Acaena inermis 'purpurea' (Rosaceae) having the highest growth rates in terms of area covered and the highest survival rate after 12 months. All 14 plant species suppressed weeds, with Leptinella squalida, Geranium sessiliforum (Geraniaceae), Hebe chathamica (Plantaginaceae), Scleranthus uniflorus (Caryophyllaceae) and L. dioica, each reducing weed cover by >95%. Plant species also differed in the diversity of arthropods that they supported, with the Shannon Wiener diversity index (H') for these taxa ranging from 0 to 1.3. G. sessiliforum and Muehlenbeckia axillaris (Polygonaceae) had the highest invertebrate diversity. Density of spiders was correlated with arthropod diversity and G. sessiliflorum and H. chathamica had the highest densities of these arthropods. Several plant species associated with higher soil moisture content than in control plots. The best performing species in this context

  17. Potential ecosystem service delivery by endemic plants in New Zealand vineyards: successes and prospects

    Directory of Open Access Journals (Sweden)

    Morgan W. Shields

    2016-06-01

    Full Text Available Vineyards worldwide occupy over 7 million hectares and are typically virtual monocultures, with high and costly inputs of water and agro-chemicals. Understanding and enhancing ecosystem services can reduce inputs and their costs and help satisfy market demands for evidence of more sustainable practices. In this New Zealand work, low-growing, endemic plant species were evaluated for their potential benefits as Service Providing Units (SPUs or Ecosystem Service Providers (ESPs. The services provided were weed suppression, conservation of beneficial invertebrates, soil moisture retention and microbial activity. The potential Ecosystem Dis-services (EDS from the selected plant species by hosting the larvae of a key vine moth pest, the light-brown apple moth (Epiphyas postvittana, was also quantified. Questionnaires were used to evaluate winegrowers’ perceptions of the value of and problems associated with such endemic plant species in their vineyards. Growth and survival rates of the 14 plant species, in eight families, were evaluated, with Leptinella dioica (Asteraceae and Acaena inermis ‘purpurea’ (Rosaceae having the highest growth rates in terms of area covered and the highest survival rate after 12 months. All 14 plant species suppressed weeds, with Leptinella squalida, Geranium sessiliforum (Geraniaceae, Hebe chathamica (Plantaginaceae, Scleranthus uniflorus (Caryophyllaceae and L. dioica, each reducing weed cover by >95%. Plant species also differed in the diversity of arthropods that they supported, with the Shannon Wiener diversity index (H′ for these taxa ranging from 0 to 1.3. G. sessiliforum and Muehlenbeckia axillaris (Polygonaceae had the highest invertebrate diversity. Density of spiders was correlated with arthropod diversity and G. sessiliflorum and H. chathamica had the highest densities of these arthropods. Several plant species associated with higher soil moisture content than in control plots. The best performing species

  18. Radioecological monitoring of the Tom' river ecosystem within zone of nuclear fuel cycle plants influence

    International Nuclear Information System (INIS)

    Leonova, G.A.; Bobrov, V.A.; Malikov, Yu.I.; Mel'gunov, M.S.; Makarova, I.V.; Toropov, A.V.

    2005-01-01

    According to the results of 2000-2002 expeditions the estimation of radioactive contamination scales in water ecosystems within zone of Siberian Chemical Industrial Complex (SCC) influence was performed. The accumulation levels of short-lived artificial radionuclides in biota components of SCC technological channel (Romashka river), and spatial radionuclide distribution in biota of ecosystem of the Tom' and Ob' rivers at different distances from the local source have been determined using biochemical indication method. The most frequently occurring species of plants, filamentous green algae and fish were selected as indicator bioobjects for the monitoring. In spectrum of radioisotopes revealed in water plants, fish and water of the Romashka river there were determined twelve short-living isotopes that denoted continuing river burial. (author)

  19. Evolving software products, the design of a water-related modeling software ecosystem

    DEFF Research Database (Denmark)

    Manikas, Konstantinos

    2017-01-01

    more than 50 years ago. However, a radical change of software products to evolve both in the software engineering as much as the organizational and business aspects in a disruptive manner are rather rare. In this paper, we report on the transformation of one of the market leader product series in water......-related calculation and modeling from a traditional business-as-usual series of products to an evolutionary software ecosystem. We do so by relying on existing concepts on software ecosystem analysis to analyze the future ecosystem. We report and elaborate on the main focus points necessary for this transition. We...... argue for the generalization of our focus points to the transition from traditional business-as-usual software products to software ecosystems....

  20. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Directory of Open Access Journals (Sweden)

    Jeremy Lundholm

    Full Text Available Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that

  1. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Science.gov (United States)

    Lundholm, Jeremy; Heim, Amy; Tran, Stephanie; Smith, Tyler

    2014-01-01

    Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth) to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies) for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that favor less

  2. Forest and Chernobyl: forest ecosystems after the Chernobyl nuclear power plant accident: 1986-1994

    International Nuclear Information System (INIS)

    Ipatyev, V.; Bulavik, I.; Baginsky, V.; Goncharenko, G.; Dvornik, A.

    1999-01-01

    This paper reports basic features of radionuclide migration and the prediction of the radionuclide redistribution and accumulation by forest phytocoenoses after the Chernobyl Nuclear Power Plant (CNPP) accident. The current ecological condition of forest ecosystems is evaluated and scientific aspects of forest management in the conditions of the large-scale radioactive contamination are discussed. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Balance matters : N:P stoichiometry and plant diversity in grassland ecosystems

    NARCIS (Netherlands)

    Fujita, Y.

    2010-01-01

    Eutrophication of Nitrogen (N) and Phosphorus (P) is threatening the functioning and biodiversity of grassland ecosystems. A well known effect of eutrophication on grasslands is an increase of above-ground productivity, which intensifies light competition and allows only a few competitive species to

  4. Vegetation component of geothermal EIS studies: Introduced plants, ecosystem stability, and geothermal development

    International Nuclear Information System (INIS)

    1994-10-01

    This paper contributes new information about the impacts from introduced plant invasions on the native Hawaiian vegetation as consequences of land disturbance and geothermal development activities. In this regard, most geothermal development is expected to act as another recurring source of physical disturbance which favors the spread and maintenance of introduced organisms throughout the region. Where geothermal exploration and development activities extend beyond existing agricultural and residential development, they will become the initial or sole source of disturbance to the naturalized vegetation of the area. Kilauea has a unique ecosystem adapted to the dynamics of a volcanically active landscape. The characteristics of this ecosystem need to be realized in order to understand the major threats to the ecosystem and to evaluate the effects of and mitigation for geothermal development in Puna. The native Puna vegetation is well adapted to disturbances associated with volcanic eruption, but it is ill-adapted to compete with alien plant species in secondary disturbances produced by human activities. Introduced plant and animal species have become a major threat to the continued presence of the native biota in the Puna region of reference

  5. Vegetation component of geothermal EIS studies: Introduced plants, ecosystem stability, and geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-01

    This paper contributes new information about the impacts from introduced plant invasions on the native Hawaiian vegetation as consequences of land disturbance and geothermal development activities. In this regard, most geothermal development is expected to act as another recurring source of physical disturbance which favors the spread and maintenance of introduced organisms throughout the region. Where geothermal exploration and development activities extend beyond existing agricultural and residential development, they will become the initial or sole source of disturbance to the naturalized vegetation of the area. Kilauea has a unique ecosystem adapted to the dynamics of a volcanically active landscape. The characteristics of this ecosystem need to be realized in order to understand the major threats to the ecosystem and to evaluate the effects of and mitigation for geothermal development in Puna. The native Puna vegetation is well adapted to disturbances associated with volcanic eruption, but it is ill-adapted to compete with alien plant species in secondary disturbances produced by human activities. Introduced plant and animal species have become a major threat to the continued presence of the native biota in the Puna region of reference.

  6. Plant Products for Innovative Biomaterials in Dentistry

    Directory of Open Access Journals (Sweden)

    Elena M. Varoni

    2012-07-01

    Full Text Available Dental biomaterials and natural products represent two of the main growing research fields, revealing plant-derived compounds may play a role not only as nutraceuticals in affecting oral health, but also in improving physico-chemical properties of biomaterials used in dentistry. Therefore, our aim was to collect all available data concerning the utilization of plant polysaccharides, proteins and extracts rich in bioactive phytochemicals in enhancing performance of dental biomaterials. Although compelling evidences are suggestive of a great potential of plant products in promoting material-tissue/cell interface, to date, only few authors have investigated their use in development of innovative dental biomaterials. A small number of studies have reported plant extract-based titanium implant coatings and periodontal regenerative materials. To the best of our knowledge, this review is the first to deal with this topic, highlighting a general lack of research findings in an interesting field which still needs to be investigated.

  7. Top predators, mesopredators and their prey: interference ecosystems along bioclimatic productivity gradients.

    Science.gov (United States)

    Elmhagen, B; Ludwig, G; Rushton, S P; Helle, P; Lindén, H

    2010-07-01

    1. The Mesopredator Release Hypothesis (MRH) suggests that top predator suppression of mesopredators is a key ecosystem function with cascading impacts on herbivore prey, but it remains to be shown that this top-down cascade impacts the large-scale structure of ecosystems. 2. The Exploitation Ecosystems Hypothesis (EEH) predicts that regional ecosystem structures are determined by top-down exploitation and bottom-up productivity. In contrast to MRH, EEH assumes that interference among predators has a negligible impact on the structure of ecosystems with three trophic levels. 3. We use the recolonization of a top predator in a three-level boreal ecosystem as a natural experiment to test if large-scale biomass distributions and population trends support MRH. Inspired by EEH, we also test if top-down interference and bottom-up productivity impact regional ecosystem structures. 4. We use data from the Finnish Wildlife Triangle Scheme which has monitored top predator (lynx, Lynx lynx), mesopredator (red fox, Vulpes vulpes) and prey (mountain hare, Lepus timidus) abundance for 17 years in a 200 000 km(2) study area which covers a distinct productivity gradient. 5. Fox biomass was lower than expected from productivity where lynx biomass was high, whilst hare biomass was lower than expected from productivity where fox biomass was high. Hence, where interference controlled fox abundance, lynx had an indirect positive impact on hare abundance as predicted by MRH. The rates of change indicated that lynx expansion gradually suppressed fox biomass. 6. Lynx status caused shifts between ecosystem structures. In the 'interference ecosystem', lynx and hare biomass increased with productivity whilst fox biomass did not. In the 'mesopredator release ecosystem', fox biomass increased with productivity but hare biomass did not. Thus, biomass controlled top-down did not respond to changes in productivity. This fulfils a critical prediction of EEH. 7. We conclude that the cascade

  8. Farming for Ecosystem Services: An Ecological Approach to Production Agriculture

    Science.gov (United States)

    Philip Robertson, G.; Gross, Katherine L.; Hamilton, Stephen K.; Landis, Douglas A.; Schmidt, Thomas M.; Snapp, Sieglinde S.; Swinton, Scott M.

    2014-01-01

    A balanced assessment of ecosystem services provided by agriculture requires a systems-level socioecological understanding of related management practices at local to landscape scales. The results from 25 years of observation and experimentation at the Kellogg Biological Station long-term ecological research site reveal services that could be provided by intensive row-crop ecosystems. In addition to high yields, farms could be readily managed to contribute clean water, biocontrol and other biodiversity benefits, climate stabilization, and long-term soil fertility, thereby helping meet society's need for agriculture that is economically and environmentally sustainable. Midwest farmers—especially those with large farms—appear willing to adopt practices that deliver these services in exchange for payments scaled to management complexity and farmstead benefit. Surveyed citizens appear willing to pay farmers for the delivery of specific services, such as cleaner lakes. A new farming for services paradigm in US agriculture seems feasible and could be environmentally significant. PMID:26955069

  9. Farming for Ecosystem Services: An Ecological Approach to Production Agriculture.

    Science.gov (United States)

    Philip Robertson, G; Gross, Katherine L; Hamilton, Stephen K; Landis, Douglas A; Schmidt, Thomas M; Snapp, Sieglinde S; Swinton, Scott M

    2014-05-01

    A balanced assessment of ecosystem services provided by agriculture requires a systems-level socioecological understanding of related management practices at local to landscape scales. The results from 25 years of observation and experimentation at the Kellogg Biological Station long-term ecological research site reveal services that could be provided by intensive row-crop ecosystems. In addition to high yields, farms could be readily managed to contribute clean water, biocontrol and other biodiversity benefits, climate stabilization, and long-term soil fertility, thereby helping meet society's need for agriculture that is economically and environmentally sustainable. Midwest farmers-especially those with large farms-appear willing to adopt practices that deliver these services in exchange for payments scaled to management complexity and farmstead benefit. Surveyed citizens appear willing to pay farmers for the delivery of specific services, such as cleaner lakes. A new farming for services paradigm in US agriculture seems feasible and could be environmentally significant.

  10. Ecosystem productivity is associated with bacterial phylogenetic distance in surface marine waters.

    Science.gov (United States)

    Galand, Pierre E; Salter, Ian; Kalenitchenko, Dimitri

    2015-12-01

    Understanding the link between community diversity and ecosystem function is a fundamental aspect of ecology. Systematic losses in biodiversity are widely acknowledged but the impact this may exert on ecosystem functioning remains ambiguous. There is growing evidence of a positive relationship between species richness and ecosystem productivity for terrestrial macro-organisms, but similar links for marine micro-organisms, which help drive global climate, are unclear. Community manipulation experiments show both positive and negative relationships for microbes. These previous studies rely, however, on artificial communities and any links between the full diversity of active bacterial communities in the environment, their phylogenetic relatedness and ecosystem function remain hitherto unexplored. Here, we test the hypothesis that productivity is associated with diversity in the metabolically active fraction of microbial communities. We show in natural assemblages of active bacteria that communities containing more distantly related members were associated with higher bacterial production. The positive phylogenetic diversity-productivity relationship was independent of community diversity calculated as the Shannon index. From our long-term (7-year) survey of surface marine bacterial communities, we also found that similarly, productive communities had greater phylogenetic similarity to each other, further suggesting that the traits of active bacteria are an important predictor of ecosystem productivity. Our findings demonstrate that the evolutionary history of the active fraction of a microbial community is critical for understanding their role in ecosystem functioning. © 2015 John Wiley & Sons Ltd.

  11. Ecosystem carbon stock influenced by plantation practice: implications for planting forests as a measure of climate change mitigation.

    Directory of Open Access Journals (Sweden)

    Chengzhang Liao

    Full Text Available Uncertainties remain in the potential of forest plantations to sequestrate carbon (C. We synthesized 86 experimental studies with paired-site design, using a meta-analysis approach, to quantify the differences in ecosystem C pools between plantations and their corresponding adjacent primary and secondary forests (natural forests. Totaled ecosystem C stock in plant and soil pools was 284 Mg C ha(-1 in natural forests and decreased by 28% in plantations. In comparison with natural forests, plantations decreased aboveground net primary production, litterfall, and rate of soil respiration by 11, 34, and 32%, respectively. Fine root biomass, soil C concentration, and soil microbial C concentration decreased respectively by 66, 32, and 29% in plantations relative to natural forests. Soil available N, P and K concentrations were lower by 22, 20 and 26%, respectively, in plantations than in natural forests. The general pattern of decreased ecosystem C pools did not change between two different groups in relation to various factors: stand age ( or = 25 years, stand types (broadleaved vs. coniferous and deciduous vs. evergreen, tree species origin (native vs. exotic of plantations, land-use history (afforestation vs. reforestation and site preparation for plantations (unburnt vs. burnt, and study regions (tropic vs. temperate. The pattern also held true across geographic regions. Our findings argued against the replacement of natural forests by the plantations as a measure of climate change mitigation.

  12. Modification of plant-induced responses by an insect ecosystem engineer influences the colonization behaviour of subsequent shelter-users

    NARCIS (Netherlands)

    Uesugi, Akane; Morrell, Kimberly; Poelman, Erik H.; Raaijmakers, Ciska E.; Kessler, André

    2016-01-01

    * Herbivores that modify plant morphology, such as gall-forming insects, can disproportionately impact arthropod community on their host plants by providing novel habitats and shelters from biotic and abiotic stresses. These ecosystem engineers could also modify plant chemical properties, but how

  13. Post-mortem ecosystem engineering by oysters creates habitat for a rare marsh plant.

    Science.gov (United States)

    Guo, Hongyu; Pennings, Steven C

    2012-11-01

    Oysters are ecosystem engineers in marine ecosystems, but the functions of oyster shell deposits in intertidal salt marshes are not well understood. The annual plant Suaeda linearis is associated with oyster shell deposits in Georgia salt marshes. We hypothesized that oyster shell deposits promoted the distribution of Suaeda linearis by engineering soil conditions unfavorable to dominant salt marsh plants of the region (the shrub Borrichia frutescens, the rush Juncus roemerianus, and the grass Spartina alterniflora). We tested this hypothesis using common garden pot experiments and field transplant experiments. Suaeda linearis thrived in Borrichia frutescens stands in the absence of neighbors, but was suppressed by Borrichia frutescens in the with-neighbor treatment, suggesting that Suaeda linearis was excluded from Borrichia frutescens stands by interspecific competition. Suaeda linearis plants all died in Juncus roemerianus and Spartina alterniflora stands, regardless of neighbor treatments, indicating that Suaeda linearis is excluded from these habitats by physical stress (likely water-logging). In contrast, Borrichia frutescens, Juncus roemerianus, and Spartina alterniflora all performed poorly in Suaeda linearis stands regardless of neighbor treatments, probably due to physical stresses such as low soil water content and low organic matter content. Thus, oyster shell deposits play an important ecosystem engineering role in influencing salt marsh plant communities by providing a unique niche for Suaeda linearis, which otherwise would be rare or absent in salt marshes in the southeastern US. Since the success of Suaeda linearis is linked to the success of oysters, efforts to protect and restore oyster reefs may also benefit salt marsh plant communities.

  14. Flux of aquatic insect productivity to land: comparison of lentic and lotic ecosystems.

    Science.gov (United States)

    Gratton, Claudio; Vander Zanden, M Jake

    2009-10-01

    Recently, food web studies have started exploring how resources from one habitat or ecosystem influence trophic interactions in a recipient ecosystem. Benthic production in lakes and streams can be exported to terrestrial habitats via emerging aquatic insects and can therefore link aquatic and terrestrial ecosystems. In this study, we develop a general conceptual model that highlights zoobenthic production, insect emergence, and ecosystem geometry (driven principally by area-to-edge ratio) as important factors modulating the flux of aquatic production across the ecosystem boundary. Emerging insect flux, defined as total insect production emerging per meter of shoreline (g C x m(-1) x yr(-1)) is then distributed inland using decay functions and is used to estimate insect deposition rate to terrestrial habitats (g C x m(-2) x yr(-1)). Using empirical data from the literature, we simulate insect fluxes across the water-land ecosystem boundary to estimate the distribution of fluxes and insect deposition inland for lakes and streams. In general, zoobenthos in streams are more productive than in lakes (6.67 vs. 1.46 g C x m(-2) x yr(-1)) but have lower insect emergence to aquatic production ratios (0.19 vs. 0.30). However, as stream width is on average smaller than lake radius, this results in flux (F) estimates 2 1/2 times greater for lakes than for streams. Ultimately, insect deposition onto land (within 100 m of shore) adjacent to average-sized lakes (10-ha lakes, 0.021 g C x m(-2) x yr(-1)) is greater than for average-sized streams (4 m width, 0.002 g C x m(-2) x yr(-1)) used in our comparisons. For the average lake (both in size and productivity), insect deposition rate approaches estimates of terrestrial secondary production in low-productivity ecosystems (e.g., deserts and tundra, approximately 0.07 g C x m(-2) x yr(-1)). However, larger lakes (1300 ha) and streams (16 m) can have average insect deposition rates (approximately 0.01-2.4 g C x m(-2) x yr(-1

  15. Dual role of lignin in plant litter decomposition in terrestrial ecosystems.

    Science.gov (United States)

    Austin, Amy T; Ballaré, Carlos L

    2010-03-09

    Plant litter decomposition is a critical step in the formation of soil organic matter, the mineralization of organic nutrients, and the carbon balance in terrestrial ecosystems. Biotic decomposition in mesic ecosystems is generally negatively correlated with the concentration of lignin, a group of complex aromatic polymers present in plant cell walls that is recalcitrant to enzymatic degradation and serves as a structural barrier impeding microbial access to labile carbon compounds. Although photochemical mineralization of carbon has recently been shown to be important in semiarid ecosystems, litter chemistry controls on photodegradative losses are not understood. We evaluated the importance of litter chemistry on photodegradation of grass litter and cellulose substrates with varying levels of lignin [cellulose-lignin (CL) substrates] under field conditions. Using wavelength-specific light attenuation filters, we found that light-driven mass loss was promoted by both UV and visible radiation. The spectral dependence of photodegradation correlated with the absorption spectrum of lignin but not of cellulose. Field incubations demonstrated that increasing lignin concentration reduced biotic decomposition, as expected, but linearly increased photodegradation. In addition, lignin content in CL substrates consistently decreased in photodegradative incubations. We conclude that lignin has a dual role affecting litter decomposition, depending on the dominant driver (biotic or abiotic) controlling carbon turnover. Under photodegradative conditions, lignin is preferentially degraded because it acts as an effective light-absorbing compound over a wide range of wavelengths. This mechanistic understanding of the role of lignin in plant litter decomposition will allow for more accurate predictions of carbon dynamics in terrestrial ecosystems.

  16. No-till Organic Soybean Production Following a Fall-planted Rye Cover Crop

    OpenAIRE

    Porter, Paul; Feyereisen, Gary; De Bruin, Jason; Johnson, Gregg

    2005-01-01

    The conventional corn-soybean rotation in the United States (USA) is a leaky system with respect to nitrate-nitrogen (nitrate-N), in part because these crops grow only five months of the year. Ecosystem functioning can be improved with the use of an appropriate fall-planted cover crop, but this practice is not common. Organic soybean production in the USA typically relies on delayed planting, crop rotation, intensive harrowing and interrow cultivation for weed control. Research on timing of ...

  17. Ecosystem engineers on plants: indirect facilitation of arthropod communities by leaf-rollers at different scales.

    Science.gov (United States)

    Vieira, Camila; Romero, Gustavo Q

    2013-07-01

    Ecosystem engineering is a process by which organisms change the distribution of resources and create new habitats for other species via non-trophic interactions. Leaf-rolling caterpillars can act as ecosystem engineers because they provide shelter to secondary users. In this study, we report the influence of leaf-rolling caterpillars on speciose tropical arthropod communities along both spatial scales (leaf-level and plant-level effects) and temporal scales (dry and rainy seasons). We predict that rolled leaves can amplify arthropod diversity at both the leaf and plant levels and that this effect is stronger in dry seasons, when arthropods are prone to desiccation. Our results show that the abundance, richness, and biomass of arthropods within several guilds increased up to 22-fold in naturally and artificially created leaf shelters relative to unaltered leaves. These effects were observed at similar magnitudes at both the leaf and plant scales. Variation in the shelter architecture (funnel, cylinders) did not influence arthropod parameters, as diversity, abundance, orbiomass, but rolled leaves had distinct species composition if compared with unaltered leaves. As expected, these arthropod parameters on the plants with rolled leaves were on average approximately twofold higher in the dry season. Empty leaf rolls and whole plants were rapidly recolonized by arthropods over time, implying a fast replacement of individuals; within 15-day intervals the rolls and plants reached a species saturation. This study is the first to examine the extended effects of engineering caterpillars as diversity amplifiers at different temporal and spatial scales. Because shelter-building caterpillars are ubiquitous organisms in tropical and temperate forests, they can be considered key structuring elements for arthropod communities on plants.

  18. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: An ecosustainable approach

    Energy Technology Data Exchange (ETDEWEB)

    Rai, P.K. [Mizoram Central University, Tanhril (India). School for Earth Science & Natural Resource Management

    2008-07-01

    This review addresses the global problem of heavy metal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. Constructed wetlands proved to be effective for the abatement of heavy metal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some of the potent wetland plants for heavy metal removal. Biomass disposal problem and seasonal growth of aquatic macrophytes are some limitations in the transfer of phytoremediation technology from the laboratory to the field. However, the disposed biomass of macrophytes may be used for various fruitful applications. An ecosustainable model has been developed through the author's various works, which may ameliorate some of the limitations. The creation of more areas for phytoremediation may also aid in wetlands conservation. Genetic engineering and biodiversity prospecting of endangered wetland plants are important future prospects in this regard.

  19. Environmental risk assessment for plant pests: a procedure to evaluate their impacts on ecosystem services.

    Science.gov (United States)

    Gilioli, G; Schrader, G; Baker, R H A; Ceglarska, E; Kertész, V K; Lövei, G; Navajas, M; Rossi, V; Tramontini, S; van Lenteren, J C

    2014-01-15

    The current methods to assess the environmental impacts of plant pests differ in their approaches and there is a lack of the standardized procedures necessary to provide accurate and consistent results, demonstrating the complexity of developing a commonly accepted scheme for this purpose. By including both the structural and functional components of the environment threatened by invasive alien species (IAS), in particular plant pests, we propose an environmental risk assessment scheme that addresses this complexity. Structural components are investigated by evaluating the impacts of the plant pest on genetic, species and landscape diversity. Functional components are evaluated by estimating how plant pests modify ecosystem services in order to determine the extent to which an IAS changes the functional traits that influence ecosystem services. A scenario study at a defined spatial and temporal resolution is then used to explore how an IAS, as an exogenous driving force, may trigger modifications in the target environment. The method presented here provides a standardized approach to generate comparable and reproducible results for environmental risk assessment as a component of Pest Risk Analysis. The method enables the assessment of overall environmental risk which integrates the impacts on different components of the environment and their probabilities of occurrence. The application of the proposed scheme is illustrated by evaluating the environmental impacts of the invasive citrus long-horn beetle, Anoplophora chinensis. © 2013.

  20. Pinellas Plant facts. [Products, processes, laboratory facilities

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    This plant was built in 1956 in response to a need for the manufacture of neutron generators, a principal component in nuclear weapons. The neutron generators consist of a miniaturized linear ion accelerator assembled with the pulsed electrical power supplies required for its operation. The ion accelerator, or neutron tube, requires ultra clean, high vacuum technology: hermetic seals between glass, ceramic, glass-ceramic, and metal materials: plus high voltage generation and measurement technology. The existence of these capabilities at the Pinellas Plant has led directly to the assignment of the lightning arrester connector, specialty capacitor, vacuum switch, and crystal resonator. Active and reserve batteries and the radioisotopically-powered thermoelectric generator draw on the materials measurement and controls technologies which are required to ensure neutron generator life. A product development and production capability in alumina ceramics, cermet (electrical) feedthroughs, and glass ceramics has become a specialty of the plant; the laboratories monitor the materials and processes used by the plant's commercial suppliers of ferroelectric ceramics. In addition to the manufacturing facility, a production development capability is maintained at the Pinellas Plant.

  1. Links between plant litter chemistry, species diversity, and below-ground ecosystem function.

    Science.gov (United States)

    Meier, Courtney L; Bowman, William D

    2008-12-16

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics of plant species diversity. We amended native soils with litter mixtures containing up to 4 alpine plant species, and we used 9 litter chemical traits to evaluate the chemical composition (i.e., the identity and quantity of compounds) and chemical diversity of the litter mixtures. The chemical composition of the litter mixtures was the strongest predictor of soil respiration, net N mineralization, and microbial biomass N. Soil respiration and net N mineralization rates were also significantly correlated with the chemical diversity of the litter mixtures. In contrast, soil C and N cycling rates were poorly correlated with plant species richness, and there was no relationship between species richness and the chemical diversity of the litter mixtures. These results indicate that the composition and diversity of chemical compounds in litter are potentially important functional traits affecting decomposition, and simple metrics like plant species richness may fail to capture variation in these traits. Litter chemical traits therefore provide a mechanistic link between organisms, species diversity, and key components of below-ground ecosystem function.

  2. Stakeholder Perceptions of an Ecosystem Services Approach to Clearing Invasive Alien Plants on Private Land

    Directory of Open Access Journals (Sweden)

    Lauren S. Urgenson

    2013-03-01

    Full Text Available Incentivizing private landowners and other stakeholders is central to the effective conservation of ecosystem services in working landscapes. To better understand how to design effective incentives, the perceptions of landowners and other stakeholders are explored regarding a proposed approach to clearing invasive alien plants on private land in the Western Cape Province, South Africa. The public funded national program, Working for Water, conserves ecosystem services while employing and training people from marginalized sectors of society to clear these plants. Private landowner involvement is a key conservation challenge, because without adequate landowner involvement, invasive alien plants persist on the landscape and continuously reinvade cleared areas. We collected interview data from private landowners in three study sites, and web-survey data from conservation professionals and Working for Water managers, in order to compare stakeholder perceptions of (1 government and landowners' responsibilities for clearing invasive alien plants; (2 existing and proposed policy tools; and (3 the extent to which stakeholders consider the proposed financial incentive to be sufficient. There was significant consensus among stakeholders concerning their preference for shared landowner and government responsibility and for a policy mix that combines incentives with disincentives. Landowners from the three study sites differed in the level of responsibility they were willing to assume. Stakeholders also diverged in terms of their perceptions of the proposed financial incentives. Furthermore, the perspectives of landowners were strongly associated with ecological and social features of the landscapes in which they are located. Understanding stakeholders' points of view within their differing contexts is shown to be a valuable means of gaining insight into the opportunities and constraints that face ecosystem service conservation in working landscapes.

  3. Ecosystem-scale fluxes in seminatural Pyrenean grasslands: role of annual dynamics of plant functional types

    Science.gov (United States)

    Altimir, Nuria; Ibañez, Mercedes; Elbers, Jan; Rota, Cristina; Arias, Claudia; Carrara, Arnaud; Nogues, Salvador; Sebastia, Maria-Teresa

    2013-04-01

    The net ecosystem exchange (NEE) and the annual C balance of a site are in general modulated by light, temperature and availability of water and other resources to the plants. In grasslands, NEE is expected to depend strongly on the vegetation with a relationship that can be summarized by the above-ground biomass, its amount and dynamics. Any factor controlling the amount of green biomass is expected to have a strong impact on the short-term NEE, such as amount of solar radiation, water availability and grazing pressure. These controls are modulated differently depending on the plant functional type enduring them. Furthermore, as different guilds follow different functional strategies for optimization of the resources, they also present different patterns of change in their capacities such as photosynthetic fixation, belowground C allocation, and C loss via respiration. We examined these relationships at several semi-natural pastures to determine how the seasonal distribution of plant functional types is detected in the short-term ecosystem exchange and what role it plays. We have looked into these patterns to determine the general variation of key processes and whether different temporal patterns arise between different guilds. The study sites are in the Pyrenees, on the mountain pastures of La Bertolina, Alinyà, and Castellar at 1300, 1700, 1900 m a.s.l. respectively. We performed ecosystem-scale flux measurements by means of micrometeorologial stations combined with a thorough description of the vegetation including below- and above-ground biomass and leaf area as well as monitoring of natural abundance of C isotopes, discriminated by plant functional types. We present here the results of the study.

  4. Internal transport control in pot plant production

    NARCIS (Netherlands)

    Annevelink, E.

    1999-01-01

    Drawing up internal transport schedules in pot plant production is a very complex task. Scheduling internal transport at the operational level and providing control on a day-to-day or even hour-to-hour basis in particular requires a new approach. A hierarchical planning approach based on

  5. Woody-plant ecosystems under climate change and air pollution-response consistencies across zonobiomes?

    Science.gov (United States)

    Matyssek, R; Kozovits, A R; Wieser, G; King, J; Rennenberg, H

    2017-06-01

    Forests store the largest terrestrial pools of carbon (C), helping to stabilize the global climate system, yet are threatened by climate change (CC) and associated air pollution (AP, highlighting ozone (O3) and nitrogen oxides (NOx)). We adopt the perspective that CC-AP drivers and physiological impacts are universal, resulting in consistent stress responses of forest ecosystems across zonobiomes. Evidence supporting this viewpoint is presented from the literature on ecosystem gross/net primary productivity and water cycling. Responses to CC-AP are compared across evergreen/deciduous foliage types, discussing implications of nutrition and resource turnover at tree and ecosystem scales. The availability of data is extremely uneven across zonobiomes, yet unifying patterns of ecosystem response are discernable. Ecosystem warming results in trade-offs between respiration and biomass production, affecting high elevation forests more than in the lowland tropics and low-elevation temperate zone. Resilience to drought is modulated by tree size and species richness. Elevated O3 tends to counteract stimulation by elevated carbon dioxide (CO2). Biotic stress and genomic structure ultimately determine ecosystem responsiveness. Aggrading early- rather than mature late-successional communities respond to CO2 enhancement, whereas O3 affects North American and Eurasian tree species consistently under free-air fumigation. Insect herbivory is exacerbated by CC-AP in biome-specific ways. Rhizosphere responses reflect similar stand-level nutritional dynamics across zonobiomes, but are modulated by differences in tree-soil nutrient cycling between deciduous and evergreen systems, and natural versus anthropogenic nitrogen (N) oversupply. The hypothesis of consistency of forest responses to interacting CC-AP is supported by currently available data, establishing the precedent for a global network of long-term coordinated research sites across zonobiomes to simultaneously advance both

  6. Development of concepts of plants activity, its ecological role and methods of its assessment in ecosystems

    Directory of Open Access Journals (Sweden)

    Savinov Alexander

    2017-09-01

    Full Text Available When studying the species activity in the phytocoenoses, three methodological approaches are used: coenotipic, status and ergontic. The latter is proposed for the first time and based on the fact that the activity of plant organisms of a given species is considered as a set of interactions of these organisms with each other, with other organisms and abiotic components of ecosystems. This interaction essentially reflects the rate of accumulation and generation of substances, energy and information by plant organisms. To calculate the activity of the plant species in this aspect, the appropriate formulas were proposed. When comparing the coenotipic, status and ergontic approaches, it was stated that these approaches can complement each other.

  7. Externalities assessment of a coal power plant in the forest ecosystems in Valdecaballeros Area

    International Nuclear Information System (INIS)

    Laforga, P.; Planas, B.

    1995-01-01

    The book is divided in two parts. The first one analyzes the critical load and level concepts, and the methodological framework for Environmental Impact Statement (E.L.S.). In line with this, critical loads and levels represent the system vulnerability and excedances of critical values identify zones where impacts could occur. These are evaluated according to a set of criteria, talking into account present and future land use, their socio cultural interest, economic value of their natural resources and ecological quality of the whole system. In addition to Environment Impact Statement of air pollutants, the proposed formalism allows assessing the external cost of gaseous emission. The second part applies the developed ideas to a practical case: a hypothetical coal power plant on Valdecaballeros (Badajoz, Spain). Environmental impact on forestry ecosystems is studied on a 70 km radius area around the plant. The assessment of the external costs rely on yield losses associated with gaseous emission of the hypothetical plant. (Author) 100 refs

  8. Rapid top-down regulation of plant C:N:P stoichiometry by grasshoppers in an Inner Mongolia grassland ecosystem.

    Science.gov (United States)

    Zhang, Guangming; Han, Xingguo; Elser, James J

    2011-05-01

    Understanding how food web interactions alter the processing of limiting nutrient elements is an important goal of ecosystem ecology. An experiment manipulating densities of the grasshopper Oedaleus asiaticus was performed to assess top-down effects of grasshoppers on C:N:P stoichiometry of plants and soil in a grassland ecosystem in Inner Mongolia (China). With increased grasshopper feeding, plant biomass declined fourfold, litter abundance increased 30%, and the plant community became dominated by non-host plant taxa. Plant stoichiometric response depended on whether or not the plant was a grasshopper host food species: C:N and C:P ratios increased with increasing grasshopper density (GD) for host plants but decreased in non-host plants. These data suggest either a direct transfer of grasshopper-recycled nutrients from host to non-host plants or a release of non-host plants from nutrient competition with heavily grazed host plants. Litterfall C:N and C:P decreased across moderate levels of grasshopper density but no effects on C:N:P stoichiometry in the surface soil were observed, possibly due to the short experimental period. Our observations of divergent C:N:P stoichiometric response among plant species highlight the important role of grasshopper herbivory in regulating plant community structure and nutrient cycling in grassland ecosystems.

  9. Impact of global climate change on ecosystem-level interactions among sympatric plants from all three photosynthetic pathways. Terminal report

    Energy Technology Data Exchange (ETDEWEB)

    Nobel, P.S.

    1997-12-17

    The proposed research will determine biochemical and physiological responses to variations in environmental factors for plants of all three photosynthetic pathways under competitive situations in the field. These responses will be used to predict the effects of global climatic change on an ecosystem in the northwestern Sonoran Desert where the C{sub 3} subshrub Encelia farinosa, the C{sub 4} bunchgrass Hilaria rigida, and the CAM succulent Agave deserti are co-dominants. These perennials are relatively short with overlapping shallow roots facilitating the experimental measurements as well as leading to competition for soil water. Net CO{sub 2} uptake over 24-h periods measured in the laboratory will be analyzed using an environmental productivity index (EPI) that can incorporate simultaneous effects of soil water, air temperature, and light. Based on EPI, net CO{sub 2} uptake and hence plant productivity will be predicted for the three species in the field under various treatments. Activity of the two CO{sub 2} fixation enzymes, Rubisco and PEPCase, will be determined for these various environmental conditions; also, partitioning of carbon to various organs will be measured based on {sup 14}CO{sub 2} labeling and dry weight analysis. Thus, enzymatic and partitioning controls on competition among sympatric model plants representing all three photosynthetic pathways will be investigated.

  10. Plant hydraulic controls over ecosystem responses to climate-enhanced disturbances

    Science.gov (United States)

    Mackay, D. S.; Ewers, B. E.; Reed, D. E.; Pendall, E.; McDowell, N. G.

    2012-12-01

    Climate-enhanced disturbances such as drought and insect infestation range in severity, contributing minor to severe stress to forests including forest mortality. While neither form of disturbance has been unambiguously implicated as a mechanism of mortality, both induce changes in water, carbon, and nutrient cycling that are key to understanding forest ecosystem response to, and recovery from, disturbance. Each disturbance type has different biophysical, ecohydrological, and biogeochemical signatures that potentially complicate interpretation and development of theory. Plant hydraulic function is arguably a unifying control over these responses to disturbance because it regulates stomatal conductance, leaf biochemistry, carbon (C) uptake and utilization, and nutrient cycling. We demonstrated this idea by focusing on water and C, including non-structural (NSC), resources, and nitrogen (N) uptake across a spectrum of forest ecosystems (e.g., northern temperate mixed forests, lodgepole pine forests in the Rocky Mountains, and pinon pine - juniper woodlands in New Mexico) using the Terrestrial Regional Ecosystem Exchange Simulator (TREES). TREES is grounded in the biophysics of water movement through soil and plants, respectively via hydraulic conductivity of the soil and cavitation of xylem. It combines this dynamic plant hydraulic conductance with canopy biochemical controls over photosynthesis, and the dynamics of structural and non-structural carbon through a carbon budget that responds to plant hydraulic status. As such, the model can be used to develop testable hypotheses on a multitude of disturbance and recovery responses including xylem dysfunction, stomatal and non-stomatal controls on photosynthesis and carbon allocation, respiration, and allocation to defense compounds. For each of the ecosystems we constrained and evaluated the model with allometry, sap flux and/or eddy covariance data, leaf gas exchange measurements, and vulnerability to cavitation data

  11. Heterogeneity of soil surface ammonium concentration and other characteristics, related to plant specific variability in a Mediterranean-type ecosystem

    International Nuclear Information System (INIS)

    Cruz, Cristina; Bio, Ana M.F.; Jullioti, Aldo; Tavares, Alice; Dias, Teresa; Martins-Loucao, Maria Amelia

    2008-01-01

    Heterogeneity and dynamics of eight soil surface characteristics essential for plants-ammonium and nitrate concentrations, water content, temperature, pH, organic matter, nitrification and ammonification rates-were studied in a Mediterranean-type ecosystem on four occasions over a year. Soil properties varied seasonally and were influenced by plant species. Nitrate and ammonium were present in the soil at similar concentrations throughout the year. The positive correlation between them at the time of greatest plant development indicates that ammonium is a readily available nitrogen source in Mediterranean-type ecosystems. The results presented here suggest that plant cover significantly affects soil surface characteristics. - In Mediterranean-type ecosystems ammonium is present in the soil throughout the year and its concentration is dependent on plant cover

  12. Deep Atomic Binding (DAB) Approach in Interpretation of Fission Products Behavior in Terrestrial and Water Ecosystems

    International Nuclear Information System (INIS)

    Ajlouni, Abdul-Wali M.S.

    2006-01-01

    A large number of studies and models were established to explain the fission products (FP) behavior within terrestrial and water ecosystems, but a number of behaviors were non understandable, which always attributed to unknown reasons. According to DAB hypothesis, almost all fission products behaviors in terrestrial and water ecosystems could be interpreted in a wide coincidence. The gab between former models predictions, and field behavior of fission products after accidents like Chernobyl have been explained. DAB represents a tool to reduce radio-phobia as well as radiation protection expenses. (author)

  13. The estimate of ecological risk for ground ecosystems in case of nuclear power plant failures

    International Nuclear Information System (INIS)

    Kremlenkov, D.Y.; Kremlenkov, M.Y.

    2003-01-01

    Full text: The stochastic nature of radiation damage generates a need of forecasting information about possible consequences for environment and people. In this article it is given the estimate of probable damage to forest-and agricultural ecosystems from radionuclide emergency pollution in case of nuclear plant failures (for early emergency period). This estimate is based on radio-ecological risk conception which provide with the application of radioactive substances distribution models in atmosphere, as were calculation of absorbent radiation dose in critical ecosystem groups-calculation of probable area of lost ecosystems has been done by using the program written in Pascal. The quantitative estimate of environmental loss has been conducted for diverse classes of atmospheric stability. The value of ecological dose range (ELD) to coniferous forest is 30 Gy, deciduous forest - 300 Gy, agricultural crop - 60 Gy. The value of minimum ecological dose range (MELD) for all ecosystems is 10 Gy. In dose spread from MELD to ELD the ecological damage is proportional to absorbed dose. The ecological damage to ground ecosystems caused by cesium-137 and strontium-90 emergency pollution is primarily depended on the scale of radionuclide emergency pollution as well as weather conditions and radio-stability of critical vegetal ecosystem groups. On the assumption of a dose spread from MELD to ELD, ecological risk defined in probable ecosystem's destruction area is estimated: for cesium-137 pollution about 2 % of coniferous forest and from 4 to 9 % of deciduous forest; for strontium-90 pollution from 2 to 4 % of agricultural crop. As the scale of cesium-137 emergency pollution rise from 10 4 to 10 5 Cu the probable damage determined in ecosystem's destruction area increase 12-19 times to coniferous forest ecosystem and 15-36 times to deciduous forest according to weather conditions. The probable damage to coniferous and deciduous forest rise 11-17 times in proportion as the scale

  14. Environmental and community controls on plant canopy chemistry in a Mediterranean-type ecosystem.

    Science.gov (United States)

    Dahlin, Kyla M; Asner, Gregory P; Field, Christopher B

    2013-04-23

    Understanding how and why plant communities vary across space has long been a goal of ecology, yet parsing the relative importance of different influences has remained a challenge. Species-specific models are not generalizable, whereas broad plant functional type models lack important detail. Here we consider plant trait patterns at the local scale and ask whether plant chemical traits are more closely linked to environmental gradients or to changes in species composition. We used the visible-to-shortwave infrared (VSWIR) spectrometer of the Carnegie Airborne Observatory to develop maps of four plant chemical traits--leaf nitrogen per mass, leaf carbon per mass, leaf water concentration, and canopy water content--across a diverse Mediterranean-type ecosystem (Jasper Ridge Biological Preserve, CA). For all four traits, plant community alone was the strongest predictor of trait variation (explaining 46-61% of the heterogeneity), whereas environmental gradients accounted for just one fourth of the variation in the traits. This result emphasizes the critical role that species composition plays in mediating nutrient and carbon cycling within and among different communities. Environmental filtering and limits to similarity can act strongly, simultaneously, in a spatially heterogeneous environment, but the local-scale environmental gradients alone cannot account for the variation across this landscape.

  15. Analyses of plant biomarkers in modern ecosystems to improve vegetation reconstructions at hominid sites

    Science.gov (United States)

    Uno, K. T.; Boisserie, J. R.; Cerling, T. E.; Polissar, P. J.

    2017-12-01

    Reconstructing vegetation at hominid localities in eastern Africa remains a significant challenge for examining the role of climate and environment in human evolution. Plant wax biomarker approaches, particularly carbon isotopes of n-alkyl lipids, have been increasingly used to estimate the proportion of C3 and C4­ vegetation in past environments. Identifying new biomarkers indicative of vegetation type, specifically those that can be used to identify (C3) grasses prior to the late Miocene C4 expansion, will enable vegetation reconstructions during the first half of the Neogene, where much remains to be learned about hominid environments. Here, we begin to look beyond carbon isotopes from n-alkyl lipids by analyzing molecular distributions and screening for new plant biomarkers that can be used to identify plant functional types or possibly, more specific taxonomic information. We evaluate molecular distributions, carbon isotope ratios, and pentacyclic triterpenoid methyl esters (PTMEs) in modern soils from a wide range of ecosystems in Ethiopia and Kenya where vegetation types, fraction woody cover, and climatic conditions are known. Preliminary data suggest PTMEs are associated with grassy ecosystems but absent from forested ones. We also find that woody cover can be estimated using n-alkane molecular distributions. This non-isotopic approach to reconstructing woody cover opens the door to reconstructing Neogene vegetation provided the molecular distributions of C3 grasses in the past are similar to those of modern C4 grasses.

  16. Scaling net ecosystem production and net biome production over a heterogeneous region in the Western United States

    Science.gov (United States)

    D.P. Turner; W.D. Ritts; B.E. Law; W.B. Cohen; Z. Yan; T. Hudiburg; J.L. Campbell; M. Duane

    2007-01-01

    Bottom-up scaling of net ecosystem production (NEP) and net biome production (NBP) was used to generate a carbon budget for a large heterogeneous region (the state of Oregon, 2.5x105 km2 ) in the Western United States. Landsat resolution (30 m) remote sensing provided the basis for mapping land cover and disturbance history...

  17. Stochastic resonance and coherence resonance in groundwater-dependent plant ecosystems.

    Science.gov (United States)

    Borgogno, Fabio; D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2012-01-21

    Several studies have shown that non-linear deterministic dynamical systems forced by external random components can give rise to unexpectedly regular temporal behaviors. Stochastic resonance and coherence resonance, the two best known processes of this type, have been studied in a number of physical and chemical systems. Here, we explore their possible occurrence in the dynamics of groundwater-dependent plant ecosystems. To this end, we develop two eco-hydrological models, which allow us to demonstrate that stochastic and coherence resonance may emerge in the dynamics of phreatophyte vegetation, depending on their deterministic properties and the intensity of external stochastic drivers. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Fate of 2,4-D Residues in Turkish Soil-Plant Ecosystems

    International Nuclear Information System (INIS)

    Önal, Q.; Gözek, K.

    1981-01-01

    Full text: 2,4-D is the most frequently used herbicide in Turkish agriculture especially in Middle Anatolia. Studies on the behaviour of 2,4-D in the soil-plant ecosystem is being carried out under laboratory and field conditions. Some preliminary results are reported. After four weeks, recovery of radioactivity in carbon dioxide, aceton extract and bound residue was averaged for various soils: 20%, 15% and 48%, respectively. Barley, wheat and oat grown for four weeks on 2,4-D contaminated soil, contained from 0,6 up to 8% of the radioactivity applied. (author)

  19. Analysis of chemical factors affecting marine ecosystem around nuclear power plant

    International Nuclear Information System (INIS)

    Chun, Kwan Sik; Choi, Yoon Dong; Chun, Ki Jeong; Kim, Jin Kyu; Jung, Kyeong Chai; Lee, Yeong Keun; Park, Hyo Kook

    1994-06-01

    The ecological data of the coastal area of Youngkwang nuclear power plant from 1987 to 1993 were comprehensively analyzed, and various physical and chemical properties of sea water and sediments were measured. Major factors affecting phytoplankton standing crops were suspended substances, nitrate, and silicate. The contents of iron, chromium, copper, and sulfur in sediments sampled from the discharge channel were slightly higher than those in the other areas. In order to qantify the chemical impacts on marine ecosystem, it is desirable that a systematic survey be made through the whole year cycle to assure the consistency and confidence of the related data. (Author)

  20. Plant species richness regulates soil respiration through changes in productivity.

    NARCIS (Netherlands)

    Tavares Correa Dias, A.; van Ruijven, J.; Berendse, F.

    2010-01-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of

  1. Plant species richness regulates soil respiration through changes in productivity

    NARCIS (Netherlands)

    Dias, A.A.; Ruijven, van J.; Berendse, F.

    2010-01-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of

  2. Storm Effects on Net Ecosystem Productivity in Boreal Forests

    Science.gov (United States)

    Vestin, Patrik; Grelle, Achim; Lagergren, Fredrik; Hellström, Margareta; Langvall, Ola; Lindroth, Anders

    2010-05-01

    Regional carbon budgets are to some extent determined by disturbance in ecosystems. Disturbance is believed to be partly responsible for the large inter-annual variability of the terrestrial carbon balance. When neglecting anthropogenic disturbance, forest fires have been considered the most important kind of disturbance. However, also insect outbreaks and wind-throw may be major factors in regional carbon budgets. The effects of wind-throw on CO2 fluxes in boreal forests are not well known due to lack of data. Principally, the reduced carbon sequestration capacity, increased substrate availability and severe soil perturbation following wind-throw are expected to result in increased CO2 fluxes from the forest to the atmosphere. In January 2005, the storm Gudrun hit Sweden, which resulted in approx. 66 × 106m3storm-felled stem wood distributed over an area of approx. 272 000 ha. Eddy covariance flux measurements started at storm-felled areas in Asa and Toftaholm in central Sweden during summer 2005. Data from the first months suggests increased CO2 fluxes by a factor of 2.5-10, as compared to normal silviculture (clear-cutting). An important question is how long such enhanced CO2 fluxes persist. The BIOME-BGC model will be calibrated against measured CO2 fluxes from both sites for 2005 through 2009. Modeled data will be used to fill gaps in the data sets and annual carbon balances will be calculated. Data from Asa and Toftaholm will be presented at the conference.

  3. Sustainable utilization and conservation of plant biodiversity in montane ecosystems: the western Himalayas as a case study.

    Science.gov (United States)

    Khan, Shujaul Mulk; Page, Sue E; Ahmad, Habib; Harper, David M

    2013-08-01

    Conservation of the unique biodiversity of mountain ecosystems needs trans-disciplinary approaches to succeed in a crowded colloquial world. Geographers, conservationists, ecologists and social scientists have, in the past, had the same conservation goals but have tended to work independently. In this review, the need to integrate different conservation criteria and methodologies is discussed. New criteria are offered for prioritizing species and habitats for conservation in montane ecosystems that combine both ecological and social data. Ecological attributes of plant species, analysed through robust community statistical packages, provide unbiased classifications of species assemblages and environmental biodiversity gradients and yield importance value indices (IVIs). Surveys of local communities' utilization of the vegetation provides use values (UVs). This review suggests a new means of assessing anthropogenic pressure on plant biodiversity at both species and community levels by integrating IVI and UV data sets in a combined analysis. Mountain ecosystems are hot spots for plant conservation efforts because they hold a high overall plant diversity as communities replace each other along altitudinal and climatic gradients, including a high proportion of endemic species. This review contributes an enhanced understanding of (1) plant diversity in mountain ecosystems with special reference to the western Himalayas; (2) ethnobotanical and ecosystem service values of mountain vegetation within the context of anthropogenic impacts; and (3) local and regional plant conservation strategies and priorities.

  4. Montane ecosystem productivity responds more to global circulation patterns than climatic trends

    Science.gov (United States)

    Desai, A. R.; Wohlfahrt, G.; Zeeman, M. J.; Katata, G.; Eugster, W.; Montagnani, L.; Gianelle, D.; Mauder, M.; Schmid, H.-P.

    2016-02-01

    Regional ecosystem productivity is highly sensitive to inter-annual climate variability, both within and outside the primary carbon uptake period. However, Earth system models lack sufficient spatial scales and ecosystem processes to resolve how these processes may change in a warming climate. Here, we show, how for the European Alps, mid-latitude Atlantic ocean winter circulation anomalies drive high-altitude summer forest and grassland productivity, through feedbacks among orographic wind circulation patterns, snowfall, winter and spring temperatures, and vegetation activity. Therefore, to understand future global climate change influence to regional ecosystem productivity, Earth systems models need to focus on improvements towards topographic downscaling of changes in regional atmospheric circulation patterns and to lagged responses in vegetation dynamics to non-growing season climate anomalies.

  5. Montane ecosystem productivity responds more to global circulation patterns than climatic trends

    International Nuclear Information System (INIS)

    Desai, A R; Wohlfahrt, G; Zeeman, M J; Katata, G; Mauder, M; Schmid, H-P; Eugster, W; Montagnani, L; Gianelle, D

    2016-01-01

    Regional ecosystem productivity is highly sensitive to inter-annual climate variability, both within and outside the primary carbon uptake period. However, Earth system models lack sufficient spatial scales and ecosystem processes to resolve how these processes may change in a warming climate. Here, we show, how for the European Alps, mid-latitude Atlantic ocean winter circulation anomalies drive high-altitude summer forest and grassland productivity, through feedbacks among orographic wind circulation patterns, snowfall, winter and spring temperatures, and vegetation activity. Therefore, to understand future global climate change influence to regional ecosystem productivity, Earth systems models need to focus on improvements towards topographic downscaling of changes in regional atmospheric circulation patterns and to lagged responses in vegetation dynamics to non-growing season climate anomalies. (letter)

  6. Modelling the diurnal and seasonal dynamics of soil CO2 exchange in a semiarid ecosystem with high plant-interspace heterogeneity

    Science.gov (United States)

    Gong, Jinnan; Wang, Ben; Jia, Xin; Feng, Wei; Zha, Tianshan; Kellomäki, Seppo; Peltola, Heli

    2018-01-01

    We used process-based modelling to investigate the roles of carbon-flux (C-flux) components and plant-interspace heterogeneities in regulating soil CO2 exchanges (FS) in a dryland ecosystem with sparse vegetation. To simulate the diurnal and seasonal dynamics of FS, the modelling considered simultaneously the CO2 production, transport and surface exchanges (e.g. biocrust photosynthesis, respiration and photodegradation). The model was parameterized and validated with multivariate data measured during the years 2013-2014 in a semiarid shrubland ecosystem in Yanchi, northwestern China. The model simulation showed that soil rewetting could enhance CO2 dissolution and delay the emission of CO2 produced from rooting zone. In addition, an ineligible fraction of respired CO2 might be removed from soil volumes under respiration chambers by lateral water flows and root uptakes. During rewetting, the lichen-crusted soil could shift temporally from net CO2 source to sink due to the activated photosynthesis of biocrust but the restricted CO2 emissions from subsoil. The presence of plant cover could decrease the root-zone CO2 production and biocrust C sequestration but increase the temperature sensitivities of these fluxes. On the other hand, the sensitivities of root-zone emissions to water content were lower under canopy, which may be due to the advection of water flows from the interspace to canopy. To conclude, the complexity and plant-interspace heterogeneities of soil C processes should be carefully considered to extrapolate findings from chamber to ecosystem scales and to predict the ecosystem responses to climate change and extreme climatic events. Our model can serve as a useful tool to simulate the soil CO2 efflux dynamics in dryland ecosystems.

  7. Pilot plant study for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J S [Korea Inst. of Science and Technology, Seoul (Korea, Republic of)

    1996-02-01

    Most of domestic alcohol fermentation factory adopt batch process of which productivity is lower than continuous fermentation process. They have made great effort to increase productivity by means of partial unit process automatization and process improvement with their accumulated experience but there is technical limitation in productivity of batch fermentation process. To produce and supply fuel alcohol, economic aspects must be considered first of all. Therefore, development of continuous fermentation process, of which productivity is high, is prerequisite to produce and use fuel alcohol but only a few foreign company possess continuous fermentation technic and use it in practical industrial scale fermentation. We constructed pilot plant (5 Stage CSTR 1 kl 99.5 v/v% ethanol/Day scale) to study some aspects stated below and our ultimate aims are production of industrial scale fuel alcohol and construction of the plant by ourselves. Some study concerned with energy saving separation and contamination control technic were entrusted to KAIST, A-ju university and KIST respectively. (author) 67 refs., 100 figs., 58 tabs.

  8. Microbial community dynamics and transformation of vascular plant detritus in two wetland ecosystems

    International Nuclear Information System (INIS)

    Moran, M.A.

    1987-01-01

    The microbial ecology of two wetland ecosystems in southeastern Georgia, USA, was studied with respect to microbial community dynamics and microbially-mediated transformations of vascular plant detritus. In the Okefenokee Swamp, biomass of microorganisms in the water column and sediments was generally lower in winter months and higher during spring and summer. Biomass and activity (measured as 14 C-lignocellulose mineralization) differed significantly among five habitats within the Okefenokee, and also among locations within each habitat. Significant heterogeneity in the structure of Okefenokee microbial communities was found at scales from 30 cm to 150 m. In field and laboratory studies of vascular plant decomposition in the Okefenokee and a salt marsh on Sapelo Island, the mathematical model which best describes decomposition kinetics is the decaying coefficient model

  9. Interannual variability of net ecosystem productivity in forests is explained by carbon flux phenology in autumn

    DEFF Research Database (Denmark)

    Wu, Chaoyang; Chen, Xi Jing; Black, T. Andrew

    2013-01-01

    To investigate the importance of autumn phenology in controlling interannual variability of forest net ecosystem productivity (NEP) and to derive new phenological metrics to explain the interannual variability of NEP. North America and Europe. Flux data from nine deciduous broadleaf forests (DBF......, soil water content and precipitation, were also used to explain the phenological variations. We found that interannual variability of NEP can be largely explained by autumn phenology, i.e. the autumn lag. While variation in neither annual gross primary productivity (GPP) nor in annual ecosystem...

  10. Drivers of plant species composition in siliceous spring ecosystems: groundwater chemistry, catchment traits or spatial factors?

    Directory of Open Access Journals (Sweden)

    Carl BEIERKUHNLEIN

    2009-08-01

    Full Text Available Spring water reflects the hydrochemistry of the aquifer in the associated catchments. On dense siliceous bedrock, the nearsurface groundwater flow is expected to be closely related to the biogeochemical processes of forest ecosystems, where the impact of land use is also low. We hypothesize that the plant species composition of springs mainly reflects hydrochemical conditions. Therefore, springs may serve as indicator systems for biogeochemical processes in complex forest ecosystems. To test this hypothesis, we investigate the influence of spring water chemical properties, catchment traits, and spatial position on plant species composition for 73 springs in forested catchments in central Germany, using non-metric multidimensional scaling (NMDS, Mantel tests, and path analyses. Partial Mantel tests and path analyses reveal that vegetation is more greatly influenced by spring water chemistry than by catchment traits. Consequently, the catchment's influence on vegetation is effective in an indirect way, via spring water. When considering spatial aspects (in particular altitude in addition, the explanatory power of catchment traits for spring water properties is reduced almost to zero. As vegetation shows the highest correlation with the acidity gradient, we assume that altitude acts as a sum parameter that incorporates various acidifying processes in the catchment. These processes are particularly related to altitude – through bedrock, climatic parameters and forest vegetation. The species composition of undisturbed springs is very sensitive in reflecting such conditions and may serve as an integrative tool for detecting complex ecological processes.

  11. Synergistic linkage between remote sensing and biophysical models for estimating plant ecophysiological and ecosystem processes

    International Nuclear Information System (INIS)

    Inoue, Y.; Olioso, A.

    2004-01-01

    Abstract Information on the ecological and physiological status of crops is essential for growth diagnostics and yield prediction. Within-field or between-field spatial information is required, especially with the recent trend toward precision agriculture, which seeks the efficient use of agrochemicals, water, and energy. The study of carbon and nitrogen cycles as well as environmental management on local and regional scales requires assessment of the spatial variability of biophysical and ecophysiological variables, scaling up of which is also needed for scientific and decision-making purposes. Remote sensing has great potential for these applications because it enables wide-area non-destructive, and real-time acquisition of information about ecophysiological conditions of vegetation. With recent advances in sensor technology, a variety of electromagnetic signatures, such as hyperspectral reflectance, thermal-infrared temperature, and microwave backscattering coefficients, can be acquired for both plants and ecosystems using ground-based, airborne, and satellite platforms. Their spatial and temporal resolutions have both recently been improved. This article reviews the state of the art in the remote sensing of plant ecophysiological data, with special emphasis on the synergy between remote sensing signatures and biophysical and ecophysiological process models. Several case studies for the optical, thermal, and microwave domains have demonstrated the potential of this synergistic linkage. Remote sensing and process modeling methods complement each other when combined synergistically. Further research on this approach is needed f or a wide range of ecophysiological and ecosystem studies, as well as for practical crop management

  12. Dynamics of microbial communities during decomposition of litter from pioneering plants in initial soil ecosystems

    Directory of Open Access Journals (Sweden)

    J. Esperschütz

    2013-07-01

    Full Text Available In initial ecosystems, concentrations of all macro- and micronutrients can be considered as extremely low. Plant litter therefore strongly influences the development of a degrader's food web and is an important source for C and N input into soil in such ecosystems. In the present study, a 13C litter decomposition field experiment was performed for 30 weeks in initial soils from a post-mining area near the city of Cottbus (Germany. Two of this region's dominant but contrasting pioneering plant species (Lotus corniculatus L. and Calamagrostis epigejos L. were chosen to investigate the effects of litter quality on the litter decomposing microbial food web in initially nutrient-poor substrates. The results clearly indicate the importance of litter quality, as indicated by its N content, its bioavailability for the degradation process and the development of microbial communities in the detritusphere and soil. The degradation of the L. corniculatus litter, which had a low C / N ratio, was fast and showed pronounced changes in the microbial community structure 1–4 weeks after litter addition. The degradation of the C. epigejos litter material was slow and microbial community changes mainly occurred between 4 and 30 weeks after litter addition to the soil. However, for both litter materials a clear indication of the importance of fungi for the degradation process was observed both in terms of fungal abundance and activity (13C incorporation activity

  13. Nutrient limitation on ecosystem productivity and processes of mature and old-growth subtropical forests in China.

    Directory of Open Access Journals (Sweden)

    Enqing Hou

    Full Text Available Nitrogen (N is considered the dominant limiting nutrient in temperate regions, while phosphorus (P limitation frequently occurs in tropical regions, but in subtropical regions nutrient limitation is poorly understood. In this study, we investigated N and P contents and N:P ratios of foliage, forest floors, fine roots and mineral soils, and their relationships with community biomass, litterfall C, N and P productions, forest floor turnover rate, and microbial processes in eight mature and old-growth subtropical forests (stand age >80 yr at Dinghushan Biosphere Reserve, China. Average N:P ratios (mass based in foliage, litter (L layer and mixture of fermentation and humus (F/H layer, and fine roots were 28.3, 42.3, 32.0 and 32.7, respectively. These values are higher than the critical N:P ratios for P limitation proposed (16-20 for foliage, ca. 25 for forest floors. The markedly high N:P ratios were mainly attributed to the high N concentrations of these plant materials. Community biomass, litterfall C, N and P productions, forest floor turnover rate and microbial properties were more strongly related to measures of P than N and frequently negatively related to the N:P ratios, suggesting a significant role of P availability in determining ecosystem production and productivity and nutrient cycling at all the study sites except for one prescribed disturbed site where N availability may also be important. We propose that N enrichment is probably a significant driver of the potential P limitation in the study area. Low P parent material may also contribute to the potential P limitation. In general, our results provided strong evidence supporting a significant role for P availability, rather than N availability, in determining ecosystem primary productivity and ecosystem processes in subtropical forests of China.

  14. Ecosystem development after mangrove wetland creation: plant-soil change across a 20-year chronosequence

    Science.gov (United States)

    Osland, Michael J.; Spivak, Amanda C.; Nestlerode, Janet A.; Lessmann, Jeannine M.; Almario, Alejandro E.; Heitmuller, Paul T.; Russell, Marc J.; Krauss, Ken W.; Alvarez, Federico; Dantin, Darrin D.; Harvey, James E.; From, Andrew S.; Cormier, Nicole; Stagg, Camille L.

    2012-01-01

    Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland losses. However, ecosystem development and functional equivalence in restored and created mangrove wetlands are poorly understood. We compared a 20-year chronosequence of created tidal wetland sites in Tampa Bay, Florida (USA) to natural reference mangrove wetlands. Across the chronosequence, our sites represent the succession from salt marsh to mangrove forest communities. Our results identify important soil and plant structural differences between the created and natural reference wetland sites; however, they also depict a positive developmental trajectory for the created wetland sites that reflects tightly coupled plant-soil development. Because upland soils and/or dredge spoils were used to create the new mangrove habitats, the soils at younger created sites and at lower depths (10-30 cm) had higher bulk densities, higher sand content, lower soil organic matter (SOM), lower total carbon (TC), and lower total nitrogen (TN) than did natural reference wetland soils. However, in the upper soil layer (0-10 cm), SOM, TC, and TN increased with created wetland site age simultaneously with mangrove forest growth. The rate of created wetland soil C accumulation was comparable to literature values for natural mangrove wetlands. Notably, the time to equivalence for the upper soil layer of created mangrove wetlands appears to be faster than for many other wetland ecosystem types. Collectively, our findings characterize the rate and trajectory of above- and below-ground changes associated with ecosystem development in created mangrove wetlands; this is valuable information for environmental managers planning to sustain existing mangrove wetlands or mitigate for mangrove wetland losses.

  15. Biological invasion by Myrica faya in Hawaii: Plant demography, nitrogen fixation, ecosystem effects

    International Nuclear Information System (INIS)

    Vitousek, P.M.; Walker, L.R.

    1989-01-01

    Myrica faya, an introduced actinorhizal nitrogen fixer, in invading young volcanic sites in Hawaii Volcanoes National Park. We examined the population biology of the invader and ecosystem-level consequences of its invasion in open-canopied forests resulting from volcanic cinder-fall. Although Myrica faya is nominally dioecious, both males and females produce large amounts of fruit that are utilized by a number of exotic and native birds, particularly the exotic Zosterops japonica. In areas of active colonization, Myrica seed rain under perch trees of the dominant native Metrosideros polymorpha ranged from 6 to 60 seeds m -2 yr -1 ; no seeds were captured in the open. Planted seeds of Myrica also germinated an established better under isolated individuals of Metrosideros than in the open. Diameter growth of Myrica is > 15-fold greater than that of Metrosideros, and the Myrica population is increasing rapidly. Rates of nitrogen fixation were measured using the acetylene reduction assay calibrated with 15 N. Myrica nodules reduced acetylene at between 5 and 20 μmol g -1 h -1 , a rate that extrapolated to nitrogen fixation of 18 kg ha -1 in a densely colonized site. By comparison, all native sources of nitrogen fixation summed to 0.2 kg ha -1 yr -1 , and precipitation added -1 yr -1 . Measurements of litter decomposition and nitrogen release, soil nitrogen mineralization, and plant growth in bioassays all demonstrated that nitrogen fixed by Myrica becomes available to other organisms as well. We conclude that biological invasion by Myrica faya alters ecosystem-level properties in this young volcanic area; at least in this case, the demography and physiology of one species controls characteristics of a whole ecosystem

  16. Spring fasting behavior in a marine apex predator provides an index of ecosystem productivity

    Science.gov (United States)

    Rode, Karyn D.; Wilson, Ryan R.; Douglas, David C.; Muhlenbruch, Vanessa L; Atwood, Todd C.; Regehr, Eric V.; Richardson, Evan; Pilfold, Nicholas; Derocher, Andrew E.; Durner, George M.; Stirling, Ian; Amstrup, Steven C.; St Martin, Michelle; Pagano, Anthony M.; Simac, Kristin

    2018-01-01

    The effects of declining Arctic sea ice on local ecosystem productivity are not well understood but have been shown to vary inter-specifically, spatially, and temporally. Because marine mammals occupy upper trophic levels in Arctic food webs, they may be useful indicators for understanding variation in ecosystem productivity. Polar bears (Ursus maritimus) are apex predators that primarily consume benthic and pelagic-feeding ice-associated seals. As such, their productivity integrates sea ice conditions and the ecosystem supporting them. Declining sea ice availability has been linked to negative population effects for polar bears but does not fully explain observed population changes. We examined relationships between spring foraging success of polar bears and sea ice conditions, prey productivity, and general patterns of ecosystem productivity in the Beaufort and Chukchi Seas (CSs). Fasting status (≥7 days) was estimated using serum urea and creatinine levels of 1,448 samples collected from 1,177 adult and subadult bears across three subpopulations. Fasting increased in the Beaufort Sea between 1983–1999 and 2000–2016 and was related to an index of ringed seal body condition. This change was concurrent with declines in body condition of polar bears and observed changes in the diet, condition and/or reproduction of four other vertebrate consumers within the food chain. In contrast, fasting declined in CS polar bears between periods and was less common than in the two Beaufort Sea subpopulations consistent with studies demonstrating higher primary productivity and maintenance or improved body condition in polar bears, ringed seals, and bearded seals despite recent sea ice loss in this region. Consistency between regional and temporal variation in spring polar bear fasting and food web productivity suggests that polar bears may be a useful indicator species. Furthermore, our results suggest that spatial and temporal ecological variation is important in

  17. Modelling impacts of second generation bioenergy production on Ecosystem Services in Europe

    Science.gov (United States)

    Henner, Dagmar; Smith, Pete; Davies, Christian; McNamara, Niall

    2016-04-01

    Bioenergy crops are an important source of renewable energy and are a possible mechanism to mitigate global climate warming, by replacing fossil fuel energy with higher greenhouse gas emissions. There is, however, uncertainty about the impacts of the growth of bioenergy crops on ecosystem services. This uncertainty is further enhanced by the unpredictable climate change currently going on. The goal of this project is to develop a comprehensive model that covers high impact, policy relevant ecosystem services at a Continental scale including biodiversity and pollination, water and air security, erosion control and soil security, GHG emissions, soil C and cultural services like tourism value. The technical distribution potential and likely yield of second generation energy crops, such as Miscanthus, Short Rotation Coppice (SRC) with willow, poplar, eucalyptus and other broadleaf species and Short Rotation Forestry (SRF), is currently being modelled using ECOSSE, DayCent, SalixFor and MiscanFor, and ecosystem models will be used to examine the impacts of these crops on ecosystem services. The project builds on models of energy crop production, biodiversity, soil impacts, greenhouse gas emissions and other ecosystem services, and on work undertaken in the UK on the ETI-funded ELUM project (www.elum.ac.uk). In addition, methods like water footprint tools, tourism value maps and ecosystem valuation tools and models (e.g. InVest, TEEB database, GREET LCA Model, World Business Council for Sustainable Development corporate ecosystem valuation, Millennium Ecosystem Assessment and the Ecosystem Services Framework) will be utilised. Research will focus on optimisation of land use change feedbacks on above named ecosystem services, impact on food security, land management practices and impacts from climate change. We will present results for GHG emissions and soil organic carbon change after different land use change scenarios (e.g. arable to Miscanthus, forest to SRF), and

  18. Do plant-based amendments improve soil physiochemical and microbiological properties and plant growth in dryland ecosystems?

    Science.gov (United States)

    Kneller, Tayla; Harris, Richard; Muñoz-Rojas, Miriam

    2017-04-01

    , these include Triodia wiseana, Triodia wiseana and Acacia ancistrocarpa and a combination of the former species with Grevillia wickhamii. Pots were filled with soil materials and allocated plant community treatments. Plant growth and morphology, soil physiochemical (pH, electrical conductivity, N and organic C) and biological (microbial activity) properties were measured after 12 months to assess the suitability of the amendments. Results Our results have demonstrated a general decline in plant survival over the duration of 12 months, where pots with amended mine soils displaying the lowest survival rates compared to the topsoil. However, soil microbial activity of pots containing amendments was greater than those without, although there was no significant difference in microbial activity across vegetation communities (p ldr.2660 Muñoz-Rojas M, Erickson TE, Dixon KW, Merritt DJ. 2016. Soil quality indicators to assess functionality of restored soils in degraded semiarid ecosystems. Restoration Ecology 24, 43-52. DOI: 10.1111/rec.12368

  19. Aquatic plant Azolla as the universal feedstock for biofuel production.

    Science.gov (United States)

    Miranda, Ana F; Biswas, Bijoy; Ramkumar, Narasimhan; Singh, Rawel; Kumar, Jitendra; James, Anton; Roddick, Felicity; Lal, Banwari; Subudhi, Sanjukta; Bhaskar, Thallada; Mouradov, Aidyn

    2016-01-01

    The quest for sustainable production of renewable and cheap biofuels has triggered an intensive search for domestication of the next generation of bioenergy crops. Aquatic plants which can rapidly colonize wetlands are attracting attention because of their ability to grow in wastewaters and produce large amounts of biomass. Representatives of Azolla species are some of the fastest growing plants, producing substantial biomass when growing in contaminated water and natural ecosystems. Together with their evolutional symbiont, the cyanobacterium Anabaena azollae, Azolla biomass has a unique chemical composition accumulating in each leaf including three major types of bioenergy molecules: cellulose/hemicellulose, starch and lipids, resembling combinations of terrestrial bioenergy crops and microalgae. The growth of Azolla filiculoides in synthetic wastewater led up to 25, 69, 24 and 40 % reduction of NH 4 -N, NO 3 -N, PO 4 -P and selenium, respectively, after 5 days of treatment. This led to a 2.6-fold reduction in toxicity of the treated wastewater to shrimps, common inhabitants of wetlands. Two Azolla species, Azolla filiculoides and Azolla pinnata, were used as feedstock for the production of a range of functional hydrocarbons through hydrothermal liquefaction, bio-hydrogen and bio-ethanol. Given the high annual productivity of Azolla, hydrothermal liquefaction can lead to the theoretical production of 20.2 t/ha-year of bio-oil and 48 t/ha-year of bio-char. The ethanol production from Azolla filiculoides, 11.7 × 10 3  L/ha-year, is close to that from corn stover (13.3 × 10 3  L/ha-year), but higher than from miscanthus (2.3 × 10 3  L/ha-year) and woody plants, such as willow (0.3 × 10 3  L/ha-year) and poplar (1.3 × 10 3  L/ha-year). With a high C/N ratio, fermentation of Azolla biomass generates 2.2 mol/mol glucose/xylose of hydrogen, making this species a competitive feedstock for hydrogen production compared with other bioenergy crops

  20. Design of a lunar oxygen production plant

    Science.gov (United States)

    Radhakrishnan, Ramalingam

    1990-01-01

    To achieve permanent human presence and activity on the moon, oxygen is required for both life support and propulsion. Lunar oxygen production using resources existing on the moon will reduce or eliminate the need to transport liquid oxygen from earth. In addition, the co-products of oxygen production will provide metals, structural ceramics, and other volatile compounds. This will enable development of even greater self-sufficiency as the lunar outpost evolves. Ilmenite is the most abundant metal-oxide mineral in the lunar regolith. A process involving the reaction of ilmenite with hydrogen at 1000 C to produce water, followed by the electrolysis of this water to provide oxygen and recycle the hydrogen has been explored. The objective of this 1990 Summer Faculty Project was to design a lunar oxygen-production plant to provide 5 metric tons of liquid oxygen per year from lunar soil. The results of this study describe the size and mass of the equipment, the power needs, feedstock quantity and the engineering details of the plant.

  1. Response of photosynthetic carbon gain to ecosystem retrogression of vascular plants and mosses in the boreal forest.

    Science.gov (United States)

    Bansal, Sheel; Nilsson, Marie-Charlotte; Wardle, David A

    2012-07-01

    In the long-term absence of rejuvenating disturbances, forest succession frequently proceeds from a maximal biomass phase to a retrogressive phase characterized by reduced nutrient availability [notably nitrogen (N) and phosphorus (P)] and net primary productivity. Few studies have considered how retrogression induces changes in ecophysiological responses associated with photosynthetic carbon (C) gain, and only for trees. We tested the hypothesis that retrogression would negatively impact photosynthetic C gain of four contrasting species, and that this impact would be greater for vascular plants (i.e., trees and shrubs) than for non-vascular plants (i.e., mosses). We used a 5,000-year-old chronosequence of forested islands in Sweden, where retrogression occurs in the long-term absence of lightning-ignited wildfires. Despite fundamental differences in plant form and ecological niche among species, vascular plants and mosses showed similar ecophysiological responses to retrogression. The most common effects of retrogression were reductions in photosynthesis and respiration per unit foliar N, increases in foliar N, δ(13)C and δ(15)N, and decreases in specific leaf areas. In contrast, photosynthesis per unit mass or area generally did not change along the chronosequence, but did vary many-fold between vascular plants and mosses. The consistent increases in foliar N without corresponding increases in mass- or area-based photosynthesis suggest that other factor(s), such as P co-limitation, light conditions or water availability, may co-regulate C gain in retrogressive boreal forests. Against our predictions, traits of mosses associated with C and N were generally highly responsive to retrogression, which has implications for how mosses influence ecosystem processes in boreal forests.

  2. Biogeochemical modelling vs. tree-ring data - comparison of forest ecosystem productivity estimates

    Science.gov (United States)

    Zorana Ostrogović Sever, Maša; Barcza, Zoltán; Hidy, Dóra; Paladinić, Elvis; Kern, Anikó; Marjanović, Hrvoje

    2017-04-01

    Forest ecosystems are sensitive to environmental changes as well as human-induce disturbances, therefore process-based models with integrated management modules represent valuable tool for estimating and forecasting forest ecosystem productivity under changing conditions. Biogeochemical model Biome-BGC simulates carbon, nitrogen and water fluxes, and it is widely used for different terrestrial ecosystems. It was modified and parameterised by many researchers in the past to meet the specific local conditions. In this research, we used recently published improved version of the model Biome-BGCMuSo (BBGCMuSo), with multilayer soil module and integrated management module. The aim of our research is to validate modelling results of forest ecosystem productivity (NPP) from BBGCMuSo model with observed productivity estimated from an extensive dataset of tree-rings. The research was conducted in two distinct forest complexes of managed Pedunculate oak in SE Europe (Croatia), namely Pokupsko basin and Spačva basin. First, we parameterized BBGCMuSo model at a local level using eddy-covariance (EC) data from Jastrebarsko EC site. Parameterized model was used for the assessment of productivity on a larger scale. Results of NPP assessment with BBGCMuSo are compared with NPP estimated from tree ring data taken from trees on over 100 plots in both forest complexes. Keywords: Biome-BGCMuSo, forest productivity, model parameterization, NPP, Pedunculate oak

  3. Community production modulates coral reef pH and the sensitivity of ecosystem calcification to ocean acidification

    Science.gov (United States)

    DeCarlo, Thomas M.; Cohen, Anne L.; Wong, George T. F.; Shiah, Fuh-Kwo; Lentz, Steven J.; Davis, Kristen A.; Shamberger, Kathryn E. F.; Lohmann, Pat

    2017-01-01

    Coral reefs are built of calcium carbonate (CaCO3) produced biogenically by a diversity of calcifying plants, animals, and microbes. As the ocean warms and acidifies, there is mounting concern that declining calcification rates could shift coral reef CaCO3 budgets from net accretion to net dissolution. We quantified net ecosystem calcification (NEC) and production (NEP) on Dongsha Atoll, northern South China Sea, over a 2 week period that included a transient bleaching event. Peak daytime pH on the wide, shallow reef flat during the nonbleaching period was ˜8.5, significantly elevated above that of the surrounding open ocean (˜8.0-8.1) as a consequence of daytime NEP (up to 112 mmol C m-2 h-1). Diurnal-averaged NEC was 390 ± 90 mmol CaCO3 m-2 d-1, higher than any other coral reef studied to date despite comparable calcifier cover (25%) and relatively high fleshy algal cover (19%). Coral bleaching linked to elevated temperatures significantly reduced daytime NEP by 29 mmol C m-2 h-1. pH on the reef flat declined by 0.2 units, causing a 40% reduction in NEC in the absence of pH changes in the surrounding open ocean. Our findings highlight the interactive relationship between carbonate chemistry of coral reef ecosystems and ecosystem production and calcification rates, which are in turn impacted by ocean warming. As open-ocean waters bathing coral reefs warm and acidify over the 21st century, the health and composition of reef benthic communities will play a major role in determining on-reef conditions that will in turn dictate the ecosystem response to climate change.

  4. Hyperspectral remote sensing application for monitoring and preservation of plant ecosystems

    Science.gov (United States)

    Krezhova, Dora; Maneva, Svetla; Zdravev, Tomas; Petrov, Nikolay; Stoev, Antoniy

    Remote sensing technologies have advanced significantly at last decade and have improved the capability to gather information about Earth’s resources and environment. They have many applications in Earth observation, such as mapping and updating land-use and cover, weather forecasting, biodiversity determination, etc. Hyperspectral remote sensing offers unique opportunities in the environmental monitoring and sustainable use of natural resources. Remote sensing sensors on space-based platforms, aircrafts, or on ground, are capable of providing detailed spectral, spatial and temporal information on terrestrial ecosystems. Ground-based sensors are used to record detailed information about the land surface and to create a data base for better characterizing the objects which are being imaged by the other sensors. In this paper some applications of two hyperspectral remote sensing techniques, leaf reflectance and chlorophyll fluorescence, for monitoring and assessment of the effects of adverse environmental conditions on plant ecosystems are presented. The effect of stress factors such as enhanced UV-radiation, acid rain, salinity, viral infections applied to some young plants (potato, pea, tobacco) and trees (plums, apples, paulownia) as well as of some growth regulators were investigated. Hyperspectral reflectance and fluorescence data were collected by means of a portable fiber-optics spectrometer in the visible and near infrared spectral ranges (450-850 nm and 600-900 nm), respectively. The differences between the reflectance data of healthy (control) and injured (stressed) plants were assessed by means of statistical (Student’s t-criterion), first derivative, and cluster analysis and calculation of some vegetation indices in four most informative for the investigated species regions: green (520-580 nm), red (640-680 nm), red edge (690-720 nm) and near infrared (720-780 nm). Fluorescence spectra were analyzed at five characteristic wavelengths located at the

  5. How ecosystems change following invasion by Robinia pseudoacacia: Insights from soil chemical properties and soil microbial, nematode, microarthropod and plant communities.

    Science.gov (United States)

    Lazzaro, Lorenzo; Mazza, Giuseppe; d'Errico, Giada; Fabiani, Arturo; Giuliani, Claudia; Inghilesi, Alberto F; Lagomarsino, Alessandra; Landi, Silvia; Lastrucci, Lorenzo; Pastorelli, Roberta; Roversi, Pio Federico; Torrini, Giulia; Tricarico, Elena; Foggi, Bruno

    2018-05-01

    Biological invasions are a global threat to biodiversity. Since the spread of invasive alien plants may have many impacts, an integrated approach, assessing effects across various ecosystem components, is needed for a correct understanding of the invasion process and its consequences. The nitrogen-fixing tree Robinia pseudoacacia (black locust) is a major invasive species worldwide and is used in forestry production. While its effects on plant communities and soils are well known, there have been few studies on soil fauna and microbes. We investigated the impacts of the tree on several ecosystem components, using a multi-trophic approach to combine evidence of soil chemical properties and soil microbial, nematode, microarthropod and plant communities. We sampled soil and vegetation in managed forests, comparing those dominated by black locust with native deciduous oak stands. We found qualitative and quantitative changes in all components analysed, such as the well-known soil nitrification and acidification in stands invaded by black locust. Bacterial richness was the only component favoured by the invasion. On the contrary, abundance and richness of microarthropods, richness of nematodes, and richness and diversity of plant communities decreased significantly in invaded stands. The invasion process caused a compositional shift in all studied biotic communities and in relationships between the different ecosystem components. We obtained clear insights into the effects of invasion of managed native forests by black locust. Our data confirms that the alien species transforms several ecosystem components, modifying the plant-soil community and affecting biodiversity at different levels. Correct management of this aggressive invader in temperate forests is urgently required. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Antibody Production in Plants and Green Algae.

    Science.gov (United States)

    Yusibov, Vidadi; Kushnir, Natasha; Streatfield, Stephen J

    2016-04-29

    Monoclonal antibodies (mAbs) have a wide range of modern applications, including research, diagnostic, therapeutic, and industrial uses. Market demand for mAbs is high and continues to grow. Although mammalian systems, which currently dominate the biomanufacturing industry, produce effective and safe recombinant mAbs, they have a limited manufacturing capacity and high costs. Bacteria, yeast, and insect cell systems are highly scalable and cost effective but vary in their ability to produce appropriate posttranslationally modified mAbs. Plants and green algae are emerging as promising production platforms because of their time and cost efficiencies, scalability, lack of mammalian pathogens, and eukaryotic posttranslational protein modification machinery. So far, plant- and algae-derived mAbs have been produced predominantly as candidate therapeutics for infectious diseases and cancer. These candidates have been extensively evaluated in animal models, and some have shown efficacy in clinical trials. Here, we review ongoing efforts to advance the production of mAbs in plants and algae.

  7. Net ecosystem productivity of temperate and boreal forests after clearcutting a Fluxnet-Canada measurement and modelling synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Grant, R. F. (Dept. of Renewable Resources, Univ. of Alberta, Edmonton, (Canada)), e-mail: robert.grant@ales.ualberta.ca; Barr, A. G. (Climate Research Branch, Meteorological Service of Canada, Saskatoon (Canada)); Black, T. A. (Faculty of Land and Food Systems, Univ. of British Columbia, Vancouver BC, (Canada)); Margolis, H. A. (Faculte de Foresterie et de Geomatique, Pavillon Abitibi-Price, Universite Laval, Quebec (Canada)); McCaughey, J. H. (Dept. of Geography, Queen' s Univ., Kingston (Canada)); Trofymow, J. A. (Canadian Forest Service, Pacific Forestry Centre, Victoria (Canada))

    2010-11-15

    Clearcutting strongly affects subsequent forest net ecosystem productivity (NEP). Hypotheses for ecological controls on NEP in the ecosystem model ecosys were tested with CO{sub 2} fluxes measured by eddy covariance (EC) in three post clearcut conifer chronosequences in different ecological zones across Canada. In the model, microbial colonization of postharvest fine and woody debris drove heterotrophic respiration (Rh), and hence decomposition, microbial growth, N mineralization and asymbiotic N{sub 2} fixation. These processes controlled root N uptake, and thereby CO{sub 2} fixation in regrowing vegetation. Interactions among soil and plant processes allowed the model to simulate hourly CO{sub 2} fluxes and annual NEP within the uncertainty of EC measurements from 2003 to 2007 over forest stands from 1 to 80 yr of age in all three chronosequences without site- or species-specific parameterization. The model was then used to study the impacts of increasing harvest removals on subsequent C stocks at one of the chronosequence sites. Model results indicated that increasing harvest removals would hasten recovery of NEP during the first 30 yr after clearcutting, but would reduce ecosystem C stocks by about 15% of the increased removals at the end of an 80-yr harvest cycle

  8. Disturbance, complexity, and succession of net ecosystem production in North America’s temperate deciduous forests

    Energy Technology Data Exchange (ETDEWEB)

    Gough, Christopher; Curtis, Peter; Hardiman, Brady; Scheuermann, Cynthia; Bond-Lamberty, Benjamin

    2016-06-29

    Century-old forests in the U.S. upper Midwest and Northeast power much of North Amer- ica’s terrestrial carbon (C) sink, but these forests’ production and C sequestration capacity are expected to soon decline as fast-growing early successional species die and are replaced by slower growing late successional species. But will this really happen? Here we marshal empirical data and ecological theory to argue that substantial declines in net ecosystem production (NEP) owing to reduced forest growth, or net primary production (NPP), are not imminent in regrown temperate deciduous forests over the next several decades. Forest age and production data for temperate deciduous forests, synthesized from published literature, suggest slight declines in NEP and increasing or stable NPP during middle successional stages. We revisit long-held hypotheses by EP Odum and others that suggest low-severity, high-frequency disturbances occurring in the region’s aging forests will, against intuition, maintain NEP at higher-than- expected rates by increasing ecosystem complexity, sustaining or enhancing NPP to a level that largely o sets rising C losses as heterotrophic respiration increases. This theoretical model is also supported by biological evidence and observations from the Forest Accelerated Succession Experiment in Michigan, USA. Ecosystems that experience high-severity disturbances that simplify ecosystem complexity can exhibit substantial declines in production during middle stages of succession. However, observations from these ecosystems have exerted a disproportionate in uence on assumptions regarding the trajectory and magnitude of age-related declines in forest production. We conclude that there is a wide ecological space for forests to maintain NPP and, in doing so, lessens the declines in NEP, with signi cant implications for the future of the North American carbon sink. Our intellectual frameworks for understanding forest C cycle dynamics and resilience need to

  9. Resource partitioning within major bottom fish species in a highly productive upwelling ecosystem

    Science.gov (United States)

    Abdellaoui, Souad; El Halouani, Hassan; Tai, Imane; Masski, Hicham

    2017-09-01

    The Saharan Bank (21-26°N) is a wide subtropical continental shelf and a highly productive upwelling ecosystem. The bottom communities are dominated by octopus and sparid fish, which are the main targets of bottom-trawl fishing fleets. To investigate resource partitioning within the bottom fish community, adult fish from 14 of the most abundant species were investigated for stomach content analysis. Samples were collected during two periods: October 2003 and May 2007. The diet of the analysed species showed more variation between periods than between size classes, suggesting that temporal or spatial variability in prey availability appears to play a significant role in their diet. Multivariate analysis and subsequent clustering led to a grouping of the species within five trophic guilds. Two species were fish feeders, and the others mainly fed on benthic invertebrates, where epibenthic crustaceans, lamellibranchs and fish were the most important groups in defining trophic guilds. We found that the studied species had a high rate of overlapping spatial distributions and overlapping trophic niches. In this highly productive upwelling ecosystem, where food resources may not be a limiting factor, inter-specific competition did not appear to be an important factor in structuring bottom fish communities. For the species that showed differences in the proportions of prey categories in comparison with other ecosystems, the rise of the proportion of epibenthic crustaceans in their diet was a common feature; a possible consequence of the benthic productivity of this highly productive upwelling ecosystem.

  10. Disturbance and net ecosystem production across three climatically distinct forest landscapes

    Science.gov (United States)

    John L. Campbell; O.J. Sun; B.E. Law

    2004-01-01

    Biometric techniques were used to measure net ecosystem production (NEP) across three climatically distinct forest chronosequences in Oregon. NEP was highly negative immediately following stand-replacing disturbance in all forests and recovered to positive values by 10, 20, and 30 years of age for the mild mesic Coast Range, mesic West Cascades, and semi-arid East...

  11. Sustainability and productivity of southern pine ecosystems: A thematic framework for integrating research and building partnerships

    Science.gov (United States)

    Charles K. McMahon; James P. Barnett

    2000-01-01

    In 1997, the USDA Forest Service Southern Research Station (SRS) published a Strategic Plan that formed a framework for addressing the Sustainability of Southern Forest Ecosystems. Six crosscutting themes were identified to facilitate research integration and partnership building among the widely dispersed SRS research work units. The Sustainability and Productivity of...

  12. Role of Osmotic Adjustment in Plant Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Gebre, G.M.

    2001-01-11

    Successful implementation of short rotation woody crops requires that the selected species and clones be productive, drought tolerant, and pest resistant. Since water is one of the major limiting factors in poplar (Populus sp.) growth, there is little debate for the need of drought tolerant clones, except on the wettest of sites (e.g., lower Columbia River delta). Whether drought tolerance is compatible with productivity remains a debatable issue. Among the many mechanisms of drought tolerance, dehydration postponement involves the maintenance of high leaf water potential due to, for example, an adequate root system. This trait is compatible with productivity, but requires available soil moisture. When the plant leaf water potential and soil water content decline, the plant must be able to survive drought through dehydration tolerance mechanisms, such as low osmotic potential or osmotic adjustment. Osmotic adjustment and low osmotic potential are considered compatible with growth and yield because they aid in the maintenance of leaf turgor. However, it has been shown that turgor alone does not regulate cell expansion or stomatal conductance and, therefore, the role of osmotic adjustment is debated. Despite this finding, osmotic adjustment has been correlated with grain yield in agronomic crop species, and gene markers responsible for osmotic adjustment are being investigated to improve drought tolerance in productive progenies. Although osmotic adjustment and low osmotic potentials have been investigated in several forest tree species, few studies have investigated the relationship between osmotic adjustment and growth. Most of these studies have been limited to greenhouse or container-grown plants. Osmotic adjustment and rapid growth have been specifically associated in Populus and black spruce (Picea mariuna (Mill.) B.S.P.) progenies. We tested whether these relationships held under field conditions using several poplar clones. In a study of two hybrid poplar

  13. Water content differences have stronger effects than plant functional groups on soil bacteria in a steppe ecosystem.

    Directory of Open Access Journals (Sweden)

    Ximei Zhang

    Full Text Available Many investigations across natural and artificial plant diversity gradients have reported that both soil physicochemical factors and plant community composition affect soil microbial communities. To test the effect of plant diversity loss on soil bacterial communities, we conducted a five-year plant functional group removal experiment in a steppe ecosystem in Inner Mongolia (China. We found that the number and composition type of plant functional groups had no effect on bacterial diversity and community composition, or on the relative abundance of major taxa. In contrast, bacterial community patterns were significantly structured by soil water content differences among plots. Our results support researches that suggest that water availability is the key factor structuring soil bacterial communities in this semi-arid ecosystem.

  14. TBP production plant effluent treatment process

    International Nuclear Information System (INIS)

    Sriniwas, C.; Sugilal, G.; Wattal, P.K.

    2004-06-01

    TBP production facility at Heavy Water Plant, Talcher generates about 2000 litres of effluent per 200 kg batch. The effluent is basically an aqueous solution containing dissolved and dispersed organics such as dibutyl phosphate, butanol etc. The effluent has high salinity, chemical oxygen demand (30-80 g/L) and pungent odour. It requires treatment before discharge. A chemical precipitation process using ferric chloride was developed for quantitative separation of organics from the aqueous part of the effluent. This process facilitates the discharge of the aqueous effluent. Results of the laboratory and bench scale experiments on actual effluent samples are presented in this report. (author)

  15. Collaborative Development Planning Model of Supporting Product in Platform Innovation Ecosystem

    OpenAIRE

    Wei Zhang; Hamid Reza Karimi; Qingpu Zhang; Shaobo Wu

    2014-01-01

    Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://10.1155/2014/690589 In order to improve the market value of the product, the platform enterprise often participates in the development process of supporting product of emerging industry's platform innovation ecosystem. This paper puts forward a revenue sharing contract between the platform company and the supporting company by creating a collaborative developme...

  16. Annual Net Ecosystem Productivity of Wetlands: A Comparison of Automated and Manual Chamber Methods

    Science.gov (United States)

    Burrows, E. H.; Bubier, J. L.; Mosedale, A.; Crill, P. M.

    2001-05-01

    Net Ecosystem Exchange (NEE) of carbon dioxide (CO2) was measured in a minerotrophic poor fen in southeastern New Hampshire during the 2000 growing season using two types of chamber methods. Instantaneous CO2 flux was measured with transparent lexan and teflon static climate controlled chambers by calculating the change in headspace CO2 concentration in the chamber over time. Once per week the flux was sampled from ten manually operated chambers using a LI-COR 6200 portable photosynthesis system, which included a LI-6250 infrared gas analyzer, connected to the chambers. Ten automated chambers were installed in May of 2000, sampling CO2 flux every three hours over the diurnal cycle using a LI-COR 6262 infrared gas analyzer. The chambers and collars were placed throughout the fen in order to sample the range of plant communities. The manual sampling was done during the middle of the day, but the rate of photosynthesis changes depending on the amount of photosynthetically active radiation (PAR). In order to simulate varying light levels, shrouds blocking different amounts of light were placed over each manual chamber. An opaque shroud was used to measure respiration. NEE ranged from -13.0 to 12.5 μ mol CO2/m2/s in the manual chambers and -16.2 to 11.8 μ mol CO2/m2/s in the automated chambers for the mid-summer growing season. Manual respiration fluxes were measured under higher temperature regimes and the response of respiration to temperature will be factored in when comparing the two chamber techniques. Research during the summer of 2001 will also include diurnal measurements. Growing season net ecosystem productivity (NEP) will be estimated and compared for the two chamber systems. Several models will be used to estimate the flux when the manual chambers were not being sampled. The models will be based on biomass and dominant species in each chamber, and various environmental factors including water table, pH, relative humidity, PAR, air and peat temperature

  17. A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

    Science.gov (United States)

    van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

    2008-12-01

    This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

  18. Interactive effects among ecosystem services and management practices on crop production: pollination in coffee agroforestry systems.

    Science.gov (United States)

    Boreux, Virginie; Kushalappa, Cheppudira G; Vaast, Philippe; Ghazoul, Jaboury

    2013-05-21

    Crop productivity is improved by ecosystem services, including pollination, but this should be set in the context of trade-offs among multiple management practices. We investigated the impact of pollination services on coffee production, considering variation in fertilization, irrigation, shade cover, and environmental variables such as rainfall (which stimulates coffee flowering across all plantations), soil pH, and nitrogen availability. After accounting for management interventions, bee abundance improved coffee production (number of berries harvested). Some management interventions, such as irrigation, used once to trigger asynchronous flowering, dramatically increased bee abundance at coffee trees. Others, such as the extent and type of tree cover, revealed interacting effects on pollination and, ultimately, crop production. The effects of management interventions, notably irrigation and addition of lime, had, however, far more substantial positive effects on coffee production than tree cover. These results suggest that pollination services matter, but managing the asynchrony of flowering was a more effective tool for securing good pollination than maintaining high shade tree densities as pollinator habitat. Complex interactions across farm and landscape scales, including both management practices and environmental conditions, shape pollination outcomes. Effective production systems therefore require the integrated consideration of management practices in the context of the surrounding habitat structure. This paper points toward a more strategic use of ecosystem services in agricultural systems, where ecosystem services are shaped by the coupling of management interventions and environmental variables.

  19. Reactor plant construction productivity, why so different

    International Nuclear Information System (INIS)

    Palmeter, S.B.

    1976-01-01

    The manual labor component (manhours per kw) required to construct a nuclear power plant has increased radically since the advent of the fixed price turnkey projects of the late 1960's and early 1970's. Utilities and their architect-engineers have been, for the past several years, evaluating and diagnosing possible reasons for the increase and, in particular, the wide variation in labor manhours per kw among plants built in the same time frame. Since construction labor can amount to as much as 35--40% of direct capital cost, ways and means must be found to arrest this manhour escalation. One important way is by improving productivity. Some of the manhour increase is beyond an owner's control, e.g. NRC regulatory and other federal and state requirements adding to the scope of work. Several areas where there is potential for productivity improvement are identified as follows: (1) Revise contract strategy and bid work on a fixed price basis. This can be done by utilizing bid packages where the scope of work is clearly identified and based on well defined plans and specifications. (2) Upgrade the quality of construction management and remove first line supervision from union control. Use periodic work sampling to pinpoint causes and cure for poor productivity. (3) Reduce design complexity and improve constructibility by means of innovative design and material utilization--models help. (4) Improve labor productivity by restoring management rights in collective bargaining agreements. If this is not possible, go open shop or owner build with your own work force

  20. Diagram for a small planet. The Production and Ecosystem Possibilities Curve

    International Nuclear Information System (INIS)

    Haight, Alan Day

    2007-01-01

    With the development of the GPI there is now an ecological alternative to GDP for measuring a country's economic performance, but we still lack an ecological alternative to the PPC for illustrating a country's economic problem. The diagram suggested here illustrates a country's production and ecosystem possibilities - including climate stability, flood control, carbon sequestration, aquifer recharge, scenery, recreation, biological diversity, and so on. Burning a rainforest to clear the land shifts a country's PPC outward, giving the visual impression of an unmitigated improvement; but such development causes a movement along the country's PEPC, as ecosystem services are transformed into GDP. The slope of the PEPC is the marginal rate of transformation, which equals the ratio of the land's marginal marketable product to its marginal ecosystem product. Changes in technology create substitution and income effects that help explain the enclosure movement and the environmental Kuznets curve. Much as employment of the human resource can be restrained to allow more leisure, development of the natural resource can be restrained to preserve more ecosystem services. Commercial lobbying interests and rivalries for positional goods create distortions that move a country along its PEPC to a materialistic misallocation, with too little conservation. An idealistic misallocation is also possible, with too much preservation of the natural environment. Small is beautiful, up to a point, and that is evident in this diagram. Jacob Viner's [Viner, J., 1937. Studies in the Theory of International Trade. Harper and Brothers, New York] analytical objections to the PPC are revived. (author)

  1. Accumulation of heavy metals in an ecosystem influenced by zinc-plant emissions

    Directory of Open Access Journals (Sweden)

    Zuzanna Czuchajowska

    2014-01-01

    Full Text Available Accumulation of Pb, Zn, Cd, Mn, Fe and Mg reaching the selected ecosystem in the dust emitted by a zinc-mill, was estimated in the leaves of Pinus silvestris, Vaccinium myrtillus and Vaccinium vitis-idaea, the main plant components of the system, and in the five upper soil layers. The values of metal concentration were different for the three considered species and showed-for each of them - dependence on the pollution degree of the stand. This regularity concerned Pb, Zn, Cd and Mn but not Fe and Mg. A significant positive correlation exists between the content of Pb, Zn and Cd in the soil and their concentration in leaves, the correlation for Mil is significant but negative. Manganese in leaves proved to be an antagonist in respect to the other metals.

  2. Historical plant cost and annual production expenses for selected electric plants, 1982

    International Nuclear Information System (INIS)

    1984-01-01

    This publication is a composite of the two prior publications, Hydroelectric Plant Construction Cost and Annual Production Expenses and Thermal-Electric Plant Construction Cost and Annual Production Expenses. Beginning in 1979, Thermal-Electric Plant Construction Cost and Annual Production Expenses contained information on both steam-electric and gas-turbine electric plant construction cost and annual production expenses. The summarized historical plant cost described under Historical Plant Cost in this report is the net cumulative-to-date actual outlays or expenditures for land, structures, and equipment to the utility. Historical plant cost is the initial investment in plant (cumulative to the date of initial commercial operation) plus the costs of all additions to the plant, less the value of retirements. Thus, historical plant cost includes expenditures made over several years, as modifications are made to the plant. Power Production Expenses is the reporting year's plant operation and maintenance expenses, including fuel expenses. These expenses do not include annual fixed charges on plant cost (capital costs) such as interest on debt, depreciation or amortization expenses, and taxes. Consequently, total production expenses and the derived unit costs are not the total cost of producing electric power at the various plants. This publication contains data on installed generating capacity, net generation, net capability, historical plant cost, production expenses, fuel consumption, physical and operating plant characteristics, and other relevant statistical information for selected plants

  3. Plants as natural antioxidants for meat products

    Science.gov (United States)

    Tomović, V.; Jokanović, M.; Šojić, B.; Škaljac, S.; Ivić, M.

    2017-09-01

    The meat industry is demanding antioxidants from natural sources to replace synthetic antioxidants because of the negative health consequences or beliefs regarding some synthetic ones. Plants materials provide good alternatives. Spices and herbs, generally used for their flavouring characteristics, can be added to meat products in various forms: whole, ground, or as isolates from their extracts. These natural antioxidants contain some active compounds, which exert antioxidative potential in meat products. This antioxidant activity is most often due to phenolic acids, phenolic diterpenes, flavonoids and volatile oils. Each of these compounds often has strong H-donating activity, thus making them extremely effective antioxidants; some compounds can chelate metals and donate H to oxygen radicals, thus slowing oxidation via two mechanisms. Numerous studies have demonstrated the efficacy of natural antioxidants when used in meat products. Based on this literature review, it can be concluded that natural antioxidants are added to fresh and processed meat and meat products to delay, retard, or prevent lipid oxidation, retard development of off-flavours (rancidity), improve colour stability, improve microbiological quality and extend shelf-life, without any damage to the sensory or nutritional properties.

  4. Interannual variability of plant phenology in tussock tundra: modelling interactions of plant productivity, plant phenology, snowmelt and soil thaw

    NARCIS (Netherlands)

    Wijk, van M.T.; Williams, M.; Laundre, J.A.; Shaver, G.R.

    2003-01-01

    We present a linked model of plant productivity, plant phenology, snowmelt and soil thaw in order to estimate interannual variability of arctic plant phenology and its effects on plant productivity. The model is tested using 8 years of soil temperature data, and three years of bud break data of

  5. Woody plants in agro-ecosystems of semi-arid regions

    NARCIS (Netherlands)

    Breman, H.; Kessler, J.J.

    1995-01-01

    A quantitative analysis of the role of woody plants in semi-arid regions, focusing on the Sahel and Sudan zones in West-Africa, is given for the assessment of their benefits in agro-sylvopastoral land-use systems with productive and sustainability objectives.

  6. Use of Plant Hydraulic Theory to Predict Ecosystem Fluxes Across Mountainous Gradients in Environmental Controls and Insect Disturbances

    Science.gov (United States)

    Ewers, B. E.; Pendall, E.; Reed, D. E.; Barnard, H. R.; Whitehouse, F.; Frank, J. M.; Massman, W. J.; Brooks, P. D.; Biederman, J. A.; Harpold, A. A.; Naithani, K. J.; Mitra, B.; Mackay, D. S.; Norton, U.; Borkhuu, B.

    2011-12-01

    While mountainous areas are critical for providing numerous ecosystem benefits at the regional scale, the strong gradients in environmental controls make predictions difficult. A key part of the problem is quantifying and predicting the feedback between mountain gradients and plant function which then controls ecosystem cycling. The emerging theory of plant hydraulics provides a rigorous yet simple platform from which to generate testable hypotheses and predictions of ecosystem pools and fluxes. Plant hydraulic theory predicts that plant controls over carbon, water, energy and nutrient fluxes can be derived from the limitation of plant water transport from the soil through xylem and out of stomata. In addition, the limit to plant water transport can be predicted by combining plant structure (e.g. xylem diameters or root-to-shoot ratios) and plant function (response of stomatal conductance to vapor pressure deficit or root vulnerability to cavitation). We evaluate the predictions of the plant hydraulic theory by testing it against data from a mountain gradient encompassing sagebrush steppe through subalpine forests (2700 to 3400 m). We further test the theory by predicting the carbon, water and nutrient exchanges from several coniferous trees in the same gradient that are dying from xylem dysfunction caused by blue-stain fungi carried by bark beetles. The common theme of both of these data sets is a change in water limitation caused by either changing precipitation along the mountainous gradient or lack of access to soil water from xylem-occluding fungi. Across all of the data sets which range in scale from individual plants to hillslopes, the data fit the predictions of plant hydraulic theory. Namely, there was a proportional tradeoff between the reference canopy stomatal conductance to water vapor and the sensitivity of that conductance to vapor pressure deficit that quantitatively fits the predictions of plant hydraulic theory. Incorporating this result into

  7. Mortality gradients within and among dominant plant populations as barometers of ecosystem change during extreme drought.

    Science.gov (United States)

    Gitlin, Alicyn R; Sthultz, Christopher M; Bowker, Matthew A; Stumpf, Stacy; Paxton, Kristina L; Kennedy, Karla; Muñoz, Axhel; Bailey, Joseph K; Whitham, Thomas G

    2006-10-01

    Understanding patterns of plant population mortality during extreme weather events is important to conservation planners because the frequency of such events is expected to increase, creating the need to integrate climatic uncertainty into management. Dominant plants provide habitat and ecosystem structure, so changes in their distribution can be expected to have cascading effects on entire communities. Observing areas that respond quickly to climate fluctuations provides foresight into future ecological changes and will help prioritize conservation efforts. We investigated patterns of mortality in six dominant plant species during a drought in the southwestern United States. We quantified population mortality for each species across its regional distribution and tested hypotheses to identify ecological stress gradients for each species. Our results revealed three major patterns: (1) dominant species from diverse habitat types (i.e., riparian, chaparral, and low- to high-elevation forests) exhibited significant mortality, indicating that the effects of drought were widespread; (2) average mortality differed among dominant species (one-seed juniper[Juniperus monosperma (Engelm.) Sarg.] 3.3%; manzanita[Arctostaphylos pungens Kunth], 14.6%; quaking aspen[Populus tremuloides Michx.], 15.4%; ponderosa pine[Pinus ponderosa P. & C. Lawson], 15.9%; Fremont cottonwood[Populus fremontii S. Wats.], 20.7%; and pinyon pine[Pinus edulis Engelm.], 41.4%); (3) all dominant species showed localized patterns of very high mortality (24-100%) consistent with water stress gradients. Land managers should plan for climatic uncertainty by promoting tree recruitment in rare habitat types, alleviating unnatural levels of competition on dominant plants, and conserving sites across water stress gradients. High-stress sites, such as those we examined, have conservation value as barometers of change and because they may harbor genotypes that are adapted to climatic extremes.

  8. Project AProWa: a national view on managing trade-offs between agricultural production and conservation of aquatic ecosystems

    Science.gov (United States)

    Dietzel, Anne; Rahn, Eric; Stamm, Christian

    2014-05-01

    Swiss agriculture is legally committed to fulfill several, partially conflicting goals such as agricultural production on the one hand and the conservation of natural resources on the other hand. In the context of the research project AProWa ("Agricultural Production and Water"), the relationships between the production aspect and the conservation of aquatic ecosystems is analyzed with a holistic approach. Agricultural production and the protection of water resources have high potential for conflicts: Farmers use ground and surface water to irrigate their fields. On the other hand, drainage systems enable the production on otherwise unfavorably wet soils. These in turn often affect ground water recharge and divert precipitation directly into surface waters, which changes their hydrological regime. Typically, drainage systems also elevate the input of nutrients and pesticides into the water bodies. In general, applied fertilizers, plant protection products, veterinary drugs and phytohormones of cultivated plants are introduced into the ground and surface waters through different processes such as drift, leaching, runoff, preferential flow or erosion. They influence the nutrient cycles and ecological health of aquatic systems. The nutrient and pesticide loss processes themselves can be altered by tillage operations and other agricultural practices. Furthermore, the competition for space can lead to additional conflicts between agriculture and the protection of aquatic ecosystems. For example, channelized or otherwise morphologically changed rivers do not have a natural discharge pattern and are often not suitable for the local flora and fauna; but naturally meandering rivers need space that cannot be used for agriculture. In a highly industrialized and densely populated country like Switzerland, all these potential conflicts are of importance. Although it is typically seen as a water-rich country, local and seasonal overexploitation of rivers through water extraction

  9. Whole system analysis of second generation bioenergy production and Ecosystem Services in Europe

    Science.gov (United States)

    Henner, Dagmar; Smith, Pete; Davies, Christian; McNamara, Niall

    2017-04-01

    Bioenergy crops are an important source of renewable energy and are a possible mechanism to mitigate global climate warming, by replacing fossil fuel energy that has higher greenhouse gas emissions. There is, however, uncertainty about the impacts of the growth of bioenergy crops on ecosystem services. This uncertainty is further enhanced by current climate change. It is important to establish how second generation bioenergy crops (Miscanthus, SRC willow and poplar) can contribute by closing the gap between reducing fossil fuel use and increasing the use of other renewable sources in a sustainable way. The project builds on models of energy crop production, biodiversity, soil impacts, greenhouse gas emissions and other ecosystem services, and on work undertaken in the UK on the ETI-funded ELUM project (www.elum.ac.uk). We will present estimated yields for the above named crops in Europe using the ECOSSE, DayCent, SalixFor and MiscanFor models. These yields will be brought into context with a whole system analysis, detailing trade-offs and synergies for land use change, food security, GHG emissions and soil and water security. Methods like water footprint tools, tourism value maps and ecosystem valuation tools and models (e.g. InVest, TEEB database, GREET LCA Model, World Business Council for Sustainable Development corporate ecosystem valuation, Millennium Ecosystem Assessment and the Ecosystem Services Framework) will be used to estimate and visualise the impacts of increased use of second generation bioenergy crops on the above named ecosystem services. The results will be linked to potential yields to generate "inclusion or exclusion areas" in Europe in order to establish suitable areas for bioenergy crop production and the extent of use possible. Policy is an important factor for using second generation bioenergy crops in a sustainable way. We will present how whole system analysis can be used to create scenarios for countries or on a continental scale. As an

  10. Assessment of productivity at four generating plants

    International Nuclear Information System (INIS)

    Saarlas, M.; Nelson, M.

    1976-01-01

    The 1975 FEA study of power plant reliability was undertaken as a first step in improving the productivity of large (larger than 400 MW) generating units by attempting to trace outages to their root causes so that meaningful corrective action can be taken at the root of the problem. Trident Engineering Associates studied the operation, maintenance, management, and manning of two fossil-fueled and two nuclear-fueled units, one each of above average and one below average reliability (high availability and low forced outage rate). It was expected that the differences between a highly reliable unit and a less reliable unit would lead to recommendations which would be useful for improving productivity of units throughout the country. The findings are of two basic types: (1) general concepts covering problem areas, fundamental reasons and immediate symptoms behind the problems, methods used to eliminate or alleviate the problems, and proposed solutions; (2) details which provide statistics that establish the relative lost productivity by fundamental causes. Eight root causes (fundamental reasons for failures or outages) were established into which most failures and outages could be assigned. Twenty nine cause factors (causes of failure) were established which assisted in assigning the failures and outages to a root cause

  11. Collaborative Development Planning Model of Supporting Product in Platform Innovation Ecosystem

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2014-01-01

    Full Text Available In order to improve the market value of the product, the platform enterprise often participates in the development process of supporting product of emerging industry’s platform innovation ecosystem. This paper puts forward a revenue sharing contract between the platform company and the supporting company by creating a collaborative development model of the supporting product in the ecosystem, and this paper studies the platform enterprise investment resource property's (complementary or substitution impact on the supporting enterprise R&D efforts and the revenue sharing factor and analyzes collaborative development mechanism of supporting product of emerging industry platform innovation ecosystem. The research indicates that when platform enterprise and supporting enterprise's resources are complementary, the supporting enterprise R&D effort level and revenue sharing coefficient increase as the platform company’s investment increases. When platform enterprise and supporting enterprise's resources are substitutive, the supporting enterprise’s R&D effort level and revenue sharing coefficient decrease as the platform company’s investment increases.

  12. Radioactive characterization of the terrestrial ecosystem in the area of location of the Juragua Nuclear Power Plant

    International Nuclear Information System (INIS)

    Sibello Hernandez, R.Y.; Alonso Hernandez, C.M.; Diaz Asencio, M.; Cartas Aguila, H. A.

    1999-01-01

    In this work the results are exposed obtained by the Laboratory of Environmental Surveillance in the radioactive characterization of the existent terrestrial ecosystem in the area of location of the Juragua Nuclear Power Plants in Cienfuegos, Cuba, starting from 1986 and up to 1993

  13. Production Planning and Planting Pattern Scheduling Information System for Horticulture

    Science.gov (United States)

    Vitadiar, Tanhella Zein; Farikhin; Surarso, Bayu

    2018-02-01

    This paper present the production of planning and planting pattern scheduling faced by horticulture farmer using two methods. Fuzzy time series method use to predict demand on based on sales amount, while linear programming is used to assist horticulture farmers in making production planning decisions and determining the schedule of cropping patterns in accordance with demand predictions of the fuzzy time series method, variable use in this paper is size of areas, production advantage, amount of seeds and age of the plants. This research result production planning and planting patterns scheduling information system with the output is recommendations planting schedule, harvest schedule and the number of seeds will be plant.

  14. Gene expression profiling--Opening the black box of plant ecosystem responses to global change

    Energy Technology Data Exchange (ETDEWEB)

    Leakey, A.D.B.; Ainsworth, E.A.; Bernard, S.M.; Markelz, R.J.C.; Ort, D.R.; Placella, S.A.P.; Rogers, A.; Smith, M.D.; Sudderth, E.A.; Weston, D.J.; Wullschleger, S.D.; Yuan, S.

    2009-11-01

    The use of genomic techniques to address ecological questions is emerging as the field of genomic ecology. Experimentation under environmentally realistic conditions to investigate the molecular response of plants to meaningful changes in growth conditions and ecological interactions is the defining feature of genomic ecology. Since the impact of global change factors on plant performance are mediated by direct effects at the molecular, biochemical and physiological scales, gene expression analysis promises important advances in understanding factors that have previously been consigned to the 'black box' of unknown mechanism. Various tools and approaches are available for assessing gene expression in model and non-model species as part of global change biology studies. Each approach has its own unique advantages and constraints. A first generation of genomic ecology studies in managed ecosystems and mesocosms have provided a testbed for the approach and have begun to reveal how the experimental design and data analysis of gene expression studies can be tailored for use in an ecological context.

  15. Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

    Science.gov (United States)

    Magnússon, B.; Magnússon, S. H.; Ólafsson, E.; Sigurdsson, B. D.

    2014-10-01

    Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca

  16. Quantification and valuation of ecosystem services in diverse production systems for informed decision-making

    DEFF Research Database (Denmark)

    Ghaley, Bhim Bahadur; Vesterdal, Lars; Porter, John Roy

    2014-01-01

    The empirical evidence of decline in ecosystem services (ES) over the last century has reinforced the call for ES quantification, monitoring and valuation. Usually, only provisioning ES are marketable and accounted for, whereas regulating, supporting and cultural ES are typically non-marketable a......The empirical evidence of decline in ecosystem services (ES) over the last century has reinforced the call for ES quantification, monitoring and valuation. Usually, only provisioning ES are marketable and accounted for, whereas regulating, supporting and cultural ES are typically non......-marketable and overlooked in connection with land-use or management decisions. The objective of this study was to quantify and value total ES (marketable and non-marketable) of diverse production systems and management intensities in Denmark to provide a basis for decisions based on economic values. The production systems...

  17. Application of Plants as Bio-markers to Assess Wetland Ecosystem Health

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Kupferschmidt, D.A.; Sharp, K.J.; Benz, M.L.; Kim, S.B.; Shultz, C.; Audette-Stuart, M.; Carr, J.

    2008-01-01

    Exposure of non-human biota to radionuclides or other contaminants depends upon a number of factors, which relate to the distribution of a given contaminant in the environment relative to the utilization of the environment by resident biota. Potential effects to biota following contaminant exposure must then be assessed based on the development of defensible linkages between the probability of exposure and the probability of corresponding effects. In many cases, contaminants, such as radionuclides, can show highly localized distributions in natural systems, covering relatively small spatial extents. Despite this, however, in the case of sedentary organisms, such as plants, it is possible for individuals to live in areas with relatively high contaminant levels throughout their lives. Plants represent integral components of ecosystems due to their capacity to use solar energy to convert CO 2 into digestible organic molecules, due to their position at the base of terrestrial and aquatic food chains, and due to their importance as habitat and refuges for terrestrial and aquatic biota. As a result, the integrity of ecosystems is dependent upon plant health. The objective of this study was to determine whether significant changes in parameters reflecting plant photosynthetic capacity occurred with significant differences in 14 C exposure in a wetland ecosystem. The study was conducted in Duke Swamp, a wetland ecosystem that receives 14 C through groundwater influx. Sampling was conducted at 4 locations with varying 14 C concentrations. These locations were selected based on a detailed survey of the swamp that was conducted in 2001 to evaluate the spatial distribution of 14 C in surface vegetation, relative to concentrations reported in Sphagnum moss and soil in the swamp in the early 1990's. Locations were also selected to assess the impacts of both 14 C exposure and the degree of incident solar radiation on plant photosynthetic parameters. A screening analysis of

  18. Ozone flux over a Norway spruce forest and correlation with net ecosystem production

    Czech Academy of Sciences Publication Activity Database

    Zapletal, M.; Cudlín, Pavel; Chroust, P.; Urban, Otmar; Pokorný, Radek; Edwards, Magda; Czerný, Radek; Janouš, Dalibor; Taufarová, Klára; Večeřa, Zbyněk; Mikuška, Pavel; Paoletti, E.

    2011-01-01

    Roč. 159, č. 5 (2011), s. 1024-1034 ISSN 0269-7491 R&D Projects: GA MŽP SP/1B7/189/07 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z40310501 Keywords : ozone deposition * stomatal conductance * deposition velocity * friction velocity * gradient method * tropospheric ozone * net ecosystem production Subject RIV: EH - Ecology, Behaviour Impact factor: 3.746, year: 2011

  19. Productivity, Disturbance and Ecosystem Size Have No Influence on Food Chain Length in Seasonally Connected Rivers

    OpenAIRE

    Warfe, Danielle M.; Jardine, Timothy D.; Pettit, Neil E.; Hamilton, Stephen K.; Pusey, Bradley J.; Bunn, Stuart E.; Davies, Peter M.; Douglas, Michael M.

    2013-01-01

    The food web is one of the oldest and most central organising concepts in ecology and for decades, food chain length has been hypothesised to be controlled by productivity, disturbance, and/or ecosystem size; each of which may be mediated by the functional trophic role of the top predator. We characterised aquatic food webs using carbon and nitrogen stable isotopes from 66 river and floodplain sites across the wet-dry tropics of northern Australia to determine the relative importance of produ...

  20. Biotechnological applications for rosmarinic acid production in plant ...

    African Journals Online (AJOL)

    Biotechnological applications for rosmarinic acid production in plant. ... rosmarinic acid in medicinal plants, herbs and spices has beneficial and health promoting ... of rosmarinic acid starts with the amino acids phenylalanine and tyrosine.

  1. A cross-scale approach to understand drought-induced variability of sagebrush ecosystem productivity

    Science.gov (United States)

    Assal, T.; Anderson, P. J.

    2016-12-01

    Sagebrush (Artemisia spp.) mortality has recently been reported in the Upper Green River Basin (Wyoming, USA) of the sagebrush steppe of western North America. Numerous causes have been suggested, but recent drought (2012-13) is the likely mechanism of mortality in this water-limited ecosystem which provides critical habitat for many species of wildlife. An understanding of the variability in patterns of productivity with respect to climate is essential to exploit landscape scale remote sensing for detection of subtle changes associated with mortality in this sparse, uniformly vegetated ecosystem. We used the standardized precipitation index to characterize drought conditions and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery (250-m resolution) to characterize broad characteristics of growing season productivity. We calculated per-pixel growing season anomalies over a 16-year period (2000-2015) to identify the spatial and temporal variability in productivity. Metrics derived from Landsat satellite imagery (30-m resolution) were used to further investigate trends within anomalous areas at local scales. We found evidence to support an initial hypothesis that antecedent winter drought was most important in explaining reduced productivity. The results indicate drought effects were inconsistent over space and time. MODIS derived productivity deviated by more than four standard deviations in heavily impacted areas, but was well within the interannual variability in other areas. Growing season anomalies highlighted dramatic declines in productivity during the 2012 and 2013 growing seasons. However, large negative anomalies persisted in other areas during the 2014 growing season, indicating lag effects of drought. We are further investigating if the reduction in productivity is mediated by local biophysical properties. Our analysis identified spatially explicit patterns of ecosystem properties altered by severe drought which are consistent with

  2. Californium production at the transuranium processing plant

    International Nuclear Information System (INIS)

    King, L.J.

    1976-01-01

    The Transuranium Processing Plant (TRU) at ORNL, which is the production, storage, and distribution center for the ERDA heavy element research program, is described. About 0.5 percent of 252 Cf is currently being produced. TRU is a hot-cell, chemical processing facility of advanced design. New concepts have been incorporated into the facility for absolute containment, remote operation, remote equipment installation, and remote maintenance. The facilities include a battery of nine heavily shielded process cells served by master-slave manipulators and eight laboratories, four on each of two floors. Processing includes chemical dissolution of the targets followed by a series of solvent extraction, ion exchange, and precipitation steps to separate and purify the transuranium elements. The transcurium elements Bk, Cf, Es, and Fm are distributed to users. Remote techniques are used to fabricate the Am and Cm into target rods for reirradiation in the HFIR. Californium-252 that is in excess of the needs of the heavy element research program and the Cf sales program is stored at TRU and processed repeatedly to recover the daughter product 248 Cm, which is a highly desirable research material

  3. Technoeconomic study of supercritical biodiesel production plant

    International Nuclear Information System (INIS)

    Marchetti, J.M.; Errazu, A.F.

    2008-01-01

    Over the last years, biodiesel has gained more market due to its benefits and because it appears as the natural substitute for diesel. However, the highest cost of this process is associated with the raw material employed, making it a less competitive and more expensive fuel. Therefore, research is being done in order to use low price raw material, such as acid oils, frying oils or soapstocks. In this work, a biodiesel production plant was developed using supercritical methanol and acid oils as raw materials. This technology was compared with some other alternatives previously described with the aim of making a comparative study, not only on the technical aspects but also on the economic results. A process simulator was employed to produce the conceptual design and simulate each technology. Using these models, it was possible to analyze different scenarios and to evaluate productivity, raw material consumption, economic competitiveness and environmental impacts of each process. Although the supercritical alternative appears as a good technical possibility to produce biodiesel, today, it is not an economic alternative due to its high operating costs

  4. Productivity, disturbance and ecosystem size have no influence on food chain length in seasonally connected rivers.

    Science.gov (United States)

    Warfe, Danielle M; Jardine, Timothy D; Pettit, Neil E; Hamilton, Stephen K; Pusey, Bradley J; Bunn, Stuart E; Davies, Peter M; Douglas, Michael M

    2013-01-01

    The food web is one of the oldest and most central organising concepts in ecology and for decades, food chain length has been hypothesised to be controlled by productivity, disturbance, and/or ecosystem size; each of which may be mediated by the functional trophic role of the top predator. We characterised aquatic food webs using carbon and nitrogen stable isotopes from 66 river and floodplain sites across the wet-dry tropics of northern Australia to determine the relative importance of productivity (indicated by nutrient concentrations), disturbance (indicated by hydrological isolation) and ecosystem size, and how they may be affected by food web architecture. We show that variation in food chain length was unrelated to these classic environmental determinants, and unrelated to the trophic role of the top predator. This finding is a striking exception to the literature and is the first published example of food chain length being unaffected by any of these determinants. We suggest the distinctive seasonal hydrology of northern Australia allows the movement of fish predators, linking isolated food webs and potentially creating a regional food web that overrides local effects of productivity, disturbance and ecosystem size. This finding supports ecological theory suggesting that mobile consumers promote more stable food webs. It also illustrates how food webs, and energy transfer, may function in the absence of the human modifications to landscape hydrological connectivity that are ubiquitous in more populated regions.

  5. Ozone flux over a Norway spruce forest and correlation with net ecosystem production

    International Nuclear Information System (INIS)

    Zapletal, Milos; Cudlin, Pavel; Chroust, Petr; Urban, Otmar; Pokorny, Radek; Edwards-Jonasova, Magda; Czerny, Radek; Janous, Dalibor; Taufarova, Klara; Vecera, Zbynek; Mikuska, Pavel; Paoletti, Elena

    2011-01-01

    Daily ozone deposition flux to a Norway spruce forest in Czech Republic was measured using the gradient method in July and August 2008. Results were in good agreement with a deposition flux model. The mean daily stomatal uptake of ozone was around 47% of total deposition. Average deposition velocity was 0.39 cm s -1 and 0.36 cm s -1 by the gradient method and the deposition model, respectively. Measured and modelled non-stomatal uptake was around 0.2 cm s -1 . In addition, net ecosystem production (NEP) was measured by using Eddy Covariance and correlations with O 3 concentrations at 15 m a.g.l., total deposition and stomatal uptake were tested. Total deposition and stomatal uptake of ozone significantly decreased NEP, especially by high intensities of solar radiation. - Highlights: → We estimate ozone deposition flux to a Norway spruce forest using the gradient method and model. → The mean stomatal uptake of ozone is approximately 47% of the total deposition. → We measure net ecosystem production (NEP) using Eddy Covariance. → We test whether elevated total deposition and stomatal uptake of O 3 imply a reduction of NEP. → Deposition and stomatal uptake of O 3 decrease NEP, especially by high intensities of solar radiation. - Net ecosystem production of a Norway spruce forest decreases with increasing deposition and stomatal uptake of ozone.

  6. Linkages Among Water Vapor Flows, Food Production, and Terrestrial Ecosystem Services

    Directory of Open Access Journals (Sweden)

    Johan Rockström

    1999-12-01

    Full Text Available Global freshwater assessments have not addressed the linkages among water vapor flows, agricultural food production, and terrestrial ecosystem services. We perform the first bottom-up estimate of continental water vapor flows, subdivided into the major terrestrial biomes, and arrive at a total continental water vapor flow of 70,000 km3/yr (ranging from 56,000 to 84,000 km3/yr. Of this flow, 90% is attributed to forests, including woodlands (40,000 km3/yr, wetlands (1400 km3/yr, grasslands (15,100 km3/yr, and croplands (6800 km3/yr. These terrestrial biomes sustain society with essential welfare-supporting ecosystem services, including food production. By analyzing the freshwater requirements of an increasing demand for food in the year 2025, we discover a critical trade-off between flows of water vapor for food production and for other welfare-supporting ecosystem services. To reduce the risk of unintentional welfare losses, this trade-off must become embedded in intentional ecohydrological landscape management.

  7. Productivity, disturbance and ecosystem size have no influence on food chain length in seasonally connected rivers.

    Directory of Open Access Journals (Sweden)

    Danielle M Warfe

    Full Text Available The food web is one of the oldest and most central organising concepts in ecology and for decades, food chain length has been hypothesised to be controlled by productivity, disturbance, and/or ecosystem size; each of which may be mediated by the functional trophic role of the top predator. We characterised aquatic food webs using carbon and nitrogen stable isotopes from 66 river and floodplain sites across the wet-dry tropics of northern Australia to determine the relative importance of productivity (indicated by nutrient concentrations, disturbance (indicated by hydrological isolation and ecosystem size, and how they may be affected by food web architecture. We show that variation in food chain length was unrelated to these classic environmental determinants, and unrelated to the trophic role of the top predator. This finding is a striking exception to the literature and is the first published example of food chain length being unaffected by any of these determinants. We suggest the distinctive seasonal hydrology of northern Australia allows the movement of fish predators, linking isolated food webs and potentially creating a regional food web that overrides local effects of productivity, disturbance and ecosystem size. This finding supports ecological theory suggesting that mobile consumers promote more stable food webs. It also illustrates how food webs, and energy transfer, may function in the absence of the human modifications to landscape hydrological connectivity that are ubiquitous in more populated regions.

  8. Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

    Science.gov (United States)

    Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

    2013-01-01

    The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

  9. Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

    Directory of Open Access Journals (Sweden)

    Dongsheng Zhao

    Full Text Available The impact of regional climate change on net primary productivity (NPP is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN, a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

  10. Managing Bioenergy Production on Arable Field Margins for Multiple Ecosystem Services: Challenges and Opportunities

    Science.gov (United States)

    Ferrarini, Andrea; Serra, Paolo; Amaducci, Stefano; Trevisan, Marco; Puglisi, Edoardo

    2013-04-01

    Growing crops for bioenergy is increasingly viewed as conflicting with food production. However, energy use continues to rise and food production requires fuel inputs, which have increased with intensification. The debate should shift from "food or fuel" to the more challenging target: how the increasing demand for food and energy can be met in the future, particularly when water and land availability will be limited. As for food crops, also for bioenergy crops it is questioned whether it is preferable to manage cultivation to enhance ecosystem services ("land sharing" strategy) or to grow crops with lower ecosystem services but higher yield, thereby requiring less land to meet bioenergy demand ("land sparing" strategy). Energy crop production systems differ greatly in the supply of ecosystem services. The use of perennial biomass (e.g. Switchgrass, Mischantus, Giant reed) for energy production is considered a promising way to reduce net carbon emissions and mitigate climate change. In addition, regulating and supporting ecosystem services could be provided when specific management of bioenergy crops is implemented. The idea of HEDGE-BIOMASS* project is to convert the arable field margins to bioenergy crop production fostering a win-win strategy at landscape level. Main objective of the project is to improve land management to generate environmental benefits and increase farmer income. The various options available in literature for an improved field boundary management are presented. The positive/unknown/negative effects of growing perennial bioenergy crops on field margins will be discussed relatively to the following soil-related ecosystem services: (I) biodiversity conservation and enhancement, (II) soil nutrient cycling, (III) climate regulation (reduction of GHG emissions and soil carbon sequestration/stabilization, (IV) water regulation (filtering and buffering), (V) erosion regulation, (VI) pollination and pest regulation. From the analysis of available

  11. Mechanistic insights on the responses of plant and ecosystem gas exchange to global environmental change: lessons from Biosphere 2.

    Science.gov (United States)

    Gonzalez-Meler, Miquel A; Rucks, Jessica S; Aubanell, Gerard

    2014-09-01

    Scaling up leaf processes to canopy/ecosystem level fluxes is critical for examining feedbacks between vegetation and climate. Collectively, studies from Biosphere 2 Laboratory have provided important insight of leaf-to-ecosystem investigations of multiple environmental parameters that were not before possible in enclosed or field studies. B2L has been a testing lab for the applicability of new technologies such as spectral approaches to detect spatial and temporal changes in photosynthesis within canopies, or for the development of cavity ring-down isotope applications for ecosystem evapotranspiration. Short and long term changes in atmospheric CO2, drought or temperature allowed for intensive investigation of the interactions between photosynthesis and leaf, soil and ecosystem respiration. Experiments conducted in the rainforest biome have provided some of the most comprehensive dataset to date on the effects of climate change variables on tropical ecosystems. Results from these studies have been later corroborated in natural rainforest ecosystems and have improved the predictive capabilities of models that now show increased resilience of tropics to climate change. Studies of temperature and CO2 effects on ecosystem respiration and its leaf and soil components have helped reconsider the use of simple first-order kinetics for characterizing respiration in models. The B2L also provided opportunities to quantify the rhizosphere priming effect, or establish the relationships between net primary productivity, atmospheric CO2 and isoprene emissions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Studies on the distribution of 2,4 D herbicide in soil-plant ecosystem using isotope tracer techniques

    International Nuclear Information System (INIS)

    Onal, G.

    1986-01-01

    In this study, distribution of 2,4 Diclorophenoxyacetic acid (2,4 D) herbicide in soil-plant ecosystems under greenhouse conditions were investigated by using isotope tracer techniques. For this purpose barley, wheat and oat plants were grown in two different kinds of soil taken from surrounding of Ankara and the distribution of the herbicide between soil and plants were investigated. In the research 14 C-2,40 D was used and the radioactivity was measured in a liquid scintillation counter. (author)

  13. Editorial: from plant biotechnology to bio-based products.

    Science.gov (United States)

    Stöger, Eva

    2013-10-01

    From plant biotechnology to bio-based products - this Special Issue of Biotechnology Journal is dedicated to plant biotechnology and is edited by Prof. Eva Stöger (University of Natural Resources and Life Sciences, Vienna, Austria). The Special Issue covers a wide range of topics in plant biotechnology, including metabolic engineering of biosynthesis pathways in plants; taking advantage of the scalability of the plant system for the production of innovative materials; as well as the regulatory challenges and society acceptance of plant biotechnology. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Point Estimate Transfers in Ecosystem Services Research: Applying Principles from Economics to Improve the Transfer of Ecological Production Estimates

    Science.gov (United States)

    There is increasing demand to describe and account for the benefits that humans derive from ecosystem functions in decision-making. Comprehensive descriptions of these benefits, referred to as ecosystem services (ES), and their production can be limited because there is limited ...

  15. Value Creation, Appropriation, and Product Design Strategies in Technology Ecosystems: Three Essays on the Role of Complementary Technologies

    Science.gov (United States)

    Miller, Cameron Dee

    2017-01-01

    Firms are often embedded in a technology ecosystem comprised of complementary technologies that span multiple product markets. In this dissertation, I examine how complementarity between the firm's technologies influences its strategies to create and appropriate value in the ecosystem. I investigate this overarching question in two contexts:…

  16. Diagram for a small planet. The Production and Ecosystem Possibilities Curve

    Energy Technology Data Exchange (ETDEWEB)

    Haight, Alan Day [Economics Department, SUNY-Cortland, Old Main, Room 136A, Cortland, New York, 13045 (United States)

    2007-10-15

    With the development of the GPI there is now an ecological alternative to GDP for measuring a country's economic performance, but we still lack an ecological alternative to the PPC for illustrating a country's economic problem. The diagram suggested here illustrates a country's production and ecosystem possibilities - including climate stability, flood control, carbon sequestration, aquifer recharge, scenery, recreation, biological diversity, and so on. Burning a rainforest to clear the land shifts a country's PPC outward, giving the visual impression of an unmitigated improvement; but such development causes a movement along the country's PEPC, as ecosystem services are transformed into GDP. The slope of the PEPC is the marginal rate of transformation, which equals the ratio of the land's marginal marketable product to its marginal ecosystem product. Changes in technology create substitution and income effects that help explain the enclosure movement and the environmental Kuznets curve. Much as employment of the human resource can be restrained to allow more leisure, development of the natural resource can be restrained to preserve more ecosystem services. Commercial lobbying interests and rivalries for positional goods create distortions that move a country along its PEPC to a materialistic misallocation, with too little conservation. An idealistic misallocation is also possible, with too much preservation of the natural environment. Small is beautiful, up to a point, and that is evident in this diagram. Jacob Viner's [Viner, J., 1937. Studies in the Theory of International Trade. Harper and Brothers, New York] analytical objections to the PPC are revived. (author)

  17. Monotoring of mangrove ecosystem in relation with exploration and production activities

    Energy Technology Data Exchange (ETDEWEB)

    Alamsyah, C.; Dwistiadi, D.

    1996-11-01

    From Indonesia`s initial 13 million hectares of mangrove forests, presently only 2.6 million hectares remains which must be certainly protected. Mangrove swamps are of considerable ecological importance not only because of their use as spawning and feeding grounds for a many variety of fish and shrimps but also of economical importance and last but not least as coastal protection. In such a sensitive ecosystem, i.e. in the mangrove swamp area of Mahakam Delta in East Kalimantan, Indonesia, TOTAL Indonesie, an affiliate of the French oil company {open_quotes}TOTAL{close_quotes} and one of the production sharing contractors of PERTAMINA, the Indonesian owned state oil company, has undertaken its E&P operations since 1974. Realizing the sensitivity of the mangrove area, TOTAL Indonesie has undertaken continuous monitoring of the environment as part of its Environmental Management System. This monitoring is very important not only to measure the impact to the mangrove ecosystem in particular due to TOTAL Indonesie activities but also as a feed back for the environmental management. Physicochemical and biological aspects of the environment are monitored and various measurements are taken covering: (1) Hydrology and hydrodynamics of the water streams i.e. the water quality, productivity and flow characteristic of the region (2) Sedimentation and biodegradation (3) The influence of accidental and chronic pollution mangrove ecosystem (3) Sensitivity of the mangroves. The above monitoring has led to the conclusion that after more than 20 years of operation, there has significant adverse impact to the mangrove ecosystem by the exploration and production activities of Indonesie.

  18. Biomass Production System (BPS) Plant Growth Unit

    Science.gov (United States)

    Morrow, R. C.; Crabb, T. M.

    The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses it's own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive

  19. Effects of shading on photosynthesis, plant organic nitrogen uptake and root fungal colonization in a subarctic mire ecosystem

    DEFF Research Database (Denmark)

    Olsrud, Hanna Maria Kerstin; Michelsen, Anders

    2009-01-01

    Arctic dwarf shrub ecosystems are predicted to be exposed to lower light intensity in a changing climate where mountain birch forests are expanding. We investigated how shading at 0%, 65%, and 97% affects photosynthesis, organic N uptake, C and N allocation patterns in plants, and root fungal...... ecosystems are capable of taking up organic N as intact glycine both under high irradiance levels and under shaded conditions when photosynthesis is strongly reduced. The allocation of 15N to green leaves of Rubus chamaemorus L. increased with shading, whereas the allocation of 13C to leaves of both...

  20. Comparison of remote sensing and plant trait-based modelling to predict ecosystem services in subalpine grasslands

    Czech Academy of Sciences Publication Activity Database

    Homolová, Lucie; Schaepman, M. E.; Lamarque, L.; Clevers, J.G.P.W.; de Bello, Francesco; Thuiller, W.; Lavorel, S.

    2014-01-01

    Roč. 5, č. 8 (2014), č. článku 100. ISSN 2150-8925 Institutional support: RVO:67179843 ; RVO:67985939 Keywords : land-use change * leaf chlorophyll content * imaging spectroscopy * water-content * aviris data * spectral reflectance * hyperspectral data * species richness * area index * vegetation * aisa * biomass * ecosystem properties * ecosystem services * linear regression * remote sensing * spatial heterogeneity * subalpine grasslands Subject RIV: EH - Ecology, Behaviour; EF - Botanics (BU-J) OBOR OECD: Remote sensing; Plant sciences, botany (BU-J) Impact factor: 2.255, year: 2014

  1. Applying and Individual-Based Model to Simultaneously Evaluate Net Ecosystem Production and Tree Diameter Increment

    Science.gov (United States)

    Fang, F. J.

    2017-12-01

    Reconciling observations at fundamentally different scales is central in understanding the global carbon cycle. This study investigates a model-based melding of forest inventory data, remote-sensing data and micrometeorological-station data ("flux towers" estimating forest heat, CO2 and H2O fluxes). The individual tree-based model FORCCHN was used to evaluate the tree DBH increment and forest carbon fluxes. These are the first simultaneous simulations of the forest carbon budgets from flux towers and individual-tree growth estimates of forest carbon budgets using the continuous forest inventory data — under circumstances in which both predictions can be tested. Along with the global implications of such findings, this also improves the capacity for forest sustainable management and the comprehensive understanding of forest ecosystems. In forest ecology, diameter at breast height (DBH) of a tree significantly determines an individual tree's cross-sectional sapwood area, its biomass and carbon storage. Evaluation the annual DBH increment (ΔDBH) of an individual tree is central to understanding tree growth and forest ecology. Ecosystem Carbon flux is a consequence of key ecosystem processes in the forest-ecosystem carbon cycle, Gross and Net Primary Production (GPP and NPP, respectively) and Net Ecosystem Respiration (NEP). All of these closely relate with tree DBH changes and tree death. Despite advances in evaluating forest carbon fluxes with flux towers and forest inventories for individual tree ΔDBH, few current ecological models can simultaneously quantify and predict the tree ΔDBH and forest carbon flux.

  2. Modelling impacts of second generation bioenergy production on Ecosystem Services in Europe

    Science.gov (United States)

    Henner, D. N.; Smith, P.; Davies, C.; McNamara, N. P.

    2016-12-01

    Bioenergy crops are an important source of renewable energy and likely to play a major role in transitioning to a lower CO2 energy system. There is, however, uncertainty about the impacts of the growth of bioenergy crops on broader sustainability encompassed by ecosystem services, further enhanced by ongoing climate change. The goal of this project is to develop a comprehensive model that covers ecosystem services at a continental scale including biodiversity and pollination, water and air security, erosion control and soil security, GHG emissions, soil C and cultural services like tourism value. The technical distribution potential and likely yield of second generation energy crops, such as Miscanthus, Short Rotation Coppice (SRC; willow and poplar) was modelled using ECOSSE, DayCent, SalixFor and MiscanFor models. In addition, methods like water footprint tools, tourism value maps and ecosystem valuation tools and models are utilised. We will present results for synergies and trade-offs between land use change and ecosystem services, impact on food security and land management. Further, we will show modelled yield maps for different cultivars of Miscanthus, willow and poplar in Europe and constraint/opportunity maps based on projected yield and other factors e.g. total economic value, technical potential, current land use, climate change and trade-offs and synergies. It will be essential to include multiple ecosystem services when assessing the potential for bioenergy production/expansion that does not impact other land uses or provisioning services. Considering that the soil GHG balance is dominated by change in soil organic carbon (SOC) and the difference among Miscanthus and SRC is largely determined by yield, an important target for management of perennial energy crops is to achieve the best possible yield using the most appropriate energy crop and cultivar for the local situation. This research could inform future policy decisions on bioenergy crops in

  3. Trait-based representation of hydrological functional properties of plants in weather and ecosystem models

    Directory of Open Access Journals (Sweden)

    Ashley M. Matheny

    2017-02-01

    Full Text Available Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings were both feasible and functional for early model generations, in light of the pace at which our knowledge of functional ecology, ecosystem demographics, and vegetation-climate feedbacks has advanced and the ever growing demand for enhanced model performance, these groupings have become antiquated and are identified as a key source of model uncertainty. The newest wave of model development is centered on shifting the vegetation paradigm away from plant functional types (PFTs and towards flexible trait-based representations. These models seek to improve errors in ecosystem fluxes that result from information loss due to over-aggregation of dissimilar species into the same functional class. We advocate the importance of the inclusion of plant hydraulic trait representation within the new paradigm through a framework of the whole-plant hydraulic strategy. Plant hydraulic strategy is known to play a critical role in the regulation of stomatal conductance and thus transpiration and latent heat flux. It is typical that coexisting plants employ opposing hydraulic strategies, and therefore have disparate patterns of water acquisition and use. Hydraulic traits are deterministic of drought resilience, response to disturbance, and other demographic processes. The addition of plant hydraulic properties in models may not only improve the simulation of carbon and water fluxes but also vegetation population distributions.

  4. Isotopic tracers for net primary productivity for a terrestrial ecosystem: a case study of the Volta River basin

    International Nuclear Information System (INIS)

    Hayford, E.K.; Odamtten, G.T.; Enu-Kwesi, L.

    2006-01-01

    The coupling effect of vapour release and CO2 uptake during photosynthesis plays an important role in the carbon and hydrologic cycles. The water use efficiency (WUE) for transpiration was used in calculating the net primary productivity (NPP) for terrestrial ecosystem. Three parameters were used in calculating the water and carbon balance of the River Volta watershed. These are 1) stable isotopes of hydrogen and oxygen, 2) long-term data on precipitation and evapotranspiration, and 3) stoichiometric relations of water and carbon. Results indicate that soils in the watershed annually respire 0.199 Pg C, and that the NPP is +0.029 Pg C yr-1. This implies an annual change in CO2 to the atmosphere within the watershed. Annually, River Volta watershed receives about 380 km3 of rainfall; approximately 50 per cent of which is returned to the atmosphere through plant transpiration. Associated with annual transpiration flux is a carbon flux of 0.170 x 1015 g C yr-1 or 428 g C m-2 yr-1 from the terrestrial ecosystem. Modeled estimates of heterotrophic soil respiration exceeds slightly the estimated NPP values, implying that carbon flux to and from the Volta river watershed is close to being in balance. In other words, the watershed releases annually more carbon dioxide to the atmosphere than it takes. Apart from the terrestrial carbon flux, the balance of photosynthesis and respiration in the Volta lake was also examined. The lake was found to release carbon dioxide to the atmosphere although the magnitude of the flux is smaller than that of the terrestrial ecosystem. (au)

  5. Structure of forest ecosystems and leaf area index of wood plants -results of monitoring over the years 1991-1994

    International Nuclear Information System (INIS)

    Oszlanyi, J.

    1995-01-01

    Monitored characteristics and their dynamics over the last four vegetation seasons reveal the following conclusions: 1) Changes of monitored parameters (e.g. the structure of tree and shrub layer, the leaf area index) are slow, drab and insignificant at the permanent monitoring representing a major part of forest ecosystems of the area affected by the Hydroelectric power structures Gabcikovo. Despite the absence of floods, the ground water level is at a sufficient height to contact rhisosphere of wood plants and the recorded changes are in accord with growth regularities. 2) An increase of the ground water level in the upper part of the monitored territory and a partial renaturation of hydropedological conditions led to an improvement of production-ecological parameters of the area. Changes of its structure are of positive tendency, the leaf area index is stabilised at high values and somewhere even increased (in 1994 being by 70-80% higher than in 1991). 3) Localities with a permanent decrease of the ground water level (band along the old river-bed of the Danube, a dry triangle among the old river-bed of the Danube, the inlet canal and the river arm supplied by the intake structure at Dobrohost and other places) were afflicted by negative changes, locally indicating destruction of tree and shrub layers, with the leaf area index significantly reduced by 20-30%. (author). 1 tab., 5 refs [sk

  6. Aromatic plant production on metal contaminated soils

    International Nuclear Information System (INIS)

    Zheljazkov, Valtcho D.; Craker, Lyle E.; Xing Baoshan; Nielsen, Niels E.; Wilcox, Andrew

    2008-01-01

    Field and container experiments were conducted to assess the feasibility of growing aromatic crops in metal contaminated areas and the effect of metals on herbage and oil productivity. The field experiments were conducted in the vicinities of the Non-Ferrous Metals Combine (Zn-Cu smelter) near Plovdiv, Bulgaria using coriander, sage, dill, basil, hyssop, lemon balm, and chamomile grown at various distances from the smelter. Herbage essential oil yields of basil, chamomile, dill, and sage were reduced when they were grown closer to the smelter. Metal removal from the site with the harvestable plant parts was as high as 180 g ha -1 for Cd, 660 g ha -1 for Pb, 180 g ha -1 for Cu, 350 g ha -1 for Mn, and 205 g ha -1 for Zn. Sequential extraction of soil demonstrated that metal fractionation was affected by the distance to the smelter. With decreasing distance to the smelter, the transfer factor (TF) for Cu and Zn decreased but increased for Cd, while the bioavailability factor (BF) for Cd, Pb, Cu, Mn, and Zn decreased. Scanning electron microscopy and X-ray microanalyses of contaminated soil verified that most of the Pb, Cd, Mn, Cu, and Zn were in the form of small (< 1 μm) particles, although there were larger particles (1-5 μm) with high concentrations of individual metals. This study demonstrated that high concentrations of heavy metals in soil or growth medium did not result in metal transfer into the essential oil. Of the tested metals, only Cu at high concentrations may reduce oil content. Our results demonstrated that aromatic crops may not have significant phytoremediation potential, but growth of these crops in metal contaminated agricultural soils is a feasible alternative. Aromatic crops can provide economic return and metal-free final product, the essential oil

  7. Aromatic plant production on metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Zheljazkov, Valtcho D. [Mississippi State, Department of Plant and Soil Sciences and North Mississippi Research and Extension Center, 5421 Highway 145 South, Verona, MS 38879 (United States)], E-mail: vj40@pss.msstate.edu; Craker, Lyle E.; Xing Baoshan [Department of Plant and Soil Sciences, 12 Stockbridge Hall, University of Massachusetts, Amherst, MA 01003 (United States); Nielsen, Niels E. [Plant Nutrition and Soil Fertility Lab, Department of Agricultural Sciences, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK1871, Copenhagen (Denmark); Wilcox, Andrew [Harper Adams University College, Newport, Shropshire, TF10 8NB (United Kingdom)

    2008-06-01

    Field and container experiments were conducted to assess the feasibility of growing aromatic crops in metal contaminated areas and the effect of metals on herbage and oil productivity. The field experiments were conducted in the vicinities of the Non-Ferrous Metals Combine (Zn-Cu smelter) near Plovdiv, Bulgaria using coriander, sage, dill, basil, hyssop, lemon balm, and chamomile grown at various distances from the smelter. Herbage essential oil yields of basil, chamomile, dill, and sage were reduced when they were grown closer to the smelter. Metal removal from the site with the harvestable plant parts was as high as 180 g ha{sup -1} for Cd, 660 g ha{sup -1} for Pb, 180 g ha{sup -1} for Cu, 350 g ha{sup -1} for Mn, and 205 g ha{sup -1} for Zn. Sequential extraction of soil demonstrated that metal fractionation was affected by the distance to the smelter. With decreasing distance to the smelter, the transfer factor (TF) for Cu and Zn decreased but increased for Cd, while the bioavailability factor (BF) for Cd, Pb, Cu, Mn, and Zn decreased. Scanning electron microscopy and X-ray microanalyses of contaminated soil verified that most of the Pb, Cd, Mn, Cu, and Zn were in the form of small (< 1 {mu}m) particles, although there were larger particles (1-5 {mu}m) with high concentrations of individual metals. This study demonstrated that high concentrations of heavy metals in soil or growth medium did not result in metal transfer into the essential oil. Of the tested metals, only Cu at high concentrations may reduce oil content. Our results demonstrated that aromatic crops may not have significant phytoremediation potential, but growth of these crops in metal contaminated agricultural soils is a feasible alternative. Aromatic crops can provide economic return and metal-free final product, the essential oil.

  8. Inferring differential evolutionary processes of plant persistence traits in Northern Hemisphere Mediterranean fire-prone ecosystems

    Science.gov (United States)

    Pausas, J.G.; Keeley, J.E.; Verdu, M.

    2006-01-01

    1 Resprouting capacity (R) and propagule-persistence (P) are traits that are often considered to have evolved where there are predictable crown fires. Because several indicators suggest a stronger selective pressure for such traits in California than in the Mediterranean Basin, we hypothesize that plant species should have evolved to become R+ and P+ more frequently in California than in the Mediterranean Basin. 2 To test this hypothesis we studied the phylogenetic association between R and P states in both California and the Mediterranean Basin using published molecular phylogenies. 3 The results suggest that R and P evolved differently in the two regions. The occurrence of the states differs significantly between regions for trait P, but not for trait R. The different patterns (towards R+ and P+ in California and towards R+ and P- in the Mediterranean Basin) are reflected in the higher abundance and the wider taxonomic distribution of species with both persistence traits (R+P+ species) in California. 4 The differential acquisition of fire persistence mechanisms at the propagule level (P+) supports the idea that fire selective pressures has been higher in California than in the Mediterranean Basin. 5 Our comparative phylogenetic-informed analysis contributes to an understanding of the differential role of the Quaternary climate in determining fire persistence traits in different Mediterranean-type ecosystems and, thus, to the debate on the evolutionary convergence of traits. ?? 2006 British Ecological Society.

  9. Plant-cover influence on the spatial distribution of radiocaesium deposits in forest ecosystems

    International Nuclear Information System (INIS)

    Guillitte, Olivier; Andolina, Jean; Koziol, Michel; Debauche, Antoine

    1990-01-01

    Since the Chernobyl nuclear accident, a major campaign of radioactive deposit measurements has been carried out on forest soils in Belgium and the Grand Duchy of Luxemburg. Three types of forest ecosystems have systematically been taken into account in each region: coniferous forests (mainly spruce stands), deciduous forests (mainly beech stands) and in clearings. Sampling and field measurements have been carried out in different places with regard to the plant cover: near the trunks, under the foliage, in a small gap, on soil with or without herbaceous or moss stratum. The samples have been collected and measured according to the different recognizable soil layers in order to evaluate the vertical deposit distribution. From overall measurements, one may observe a high spatial soil deposit variation which is mainly explained by the nature, structure and age of the forest stands and by the thickness and the nature of holorganic horizons. A particular interest of this study is the identification of the influence of stem flow and impluvium on forest-cover gaps and edges. (author)

  10. How forest management affects ecosystem services, including timber production and economic return

    DEFF Research Database (Denmark)

    Duncker, Philipp S.; Raulund-Rasmussen, Karsten; Gundersen, Per

    2012-01-01

    and services. By use of virtual but realistic datasets, we quantified, for multiple services, the effects of five forest management alternatives that form an intensity gradient. Our virtual forest management units represented Central European forest ecosystems in the submontane vegetation zone under a humid......–temperate climate with acidic soils. In this zone the European beech (Fagus sylvatica L.) is the dominant tree species. In order to assess the effects on ecosystem services, the untouched natural forest reserve served as a reference. Wherever possible, response functions were deduced to couple the various services...... via stand-level data to demonstrate trade-offs between the services. Management units comprised all development phases in the sense of a "normal forest". It was clearly illustrated that maximizing the rates of biomass production and carbon sequestration may conflict with protection of authentic...

  11. Comparisons of diazotrophic communities in native and agricultural desert ecosystems reveal plants as important drivers in diversity.

    Science.gov (United States)

    Köberl, Martina; Erlacher, Armin; Ramadan, Elshahat M; El-Arabi, Tarek F; Müller, Henry; Bragina, Anastasia; Berg, Gabriele

    2016-02-01

    Diazotrophs provide the only biological source of fixed atmospheric nitrogen in the biosphere. Although they are the key player for plant-available nitrogen, less is known about their diversity and potential importance in arid ecosystems. We investigated the nitrogenase gene diversity in native and agricultural desert soil as well as within root-associated microbiota of medicinal plants grown in Egypt through the combination of nifH-specific qPCR, fingerprints, amplicon pyrosequencing and fluorescence in situ hybridization-confocal laser scanning microscopy. Although the diazotrophic microbiota were characterized by generally high abundances and diversity, statistically significant differences were found between both soils, the different microhabitats, and between the investigated plants (Matricaria chamomilla L., Calendula officinalis L. and Solanum distichum Schumach. and Thonn.). We observed a considerable community shift from desert to agriculturally used soil that demonstrated a higher abundance and diversity in the agro-ecosystem. The endorhiza was characterized by lower abundances and only a subset of species when compared to the rhizosphere. While the microbiomes of the Asteraceae were similar and dominated by potential root-nodulating rhizobia acquired primarily from soil, the perennial S. distichum generally formed associations with free-living nitrogen fixers. These results underline the importance of diazotrophs in desert ecosystems and additionally identify plants as important drivers in functional gene pool diversity. © FEMS 2015.

  12. Carbon nanomaterials alter plant physiology and soil bacterial community composition in a rice-soil-bacterial ecosystem.

    Science.gov (United States)

    Hao, Yi; Ma, Chuanxin; Zhang, Zetian; Song, Youhong; Cao, Weidong; Guo, Jing; Zhou, Guopeng; Rui, Yukui; Liu, Liming; Xing, Baoshan

    2018-01-01

    The aim of this study was to compare the toxicity effects of carbon nanomaterials (CNMs), namely fullerene (C 60 ), reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs), on a mini-ecosystem of rice grown in a loamy potted soil. We measured plant physiological and biochemical parameters and examined bacterial community composition in the CNMs-treated plant-soil system. After 30 days of exposure, all the three CNMs negatively affected the shoot height and root length of rice, significantly decreased root cortical cells diameter and resulted in shrinkage and deformation of cells, regardless of exposure doses (50 or 500 mg/kg). Additionally, at the high exposure dose of CNM, the concentrations of four phytohormones, including auxin, indoleacetic acid, brassinosteroid and gibberellin acid 4 in rice roots significantly increased as compared to the control. At the high exposure dose of MWCNTs and C 60 , activities of the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) in roots increased significantly. High-throughput sequencing showed that three typical CNMs had little effect on shifting the predominant soil bacterial species, but the presence of CNMs significantly altered the composition of the bacterial community. Our results indicate that different CNMs indeed resulted in environmental toxicity to rice and soil bacterial community in the rhizosphere and suggest that CNMs themselves and their incorporated products should be reasonably used to control their release/discharge into the environment to prevent their toxic effects on living organisms and the potential risks to food safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. 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.

  14. Non-Native Plant Invasion along Elevation and Canopy Closure Gradients in a Middle Rocky Mountain Ecosystem.

    Directory of Open Access Journals (Sweden)

    Joshua P Averett

    Full Text Available Mountain environments are currently among the ecosystems least invaded by non-native species; however, mountains are increasingly under threat of non-native plant invasion. The slow pace of exotic plant invasions in mountain ecosystems is likely due to a combination of low anthropogenic disturbances, low propagule supply, and extreme/steep environmental gradients. The importance of any one of these factors is debated and likely ecosystem dependent. We evaluated the importance of various correlates of plant invasions in the Wallowa Mountain Range of northeastern Oregon and explored whether non-native species distributions differed from native species along an elevation gradient. Vascular plant communities were sampled in summer 2012 along three mountain roads. Transects (n = 20 were evenly stratified by elevation (~70 m intervals along each road. Vascular plant species abundances and environmental parameters were measured. We used indicator species analysis to identify habitat affinities for non-native species. Plots were ordinated in species space, joint plots and non-parametric multiplicative regression were used to relate species and community variation to environmental variables. Non-native species richness decreased continuously with increasing elevation. In contrast, native species richness displayed a unimodal distribution with maximum richness occurring at mid-elevations. Species composition was strongly related to elevation and canopy openness. Overlays of trait and environmental factors onto non-metric multidimensional ordinations identified the montane-subalpine community transition and over-story canopy closure exceeding 60% as potential barriers to non-native species establishment. Unlike native species, non-native species showed little evidence for high-elevation or closed-canopy specialization. These data suggest that non-native plants currently found in the Wallowa Mountains are dependent on open canopies and disturbance for

  15. Non-Native Plant Invasion along Elevation and Canopy Closure Gradients in a Middle Rocky Mountain Ecosystem.

    Science.gov (United States)

    Averett, Joshua P; McCune, Bruce; Parks, Catherine G; Naylor, Bridgett J; DelCurto, Tim; Mata-González, Ricardo

    2016-01-01

    Mountain environments are currently among the ecosystems least invaded by non-native species; however, mountains are increasingly under threat of non-native plant invasion. The slow pace of exotic plant invasions in mountain ecosystems is likely due to a combination of low anthropogenic disturbances, low propagule supply, and extreme/steep environmental gradients. The importance of any one of these factors is debated and likely ecosystem dependent. We evaluated the importance of various correlates of plant invasions in the Wallowa Mountain Range of northeastern Oregon and explored whether non-native species distributions differed from native species along an elevation gradient. Vascular plant communities were sampled in summer 2012 along three mountain roads. Transects (n = 20) were evenly stratified by elevation (~70 m intervals) along each road. Vascular plant species abundances and environmental parameters were measured. We used indicator species analysis to identify habitat affinities for non-native species. Plots were ordinated in species space, joint plots and non-parametric multiplicative regression were used to relate species and community variation to environmental variables. Non-native species richness decreased continuously with increasing elevation. In contrast, native species richness displayed a unimodal distribution with maximum richness occurring at mid-elevations. Species composition was strongly related to elevation and canopy openness. Overlays of trait and environmental factors onto non-metric multidimensional ordinations identified the montane-subalpine community transition and over-story canopy closure exceeding 60% as potential barriers to non-native species establishment. Unlike native species, non-native species showed little evidence for high-elevation or closed-canopy specialization. These data suggest that non-native plants currently found in the Wallowa Mountains are dependent on open canopies and disturbance for establishment in low

  16. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India

    Energy Technology Data Exchange (ETDEWEB)

    Jha, V.N., E-mail: jhavn1971@gmail.com; Tripathi, R.M., E-mail: tripathirm@yahoo.com; Sethy, N.K., E-mail: sethybarc@rediffmail.com; Sahoo, S.K., E-mail: sksbarc@gmail.com

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r = 0.86, p < 0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r = 0.88, p < 0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p < 0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. - Highlights: • Uranium mill tailings pond. • Jaduguda, India. • Fresh water plants. • Uranium uptake. • Relationship of uranium with stable elements.

  17. Contrasting water use pattern of introduced and native plants in an alpine desert ecosystem, Northeast Qinghai–Tibet Plateau, China

    International Nuclear Information System (INIS)

    Wu, Huawu; Li, Xiao-Yan; Jiang, Zhiyun; Chen, Huiying; Zhang, Cicheng; Xiao, Xiong

    2016-01-01

    Plant water use patterns reflect the complex interactions between different functional types and environmental conditions in water-limited ecosystems. However, the mechanisms underlying the water use patterns of plants in the alpine desert of the Qinghai–Tibet Plateau remain poorly understood. This study investigated seasonal variations in the water sources of herbs (Carex moorcroftii, Astragalus adsurgens) and shrubs (Artemisia oxycephala, Hippophae rhamnoides) using stable oxygen-18 isotope methods. The results indicated that the native herbs (C. moorcroftii, A. adsurgens) and one of the shrubs (A. oxycephala) mainly relied on water from the shallow layer (0–30 cm) throughout the growing season, while the introduced shrub (H. rhamnoides) showed plasticity in switching between water from shallow and deep soil layers depending on soil water availability. All studied plants primarily depended on water from shallow soil layers early in the season. The differences of water use patterns between the introduced and native plants are closely linked with the range of active root zones when competing for water. Our findings will facilitate the mechanistic understanding of plant–soil–water relations in alpine desert ecosystems and provide information for screening introduced species for sand fixation. - Highlights: • Stable oxygen-18 in soil water experienced great evaporation enrichment. • H. rhamnoides experiences a flexible plasticity to switch between shallow and deep soil water. • Native plants mostly relied on shallow and middle soil water. • Water-use patterns by introduced-native plants are controlled by root characteristics.

  18. Crushed stone production plant for NPP building

    International Nuclear Information System (INIS)

    Obolenskij, V.Ya.

    1982-01-01

    The project of the granite-crushed stone quarry - the large modern plant producing building materials, is presented. The quarry is designated for providing NPP and other power objects building with high-strength crushed stone. The plant consists of: quarry; crushing-sorting plant with maintenance objects arranged on its ground; basis and service stores of explosive materials; tail facility and purifying systems; water supply purifying stations; water storage basin. The plant is reserved for 2335 thousand m 3 yearly utoput of crushed stone; the staff consists of 535 persons, the budgeted cost of building is 26.6 million rubles. Physicochemical characteristics of granosyenites of the ''Granitnoye'' deposit - the raw material resource base of the plant and technological scheme of the crushing-sorting plant are given. Planned measures on building organization and recultivation of disturbed grounds are presented

  19. A New Digital Imaging and Analysis System for Plant and Ecosystem Phenological Studies

    Science.gov (United States)

    Ramirez, G.; Ramirez, G. A.; Vargas, S. A., Jr.; Luna, N. R.; Tweedie, C. E.

    2015-12-01

    Over the past decade, environmental scientists have increasingly used low-cost sensors and custom software to gather and analyze environmental data. Included in this trend has been the use of imagery from field-mounted static digital cameras. Published literature has highlighted the challenge scientists have encountered with poor and problematic camera performance and power consumption, limited data download and wireless communication options, general ruggedness of off the shelf camera solutions, and time consuming and hard-to-reproduce digital image analysis options. Data loggers and sensors are typically limited to data storage in situ (requiring manual downloading) and/or expensive data streaming options. Here we highlight the features and functionality of a newly invented camera/data logger system and coupled image analysis software suited to plant and ecosystem phenological studies (patent pending). The camera has resulted from several years of development and prototype testing supported by several grants funded by the US NSF. These inventions have several unique features and functionality and have been field tested in desert, arctic, and tropical rainforest ecosystems. The system can be used to acquire imagery/data from static and mobile platforms. Data is collected, preprocessed, and streamed to the cloud without the need of an external computer and can run for extended time periods. The camera module is capable of acquiring RGB, IR, and thermal (LWIR) data and storing it in a variety of formats including RAW. The system is full customizable with a wide variety of passive and smart sensors. The camera can be triggered by state conditions detected by sensors and/or select time intervals. The device includes USB, Wi-Fi, Bluetooth, serial, GSM, Ethernet, and Iridium connections and can be connected to commercial cloud servers such as Dropbox. The complementary image analysis software is compatible with all popular operating systems. Imagery can be viewed and

  20. Enhancing legume ecosystem services through an understanding of plant-pollinator interplay

    Directory of Open Access Journals (Sweden)

    Maria Jose eSuso

    2016-03-01

    Full Text Available Legumes are bee-pollinated, but to a different extent. The importance of the plant-pollinator interplay (PPI, in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: 1 optimal productivity, based on an efficient use of pollinators, and 2 biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the pest control service and pollinators in legume crops. The final section addresses general approaches to encourage the synergy between food production and pollination services at farmer field level. Two basic approaches are proposed: a Farming with Alternative Pollinators (FAP and b Crop Design System (CDS.

  1. Terrestrial plant methane production and emission

    DEFF Research Database (Denmark)

    Bruhn, Dan; Møller, Ian M.; Mikkelsen, Teis Nørgaard

    2012-01-01

    In this minireview, we evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants and plant. Clearly, despite much uncertainty and skepticism, we conclude that the phenomenon is true. Four stimulating factors have been observed to induce...... aerobic CH4 into a global budget is inadequate. Thus it is too early to draw the line under the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  2. Repression of fungal plant pathogens and fungal-related contaminants: Selected ecosystem services by soil fauna communities in agroecosystems

    Science.gov (United States)

    Meyer-Wolfarth, Friederike; Schrader, Stefan; Oldenburg, Elisabeth; Brunotte, Joachim; Weinert, Joachim

    2017-04-01

    In agroecosystems soil-borne fungal plant diseases are major yield-limiting factors which are difficult to control. Fungal plant pathogens, like Fusarium species, survive as a saprophyte in infected tissue like crop residues and endanger the health of the following crop by increasing the infection risk for specific plant diseases. In infected plant organs, these pathogens are able to produce mycotoxins. Mycotoxins like deoxynivalenol (DON) persist during storage, are heat resistant and of major concern for human and animal health after consumption of contaminated food and feed, respectively. Among fungivorous soil organisms, there are representatives of the soil fauna which are obviously antagonistic to a Fusarium infection and the contamination with mycotoxins. Specific members of the soil macro-, meso-, and microfauna provide a wide range of ecosystem services including the stimulation of decomposition processes which may result in the regulation of plant pathogens and the degradation of environmental contaminants. Investigations under laboratory conditions and in field were conducted to assess the functional linkage between soil faunal communities and plant pathogenic fungi (Fusarium culmorum). The aim was to examine if Fusarium biomass and the content of its mycotoxin DON decrease substantially in the presence of soil fauna (earthworms: Lumbricus terrestris, collembolans: Folsomia candida and nematodes: Aphelenchoides saprophilus) in a commercial cropping system managed with conservation tillage located in Northern Germany. The results of our investigations pointed out that the degradation performance of the introduced soil fauna must be considered as an important contribution to the biodegradation of fungal plant diseases and fungal-related contaminants. Different size classes within functional groups and the traits of keystone species appear to be significant for soil function and the provision of ecosystem services as in particular L. terrestris revealed to

  3. Potential Applications of Gosat Based Carbon Budget Products to Refine Terrestrial Ecosystem Model

    Science.gov (United States)

    Kondo, M.; Ichii, K.

    2011-12-01

    Estimation of carbon exchange in terrestrial ecosystem associates with difficulties due to complex entanglement of physical and biological processes: thus, the net ecosystem productivity (NEP) estimated from simulation often differs among process-based terrestrial ecosystem models. In addition to complexity of the system, validation can only be conducted in a point scale since reliable observation is only available from ground observations. With a lack of large spatial data, extension of model simulation to a global scale results in significant uncertainty in the future carbon balance and climate change. Greenhouse gases Observing SATellite (GOSAT), launched by the Japanese space agency (JAXA) in January, 2009, is the 1st operational satellite promised to deliver the net land-atmosphere carbon budget to the terrestrial biosphere research community. Using that information, the model reproducibility of carbon budget is expected to improve: hence, gives a better estimation of the future climate change. This initial analysis is to seek and evaluate the potential applications of GOSAT observation toward the sophistication of terrestrial ecosystem model. The present study was conducted in two processes: site-based analysis using eddy covariance observation data to assess the potential use of terrestrial carbon fluxes (GPP, RE, and NEP) to refine the model, and extension of the point scale analysis to spatial using Carbon Tracker product as a prototype of GOSAT product. In the first phase of the experiment, it was verified that an optimization routine adapted to a terrestrial model, Biome-BGC, yielded the improved result with respect to eddy covariance observation data from AsiaFlux Network. Spatial data sets used in the second phase were consists of GPP from empirical algorithm (e.g. support vector machine), NEP from Carbon Tracker, and RE from the combination of these. These spatial carbon flux estimations was used to refine the model applying the exactly same

  4. Soil biota suppress positive plant diversity effects on productivity at high but not low soil fertility

    NARCIS (Netherlands)

    Luo, Shan; Deyn, De Gerlinde B.; Jiang, B.; Yu, Shixiao

    2017-01-01

    Plant community productivity commonly increases with increasing plant diversity, which is explained by complementarity among plant species in resource utilization (complementarity effect), or by selection of particularly productive plant species in diverse plant communities (selection effect).

  5. Transgenic plants as green factories for vaccine production | Vinod ...

    African Journals Online (AJOL)

    Edible vaccine technology represents an alternative to fermentation based vaccine production system. Transgenic plants are used for the production of plant derived specific vaccines with native immunogenic properties stimulating both humoral and mucosal immune responses. Keeping in view the practical need of new ...

  6. Context dependency and saturating effects of loss of rare soil microbes on plant productivity

    Directory of Open Access Journals (Sweden)

    Gera eHol

    2015-06-01

    Full Text Available Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing towards a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

  7. Context dependency and saturating effects of loss of rare soil microbes on plant productivity.

    Science.gov (United States)

    Hol, W H Gera; de Boer, Wietse; de Hollander, Mattias; Kuramae, Eiko E; Meisner, Annelein; van der Putten, Wim H

    2015-01-01

    Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition, and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing toward a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

  8. 9 CFR 355.21 - Products entering inspected plants.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION AND CERTIFICATION CERTIFIED PRODUCTS FOR DOGS, CATS, AND OTHER CARNIVORA; INSPECTION... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Products entering inspected plants. 355.21 Section 355.21 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF...

  9. Enhanced ergonomics approaches for product design: a user experience ecosystem perspective and case studies.

    Science.gov (United States)

    Xu, Wei

    2014-01-01

    This paper first discusses the major inefficiencies faced in current human factors and ergonomics (HFE) approaches: (1) delivering an optimal end-to-end user experience (UX) to users of a solution across its solution lifecycle stages; (2) strategically influencing the product business and technology capability roadmaps from a UX perspective and (3) proactively identifying new market opportunities and influencing the platform architecture capabilities on which the UX of end products relies. In response to these challenges, three case studies are presented to demonstrate how enhanced ergonomics design approaches have effectively addressed the challenges faced in current HFE approaches. Then, the enhanced ergonomics design approaches are conceptualised by a user-experience ecosystem (UXE) framework, from a UX ecosystem perspective. Finally, evidence supporting the UXE, the advantage and the formalised process for executing UXE and methodological considerations are discussed. Practitioner Summary: This paper presents enhanced ergonomics approaches to product design via three case studies to effectively address current HFE challenges by leveraging a systematic end-to-end UX approach, UX roadmaps and emerging UX associated with prioritised user needs and usages. Thus, HFE professionals can be more strategic, creative and influential.

  10. Effects of active forest fire on terrestrial ecosystem production and greenhouse gas emissions

    Science.gov (United States)

    Sannigrahi, Srikanta; Rahmat, Shahid; Bhatt, Sandeep; Rana, Virendra

    2017-04-01

    The forest fire is one of the most catalysing agents which degrade an ecosystems leading to the loss of net and gross primary productivity (NPP & GPP) and carbon sequestration service. Additionally, it can suppress the efficiency of service providing capacity of an ecosystem throughout the time and space. Remote sensing-based forest fire estimation in a diverse ecosystem is very much essential for mitigating the biodiversity and productivity losses due to the forest fire. Satellite-based Land Surface Temperature (LST) has been calculated for the pre-fire and fire years to identify the burn severity hotspot across all eco-regions in the Lower Himalaya region. Several burn severity indices: Normalized Burn Ratio (NBR), Burnt Area Index (BAI), Normalized Multiband Drought Index (NMDI), Soil Adjusted Vegetation Index (SAVI), Global Environmental Monitoring Index (GEMI), Enhance Vegetation Index (EVI) have been used in this study to quantify the spatial and temporal changes (delta) of the selected indices. Two Light Use Efficiency (LUE) models: Carnegie- Ames-Stanford-Approach (CASA) and Vegetation Photosynthesis Model (VPM) have been used to quantify the terrestrial Net Primary Productivity (NPP) in the pre-fire and fire years across all biomes of the region. A novel approach has been preceded in this field to demonstrate the correlation between forest fire density (FFD) and NPP. A strong positive correlation was found between burn severity indices and predicted NPP: BAI and NPP (r = 0.49), NBR and NPP: (r = 0.58), EVI and NPP: (r = 0.72), SAVI and NPP: (r = 0.67), whereas, a negative association has noted between the NMDI and NPP: (r = -0.36) during the both studied years. Results have shown that the NPP is highly correlated with the forest fire density (R2 = 0.75, RMSE = 5.03 gC m-2 month-1). The estimated LST of the individual fire days has witnessed a sharp temperature increase by > 6oC - 9oC in comparison to the non-fire days clearly indicates high fire risk (in

  11. Transfer of radionuclides by terrestrial food products from semi-natural ecosystems to humans

    International Nuclear Information System (INIS)

    Howard, B.J.

    1996-01-01

    The potential radiological significance of radionuclide transfer to humans via foodstuffs derived from semi-natural ecosystems has become apparent since the Chernobyl accident. Foodchain models developed before this time usually did not take such transfers into account. The processes leading to contamination of food in these environments are complex and current understanding of the transfer mechanisms is incomplete. For these reasons the approach adopted in Chapter 3 is to represent, by means of aggregated parameters, the empirical relationships between ground deposits and concentration in the food product. 107 refs, 2 figs, 9 tabs

  12. The Transfer and diffusion of Cesium 137 within forest ecosystem in Fukushima after the nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Takahiro; Murakami, Masashi [Community Ecology Lab., Biology Course, Faculty of Science, Chiba University, Chiba, 263-8522 (Japan); Ishii, Nobuyoshi [National Institute of Radiological Sciences, Chiba, 263-8555 (Japan); Tanoi, Keitaro; Hirose, Atsushi; Ohte, Nobuhito [Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 (Japan)

    2014-07-01

    A large amount of radionuclides was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident after the disastrous earthquake and subsequent tsunami of March 2011. Among the variety of radionuclides released from FDNPP, cesium 137 ({sup 137}Cs) is the most worrying radionuclide in the environment, with a half-life of 30 years. Since most of the Japanese land area is covered by forest, the distribution and transportation of radioactive materials within forest ecosystems should be conscientiously monitored. In Europe, many studies reported that the {sup 137}Cs deposition caused by the Chernobyl accident has still been distributed in the litter and soil layers and has become a source for the soil-to-plant transfer. Most of these studies emphasize the 'stability' of {sup 137}Cs within forest ecosystems, because {sup 137}Cs are considered to be strongly and immediately fixed in clay minerals. Even though there are many studies of the soil-to-plant transfer of {sup 137}Cs in forest after several years of Chernobyl accident, very initial distribution and transfer of {sup 137}Cs in food web within one to two years after the deposition in forest ecosystems have never been examined. The evaluation of the initial dynamics of {sup 137}Cs in forest ecosystems should be quite important because of the increasing stability of {sup 137}Cs after the deposition. The accumulation and transfer of {sup 137}Cs through food web within forest ecosystems were examined by collecting various organisms at forests in Fukushima. The {sup 137}Cs concentrations, natural Cs and K concentrations, and delta {sup 15}N of the specimens were measured to evaluate the occurrence of bioaccumulation or bio-diffusion of {sup 137}Cs through tropic interaction within forest ecosystem. {sup 137}Cs was highly concentrated on leaf litters which had been deposited in autumn 2010, before the accident. This accumulated {sup 137}Cs had transferred to higher trophic organisms mainly through

  13. Biotic and abiotic processes in eastside ecosystems: the effects of management on soil properties, processes, and productivity.

    Science.gov (United States)

    Alan E. Harvey; J. Michael Geist; Gerald L McDonald; Martin F. Jurgensen; Patrick H. Cochran; Darlene Zabowski; Robert T. Meurisse

    1994-01-01

    Productivity of forest and range land soils is based on a combination of diverse physical, chemical and biological properties. In ecosystems characteristic of eastside regions of Oregon and Washington, the productive zone is usually in the upper 1 or 2 m. Not only are the biological processes that drive both soil productivity and root development concentrated in...

  14. Aromatic plants play an important role in promoting soil biological activity related to nitrogen cycling in an orchard ecosystem.

    Science.gov (United States)

    Chen, Xinxin; Song, Beizhou; Yao, Yuncong; Wu, Hongying; Hu, Jinghui; Zhao, Lingling

    2014-02-15

    Aromatic plants can substantially improve the diversity and structure of arthropod communities, as well as reduce the number of herbivore pests and regulate the abundance of predators and parasitoids. However, it is not clear whether aromatic plants are also effective in improving soil quality by enhancing nutrient cycling. Here, field experiments are described involving intercropping with aromatic plants to investigate their effect on soil nitrogen (N) cycling in an orchard ecosystem. The results indicate that the soil organic nitrogen and available nitrogen contents increased significantly in soils intercropped with aromatic plants. Similarly, the activities of soil protease and urease increased, together with total microbial biomass involved in N cycling, including nitrifying bacteria, denitrifying bacteria and azotobacters, as well as the total numbers of bacteria and fungi. This suggests that aromatic plants improve soil N cycling and nutrient levels by enriching the soil in organic matter through the regulation of both the abundance and community structure of microorganisms, together with associated soil enzyme activity, in orchard ecosystems. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Nitrogen cycling in a flooded-soil ecosystem planted to rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Reddy, K.R.

    1982-01-01

    15 N studies of various aspects of the nitrogen cycle in a flooded rice ecosystem on Crowley silt loam soil in Louisiana were reviewed to construct a mass balance model of the nitrogen cycle for this system. Nitrogen transformations modeled included 1) net ammonification (0.22 mg NH 4+ -N kg dry soil - 1 day - 1 ). 2) net nitrification (207 mg NO 3- -N kg dry soil - 1 day - 1 ). 3) denitrification (0.37 mg N kg dry soil - 1 day - 1 ), and 4) biological N 2 fixation (0.16 mg N kg dry soil - 1 day - 1 ). Nitrogen inputs included 1) application of fertilizers, 2) incorporation of crop residues, 3) biological N 2 fixation, and 4) deposition. Nitrogen outputs included 1) crop removal, 2) gaseous losses from NH 3 volatilization and simultaneous occurrence of nitrification-denitrification, and 3) leaching and runoff. Mass balance calculations indicated that 33% of the available inorganic nitrogen was recovered by rice, and the remaining nitrogen was lost from the system. Losses of N due to ammonia volatilization were minimal because fertilizer-N was incorporated into the soil. A significant portion of inorganic-N was lost by ammonium diffusion from the anaerobic layer to the aerobic layer in response to a concentration gradient and subsequent nitrification in the aerobic layer followed by nitrate diffusion into the anaerobic layer and denitrification into gaseous end products. Leaching and surface runoff losses were minimal. (orig.)

  16. Robotized production systems observed in modern plants

    Science.gov (United States)

    Saverina, A. N.

    1985-09-01

    Robots, robotized lines and sectors are no longer innovations in shops at automotive plants. The widespread robotization of automobile assembly operations is described in general terms. Robot use for machining operation is also discussed.

  17. Attributing Asymmetric Productivity Responses to Internal Ecosystem Dynamics and External Drivers Using Probabilistic Models

    Science.gov (United States)

    Parolari, A.; Goulden, M.

    2017-12-01

    A major challenge to interpreting asymmetric changes in ecosystem productivity is the attribution of these changes to external climate forcing or to internal ecophysiological processes that respond to these drivers (e.g., photosynthesis response to drying soil). For example, positive asymmetry in productivity can result from either positive skewness in the distribution of annual rainfall amount or from negative curvature in the productivity response to annual rainfall. To analyze the relative influences of climate and ecosystem dynamics on both positive and negative asymmetry in multi-year ANPP experiments, we use a multi-scale coupled ecosystem water-carbon model to interpret field experimental results that span gradients of rainfall skewness and ANPP response curvature. The model integrates rainfall variability, soil moisture dynamics, and net carbon assimilation from the daily to inter-annual scales. From the underlying physical basis of the model, we compute the joint probability distribution of the minimum and maximum ANPP for an annual ANPP experiment of N years. The distribution is used to estimate the likelihood that either positive or negative asymmetry will be observed in an experiment, given the annual rainfall distribution and the ANPP response curve. We estimate the total asymmetry as the mode of this joint distribution and the relative contribution attributable to rainfall skewness as the mode for a linear ANPP response curve. Applied to data from several long-term ANPP experiments, we find that there is a wide range of observed ANPP asymmetry (positive and negative) and a spectrum of contributions from internal and external factors. We identify the soil water holding capacity relative to the mean rain event depth as a critical ecosystem characteristic that controls the non-linearity of the ANPP response and positive curvature at high rainfall. Further, the seasonal distribution of rainfall is shown to control the presence or absence of negative

  18. Plant Design for the Production of DUAGG

    International Nuclear Information System (INIS)

    Ferrada, J.J.

    2003-01-01

    The cost of producing DUAGG is an important consideration for any interested private firm in determining whether DUCRETE is economically viable as a material of construction in next-generation spent nuclear fuel casks. This study analyzed this project as if it was a stand-alone project. The capital cost includes engineering design, equipment costs and installation, start up, and management; the study is not intended to be a life-cycle cost analysis. The costs estimated by this study are shown in Table ES.1, and the conclusions of this study are listed in Table ES.2. The development of DUAGG and DUCRETE is a major thrust of the Depleted Uranium Uses Research and Development Project. An obvious use of depleted uranium is as a shielding material (e.g., DUCRETE). DUCRETE is made by replacing the conventional stone aggregate in concrete with DUAGG. One objective of this project is to bring the development of DUCRETE to a point at which a demonstrated basis exists for its commercial deployment. The estimation of the costs to manufacture DUAGG is an important part of this effort. Paul Lessing and William Quapp developed DUAGG and DUCRETE as part of an Idaho National Engineering and Environmental Laboratory (INEEL) program to find beneficial uses for depleted uranium (DU). Subsequently, this technology was licensed to Teton Technologies, Inc. The DUAGG process mixes DUO 2 with sintering materials and additives to form pressed briquettes. These briquettes are sintered at 1300 C, and the very dense sintered briquettes are then crushed and classified into gap-graded size fractions. The graded DUAGG is then ready to be used to make high-strength heavy DUCRETE. The DUCRETE shielding will be placed into an annular steel cask-shell mold, which has internal steel reinforcing bars. The objectives of this study are to (1) use previous DUAGG process developments to design a plant that will produce DUAGG at a baseline rate, (2) determine the size of the equipment required to meet the

  19. Valuing multiple eelgrass ecosystem services in Sweden: fish production and uptake of carbon and nitrogen

    Directory of Open Access Journals (Sweden)

    Scott Glenn Cole

    2016-01-01

    Full Text Available Valuing nature’s benefits in monetary terms is necessary for policy-makers facing trade-offs in how to spend limited financial resources on environmental protection. We provide information to assess trade-offs associated with the management of seagrass beds, which provide a number of ecosystem services, but are presently impacted by many stressors. We develop an interdisciplinary framework for valuing multiple ecosystem services and apply it to the case of eelgrass (Zostera marina, a dominant seagrass species in the northern hemisphere. We identify and quantify links between three eelgrass functions (habitat for fish, carbon and nitrogen uptake and economic goods in Sweden, quantify these using ecological endpoints, estimate the marginal average value of the impact of losing one hectare of eelgrass along the Swedish northwest coast on welfare in monetary terms, and aggregate these values while considering double-counting. Over a 20 to 50 year period we find that compared to unvegetated habitats, a hectare of eelgrass, including the organic material accumulated in the sediment, produces an additional 626 kg cod fishes and 7,535 wrasse individuals and sequesters 98.6 ton carbon and 466 kg nitrogen. We value the flow of future benefits associated with commercial fishing, avoided climate change damages, and reduced eutrophication at 170,000 SEK in 2014 (20,700 US$ or 11,000 SEK (1,300 US$ annualized at 4%. Fish production, which is the most commonly valued ecosystem service in the seagrass literature, only represented 25% of the total value whereas a conservative estimate of nitrogen regulation constituted 46%, suggesting that most seagrass beds are undervalued. Comparing these values with historic losses of eelgrass we show that the Swedish northwest coast has suffered a substantial reduction in fish production and mineral regulation. Future work should improve the understanding of the geographic scale of eelgrass functions, how local variables

  20. The invasive alien plants threatened the balance of ecosystem in conservative area in Ontoloe Island, Flores-Indonesia

    Science.gov (United States)

    Antonius Mboka Segu Wake, Ignatius; Retnaningsih Soeprobowati, Tri; Jumari

    2018-05-01

    Invasive alien plants threaten to biodiversity, particularly in small island with high endemicity values such as Ontoloe Island, a tourist destination area of Riung Seventeen Island in Flores. The study aims to characterized the invasive plants have attacked the conservative area in Ontoloe Island. The method used by combining the line method and the plot method with three observation stations in utilization block and four observation station in protection block. Plot of 1mx1m was used for the observation of ground cover plants and seedling, 5mx5m for the observation in stake level, 10mx10m for the observation in pole level, 20mx20m for the observation in tree level. The data level of the plants obtained then analyzed with Important Value Index (IVI). Result showed that Lamtoro plants (Leuchaena leucocephala) is the invasive alien species which has the highest IVI in both of utilization block and protection block in each level of tree, stake, and pole. There are other invasive alien plants such as Tembeleken (Lantana camara) and Bidara (Zizipus mauritiana) dominated in stake level and Alang-alang (Imperata cylindrica) dominated in seedling level. All the native plants in Ontoloe Island will be threatened their existing because of the less control of invasive alien plants. Therefore, needs serious handling by the government in order to keep the balanced of the ecosystems in Ontoloe Island to be maintained especially to not deviated from management objectives area of Komodo Dragons conservation (Varanus komodoensis Ouwens, 1912).

  1. Seasonal and interannual patterns in primary production, respiration and net ecosystem metabolism in three estuaries in the northeast Gulf of Mexico

    Science.gov (United States)

    Measurements of primary production and respiration provide fundamental information about the trophic status of aquatic ecosystems, yet such measurements are logistically difficult and expensive to sustain as part of long-term monitoring programs. However, ecosystem metabolism par...

  2. The impact of new product introduction on plant productivity in the North American automotive industry

    NARCIS (Netherlands)

    Gopal, A.; Goyal, M.; Netessine, S.; Reindorp, M.J.

    2013-01-01

    Product launch—an event when a new product debuts for production in a plant—is an important phase in product development. But launches disrupt manufacturing operations, resulting in productivity losses. Using data from North American automotive plants from years 1999–2007, we estimate that a product

  3. Ecosystem carbon partitioning: aboveground net primary productivity correlates with the root carbon input in different land use types of Southern Alps

    Science.gov (United States)

    Rodeghiero, Mirco; Martinez, Cristina; Gianelle, Damiano; Camin, Federica; Zanotelli, Damiano; Magnani, Federico

    2013-04-01

    Terrestrial plant carbon partitioning to above- and below-ground compartments can be better understood by integrating studies on biomass allocation and estimates of root carbon input based on the use of stable isotopes. These experiments are essential to model ecosystem's metabolism and predict the effects of global change on carbon cycling. Using in-growth soil cores in conjunction with the 13C natural abundance method we quantified net plant-derived root carbon input into the soil, which has been pointed out as the main unaccounted NPP (net primary productivity) component. Four land use types located in the Trentino Region (northern Italy) and representing a range of aboveground net primary productivity (ANPP) values (155-868 gC m-2 y-1) were investigated: conifer forest, apple orchard, vineyard and grassland. Cores, filled with soil of a known C4 isotopic signature were inserted at 18 sampling points for each site and left in place for twelve months. After extraction, cores were analysed for %C and d13C, which were used to calculate the proportion of new plant-derived root C input by applying a mass balance equation. The GPP (gross primary productivity) of each ecosystem was determined by the eddy covariance technique whereas ANPP was quantified with a repeated inventory approach. We found a strong and significant relationship (R2 = 0.93; p=0.03) between ANPP and the fraction of GPP transferred to the soil as root C input across the investigated sites. This percentage varied between 10 and 25% of GPP with the grassland having the lowest value and the apple orchard the highest. Mechanistic ecosystem carbon balance models could benefit from this general relationship since ANPP is routinely and easily measured at many sites. This result also suggests that by quantifying site-specific ANPP, root carbon input can be reliably estimated, as opposed to using arbitrary root/shoot ratios which may under- or over-estimate C partitioning.

  4. Special forest products: integrating social, economic, and biological considerations into ecosystem management.

    Science.gov (United States)

    R. Molina; N. Vance; J.F. Weigand; D. Pilz; M.P. Amaranthus

    1997-01-01

    Throughout history, forests have provided a wealth of beneficial and essential products ranging from foods and medicines to building materials. Ancient pharmacopoeias list myriad forest plants and fungi for treating various ailments. Many of these ancient remedies have evolved and continue to evolve into the important drugs of modern medicine. Use of diverse forest...

  5. Potential consequences of climate change for primary production and fish production in large marine ecosystems.

    Science.gov (United States)

    Blanchard, Julia L; Jennings, Simon; Holmes, Robert; Harle, James; Merino, Gorka; Allen, J Icarus; Holt, Jason; Dulvy, Nicholas K; Barange, Manuel

    2012-11-05

    Existing methods to predict the effects of climate change on the biomass and production of marine communities are predicated on modelling the interactions and dynamics of individual species, a very challenging approach when interactions and distributions are changing and little is known about the ecological mechanisms driving the responses of many species. An informative parallel approach is to develop size-based methods. These capture the properties of food webs that describe energy flux and production at a particular size, independent of species' ecology. We couple a physical-biogeochemical model with a dynamic, size-based food web model to predict the future effects of climate change on fish biomass and production in 11 large regional shelf seas, with and without fishing effects. Changes in potential fish production are shown to most strongly mirror changes in phytoplankton production. We project declines of 30-60% in potential fish production across some important areas of tropical shelf and upwelling seas, most notably in the eastern Indo-Pacific, the northern Humboldt and the North Canary Current. Conversely, in some areas of the high latitude shelf seas, the production of pelagic predators was projected to increase by 28-89%.

  6. Optimized estimation and its uncertainties of gross primary production over oasis-desert ecosystems in an arid region of China

    Science.gov (United States)

    Wang, H.; Li, X.; Xiao, J.; Ma, M.

    2017-12-01

    Arid and semi-arid ecosystems cover more than one-third of the Earth's land surface, it is of great important to the global carbon cycle. However, the magnitude of carbon sequestration and its contribution to global atmospheric carbon cycle is poorly understood due to the worldwide paucity of measurements of carbon exchange in the arid ecosystems. Accurate and continuous monitoring the production of arid ecosystem is of great importance for regional carbon cycle estimation. The MOD17A2 product provides high frequency observations of terrestrial Gross Primary Productivity (GPP) over the world. Although there have been plenty of studies to validate the MODIS GPP products with ground based measurements over a range of biome types, few have comprehensively validated the performance of MODIS estimates in arid and semi-arid ecosystems. Thus, this study examined the performance of the MODIS-derived GPP comparing with the EC observed GPP at different timescales for the main arid ecosystems in the arid and semi-arid ecosystems in China, and optimized the performance of the MODIS GPP calculations by using the in-situ metrological forcing data, and optimization of biome-specific parameters with the Bayesian approach. Our result revealed that the MOD17 algorithm could capture the broad trends of GPP at 8-day time scales for all investigated sites on the whole. However, the GPP product was underestimated in most ecosystems in the arid region, especially the irrigated cropland and forest ecosystems, while the desert ecosystem was overestimated in the arid region. On the annual time scale, the best performance was observed in grassland and cropland, followed by forest and desert ecosystems. On the 8-day timescale, the RMSE between MOD17 products and in-situ flux observations of all sites was 2.22 gC/m2/d, and R2 was 0.69. By using the in-situ metrological data driven, optimizing the biome-based parameters of the algorithm, we improved the performances of the MODIS GPP calculation

  7. Relationship between stoichiometry and ecosystem services in organic crop production systems

    DEFF Research Database (Denmark)

    Fan, Fan

    contribute to and mitigate global ES loss. Organic farming has been suggested as one possible solution to alleviate the loss of ES in agro-ecosystems due to its environmental benefits compared with conventional farming. However, only a few studies have accounted for the economic value of ES in different...... organic crop production systems and little is known about how anthropogenic activities affect the supply of ES in such organic crop production systems. Ecological stoichiometry, which is the study of the fluxes of chemical elements and the ratio between them, has been considered as a new approach....... The organic farming systems with a high soil C:N stoichiometric ratio had a potential to produce more food, sequester more carbon from the atmosphere, store more water in the soil, attract more aphid predators, and regulate more nitrogen compared with the organic farming systems with a low soil C...

  8. Ecosystem Development after Mangrove Wetland Creation: Plant-Soil Change across a 20-year Chronosequence

    Science.gov (United States)

    Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland loss. However, ecosystem development and functional equivalence in restored and created mangrove wetlands is poorly understood. We compared a 20-yr chrono...

  9. Plant trait-based models identify direct and indirect effects of climate change on bundles of grassland ecosystem services.

    Science.gov (United States)

    Lamarque, Pénélope; Lavorel, Sandra; Mouchet, Maud; Quétier, Fabien

    2014-09-23

    Land use and climate change are primary causes of changes in the supply of ecosystem services (ESs). Although the consequences of climate change on ecosystem properties and associated services are well documented, the cascading impacts of climate change on ESs through changes in land use are largely overlooked. We present a trait-based framework based on an empirical model to elucidate how climate change affects tradeoffs among ESs. Using alternative scenarios for mountain grasslands, we predicted how direct effects of climate change on ecosystems and indirect effects through farmers' adaptations are likely to affect ES bundles through changes in plant functional properties. ES supply was overall more sensitive to climate than to induced management change, and ES bundles remained stable across scenarios. These responses largely reflected the restricted extent of management change in this constrained system, which was incorporated when scaling up plot level climate and management effects on ecosystem properties to the entire landscape. The trait-based approach revealed how the combination of common driving traits and common responses to changed fertility determined interactions and tradeoffs among ESs.

  10. Looking Past Primary Productivity: Benchmarking System Processes that Drive Ecosystem Level Responses in Models

    Science.gov (United States)

    Cowdery, E.; Dietze, M.

    2017-12-01

    As atmospheric levels of carbon dioxide levels continue to increase, it is critical that terrestrial ecosystem models can accurately predict ecological responses to the changing environment. Current predictions of net primary productivity (NPP) in response to elevated atmospheric CO2 concentration are highly variable and contain a considerable amount of uncertainty. Benchmarking model predictions against data are necessary to assess their ability to replicate observed patterns, but also to identify and evaluate the assumptions causing inter-model differences. We have implemented a novel benchmarking workflow as part of the Predictive Ecosystem Analyzer (PEcAn) that is automated, repeatable, and generalized to incorporate different sites and ecological models. Building on the recent Free-Air CO2 Enrichment Model Data Synthesis (FACE-MDS) project, we used observational data from the FACE experiments to test this flexible, extensible benchmarking approach aimed at providing repeatable tests of model process representation that can be performed quickly and frequently. Model performance assessments are often limited to traditional residual error analysis; however, this can result in a loss of critical information. Models that fail tests of relative measures of fit may still perform well under measures of absolute fit and mathematical similarity. This implies that models that are discounted as poor predictors of ecological productivity may still be capturing important patterns. Conversely, models that have been found to be good predictors of productivity may be hiding error in their sub-process that result in the right answers for the wrong reasons. Our suite of tests have not only highlighted process based sources of uncertainty in model productivity calculations, they have also quantified the patterns and scale of this error. Combining these findings with PEcAn's model sensitivity analysis and variance decomposition strengthen our ability to identify which processes

  11. Preferential production and transport of grass-derived pyrogenic carbon in NE-Australian savanna ecosystems

    Science.gov (United States)

    Saiz, Gustavo; Goodrick, Iain; Wurster, Christopher; Nelson, Paul N.; Wynn, Jonathan; Bird, Michael

    2017-12-01

    Understanding the main factors driving fire regimes in grasslands and savannas is critical to better manage their biodiversity and functions. Moreover, improving our knowledge on pyrogenic carbon (PyC) dynamics, including formation, transport and deposition, is fundamental to better understand a significant slow-cycling component of the global carbon cycle, particularly as these ecosystems account for a substantial proportion of the area globally burnt. However, a thorough assessment of past fire regimes in grass-dominated ecosystems is problematic due to challenges in interpreting the charcoal record of sediments. It is therefore critical to adopt appropriate sampling and analytical methods to allow the acquisition of reliable data and information on savanna fire dynamics. This study uses hydrogen pyrolysis (HyPy) to quantify PyC abundance and stable isotope composition (δ13C) in recent sediments across 38 micro-catchments covering a wide range of mixed C3/C4 vegetation in north Queensland, Australia. We exploited the contrasting δ13C values of grasses (i.e. C4; δ13C >-15‰) and woody vegetation (i.e. C3; δ13C <-24‰) to assess the preferential production and transport of grass-derived PyC in savanna ecosystems. Analyses were conducted on bulk and size-fractionated samples to determine the fractions into which PyC preferentially accumulates. Our data show that the δ13C value of PyC in the sediments is decoupled from the δ13C value of total organic carbon, which suggests that a significant component of PyC may be derived from incomplete grass combustion, even when the proportion of C4 grass biomass in the catchment was relatively small. Furthermore, we conducted 16 experimental burns that indicate that there is a comminution of PyC produced in-situ to smaller particles, which facilitates the transport of this material, potentially affecting its preservation potential. Savanna fires preferentially burn the grass understory rather than large trees, leading to

  12. Application of Modern Technologies for Nuclear Power Plant Productivity Improvements

    International Nuclear Information System (INIS)

    Joseph, A. Naser

    2011-01-01

    The nuclear power industry in several countries is concerned about the ability to maintain current high plant performance levels due to aging and obsolescence, knowledge drain, fewer plant staff, new requirements and commitments, unnecessary workloads and stress levels, and human errors. Current plant operations are labor-intensive due to the vast number of operational and support activities required by the commonly used technology in most plants. These concerns increase as plants extend their operating life. In addition, there is the desire by many plants to further improve performance while reducing human errors and increasingly focus on reducing operations and maintenance costs. New productivity improvement capabilities with measurable economic benefits are needed so that a successful business case can be made for their use. Improved and new instrumentation and control, human-system interface, information and communications technologies used properly can address concerns about cost-effectively maintaining current performance levels and enable shifts to even higher performance levels. This can be accomplished through the use of new technology implementations to improve productivity, reduce costs of systemic inefficiencies and avoid unexpected costs. Many of the same type of productivity improvements for operating plants will be applicable for new plants. As new plants are being built, it is important to include these productivity improvements or at least provide the ability to implement them easily later

  13. Hydrogen production at hydro-power plants

    Science.gov (United States)

    Tarnay, D. S.

    A tentative design for hydrogen-producing installations at hydropower facilities is discussed from technological, economic and applications viewpoints. The plants would use alternating current to electrolyze purified river water. The hydrogen would be stored in gas or liquid form and oxygen would be sold or vented to the atmosphere. The hydrogen could later be burned in a turbine generator for meeting peak loads, either in closed or open cycle systems. The concept would allow large hydroelectric plants to function in both base- and peak-load modes, thus increasing the hydraulic utilization of the plant and the capacity factor to a projected 0.90. Electrolyzer efficiencies ranging from 0.85-0.90 have been demonstrated. Excess hydrogen can be sold for other purposes or, eventually, as domestic and industrial fuel, at prices competitive with current industrial hydrogen.

  14. Long-term organic-inorganic fertilization ensures great soil productivity and bacterial diversity after natural-to-agricultural ecosystem conversion.

    Science.gov (United States)

    Xun, Weibing; Xu, Zhihui; Li, Wei; Ren, Yi; Huang, Ting; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-09-01

    Natural ecosystems comprise the planet's wild plant and animal resources, but large tracts of land have been converted to agroecosystems to support the demand for agricultural products. This conversion limits the number of plant species and decreases the soil biological diversity. Here we used high-throughput 16S rRNA gene sequencing to evaluate the responses of soil bacterial communities in long-term converted and fertilized red soils (a type of Ferralic Cambisol). We observed that soil bacterial diversity was strongly affected by different types of fertilization management. Oligotrophic bacterial taxa demonstrated large relative abundances in chemically fertilized soil, whereas copiotrophic bacterial taxa were found in large relative abundances in organically fertilized and fallow management soils. Only organic-inorganic fertilization exhibited the same local taxonomic and phylogenetic diversity as that of a natural ecosystem. However, the independent use of organic or inorganic fertilizer reduced local taxonomic and phylogenetic diversity and caused biotic homogenization. This study demonstrated that the homogenization of bacterial communities caused by natural-to-agricultural ecosystem conversion can be mitigated by employing rational organic-inorganic fertilization management.

  15. Assessing and monitoring impacts of genetically modified plants on agro-ecosystems: the approach of AMIGA project

    Directory of Open Access Journals (Sweden)

    S. Arpaia

    2014-06-01

    Full Text Available The environmental impacts of genetically modified crops is still a controversial issue in Europe. The overall risk assessment framework has recently been reinforced by the European Food Safety Authority(EFSA and its implementation requires harmonized and efficient methodologies. The EU-funded research project AMIGA − Assessing and monitoring Impacts of Genetically modified plants on Agro-ecosystems − aims to address this issue, by providing a framework that establishes protection goals and baselines for European agro-ecosystems, improves knowledge on the potential long term environmental effects of genetically modified (GM plants, tests the efficacy of the EFSA Guidance Document for the Environmental Risk Assessment, explores new strategies for post market monitoring, and provides a systematic analysis of economic aspects of Genetically Modified crops cultivation in the EU. Research focuses on ecological studies in different EU regions, the sustainability of GM crops is estimated by analysing the functional components of the agro-ecosystems and specific experimental protocols are being developed for this scope.

  16. Water and vegetation indices by using MODIS products for eucalyptus, pasture, and natural ecosystems in the eastern São Paulo state, Southeast Brazil

    Science.gov (United States)

    de C. Teixeira, Antônio H.; Leivas, Janice F.; Ronquim, Carlos C.; Garçon, Edlene A. M.; Bayma-Silva, Gustavo

    2017-10-01

    Eucalyptus (Ec) and pasture (Pt) are expanding while natural vegetation (Nv) are losing space in the Paraíba Valley, eastern side of the São Paulo state, Southeast Brazil. For quantification of water and vegetation conditions, the MODIS product MOD13Q1 was used together with a net of weather stations and vegetation land masks during the year 2015. The SAFER algorithm was applied to retrieve the actual evapotranspiration (ET), which was combined with the Monteith's radiation use efficiency (RUE) model to estimate the biomass production (BIO). Three moisture indices were applied, the climatic water balance ratio (WBr), the ratio of precipitation (P) to ET, the water balance deficit (WBd), the difference between P and ET, and the evapotranspiration ratio (ETr), the ratio of ET to the reference evapotranspiration (ET0). On the one hand, the highest ET rates for the Ec ecosystem should be a negative aspect under water scarcity conditions; however, it presented the best water productivity. Although the Ec ecosystem presenting the lowest WBr and WBd values, it had the highest ETr, averaging 0.92, when comparing to those for Nv (0.88) and Pt (0.79). These results indicated that eucalyptus plants have greater ability of conserving soil moisture in their root zones, increasing WP, when comparing with Pt and Nv ecosystems. These water relationships are relevant issues under the land-use change conditions in the Paraiba Valley, confirming the suitability of using the MODIS products together with weather stations to study the ecosystem dynamics.

  17. Comparison of Authorization/Registration/Notification Processes among Biocidal Products, Cosmetics, Plant Protection Products and Human Medicinal Products

    OpenAIRE

    Söyleriz, Yüksel

    2015-01-01

    In this study, comparison of the authorization/registration/notification processes of biocidal products, cosmetics, plant protection products and medicinal products are made and in this respect, the situation in EU is assessed.

  18. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    Science.gov (United States)

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, puranium concentration in plant and the substrate (r=0.88, puranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (puranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. On the sustainable productivity of planted forests

    Science.gov (United States)

    Robert F. Powers

    1999-01-01

    Planted forests have more than a millennium of history and represent the world's best hope for meeting global wood requirements in the twenty-first century. Advances in genetic improvement, nursery practices, stand establishment, and tending, harvesting, and manufacturing have boosted plantation yields to a higher level than at any point in history. Despite this,...

  20. New CHP plant for a rubber products manufacturer

    International Nuclear Information System (INIS)

    Vila, R.; Martí, C.

    2016-01-01

    At the end of 2014 the company Industrias de Hule Galgo decided to undertake the installation project of an efficient CHP plant for its production plant, with the aim of bringing down energy costs and improving the company’s competitive position in the market. The new plant has already started its first operational phase. The project has comprised the installation of a single cycle with gas-powered gensets providing a total electrical capacity of 6.6 MW. This provides the necessary thermal oil for the production plant; covers 100% of the electrical power consumed by the industrial complex; and also generates cooling water, giving improved production capacity by supercooling the extrusion system. To execute these works, Industrias de Hule Galgo contracted the services of engineering company AESA to provide the engineering, procurement and construction of the CHP plant. (Author)

  1. New salty waffle products "Fish Krekis" with fish & plant semifinished products

    Directory of Open Access Journals (Sweden)

    Fedorova Dina

    2016-04-01

    Full Text Available The study examines the directions of expansion of the range of wafer snack products of high nutritional value by using fish & plant semifinished products. The study scientifically grounds the benefits of using the new fish & plant semifinished products in manufacturing waffle salty snack products. The data provided in the article prove that the use of the fish & plant semifinished products & herbal ingredients enable a range of the new wafer snack products «Fish krekis» with high content of proteins, organic calcium, fiber and vitamins, with improved consumer properties, as well as more efficient use of Ukrainian raw fish materials.

  2. Reconceptualizing cancer immunotherapy based on plant production systems

    OpenAIRE

    Hefferon, Kathleen

    2017-01-01

    Plants can be used as inexpensive and facile production platforms for vaccines and other biopharmaceuticals. More recently, plant-based biologics have expanded to include cancer immunotherapy agents. The following review describes the current state of the art for plant-derived strategies to prevent or reduce cancers. The review discusses avenues taken to prevent infection by oncogenic viruses, solid tumors and lymphomas. Strategies including cancer vaccines, monoclonal antibodies and virus na...

  3. Plant compounds insecticide activity against Coleoptera pests of stored products

    OpenAIRE

    MOREIRA, M.D.; PICANÇO, M.C.; BARBOSA, L.C. de A.; GUEDES, R.N.C.; CAMPOS, M.R. de; SILVA, G.A.; MARTINS, J.C.

    2008-01-01

    The objective of this work was to screen plants with insecticide activity, in order to isolate, identify and assess the bioactivity of insecticide compounds present in these plants, against Coleoptera pests of stored products: Oryzaephilus surinamensis L. (Silvanidae), Rhyzopertha dominica F. (Bostrichidae) and Sitophilus zeamais Mots. (Curculionidae). The plant species used were: basil (Ocimum selloi Benth.), rue (Ruta graveolens L.), lion's ear (Leonotis nepetifolia (L.) R.Br.), jimson weed...

  4. Net ecosystem productivity and carbon dynamics of the traditionally managed Imperata grasslands of North East India.

    Science.gov (United States)

    Pathak, Karabi; Malhi, Yadvinder; Sileshi, G W; Das, Ashesh Kumar; Nath, Arun Jyoti

    2018-09-01

    There have been few comprehensive descriptions of how fire management and harvesting affect the carbon dynamics of grasslands. Grasslands dominated by the invasive weed Imperata cylindrica are considered as environmental threats causing low land productivity throughout the moist tropical regions in Asia. Imperata grasslands in North East India are unique in that they are traditionally managed and culturally important in the rural landscapes. Given the importance of fire in the management of Imperata grassland, we aimed to assess (i) the seasonal pattern of biomass production, (ii) the eventual pathways for the produced biomass, partitioned between in situ decomposition, harvesting and combustion, and (iii) the effect of customary fire management on the ecosystem carbon cycle. Comparatively high biomass production was recorded during pre-monsoon (154 g m -2  month -1 ) and monsoon (214 g m -2  month -1 ) compared to the post-monsoon (91 g m -2  month -1 ) season, and this is attributed to nutrient return into the soil immediately after fire in February. Post fire effects might have killed roots and rhizomes leading to high belowground litter production 30-35 g m -2 during March to August. High autotrophic respiration was recorded during March-July, which was related to high belowground biomass production (35-70 g m -2 ) during that time. Burning removed all the surface litter in March and this appeared to hinder surface decomposition and result in low heterotrophic respiration. Annual total biomass carbon production was estimated at 886 g C m -2 . Annual harvest of biomass (estimated at 577 g C m -2 ) was the major pathway for carbon fluxes from the system. Net ecosystem production (NEP) of Imperata grassland was estimated at 91 g C m -2  yr -1 indicating that these grasslands are a net sink of CO 2 , although this is greatly influenced by weather and fire management. Crown Copyright © 2018. Published by Elsevier B

  5. Net primary productivity of China's terrestrial ecosystems from a process model driven by remote sensing.

    Science.gov (United States)

    Feng, X; Liu, G; Chen, J M; Chen, M; Liu, J; Ju, W M; Sun, R; Zhou, W

    2007-11-01

    The terrestrial carbon cycle is one of the foci in global climate change research. Simulating net primary productivity (NPP) of terrestrial ecosystems is important for carbon cycle research. In this study, China's terrestrial NPP was simulated using the Boreal Ecosystem Productivity Simulator (BEPS), a carbon-water coupled process model based on remote sensing inputs. For these purposes, a national-wide database (including leaf area index, land cover, meteorology, vegetation and soil) at a 1 km resolution and a validation database were established. Using these databases and BEPS, daily maps of NPP for the entire China's landmass in 2001 were produced, and gross primary productivity (GPP) and autotrophic respiration (RA) were estimated. Using the simulated results, we explore temporal-spatial patterns of China's terrestrial NPP and the mechanisms of its responses to various environmental factors. The total NPP and mean NPP of China's landmass were 2.235 GtC and 235.2 gCm(-2)yr(-1), respectively; the total GPP and mean GPP were 4.418 GtC and 465 gCm(-2)yr(-1); and the total RA and mean RA were 2.227 GtC and 234 gCm(-2)yr(-1), respectively. On average, NPP was 50.6% of GPP. In addition, statistical analysis of NPP of different land cover types was conducted, and spatiotemporal patterns of NPP were investigated. The response of NPP to changes in some key factors such as LAI, precipitation, temperature, solar radiation, VPD and AWC are evaluated and discussed.

  6. An approach for siting poplar energy production systems to increase productivity and associated ecosystem services

    Science.gov (United States)

    R.S. Jr. Zalesny; D.M. Donner; D.R. Coyle; W.L. Headlee; R.B. Hall

    2010-01-01

    Short rotation woody crops (SRWC) such as Populus species and hybrids (i.e., poplars) are renewable energy feedstocks that are vital to reducing our dependence on non-renewable and foreign sources of energy used for heat, power, and transportation fuels. Highly productive poplars grown primarily on marginal agricultural sites are an important...

  7. Plants for water recycling, oxygen regeneration and food production

    Science.gov (United States)

    Bubenheim, D. L.

    1991-01-01

    During long-duration space missions that require recycling and regeneration of life support materials the major human wastes to be converted to usable forms are CO2, hygiene water, urine and feces. A Controlled Ecological Life Support System (CELSS) relies on the air revitalization, water purification and food production capabilities of higher plants to rejuvenate human wastes and replenish the life support materials. The key processes in such a system are photosynthesis, whereby green plants utilize light energy to produce food and oxygen while removing CO2 from the atmosphere, and transpiration, the evaporation of water from the plant. CELSS research has emphasized the food production capacity and efforts to minimize the area/volume of higher plants required to satisfy all human life support needs. Plants are a dynamic system capable of being manipulated to favour the supply of individual products as desired. The size and energy required for a CELSS that provides virtually all human needs are determined by the food production capacity. Growing conditions maximizing food production do not maximize transpiration of water; conditions favoring transpiration and scaling to recycle only water significantly reduces the area, volume, and energy inputs per person. Likewise, system size can be adjusted to satisfy the air regeneration needs. Requirements of a waste management system supplying inputs to maintain maximum plant productivity are clear. The ability of plants to play an active role in waste processing and the consequence in terms of degraded plant performance are not well characterized. Plant-based life support systems represent the only potential for self sufficiency and food production in an extra-terrestrial habitat.

  8. Cowley Ridge wind plant experiences best production year ever

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The Cowley Ridge wind plant in southern Alberta in its fifth year of operation generated 63,380 MWh of electricity, exceeding its annual goal by about 15 per cent. December was one of the highest production months ever. During December the plant operated an an average of 62 per cent capacity throughout the month. The annual average is 35 per cent of capacity

  9. Optimization of Jatropha curcas pure plant oil production

    NARCIS (Netherlands)

    Subroto, Erna

    2015-01-01

    The use of pure plant oils as fuel, either directly or after conversion of the oil to bio-diesel, is considered to be one of the potential contributions to the transformation of the current fossil oil based economy to a sustainable bio-based one. The production of oil producing seeds using plants

  10. Plant latex lipase as biocatalysts for biodiesel production | Mazou ...

    African Journals Online (AJOL)

    Plant latex lipase as biocatalysts for biodiesel production. ... This paper provides an overview regarding the main aspects of latex, such as the reactions catalyzed, physiological functions, specificities, sources and their industrial applications. Keywords: Plant latex, lipase, Transesterification, purification, biodiesel ...

  11. Entrepreneurial Ecosystems

    NARCIS (Netherlands)

    Stam, F.C.; Spigel, Ben

    2016-01-01

    This paper reviews and discusses the emergent entrepreneurial ecosystem approach. Entrepreneurial ecosystems are defined as a set of interdependent actors and factors coordinated in such a way that they enable productive entrepreneurship within a particular territory. The purpose of this paper is to

  12. Plant natural products research in tuberculosis drug discovery and ...

    African Journals Online (AJOL)

    Plant natural products research in tuberculosis drug discovery and development: A situation report ... African Journal of Biotechnology ... tuberculosis (XDR-TB), call for the development of new anti-tuberculosis drugs to combat this disease.

  13. Initial biochar effects on plant productivity derive from N fertilization

    NARCIS (Netherlands)

    Jeffery, Simon; Memelink, Ilse; Hodgson, Edward; Jones, Sian; van de Voorde, Tess F. J.; Bezemer, T. Martijn; Mommer, Liesje; van Groenigen, Jan Willem

    2017-01-01

    Biochar application to soil is widely claimed to increase plant productivity. However, the underlying mechanisms are still not conclusively described. Here, we aim to elucidate these mechanisms using stable isotope probing.

  14. The heavy water production plant at Arroyito, Argentina

    International Nuclear Information System (INIS)

    Ecabert, R.

    1984-01-01

    The author describes the construction of an industrial heavy water production plant (Planta Industrial de Agua Pesada, PIAP) in Argentina. The heavy water enrichment is based on a hydrogen/ammonia isotope exchange. (Auth.)

  15. What about improving the productivity of electric power plants

    International Nuclear Information System (INIS)

    Lawroski, H.; Knecht, P.D.; Prideaux, D.L.; Zahner, R.R.

    1976-01-01

    The FEA in April of 1974 established an Interagency Task Group on Power Plant Reliability, which was charged with the broad objective of improving the productivity of existing and planned large fossil-fueled and nuclear power plants. It took approximately 11 months for the task force to publish a report, ''Report on Improving the Productivity of Electrical Power Plants'' (FEA-263-G), a detailed analysis and comparison of successful and below-average-performance power plants. The Nuclear Service Corp. portion of this study examined four large central-station power plants: two fossil (coal) and two nuclear plants. Only plants with electrical generation capacities greater than 400 MWe were considered. The study included the following: staff technical skill, engineering support, QA program, plant/corporate coordination, operation philosophy, maintenance programs, federal/state regulations, network control, and equipment problems. Personnel were interviewed, and checklists providing input from some 21 or more plant and corporate personnel of each utility were utilized. Reports and other documentation were also reviewed. It was recognized early that productivity is closely allied to technical skills and positive motivation. For this reason, considerable attention was given to people in this study

  16. Application of plant cell and tissue culture for the production of phytochemicals in medicinal plants.

    Science.gov (United States)

    Pant, Bijaya

    2014-01-01

    Approximately 80% of the world inhabitants depend on the medicinal plants in the form of traditional formulations for their primary health care system well as in the treatment of a number of diseases since the ancient time. Many commercially used drugs have come from the information of indigenous knowledge of plants and their folk uses. Linking of the indigenous knowledge of medicinal plants to modern research activities provides a new reliable approach, for the discovery of novel drugs much more effectively than with random collection. Increase in population and increasing demand of plant products along with illegal trade are causing depletion of medicinal plants and many are threatened in natural habitat. Plant tissue culture technique has proved potential alternative for the production of desirable bioactive components from plants, to produce the enough amounts of plant material that is needed and for the conservation of threatened species. Different plant tissue culture systems have been extensively studied to improve and enhance the production of plant chemicals in various medicinal plants.

  17. Status of ecosystems in radioactive waste reservoirs of the Mayak Production Association in 2009.

    Science.gov (United States)

    Pryakhin, Evgeny A; Tryapitsina, Galina A; Deryabina, Larisa V; Atamanyuk, Natalia I; Stukalov, Pavel M; Ivanov, Ivan A; Kostyuchenko, Vladimir A; Akleyev, Alexander V

    2012-07-01

    Liquid radioactive waste from the Mayak Production Association (Chelyabinsk Region, Russia) is contained in industrial reservoirs (R-11, R-10, R-4, R-17, and R-9) that have different levels of radioactive contamination, increased from R-11 to R-17. A study of the ecosystems in these reservoirs was performed in 2009 to determine if there was any association with the level of contamination. No significant change in the status of biota was found in the reservoir with the lowest radionuclide concentrations (R-11) in comparison to other reservoirs in the region with a similar geography that are unaffected by radioactive contamination. In reservoir R-10, changes in the zoobenthos indices were registered. In reservoir R-4, changes in the zoobenthos and zooplankton communities were registered. In reservoir R-17, there was no ichthyofauna, but strong changes in the phytoplankton, zooplankton, and zoobenthos communities were registered. In reservoir R-9, under the conditions of the heaviest radioactive contamination of water ecosystems in the biosphere, there was no ichthyofauna, and phytoplankton and zooplankton consisted of almost a monoculture of cyanobacteriae and rotifers.

  18. Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

    Science.gov (United States)

    Olson, R. J.; Scurlock, J. M. O.; Turner, R. S.; Jennings, S. V.

    1995-01-01

    Estimating terrestrial net primary production (NPP) using remote-sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Program's (IGBP's) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

  19. Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R.J.; Turner, R.S. [Oak Ridge National Lab., TN (United States); Scurlock, J.M.O. [King`s College London, (England); Jennings, S.V. [Tennessee Univ., Knoxville, TN (United States)

    1995-12-31

    Estimating terrestrial net primary production (NPP) using remote- sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Programme`s (IGBP`s) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

  20. How does whole ecosystem warming of a peatland affect methane production and consumption?

    Science.gov (United States)

    Hopple, A.; Brunik, K.; Keller, J.; Pfeifer-Meister, L.; Woerndle, G.; Zalman, C.; Hanson, P.; Bridgham, S. D.

    2017-12-01

    Peatlands are among Earth's most important terrestrial ecosystems due to their massive soil carbon (C) stores and significant release of methane (CH4) into the atmosphere. Methane has a sustained-flux global warming potential 45-times greater than carbon dioxide (CO2), and the accuracy of Earth system model projections relies on our mechanistic understanding of peatland CH4 cycling in the context of environmental change. The objective of this study was to determine, under in situ conditions, how heating of the peat profile affects ecosystem-level anaerobic C cycling. We assessed the response of CO2 and CH4 production, as well as the anaerobic oxidation of CH4 (AOM), in a boreal peatland following 13 months of deep peat heating (DPH) and 16 months of subsequent whole-ecosystem warming (surface and deep heating; WEW) as part of the Spruce and Peatland Responses Under Changing Environments (SPRUCE) project in northern Minnesota, USA. The study uses a regression-based experimental design including 5 temperature treatments that warmed the entire 2 m peat profile from 0 to +9 °C above ambient temperature. Soil cores were collected at multiple depths (25-200 cm) from each experimental chamber at the SPRUCE site and anaerobically incubated at in situ temperatures for 1-2 weeks. Methane and CO2 production in surface peat were positively correlated with elevated temperature, but no consistent temperature response was found at depth (75-200 cm) following DPH. However, during WEW, we observed significant increases in both surface and deep peat methanogenesis with increasing temperature. Surface peat had greater CH4 production rates than deeper peat, implying that the increased CH4 emissions observed in the field were largely driven by surface peat warming. The CO2:CH4 ratio was inversely correlated with temperature across all depths following 16 months of WEW, indicating that the entire peat profile is becoming more methanogenic with warming. We also observed AOM throughout

  1. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Directory of Open Access Journals (Sweden)

    Sameer Dixit

    Full Text Available Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR and spectra showed up to 16 fold higher methanol as compared to control wild type (WT plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid and Bemisia tabaci (whitefly, respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  2. Enhanced Methanol Production in Plants Provides Broad Spectrum Insect Resistance

    Science.gov (United States)

    Dixit, Sameer; Upadhyay, Santosh Kumar; Singh, Harpal; Sidhu, Om Prakash; Verma, Praveen Chandra; K, Chandrashekar

    2013-01-01

    Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants. PMID:24223989

  3. Fiber optic lighting system for plant production

    Science.gov (United States)

    St. George, Dennis R.; Feddes, John J. R.

    1991-02-01

    Dennis St. George John Feddes (Dept. of Agricultural Engineering University of Alberta Edmonton AB Canada T6G 2Hl) A prototype light collection and transmission device was developed and evaluated for the potential of irradiating plants grown in an opague growth chamber. Results indicated that the device transmitted light with a photon flux of 130 1amol/s/m2 (4000-7000 nm) to the bottom of the growth chamber when direct solar radiation was 800 W/m2 (300-2500 nm) outside. The overall collection and transmission efficiency for photosynthetically active radiation is 19. 2. A growth trial with plants indicated that artificial lighting is required during cloudy periods. 1.

  4. Impacts of droughts and extreme-temperature events on gross primary production and ecosystem respiration: a systematic assessment across ecosystems and climate zones

    Science.gov (United States)

    von Buttlar, Jannis; Zscheischler, Jakob; Rammig, Anja; Sippel, Sebastian; Reichstein, Markus; Knohl, Alexander; Jung, Martin; Menzer, Olaf; Altaf Arain, M.; Buchmann, Nina; Cescatti, Alessandro; Gianelle, Damiano; Kiely, Gerard; Law, Beverly E.; Magliulo, Vincenzo; Margolis, Hank; McCaughey, Harry; Merbold, Lutz; Migliavacca, Mirco; Montagnani, Leonardo; Oechel, Walter; Pavelka, Marian; Peichl, Matthias; Rambal, Serge; Raschi, Antonio; Scott, Russell L.; Vaccari, Francesco P.; van Gorsel, Eva; Varlagin, Andrej; Wohlfahrt, Georg; Mahecha, Miguel D.

    2018-03-01

    Extreme climatic events, such as droughts and heat stress, induce anomalies in ecosystem-atmosphere CO2 fluxes, such as gross primary production (GPP) and ecosystem respiration (Reco), and, hence, can change the net ecosystem carbon balance. However, despite our increasing understanding of the underlying mechanisms, the magnitudes of the impacts of different types of extremes on GPP and Reco within and between ecosystems remain poorly predicted. Here we aim to identify the major factors controlling the amplitude of extreme-event impacts on GPP, Reco, and the resulting net ecosystem production (NEP). We focus on the impacts of heat and drought and their combination. We identified hydrometeorological extreme events in consistently downscaled water availability and temperature measurements over a 30-year time period. We then used FLUXNET eddy covariance flux measurements to estimate the CO2 flux anomalies during these extreme events across dominant vegetation types and climate zones. Overall, our results indicate that short-term heat extremes increased respiration more strongly than they downregulated GPP, resulting in a moderate reduction in the ecosystem's carbon sink potential. In the absence of heat stress, droughts tended to have smaller and similarly dampening effects on both GPP and Reco and, hence, often resulted in neutral NEP responses. The combination of drought and heat typically led to a strong decrease in GPP, whereas heat and drought impacts on respiration partially offset each other. Taken together, compound heat and drought events led to the strongest C sink reduction compared to any single-factor extreme. A key insight of this paper, however, is that duration matters most: for heat stress during droughts, the magnitude of impacts systematically increased with duration, whereas under heat stress without drought, the response of Reco over time turned from an initial increase to a downregulation after about 2 weeks. This confirms earlier theories that

  5. Diverse urban plantings managed with sufficient resource availability can increase plant productivity and arthropod diversity

    Directory of Open Access Journals (Sweden)

    Jonathon eMuller

    2014-10-01

    Full Text Available Buildings structures and surfaces are explicitly being used to grow plants, and these ‘urban plantings’ are typically designed for aesthetic value. Urban plantings also have the potential to contribute significant ‘ecological values’ by increasing urban habitat for animals such as arthropods and by increasing plant productivity. In this study, we evaluated how the provision of these additional ecological values is affected by plant species richness; the availability of essential resources for plants, such as water, light, space; and soil characteristics. We sampled 33 plantings located on the exterior of three buildings in the urban centre of Brisbane, Australia (subtropical climatic region over two, six week sampling periods characterised by different temperature and rainfall conditions. Plant cover was estimated as a surrogate for productivity as destructive sampling of biomass was not possible. We measured weekly light levels (photosynthetically active radiation, plant CO2 assimilation, soil CO2 efflux, and arthropod diversity.Differences in plant cover were best explained by a three-way interaction of plant species richness, management water regime and sampling period. As the richness of plant species increased in a planter, productivity and total arthropod richness also increased significantly - likely due to greater habitat heterogeneity and quality. Overall we found urban plantings can provide additional ecological values if essential resources are maintained within a planter such as water, light and soil temperature. Diverse urban plantings that are managed with these principles in mind can contribute to the attraction of diverse arthropod communities, and lead to increased plant productivity within a dense urban context.

  6. Plant Products for Pharmacology: Application of Enzymes in Their Transformations

    Directory of Open Access Journals (Sweden)

    Marie Zarevúcka

    2008-12-01

    Full Text Available Different plant products have been subjected to detailed investigations due to their increasing importance for improving human health. Plants are sources of many groups of natural products, of which large number of new compounds has already displayed their high impact in human medicine. This review deals with the natural products which may be found dissolved in lipid phase (phytosterols, vitamins etc.. Often subsequent convenient transformation of natural products may further improve the pharmacological properties of new potential medicaments based on natural products. To respect basic principles of sustainable and green procedures, enzymes are often employed as efficient natural catalysts in such plant product transformations. Transformations of lipids and other natural products under the conditions of enzyme catalysis show increasing importance in environmentally safe and sustainable production of pharmacologically important compounds. In this review, attention is focused on lipases, efficient and convenient biocatalysts for the enantio- and regioselective formation / hydrolysis of ester bond in a wide variety of both natural and unnatural substrates, including plant products, eg. plant oils and other natural lipid phase compounds. The application of enzymes for preparation of acylglycerols and transformation of other natural products provides big advantage in comparison with employing of conventional chemical methods: Increased selectivity, higher product purity and quality, energy conservation, elimination of heavy metal catalysts, and sustainability of the employed processes, which are catalyzed by enzymes. Two general procedures are used in the transformation of lipid-like natural products: (a Hydrolysis/alcoholysis of triacylglycerols and (b esterification of glycerol. The reactions can be performed under conventional conditions or in supercritical fluids/ionic liquids. Enzyme-catalyzed reactions in supercritical fluids combine the

  7. Production of lysosomal enzymes in plant-based expression systems

    OpenAIRE

    1996-01-01

    The invention relates to the production of enzymatically active recombinant human and animal lysosomal enzymes involving construction and expression of recombinant expression constructs comprising coding sequences of human or animal lysosomal enzymes in a plant expression system. The plant expression system provides for post-translational modification and processing to produce a recombinant gene product exhibiting enzymatic activity. The invention is demonstrated by working examples in which ...

  8. Comparing bioenergy production sites in the Southeastern US regarding ecosystem service supply and demand.

    Directory of Open Access Journals (Sweden)

    Markus A Meyer

    Full Text Available Biomass for bioenergy is debated for its potential synergies or tradeoffs with other provisioning and regulating ecosystem services (ESS. This biomass may originate from different production systems and may be purposefully grown or obtained from residues. Increased concerns globally about the sustainable production of biomass for bioenergy has resulted in numerous certification schemes focusing on best management practices, mostly operating at the plot/field scale. In this study, we compare the ESS of two watersheds in the southeastern US. We show the ESS tradeoffs and synergies of plantation forestry, i.e., pine poles, and agricultural production, i.e., wheat straw and corn stover, with the counterfactual natural or semi-natural forest in both watersheds. The plantation forestry showed less distinct tradeoffs than did corn and wheat production, i.e., for carbon storage, P and sediment retention, groundwater recharge, and biodiversity. Using indicators of landscape composition and configuration, we showed that landscape planning can affect the overall ESS supply and can partly determine if locally set environmental thresholds are being met. Indicators on landscape composition, configuration and naturalness explained more than 30% of the variation in ESS supply. Landscape elements such as largely connected forest patches or more complex agricultural patches, e.g., mosaics with shrub and grassland patches, may enhance ESS supply in both of the bioenergy production systems. If tradeoffs between biomass production and other ESS are not addressed by landscape planning, it may be reasonable to include rules in certification schemes that require, e.g., the connectivity of natural or semi-natural forest patches in plantation forestry or semi-natural landscape elements in agricultural production systems. Integrating indicators on landscape configuration and composition into certification schemes is particularly relevant considering that certification

  9. Comparing Bioenergy Production Sites in the Southeastern US Regarding Ecosystem Service Supply and Demand

    Science.gov (United States)

    Meyer, Markus A.; Chand, Tanzila; Priess, Joerg A.

    2015-01-01

    Biomass for bioenergy is debated for its potential synergies or tradeoffs with other provisioning and regulating ecosystem services (ESS). This biomass may originate from different production systems and may be purposefully grown or obtained from residues. Increased concerns globally about the sustainable production of biomass for bioenergy has resulted in numerous certification schemes focusing on best management practices, mostly operating at the plot/field scale. In this study, we compare the ESS of two watersheds in the southeastern US. We show the ESS tradeoffs and synergies of plantation forestry, i.e., pine poles, and agricultural production, i.e., wheat straw and corn stover, with the counterfactual natural or semi-natural forest in both watersheds. The plantation forestry showed less distinct tradeoffs than did corn and wheat production, i.e., for carbon storage, P and sediment retention, groundwater recharge, and biodiversity. Using indicators of landscape composition and configuration, we showed that landscape planning can affect the overall ESS supply and can partly determine if locally set environmental thresholds are being met. Indicators on landscape composition, configuration and naturalness explained more than 30% of the variation in ESS supply. Landscape elements such as largely connected forest patches or more complex agricultural patches, e.g., mosaics with shrub and grassland patches, may enhance ESS supply in both of the bioenergy production systems. If tradeoffs between biomass production and other ESS are not addressed by landscape planning, it may be reasonable to include rules in certification schemes that require, e.g., the connectivity of natural or semi-natural forest patches in plantation forestry or semi-natural landscape elements in agricultural production systems. Integrating indicators on landscape configuration and composition into certification schemes is particularly relevant considering that certification schemes are governance

  10. Comparing bioenergy production sites in the Southeastern US regarding ecosystem service supply and demand.

    Science.gov (United States)

    Meyer, Markus A; Chand, Tanzila; Priess, Joerg A

    2015-01-01

    Biomass for bioenergy is debated for its potential synergies or tradeoffs with other provisioning and regulating ecosystem services (ESS). This biomass may originate from different production systems and may be purposefully grown or obtained from residues. Increased concerns globally about the sustainable production of biomass for bioenergy has resulted in numerous certification schemes focusing on best management practices, mostly operating at the plot/field scale. In this study, we compare the ESS of two watersheds in the southeastern US. We show the ESS tradeoffs and synergies of plantation forestry, i.e., pine poles, and agricultural production, i.e., wheat straw and corn stover, with the counterfactual natural or semi-natural forest in both watersheds. The plantation forestry showed less distinct tradeoffs than did corn and wheat production, i.e., for carbon storage, P and sediment retention, groundwater recharge, and biodiversity. Using indicators of landscape composition and configuration, we showed that landscape planning can affect the overall ESS supply and can partly determine if locally set environmental thresholds are being met. Indicators on landscape composition, configuration and naturalness explained more than 30% of the variation in ESS supply. Landscape elements such as largely connected forest patches or more complex agricultural patches, e.g., mosaics with shrub and grassland patches, may enhance ESS supply in both of the bioenergy production systems. If tradeoffs between biomass production and other ESS are not addressed by landscape planning, it may be reasonable to include rules in certification schemes that require, e.g., the connectivity of natural or semi-natural forest patches in plantation forestry or semi-natural landscape elements in agricultural production systems. Integrating indicators on landscape configuration and composition into certification schemes is particularly relevant considering that certification schemes are governance

  11. Geometagenomics illuminates the impact of agriculture on the distribution and prevalence of plant viruses at the ecosystem scale.

    Science.gov (United States)

    Bernardo, Pauline; Charles-Dominique, Tristan; Barakat, Mohamed; Ortet, Philippe; Fernandez, Emmanuel; Filloux, Denis; Hartnady, Penelope; Rebelo, Tony A; Cousins, Stephen R; Mesleard, François; Cohez, Damien; Yavercovski, Nicole; Varsani, Arvind; Harkins, Gordon W; Peterschmitt, Michel; Malmstrom, Carolyn M; Martin, Darren P; Roumagnac, Philippe

    2018-01-01

    Disease emergence events regularly result from human activities such as agriculture, which frequently brings large populations of genetically uniform hosts into contact with potential pathogens. Although viruses cause nearly 50% of emerging plant diseases, there is little systematic information about virus distribution across agro-ecological interfaces and large gaps in understanding of virus diversity in nature. Here we applied a novel landscape-scale geometagenomics approach to examine relationships between agricultural land use and distributions of plant-associated viruses in two Mediterranean-climate biodiversity hotspots (Western Cape region of South Africa and Rhône river delta region of France). In total, we analysed 1725 geo-referenced plant samples collected over two years from 4.5 × 4.5 km 2 grids spanning farmlands and adjacent uncultivated vegetation. We found substantial virus prevalence (25.8-35.7%) in all ecosystems, but prevalence and identified family-level virus diversity were greatest in cultivated areas, with some virus families displaying strong agricultural associations. Our survey revealed 94 previously unknown virus species, primarily from uncultivated plants. This is the first effort to systematically evaluate plant-associated viromes across broad agro-ecological interfaces. Our findings indicate that agriculture substantially influences plant virus distributions and highlight the extent of current ignorance about the diversity and roles of viruses in nature.

  12. The Date Palm Tree Rhizosphere Is a Niche for Plant Growth Promoting Bacteria in the Oasis Ecosystem

    Directory of Open Access Journals (Sweden)

    Raoudha Ferjani

    2015-01-01

    Full Text Available In arid ecosystems environmental factors such as geoclimatic conditions and agricultural practices are of major importance in shaping the diversity and functionality of plant-associated bacterial communities. Assessing the influence of such factors is a key to understand (i the driving forces determining the shape of root-associated bacterial communities and (ii the plant growth promoting (PGP services they provide. Desert oasis environment was chosen as model ecosystem where agriculture is possible by the microclimate determined by the date palm cultivation. The bacterial communities in the soil fractions associated with the root system of date palms cultivated in seven oases in Tunisia were assessed by culture-independent and dependent approaches. According to 16S rRNA gene PCR-DGGE fingerprinting, the shapes of the date palm rhizosphere bacterial communities correlate with geoclimatic features along a north-south aridity transect. Despite the fact that the date palm root bacterial community structure was strongly influenced by macroecological factors, the potential rhizosphere services reflected in the PGP traits of isolates screened in vitro were conserved among the different oases. Such services were exerted by the 83% of the screened isolates. The comparable numbers and types of PGP traits indicate their importance in maintaining the plant functional homeostasis despite the different environmental selection pressures.

  13. The Date Palm Tree Rhizosphere Is a Niche for Plant Growth Promoting Bacteria in the Oasis Ecosystem

    KAUST Repository

    Ferjani, Raoudha

    2015-04-01

    In arid ecosystems environmental factors such as geoclimatic conditions and agricultural practices are of major importance in shaping the diversity and functionality of plant-associated bacterial communities. Assessing the influence of such factors is a key to understand (i) the driving forces determining the shape of root-associated bacterial communities and (ii) the plant growth promoting (PGP) services they provide. Desert oasis environment was chosen as model ecosystem where agriculture is possible by the microclimate determined by the date palm cultivation. The bacterial communities in the soil fractions associated with the root system of date palms cultivated in seven oases in Tunisia were assessed by culture-independent and dependent approaches. According to 16S rRNA gene PCR-DGGE fingerprinting, the shapes of the date palm rhizosphere bacterial communities correlate with geoclimatic features along a north-south aridity transect. Despite the fact that the date palm root bacterial community structure was strongly influenced by macroecological factors, the potential rhizosphere services reflected in the PGP traits of isolates screened in vitro were conserved among the different oases. Such services were exerted by the 83% of the screened isolates. The comparable numbers and types of PGP traits indicate their importance in maintaining the plant functional homeostasis despite the different environmental selection pressures.

  14. The Date Palm Tree Rhizosphere Is a Niche for Plant Growth Promoting Bacteria in the Oasis Ecosystem

    KAUST Repository

    Ferjani, Raoudha; Marasco, Ramona; Rolli, Eleonora; Cherif, Hanene; Cherif, Ameur; Gtari, Maher; Boudabous, Abdellatif; Daffonchio, Daniele; Ouzari, Hadda-Imene

    2015-01-01

    In arid ecosystems environmental factors such as geoclimatic conditions and agricultural practices are of major importance in shaping the diversity and functionality of plant-associated bacterial communities. Assessing the influence of such factors is a key to understand (i) the driving forces determining the shape of root-associated bacterial communities and (ii) the plant growth promoting (PGP) services they provide. Desert oasis environment was chosen as model ecosystem where agriculture is possible by the microclimate determined by the date palm cultivation. The bacterial communities in the soil fractions associated with the root system of date palms cultivated in seven oases in Tunisia were assessed by culture-independent and dependent approaches. According to 16S rRNA gene PCR-DGGE fingerprinting, the shapes of the date palm rhizosphere bacterial communities correlate with geoclimatic features along a north-south aridity transect. Despite the fact that the date palm root bacterial community structure was strongly influenced by macroecological factors, the potential rhizosphere services reflected in the PGP traits of isolates screened in vitro were conserved among the different oases. Such services were exerted by the 83% of the screened isolates. The comparable numbers and types of PGP traits indicate their importance in maintaining the plant functional homeostasis despite the different environmental selection pressures.

  15. State regulation and power plant productivity: background and recommendations

    International Nuclear Information System (INIS)

    1980-09-01

    This report was prepared by representatives of several state regulatory agencies. It is a guide to some of the activities currently under way in state agencies to promote increased availability of electrical generating power plants. Standard measures of plant performance are defined and the nature of data bases that report such measures is discussed. It includes reviews of current state, federal, and industry programs to enhance power plant productivity and provides detailed outlines of programs in effect in California, Illinois, Michigan, New York, North Carolina, Ohio, and Texas. A number of actions are presented that could be adopted by state regulatory agencies, depending on local conditions. They include: develop a commission position or policy statement to encourage productivity improvements by utilities; coordinate state efforts with ongoing industry and government programs to improve the acquisition of power plant performance data and the maintenance of quality information systems; acquire the capability to perform independent analyses of power plant productivity; direct the establishment of productivity improvement programs, including explicit performance objectives for both existing and planned power plants, and a performance program; establish a program of incentives to motivate productivity improvement activities; and participate in ongoing efforts at all levels and initiate new actions to promote productivity improvements

  16. Maintenance in nuclear production power plants

    International Nuclear Information System (INIS)

    Lozano, J. M.

    2010-01-01

    This article highlights the importance and quality of maintenance in the complete phases of development, in a sector which has been often questioned by the public opinion, and that is always subject to national and international standards. The aim of maintenance is to guarantee the production of electric power in a reliable, safe, economic and friendly environmentally way, assuring a long-term production. (Author)

  17. Ecological Production Functions Linking Multiple Stressors to Ecosystem Services – A Case Study

    Science.gov (United States)

    The ecosystem services concept is being used to frame environmental protection goals that guide management of the risks of chemicals. Ecosystem services link changes in ecological systems to the benefits received by people. The use of ecosystem services in risk assessments and th...

  18. Increasing production, the sustained yield method, and reserve structure of agrisilvicultural ecosystems in the moist tropics

    Energy Technology Data Exchange (ETDEWEB)

    Bruenig, E F

    1980-09-01

    While substantial improvements first of all require a profound change of political attitudes and the replacement of irrational ideological creeds, improvements of the food situation in addition needs the application of ecologically adapted and economically sound land use techniques. This in turn requires scientific knowledge of the interrelationships between site factors and the structure and functions of crop types. The principles of the structural design of tropical virgin forest ecosystems can be usefully adapted for the development of agroforestry crop types. Such crop types should be capable of producing a sustained yield of food, timber, fuel, medicinal substances, spices and other useful products and, in addition, produce favourable, stabilizing effects on the local, regional and finally global biosphere.

  19. Variations of net ecosystem production due to seasonal precipitation differences in a tropical dry forest of northwest Mexico

    Science.gov (United States)

    Verduzco, Vivian S.; Garatuza-Payán, Jaime; Yépez, Enrico A.; Watts, Christopher J.; Rodríguez, Julio C.; Robles-Morua, Agustin; Vivoni, Enrique R.

    2015-10-01

    Due to their large extent and high primary productivity, tropical dry forests (TDF) are important contributors to atmospheric carbon exchanges in subtropical and tropical regions. In northwest Mexico, a bimodal precipitation regime that includes winter precipitation derived from Pacific storms and summer precipitation from the North American monsoon (NAM) couples water availability with ecosystem processes. We investigated the net ecosystem production of a TDF ecosystem using a 4.5 year record of water and carbon fluxes obtained from the eddy covariance method complemented with remotely sensed data. We identified a large CO2 efflux at the start of the summer season that is strongly related to the preceding winter precipitation and greenness. Since this CO2 efflux occurs prior to vegetation green-up, we infer that respiration is mainly due to decomposition of soil organic matter accumulated from the prior growing season. Overall, ecosystem respiration has an important effect on the net ecosystem production but can be overwhelmed by the strength of the primary productivity during the NAM. Precipitation characteristics during NAM have significant controls on sustaining carbon fixation in the TDF into the fall season. We identified that a threshold of ~350 to 400 mm of monsoon precipitation leads to a switch in the annual carbon balance in the TDF ecosystem from a net source (+102 g C/m2/yr) to a net sink (-249 g C/m2/yr). This monsoonal precipitation threshold is typically exceeded one out of every 2 years. The close coupling of winter and summer periods with respect to carbon fluxes suggests that the annual carbon balance is dependent on precipitation amounts in both seasons in TDF ecosystems.

  20. Optimizing Photosynthetic and Respiratory Parameters Based on the Seasonal Variation Pattern in Regional Net Ecosystem Productivity Obtained from Atmospheric Inversion

    Science.gov (United States)

    Chen, Z.; Chen, J.; Zheng, X.; Jiang, F.; Zhang, S.; Ju, W.; Yuan, W.; Mo, G.

    2014-12-01

    In this study, we explore the feasibility of optimizing ecosystem photosynthetic and respiratory parameters from the seasonal variation pattern of the net carbon flux. An optimization scheme is proposed to estimate two key parameters (Vcmax and Q10) by exploiting the seasonal variation in the net ecosystem carbon flux retrieved by an atmospheric inversion system. This scheme is implemented to estimate Vcmax and Q10 of the Boreal Ecosystem Productivity Simulator (BEPS) to improve its NEP simulation in the Boreal North America (BNA) region. Simultaneously, in-situ NEE observations at six eddy covariance sites are used to evaluate the NEE simulations. The results show that the performance of the optimized BEPS is superior to that of the BEPS with the default parameter values. These results have the implication on using atmospheric CO2 data for optimizing ecosystem parameters through atmospheric inversion or data assimilation techniques.

  1. Reconceptualizing cancer immunotherapy based on plant production systems

    Science.gov (United States)

    Hefferon, Kathleen

    2017-01-01

    Plants can be used as inexpensive and facile production platforms for vaccines and other biopharmaceuticals. More recently, plant-based biologics have expanded to include cancer immunotherapy agents. The following review describes the current state of the art for plant-derived strategies to prevent or reduce cancers. The review discusses avenues taken to prevent infection by oncogenic viruses, solid tumors and lymphomas. Strategies including cancer vaccines, monoclonal antibodies and virus nanoparticles are described, and examples are provided. The review ends with a discussion of the implications of plant-based cancer immunotherapy for developing countries. PMID:28884013

  2. Combining multiple ecosystem productivity measurements to constrain carbon uptake estimates in semiarid grasslands and shrublands

    Science.gov (United States)

    Maurer, G. E.; Krofcheck, D. J.; Collins, S. L.; Litvak, M. E.

    2016-12-01

    Recent observational and modeling studies have indicated that semiarid ecosystems are more dynamic contributors to the global carbon budget than once thought. Semiarid carbon fluxes, however, are generally small, with high interannual and spatial variability, which suggests that validating their global significance may depend on examining multiple productivity measures and their associated uncertainties and inconsistencies. We examined ecosystem productivity from eddy covariance (NEE), harvest (NPP), and terrestrial biome models (NEPm) at two very similar grassland sites and one creosote shrubland site in the Sevilleta National Wildlife Refuge of central New Mexico, USA. Our goal was to assess site and methodological correspondence in annual carbon uptake, patterns of interannual variability, and measurement uncertainty. One grassland site was a perennial carbon source losing 30 g C m-2 per year on average, while the other two sites were carbon sources or sinks depending on the year, with average net uptake of 5 and 25 g C m-2 per year at the grassland and shrubland site, respectively. Uncertainty values for cumulative annual NEE overlapped between the three sites in most years. When combined, aboveground and belowground annual NPP measurements were 15% higher than annual NEE values and did not confirm a loss of carbon at any site in any year. Despite differences in mean site carbon balance, year-to-year changes in cumulative annual NEE and NPP were similar at all sites with years 2010 and 2013 being favorable for carbon uptake and 2011 and 2012 being unfavorable at all sites. Modeled NEPm data for a number of nearby grid cells reproduced only a fraction of the observed range in carbon uptake and its interannual variability. These three sites are highly similar in location and climate and multiple carbon flux measurements confirm the high interannual variability in carbon flux. The exact magnitude of these fluxes, however, remains difficult to discern.

  3. Uncertainty Source of Modeled Ecosystem Productivity in East Asian Monsoon Region: A Traceability Analysis

    Science.gov (United States)

    Cui, E.; Xia, J.; Huang, K.; Ito, A.; Arain, M. A.; Jain, A. K.; Poulter, B.; Peng, C.; Hayes, D. J.; Ricciuto, D. M.; Huntzinger, D. N.; Tian, H.; Mao, J.; Fisher, J.; Schaefer, K. M.; Huang, M.; Peng, S.; Wang, W.

    2017-12-01

    East Asian monsoon region, benefits from sufficient water-heat availability and increasing nitrogen deposition, represents significantly higher net ecosystem productivity than the same latitudes of Europe-Africa and North America. A better understanding of major contributions to the uncertainties of terrestrial carbon cycle in this region is greatly important for evaluating the global carbon balance. This study analyzed the key carbon processes and parameters derived from a series of terrestrial biosphere models. A wide range of inter-model disagreement on GPP was found in China's subtropical regions. Then, this large difference was traced to a few traceable components included in terrestrial carbon cycle. The increase in ensemble mean GPP over 1901-2010 was predominantly resulted from increasing atmospheric CO2 concentration and nitrogen deposition, while high frequent land-use change over this region showed a slightly negative effect on GPP. However, inter-model differences of GPP were mainly attributed to the baseline simulations without changes in external forcing. According to the variance decomposition, the large spread in simulated GPP was well explained by the differences in leaf area index (LAI) and specific leaf area (SLA) among models. In addition, the underlying errors in simulated GPP propagate through the model and introduce some additional errors to the simulation of NPP and biomass. By comparing the simulations with satellite-derived, data-oriented and observation-based datasets, we further found that GPP, vegetation carbon turn-over time, aboveground biomass, LAI and SLA were all overestimated in most of the models while biomass distribution in leaves was significantly underestimated. The results of this study indicate that model performance on ecosystem productivity in East Asian monsoon region can be improved by a more realistic representation of leaf functional traits.

  4. Optimal planting systems for cut gladiolus and stock production

    Directory of Open Access Journals (Sweden)

    Iftikhar Ahmad

    2017-10-01

    Full Text Available A study was conducted to elucidate the effect of different planting systems, videlicet (viz. flat, ridge, and raised bed system on growth, yield and quality of gladiolus and stock. Corms of ‘Rose Supreme’ and ‘White Prosperity’ gladiolus and seedlings of ‘Cheerful White’, ‘Lucinda Dark Rose Double’ and ‘Lucinda Dark Rose Single’ stock were planted on different planting systems in individual experiments for each species. Gladiolus had similar good quality production irrespective of planting systems with numerical superiority of ridge planting, which produced longer stems with higher stem fresh weight, but delayed corm sprouting by ca. 1 d compared to raised bed or flat planting system. Among cultivars, ‘Rose Supreme’ produced higher number of florets per spike, taller stems with longer spikes, higher fresh weight of stems and higher number of cormels than ‘White Prosperity’. Stock plants grown on flat beds produced stems with greater stem length, leaf area and fresh weight of stems compared to ridge or raised bed planting systems. Plants grown on ridges produced the highest stem diameter, number of leaves per plant, total leaf chlorophyll contents, and number of flowers per spike. ‘Cheerful White’ and ‘Lucinda Dark Rose Double’ performed best by producing good quality stems in shorter period compared to ‘Lucinda Dark Rose Single’. In summary, gladiolus should be grown on ridges, while stock may be planted on flat beds for higher yields of better quality flowers.

  5. Variability and Changes in Climate, Phenology, and Gross Primary Production of an Alpine Wetland Ecosystem

    Directory of Open Access Journals (Sweden)

    Xiaoming Kang

    2016-05-01

    Full Text Available Quantifying the variability and changes in phenology and gross primary production (GPP of alpine wetlands in the Qinghai–Tibetan Plateau under climate change is essential for assessing carbon (C balance dynamics at regional and global scales. In this study, in situ eddy covariance (EC flux tower observations and remote sensing data were integrated with a modified, satellite-based vegetation photosynthesis model (VPM to investigate the variability in climate change, phenology, and GPP of an alpine wetland ecosystem, located in Zoige, southwestern China. Two-year EC data and remote sensing vegetation indices showed that warmer temperatures corresponded to an earlier start date of the growing season, increased GPP, and ecosystem respiration, and hence increased the C sink strength of the alpine wetlands. Twelve-year long-term simulations (2000–2011 showed that: (1 there were significantly increasing trends for the mean annual enhanced vegetation index (EVI, land surface water index (LSWI, and growing season GPP (R2 ≥ 0.59, p < 0.01 at rates of 0.002, 0.11 year−1 and 16.32 g·C·m−2·year−1, respectively, which was in line with the observed warming trend (R2 = 0.54, p = 0.006; (2 the start and end of the vegetation growing season (SOS and EOS experienced a continuous advancing trend at a rate of 1.61 days·year−1 and a delaying trend at a rate of 1.57 days·year−1 from 2000 to 2011 (p ≤ 0.04, respectively; and (3 with increasing temperature, the advanced SOS and delayed EOS prolonged the wetland’s phenological and photosynthetically active period and, thereby, increased wetland productivity by about 3.7–4.2 g·C·m−2·year−1 per day. Furthermore, our results indicated that warming and the extension of the growing season had positive effects on carbon uptake in this alpine wetland ecosystem.

  6. Production characteristics of lettuce Lactuca sativa L. in the frame of the first crop tests in the Higher Plant Chamber integrated into the MELiSSA Pilot Plant

    Science.gov (United States)

    Tikhomirova, Natalia; Lawson, Jamie; Stasiak, Michael; Dixon, Mike; Paille, Christel; Peiro, Enrique; Fossen, Arnaud; Godia, Francesc

    Micro-Ecological Life Support System Alternative (MELiSSA) is an artificial closed ecosystem that is considered a tool for the development of a bioregenerative life support system for manned space missions. One of the five compartments of MELiSSA loop -Higher Plant Chamber was recently integrated into the MELiSSA Pilot Plant facility at Universitat Aut`noma deo Barcelona. The main contributions expected by integration of this photosynthetic compartment are oxygen, water, vegetable food production and CO2 consumption. Production characteristics of Lactuca sativa L., as a MELiSSA candidate crop, were investigated in this work in the first crop experiments in the MELiSSA Pilot Plant facility. The plants were grown in batch culture and totaled 100 plants with a growing area 5 m long and 1 m wide in a sealed controlled environment. Several replicates of the experiments were carried out with varying duration. It was shown that after 46 days of lettuce cultivation dry edible biomass averaged 27, 2 g per plant. However accumulation of oxygen in the chamber, which required purging of the chamber, and decrease in the food value of the plants was observed. Reducing the duration of the tests allowed uninterrupted test without opening the system and also allowed estimation of the crop's carbon balance. Results of productivity, tissue composition, nutrient uptake and canopy photosynthesis of lettuce regardless of test duration are discussed in the paper.

  7. Safeguarding production agriculture and natural ecosystems against biological terrorism. A U.S. Department of Agriculture emergency response framework.

    Science.gov (United States)

    Sequeira, R

    1999-01-01

    Foreign pest introductions and outbreaks represent threats to agricultural productivity and ecosystems, and, thus, to the health and national security of the United States. It is advisable to identify relevant techniques and bring all appropriate strategies to bear on the problem of controlling accidentally and intentionally introduced pest outbreaks. Recent political shifts indicate that the U.S. may be at increased risk for biological terrorism. The existing emergency-response strategies of the Animal and Plant Health Inspection Services (APHIS) will evolve to expand activities in coordination with other emergency management agencies. APHIS will evolve its information superstructure to include extensive application of simulation models for forecasting, meteorological databases and analysis, systems analysis, geographic information systems, satellite image analysis, remote sensing, and the training of specialized cadres within the emergency-response framework capable of managing the necessary information processing and analysis. Finally, the threat of key pests ranked according to perceived risk will be assessed with mathematical models and "what-if" scenarios analyzed to determine impact and mitigation practices. An infrastructure will be maintained that periodically surveys ports and inland regions for the presence of exotic pest threats and will identify trend abnormalities. This survey and monitoring effort will include cooperation from industry groups, federal and state organizations, and academic institutions.

  8. Modelling Macroalgae Productivity In An Estuary. A Biorremediation To Nutrient Discharges In The Ecosystems.

    Science.gov (United States)

    Alvera-Azcárate, A.; Ferreira, J. G.; Nunes, J. P.

    Enhanced nutrient load to estuaries and coastal waters due to anthropogenic activities is damaging aquatic ecosystems, resulting in water pollution and eutrophication prob- lems. It is important to quantify the production of photosynthetic organisms, as they play an important role in controlling nitrogen removal and nitrogen fluxes between the sediments and the water column. In turbid estuaries, such as those on the NE Atlantic coast of Europe, benthic primary producers such as macroalgae may play an important part in carbon fixation and nutrient removal, since pelagic production is often strongly light-limited. Estuarine seaweeds are primarily located in intertidal areas, which are characterised by shallow waters and strong tidal currents. Due to high concentrations of suspended particulate matter in the water column, light is rapidly attenuated, limiting macroal- gae production during part of the tidal cycle. An accurate representation of sediment dynamics is essential for the determination of the light energy available for the algae, which is a key factor in reliable primary production estimates. In tidal flats, the sedi- ment dynamics is made more complex by the formation of tidal pools during low tide, where water quickly becomes clear, allowing more light to penetrate through the water column. In the present work a model is developed to calculate macroalgae production in the intertidal areas of estuaries, considering the factors mentioned above. The model is tested for the Tagus estuary (Portugal), and a Gross Primary Production of 3300 g m-2 y-1 was obtained. That results in a total nitrogen removal of 440 gN m-2 y-1. The results show that the macroalgae community plays an impor- tant role in the nitrogen cycle in estuaries and nutrient export to the open sea, acting as a biorremediation for the increased nutrient loading problem.

  9. Comparing the impact of the 2003 and 2010 heatwaves on Net Ecosystem Production in Europe

    Science.gov (United States)

    Bastos, A. F.; Gouveia, C. M.; Trigo, R. M.

    2012-12-01

    Climate variability is known to influence primary productivity on land ecosystems (Nemani et al., 2003). In particular, extreme climatic events such as major droughts and heatwaves are known to have severe impact on primary productivity and, therefore, to affect significantly the carbon dioxide uptake by land ecosystems at regional (Ciais et al., 2005) or even global scale (Zhao and Running, 2010). In the last decade, Europe was struck by two outstanding heatwaves, the 2003 event in Western Europe and the recent 2010 episode over Eastern Europe. Both were characterised by record breaking temperatures at the daily, weekly, monthly and seasonal scales, although the amplitude and spatial extent of the 2010 mega-heatwave surpassed the 2003 event (Barriopedro et al., 2011). This work aims to assess the influence of both mega-heatwaves on seasonal and yearly Net Ecosystem Production (NEP). The work relies on monthly NEP data derived from satellite imagery obtained from MODIS (Moderate Resolution Imaging Spectroradiometer) sensor at 1km spatial resolution. Data were selected for the period between 2000 and 2011 over a region extending from 34.6 oN to 73.5 oN and 12.1 oW to 46.8 oE, covering Eurasia. In 2010 very low NEP anomalies are observed over a very large area in Eastern Europe, at the monthly, seasonal and yearly scale. In western Russia, yearly NEP anomalies fall below 50% of average cumulative NEP. These widespread negative anomalous values of NEP fields over the western Russia region match the patterns of very high temperature values combined with below-average precipitation, at the seasonal (summer) scale. Moreover, the impact of the heatwave is not only evident at the regional level but also at the wider continental (European) scale and is significantly more extensive and intense than the corresponding heatwave of 2003 in Western Europe (Ciais et al., 2005). References: Barriopedro, D., E. M. Fischer, J. Luterbacher, R. M. Trigo, and R. Garcia-Herrera (2011

  10. Enhancing the Feed Capacity of Horticulture Agro-Ecosystem Through Technology for Goat Production

    Directory of Open Access Journals (Sweden)

    Simon P Ginting

    2011-09-01

    Full Text Available The availability of feed and their efficiency of use throughout the year represent the most important constraint affecting the productivity of animals in any agro-ecosystems. Beside being the largest contributor to the total production cost, logistically feeds need to be available on a daily basis across the animal’s life time. In order to be competitive, goat production system must be directed toward the optimum utilization of inconventional feedstuffs such as crop residues and agro-industrial by-products. The horticulture crops provide various crop-residues and by products from the processing of its main products. These biomass are potential feedstuffs that could be used to support the production of goats. The processing of passion fruits (Passiflora edulis yield by products such as fruit shells and seeds. These products are good energy and protein sources for growing goats. Oriental radish (Raphanus sativus by-products composed by damaged root parts and culls have high digestible energy and low ether extract content, but have very high moisture content. The pineapple by-products composed by the peel and bagasse of the fruit could be used as energy source for goats. Other horticulture by-products or residues such as citrus pulp, abandoned citrus fruit, forages from Ipomea batatas are of great potential as feeds for goat production. Preserving technology like ensiling could be implemented in utilising those biomass categorized as wet by-products such as pineapple and oriental radish by-products. The technology of complete feed is an effective means in utilizing some of those products with relatively low palatability or to increase its inclusion level in diets. Introducing shade-tolerant forage species as intercrops such as Stenotaphrum secundatum, Brachiaria humidicola and Arachis pintoi in the citrus plantation should increase feed capacity of the area. The multi-purpose trees such as Indigofera sp. and Calliandra calothyrsus both are

  11. Biodiversity and Ecosystem Functioning: Exploring Principles of Ecology with Agricultural Plants

    Science.gov (United States)

    Ruesink, Jennifer; O'Connor, Eileen; Sparks, Grace

    2006-01-01

    To date, little of the ecological research on biological diversity and ecosystem functioning has been carried out in agricultural systems, despite the fact that agriculture is a major contributor to loss of native habitats and species. However, agricultural research has demonstrated that polycultures of multiple crop species can have higher total…

  12. Tree harvest in an experimental sand ecosystem: plant effects on nutrient dynamics and solute generation.

    Science.gov (United States)

    C. K. Keller; R. O' Brien; J. R. Havig; J. L. Smith; B. T. Bormann; D. Wang

    2006-01-01

    The hydrochemical signatures of forested ecosystems are known to be determined by a time-variant combination of physical-hydrologic, geochemical, and biologic processes. We studied subsurface potassium (K), calcium (Ca), and nitrate (NO3) in an experimental red-pine mesocosm to determine how trees affect the behavior of these nutrients in soil...

  13. Accounting for multiple stressors in regional stream ecosystem analysis: A demonstration with riparian invasive plants

    Science.gov (United States)

    Background/Questions/Methods: Large cross-sectional data sets allow testing of hypotheses about how one part of an ecosystem relates to other parts. Tests such as these are of interest for many reasons, one of which is to gain insight into the role of stressors, such as land co...

  14. Very high resolution time-lapse photography for plant and ecosystems research

    Science.gov (United States)

    Very high resolution gigapixel photography increasingly is being used to support a broad range of ecosystem and physical process research because it offers an inexpensive means of simultaneously collecting information at a range of spatial scales. Recently, methods have been developed to incorporate...

  15. Under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear?

    Science.gov (United States)

    Ye, Jian-Sheng; Pei, Jiu-Ying; Fang, Chao

    2018-03-01

    Understanding under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear is useful for accurately predicting the response of ecosystem function to global environmental change. Using long-term (2000-2016) net primary productivity (NPP)-precipitation datasets derived from satellite observations, we identify >5600pixels in the North Hemisphere landmass that fit either linear or nonlinear temporal NPP-precipitation relationships. Differences in climate (precipitation, radiation, ratio of actual to potential evapotranspiration, temperature) and soil factors (nitrogen, phosphorous, organic carbon, field capacity) between the linear and nonlinear types are evaluated. Our analysis shows that both linear and nonlinear types exhibit similar interannual precipitation variabilities and occurrences of extreme precipitation. Permutational multivariate analysis of variance suggests that linear and nonlinear types differ significantly regarding to radiation, ratio of actual to potential evapotranspiration, and soil factors. The nonlinear type possesses lower radiation and/or less soil nutrients than the linear type, thereby suggesting that nonlinear type features higher degree of limitation from resources other than precipitation. This study suggests several factors limiting the responses of plant productivity to changes in precipitation, thus causing nonlinear NPP-precipitation pattern. Precipitation manipulation and modeling experiments should combine with changes in other climate and soil factors to better predict the response of plant productivity under future climate. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Plant Design Nuclear Fuel Element Production Capacity Optimization to Support Nuclear Power Plant in Indonesia

    International Nuclear Information System (INIS)

    Bambang Galung Susanto

    2007-01-01

    The optimization production capacity for designing nuclear fuel element fabrication plant in Indonesia to support the nuclear power plant has been done. From calculation and by assuming that nuclear power plant to be built in Indonesia as much as 12 NPP and having capacity each 1000 MW, the optimum capacity for nuclear fuel element fabrication plant is 710 ton UO 2 /year. The optimum capacity production selected, has considered some aspects such as fraction batch (cycle, n = 3), length of cycle (18 months), discharge burn-up value (Bd) 35,000 up 50,000 MWD/ton U, enriched uranium to be used in the NPP (3.22 % to 4.51 %), future market development for fuel element, and the trend of capacity production selected by advances country to built nuclear fuel element fabrication plant type of PWR. (author)

  17. Concepts in production ecology for analysis and design of animal and plant-animal production systems

    NARCIS (Netherlands)

    Ven, van de G.W.J.; Ridder, de N.; Keulen, van H.; Ittersum, van M.K.

    2003-01-01

    The use of a hierarchy in growth factors (defining, limiting and reducing growth factors), as developed for plant production has shown its usefulness in the analysis and design of plant production systems. This hierarchy presents a theoretical framework for the analysis of biophysical conditions in

  18. Capabilities for managing high-volume production of electric engineering equipment at the Electrochemical Production Plant

    Energy Technology Data Exchange (ETDEWEB)

    Podlednev, V.M.

    1996-04-01

    The Electromechanical Production Plant is essentially a research center with experimental facilities and power full testing base. Major products of the plant today include heat pipes and devices of their basis of different functions and power from high temperature ranges to cryogenics. This report describes work on porous titanium and carbon-graphite current collectors, electrocatalyst synthesis, and electrocatalyst applications.

  19. Roots, plant production and nutrient use efficiency

    NARCIS (Netherlands)

    Willigen, de P.; Noordwijk, van M.

    1987-01-01

    The role of roots in obtaining high crop production levels as well as a high nutrient use efficiency is discussed. Mathematical models of diffusion and massflow of solutes towards roots are developed for a constant daily uptake requirement. Analytical solutions are given for simple and more

  20. Accumulation and environmental risk assessment of heavy metals in soil and plants of four different ecosystems in a former polymetallic ores mining and smelting area (Slovakia).

    Science.gov (United States)

    Demková, Lenka; Árvay, Július; Bobuľská, Lenka; Tomáš, Ján; Stanovič, Radovan; Lošák, Tomáš; Harangozo, Luboš; Vollmannová, Alena; Bystrická, Judita; Musilová, Janette; Jobbágy, Ján

    2017-04-16

    Heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in soils and plants of four different ecosystems (forest, grassland, agro and urban ecosystem) at different distances from the source of the pollution were analyzed in order to assess and compare soil contamination in the various ecosystems and determine the potential accumulation of plants depending on the place they inhabit. Correlation relationships among heavy metals in soils differ depending on the ecosystem, and between soil and plant, the heavy metals showed significant correlation for Cu, Mn, Ni, Pb and Zn. Contamination factor (C f ), degree of contamination (C d ) and pollution load index (PLI) were used in order to determine the level of environmental contamination of the study area. All studied ecosystems were rated as moderately contaminated (except agroecosystem, which was found as low contamination ecosystem) according to C d and extremely polluted according to PLI. The highest pollution in both cases was found in urban ecosystem, and Cd, Cu and Fe were determined as the biggest pollutants.

  1. Methods to Improve Survival and Growth of Planted Alternative Species Seedlings in Black Ash Ecosystems Threatened by Emerald Ash Borer

    Directory of Open Access Journals (Sweden)

    Nicholas Bolton

    2018-03-01

    Full Text Available Emerald ash borer (EAB continues to spread across North America, infesting native ash trees and changing the forested landscape. Black ash wetland forests are severely affected by EAB. As black ash wetland forests provide integral ecosystem services, alternative approaches to maintain forest cover on the landscape are needed. We implemented simulated EAB infestations in depressional black ash wetlands in the Ottawa National Forest in Michigan to mimic the short-term and long-term effects of EAB. These wetlands were planted with 10 alternative tree species in 2013. Based on initial results in the Michigan sites, a riparian corridor in the Superior Municipal Forest in Wisconsin was planted with three alternative tree species in 2015. Results across both locations indicate that silver maple (Acer saccharinum L., red maple (Acer rubrum L., American elm (Ulmus americana L., and northern white cedar (Thuja occidentalis L. are viable alternative species to plant in black ash-dominated wetlands. Additionally, selectively planting on natural or created hummocks resulted in two times greater survival than in adjacent lowland sites, and this suggests that planting should be implemented with microsite selection or creation as a primary control. Regional landowners and forest managers can use these results to help mitigate the canopy and structure losses from EAB and maintain forest cover and hydrologic function in black ash-dominated wetlands after infestation.

  2. Entropy production and plant transpiration in the Liz catchment

    Czech Academy of Sciences Publication Activity Database

    Šír, Miloslav; Tesař, Miroslav; Krejča, M.; Weger, J.

    2008-01-01

    Roč. 1, č. 1 (2008), s. 81-89 ISSN 1802-503X Grant - others:MŠMT(CZ) 2B06132 Institutional research plan: CEZ:AV0Z20600510 Keywords : plant transpiration * phytomass productivity * heat balance * entropy production Subject RIV: DA - Hydrology ; Limnology

  3. Impacts of droughts and extreme-temperature events on gross primary production and ecosystem respiration: a systematic assessment across ecosystems and climate zones

    Directory of Open Access Journals (Sweden)

    J. von Buttlar

    2018-03-01

    Full Text Available Extreme climatic events, such as droughts and heat stress, induce anomalies in ecosystem–atmosphere CO2 fluxes, such as gross primary production (GPP and ecosystem respiration (Reco, and, hence, can change the net ecosystem carbon balance. However, despite our increasing understanding of the underlying mechanisms, the magnitudes of the impacts of different types of extremes on GPP and Reco within and between ecosystems remain poorly predicted. Here we aim to identify the major factors controlling the amplitude of extreme-event impacts on GPP, Reco, and the resulting net ecosystem production (NEP. We focus on the impacts of heat and drought and their combination. We identified hydrometeorological extreme events in consistently downscaled water availability and temperature measurements over a 30-year time period. We then used FLUXNET eddy covariance flux measurements to estimate the CO2 flux anomalies during these extreme events across dominant vegetation types and climate zones. Overall, our results indicate that short-term heat extremes increased respiration more strongly than they downregulated GPP, resulting in a moderate reduction in the ecosystem's carbon sink potential. In the absence of heat stress, droughts tended to have smaller and similarly dampening effects on both GPP and Reco and, hence, often resulted in neutral NEP responses. The combination of drought and heat typically led to a strong decrease in GPP, whereas heat and drought impacts on respiration partially offset each other. Taken together, compound heat and drought events led to the strongest C sink reduction compared to any single-factor extreme. A key insight of this paper, however, is that duration matters most: for heat stress during droughts, the magnitude of impacts systematically increased with duration, whereas under heat stress without drought, the response of Reco over time turned from an initial increase to a downregulation after about 2 weeks. This confirms

  4. Heterologous production of peptides in plants: fusion proteins and beyond.

    Science.gov (United States)

    Viana, Juliane Flávia Cançado; Dias, Simoni Campos; Franco, Octávio Luiz; Lacorte, Cristiano

    2013-11-01

    Recombinant DNA technology has allowed the ectopic production of proteins and peptides of different organisms leading to biopharmaceutical production in large cultures of bacterial, yeasts and mammalian cells. Otherwise, the expression of recombinant proteins and peptides in plants is an attractive alternative presenting several advantages over the commonly used expression systems including reduced production costs, easy scale-up and reduced risks of pathogen contamination. Different types of proteins and peptides have been expressed in plants, including antibodies, antigens, and proteins and peptides of medical, veterinary and industrial applications. However, apart from providing a proof of concept, the use of plants as platforms for heterologous protein and peptide production still depends on key steps towards optimization including the enhancement of expression levels, manipulation of post-transcriptional modifications and improvements in purification methods. In this review, strategies to increase heterologous protein and peptide stability and accumulation are discussed, focusing on the expression of peptides through the use of gene fusions.

  5. Nutrient dynamics and primary production in a pristine coastal mangrove ecosystem: Andaman Islands, India

    Science.gov (United States)

    Jenkins, E. N.; Nickodem, K.; Siemann, A. L.; Hoeher, A.; Sundareshwar, P. V.; Ramesh, R.; Purvaja, R.; Banerjee, K.; Manickam, S.; Haran, H.

    2012-12-01

    Mangrove ecosystems play a key role in supporting coastal food webs and nutrient cycles in the coastal zone. Their strategic position between the land and the sea make them important sites for land-ocean interaction. As part of an Indo-US summer field course we investigated changes in the water chemistry in a pristine mangrove creek located at Wright Myo in the Andaman Islands, India. This study was conducted during the wet season (June 2012) to evaluate the influence of the coastal mangrove wetlands on the water quality and productivity in adjoining pelagic waters. Over a full tidal cycle spanning approximately 24 hrs, we measured nutrient concentrations and other ancillary parameters (e.g. dissolved oxygen, turbidity, salinity, etc.) hourly to evaluate water quality changes in incoming and ebbing tides. Nutrient analyses had the following concentration ranges (μM): nitrite 0.2-0.9, nitrate 2.0-11.5, ammonium 1.3-7.5, dissolved inorganic phosphate 0.7-2.8. The dissolved inorganic nitrogen to dissolved inorganic phosphate (DIN/DIP) ratio was very low relative to an optimal ratio, suggesting growth is nitrogen limited. In addition, we conducted primary production assays to investigate the factors that controlled primary production in this pristine creek. The experiment was carried out in situ using the Winkler method at low and high tide. Four-hour incubation of light and dark bottles representing a fixed control, non-fertilized, fertilized with nitrate, and fertilized with phosphate enabled the measurement of both net oxygen production and dark respiration. The low tide experiment suggests the ecosystem is heterotrophic because the oxygen measured in the light bottles was consistently less than that of the dark bottles. This result may be an experimental artifact of placing the glass bottles in the sun for too long prior to incubation, potentially leading to photolysis of large organic molecules in the light bottles. The high tide experiment also displayed

  6. Model calculation of radiocaesium transfer into food products in semi-natural forest ecosystems in the Czech Republic after a nuclear reactor accident and an estimate of the population dose burden

    International Nuclear Information System (INIS)

    Svadlenkova, M.; Konecny, J.; Smutny, V.

    1996-01-01

    Radioactivity of food products from semi-natural forest ecosystems can contribute appreciably to the radiological burden of the human population following a nuclear accident, as found after the Chernobyl disaster in 1986. In the Czech Republic, radiocaesium radioactivity has been measured, such as soil, mushrooms, bilberries, deer and boar. In this work, the data are employed to predict how a model accident of the Temelin nuclear power plant in southern Bohemia (which is under construction) would affect selected forest ecosystems in its surroundings. The dose commitment to the critical population group is also estimated. (author)

  7. Preferential Production and Transport of Grass-Derived Pyrogenic Carbon in NE-Australian Savanna Ecosystems

    Directory of Open Access Journals (Sweden)

    Gustavo Saiz

    2018-01-01

    Full Text Available Understanding the main factors driving fire regimes in grasslands and savannas is critical to better manage their biodiversity and functions. Moreover, improving our knowledge on pyrogenic carbon (PyC dynamics, including formation, transport and deposition, is fundamental to better understand a significant slow-cycling component of the global carbon cycle, particularly as these ecosystems account for a substantial proportion of the area globally burnt. However, a thorough assessment of past fire regimes in grass-dominated ecosystems is problematic due to challenges in interpreting the charcoal record of sediments. It is therefore critical to adopt appropriate sampling and analytical methods to allow the acquisition of reliable data and information on savanna fire dynamics. This study uses hydrogen pyrolysis (HyPy to quantify PyC abundance and stable isotope composition (δ13C in recent sediments across 38 micro-catchments covering a wide range of mixed C3/C4 vegetation in north Queensland, Australia. We exploited the contrasting δ13C values of grasses (i.e., C4; δ13C > −15‰ and woody vegetation (i.e., C3; δ13C < −24‰ to assess the preferential production and transport of grass-derived PyC in savanna ecosystems. Analyses were conducted on bulk and size-fractionated samples to determine the fractions into which PyC preferentially accumulates. Our data show that the δ13C value of PyC in the sediments is decoupled from the δ13C value of total organic carbon, which suggests that a significant component of PyC may be derived from incomplete grass combustion, even when the proportion of C4 grass biomass in the catchment was relatively small. Furthermore, we conducted 16 experimental burns that indicate that there is a comminution of PyC produced in-situ to smaller particles, which facilitates the transport of this material, potentially affecting its preservation potential. Savanna fires preferentially burn the grass understory rather than

  8. Drought footprint on European ecosystems between 1999 and 2010 assessed by remotely sensed vegetation phenology and productivity

    DEFF Research Database (Denmark)

    Ivits, Eva; Horion, Stéphanie Marie Anne F; Fensholt, Rasmus

    2014-01-01

    bioclimatic zones. The Standardized Precipitation and Evapotranspiration Index (SPEI) was used as drought indicator whereas changes in growing season length and vegetation productivity were assessed using remote sensing time-series of Normalized Difference Vegetation Index (NDVI). Drought spatio...... length, indicating that these ecosystems did not buffer the effects of drought well. In a climate change perspective, increase in drought frequency or intensity may result in larger impacts over these ecosystems, thus management and adaptation strategies should be strengthened in these areas of concerns.......Drought affects more people than any other natural disaster but there is little understanding of how ecosystems react to droughts. This study jointly analyzed spatio-temporal changes of drought patterns with vegetation phenology and productivity changes between 1999 and 2010 in major European...

  9. Biodegradable bags for the production of plant seedlings

    Directory of Open Access Journals (Sweden)

    Ana Paula Bilck

    2014-10-01

    Full Text Available The production of plant seedlings has traditionally used polyethylene bags, which are thrown out in the soil or burned after transplant because the large amount of organic material attached to the bags makes recycling difficult. Additionally, when a seedling is taken from the bag for transplant, there is the risk of root damage, which compromises the plant’s development. In this study, we developed biodegradable bags to be used in seedling production, and we verify their influence on the development of Brazilian ginseng (Pfaffia glomerata (Spreng Pedersen, when the plant is planted without being removed from the bag. Both black and white biodegradable bags remained intact throughout the seedling production period (60 days. After being transplanted into containers (240 days, they were completely biodegraded, and there was no significant difference between the dry mass of these plants and that of plants that were transplanted without the bags. The plants that were cultivated without being removed from the polyethylene bags had root development difficulties, and the wrapping showed no signs of degradation. The use of biodegradable films is an alternative for the production of bags for seedlings, as these can then be transplanted directly into the soil without removing the bag, reducing the risk of damage to the roots during the moment of transplant.

  10. Innovative applications of technology for nuclear power plant productivity improvements

    International Nuclear Information System (INIS)

    Naser, J. A.

    2012-01-01

    The nuclear power industry in several countries is concerned about the ability to maintain high plant performance levels due to aging and obsolescence, knowledge drain, fewer plant staff, and new requirements and commitments. Current plant operations are labor-intensive due to the vast number of operational and support activities required by commonly used technology in most plants. These concerns increase as plants extend their operating life. In addition, there is the goal to further improve performance while reducing human errors and increasingly focus on reducing operations and maintenance costs. New plants are expected to perform more productively than current plants. In order to achieve and increase high productivity, it is necessary to look at innovative applications of modern technologies and new concepts of operation. The Electric Power Research Inst. is exploring and demonstrating modern technologies that enable cost-effectively maintaining current performance levels and shifts to even higher performance levels, as well as provide tools for high performance in new plants. Several modern technologies being explored can provide multiple benefits for a wide range of applications. Examples of these technologies include simulation, visualization, automation, human cognitive engineering, and information and communications technologies. Some applications using modern technologies are described. (authors)

  11. Constraining Ecosystem Gross Primary Production and Transpiration with Measurements of Photosynthetic 13CO2 Discrimination

    Science.gov (United States)

    Blonquist, J. M.; Wingate, L.; Ogeé, J.; Bowling, D. R.

    2011-12-01

    The stable carbon isotope composition of atmospheric CO2 (δ13Ca) can provide useful information on water use efficiency (WUE) dynamics of terrestrial ecosystems and potentially constrain models of CO2 and water fluxes at the land surface. This is due to the leaf-level relationship between photosynthetic 13CO2 discrimination (Δ), which influences δ13Ca, and the ratio of leaf intercellular to atmospheric CO2 mole fractions (Ci / Ca), which is related to WUE and is determined by the balance between C assimilation (CO2 demand) and stomatal conductance (CO2 supply). We used branch-scale Δ derived from tunable diode laser absorption spectroscopy measurements collected in a Maritime pine forest to estimate Ci / Ca variations over an entire growing season. We combined Ci / Ca estimates with rates of gross primary production (GPP) derived from eddy covariance (EC) to estimate canopy-scale stomatal conductance (Gs) and transpiration (T). Estimates of T were highly correlated to T estimates derived from sapflow data (y = 1.22x + 0.08; r2 = 0.61; slope P MuSICA) (y = 0.88x - 0.05; r2 = 0.64; slope P MuSICA (y = 1.10 + 0.42; r2 = 0.50; slope P < 0.001). Results demonstrate that the leaf-level relationship between Δ and Ci / Ca can be extended to the canopy-scale and that Δ measurements have utility for partitioning ecosystem-scale CO2 and water fluxes.

  12. Successional changes in live and dead wood carbon stores: implications for net ecosystem productivity.

    Science.gov (United States)

    Janisch, J E; Harmon, M E

    2002-02-01

    If forests are to be used in CO2 mitigation projects, it is essential to understand and quantify the impacts of disturbance on net ecosystem productivity (NEP; i.e., the change in ecosystem carbon (C) storage with time). We examined the influence of live tree and coarse woody debris (CWD) on NEP during secondary succession based on data collected along a 500-year chronosequence on the Wind River Ranger District, Washington. We developed a simple statistical model of live and dead wood accumulation and decomposition to predict changes in the woody component of NEP, which we call NEP(w). The transition from negative to positive NEP(w), for a series of scenarios in which none to all wood was left after disturbance, occurred between 0 and 57 years after disturbance. The timing of this transition decreased as live-tree growth rates increased, and increased as CWD left after disturbance increased. Maximum and minimum NEP(w) for all scenarios were 3.9 and -14.1 Mg C ha-1 year-1, respectively. Maximum live and total wood C stores of 319 and 393 Mg C ha(-1), respectively, were reached approximately 200 years after disturbance. Decomposition rates (k) of CWD ranged between 0.013 and 0.043 year-1 for individual stands. Regenerating stands took 41 years to attain a mean live wood mass equivalent to the mean mass of CWD left behind after logging, 40 years to equal the mean CWD mass in 500-year-old forest, and more than 150 years to equal the mean total live and dead wood in an old-growth stand. At a rotation age of 80 years, regenerating stands stored approximately half the wood C of the remaining nearby old-growth forests (predominant age 500 years), indicating that conversion of old-growth forests to younger managed forests results in a significant net release of C to the atmosphere.

  13. Biological effects of carbon nanotubes generated in forest wildfire ecosystems rich in resinous trees on native plants

    Directory of Open Access Journals (Sweden)

    Javier Lara-Romero

    2017-08-01

    Full Text Available Carbon nanotubes (CNTs have a broad range of applications and are generally considered human-engineered nanomaterials. However, carbon nanostructures have been found in ice cores and oil wells, suggesting that nature may provide appropriate conditions for CNT synthesis. During forest wildfires, materials such as turpentine and conifer tissues containing iron under high temperatures may create chemical conditions favorable for CNT generation, similar to those in synthetic methods. Here, we show evidence of naturally occurring multiwalled carbon nanotubes (MWCNTs produced from Pinus oocarpa and Pinus pseudostrobus, following a forest wildfire. The MWCNTs showed an average of 10 walls, with internal diameters of ∼2.5 nm and outer diameters of ∼14.5 nm. To verify whether MWCNT generation during forest wildfires has a biological effect on some characteristic plant species of these ecosystems, germination and development of seedlings were conducted. Results show that the utilization of comparable synthetic MWCNTs increased seed germination rates and the development of Lupinus elegans and Eysenhardtia polystachya, two plants species found in the burned forest ecosystem. The finding provides evidence that supports the generation and possible ecological functions of MWCNTs in nature.

  14. Dominant role of plant physiology in trend and variability of gross primary productivity in North America

    Science.gov (United States)

    Zhou, Sha; Zhang, Yao; Ciais, Philippe; Xiao, Xiangming; Luo, Yiqi; Caylor, Kelly K.; Huang, Yuefei; Wang, Guangqian

    2017-02-01

    Annual gross primary productivity (GPP) varies considerably due to climate-induced changes in plant phenology and physiology. However, the relative importance of plant phenology and physiology on annual GPP variation is not clear. In this study, a Statistical Model of Integrated Phenology and Physiology (SMIPP) was used to evaluate the relative contributions of maximum daily GPP (GPPmax) and the start and end of growing season (GSstart and GSend) to annual GPP variability, using a regional GPP product in North America during 2000-2014 and GPP data from 24 AmeriFlux sites. Climatic sensitivity of the three indicators was assessed to investigate the climate impacts on plant phenology and physiology. The SMIPP can explain 98% of inter-annual variability of GPP over mid- and high latitudes in North America. The long-term trend and inter-annual variability of GPP are dominated by GPPmax both at the ecosystem and regional scales. During warmer spring and autumn, GSstart is advanced and GSend delayed, respectively. GPPmax responds positively to summer temperature over high latitudes (40-80°N), but negatively in mid-latitudes (25-40°N). This study demonstrates that plant physiology, rather than phenology, plays a dominant role in annual GPP variability, indicating more attention should be paid to physiological change under futher climate change.

  15. Plant growth promotion rhizobacteria in onion production.

    Science.gov (United States)

    Colo, Josip; Hajnal-Jafari, Timea I; Durić, Simonida; Stamenov, Dragana; Hamidović, Saud

    2014-01-01

    The aim of the research was to examine the effect of rhizospheric bacteria Azotobacter chroococcum, Pseudomonas fluorescens (strains 1 and 2) and Bacillus subtilis on the growth and yield of onion and on the microorganisms in the rhizosphere of onion. The ability of microorganisms to produce indole-acetic acid (IAA), siderophores and to solubilize tricalcium phosphate (TCP) was also assessed. The experiment was conducted in field conditions, in chernozem type of soil. Bacillus subtilis was the best producer of IAA, whereas Pseudomonas fluorescens strains were better at producing siderophores and solubilizing phosphates. The longest seedling was observed with the application of Azotobacter chroococcum. The height of the plants sixty days after sowing was greater in all the inoculated variants than in the control. The highest onion yield was observed in Bacillus subtilis and Azotobacter chroococcum variants. The total number of bacteria and the number of Azotobacter chroococcum were larger in all the inoculated variants then in the control. The number of fungi decreased in most of the inoculated variants, whereas the number of actinomycetes decreased or remained the same.

  16. Prosopis laevigata and Mimosa biuncifera (Leguminosae, jointly influence plant diversity and soil fertility of a Mexican semiarid ecosystem

    Directory of Open Access Journals (Sweden)

    Rosalva García-Sánchez

    2012-03-01

    Full Text Available Prosopis laevigata and Mimosa biuncifera are frequently found in arid and semiarid shrublands, but scarce information is available about their influence on plant community structure and soil fertility. We compared plant community structure, diversity and soil nutrients of three semiarid shrubland sites located in Mezquital Valley, Mexico. These sites differ in their dominant species: Site 1 (Bingu P. laevigata, Site 2 (González M. biuncifera, and Site 3 (Rincón with the presence of both legumes. The results showed that the plant community with P. laevigata and M. biuncifera (Site 3 had more cover, taller plants and higher plant diversity than sites with only one legume (Site 1 and Site 2. Soil organic matter (SOM, soil organic carbon (SOC, total nitrogen (TN, phosphorus-Olsen (P and C mineralization were higher in the soil under the canopy of both legumes than in bare soil. In contrast, soil cation concentrations were lower under the canopy of P. laevigata, but not for M. biuncifera. In addition, the density of arbuscular mycorrhizal fungi spores was higher within the soil under the canopy of M. biuncifera than in the soil under the canopy of P. laevigata. Thus, resource islands (RI created by P. laevigata increased the amounts of SOC, TN and P when compared with the RI of M. biuncifera. This study provided evidences about the importance of species identity in order to expand the niche availability for the establishment of other plants, and highlights that P. laevigata and M. biuncifera jointly influencing plant colonization within semiarid ecosystems

  17. Links between plant litter chemistry, species diversity, and below-ground ecosystem function

    OpenAIRE

    Meier, Courtney L.; Bowman, William D.

    2008-01-01

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics...

  18. The biotest basin of the Forsmark nuclear power plant, Sweden. An experiment on the ecosystem level

    International Nuclear Information System (INIS)

    Grimaas, U.

    1979-01-01

    Biotope models of various sizes and enclosed waters in connection with radionuclide release constitute important tools for radioecological experiments, representing an intermediate step between field and laboratory conditions. The biotest basin at Forsmark is especially constructed for investigations on the effects of radioactivity and heat on a brackish water ecosystem. The basin encloses a water area of 1km 2 in the outer archipelago of the region and is fed with cooling water and released radionuclides by a discharge tunnel. The quantities of the discharges into the basin are adjustable. The biotest experiment permits a quantification of the retention and transport of radionuclides at the various trophic levels. Of special value is the possibility to work with known populations of fish. The approach has the advantage of experimental ecology - the control of important parameters - under the impact of all environmental factors in a complete ecosystem. (author)

  19. Modelling energy consumption in a manufacturing plant using productivity KPIs

    Energy Technology Data Exchange (ETDEWEB)

    Gallachoir, Brian O.; Cahill, Caiman (Sustainable Energy Research Group, Dept. of Civil and Environmental Engineering, Univ. College Cork (Ireland))

    2009-07-01

    Energy efficiency initiatives in industrial plants are often focused on getting energy-consuming utilities and devices to operate more efficiently, or on conserving energy. While such device-oriented energy efficiency measures can achieve considerable savings, greater energy efficiency improvement may be achieved by improving the overall productivity and quality of manufacturing processes. The paper highlights the observed relationship between productivity and energy efficiency using aggregated data on unit consumption and production index data for Irish industry. Past studies have developed simple top-down models of final energy consumption in manufacturing plants using energy consumption and production output figures, but these models do not help identify opportunities for energy savings that could achieved through increased productivity. This paper proposes an improved and innovative method of modelling plant final energy demand that introduces standard productivity Key Performance Indicators (KPIs) into the model. The model demonstrates the relationship between energy consumption and productivity, and uses standard productivity metrics to identify the areas of manufacturing activity that offer the most potential for improved energy efficiency. The model provides a means of comparing the effect of device-oriented energy efficiency measures with the potential for improved energy efficiency through increased productivity.

  20. Crop production and economic loss due to wind erosion in hot arid ecosystem of India

    Science.gov (United States)

    Santra, Priyabrata; Moharana, P. C.; Kumar, Mahesh; Soni, M. L.; Pandey, C. B.; Chaudhari, S. K.; Sikka, A. K.

    2017-10-01

    Wind erosion is a severe land degradation process in hot arid western India and affects the agricultural production system. It affects crop yield directly by damaging the crops through abrasion, burial, dust deposition etc. and indirectly by reducing soil fertility. In this study, an attempt was made to quantify the indirect impact of wind erosion process on crop production loss and associated economic loss in hot arid ecosystem of India. It has been observed that soil loss due to wind erosion varies from minimum 1.3 t ha-1 to maximum 83.3 t ha-1 as per the severity. Yield loss due to wind erosion was found maximum for groundnut (Arachis hypogea) (5-331 kg ha-1 yr-1), whereas minimum for moth bean (Vigna aconitifolia) (1-93 kg ha-1 yr-1). For pearl millet (Pennisetum glaucum), which covers a major portion of arable lands in western Rajasthan, the yield loss was found 3-195 kg ha-1 yr-1. Economic loss was found higher for groundnut and clusterbean (Cyamopsis tetragonoloba) than rest crops, which are about

  1. Computing the net primary productivity for a savannah-dominated ecosystem using stable isotopes: a case study of the Volta River Basin

    International Nuclear Information System (INIS)

    Hayford, E.K.

    2008-01-01

    The hydrologic systems and the terrestrial ecosystem of the Volta river basin in West Africa, play important role in the carbon cycle. This is so because of the coupling of water vapour release and CO 2 uptake during photosynthesis, expressed as water use efficiency or transpiration ratio. Hydrologic and land-cover data, together with stable isotope ratio measurements of δ 18 O and δD, and data from the global network of isotopes in precipitation (GNIP) are used to determine the net primary productivity (NPP) of the Savannah-dominated ecosystem. The δ 18 O and δD values in the Volta rivers range from -4.72 to 2.37 mm -l and from -35.28 to 9.30 mm -1 SMOW, respectively. The results indicate that the vegetation is supported by 380 km 3 of rainfall, out of which 50% is returned to the atmosphere via plant transpiration. Associated with annual transpiration is the NPP of 0.170 x 10 15 gCyr -1 or 428 gCm -2 from the terrestrial ecosystem. Modelled estimates of heterotrophic soil respiration in this study slightly exceeded the NPP estimates, implying a small source of CO 2 to the atmosphere. This condition does not favour the postulated existence of a major sink of atmospheric CO 2 in the Volta basin. (au)

  2. Integrating ecosystem services into crop protection and pest management: Case study with the soil fumigant 1,3-dichloropropene and its use in tomato production in Italy.

    Science.gov (United States)

    Deacon, Samantha; Alix, Anne; Knowles, Steve; Wheeler, James; Tescari, Enzo; Alvarez, Lara; Nicolette, Joseph; Rockel, Mark; Burston, Peter; Quadri, Giorgia

    2016-10-01

    Ecosystems provide the conditions for producing food, regulating water, and providing wildlife habitats; these, among others, are known as ecosystem services (ESs). Food production is both economically and culturally important to southern European farmers, particularly in Italy where farmers grow flavorsome tomatoes with passion and pride. Growers rely on pesticides for crop protection, the potential environmental impact of which is often questioned by regulators and other stakeholders. The European regulatory system for the approval of pesticides includes a thorough evaluation of risks to the environment and is designed to be protective of ecosystems. The consideration of ESs in environmental decision making is a growing trend, and the present case study provides an example of how ESs evaluation could be used to enhance agricultural practices and regulatory policy for crop protection. By attacking plant roots, nematodes may affect the growth and yield of fruit and vegetable crops, and the income earned by farmers at harvest time. Available solutions include chemical treatments such as 1,3-dichloropropene (1,3-D), physical treatments (solarization), and biological treatments (biofumigation). In order to characterize the risks and benefits associated with the use of 1,3-D in crop protection, ESs and socioeconomic analyses were applied to its use in the control of nematodes in tomato cultivation in southern Italy. The present study confirmed the benefits of 1,3-D to tomato production in Italy, with significant positive effects on production yields and farm income when compared to limited and transient potential impacts on services such as soil function. It was confirmed that 1,3-D allows farm income to be maintained and secures tomato production in these regions for the future. Integr Environ Assess Manag 2016;12:801-810. © 2016 SETAC. © 2016 SETAC.

  3. Understanding the value of plant diversity for ecosystem functioning through niche theory

    Science.gov (United States)

    Isbell, Forest; Purves, Drew W.; Loreau, Michel

    2016-01-01

    Biodiversity experiments have generated robust empirical results supporting the hypothesis that ecosystems function better when they contain more species. Given that ecosystems provide services that are valued by humans, this inevitably suggests that the loss of species from natural ecosystems could diminish their value. This raises two important questions. First, will experimental results translate into the real world, where species are being lost at an alarming rate? And second, what are the benefits and pitfalls of such valuation exercises? We argue that the empirical results obtained in experiments are entirely consistent with well-established theories of species coexistence. We then examine the current body of work through the lens of niche theory and highlight where closer links with theory could open up opportunities for future research. We argue that niche theory predicts that diversity–functioning relationships are likely to be stronger (and require more species) in the field than in simplified experimental settings. However, we caution that while many of the biological processes that promote coexistence can also generate diversity–function relationships, there is no simple mapping between the two. This implies that valuation exercises need to proceed with care. PMID:27928043

  4. Accumulation and transfer of 1