Problem of industrial fumes in the forested valleys of Savoy

Energy Technology Data Exchange (ETDEWEB)

Bossavy, J

1962-01-01

A study of injury to forest trees in the Maurienne valley, caused by F in the fumes from aluminum factories was made. Of the local conifers, Pinus sylvestris was the most susceptible, followed by Picea abies and Abies alba; Larch has so far proved resistant, as have broadleaved deciduous species.

The role of novel forest ecosystems in the conservation of wood-inhabiting fungi in boreal broadleaved forests.

Science.gov (United States)

Juutilainen, Katja; Mönkkönen, Mikko; Kotiranta, Heikki; Halme, Panu

2016-10-01

The increasing human impact on the earth's biosphere is inflicting changes at all spatial scales. As well as deterioration and fragmentation of natural biological systems, these changes also led to other, unprecedented effects and emergence of novel habitats. In boreal zone, intensive forest management has negatively impacted a multitude of deadwood-associated species. This is especially alarming given the important role wood-inhabiting fungi have in the natural decay processes. In the boreal zone, natural broad-leaved-dominated, herb-rich forests are threatened habitats which have high wood-inhabiting fungal species richness. Fungal diversity in other broadleaved forest habitat types is poorly known. Traditional wood pastures and man-made afforested fields are novel habitats that could potentially be important for wood-inhabiting fungi. This study compares species richness and fungal community composition across the aforementioned habitat types, based on data collected for wood-inhabiting fungi occupying all deadwood diameter fractions. Corticioid and polyporoid fungi were surveyed from 67 130 deadwood particles in four natural herb-rich forests, four birch-dominated wood pastures, and four birch-dominated afforested field sites in central Finland. As predicted, natural herb-rich forests were the most species-rich habitat. However, afforested fields also had considerably higher overall species richness than wood pastures. Many rare or rarely collected species were detected in each forest type. Finally, fungal community composition showed some divergence not only among the different habitat types, but also among deadwood diameter fractions. Synthesis and applications : In order to maintain biodiversity at both local and regional scales, conserving threatened natural habitat types and managing traditional landscapes is essential. Man-made secondary woody habitats could provide the necessary resources and serve as surrogate habitats for many broadleaved deadwood

Mapping forest functional type in a forest-shrubland ecotone using SPOT imagery and predictive habitat distribution modelling

Science.gov (United States)

Assal, Timothy J.; Anderson, Patrick J.; Sibold, Jason

2015-01-01

The availability of land cover data at local scales is an important component in forest management and monitoring efforts. Regional land cover data seldom provide detailed information needed to support local management needs. Here we present a transferable framework to model forest cover by major plant functional type using aerial photos, multi-date Système Pour l’Observation de la Terre (SPOT) imagery, and topographic variables. We developed probability of occurrence models for deciduous broad-leaved forest and needle-leaved evergreen forest using logistic regression in the southern portion of the Wyoming Basin Ecoregion. The model outputs were combined into a synthesis map depicting deciduous and coniferous forest cover type. We evaluated the models and synthesis map using a field-validated, independent data source. Results showed strong relationships between forest cover and model variables, and the synthesis map was accurate with an overall correct classification rate of 0.87 and Cohen’s kappa value of 0.81. The results suggest our method adequately captures the functional type, size, and distribution pattern of forest cover in a spatially heterogeneous landscape.

[Effects of selective cutting on soil phosphorus forms and availability in Korean pine broad-leaved forest in Xiaoxing'an Mountains of China.

Science.gov (United States)

Zhang, Xin; Gu, Hui Yan; Chen, Xiang Wei

2018-02-01

In order to clarify the effects of selective cutting on soil phosphorus availability in Korean pine broad-leaved forest, surface soil (0-10 cm) samples from original Korean pine broad-leaved forest and natural forests with mild, medium and intensive cutting disturbances were collected. The Sui modified Hedley phosphorus fractionation method was used to continuously extract soil samples and analyzed the differences and changes of soil phosphorus fractions from different experimental stands. The results showed that the soil total phosphorus content of Korean pine broad-leaved forest varied from 1.09 to 1.66 g·kg -1 , with the original stand and intensive cutting disturbance stand being the maximum and minimum one, respectively. The differences of soil total phosphorus content among cutting disturbance levels were significant. The Olsen phosphorus and phosphorus activation coefficients changed with an amplitude of 7.26-17.79 mg·kg -1 and 0.67%-1.07%, respectively. Both of them significantly decreased with the increase of selective cutting disturbance level. The concentrations of all P fractions except HCl-P o , i.e., H 2 O-P i , NaHCO 3 -P, NaOH-P, HCl-P i , Residual-P, decreased with increasing cutting disturbance levels compared with original forest. The correlation coefficient between H 2 O-P i and soil Olsen phosphorus was the highest (0.98), though it only accounted for 1.5%-2.2% of the total phosphorus. NaOH-P content contributed to more than 48.0% of the total phosphorus, acknowledged as the potential source of soil phosphorus. In conclusion, selective cutting disturbance could constrain phosphorus storage and soil phosphorus availabi-lity of the Korean pine broad-leaved forests by significantly reducing the content of soil inorganic phosphorus and NaOH-P o , and such trends were positively dependent on the intensity of selective cutting.

[Microelement contents of litter, soil fauna and soil in Pinus koraiensis and broad-leaved mixed forest].

Science.gov (United States)

Yin, Xiu-qin; Li, Jin-xia; Dong, Wei-hua

2007-02-01

The analysis on the Mn, Zn and Cu contents of litter, soil fauna and soil in Pinus korazenszis and broad-leaved mixed forest in Liangshui Natural Reserve of Xiaoxing' an Mountains showed that the test microelement contents in the litter, soil fauna and soil all followed the sequence of Mn > Zn > Cu, but varied with these environmental components, being in the sequence of soil > litter > soil fauna for Mn, soil fauna > litter and soil for Zn, and soil fauna > soil > litter for Cu. The change range of test microelement contents in litter was larger in broad-leaved forest than in coniferous forest. Different soil fauna differed in their microelement-enrichment capability, e. g. , earthworm, centipede, diplopod had the highest content of Mn, Zn and Cu, respectively. The contents of test microelements in soil fauna had significant correlations with their environmental background values, litter decomposition rate, food habit of soil fauna, and its absorbing selectivity and enrichment to microelements. The microelements contained in 5-20 cm soil layer were more than those in 0-5 cm soil layer, and their dynamics differed in various soil layers.

Deciduous forest responses to temperature, precipitation, and drought imply complex climate change impacts.

Science.gov (United States)

Xie, Yingying; Wang, Xiaojing; Silander, John A

2015-11-03

Changes in spring and autumn phenology of temperate plants in recent decades have become iconic bio-indicators of rapid climate change. These changes have substantial ecological and economic impacts. However, autumn phenology remains surprisingly little studied. Although the effects of unfavorable environmental conditions (e.g., frost, heat, wetness, and drought) on autumn phenology have been observed for over 60 y, how these factors interact to influence autumn phenological events remain poorly understood. Using remotely sensed phenology data from 2001 to 2012, this study identified and quantified significant effects of a suite of environmental factors on the timing of fall dormancy of deciduous forest communities in New England, United States. Cold, frost, and wet conditions, and high heat-stress tended to induce earlier dormancy of deciduous forests, whereas moderate heat- and drought-stress delayed dormancy. Deciduous forests in two eco-regions showed contrasting, nonlinear responses to variation in these explanatory factors. Based on future climate projection over two periods (2041-2050 and 2090-2099), later dormancy dates were predicted in northern areas. However, in coastal areas earlier dormancy dates were predicted. Our models suggest that besides warming in climate change, changes in frost and moisture conditions as well as extreme weather events (e.g., drought- and heat-stress, and flooding), should also be considered in future predictions of autumn phenology in temperate deciduous forests. This study improves our understanding of how multiple environmental variables interact to affect autumn phenology in temperate deciduous forest ecosystems, and points the way to building more mechanistic and predictive models.

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

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Hiroki Itô

2016-12-01

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

Simulation of regional temperature change effect of land cover change in agroforestry ecotone of Nenjiang River Basin in China

Science.gov (United States)

Liu, Tingxiang; Zhang, Shuwen; Yu, Lingxue; Bu, Kun; Yang, Jiuchun; Chang, Liping

2017-05-01

The Northeast China is one of typical regions experiencing intensive human activities within short time worldwide. Particularly, as the significant changes of agriculture land and forest, typical characteristics of pattern and process of agroforestry ecotone change formed in recent decades. The intensive land use change of agroforestry ecotone has made significant change for regional land cover, which had significant impact on the regional climate system elements and the interactions among them. This paper took agroforestry ecotone of Nenjiang River Basin in China as study region and simulated temperature change based on land cover change from 1950s to 1978 and from 1978 to 2010. The analysis of temperature difference sensitivity to land cover change based on Weather Research and Forecasting (WRF) model showed that the land cover change from 1950s to 1978 induced warming effect over all the study area, including the change of grassland to agriculture land, grassland to deciduous broad-leaved forest, and deciduous broad-leaved forest to shrub land. The land cover change from 1978 to 2010 induced cooling effect over all the study area, including the change of deciduous broad-leaved forest to agriculture land, grassland to agriculture land, shrub land to agriculture land, and deciduous broad-leaved forest to grassland. In addition, the warming and cooling effect of land cover change was more significant in the region scale than specific land cover change area.

A climate change-induced threat to the ecological resilience of a subtropical monsoon evergreen broad-leaved forest in Southern China.

Science.gov (United States)

Zhou, Guoyi; Peng, Changhui; Li, Yuelin; Liu, Shizhong; Zhang, Qianmei; Tang, Xuli; Liu, Juxiu; Yan, Junhua; Zhang, Deqiang; Chu, Guowei

2013-04-01

Recent studies have suggested that tropical forests may not be resilient against climate change in the long term, primarily owing to predicted reductions in rainfall and forest productivity, increased tree mortality, and declining forest biomass carbon sinks. These changes will be caused by drought-induced water stress and ecosystem disturbances. Several recent studies have reported that climate change has increased tree mortality in temperate and boreal forests, or both mortality and recruitment rates in tropical forests. However, no study has yet examined these changes in the subtropical forests that account for the majority of China's forested land. In this study, we describe how the monsoon evergreen broad-leaved forest has responded to global warming and drought stress using 32 years of data from forest observation plots. Due to an imbalance in mortality and recruitment, and changes in diameter growth rates between larger and smaller trees and among different functional groups, the average DBH of trees and forest biomass have decreased. Sap flow measurements also showed that larger trees were more stressed than smaller trees by the warming and drying environment. As a result, the monsoon evergreen broad-leaved forest community is undergoing a transition from a forest dominated by a cohort of fewer and larger individuals to a forest dominated by a cohort of more and smaller individuals, with a different species composition, suggesting that subtropical forests are threatened by their lack of resilience against long-term climate change. © 2012 Blackwell Publishing Ltd.

[Organic carbon and carbon mineralization characteristics in nature forestry soil].

Science.gov (United States)

Yang, Tian; Dai, Wei; An, Xiao-Juan; Pang, Huan; Zou, Jian-Mei; Zhang, Rui

2014-03-01

Through field investigation and indoor analysis, the organic carbon content and organic carbon mineralization characteristics of six kinds of natural forest soil were studied, including the pine forests, evergreen broad-leaved forest, deciduous broad-leaved forest, mixed needle leaf and Korean pine and Chinese pine forest. The results showed that the organic carbon content in the forest soil showed trends of gradual decrease with the increase of soil depth; Double exponential equation fitted well with the organic carbon mineralization process in natural forest soil, accurately reflecting the mineralization reaction characteristics of the natural forest soil. Natural forest soil in each layer had the same mineralization reaction trend, but different intensity. Among them, the reaction intensity in the 0-10 cm soil of the Korean pine forest was the highest, and the intensities of mineralization reaction in its lower layers were also significantly higher than those in the same layers of other natural forest soil; comparison of soil mineralization characteristics of the deciduous broad-leaved forest and coniferous and broad-leaved mixed forest found that the differences of litter species had a relatively strong impact on the active organic carbon content in soil, leading to different characteristics of mineralization reaction.

The principles for creation of fire-prevention forest belts with barriers of deciduous species for protection from crown fires

Directory of Open Access Journals (Sweden)

S. N. Sannikov

2017-10-01

Full Text Available The article discuss one of the priority security problems in Russia, which is elaboration of the strategic system of the forest and society safeguards from catastrophic forest crown fires in connection with rapid climate warming. It is postulated, that a most effective and reliable barrier for the dispersal of the intensive crown fire in a coniferous forest massive can be a sufficiently wide strip of deciduous tree species – «deciduous forest barrier», which has phytomass capable of absorbing crown fire energy and transforming them to surface fire, which may be extinguished by technical means. The actuality of the natural study of the transition parameters from the crown fire to surface fire has been noted, depending on climate, fire intensity and the deciduous barrier structure. The results of the quantitative natural investigation of the consequences of catastrophic crown fires of 2004 in the island pine forests of forest-steppe zone in Kurgan Oblast, which passed through the belt of 50–70 year-old birch stands of middle density, has been cited and formalized mathematically. It has been shown, that 150 m width of deciduous forest barrier is necessary as a minimum for the reliable transition of the high intensive front crown fire to surface fire in the forest-steppe conditions of the Western Siberia, but this width reduces with a decreasing heating effect. It has been proposed to create the complex fire-prevention forest belts of different construction for the protection of forests, industrial objects and settlements. Besides a basic deciduous barrier, their structure should include technologically necessary buffer zones and zones for the localization and extinguishing surface fire, which stop a crown fire. It has been recommended to use natural regeneration of deciduous tree species, as a most effective and non-deficient method for the creation of deciduous forest barriers in the predominant forest types, except the lichen pine forests

Functional role of the herbaceous layer in eastern deciduous forest

Science.gov (United States)

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

2014-01-01

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

Arthropod vertical stratification in temperate deciduous forests: Implications for conservation oriented management

Science.gov (United States)

Ulyshen Michael

2011-01-01

Studies on the vertical distribution patterns of arthropods in temperate deciduous forests reveal highly stratified (i.e., unevenly vertically distributed) communities. These patterns are determined by multiple factors acting simultaneously, including: (1) time (forest age, season, time of day); (2) forest structure (height, vertical foliage complexity, plant surface...

Forest vegetation of Xishuangbanna, south China

Institute of Scientific and Technical Information of China (English)

Zhu Hua

2006-01-01

Xishuangbanna of southern Yunnan is biogeographically located at a transitional zone from tropical southeast (SE) Asia to subtropical east Asia and is at the junction of the Indian and Burmese plates of Gondwana and the Eurasian plate of Laurasia. The region, though surprisingly far from the equator and at a relatively high altitude, has a rich tropical flora and a typical tropical rain forest in the lowland areas. Based on physiognomic and ecological characteristics, floristic composition and habitats combined, the primary vegetation in Xishuangbanna can be organized into four main vegetation types: tropical rain forest, tropical seasonal moist forest, tropical montane evergreen broad-leaved forest and tropical monsoon forest. The tropical rain forest can be classified into two subtypes, i.e. a tropical seasonal rain forest in the lowlands and a tropical montane rain forest at higher elevations. The tropical seasonal rain forest has almost the same forest profile and physiognomic characteristics as equatorial lowland rain forests and is a type of truly tropical rain forest. Because of conspicuous similarity on ecological and floristic characteristics, the tropical rain forest in Xishuangbanna is a type of tropical Asian rain forest. However, since the tropical rain forest of Xishuangbanna occurs at the northern edge of tropical SE Asia, it differs from typical lowland rain forests in equatorial areas in having some deciduous trees in the canopy layer, fewer megaphanerophytes and epiphytes but more abundant lianas and more plants with microphyll. It is a type of semi-evergreen rain forest at the northern edge of the tropical zone. The tropical montane rain forest occurs at wet montane habitats and is similar to the lower montane rain forest in equatorial Asia in floristic composition and physiognomy. It is a type of lower montane rain forests within the broader category of tropical rain forests. The tropical seasonal moist forest occurs on middle and upper

The Influence of Forest Management Regimes on Deforestation in a Central Indian Dry Deciduous Forest Landscape

OpenAIRE

Shivani Agarwal; Harini Nagendra; Rucha Ghate

2016-01-01

This research examines the impact of forest management regimes, with various degrees of restriction, on forest conservation in a dry deciduous Indian forest landscape. Forest change is mapped using Landsat satellite images from 1977, 1990, 1999, and 2011. The landscape studied has lost 1478 km2 of dense forest cover between 1977 and 2011, with a maximum loss of 1002 km2 of dense forest between 1977 and 1990. The number of protected forest areas has increased, concomitant with an increase in r...

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

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Luciana Mestre

2017-05-01

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

The Pleistocene biogeography of eastern North America: A nonmigration scenario for deciduous forest

Energy Technology Data Exchange (ETDEWEB)

Loehle, C. [Argonne National Lab., IL (United States). Environmental Research Div.; Iltis, H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Botany

1998-12-31

The current reconstruction of the vegetation of eastern North America at the last glacial maximum postulates a very wide zone of tundra and boreal forest south of the ice. This reconstruction requires that the deciduous forest retreated far to the south. The authors believe that this reconstruction is seriously in error. Geologic evidence for glacial activity or tundra is absent from the southern Appalachians. Positive evidence for boreal forest is based on pollen identifications for Picea, Betula, and Pinus, when in reality southern members of these genera have pollen that cannot be distinguished from that of northern members. Further, pollen of typical southern species such as oaks and hickories occurs throughout profiles that past authors had labeled boreal. Pollen evidence for a far southern deciduous forest refuge is lacking. Data on endemics are particularly challenging for the scenario in which deciduous forest migrated to the south and back. The southern Appalachian region is rife with endemics that are often extreme-habitat specialists unable to migrate. The previously glaciated zone is almost completely lacking in endemics. Outlier populations, range boundaries, and absence of certain hybrids all argue against a large boreal zone. The new reconstruction postulates a cold zone no more than 75--100 miles wide south of the ice in the East.

TREE SPECIES CLASSIFICATION OF BROADLEAVED FORESTS IN NAGANO, CENTRAL JAPAN, USING AIRBORNE LASER DATA AND MULTISPECTRAL IMAGES

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S. Deng

2017-10-01

Full Text Available This study attempted to classify three coniferous and ten broadleaved tree species by combining airborne laser scanning (ALS data and multispectral images. The study area, located in Nagano, central Japan, is within the broadleaved forests of the Afan Woodland area. A total of 235 trees were surveyed in 2016, and we recorded the species, DBH, and tree height. The geographical position of each tree was collected using a Global Navigation Satellite System (GNSS device. Tree crowns were manually detected using GNSS position data, field photographs, true-color orthoimages with three bands (red-green-blue, RGB, 3D point clouds, and a canopy height model derived from ALS data. Then a total of 69 features, including 27 image-based and 42 point-based features, were extracted from the RGB images and the ALS data to classify tree species. Finally, the detected tree crowns were classified into two classes for the first level (coniferous and broadleaved trees, four classes for the second level (Pinus densiflora, Larix kaempferi, Cryptomeria japonica, and broadleaved trees, and 13 classes for the third level (three coniferous and ten broadleaved species, using the 27 image-based features, 42 point-based features, all 69 features, and the best combination of features identified using a neighborhood component analysis algorithm, respectively. The overall classification accuracies reached 90 % at the first and second levels but less than 60 % at the third level. The classifications using the best combinations of features had higher accuracies than those using the image-based and point-based features and the combination of all of the 69 features.

Forest meteorology research within the Oak Ridge site, eastern deciduous forest biome, USIBP

International Nuclear Information System (INIS)

Hutchison, B.A.; Matt, D.R.

1977-01-01

The data presented here indicate that the diurnal trends in forest microclimate are dominated by the diurnal trend in incident solar radiation amounts and the diurnal changes in solar elevations. Absolute values of these microclimatic variables, on the other hand, reflect strongly, the synoptic climatic conditions present and, to a lesser degree, the interactions among synoptic climatic parameters, forest structure, forest physiology, and soil moisture conditions. The seasonal changes in forest microclimate are the result of changes in incident radiation amounts, earth-sun geometry, and phenological change in forest structure along with seasonal changes in synoptic climatic parameters. The temporal and spatial variations of solar radiation within and above a deciduous forest composed predominately of tulip poplar (biriodendron tulipifera) were documented and on attempt was made to relate the variations to forest structure

Trends in Spring Phenology of Western European Deciduous Forests

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Eliakim Hamunyela

2013-11-01

Full Text Available Plant phenology is changing because of recent global warming, and this change may precipitate changes in animal distribution (e.g., pests, alter the synchronization between species, and have feedback effects on the climate system through the alteration of biogeochemical and physical processes of vegetated land surface. Here, ground observations (leaf unfolding/first leaf separation of six deciduous tree species and satellite-derived start-of-growing season (SOS are used to assess how the timing of leafing/SOS in Western European deciduous forest responded to climate variability between 2001 and 2011 and evaluate the reliability of satellite SOS estimates in tracking the response of forest leafing to climate variability in this area. Satellite SOS estimates are derived from the Normalized Difference Vegetation Index (NDVI time series of the Moderate Resolution Imaging Spectroradiometer (MODIS. Temporal trends in the SOS are quantified using linear regression, expressing SOS as a function of time. We demonstrated that the growing season was starting earlier between 2001 and 2011 for the majority of temperate deciduous forests in Western Europe, possibly influenced by regional spring warming effects experienced during the same period. A significant shift of up to 3 weeks to early leafing was found in both ground observations and satellite SOS estimates. We also show that the magnitude and trajectory of shifts in satellite SOS estimates are well comparable to that of in situ observations, hence highlighting the importance of satellite imagery in monitoring leaf phenology under a changing climate.

Effect of urbanization on the structure and functional traits of remnant subtropical evergreen broad-leaved forests in South China

Science.gov (United States)

Liujing Huang; Hongfeng Chen; Hai Ren; Jun Wang; Qinfeng Guo

2013-01-01

We investigated the effects of major environmental drivers associated with urbanization on species diversity and plant functional traits (PFTs) in the remnant subtropical evergreen broad-leaved forests in Metropolitan Guangzhou (Guangdong, China). Twenty environmental factors including topography, light, and soil properties were used to quantify the effects of...

Invertebrate populations of the deciduous forest: fluctuations and relations to weather

National Research Council Canada - National Science Library

Kendeigh, S. Charles

1979-01-01

The major objectives of the present study are to analyze (a) the composition and relative population sizes of the larger invertebrate fauna of relatively undisturbed, near-virgin, stands of deciduous forest, (b...

Removal of PM10 by Forests as a Nature-Based Solution for Air Quality Improvement in the Metropolitan City of Rome

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Federica Marando

2016-07-01

Full Text Available Nature-based solutions have been identified by the European Union as being critical for the enhancement of environmental qualities in cities, where urban and peri-urban forests play a key role in air quality amelioration through pollutant removal. A remote sensing and geographic information system (GIS approach was applied to the Metropolitan City (MC of Rome to assess the seasonal particulate matter (PM10 removal capacity of evergreen (broadleaves and conifers and deciduous species. Moreover, a monetary evaluation of PM10 removal was performed on the basis of pollution externalities calculated for Europe. Deciduous broadleaves represent the most abundant tree functional group and also yielded the highest total annual PM10 deposition values (1769 Mg. By contrast, PM10 removal efficiency (Mg·ha−1 was 15%–22% higher in evergreen than in deciduous species. To assess the different removal capacity of the three functional groups in an area with homogeneous environmental conditions, a study case was performed in a peri-urban forest protected natural reserve (Castelporziano Presidential Estate. This study case highlighted the importance of deciduous species in summer and of evergreen communities as regards the annual PM10 removal balance. The monetary evaluation indicated that the overall PM10 removal value of the MC of Rome amounted to 161.78 million Euros. Our study lends further support to the crucial role played by nature-based solutions for human well-being in urban areas.

Resource partitioning by evergreen and deciduous species in a tropical dry forest.

Science.gov (United States)

Álvarez-Yépiz, Juan C; Búrquez, Alberto; Martínez-Yrízar, Angelina; Teece, Mark; Yépez, Enrico A; Dovciak, Martin

2017-02-01

Niche differentiation can lead to coexistence of plant species by partitioning limiting resources. Light partitioning promotes niche differentiation in tropical humid forests, but it is unclear how niche partitioning occurs in tropical dry forests where both light and soil resources can be limiting. We studied the adult niche of four dominant evergreen (cycad, palm) and drought-deciduous (legume, oak) species co-occurring along environmental gradients. We analyzed light intensity and soil fertility effects on key functional traits related to plant carbon and water economy, how these traits determine species' functional strategies, and how these strategies relate to relative species abundance and spatial patterns. Light intensity was negatively associated with a key trait linked to plant water economy (leaf δ 13 C, a proxy for long-term water-use efficiency-WUE), while soil fertility was negatively associated with a key trait for plant carbon economy (LNC, leaf nitrogen content). Evergreens were highly sclerophyllous and displayed an efficient water economy but poor carbon economy, in agreement with a conservative resource-use strategy (i.e., high WUE but low LNC, photosynthetic rates and stature). Conversely, deciduous species, with an efficient carbon economy but poor water economy, exhibited an exploitative resource-use strategy (i.e., high LNC, photosynthetic rates and stature, but low WUE). Evergreen and deciduous species segregated spatially, particularly at fine-scales, as expected for species with different resource-use strategies. The efficient water economy of evergreens was related to their higher relative abundance, suggesting a functional advantage against drought-deciduous species in water-limited environments within seasonally dry tropical forests.

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

Science.gov (United States)

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

2004-09-01

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

HNO3 fluxes to a deciduous forest derived using gradient and REA methods

DEFF Research Database (Denmark)

Pryor, S.C.; Barthelmie, R.J.; Jensen, B.

2002-01-01

Summertime nitric acid concentrations over a deciduous forest in the midwestern United States are reported, which range between 0.36 and 3.3 mug m(-3). Fluxes to the forest are computed using the relaxed eddy accumulation technique and gradient methods. In accord with previous studies, the results...... indicate substantial uncertainties in the gradient-based calculations. The relaxed eddy accumulation (REA) derived fluxes are physically reasonable and are shown to be of similar magnitude to dry deposition estimates from gradient sampling. The REA derived mean deposition velocity is approximately 3 cm s......(-1), which is also comparable to growing season estimates derived by Meyers et al. for a similar deciduous forest. Occasional inverted concentration gradients and fluxes are observed but most are not statistically significant. Data are also presented that indicate substantial through canopy...

Investigating the role of evergreen and deciduous forests in the increasing trend in atmospheric CO2 seasonal amplitude

Science.gov (United States)

Welp, L.; Calle, L.; Graven, H. D.; Poulter, B.

2017-12-01

The seasonal amplitude of Northern Hemisphere atmospheric CO2 concentrations has systematically increased over the last several decades, indicating that the timing and amplitude of net CO2 uptake and release by northern terrestrial ecosystems has changed substantially. Remote sensing, dynamic vegetation modeling, and in-situ studies have explored how changes in phenology, expansion of woody vegetation, and changes in species composition and disturbance regimes, among others, are driven by changes in climate and CO2. Despite these efforts, ecosystem models have not been able to reproduce observed atmospheric CO2 changes. Furthermore, the implications for the source/sink balance of northern ecosystems remains unclear. Changing proportions of evergreen and deciduous tree cover in response to climate change could be one of the key mechanisms that have given rise to amplified atmospheric CO2 seasonality. These two different plant functional types (PFTs) have different carbon uptake seasonal patterns and also different sensitivities to climate change, but are often lumped together as one forest type in global ecosystem models. We will demonstrate the potential that shifting distributions of evergreen and deciduous forests can have on the amplitude of atmospheric CO2. We will show phase differences in the net CO2 seasonal uptake using CO2 flux data from paired evergreen/deciduous eddy covariance towers. We will use simulations of evergreen and deciduous PFTs from the LPJ dynamic vegetation model to explore how climate change may influence the abundance and CO2 fluxes of each. Model results show that the area of deciduous forests is predicted to have increased, and the seasonal amplitude of CO2 fluxes has increased as well. The impact of surface flux seasonal variability on atmospheric CO2 amplitude is examined by transporting fluxes from each forest PFT through the TM3 transport model. The timing of the most intense CO2 uptake leads to an enhanced effect of deciduous

Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

Science.gov (United States)

Xiaojun Du; Qinfeng Guo; Xianming Gao; Keping Na

2007-01-01

Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms.We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan,...

High rates of carbon storage in old deciduous forests: Emerging mechanisms from the Forest Accelerated Succession ExperimenT (FASET)

Science.gov (United States)

Gough, C. M.; Nave, L. E.; Hardiman, B. S.; Bohrer, G.; Halperin, A.; Maurer, K.; Le Moine, J.; Nadelhoffer, K.; Vogel, C. S.; Curtis, P.; University Of Michigan Biological Station Forest Ecosystem Study (Umbs-Fest) Team

2010-12-01

Deciduous forests of the eastern US are broadly approaching an ecological threshold in which early successional dominant trees are senescing and giving way to later successional species, with unknown consequences for regional carbon (C) cycling. Though recent research demonstrates that forests may accumulate C for centuries, the mechanisms behind sustained rates of C storage in old, particularly deciduous, forests have not been identified. In a regionally representative forest at the University of Michigan Biological Station, we are combining observational and experimental C cycling studies to forecast how forest C storage responds to climate variation, disturbance, and succession. The Forest Accelerated Succession ExperimenT (FASET), in which >6,700 aspen and birch trees (~35 % LAI) were stem girdled within a 39 ha area, is testing the hypothesis that forest production will increase rather than decline with age, due to increases in nitrogen (N) availability, N allocation to the canopy, and the concurrent development of a more biologically and structurally complex canopy. Results thus far support our hypothesis that aging forests in the region may sustain high rates of C storage through shifts in N cycling and increased canopy complexity. Girdling-induced mortality of early successional species reduced soil respiration, accelerated fine root turnover, and prompted the redistribution of N from the foliage of early to later successional species. Nitrogen redistribution increased leaf area index (LAI) production by later successional species, offsetting declines in LAI from senescing early successional species. High rates of net primary production (NPP) were sustained in stands comprising a diverse assemblage of early and later successional species because later successional species, when already present in the canopy, rapidly compensated for declining growth of early successional species. Canopy structural complexity, which increased with forest age, was positively

Accuracy of LiDAR-based tree height estimation and crown recognition in a subtropical evergreen broad-leaved forest in Okinawa, Japan

Directory of Open Access Journals (Sweden)

Azita Ahmad Zawawi

2015-04-01

Full Text Available Aim of study: To present an approach for estimating tree heights, stand density and crown patches using LiDAR data in a subtropical broad-leaved forest. Area of study: The study was conducted within the Yambaru subtropical evergreen broad-leaved forest, Okinawa main island, Japan. Materials and methods: A digital canopy height model (CHM was extracted from the LiDAR data for tree height estimation and a watershed segmentation method was applied for the individual crown delineation. Dominant tree canopy layers were estimated using multi-scale filtering and local maxima detection. The LiDAR estimation results were then compared to the ground inventory data and a high resolution orthophoto image for accuracy assessment. Main results: A Wilcoxon matched pair test suggests that LiDAR data is highly capable of estimating tree height in a subtropical forest (z = 4.0, p = 0.345, but has limitation to detect small understory trees and a single tree delineation. The results show that there is a statistically significant different type of crown detection from LiDAR data over forest inventory (z = 0, p = 0.043. We also found that LiDAR computation results underestimated the stand density and overestimated the crown size. Research highlights: Most studies involving crown detection and tree height estimation have focused on the analysis of plantations, boreal forests and temperate forests, and less was conducted on tropical and/or subtropical forests. Our study tested the capability of LiDAR as an effective application for analyzing a highly dense forest

Temporal changes in radiocesium deposition in various forest stands following the Fukushima Dai-ichi Nuclear Power Plant accident.

Science.gov (United States)

Kato, Hiroaki; Onda, Yuichi; Hisadome, Keigo; Loffredo, Nicolas; Kawamori, Ayumi

2017-01-01

In this study, we investigated the transfer of canopy-intercepted radiocesium to the forest floor following the Fukushima Dai-ichi Nuclear Power Plant accident. The 137 Cs content of throughfall, stemflow, and litterfall were monitored in two coniferous stands (plantations of Japanese cedar) and a deciduous mixed broad-leaved forest stand (oak with red pine) from July 2011 to December 2012. The forest floor of cedar stands had received higher levels of additional 137 Cs deposition compared with the mixed broad-leaved stand during the sampling period. The cumulative 137 Cs deposition during the study period was 119 kBq m -2 for the mature cedar stand, 105 kBq m -2 for the young cedar stand, and 41.5 kBq m -2 for the broad-leaved stand. The deposition of 137 Cs to the forest floor occurred mainly in throughfall during the first rainy season, from July to September 2011 (<200 d after the initial fallout); thereafter, the transfer of 137 Cs from the canopy to forest floor occurred mainly through litterfall. A double exponential field-loss model, which was used to simulate the removal of 137 Cs from canopies, was the best fit for the temporal changes in the canopy 137 Cs inventory. Copyright © 2015 Elsevier Ltd. All rights reserved.

Combined community ecology and floristics, a synthetic study on the upper montane evergreen broad-leaved forests in Yunnan, southwestern China

Institute of Scientific and Technical Information of China (English)

Hua Zhu; Yong Chai; Shisun Zhou; Lichun Yan; Jipu Shi; Guoping Yang

2016-01-01

The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous, island-like, distribution. It is diverse, rich in endemic species, and likely to be sensitive to climate change. Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan. All trees with d.b.h.>1 cm in each plot were identified. Patterns of seed plant distributions were quantified at the specific, generic and family levels. The forests are dominated by the families Fagaceae, Lauraceae, Theaceae and Magnoliaceae, but are very diverse with only a few species shared between sites. Floristic similarities at the family and generic level were high, but they were low at the specific level, with species complementarity between plots. Diversity varied greatly among sites, with greater species richness and more rare species in western Yunnan than central Yunnan. The flora is dominated by tropical biogeographical elements, mainly the pantropic and the tropical Asian distributions at the family and genus levels. In contrast, at the species level, the flora is dominated by the southwest or the southeast China distributions, including Yunnan endemics. This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin, and has adapted to cooler temperatures with the uplift of the Himalayas. Due to great sensitivity to climate, high endemism and species complementarity, as well as the discontinuous, island-like, distribution patterns of the upper montane forest in Yunnan, the regional conservation of the forest is especially needed.

Annual cycle of solar radiation in a deciduous forest

International Nuclear Information System (INIS)

Hutchison, B.A.; Matt, D.R.

1977-01-01

Periodic solar radiation measurements within and above an east Tennessee Liriodendron forest and continuous records of insolation from a nearby NOAA weather station were used to derive an approximation of the animal radiation regime within and above the deciduous forest. The interaction of changing solar elevations, insolation, and forest phenology are shown to control the radiation climate within the forest. Maximum radiation penetrates the forest in early spring as solar paths rise higher in the sky each day just prior to leaf expansion. After leaf expansion begins, average radiation received within the forest decreases rapidly despite continued increases in solar elevations and daily insolation. This forest attains full leaf in early June and from then until the advent of leaf abscission near the autumnal equinox, forest structure remains relatively static. Solar elevations and daily insolation decline following the summer solstice, however, and as a result, average radiation penetrating the forest slowly declines throughout the summer reaching an annual minimum in early autumn. With leaf fall, slightly increased amounts of radiation penetrate the forest but as within-forest solar paths continue to lengthen, radiation within the forest again declines. Minimum amounts of solar radiation penetrate the leafless forest around the winter solstice

Spatiotemporal phenological changes in fall foliage peak coloration in deciduous forest and the responses to climatic variation

Science.gov (United States)

Xie, Y.; Wilson, A. M.

2017-12-01

Plant phenology studies typically focus on the beginning and end of the growing season in temperate forests. We know too little about fall foliage peak coloration, which is a bioindicator of plant response in autumn to environmental changes, an important visual cue in fall associated with animal activities, and a key element in fall foliage ecotourism. Spatiotemporal changes in timing of fall foliage peak coloration of temperate forests and the associated environmental controls are not well understood. In this study, we examined multiple color indices to estimate Land Surface Phenology (LSP) of fall foliage peak coloration of deciduous forest in the northeastern USA using Moderate Resolution Imaging Spectroradiometer (MODIS) daily imagery from 2000 to 2015. We used long term phenology ground observations to validate our estimated LSP, and found that Visible Atmospherically Resistant Index (VARI) and Plant Senescence Reflectance Index (PSRI) were good metrics to estimate peak and end of leaf coloration period of deciduous forest. During the past 16 years, the length of period with peak fall foliage color of deciduous forest at southern New England and northern Appalachian forests regions became longer (0.3 7.7 days), mainly driven by earlier peak coloration. Northern New England, southern Appalachian forests and Ozark and Ouachita mountains areas had shorter period (‒0.2 ‒9.2 days) mainly due to earlier end of leaf coloration. Changes in peak and end of leaf coloration not only were associated with changing temperature in spring and fall, but also to drought and heat in summer, and heavy precipitation in both summer and fall. The associations between leaf peak coloration phenology and climatic variations were not consistent among ecoregions. Our findings suggested divergent change patterns in fall foliage peak coloration phenology in deciduous forests, and improved our understanding in the environmental control on timing of fall foliage color change.

Litter input controls on soil carbon in a temperate deciduous forest

DEFF Research Database (Denmark)

Bowden, Richard D.; Deem, Lauren; Plante, Alain F.

2014-01-01

Above- and belowground litter inputs in a temperate deciduous forest were altered for 20 yr to determine the importance of leaves and roots on soil C and soil organic matter (SOM) quantity and quality. Carbon and SOM quantity and quality were measured in the O horizon and mineral soil to 50 cm...... soil C, but decreases in litter inputs resulted in rapid soil C declines. Root litter may ultimately provide more stable sources of soil C. Management activities or environmental alterations that decrease litter inputs in mature forests can lower soil C content; however, increases in forest...

Chronic water stress reduces tree growth and the carbon sink of deciduous hardwood forests.

Science.gov (United States)

Brzostek, Edward R; Dragoni, Danilo; Schmid, Hans Peter; Rahman, Abdullah F; Sims, Daniel; Wayson, Craig A; Johnson, Daniel J; Phillips, Richard P

2014-08-01

Predicted decreases in water availability across the temperate forest biome have the potential to offset gains in carbon (C) uptake from phenology trends, rising atmospheric CO2 , and nitrogen deposition. While it is well established that severe droughts reduce the C sink of forests by inducing tree mortality, the impacts of mild but chronic water stress on forest phenology and physiology are largely unknown. We quantified the C consequences of chronic water stress using a 13-year record of tree growth (n = 200 trees), soil moisture, and ecosystem C balance at the Morgan-Monroe State Forest (MMSF) in Indiana, and a regional 11-year record of tree growth (n > 300 000 trees) and water availability for the 20 most dominant deciduous broadleaf tree species across the eastern and midwestern USA. We show that despite ~26 more days of C assimilation by trees at the MMSF, increasing water stress decreased the number of days of wood production by ~42 days over the same period, reducing the annual accrual of C in woody biomass by 41%. Across the deciduous forest region, water stress induced similar declines in tree growth, particularly for water-demanding 'mesophytic' tree species. Given the current replacement of water-stress adapted 'xerophytic' tree species by mesophytic tree species, we estimate that chronic water stress has the potential to decrease the C sink of deciduous forests by up to 17% (0.04 Pg C yr(-1) ) in the coming decades. This reduction in the C sink due to mesophication and chronic water stress is equivalent to an additional 1-3 days of global C emissions from fossil fuel burning each year. Collectively, our results indicate that regional declines in water availability may offset the growth-enhancing effects of other global changes and reduce the extent to which forests ameliorate climate warming. © 2014 John Wiley & Sons Ltd.

Interannual Variations in Ecosystem Oxidative Ratio in Croplands, Deciduous Forest, Coniferous Forest, and Early Successional Forest Ecosystems

Science.gov (United States)

Masiello, C. A.; Hockaday, W. C.; Gallagher, M. E.; Calligan, L.

2009-12-01

Ecosystem net primary productivity (NPP) can vary significantly with annual variations in precipitation and temperature. These climate variations can also drive changes in plant carbon allocation patterns. Shifting allocation patterns can lead to variation in net ecosystem biochemical stocks (e.g. kg cellulose, lignin, protein, and lipid/ha), which can in turn lead to shifts in ecosystem oxidative ratio (OR). OR is the molar ratio of O2 released : CO2 fixed during biosynthesis. Major plant biochemicals vary substantially in oxidative ratio, ranging from average organic acid OR values of 0.75 to average lipid OR values of 1.37 (Masiello et al., 2008). OR is a basic property of ecosystem biochemistry, and is also an essential variable needed to constrain the size of the terrestrial biospheric carbon sink (Keeling et al., 1996). OR is commonly assumed to be 1.10 (e.g. Prentice et al., 2001), but small variations in net ecosystem OR can drive large errors in estimates of the size of the terrestrial carbon sink (Randerson et al., 2006). We hypothesized that interannual changes in climate may drive interannual variation in ecosystem OR values. Working at Kellogg Biological Station NSF LTER, we measured the annual average OR of coniferous and deciduous forests, an early successional forest, and croplands under both corn and soy. There are clear distinctions between individual ecosystems (e.g., the soy crops have a higher OR than the corn crops, and the coniferous forests have a higher OR than the deciduous forests), but the ecosystems themselves retained remarkably constant annual OR values between 1998 and 2008.

Vertical and horizontal distribution of radiocesium around trees in forest soil of deciduous forests, Fukushima, Japan

Energy Technology Data Exchange (ETDEWEB)

Takada, Mono; Oba, Yurika; Nursal, Wim I.; Yamada, Toshihiro; Okuda, Toshinori [Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi- Hiroshima 739-8521 (Japan); Shizuma, Kiyoshi [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan)

2014-07-01

After the 2011 Nuclear Power Plant accident in Japan, large amount of radionuclides were deposited and remains in the forest land of Fukushima region, yet still uncertain how much deposition stays in the forest. This region is mostly covered by the secondary deciduous forest which sporadically includes Japanese fir (Abies firma). As the leaves of all deciduous trees were shed, we hypothesized that the amounts of deposition radionuclides will be exhibit difference between the conifer trees (Japanese fir) and the other deciduous trees. As these trees inhabit on steep slopes, we also hypothesized there are differences in the radionuclides deposition in soils in relation to the position around tree trunk base (upper side, lower side and mid side at the foot of trees), tree species and slope angles. Study site and method: our study was conducted in deciduous forest of Fukushima region in August 2013, two and a half years after the accident. Samples of litter layer and two soil layers (0 - 5, 5 - 10 cm) were collected under Abies firma and eight deciduous tree species. In total 23 trees in eight forest stands were investigated. Under one tree, samples were taken from four pints (upper side, lower side and mid sides at the foot of trees) around a tree trunk within a radius of one meter from the base of tree trunks. Angle of slope at each tree was also checked. The samples were dried (70 deg. C, 48 hr) and radiocesium and potassium-40 was determined by a germanium detector (GEM Series HPGe Coaxial Detector System) (measurement time 300 - 30000 sec). Results and discussion: we found that radiocesium contained in litter layer accounts for more than 80% of total amount (within litter layer to 10 cm depth from the surface), and almost all the radiocesium exists within litter layer up to 5 cm depth. Although it is well known that cesium shows similar movement to potassium in a plant body, soil contained much more amount of potassium-40 than litter layer. We predicted that

Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China

Directory of Open Access Journals (Sweden)

Yang Lu

2016-01-01

Full Text Available Subtropical evergreen broad-leaved forest (EBLF is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ≥50% for 19 species. The median length of germination time (MLG ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (≥15 cm in height within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration.

Spatial patterning of fuels and fire hazard across a central U.S. deciduous forest region

Science.gov (United States)

Michael C. Stambaugh; Daniel C. Dey; Richard P. Guyette; Hong S. He; Joseph M. Marschall

2011-01-01

Information describing spatial and temporal variability of forest fuel conditions is essential to assessing overall fire hazard and risk. Limited information exists describing spatial characteristics of fuels in the eastern deciduous forest region, particularly in dry oak-dominated regions that historically burned relatively frequently. From an extensive fuels survey...

Retrieval of forest biomass for tropical deciduous mixed forest using ALOS PALSAR mosaic imagery and field plot data

Science.gov (United States)

Ningthoujam, Ramesh K.; Joshi, P. K.; Roy, P. S.

2018-07-01

Tropical forest is an important ecosystem rich in biodiversity and structural complexity with high woody biomass content. Longer wavelength radar data at L-band sensor provides improved forest biomass (AGB) information due to its higher penetration level and sensitivity to canopy structure. The study presents a regression based woody biomass estimation for tropical deciduous mixed forest dominated by Shorea robusta using ALOS PALSAR mosaic (HH, HV) and field data at the lower Himalayan belt of Northern India. For the purpose of understanding the scattering mechanisms at L-band from this forest type, Michigan Microwave Canopy Scattering model (MIMICS-I) was parameterized with field data to simulate backscatter across polarization and incidence range. Regression analysis between field measured forest biomass and L-band backscatter data from PALSAR mosaic show retrieval of woody biomass up to 100 Mg ha-1 with error between 92 and 94 Mg ha-1 and coefficient of determination (r2) between 0.53 and 0.55 for HH and HH + HV polarized channel at 0.25 ha resolution. This positive relationship could be due to strong volume scattering from ground/trunk interaction at HH-polarized while in combination with direct canopy scattering for HV-polarization at ALOS specific incidence angles as predicted by MIMICS-I model. This study has found that L-band SAR data from currently ALOS-1/-2 and upcoming joint NASA-ISRO SAR (NISAR) are suitable for mapping forest biomass ≤100 Mg ha-1 at 25 m resolution in far incidence range in dense deciduous mixed forest of Northern India.

A compartment model of plutonium dynamics in a deciduous forest ecosystem

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Gardner, R.H.; Dahlman, R.C.

1978-01-01

A linear compartment donor-controlled model was designed to describe and simulate the behaviour of plutonium ( 239 , 240 Pu) in a contaminated deciduous forest ecosystem at Oak Ridge, Tennessee. At steady states predicted by the model, less than 0.25% of the Pu in the ecosystem resides in forest biota. Soil is the major repository of Pu in the forest, and reciprocal exchanges of Pu between soil and litter or soil and tree roots were dominant transfers affecting the ecosystem distribution of Pu. Variation in predicted steady state amounts of Pu in the forest, given variability in the model parameters, indicated that ones ability to develop reliable models of Pu transport in ecosystems will improve with greater precision in data from natural environments and a better understanding of sources of variation in Pu data. (author)

Synthesis on the carbon budget and cycling in a Danish, temperate deciduous forest

DEFF Research Database (Denmark)

Wu, Jian; Larsen, Klaus Steenberg; van der Linden, Leon

2013-01-01

A synthesis of five years (2006–2010) of data on carbon cycling in a temperate deciduous forest, Sorø (Zealand, Denmark) was performed by combining all available data from eddy covariance, chamber, suction cups, and biometric measurements. The net ecosystem exchange of CO2 (NEE), soil respiration...... within the ecosystem. The results showed that this temperate deciduous forest was a moderate carbon sink (258±41gCm−2 yr−1) with both high rates of gross primary production (GPP, 1881±95gCm−2 yr−1) and ecosystem respiration (Re, 1624±197gCm−2 yr−1). Approximately 62% of the gross assimilated carbon......, tree growth, litter production and leaching of dissolved inorganic and organic carbon were independently estimated and used to calculate other unmeasured ecosystem carbon budget (ECB) components, based on mass balance equations. This provided a complete assessment of the carbon storage and allocation...

Intersectoral assessment of impacts on seabirds. Baseline report for an integrated management plan for the North Sea and Skagerrak.; Grunnlagsrapport til en helhetlig forvaltningsplan for Nordsjoen og Skagerrak

Energy Technology Data Exchange (ETDEWEB)

Gasbjerg, Gry; Christensen-Dalsgaard, Signe; Lorentsen, Svein Haakon; Systad, Geir Helge; Anker-Nilssen, Tycho

2011-07-01

Norwegian forests are important for the forest industry, for the conservation of biodiversity as well as for carbon storage and uptake of Co2. In this project we have identified valuable forest types for biodiversity and conservation interests, and examined how data from the National Forest Inventory can be used to calculate the carbon storage and uptake of Co2 of these forest types, as well as their theoretical profitability for forestry. The selection of biologically valuable forest types are partly based on important habitats according to DN Handbook 13, forest habitats with high incidence of redlisted species, priority forest types for protection, as well as the Red List of forest types according Nature Types in Norway (NiN). Identification and occurrence of these different forest types may be partly based on underlying ecological gradients, especially for nutrients and moisture, on bioclimatic gradients, forest age, and presence of special terrain features (e.g. stream gullies). To identify similar forest types based on the National Forest Inventory data, simplified and adapted criteria were applied: vegetation type, site quality, age/development class, tree species, and climate zone, plus some special natural features such as stream gullies. With these selection criteria the sum of biologically valuable forest covers 27% of the total forest area, where unproductive older deciduous forests alone account for more than 15% of forest land and other forest types each make up 2-4%. Hence, this selection of forest types includes forest areas with limited value for biodiversity. The biologically valuable forest types have approximately the same significance for carbon stor-age and uptake of Co2 as other forests with similar productivity. The largest carbon stocks per unit area are found in old forests, especially old spruce and mature deciduous broadleaved forests, whereas unproductive mature deciduous forest has the lowest carbon stocks per unit area. Summed over

The bacterial community inhabiting temperate deciduous forests is vertically stratified and undergoes seasonal dynamics

Czech Academy of Sciences Publication Activity Database

López-Mondéjar, Rubén; Voříšková, Jana; Větrovský, Tomáš; Baldrian, Petr

2015-01-01

Roč. 87, č. 1 (2015), s. 43-50 ISSN 0038-0717 R&D Projects: GA MŠk(CZ) EE2.3.30.0003; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk LD12048; GA MŠk LD12050 Institutional support: RVO:61388971 Keywords : Bacterial community * Deciduous forest * Forest soil Subject RIV: EE - Microbiology, Virology Impact factor: 4.152, year: 2015

Interannual variability in the extent and intensity of tropical dry forest deciduousness in the Mexican Yucatan (2000-2016): Drivers and Links to Regional Atmospheric Conditions

Science.gov (United States)

Cuba, Nicholas Joseph

The dry topical forests of the southern Yucatan Peninsula experience multiple natural and anthropogenic disturbances, as well as substantial interannual climate variability that can result in stark interannual differences in vegetation phenology. Dry season deciduousness is a typical response to limit tree water loss during prolonged periods of hot and dry conditions, and this behavior has both direct implications for ecosystem functioning, and the potential to indicate climate conditions when observed using remotely-sensed data. The first research paper of this dissertation advances methods to assess the accuracy of remotely-sensed measurements of canopy conditions using in-situ observations. Linear regression models show the highest correlation (R2 = 0.751) between in-situ canopy gap fraction and Landsat NDWISWIR2. MODIS time series NDWISWIR2 are created for the period March 2000-February 2011, and exhibit stronger correlation with time series of TRMM precipitation data than do MODIS EVI time series (R2= 0.48 vs. R2 = 0.43 in deciduous forest areas). The second paper examines differences between the deciduous phenology of young forest stands and older forest stands. Land-cover maps are overlaid to determine whether forested areas are greater than or less than 22 years old in 2010, and metrics related to deciduous phenology are derived from MODIS EVI2 time series in three years, 2008 to 2011. Statistical tests that compare matched pairs of young (12-22 years) and older (>22 years) forest stand age class samples are used to detect significant differences in metrics related to the intensity and timing of deciduousness. In all three years, younger forests exhibit significantly more intense deciduousness, measured as total seasonal change of EVI2 normalized by annual maximum EVI2 (pmediating environmental factors that drive the spatial and temporal variability in the intensity of deciduousness, and point toward analyzing deciduousness to reveal information about other

Effects of Habitat Structure and Fragmentation on Diversity and Abundance of Primates in Tropical Deciduous Forests in Bolivia.

Science.gov (United States)

Pyritz, Lennart W; Büntge, Anna B S; Herzog, Sebastian K; Kessler, Michael

2010-10-01

Habitat structure and anthropogenic disturbance are known to affect primate diversity and abundance. However, researchers have focused on lowland rain forests, whereas endangered deciduous forests have been neglected. We aimed to investigate the relationships between primate diversity and abundance and habitat parameters in 10 deciduous forest fragments southeast of Santa Cruz, Bolivia. We obtained primate data via line-transect surveys and visual and acoustic observations. In addition, we assessed the vegetation structure (canopy height, understory density), size, isolation time, and surrounding forest area of the fragments. We interpreted our results in the context of the historical distribution data for primates in the area before fragmentation and interviews with local people. We detected 5 of the 8 historically observed primate species: Alouatta caraya, Aotus azarae boliviensis, Callithrix melanura, Callicebus donacophilus, and Cebus libidinosus juruanus. Total species number and detection rates decreased with understory density. Detection rates also negatively correlated with forest areas in the surroundings of a fragment, which may be due to variables not assessed, i.e., fragment shape, distance to nearest town. Observations for Alouatta and Aotus were too few to conduct further statistics. Cebus and Callicebus were present in 90% and 70% of the sites, respectively, and their density did not correlate with any of the habitat variables assessed, signaling high ecological plasticity and adaptability to anthropogenic impact in these species. Detections of Callithrix were higher in areas with low forest strata. Our study provides baseline data for future fragmentation studies in Neotropical dry deciduous forests and sets a base for specific conservation measures.

Calibration of the L-MEB model over a coniferous and a deciduous forest

DEFF Research Database (Denmark)

Grant, Jennifer P.; Saleh-Contell, Kauzar; Wigneron, Jean-Pierre

2008-01-01

In this paper, the L-band Microwave Emission of the Biosphere (L-MEB) model used in the Soil Moisture and Ocean Salinity (SMOS) Level 2 Soil Moisture algorithm is calibrated using L-band (1.4 GHz) microwave measurements over a coniferous (Pine) and a deciduous (mixed/Beech) forest. This resulted...

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

International Nuclear Information System (INIS)

Zavitkovski, J.

1977-01-01

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

Allometric biomass equations for 12 tree species in coniferous and broadleaved mixed forests, Northeastern China.

Science.gov (United States)

He, Huaijiang; Zhang, Chunyu; Zhao, Xiuhai; Fousseni, Folega; Wang, Jinsong; Dai, Haijun; Yang, Song; Zuo, Qiang

2018-01-01

Understanding forest carbon budget and dynamics for sustainable resource management and ecosystem functions requires quantification of above- and below-ground biomass at individual tree species and stand levels. In this study, a total of 122 trees (9-12 per species) were destructively sampled to determine above- and below-ground biomass of 12 tree species (Acer mandshuricum, Acer mono, Betula platyphylla, Carpinus cordata, Fraxinus mandshurica, Juglans mandshurica, Maackia amurensis, P. koraiensis, Populus ussuriensis, Quercus mongolica, Tilia amurensis and Ulmus japonica) in coniferous and broadleaved mixed forests of Northeastern China, an area of the largest natural forest in the country. Biomass allocation was examined and biomass models were developed using diameter as independent variable for individual tree species and all species combined. The results showed that the largest biomass allocation of all species combined was on stems (57.1%), followed by coarse root (21.3%), branch (18.7%), and foliage (2.9%). The log-transformed model was statistically significant for all biomass components, although predicting power was higher for species-specific models than for all species combined, general biomass models, and higher for stems, roots, above-ground biomass, and total tree biomass than for branch and foliage biomass. These findings supplement the previous studies on this forest type by additional sample trees, species and locations, and support biomass research on forest carbon budget and dynamics by management activities such as thinning and harvesting in the northeastern part of China.

Succesional change and resilience of a very dry tropical deciduous forest following shifting agriculture

NARCIS (Netherlands)

Lebrija Trejos, E.E.; Bongers, F.J.J.M.; Pérez-García, E.; Meave, J.

2008-01-01

We analyzed successional patterns in a very dry tropical deciduous forest by using 15 plots differing in age after abandonment and contrasted them to secondary successions elsewhere in the tropics. We used multivariate ordination and nonlinear models to examine changes in composition and structure

Mite species (Acari: Mesostigmata new and rare to Polish fauna, inhabiting the soil of broadleaved forests dominated by small-leaved lime (Tilia cordata Mill. in Kwidzyn Forest District (N Poland

Directory of Open Access Journals (Sweden)

FALEŃCZYK-KOZIRÓG KATARZYNA

2014-06-01

Full Text Available During a two-year study on mites of the order Mesostigmata in broadleaved forest stands dominated by small-leaved lime (Tilia cordata Mill., 117 mite species were identified. Among them, 3 had been so far rarely recorded in Poland (Haemogamasus nidi, Stylochirus rovenensis and Eugamasus crassitarsis and 2 were classified as new to the Polish fauna (Veigaia sibirica and Digamasellus perpusillus.

Monitoring Spring Recovery of Photosynthesis and Spectral Reflectance in Temperate Evergreen and Mixed Deciduous Forests

Science.gov (United States)

Wong, C. Y.; Arain, M. A.; Ensminger, I.

2015-12-01

Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which characterizes their photosynthetic activity with high activity in the growing season and downregulation during the winter season. Monitoring the timing of the transitions in evergreens is difficult since it's a largely invisible process, unlike deciduous trees that have a visible budding and senescence sequence. Spectral reflectance and the photochemical reflectance index (PRI), often used as a proxy for photosynthetic light-use efficiency, provides a promising tool to track the transition of evergreens between inactive and active photosynthetic states. To better understand the relationship between PRI and photosynthetic activity and to contrast this relationship between plant functional types, the spring recovery of an evergreen forest and mixed deciduous forest was monitored using spectral reflectance, chlorophyll fluorescence and gas exchange. All metrics indicate photosynthetic recovery during the spring season. These findings indicate that PRI can be used to observe the spring recovery of photosynthesis in evergreen conifers but may not be best suited for deciduous trees. These findings have implications for remote sensing, which provides a promising long-term monitoring system of whole ecosystems, which is important since their roles in the carbon cycle may shift in response to climate change.

Sustainable cultivation of broadleaved trees in a recycling community

International Nuclear Information System (INIS)

Christersson, L.

1996-01-01

In the future, with problems of global warming and acidification and with an increasing need to recirculate wastes of the community in an ecologically acceptable and economically sound manner, the cultivation of broadleaved species (birch, aspen, poplar, alder and willow in particular) on suitable forest land and on former agricultural land is of utmost interest if following the recycling philosophy. The wood produced could be used primarily for short fibres and for energy. Also of interest is the production of methanol, biogas and electricity, chipboard and laminates, in the context of a forest industry concerned with the further development of the raw materials. The main advantages of cultivating fast-growing, broadleaved trees on former agricultural land are that: * in Sweden it has been shown possible to produce 10-12 tonnes of dry matter of woody biomass per hectare and year by cultivating willows and hybrid poplars, * in such plantations, the energy efficiency ratio will be 1 to 15-20, meaning that for every energy unit used, 15-20 can be harvested, and * some residual products from society, such as sludges, ashes, and wastewaters can be used as fertilizers in such plantations. 16 refs

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

Hydrologic response to and recovery from differing silvicultural systems in a deciduous forest landscape with seasonal snow cover

Science.gov (United States)

Buttle, J. M.; Beall, F. D.; Webster, K. L.; Hazlett, P. W.; Creed, I. F.; Semkin, R. G.; Jeffries, D. S.

2018-02-01

Hydrological consequences of alternative harvesting strategies in deciduous forest landscapes with seasonal snow cover have received relatively little attention. Most forest harvesting experiments in landscapes with seasonal snow cover have focused on clearcutting in coniferous forests. Few have examined alternative strategies such as selection or shelterwood cutting in deciduous stands whose hydrologic responses to harvesting may differ from those of conifers. This study presents results from a 31-year examination of hydrological response to and recovery from alternative harvesting strategies in a deciduous forest landscape with seasonal snow cover in central Ontario, Canada. A quantitative means of assessing hydrologic recovery to harvesting is also developed. Clearcutting resulted in increased water year (WY) runoff. This was accompanied by increased runoff in all seasons, with greatest relative increases in Summer. Direct runoff and baseflow from treatment catchments generally increased following harvesting, although annual peak streamflow did not. Largest increases in WY runoff and seasonal runoff as well as direct runoff and baseflow generally occurred in the selection harvest catchment, likely as a result of interception of hillslope runoff by a forest access road and redirection to the stream channel. Hydrologic recovery appeared to begin towards the end of the experimental period for several streamflow metrics but was incomplete for all harvesting strategies 15 years after harvesting. Geochemical tracing indicated that harvesting enhanced the relative importance of surface and near-surface water pathways on catchment slopes for all treatments, with the clearcut catchment showing the most pronounced and prolonged response. Such insights into water partitioning between flow pathways may assist assessments of the ecological and biogeochemical consequences of forest disturbance.

Linear compartment model of plutonium dynamics in a deciduous forest ecosystem

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Gardner, R.H.; Dahlman, R.C.

1977-01-01

Systems ecology techniques have been useful in simulating the fate and dynamics of radionuclides in forest ecosystems. The applications of systems models in this context are twofold: projection of the time-dependent distribution of radioisotopes among various ecosystems components, and manipulation of the modeled system to determine the sensitivity of components to variation in transfer coefficients and, thereby, identify critical fluxes affecting system behavior. The present paper describes a systems model that projects the possible fate of plutonium in a deciduous forest ecosystem. The isotopes of interest are 239 Pu and 240 Pu which have physical half lives of 2.44 x 10 4 and 6540 years, respectively. These isotopes are indistinguishable by alpha spectrometry hence 239 Pu is used to refer to both

Species-specific effects of Asian and European earthworms on microbial communities in Mid-Atlantic deciduous forests

Science.gov (United States)

Earthworm species with different feeding, burrowing, and/or casting behaviors can lead to distinct microbial communities through complex direct and indirect processes. European earthworm invasion into temperate deciduous forests in North America has been shown to alter microbial biomass in the soil ...

Broadleaf deciduous forest counterbalanced the direct effect of climate on Holocene fire regime in hemiboreal/boreal region (NE Europe)

Science.gov (United States)

Feurdean, Angelica; Veski, Siim; Florescu, Gabriela; Vannière, Boris; Pfeiffer, Mirjam; O'Hara, Robert B.; Stivrins, Normunds; Amon, Leeli; Heinsalu, Atko; Vassiljev, Jüri; Hickler, Thomas

2017-08-01

Disturbances by fire are essential for the functioning of boreal/hemiboreal forests, but knowledge of long-term fire regime dynamics is limited. We analysed macrocharcoal morphologies and pollen of a sediment record from Lake Lielais Svētiņu (eastern Latvia), and in conjunction with fire traits analysis present the first record of Holocene variability in fire regime, fuel sources and fire types in boreal forests of the Baltic region. We found a phase of moderate to high fire activity during the cool and moist early (mean fire return interval; mFRI of ∼280 years; 11,700-7500 cal yr BP) and the late (mFRI of ∼190 years; 4500-0 cal yr BP) Holocene and low fire activity (mFRI of ∼630 years) during the Holocene Thermal Optimum (7500-4500 cal yr BP). Charcoal morphotypes and the pollen record show the predominance of frequent surface fires, occasionally transitioning to the crown during Pinus sylvestris-Betula boreal forests and less frequent surface fires during the dominance of temperate deciduous forests. In contrast to the prevailing opinion that fires in boreal forests are mostly low to moderate severity surface fires, we found evidence for common occurrence of stand-replacing crown fires in Picea abies canopy. Our results highlight that charcoal morphotypes analysis allows for distinguishing the fuel types and surface from crown fires, therefore significantly advancing our interpretation of fire regime. Future warmer temperatures and increase in the frequency of dry spells and abundant biomass accumulation can enhance the fire risk on the one hand, but will probably promote the expansion of broadleaf deciduous forests to higher latitudes, on the other hand. By highlighting the capability of broadleaf deciduous forests to act as fire-suppressing landscape elements, our results suggest that fire activity may not increase in the Baltic area under future climate change.

Deciduous trees are a large and overlooked sink for snowmelt water in the boreal forest

Science.gov (United States)

Young, Jessica; Bolton, W. Robert; Bhatt, Uma; Cristobal, Jordi; Thoman, Richard

2016-01-01

The terrestrial water cycle contains large uncertainties that impact our understanding of water budgets and climate dynamics. Water storage is a key uncertainty in the boreal water budget, with tree water storage often ignored. The goal of this study is to quantify tree water content during the snowmelt and growing season periods for Alaskan and western Canadian boreal forests. Deciduous trees reached saturation between snowmelt and leaf-out, taking up 21–25% of the available snowmelt water, while coniferous trees removed <1%. We found that deciduous trees removed 17.8–20.9 billion m3 of snowmelt water, which is equivalent to 8.7–10.2% of the Yukon River’s annual discharge. Deciduous trees transpired 2–12% (0.4–2.2 billion m3) of the absorbed snowmelt water immediately after leaf-out, increasing favorable conditions for atmospheric convection, and an additional 10–30% (2.0–5.2 billion m3) between leaf-out and mid-summer. By 2100, boreal deciduous tree area is expected to increase by 1–15%, potentially resulting in an additional 0.3–3 billion m3 of snowmelt water removed from the soil per year. This study is the first to show that deciduous tree water uptake of snowmelt water represents a large but overlooked aspect of the water balance in boreal watersheds.

Close relationship between spectral vegetation indices and Vcmax in deciduous and mixed forests

Directory of Open Access Journals (Sweden)

Yanlian Zhou

2014-04-01

Full Text Available Seasonal variations of photosynthetic capacity parameters, notably the maximum carboxylation rate, Vcmax, play an important role in accurate estimation of CO2 assimilation in gas-exchange models. Satellite-derived normalised difference vegetation index (NDVI, enhanced vegetation index (EVI and model-data fusion can provide means to predict seasonal variation in Vcmax. In this study, Vcmax was obtained from a process-based model inversion, based on an ensemble Kalman filter (EnKF, and gross primary productivity, and sensible and latent heat fluxes measured using eddy covariance technique at two deciduous broadleaf forest sites and a mixed forest site. Optimised Vcmax showed considerable seasonal and inter-annual variations in both mixed and deciduous forest ecosystems. There was noticeable seasonal hysteresis in Vcmax in relation to EVI and NDVI from 8 d composites of satellite data during the growing period. When the growing period was phenologically divided into two phases (increasing VIs and decreasing VIs phases, significant seasonal correlations were found between Vcmax and VIs, mostly showing R2>0.95. Vcmax varied exponentially with increasing VIs during the first phase (increasing VIs, but second and third-order polynomials provided the best fits of Vcmax to VIs in the second phase (decreasing VIs. The relationships between NDVI and EVI with Vcmax were different. Further efforts are needed to investigate Vcmax–VIs relationships at more ecosystem sites to the use of satellite-based VIs for estimating Vcmax.

Soil macroinvertebrate communities across a productivity gradient in deciduous forests of eastern North America

Science.gov (United States)

Evelyn S. Wenk; Mac A. Callaham; Joseph O' Brien; Paul J. Hanson

2016-01-01

Within the temperate, deciduous forests of the eastern US, diverse soil-fauna communities are structured by a combination of environmental gradients and interactions with other biota. The introduction of non-native soil taxa has altered communities and soil processes, and adds another degree of variability to these systems. We sampled soil macroinvertebrate abundance...

Gall-inducing insects of deciduous and semideciduous forests in Rio Grande do Sul State, Brazil

Directory of Open Access Journals (Sweden)

Ana Paula M. Goetz

2018-06-01

Full Text Available ABSTRACT Galls are specific changes induced by insects on plant organs mainly through increases in plant cell number and/or size. Gall diversity is easy to recognize in the field because gallers are mostly species-specific, and thus each gall morphotype can be a proxy for a galling species. Insect galls are virtually unknown in Seasonal Deciduous and Semi-Deciduous forests of southern Brazil. Here, galls and host plants were surveyed between 2015 and 2017 in four forest fragments of Rio Grande do Sul State in these two vegetation types, in secondary-growth and areas under restoration. We recorded 89 gall morphotypes, with gallers belonging to Lepidoptera and Diptera, with the latter represented mainly by Cecidomyiidae. Galls were associated to 46 plant species in 27 families. Asteraceae, Piperaceae, Fabaceae, Myrtaceae and Lauraceae were the richest families in terms of galls, whilst Piper aduncum and Mikania glomerata were superhosts. Most galls occurred in leaves and shoots. The most common shapes were fusiform, globoid and lenticular. Forty-eight gall morphotype records are new for both Rio Grande do Sul and Brazil, an expressive number considering only two seasonal forest types sampled and few sampling points, showing how important surveys still are for these little know fauna both in taxonomic and ecological terms.

Tree species traits cause divergence in soil acidification during four decades of postagricultural forest development

DEFF Research Database (Denmark)

Schrijver, An de; Frenne, Pieter de; Staelens, Jeroen

2012-01-01

-depth understanding of tree species-specific effects on soil acidification is therefore crucial, particularly in view of the predicted global increases in acidifying nitrogen (N) deposition. Here, we report soil acidification rates in a chronosequence of broadleaved deciduous forests planted on former arable land...... and unequivocally drives postagricultural forests towards more acidic conditions, but the rate of soil acidification is also determined by the tree species-specific leaf litter quality and litter decomposition rates. We propose that the intrinsic differences in leaf litter quality among tree species create...... fundamentally different nutrient cycles within the ecosystem, both directly through the chemical composition of the litter and indirectly through its effects on the size and composition of earthworm communities. Poor leaf litter quality contributes to the absence of a burrowing earthworm community, which...

The longevity of broadleaf deciduous trees in Northern Hemisphere temperate forests: insights from tree-ring series

Directory of Open Access Journals (Sweden)

Alfredo eDi Filippo

2015-05-01

Full Text Available Understanding the factors controlling the expression of longevity in trees is still an outstanding challenge for tree biologists and forest ecologists. We gathered tree-ring data and literature for broadleaf deciduous (BD temperate trees growing in closed-canopy old-growth forests in the Northern Hemisphere to explore the role of geographic patterns, climate variability, and growth rates on longevity. Our pan-continental analysis, covering 32 species from 12 genera, showed that 300-400 years can be considered a baseline threshold for maximum tree lifespan in many temperate deciduous forests. Maximum age varies greatly in relation to environmental features, even within the same species. Tree longevity is generally promoted by reduced growth rates across large genetic differences and environmental gradients. We argue that slower growth rates, and the associated smaller size, provide trees with an advantage against biotic and abiotic disturbance agents, supporting the idea that size, not age, is the main constraint to tree longevity. The oldest trees were living most of their life in subordinate canopy conditions and/or within primary forests in cool temperate environments and outside major storm tracks. Very old trees are thus characterized by slow growth and often live in forests with harsh site conditions and infrequent disturbance events that kill much of the trees. Temperature inversely controls the expression of longevity in mesophilous species (Fagus spp., but its role in Quercus spp. is more complex and warrants further research in disturbance ecology. Biological, ecological and historical drivers must be considered to understand the constraints imposed to longevity within different forest landscapes.

Elevated CO2 induces changes in the ecohydrological functions of forests - from mechanisms to models

Science.gov (United States)

Pötzelsberger, Elisabeth; Warren, Jeffrey M.; Wullschleger, Stan D.; Thornton, Peter E.; Norby, Richard J.; Hasenauer, Hubert

2010-05-01

Forests are known to considerably influence ecosystem water balance as a result of the many dynamic interactions between the plant physiology, morphology, phenology and other biophysical properties and environmental conditions. A changing climate will exert a new environmental setting for the forests and the biological feedbacks will be considerable. With the mechanistic ecosystem model Biome-BGC the dense net of cause-response relationships among carbon, nitrogen, water and energy cycles at a free-air CO2 enrichment (FACE) site in a North American deciduous broadleaved forest can be represented. At the Oak Ridge National Laboratory (ORNL) closed canopy sweetgum plantation elevated CO2 caused a decrease in stomatal conductance, and concurrent changes in daily transpiration were observed. This is in agreement with data from other FACE experiments. At the ORNL FACE site average transpiration reduction in a growing season was 10-16%, with 7-16% during mid summer, depending on the year. After parameterization of the model for this ecosystem the observed transpiration patterns could be well represented. Most importantly, the complete water budget at the site could be described and increased outflow could be observed (~15%). This yields crucial information for broader scale future water budget simulations. Changes in the water balance of deciduous forests will affect a wide range of ecosystem functions, from decomposition, over carbon and nutrient cycling to plant-plant competition and species composition.

Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US

Science.gov (United States)

Johnny L. Boggs; Steven G. McNulty; Linda H. Pardo

2007-01-01

We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999...

The Influence of DEM Quality on Mapping Accuracy of Coniferous- and Deciduous-Dominated Forest Using TerraSAR‑X Images

Directory of Open Access Journals (Sweden)

Gerald Kändler

2012-03-01

Full Text Available Climate change is a factor that largely contributes to the increase of forest areas affected by natural damages. Therefore, the development of methodologies for forest monitoring and rapid assessment of affected areas is required. Space-borne synthetic aperture radar (SAR imagery with high resolution is now available for large-scale forest mapping and forest monitoring applications. However, a correct interpretation of SAR images requires an adequate preprocessing of the data consisting of orthorectification and radiometric calibration. The resolution and quality of the digital elevation model (DEM used as reference is crucial for this purpose. Therefore, the primary aim of this study was to analyze the influence of the DEM quality used in the preprocessing of the SAR data on the mapping accuracy of forest types. In order to examine TerraSAR-X images to map forest dominated by deciduous and coniferous trees, High Resolution SpotLight images were acquired for two study sites in southern Germany. The SAR images were preprocessed with a Shuttle Radar Topography Mission (SRTM DEM (resolution approximately 90 m, an airborne laser scanning (ALS digital terrain model (DTM (5 m resolution, and an ALS digital surface model (DSM (5 m resolution. The orthorectification of the SAR images using high resolution ALS DEMs was found to be important for the reduction of errors in pixel location and to increase the classification accuracy of forest types. SAR images preprocessed with ALS DTMs resulted in the highest classification accuracies, with kappa coefficients of 0.49 and 0.41, respectively. SAR images preprocessed with ALS DTMs resulted in greater accuracy than those preprocessed with ALS DSMs in most cases. The classification accuracy of forest types using SAR images preprocessed with the SRTM DEM was fair, with kappa coefficients of 0.23 and 0.32, respectively.Analysis of the radar backscatter indicated that sample plots dominated by coniferous trees

Trace gas exchange above the floor of a deciduous forest: 1. Evaporation and CO2 efflux

Science.gov (United States)

Baldocchi, Dennis D.; Meyers, Tilden P.

1991-04-01

The eddy correlation method has great potential for directly measuring trace gas fluxes at the floor of a forest canopy, but a thorough validation study has not been yet conducted. Another appeal of the eddy correlation method is its ability to study processes that regulate and modulate gas exchange between the soil/litter complex and the atmosphere that cannot be probed with chambers. In this paper we report on eddy correlation measurements of water vapor, sensible heat, and carbon dioxide exchange that were made at the floor of a deciduous forest. The validity of the eddy correlation method to measure the emission of water vapor and CO2 from a deciduous forest floor is demonstrated by our ability to close the surface energy budget during periods that meet the requirements of the technique. Water vapor fluxes from a dry forest floor are strongly influenced by large-scale turbulent events that penetrate deep into the canopy. The frequency of these turbulent events prevents equilibrium evaporation rates from being achieved because the dynamic time constant for water vapor exchange is longer. Consequently, maximal evaporation rates are capped to rates defined by the product of the driving potential of the atmosphere and the surface conductance. On the other hand, evaporation from a wet forest floor proceeds at rates reaching or exceeding equilibrium evaporation and are highly correlated with static pressure fluctuations. CO2 efflux rates are governed by litter and soil temperature, as expected. But we also find a significant correlation between static pressure fluctuations and soil/litter CO2 exchange rates.

STRUCTURE, COMPOSITION AND USE OF TREES OF THE DECIDUOUS FOREST IN APATZINGAN, MICHOACAN

Directory of Open Access Journals (Sweden)

F. Casanova-Lugo

2014-08-01

Full Text Available The aim of this study was to determine the structure, composition and use of trees and shrubs of tropical deciduous forest in the mountains of Apatzingán, Michoacan. For this, six sampling units were established and each 7 sub-plots (squares of 10 × 10 m were delineated. A floristic inventory was conducted and diameter at breast height (DBH, total height (TH, crown diameter (CD, (BA basal area and the importance value index (IVI was determined. Further, based on local knowledge the use of each species found was determined. The results show that 97.1 % of species having a DAP ≤ 10 cm. Over 90% of the sampled trees had a DC ≤ 4 m. 84.4 % of the sampled individuals had an AT ≤ 6 m, and 85 % of species had an AB ≤ 30 cm2. The species most IVI were Cordia elaeagnoides, Randia watsoni, Apoplanesia paniculate, Caesalpinia platyloba, Capparis asperifolia and Triunfetta sp. 38% of the sampled species belong to the legume family and almost 80% of the sampled species has forage use. We conclude that local knowledge of the species of deciduous forest can help establish the basis for designing new proposals to the use and conservation of local resources and generate resilient livestock production systems. Â

Phylogenetic Structure of Tree Species across Different Life Stages from Seedlings to Canopy Trees in a Subtropical Evergreen Broad-Leaved Forest.

Science.gov (United States)

Jin, Yi; Qian, Hong; Yu, Mingjian

2015-01-01

Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from seedlings to canopy trees, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of tree species from seedlings, saplings, treelets to canopy trees; we compare the phylogenetic turnover (measured as βNRI) between canopy trees and seedlings in forest understory with that between canopy trees and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy trees, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy trees and seedlings in forest understory is lower than that between canopy trees and seedlings in forest gaps. We conclude that tree species tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as tree stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved tree species whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate.

Processes governing yearly variations in carbon sequestration at a temperate deciduous forest

Science.gov (United States)

Barr, J. G.; Fuentes, J. D.; Staebler, R.; Lee, X.

2001-12-01

Since 1995, processes governing the net ecosystem exchange (NEE) of carbon dioxide have been continuously investigated at the CFB Borden temperate mixed deciduous forest in Ontario, Canada. On a yearly basis, the rates of NEE for this forest range from 0.3 to 2.5 t C ha-1. For the 1996 to 1999 period, the forest sequestered the most carbon and had the greatest seasonal carbon dioxide flux in 1997. This seasonal flux is defined as the average daily rate of NEE over the course of the growing period and is the single most important factor governing yearly NEE. Such factors as soil temperature, timing of soil thawing, and respiratory processes exert only minor influences on the yearly variability in NEE. In this presentation, we will provide evidence to support the hypothesis that maximum Rubisco capacity per unit foliage element is one key control on the NEE variability. Additionally, changes in diffuse photosysnthetically active irradiance contribute to the variability observed in NEE. We will present results from both data analyses and outputs from a biospheric modeling system which was employed to investigate seasonal rates of NEE for the Borden forest.

Effects of seasonal variation of photosynthetic capacity on the carbon fluxes of a temperate deciduous forest

Science.gov (United States)

David Medvigy; Su-Jong Jeong; Kenneth L. Clark; Nicholas S. Skowronski; Karina V. R. Schäfer

2013-01-01

Seasonal variation in photosynthetic capacity is an important part of the overall seasonal variability of temperate deciduous forests. However, it has only recently been introduced in a few terrestrial biosphere models, and many models still do not include it. The biases that result from this omission are not well understood. In this study, we use the Ecosystem...

Three-year monitoring study of radiocesium transfer and ambient dose rate in forest environments affected by the Fukushima Dai-ichi Nuclear Power Plant accident

Science.gov (United States)

Kato, Hiroaki; Onda, Yuichi; Loffredo, Nicolas; Kawamori, Ayumi; Hisadome, Keigo

2015-04-01

We investigated the transfer of canopy-intercepted radiocesium to the forest floor during 3 years (July 2011~) following the Fukushima Dai-ichi Nuclear Power Plant accident. The cesium-137 (Cs-137) contents of throughfall, stemflow, and litterfall were monitored in two coniferous stands (plantation of Japanese cedar) and a deciduous broad-leaved forest stand (Japanese oak with red pine). We also measured an ambient dose rate at different height in the forest by using a survey meter (TCS-172B, Hitachi-Aloka Medical, LTD.) and a portable Ge gamma-ray detector (Detective-DX-100T, Ortec, Ametek, Inc.). Furthermore, effects of forest decontamination on the reduction of ambient dose rate were assessed quantitatively. Total Cs-137 deposition flux from the canopy to forest floor for the mature cedar, young cedar, and the mixed broad-leaved stands were 157 kBq/m^2, 167 kBq/m^2, and 54 kBq/m^2, respectively. These values correspond to 36%, 39% and 12% of total atmospheric input after the accident. The ambient dose rate showed an exponential decrease with time for all the forest sites, however the decreasing trend differed depending on the forest type. These data suggested that an ambient dose rate in forest environment can be variable in spatially and temporally reflecting the transfer of radiocesium from canopy to forest floor. We presented the analysis results of the relationship between radiocesium deposition flux and ambient dose rate at the forest floor. In addition to that, we reported the effects of forest decontamination (e.g., tree felling, removal of organic materials, woodchip pavement) on the reduction of ambient dose rate in the forest environment.

Large-scale carbon stock assessment of woody vegetation in tropical dry deciduous forest of Sathanur reserve forest, Eastern Ghats, India.

Science.gov (United States)

Gandhi, Durai Sanjay; Sundarapandian, Somaiah

2017-04-01

Tropical dry forests are one of the most widely distributed ecosystems in tropics, which remain neglected in research, especially in the Eastern Ghats. Therefore, the present study was aimed to quantify the carbon storage in woody vegetation (trees and lianas) on large scale (30, 1 ha plots) in the dry deciduous forest of Sathanur reserve forest of Eastern Ghats. Biomass of adult (≥10 cm DBH) trees was estimated by species-specific allometric equations using diameter and wood density of species whereas in juvenile tree population and lianas, their respective general allometric equations were used to estimate the biomass. The fractional value 0.4453 was used to convert dry biomass into carbon in woody vegetation of tropical dry forest. The mean aboveground biomass value of juvenile tree population was 1.86 Mg/ha. The aboveground biomass of adult trees ranged from 64.81 to 624.96 Mg/ha with a mean of 245.90 Mg/ha. The mean aboveground biomass value of lianas was 7.98 Mg/ha. The total biomass of woody vegetation (adult trees + juvenile population of trees + lianas) ranged from 85.02 to 723.46 Mg/ha, with a mean value of 295.04 Mg/ha. Total carbon accumulated in woody vegetation in tropical dry deciduous forest ranged from 37.86 to 322.16 Mg/ha with a mean value of 131.38 Mg/ha. Adult trees accumulated 94.81% of woody biomass carbon followed by lianas (3.99%) and juvenile population of trees (1.20%). Albizia amara has the greatest biomass and carbon stock (58.31%) among trees except for two plots (24 and 25) where Chloroxylon swietenia contributed more to biomass and carbon stock. Similarly, Albizia amara (52.4%) showed greater carbon storage in juvenile population of trees followed by Chloroxylon swietenia (21.9%). Pterolobium hexapetalum (38.86%) showed a greater accumulation of carbon in liana species followed by Combretum albidum (33.04%). Even though, all the study plots are located within 10 km radius, they show a significant spatial variation among

Ecosystem-level water-use efficiency inferred from eddy covariance data: definitions, patterns and spatial up-scaling

Science.gov (United States)

Reichstein, M.; Beer, C.; Kuglitsch, F.; Papale, D.; Soussana, J. A.; Janssens, I.; Ciais, P.; Baldocchi, D.; Buchmann, N.; Verbeeck, H.; Ceulemans, R.; Moors, E.; Köstner, B.; Schulze, D.; Knohl, A.; Law, B. E.

2007-12-01

In this presentation we discuss ways to infer and to interpret water-use efficiency at ecosystem level (WUEe) from eddy covariance flux data and possibilities for scaling these patterns to regional and continental scale. In particular we convey the following: WUEe may be computed as a ratio of integrated fluxes or as the slope of carbon versus water fluxes offering different chances for interpretation. If computed from net ecosystem exchange and evapotranspiration on has to take of counfounding effects of respiration and soil evaporation. WUEe time-series at diurnal and seasonal scale is a valuable ecosystem physiological diagnostic for example about ecosystem-level responses to drought. Most often WUEe decreases during dry periods. The mean growing season ecosystem water-use efficiency of gross carbon uptake (WUEGPP) is highest in temperate broad-leaved deciduous forests, followed by temperate mixed forests, temperate evergreen conifers, Mediterranean broad-leaved deciduous forests, Mediterranean broad-leaved evergreen forests and Mediterranean evergreen conifers and boreal, grassland and tundra ecosystems. Water-use efficiency exhibits a temporally quite conservative relation with atmospheric water vapor pressure deficit (VPD) that is modified between sites by leaf area index (LAI) and soil quality, such that WUEe increases with LAI and soil water holding capacity which is related to texture. This property and tight coupling between carbon and water cycles is used to estimate catchment-scale water-use efficiency and primary productivity by integration of space-borne earth observation and river discharge data.

Soil organic matter composition and quality across fire severity gradients in coniferous and deciduous forests of the southern boreal region

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Miesel, Jessica R.; Hockaday, William C.; Kolka, Randall K.; Townsend, Philip A.

2015-06-01

Recent patterns of prolonged regional drought in southern boreal forests of the Great Lakes region, USA, suggest that the ecological effects of disturbance by wildfire may become increasingly severe. Losses of forest soil organic matter (SOM) during fire can limit soil nutrient availability and forest regeneration. These processes are also influenced by the composition of postfire SOM. We sampled the forest floor layer (i.e., full organic horizon) and 0-10 cm mineral soil from stands dominated by coniferous (Pinus banksiana Lamb.) or deciduous (Populus tremuloides Michx.) species 1-2 months after the 2011 Pagami Creek wildfire in northern Minnesota. We used solid-state 13C NMR to characterize SOM composition across a gradient of fire severity in both forest cover types. SOM composition was affected by fire, even when no statistically significant losses of total C stocks were evident. The most pronounced differences in SOM composition between burned and unburned reference areas occurred in the forest floor for both cover types. Carbohydrate stocks in forest floor and mineral horizons decreased with severity level in both cover types, whereas pyrogenic C stocks increased with severity in the coniferous forest floor and decreased in only the highest severity level in the deciduous forest floor. Loss of carbohydrate and lignin pools contributed to a decreased SOM stability index and increased decomposition index. Our results suggest that increases in fire severity expected to occur under future climate scenarios may lead to changes in SOM composition and dynamics with consequences for postfire forest recovery and C uptake.

Tree Death Not Resulting in Gap Creation: An Investigation of Canopy Dynamics of Northern Temperate Deciduous Forests

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Jean-Francois Senécal

2018-01-01

Full Text Available Several decades of research have shown that canopy gaps drive tree renewal processes in the temperate deciduous forest biome. In the literature, canopy gaps are usually defined as canopy openings that are created by partial or total tree death of one or more canopy trees. In this study, we investigate linkages between tree damage mechanisms and the formation or not of new canopy gaps in northern temperate deciduous forests. We studied height loss processes in unmanaged and managed forests recovering from partial cutting with multi-temporal airborne Lidar data. The Lidar dataset was used to detect areas where canopy height reduction occurred, which were then field-studied to identify the tree damage mechanisms implicated. We also sampled the density of leaf material along transects to characterize canopy structure. We used the dataset of the canopy height reduction areas in a multi-model inference analysis to determine whether canopy structures or tree damage mechanisms most influenced the creation of new canopy gaps within canopy height reduction areas. According to our model, new canopy gaps are created mainly when canopy damage enlarges existing gaps or when height is reduced over areas without an already established dense sub-canopy tree layer.

Distribution patterns of the subtropical evergreen broad-leaved forests of southwestern China, as compared with those of the eastern Chinese subtropical regions

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Tang, C. Q.

2015-12-01

Full Text Available This paper analyzes the geographic distribution patterns of the subtropical evergreen broad-leaved forests of southwestern China, and compares with other subtropical regions in the east of China in terms of forest types, pertinent species, and spatial distribution along latitudinal, longitudinal and altitudinal gradients. In general, for both the western and the eastern subtropical regions, the evergreen broad-leaved forests are dominated by species of Castanopsis, Lithocarpus, Cyclobalanopsis (Fagaceae, Machilus, Cinnamomum (Lauraceae, Schima (Theaceae, Manglietia, and Michelia, (Magnoliaceae, while in southwestern China there are more diverse forest types including semi-humid, monsoon, mid-montane moist and humid evergreen broad-leaved forests, but only monsoon and humid forests in the east. The Yunnan area has more varied species of Lithocarpus or Cyclobalanopsis or Castanopsis as dominants than does eastern China, where the chief dominant genus is Castanopsis. The upper limits of the evergreen broad-leaved forests are mainly 2400–2800 m in western Yunnan and western Sichuan, much higher than in eastern China (600–1500, but 2500 m in Taiwan. Also discussed are the environmental effects on plant diversity of the evergreen broad-leaved forest ecosystems exemplified by Yunnan and Taiwan.En este trabajo se analiza los patrones de distribución geográfica de los bosques subtropicales perennifolios de hoja ancha del suroeste de china, y se comparan con los de otras regiones subtropicales del este de China en términos de tipología de bosque, especies relevantes, y distribución espacial a lo largo de un gradiente latitudinal, longitudinal y altitudinal. De manera general, los bosques perennifolios de hoja ancha de la regiones subtropicales tanto orientales como occidentales presentan dominancia de especies de Castanopsis, Lithocarpus, Cyclobalanopsis (Fagaceae, Machilus, Cinnamomum (Lauraceae, Schima (Theaceae, Manglietia y Michelia

How Biotic Differentiation of Human Impacted Nutrient Poor Deciduous Forests Can Affect the Preservation Status of Mountain Forest Vegetation

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Tomasz Durak

2016-10-01

Full Text Available A significant loss of biodiversity resulting from human activity has caused biotic homogenisation to become the dominant process shaping forest communities. In this paper, we present a rare case of biotic differentiation in European temperate deciduous forest herb layer vegetation. The process is occurring in nutrient poor oak-hornbeam forests in mountain areas (Polish Eastern Carpathians, Central Europe where non-timber use was converted into conventional forest management practice. This change contributed to increases in the nitrogen content and pH reaction of the soil that, contrary to predominant beliefs on the negative impact of habitat eutrophication on diversity, did not result in a decrease in the latter. We discuss possible reasons for this phenomenon that indicate the important role of tree stand composition (an increasing admixture of beech worsening the trophic properties of the soil. The second issue considered involves the effect of the changes in herb species composition of oak-hornbeam forest on its distinctiveness from the beech forest predominating in the Polish Eastern Carpathians. Unfortunately, despite the increase in the species compositional dissimilarity of oak-hornbeam forest, a reduction in their distinctiveness in relation to the herb species composition of beech forest was found. Such a phenomenon is an effect of the major fragmentation of oak-hornbeam forests, a spread of beech forest-type species, and forest management that gives preference to beech trees. Consequently, it can be expected that changes occurring in oak-hornbeam forest vegetation will contribute to a decrease in the forest vegetation variability at the regional scale.

How competitive is drought deciduousness in tropical forests? A combined eco-hydrological and eco-evolutionary approach

Science.gov (United States)

Vico, Giulia; Dralle, David; Feng, Xue; Thompson, Sally; Manzoni, Stefano

2017-06-01

Drought-deciduous and evergreen species are both common in tropical forests, where there is the need to cope with water shortages during periodic dry spells and over the course of the dry season. Which phenological strategy is favored depends on the long-term balance of carbon costs and gains that leaf phenology imposes as a result of the alternation of wet and dry seasons and the unpredictability of rainfall events. This study integrates a stochastic eco-hydrological framework with key plant economy traits to derive the long-term average annual net carbon gain of trees exhibiting different phenological strategies in tropical forests. The average net carbon gain is used as a measure of fitness to assess which phenological strategies are more productive and more evolutionarily stable (i.e. not prone to invasion by species with a different strategy). The evergreen strategy results in a higher net carbon gain and more evolutionarily stable communities with increasing wet season lengths. Reductions in the length of the wet season or the total rainfall, as predicted under climate change scenarios, should promote a shift towards more drought-deciduous communities, with ensuing implications for ecosystem functioning.

Organic carbon efflux from a deciduous forest catchment in Korea

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S. J. Kim

2010-04-01

Full Text Available Soil infiltration and surface discharge of precipitation are critical processes that affect the efflux of Dissolved Organic Carbon (DOC and Particulate Organic Carbon (POC in forested catchments. Concentrations of DOC and POC can be very high in the soil surface in most forest ecosystems and their efflux may not be negligible particularly under the monsoon climate. In East Asia, however, there are little data available to evaluate the role of such processes in forest carbon budget. In this paper, we address two basic questions: (1 how does stream discharge respond to storm events in a forest catchment? and (2 how much DOC and POC are exported from the catchment particularly during the summer monsoon period? To answer these questions, we collected hydrological data (e.g., precipitation, soil moisture, runoff discharge, groundwater level and conducted hydrochemical analyses (including DOC, POC, and six tracers in a deciduous forest catchment in Gwangneung National Arboretum in west-central Korea. Based on the end-member mixing analysis of the six storm events during the summer monsoon in 2005, the surface discharge was estimated as 30 to 80% of the total runoff discharge. The stream discharge responded to precipitation within 12 h during these storm events. The annual efflux of DOC and POC from the catchment was estimated as 0.04 and 0.05 t C ha⁻¹ yr⁻¹, respectively. Approximately 70% of the annual organic carbon efflux occurred during the summer monsoon period. Overall, the annual efflux of organic carbon was estimated to be about 10% of the Net Ecosystem carbon Exchange (NEE obtained by eddy covariance measurement at the same site. Considering the current trends of increasing intensity and amount of summer rainfall and the large interannual variability in NEE, ignoring the organic carbon efflux from forest catchments would result in an inaccurate estimation of the carbon sink strength of forest ecosystems in the monsoon

Using niche-based modelling to assess the impact of climate change on tree functional diversity in Europe

DEFF Research Database (Denmark)

Thuiller, Wilfried; Lavorel, Sandra; Sykes, Martin T.

2006-01-01

Rapid anthropogenic climate change is already affecting species distributions and ecosystem functioning worldwide. We applied niche-based models to analyse the impact of climate change on tree species and functional diversity in Europe. Present-day climate was used to predict the distributions...... of 122 tree species from different functional types (FT). We then explored projections of future distributions under one climate scenario for 2080, considering two alternative dispersal assumptions: no dispersal and unlimited dispersal. The species-rich broadleaved deciduous group appeared to play a key...... role in the future of different European regions. Temperate areas were projected to lose both species richness and functional diversity due to the loss of broadleaved deciduous trees. These were projected to migrate to boreal forests, thereby increasing their species richness and functional diversity...

[Effects of simulated nitrogen deposition on soil microbial biomass carbon and nitrogen in natural evergreen broad-leaved forest in the Rainy Area of West China].

Science.gov (United States)

Zhou, Shi Xing; Zou, Cheng; Xiao, Yong Xiang; Xiang, Yuan Bin; Han, Bo Han; Tang, Jian Dong; Luo, Chao; Huang, Cong de

2017-01-01

To understand the effects of increasing nitrogen deposition on soil microbial biomass carbon (MBC) and nitrogen(MBN), an in situ experiment was conducted in a natural evergreen broad-leaved forest in Ya'an City, Sichuan Province. Four levels of nitrogen deposition were set: i.e., control (CK, 0 g N·m -2 ·a -1 ), low nitrogen (L, 5 g N·m -2 ·a -1 ), medium nitrogen (M, 15 g N·m -2 ·a -1 ), and high nitrogen (H, 30 g N·m -2 ·a -1 ). The results indicated that nitrogen deposition significantly decreased MBC and MBN in the 0-10 cm soil layer, and as N de-position increased, the inhibition effect was enhanced. L and M treatments had no significant effect on MBC and MBN in the 10-20 cm soil layer, while H treatment significantly reduced. The influence of N deposition on MBC and MBN was weakened with the increase of soil depth. MBC and MBN had obvious seasonal dynamic, which were highest in autumn and lowest in summer both in the 0-10 and 10-20 cm soil layers. The fluctuation ranges of soil microbial biomass C/N were respectively 10.58-11.19 and 9.62-12.20 in the 0-10 cm and 10-20 cm soil layers, which indicated that the fungi hold advantage in the soil microbial community in this natural evergreen broad-leaved forest.

Invaders do not require high resource levels to maintain physiological advantages in a temperate deciduous forest.

Science.gov (United States)

Heberling, J Mason; Fridley, Jason D

2016-04-01

Non-native, invasive plants are commonly typified by trait strategies associated with high resource demands and plant invasions are often thought to be dependent upon site resource availability or disturbance. However, the invasion of shade-tolerant woody species into deciduous forests of the Eastern United States seems to contradict such generalization, as growth in this ecosystem is strongly constrained by light and, secondarily, nutrient stress. In a factorial manipulation of light and soil nitrogen availability, we established an experimental resource gradient in a secondary deciduous forest to test whether three common, woody, invasive species displayed increased metabolic performance and biomass production compared to six co-occurring woody native species, and whether these predicted differences depend upon resource supply. Using hierarchical Bayesian models of photosynthesis that included leaf trait effects, we found that invasive species exhibited functional strategies associated with higher rates of carbon gain. Further, invader metabolic and growth-related attributes were more responsive to increasing light availability than those of natives, but did not fall below average native responses even in low light. Surprisingly, neither group showed direct trait or growth responses to soil N additions. However, invasive species showed increased photosynthetic nitrogen use efficiencies with decreasing N availability, while that of natives remained constant. Although invader advantage over natives was amplified in higher resource conditions in this forest, our results indicate that some invasive species can maintain physiological advantages over co-occurring natives regardless of resource conditions.

Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US

International Nuclear Information System (INIS)

Boggs, Johnny L.; McNulty, Steven G.; Pardo, Linda H.

2007-01-01

We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999, we observed a significant correlation between mean growing season temperature and red spruce basal area growth. Red spruce and deciduous foliar %N correlated significantly with N deposition. Although N deposition has not changed significantly from 1987/1988 to 1999, net nitrification potential decreased significantly at Whiteface. This decrease in net potential nitrification is not consistent with the N saturation hypothesis and suggests that non-N deposition controls, such as climatic factors and immobilization of down dead wood, might have limited N cycling. - Data from the 1999 remeasurement of the red spruce forests suggest that N deposition, to some extent, is continuing to influence red spruce across the northeastern US as illustrated by a significant correlation between N deposition and red spruce foliar %N. Our data also suggest that the decrease in forest floor %N and net nitrification potential across sites from 1987 to 1999 may be due to factors other than N deposition, such as climatic factors and N immobilization in fine woody material (<5 cm diameter)

Nitrous oxide emission inventory of German forest soils

Science.gov (United States)

Schulte-Bisping, Hubert; Brumme, Rainer; Priesack, Eckart

2003-02-01

Annual fluxes of N2O trace gas emissions were assessed after stratifying German forest soils into Seasonal Emission Pattern (SEP) and Background Emission Pattern (BEP). Broad-leaved forests with soil pH(KCl) ≤ 3.3 were assigned to have SEP, broad-leaved forests with soil pH(KCl) > 3.3 and all needle-leaved forests to have BEP. BEPs were estimated by a relationship between annual N2O emissions and carbon content of the O-horizon. SEPs were primarily controlled by temperature and moisture and simulated by the model Expert-N after calibration to a 9-year record of N2O measurements. Analysis with different climate and soil properties indicated that the model reacts highly sensitive to changes in soil temperature, soil moisture, and soil texture. A geographic information system (ARC/INFO) was used for a spatial resolution of 1 km × 1 km grid where land cover, dominant soil units, and hygro climate classes were combined. The mean annual N2O emission flux from German forest soils was estimated as 0.32 kg ha-1 yr-1. Broad-leaved forests with SEP had the highest emissions (2.05 kg ha-1 yr-1) followed by mixed forests (0.38 kg ha-1 yr-1), broad-leaved forests (0.37 kg ha-1 yr-1), and needle-leaved forests with BEP (0.17 kg ha-1 yr-1). The annual N2O emission from German forest soils was calculated as 3.26 Gg N2O-N yr-1. Although needle-leaved trees cover about 57% of the entire forest area in Germany, their contribution is low (0.96 Gg N2O-N yr-1). Broad-leaved forests cover about 22% of the forest area but have 55% higher emissions (1.49 Gg N2O-N yr-1) than needle-leaved. Mixed forests cover 21% of the area and contribute 0.81 Gg N2O-N yr-1. Compared to the total N2O emissions in Germany of 170 Gg N yr-1, forest soils contribute only 1.9%. However, there are some uncertainties in this emission inventory, which are intensely discussed.

[Simulation study on the effects of climate change on aboveground biomass of plantation in southern China: Taking Moshao forest farm in Huitong Ecological Station as an example].

Science.gov (United States)

Dai, Er Fu; Zhou, Heng; Wu, Zhuo; Wang, Xiao-Fan; Xi, Wei Min; Zhu, Jian Jia

2016-10-01

Global climate warming has significant effect on territorial ecosystem, especially on forest ecosystem. The increase in temperature and radiative forcing will significantly alter the structure and function of forest ecosystem. The southern plantation is an important part of forests in China, its response to climate change is getting more and more intense. In order to explore the responses of southern plantation to climate change under future climate scenarios and to reduce the losses that might be caused by climate change, we used climatic estimated data under three new emission scenarios, representative concentration pathways (RCPs) scenarios (RCP2.6 scenario, RCP4.5 scenario, and RCP8.5 scenario). We used the spatially dynamic forest landscape model LANDIS-2, coupled with a forest ecosystem process model PnET-2, to simulate the impact of climate change on aboveground net primary production (ANPP), species' establishment probability (SEP) and aboveground biomass of Moshao forest farm in Huitong Ecological Station, which located in Hunan Province during the period of 2014-2094. The results showed that there were obvious differences in SEP and ANPP among different forest types under changing climate. The degrees of response of SEP to climate change for different forest types were shown as: under RCP2.6 and RCP4.5, artificial coniferous forest>natural broadleaved forest>artificial broadleaved forest. Under RCP8.5, natural broadleaved forest>artificial broadleaved forest>artificial coniferous forest. The degrees of response of ANPP to climate change for different forest types were shown as: under RCP2.6, artificial broadleaved forest> natural broadleaved forest>artificial coniferous forest. Under RCP4.5 and RCP8.5, natural broadleaved forest>artificial broadleaved forest>artificial coniferous forest. The aboveground biomass of the artificial coniferous forest would decline at about 2050, but the natural broadleaved forest and artificial broadleaved forest showed a

Factors for Microbial Carbon Sources in Organic and Mineral Soils from Eastern United States Deciduous Forests

Energy Technology Data Exchange (ETDEWEB)

Stitt, Caroline R. [Mills College, Oakland, CA (United States)

2013-09-16

Forest soils represent a large portion of global terrestrial carbon; however, which soil carbon sources are used by soil microbes and respired as carbon dioxide (CO2) is not well known. This study will focus on characterizing microbial carbon sources from organic and mineral soils from four eastern United States deciduous forests using a unique radiocarbon (14C) tracer. Results from the dark incubation of organic and mineral soils are heavily influenced by site characteristics when incubated at optimal microbial activity temperature. Sites with considerable differences in temperature, texture, and location differ in carbon source attribution, indicating that site characteristics play a role in soil respiration.

Effects of Warming on Tree Species’ Recruitment in Deciduous Forests of the Eastern United States

Energy Technology Data Exchange (ETDEWEB)

Melillo, Jerry M. [Marine Biological Lab., Woods Hole, MA (United States); Clark, James S. [Duke Univ., Durham, NC (United States); Mohan, Jacqueline [Univ. of Georgia, Athens, GA (United States)

2015-03-25

Climate change is restructuring forests of the United States, although the details of this restructuring are currently uncertain. Rising temperatures of 2 to 8oC and associated changes in soil moisture will shift the competitive balance between species that compete for light and water, and so change their abilities to produce seed, germinate, grow, and survive. We have used large-scale experiments to determine the effects of warming on the most sensitive stage of species distributions, i.e., recruitment, in mixed deciduous forests in southern New England and in the Piedmont region of North Carolina. Two questions organized our research: (1) Might temperate tree species near the “warm” end of their range in the eastern United States decline in abundance during the coming century due to projected warming? and (2) Might trees near the “cool” end of their range in the eastern United States increase in abundance, or extend their range, during the coming 100 years because of projected warming? To explore these questions, we exposed seedlings to air and soil warming experiments in two eastern deciduous forest sites; one at the Harvard Forest (HF) in central Massachusetts, and the other at the Duke Forest (DF) in the Piedmont region of North Carolina. We focused on tree species common to both Harvard and Duke Forests (such as red, black, and white oaks), those near northern range limits (black oak, flowing dogwood, tulip poplar), and those near southern range limits (yellow birch, sugar maple, Virginia pine). At each site, we planted seeds and seedlings in common gardens established in temperature-controlled, open-top chambers. The experimental design was replicated and fully factorial and involved three temperature regimes (ambient, +3oC and +5oC) and two light regimes (closed forest canopy (low light) and gap conditions (high light)). Measured variables included Winter/Spring responses to temperature and mid-Summer responses to low soil moisture. This research

Effect of typhoon disturbance on soil respiration dynamic in a tropical broadleaves plantation in southern Taiwan

Science.gov (United States)

Chiang, Po-Neng; Yu, Jui-Chu; Lai, Yen-Jen

2017-04-01

Global forests contain 69% of total carbon stored in forest soil and litter. But the carbon storage ability and release rate of warming gases of forest soil also affect global climate change. Reforestation is one of the best solutions to mitigate warming gases release and to store in soil. Typhoon is one of the most hazards to disturb forest ecosystem and change carbon cycle. Typhoon disturbance is also affect soil carbon cycle such as soil respiration, carbon storage. Therefore, the objective of this study is to clarify the effect of typhoon disturbance on soil respiration dynamic in a tropical broadleaves plantation in southern Taiwan. Fourteen broadleaved tree species were planted in 2002-2005. Twelves continuous soil respiration chambers was divided two treatments (trench and non-trench) and observed since 2011 to 2014. The soil belongs to Entisol with over 60% of sandstone. The soil pH is 5.5 with low base cations because of high sand percentage. Forest biometric such as tree high, DBH, litterfall was measured in 2011-2014. Data showed that the accumulation amount of litterfall was highest in December to February and lowest in June. Soil respiration was related with season variation in research site. Soil temperature showed significantly exponential related with soil respiration in research site (p<0.001).However, soil respiration showed significantly negative relationship with total amount of litterfall (p<0.001), suggesting that the tree was still young and did not reach crown closure.

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

Directory of Open Access Journals (Sweden)

ZhiQiang Fang

2014-04-01

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

Patterns of diversity and regeneration in unmanaged moist deciduous forests in response to disturbance in Shiwalik Himalayas, India

Directory of Open Access Journals (Sweden)

Mukesh Kumar Gautam

2016-06-01

Full Text Available We studied vegetation attributes in Indian tropical moist deciduous unmanaged forests to determine the influence of forest disturbances on them. We enumerated 89 species: 72 under moderate disturbance and 54 under least disturbance. The data from 3399 stems [>5 cm diameter at breast height (dbh] decreased linearly along the disturbance gradient. The basal area was largest in least disturbed forests (61 m2/ha and smallest in intensely disturbed forest (41 m2/ha. Under least and moderate disturbance, tree density-diameter distribution had negative exponential curves, whereas highly disturbed forests had unimodal-shaped curves where a few trees 5–10 cm and >50 cm in diameter were recorded. Most tree and shrub layer species under heavy and intense disturbance had impaired regeneration. Moderate disturbance intensity thus apparently benefits species diversity, stand density, and regeneration. Decline in seedlings and saplings, especially tree species, threaten forest regeneration and the maintenance of species diversity of unmanaged tropical forests.

The influence of tree species composition on the storage and mobility of semivolatile organic compounds in forest soils

Energy Technology Data Exchange (ETDEWEB)

Komprdová, Klára, E-mail: komprdova@recetox.muni.cz [RECETOX (Research Centre for Toxic Compounds in the Environment), Kamenice 753/5, CZ-625 00 Brno (Czech Republic); Komprda, Jiří [RECETOX (Research Centre for Toxic Compounds in the Environment), Kamenice 753/5, CZ-625 00 Brno (Czech Republic); Menšík, Ladislav [Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 3, Brno 613 00 (Czech Republic); Vaňková, Lenka [RECETOX (Research Centre for Toxic Compounds in the Environment), Kamenice 753/5, CZ-625 00 Brno (Czech Republic); Kulhavý, Jiří [Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 3, Brno 613 00 (Czech Republic); Nizzetto, Luca [RECETOX (Research Centre for Toxic Compounds in the Environment), Kamenice 753/5, CZ-625 00 Brno (Czech Republic); Norwegian Institute for Water Research, Gaustadalleen 21, NO-0349 Oslo (Norway)

2016-05-15

Soil contamination with PCBs and PAHs in adjacent forest plots, characterized by a distinct composition in tree species (spruce only, mixed and beech only), was analyzed to investigate the influence of ecosystem type on contaminant mobility in soil under very similar climate and exposure conditions. Physical-chemical properties and contaminant concentrations in litter (L), organic (F, H) and mineral (A, B) soil horizons were analyzed. Contaminant distribution in the soil core varied both in relation to forest type and contaminant group/properties. Contaminant mobility in soil was assessed by examining the ratios of total organic carbon (TOC)-standardized concentrations across soil horizons (Enrichment factors, EF{sub TOC}) and the relationship between EF{sub TOC} and the octanol-water equilibrium partitioning coefficient (K{sub OW}). Contaminant distribution appeared to be highly unsteady, with pedogenic/biogeochemical drivers controlling contaminant mobility in organic layers and leaching controlling accumulation in mineral layers. Lighter PCBs displayed higher mobility in all forest types primarily controlled by leaching and, to a minor extent, diffusion. Pedogenic processes controlling the formation of soil horizons were found to be crucial drivers of PAHs and heavier PCBs distribution. All contaminants appeared to be more mobile in the soil of the broadleaved plot, followed by mixed canopy and spruce forest. Increasing proportion of deciduous broadleaf species in the forest can thus lead to faster degradation or the faster leaching of PAHs and PCBs. The composition of humic substances was found to be a better descriptor of contaminant concentration than TOC. - Highlights: • Tree species composition influences vertical distribution of PCBs and PAHs in soils. • PCBs and PAHs were more mobile in the soil of the broadleaved plot. • Low molecular weight PCBs displayed higher mobility in all forest types. • Humic substances were important descriptors of

The influence of tree species composition on the storage and mobility of semivolatile organic compounds in forest soils

International Nuclear Information System (INIS)

Komprdová, Klára; Komprda, Jiří; Menšík, Ladislav; Vaňková, Lenka; Kulhavý, Jiří; Nizzetto, Luca

2016-01-01

Soil contamination with PCBs and PAHs in adjacent forest plots, characterized by a distinct composition in tree species (spruce only, mixed and beech only), was analyzed to investigate the influence of ecosystem type on contaminant mobility in soil under very similar climate and exposure conditions. Physical-chemical properties and contaminant concentrations in litter (L), organic (F, H) and mineral (A, B) soil horizons were analyzed. Contaminant distribution in the soil core varied both in relation to forest type and contaminant group/properties. Contaminant mobility in soil was assessed by examining the ratios of total organic carbon (TOC)-standardized concentrations across soil horizons (Enrichment factors, EF_T_O_C) and the relationship between EF_T_O_C and the octanol-water equilibrium partitioning coefficient (K_O_W). Contaminant distribution appeared to be highly unsteady, with pedogenic/biogeochemical drivers controlling contaminant mobility in organic layers and leaching controlling accumulation in mineral layers. Lighter PCBs displayed higher mobility in all forest types primarily controlled by leaching and, to a minor extent, diffusion. Pedogenic processes controlling the formation of soil horizons were found to be crucial drivers of PAHs and heavier PCBs distribution. All contaminants appeared to be more mobile in the soil of the broadleaved plot, followed by mixed canopy and spruce forest. Increasing proportion of deciduous broadleaf species in the forest can thus lead to faster degradation or the faster leaching of PAHs and PCBs. The composition of humic substances was found to be a better descriptor of contaminant concentration than TOC. - Highlights: • Tree species composition influences vertical distribution of PCBs and PAHs in soils. • PCBs and PAHs were more mobile in the soil of the broadleaved plot. • Low molecular weight PCBs displayed higher mobility in all forest types. • Humic substances were important descriptors of contaminant

Biomass equations and biomass expansion factors (BEFs) for pine (pinus spp.), spruce (picea spp.) and broadleaved dominated stands in Norway

OpenAIRE

Viken, Knut Ole

2012-01-01

Abstract The objectives of this study were (1) to develop models for estimation of stand-level tree biomass for spruce (picea spp.)- pine (pinus spp.)- and broadleaved-dominated forest in Norway and, (2) develop biomass expansion factors (BEFs; ratio of stem volume to biomass) which convert stem volume to whole tree biomass for Norwegian forest conditions. A dataset from a 5 year period (2006 – 2010) from the Norwegian National Forest Inventory (NFI) were used to develop the...

Determining past leaf-out times of New England's deciduous forests from herbarium specimens.

Science.gov (United States)

Everill, Peter H; Primack, Richard B; Ellwood, Elizabeth R; Melaas, Eli K

2014-08-01

• There is great interest in studying leaf-out times of temperate forests because of the importance of leaf-out in controlling ecosystem processes, especially in the face of a changing climate. Remote sensing and modeling, combined with weather records and field observations, are increasing our knowledge of factors affecting variation in leaf-out times. Herbarium specimens represent a potential new source of information to determine whether the variation in leaf-out times observed in recent decades is comparable to longer time frames over past centuries.• Here we introduce the use of herbarium specimens as a method for studying long-term changes in leaf-out times of deciduous trees. We collected historical leaf-out data for the years 1834-2008 from common deciduous trees in New England using 1599 dated herbarium specimens with young leaves.• We found that leaf-out dates are strongly affected by spring temperature, with trees leafing out 2.70 d earlier for each degree C increase in mean April temperature. For each degree C increase in local temperature, trees leafed out 2.06 d earlier. Additionally, the mean response of leaf-out dates across all species and sites over time was 0.4 d earlier per decade. Our results are of comparable magnitude to results from studies using remote sensing and direct field observations.• Across New England, mean leaf-out dates varied geographically in close correspondence with those observed in studies using satellite data. This study demonstrates that herbarium specimens can be a valuable source of data on past leaf-out times of deciduous trees. © 2014 Botanical Society of America, Inc.

Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan

Energy Technology Data Exchange (ETDEWEB)

Zellmer, S.D. (Argonne National Lab., IL (United States)); Rastorfer, J.R. (Chicago State Univ., IL (United States). Dept. of Biological Sciences ANL/CSU Cooperative Herbarium, Chicago, IL (United States)); Van Dyke, G.D. (Trinity Christian Coll., Palos Heights, IL (United States). Dept. of Biology)

1991-07-01

Implementation of recent federal and state regulations promulgated to protect wetlands makes information on effects of gas pipeline rights-of-way (ROWs) in wetlands essential to the gas pipeline industry. This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth forested wetland sites mapped as Lenawee soils, one mature and one subjected to recent selective logging, were selected in Midland County, Michigan. Changes in the adjacent forest and successional development on the ROW are being documented. Cover-class estimates are being made for understory and ROW plant species using 1 {times}1-m quadrats. Counts are also being made for all woody species with stems < 2 cm in diameter at breast height (dbh) in the same plots used for cover-class estimates. Individual stem diameters and species counts are being recorded for all woody understory and overstory plants with stems {ge}2 cm dbh in 10 {times} 10-m plots. Although analyses of the data have not been completed, preliminary analyses indicate that some destruction of vegetation at the ROW forest edge may have been avoidable during pipeline construction. Rapid regrowth of many native wetland plant species on the ROW occurred because remnants of native vegetation and soil-bearing propagules of existing species survived on the ROW after pipeline construction and seeding operations. 91 refs., 11 figs., 3 tabs.

Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan

International Nuclear Information System (INIS)

Zellmer, S.D.; Rastorfer, J.R.; Van Dyke, G.D.

1991-07-01

Implementation of recent federal and state regulations promulgated to protect wetlands makes information on effects of gas pipeline rights-of-way (ROWs) in wetlands essential to the gas pipeline industry. This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth forested wetland sites mapped as Lenawee soils, one mature and one subjected to recent selective logging, were selected in Midland County, Michigan. Changes in the adjacent forest and successional development on the ROW are being documented. Cover-class estimates are being made for understory and ROW plant species using 1 x1-m quadrats. Counts are also being made for all woody species with stems < 2 cm in diameter at breast height (dbh) in the same plots used for cover-class estimates. Individual stem diameters and species counts are being recorded for all woody understory and overstory plants with stems ≥2 cm dbh in 10 x 10-m plots. Although analyses of the data have not been completed, preliminary analyses indicate that some destruction of vegetation at the ROW forest edge may have been avoidable during pipeline construction. Rapid regrowth of many native wetland plant species on the ROW occurred because remnants of native vegetation and soil-bearing propagules of existing species survived on the ROW after pipeline construction and seeding operations. 91 refs., 11 figs., 3 tabs

Impacts of experimentally applied mountain biking and hiking on vegetation and soil of a deciduous forest.

Science.gov (United States)

Thurston, E; Reader, R J

2001-03-01

Many recent trail degradation problems have been attributed to mountain biking because of its alleged capacity to do more damage than other activities, particularly hiking. This study compared the effects of experimentally applied mountain biking and hiking on the understory vegetation and soil of a deciduous forest. Five different intensities of biking and hiking (i.e., 0, 25, 75, 200 and 500 passes) were applied to 4-m-long x 1-m-wide lanes in Boyne Valley Provincial Park, Ontario, Canada. Measurements of plant stem density, species richness, and soil exposure were made before treatment, two weeks after treatment, and again one year after treatment. Biking and hiking generally had similar effects on vegetation and soil. Two weeks after treatment, stem density and species richness were reduced by up to 100% of pretreatment values. In addition, the amount of soil exposed increased by up to 54%. One year later, these treatment effects were no longer detectable. These results indicate that at a similar intensity of activity, the short-term impacts of mountain biking and hiking may not differ greatly in the undisturbed area of a deciduous forest habitat. The immediate impacts of both activities can be severe but rapid recovery should be expected when the activities are not allowed to continue. Implications of these results for trail recreation are discussed.

EFFECTS OF LAND-USE CHANGE ON THE PROPERTIES OF TOP SOIL OF DECIDUOUS SAL FOREST IN BANGLADESH

Directory of Open Access Journals (Sweden)

M. A. Kashem

2016-08-01

Full Text Available This study examined the effects of land use change on the physico-chemical properties of top soil in the deciduous Sal forest of Bangladesh. Relatively less disturbed Sal (Shorea robusta Roxb. Ex Gaertn. forest stands and the nearby stands those were converted into Acacia (Acacia auriculiformis Benth. plantation and pineapple (Ananus comosus (L. Merr. cultivation were selected to examine the effects of land use change on soil properties. For each land use type, soil samples were collected from 4 locations, 50m distant from each other, as replicates. Soil samples were collected at 0-5, 5-10, and 10-15 cm depths. Soil moisture content, conductivity, pH organic C, total N and total P were determined as soil properties. Leaf litter of Sal, Acacia and pineapple was incubation for 90 and 180 days in independent identical soil in order to examine the effects of plant species through leaf litter on the soil chemical nutrient (N and P status. Data showed that soil moisture content, conductivity and pH were significantly affected by land use but not by depth. However, soil organic C was affected by both land-use type (P< 0.02 and soil depth (P< 0.003, although no significant interactions appeared between these two factors. Soil total N and P did not differ between land use types but by depth and, N and P contents decreased with the increase of depth. Rates of nutrients (N and P released from Sal, Acacia and pineapple did not differ significantly among them during incubation. Results of the present study reveal that properties of the top soil of the Madhupur Sal forest are different in their responses to the varying land uses. The findings of this study are thus relevant for the sustainable management of the deciduous Sal forest ecosystems.

[Soil organic carbon pools and their turnover under two different types of forest in Xiao-xing'an Mountains, Northeast China].

Science.gov (United States)

Gao, Fei; Jiang, Hang; Cui, Xiao-yang

2015-07-01

Soil samples collected from virgin Korean pine forest and broad-leaved secondary forest in Xiaoxing'an Mountains, Northeast China were incubated in laboratory at different temperatures (8, 18 and 28 °C) for 160 days, and the data from the incubation experiment were fitted to a three-compartment, first-order kinetic model which separated soil organic carbon (SOC) into active, slow, and resistant carbon pools. Results showed that the soil organic carbon mineralization rates and the cumulative amount of C mineralized (all based on per unit of dry soil mass) of the broad-leaved secondary forest were both higher than that of the virgin Korean pine forest, whereas the mineralized C accounted for a relatively smaller part of SOC in the broad-leaved secondary forest soil. Soil active and slow carbon pools decreased with soil depth, while their proportions in SOC increased. Soil resistant carbon pool and its contribution to SOC were both greater in the broad-leaved secondary forest soil than in the virgin Korean pine forest soil, suggesting that the broad-leaved secondary forest soil organic carbon was relatively more stable. The mean retention time (MRT) of soil active carbon pool ranged from 9 to 24 d, decreasing with soil depth; while the MRT of slow carbon pool varied between 7 and 24 a, increasing with soil depth. Soil active carbon pool and its proportion in SOC increased linearly with incubation temperature, and consequently, decreased the slow carbon pool. Virgin Korean pine forest soils exhibited a higher increasing rate of active carbon pool along temperature gradient than the broad-leaved secondary forest soils, indicating that the organic carbon pool of virgin Korean pine forest soil was relatively more sensitive to temperature change.

Branch Wood Decomposition of Tree Species in a Deciduous Temperate Forest in Korea

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Sangsub Cha

2017-05-01

Full Text Available Woody debris, which is supplied by branch litter, is an important component of forest ecosystems as it contains large quantities of organic matter and nutrients. We evaluated changes in branch wood dry weight and nutrient content of six common species (Fraxinus rhynchophylla, Pinus densiflora, Prunus sargentii, Quercus mongolica, Acer pseudosieboldianum, and Symplocos chinensis for. pilosa in a deciduous temperate forest in Korea for 40 months. Branch wood disk samples 1.4–1.6 cm thick were cut, and mass loss was measured over time using the litterbag method. No significant differences in mass loss were recorded among the six tree species. Further, mass loss was negatively correlated with initial lignin concentration and positively correlated with both initial cellulose concentration and wood density for each species. Species with high wood cellulose content had high wood density while the lignin content in wood was relatively low. Accordingly, cellulose contributed to wood density, creating a relatively lower lignin content, and the decreased lignin concentration increased the wood decomposition rate.

Specific and generic stem biomass and volume models of tree species in a West African tropical semi-deciduous forest

DEFF Research Database (Denmark)

Goussanou, Cédric A.; Guendehou, Sabin; Assogbadjo, Achille E.

2016-01-01

The quantification of the contribution of tropical forests to global carbon stocks and climate change mitigation requires availability of data and tools such as allometric equations. This study made available volume and biomass models for eighteen tree species in a semi-deciduous tropical forest...... in West Africa. Generic models were also developed for the forest ecosystem, and basic wood density determined for the tree species. Non-destructive sampling approach was carried out on five hundred and one sample trees to analyse stem volume and biomass. From the modelling of volume and biomass...... enabled to conclude that the non-destructive sampling was a good approach to determining reliable basic wood density. The comparative analysis of species-specific models in this study with selected generic models for tropical forests indicated low probability to identify effective generic models with good...

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

Science.gov (United States)

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

2007-01-01

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

Scaling wood volume estimates from inventory plots to landscapes with airborne LiDAR in temperate deciduous forest

Directory of Open Access Journals (Sweden)

Shaun R. Levick

2016-05-01

Full Text Available Abstract Background Monitoring and managing carbon stocks in forested ecosystems requires accurate and repeatable quantification of the spatial distribution of wood volume at landscape to regional scales. Grid-based forest inventory networks have provided valuable records of forest structure and dynamics at individual plot scales, but in isolation they may not represent the carbon dynamics of heterogeneous landscapes encompassing diverse land-management strategies and site conditions. Airborne LiDAR has greatly enhanced forest structural characterisation and, in conjunction with field-based inventories, it provides avenues for monitoring carbon over broader spatial scales. Here we aim to enhance the integration of airborne LiDAR surveying with field-based inventories by exploring the effect of inventory plot size and number on the relationship between field-estimated and LiDAR-predicted wood volume in deciduous broad-leafed forest in central Germany. Results Estimation of wood volume from airborne LiDAR was most robust (R2 = 0.92, RMSE = 50.57 m3 ha−1 ~14.13 Mg C ha−1 when trained and tested with 1 ha experimental plot data (n = 50. Predictions based on a more extensive (n = 1100 plot network with considerably smaller (0.05 ha plots were inferior (R2 = 0.68, RMSE = 101.01 ~28.09 Mg C ha−1. Differences between the 1 and 0.05 ha volume models from LiDAR were negligible however at the scale of individual land-management units. Sample size permutation tests showed that increasing the number of inventory plots above 350 for the 0.05 ha plots returned no improvement in R2 and RMSE variability of the LiDAR-predicted wood volume model. Conclusions Our results from this study confirm the utility of LiDAR for estimating wood volume in deciduous broad-leafed forest, but highlight the challenges associated with field plot size and number in establishing robust relationships between airborne LiDAR and field derived wood volume. We

Scaling wood volume estimates from inventory plots to landscapes with airborne LiDAR in temperate deciduous forest.

Science.gov (United States)

Levick, Shaun R; Hessenmöller, Dominik; Schulze, E-Detlef

2016-12-01

Monitoring and managing carbon stocks in forested ecosystems requires accurate and repeatable quantification of the spatial distribution of wood volume at landscape to regional scales. Grid-based forest inventory networks have provided valuable records of forest structure and dynamics at individual plot scales, but in isolation they may not represent the carbon dynamics of heterogeneous landscapes encompassing diverse land-management strategies and site conditions. Airborne LiDAR has greatly enhanced forest structural characterisation and, in conjunction with field-based inventories, it provides avenues for monitoring carbon over broader spatial scales. Here we aim to enhance the integration of airborne LiDAR surveying with field-based inventories by exploring the effect of inventory plot size and number on the relationship between field-estimated and LiDAR-predicted wood volume in deciduous broad-leafed forest in central Germany. Estimation of wood volume from airborne LiDAR was most robust (R 2  = 0.92, RMSE = 50.57 m 3 ha -1  ~14.13 Mg C ha -1 ) when trained and tested with 1 ha experimental plot data (n = 50). Predictions based on a more extensive (n = 1100) plot network with considerably smaller (0.05 ha) plots were inferior (R 2  = 0.68, RMSE = 101.01 ~28.09 Mg C ha -1 ). Differences between the 1 and 0.05 ha volume models from LiDAR were negligible however at the scale of individual land-management units. Sample size permutation tests showed that increasing the number of inventory plots above 350 for the 0.05 ha plots returned no improvement in R 2 and RMSE variability of the LiDAR-predicted wood volume model. Our results from this study confirm the utility of LiDAR for estimating wood volume in deciduous broad-leafed forest, but highlight the challenges associated with field plot size and number in establishing robust relationships between airborne LiDAR and field derived wood volume. We are moving into a forest management era where

The species richness-productivity relationship in the herb layer of European deciduous forests

Czech Academy of Sciences Publication Activity Database

Axmanová, I.; Chytrý, M.; Zelený, D.; Ching-Feng, L.; Vymazalová, M.; Danihelka, Jiří; Horsák, M.; Kočí, M.; Kubešová, S.; Lososová, Z.; Otýpková, Z.; Tichý, L.; Martynenko, V. B.; Baisheva, E. Z.; Schuster, B.; Diekmann, M.

2012-01-01

Roč. 21, č. 6 (2012), s. 657-667 ISSN 1466-822X Institutional support: RVO:67985939 Keywords : broad-leaved woodland * diversity - productivity relationship * herb-layer biomass Subject RIV: EF - Botanics Impact factor: 7.223, year: 2012

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.

Phytosociology analysis of a fragment of Seasonal Deciduous Forest: Parque Estadual do Turvo, RS, Brazil

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Rafaelo Balbinot

2016-06-01

Full Text Available The ecosystem formed by the Seasonal Deciduous Forest (SDF predominates in the region of Alto Uruguay in Rio Grande do Sul State, Brazil. This study aimed to analyze descriptively the floristic composition and the phytosociology of trees from a fragment of SDF present in Parque Estadual do Turvo (PET located in the Municipality of Derrubadas, Rio Grande do Sul State (Yucumã forest. We used the method of fixed area, based on 18 sample units with 1,000 m2 installed randomly oriented by the main road of the park. All wood species with diameter at 1.3 m above ground level (DBH greater than 10 cm were measured and identified. It was observed the presence of 842 individuals belonging to 32 families, 67 genera and 83 species (12% were not identified. The families with the highest number of species were Fabaceae, Euphorbiaceae, Meliaceae, Myrtaceae and Sapindaceae. Shannon index estimated was 3.72.

Comparison of vegetation patterns and soil nutrient relations in an oak-pine forest and a mixed deciduous forest on Long Island, New York

Energy Technology Data Exchange (ETDEWEB)

Peterson, S.C.; Curtis, P.S.

1980-11-01

An analysis of soil nutrient relations in two forest communities on Long Island, NY, yielded a correlation between the fertility of the top-soil and vegetational composition. The oak-pine forest soils at Brookhaven National Laboratory contain lower average concentrations of NH/sub 3/, Ca, K, and organic matter than the mixed deciduous forest soils in the Stony Brook area. The pH of the topsoil is also more acidic at Brookhaven. The observed differences between localities are greater than within-locality differences between the two soil series tested (Plymouth and Riverhead), which are common to both localities. Nutrient concentrations in the subsoil are not consistently correlated with either locality or soil series, although organic matter and NH/sub 3/ show significantly higher concentrations at Stony Brook. Supporting data on density and basal area of trees and coverage of shrubs and herbs also reveals significant variation between the two forest communities. An ordination of the vegetation data shows higher similarity within than between localities, while no obvious pattern of within-locality variation due to soil series treatments is apparent. These data support the hypothesis that fertility gradients may influence forest community composition and structure. This hypothesis is discussed with reference to vegetation-soil interactions and other factors, such as frequency of burning, which may direct the future development of the Brookhaven oak-pine forest.

Effects of litter manipulation on litter decomposition in a successional gradients of tropical forests in southern China

DEFF Research Database (Denmark)

Chen, Hao; Gurmesa, Geshere A.; Liu, Lei

2014-01-01

Global changes such as increasing CO2, rising temperature, and land-use change are likely to drive shifts in litter inputs to forest floors, but the effects of such changes on litter decomposition remain largely unknown. We initiated a litter manipulation experiment to test the response of litter...... decomposition to litter removal/addition in three successional forests in southern China, namely masson pine forest (MPF), mixed coniferous and broadleaved forest (MF) and monsoon evergreen broadleaved forest (MEBF). Results showed that litter removal decreased litter decomposition rates by 27%, 10% and 8...

Incubation of air-pollution-control residues from secondary Pb smelter in deciduous and coniferous organic soil horizons: Leachability of lead, cadmium and zinc

Energy Technology Data Exchange (ETDEWEB)

Chrastny, Vladislav, E-mail: vladislavchrastny@seznam.cz [University of South Bohemia, Faculty of Science, Studentska 13, 370 05 Ceske Budejovice (Czech Republic); Czech University of Life Sciences Prague, Faculty of Environmental Sciences, Kamycka 129, 165 21 Prague 6 (Czech Republic); Vanek, Ales [Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Kamycka 129, 165 21 Praha 6 (Czech Republic); Komarek, Michael [Czech University of Life Sciences Prague, Faculty of Environmental Sciences, Kamycka 129, 165 21 Prague 6 (Czech Republic); Farkas, Juraj [Czech Geological Survey, Geologicka 6, 152 00 Praha 5 (Czech Republic); Drabek, Ondrej; Vokurkova, Petra [Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Kamycka 129, 165 21 Praha 6 (Czech Republic); Nemcova, Jana [University of South Bohemia, Faculty of Agriculture, Studentska 13, 370 05 Ceske Budejovice (Czech Republic)

2012-03-30

Highlights: Black-Right-Pointing-Pointer Pb smelter fly ash was incubated in forest soil horizons to assess metal mobility. Black-Right-Pointing-Pointer The metal mobilization depends on pH and the ratio of humic/fulvic acids to SOM. Black-Right-Pointing-Pointer The lowest mobilization of Pb, Zn and Cd took place in horizon H (coniferous forest). Black-Right-Pointing-Pointer A huge amount of Cd was found to have leached in the horizon F (deciduous forest). Black-Right-Pointing-Pointer More vulnerable to metal leaching from APC residues is soil from deciduous forest. - Abstract: The leachability of air-pollution-control (APC) residues from a secondary lead smelter in organic soil horizons (F and H) from a deciduous and a coniferous forest during incubation periods of 0, 3 and 6 months were compared in this work. While the concentration of Pb, Zn and Cd associated with the exchangeable/acid extractable fraction in the horizon F from the coniferous forest was higher compared to the deciduous, significantly lower concentrations in the humified horizon H was found. It is suggested that lower pH and a higher share of fulvic acids fraction (FAs) of solid phase soil organic matter (SOM) in the humified soil horizon H from the coniferous compared to the deciduous forest is responsible for a higher metal association with solid phase SOM and therefore a lower metal leaching in a soil system. From this point of view, the humified soil horizon H from the deciduous forest represents a soil system more vulnerable to Pb, Zn and Cd leaching from APC residues.

Seed longevity and dormancy state suggest management strategies for garlic mustard (Alliaria petiolata) and Japanese stiltgrass (Microstegium vimineum) in deciduous forest sites

Science.gov (United States)

Mame E. Redwood; Glenn R. Matlack; Cynthia D. Huebner

2018-01-01

An effective management plan for invasive herb populations must consider the potential for regeneration from the soil seedbank. To test chis potential, we examined two species, Japanese scilcgrass and garlic mustard, at deciduous forest sites in southeastern Ohio. Seeds were buried in nylon mesh bags and recovered at regular intervals over 24 mo. Recovered seeds were...

Quantifying the missing link between forest albedo and productivity in the boreal zone

Science.gov (United States)

Hovi, Aarne; Liang, Jingjing; Korhonen, Lauri; Kobayashi, Hideki; Rautiainen, Miina

2016-11-01

Albedo and fraction of absorbed photosynthetically active radiation (FAPAR) determine the shortwave radiation balance and productivity of forests. Currently, the physical link between forest albedo and productivity is poorly understood, yet it is crucial for designing optimal forest management strategies for mitigating climate change. We investigated the relationships between boreal forest structure, albedo and FAPAR using a radiative transfer model called Forest Reflectance and Transmittance model FRT and extensive forest inventory data sets ranging from southern boreal forests to the northern tree line in Finland and Alaska (N = 1086 plots). The forests in the study areas vary widely in structure, species composition, and human interference, from intensively managed in Finland to natural growth in Alaska. We show that FAPAR of tree canopies (FAPARCAN) and albedo are tightly linked in boreal coniferous forests, but the relationship is weaker if the forest has broadleaved admixture, or if canopies have low leaf area and the composition of forest floor varies. Furthermore, the functional shape of the relationship between albedo and FAPARCAN depends on the angular distribution of incoming solar irradiance. We also show that forest floor can contribute to over 50 % of albedo or total ecosystem FAPAR. Based on our simulations, forest albedos can vary notably across the biome. Because of larger proportions of broadleaved trees, the studied plots in Alaska had higher albedo (0.141-0.184) than those in Finland (0.136-0.171) even though the albedo of pure coniferous forests was lower in Alaska. Our results reveal that variation in solar angle will need to be accounted for when evaluating climate effects of forest management in different latitudes. Furthermore, increasing the proportion of broadleaved trees in coniferous forests is the most important means of maximizing albedo without compromising productivity: based on our findings the potential of controlling forest

Natural and near natural tropical forest values

Science.gov (United States)

Daniel H. Henning

2011-01-01

This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

Comparative seasonal variations of spectral signatures of broad-leaved and coniferous stands from Landsat data. Comparison with other perennial environments

International Nuclear Information System (INIS)

Chaume, R.; Combeau, A.

1984-01-01

Spectral signatures of two distinct forest test areas were identified from digital data including 15 LANDSAT scenes covering the same geographical area: a broad-leaved forest (oak and beech) and a coniferous forest (scotch pine). Seasonal variations of the signatures were examined and were expressed in terms of various data: date, solar height and phenological state of vegetation cover. Results were compared to these obtained from other perennial surface conditions (grassland, bare soils) . Range of the seasonal variations of radiance is noted, as well as evolutionary peculiarities on each band and between themes. Rationing of spectral bands (particularly MSS 5 and 7) and their variation with time are specified [fr

Homogeneous data-reprocessing and full synthesis of eddy-flux measurements in French terrestrial ecosytems : 1999 - 2015

Science.gov (United States)

Moreaux, V.; Ceschia, E.; Delpierre, N.; Dufrêne, E.; Joffre, R.; Klumpp, K.; Berveiller, D.; Loustau, D.; Limousin, J. M.; Ourcival, J. M.; Brut, A.; Darsonville, O.; Lafont, S.; Piquemal, K.; Longdoz, B.

2017-12-01

The attribution of the significant inter-annual variability of long lived greenhouse gas (GHG) fluxes, between edaphic, meteorological variables and ecosystem management parameters - independently or in interaction, evolving as a long term drift or as extreme events - remains uncertain. Our research aims to quantify the potential impact of climatic drifts or anthropogenic and meteorological events on ecosystem-atmosphere exchanges of French sites by analyzing the long series (at least continuous 9 years, between 1996 and 2015) of eddy covariance (EC) fluxes. We firstly performed a homogeneously repost-processing of the raw EC data across 5 sites: three forest ecosystems (deciduous broad-leaved FR-Fon, evergreen broadleaved FR-Pue, and evergreen coniferous FR-Br), one extensive grassland (FR-Lq2) and one cropland (FR-Aur). These data, in terms of net ecosystem exchanges (NEE), gross primary production (GPP) and ecosystem respiration (Reco) were put together with the corresponding climatic and edaphic data and with the carbon stock inventory for an homogeneous statistical analysis and comparative interpretations. The standard protocol, excluding any Nakai's corrections, helped to reduce the influence of the methodology and experimental design on the temporal and spatial variability. The methodology adopted finally used 35% on average of flux data for all sites. Based on the first analysis of reprocessed data from the forests, no significant long term evolution of NEE, Reco and GPP through the studied periods despite [CO2] increase and long term change observed in environmental parameters. Combining all years, a respiration limitation at high air temperature was observed on the forest sites, with a LAI dependency for deciduous ecosystems, and REW dependency for evergreen southern sites. A dominant effect of air vapor stress, compared to edaphic stress was observed on GPP response to PPFD in the deciduous northern forest, significantly decreasing with VPD increase.

Exploring Conservation Options in the Broad-Leaved Korean Pine Mixed Forest of the Changbai Mountain Region

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Lin Ma

2015-05-01

Full Text Available The broad-leaved Korean pine (Pinus koraiensis mixed forest (BKPF is one of the most biodiverse zonal communities in the northern temperate zone. Changbai Mountain in northeastern China contains one of the largest BKPFs in the region. The government of China has established a network of 23 nature reserves to protect the BKPF and the species that depend on it for habitat, including the endangered Siberian tiger (Panthera tigris altaica. This study used the conservation planning software C-Plan to calculate the irreplaceability value of each unit to assess how efficiently and comprehensively the existing conservation network supports biodiversity and to identify gap areas that, if integrated into the network, would expand its protection capability. Results show a number of high-conservation-value planning units concentrated along certain ridges. The existing conservation network is structured such that the habitats of only 24 species (out of a total of 75 achieve established conservation targets. Of the other 51 species, 20 achieve less than 50% of their conservation targets. However, expanding the network to include high-conservation-value gap areas could achieve conservation targets for 64 species and could provide different degrees of protection to the other 11 species. Using C-Plan software can guide decision-making to expand the conservation network in this most precious of mountainous ecological zones.

Ecosystem-Atmosphere Exchange of Carbon, Water and Energy over a Mixed Deciduous Forest in the Midwest

Energy Technology Data Exchange (ETDEWEB)

Danilo Dragoni; Hans Peter Schmid; C.S.B. Grimmond; J.C. Randolph; J.R. White

2012-12-17

During the project period we continued to conduct long-term (multi-year) measurements, analysis, and modeling of energy and mass exchange in and over a deciduous forest in the Midwestern United States, to enhance the understanding of soil-vegetation-atmosphere exchange of carbon. At the time when this report was prepared, results from nine years of measurements (1998 - 2006) of above canopy CO2 and energy fluxes at the AmeriFlux site in the Morgan-Monroe State Forest, Indiana, USA (see Table 1), were available on the Fluxnet database, and the hourly CO2 fluxes for 2007 are presented here (see Figure 1). The annual sequestration of atmospheric carbon by the forest is determined to be between 240 and 420 g C m-2 a-1 for the first ten years. These estimates are based on eddy covariance measurements above the forest, with a gap-filling scheme based on soil temperature and photosynthetically active radiation. Data gaps result from missing data or measurements that were rejected in qua)lity control (e.g., during calm nights). Complementary measurements of ecological variables (i.e. inventory method), provided an alternative method to quantify net carbon uptake by the forest, partition carbon allocation in each ecosystem components, and reduce uncertainty on annual net ecosystem productivity (NEP). Biometric datasets are available on the Fluxnext database since 1998 (with the exclusion of 2006). Analysis for year 2007 is under completion.

Phenology of two Ficus species in seasonal semi-deciduous forest in Southern Brazil

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E. Bianchini

Full Text Available Abstract We analyzed the phenology of Ficus adhatodifolia Schott ex Spreng. (23 fig tree and F. eximia Schott (12 fig tree for 74 months in a remnant of seasonal semi-deciduous forest (23°27’S and 51°15’W, Southern Brazil and discussed their importance to frugivorous. Leaf drop, leaf flush, syconia production and dispersal were recorded. These phenophases occurred year-round, but seasonal peaks were recorded in both leaf phenophases for F. eximia and leaf flushing for F. adhatodifolia. Climatic variables analyzed were positively correlated with reproductive phenophases of F. adhatodifolia and negatively correlated with the vegetative phenophases of F. eximia. In despite of environmental seasonality, little seasonality in the phenology of two species was observed, especially in the reproductive phenology. Both species were important to frugivorous, but F. adhatodifolia can play a relevant role in the remnant.

Study Of Plant Regeneration Potential In Tropical Moist Deciduous Forest In Northern India

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Ashish K Mishra

2013-12-01

Full Text Available Regeneration patterns of species population can address climate change by adaptive evolution or by migrating association to survive in their favorable climate and finally decided to particular forest future. In this paper we examined the status of regeneration potential of tree species in tropical moist deciduous forest at Katerniaghat Wildlife Sanctuary, Northern India. To investigate tree, sapling and seedling population distribution, we examine regeneration status in 145 random plots in study area. Total 74 plant species of 60 genera belonging to 32 families out of which 71 species of trees, 56 of seedlings and 60 of saplings were found in the forest. On the basis of importance value index Mallotus philippensis, Tectona grandis, Shorea robusta, Syzygium cumini and Bombax ceiba have been found as dominant species in the study area. As far as the regeneration status is concerned, the maximum tree species (64% have been found in good regeneration category. Significant variations in species richness and population density, between three life form (i. e. tree, sapling and seedling have been found. In which only three new tree species Prosopis juliflora, Psidium guajava and Morus alba were added in sapling and seedling stage. It is major ecological concern that about 19 % economically important plant species like Madhuca longifolia, Terminalia elliptica, Buchanania cochinchinensis, some Ficus species etc. have been found in poor regeneration phage, whereas about 7% species found in no regeneration categories. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 153-163 DOI: http://dx.doi.org/10.3126/ije.v2i1.9218

Suficiência amostral para coletas de serapilheira acumulada sobre o solo em Pinus elliottii Engelm, Eucalyptus sp. E floresta estacional decidual Adequate sampling for collection of litter accumulated on the soil in Pinus elliottii engelm, Eucalyptus sp. And seasonal deciduous forest

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Isabel Sandra Kleinpaul

2005-12-01

Full Text Available O presente estudo objetivou determinar a suficiência amostral para coletas de serapilheira acumulada sobre o solo em povoamentos de Pinus elliottii, Eucalyptus sp., ambos plantados no Campus da Universidade Federal de Santa Maria e em uma área de Floresta Estacional Decidual (FED localizada no Morro do Elefante, Santa Maria, RS. Para a realização do estudo, foram coletadas 100 amostras de serapilheira por floresta, com o auxílio de uma moldura quadrada de 25 cm de lado, totalizando 300 amostras, as quais foram separadas nas seguintes frações: acículas ou folhas, galhos, estruturas reprodutivas, cascas e resíduos. Com base nos pesos de matéria seca de cada fração, realizou-se a análise estatística dos dados, visando à estabilização dos valores do coeficiente de variação (CV%. Para Pinus elliottii, a maior contribuição na formação da serapilheira foi dada pelas acículas, com 57,2%; em Eucalyptus sp., isso ocorreu com os galhos (38,8% e na FED, novamente com as folhas, que representaram 49,6% da serapilheira. No Pinus elliottii, o maior CV% se deu nos resíduos, seguido de estruturas reprodutivas. Em Eucalyptus sp., o maior CV% foi encontrado em cascas, seguido de galhos. Na FED, as cascas tiveram o maior CV%. A suficiência amostral necessária para Pinus elliottii foi de 40, sendo esse o povoamento que necessitou de menos amostras para estabilizar o CV%. Em Eucalyptus sp., a suficiência amostral foi de 70, enquanto na FED foram necessárias 80 amostras.This study determined the sample sufficiency for the collection of litter accumulated on the soil, in Pinus elliottii and Eucalyptus sp. stands, planted in the Campus of the Federal University of Santa Maria and a Seasonal Deciduous Forest, located at the "Morro do Elefante", Santa Maria - RS. To carry out this study, 100 samples were collected per site, using a square frame (25 cm², totaling 300 samples. The samples were separated in the following fractions: needles or

DRY DEPOSITION OF POLLUTANTS TO FORESTS

Science.gov (United States)

We report on the results of an extensive field campaign to measure dry deposition of ozone and sulfur dioxide to a sample of forest types in the United States. Measurements were made for full growing seasons over a deciduous forest in Pennsylvania and a mixed deciduous-conifer...

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

International Nuclear Information System (INIS)

Zavitkovski, J.

1977-01-01

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

Habitat selection by owls in a seasonal semi-deciduous forest in southern Brazil

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W. Menq

Full Text Available Abstract This paper tested the hypothesis that the structural components of vegetation have impact over the distribution of owl species in a fragment of a semi-deciduous seasonal forest. This paper also determined which vegetation variables contributed to the spatial distribution of owl species. It was developed in the Perobas Biological Reserve (PBR between September and December 2011. To conduct the owl census, a playback technique was applied at hearing points distributed to cover different vegetation types in the study area. A total of 56 individual owls of six species were recorded: Tropical Screech-Owl (Megascops choliba, Black-capped Screech-Owl (Megascops atricapilla, Tawny-browed Owl (Pulsatrix koeniswaldiana, Ferruginous Pygmy-Owl (Glaucidium brasilianum, Mottled Owl (Strix virgata and Stygian Owl (Asio stygius. The results suggest that the variables of vegetation structure have impact on the occurrence of owls. The canopy height, the presence of hollow trees, fallen trees and glades are the most important structural components influencing owl distribution in the sampled area.

Seasonal variations of gas exchange and water relations in deciduous and evergreen trees in monsoonal dry forests of Thailand.

Science.gov (United States)

Ishida, Atsushi; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Sasrisang, Amornrat; Kaewpakasit, Kanokwan; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Gamo, Minoru; Diloksumpun, Sapit; Puangchit, Ladawan; Ishizuka, Moriyoshi

2010-08-01

This study compared leaf gas exchange, leaf hydraulic conductance, twig hydraulic conductivity and leaf osmotic potential at full turgor between two drought-deciduous trees, Vitex peduncularis Wall. and Xylia xylocarpa (Roxb.) W. Theob., and two evergreen trees, Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels, at the uppermost canopies in tropical dry forests in Thailand. The aims were to examine (i) whether leaf and twig hydraulic properties differ in relation to leaf phenology and (ii) whether xylem cavitation is a determinant of leaf shedding during the dry season. The variations in almost all hydraulic traits were more dependent on species than on leaf phenology. Evergreen Hopea exhibited the lowest leaf-area-specific twig hydraulic conductivity (leaf-area-specific K(twig)), lamina hydraulic conductance (K(lamina)) and leaf osmotic potential at full turgor (Ψ(o)) among species, whereas evergreen Syzygium exhibited the highest leaf-area-specific K(twig), K(lamina) and Ψ(o). Deciduous Xylia had the highest sapwood-area-specific K(twig), along with the lowest Huber value (sapwood area/leaf area). More negative osmotic Ψ(o) and leaf osmotic adjustment during the dry season were found in deciduous Vitex and evergreen Hopea, accompanied by low sapwood-area-specific K(twig). Regarding seasonal changes in hydraulics, no remarkable decrease in K(lamina) and K(twig) was found during the dry season in any species. Results suggest that leaf shedding during the dry season is not always associated with extensive xylem cavitation.

Observing Spring and Fall Phenology in a Deciduous Forest with Aerial Drone Imagery

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Stephen Klosterman

2017-12-01

Full Text Available Plant phenology is a sensitive indicator of the effects of global change on terrestrial ecosystems and controls the timing of key ecosystem functions including photosynthesis and transpiration. Aerial drone imagery and photogrammetric techniques promise to advance the study of phenology by enabling the creation of distortion-free orthomosaics of plant canopies at the landscape scale, but with branch-level image resolution. The main goal of this study is to determine the leaf life cycle events corresponding to phenological metrics derived from automated analyses based on color indices calculated from drone imagery. For an oak-dominated, temperate deciduous forest in the northeastern USA, we find that plant area index (PAI correlates with a canopy greenness index during spring green-up, and a canopy redness index during autumn senescence. Additionally, greenness and redness metrics are significantly correlated with the timing of budburst and leaf expansion on individual trees in spring. However, we note that the specific color index for individual trees must be carefully chosen if new foliage in spring appears red, rather than green—which we observed for some oak trees. In autumn, both decreasing greenness and increasing redness correlate with leaf senescence. Maximum redness indicates the beginning of leaf fall, and the progression of leaf fall correlates with decreasing redness. We also find that cooler air temperature microclimates near a forest edge bordering a wetland advance the onset of senescence. These results demonstrate the use of drones for characterizing the organismic-level variability of phenology in a forested landscape and advance our understanding of which phenophase transitions correspond to color-based metrics derived from digital image analysis.

Observing Spring and Fall Phenology in a Deciduous Forest with Aerial Drone Imagery.

Science.gov (United States)

Klosterman, Stephen; Richardson, Andrew D

2017-12-08

Plant phenology is a sensitive indicator of the effects of global change on terrestrial ecosystems and controls the timing of key ecosystem functions including photosynthesis and transpiration. Aerial drone imagery and photogrammetric techniques promise to advance the study of phenology by enabling the creation of distortion-free orthomosaics of plant canopies at the landscape scale, but with branch-level image resolution. The main goal of this study is to determine the leaf life cycle events corresponding to phenological metrics derived from automated analyses based on color indices calculated from drone imagery. For an oak-dominated, temperate deciduous forest in the northeastern USA, we find that plant area index (PAI) correlates with a canopy greenness index during spring green-up, and a canopy redness index during autumn senescence. Additionally, greenness and redness metrics are significantly correlated with the timing of budburst and leaf expansion on individual trees in spring. However, we note that the specific color index for individual trees must be carefully chosen if new foliage in spring appears red, rather than green-which we observed for some oak trees. In autumn, both decreasing greenness and increasing redness correlate with leaf senescence. Maximum redness indicates the beginning of leaf fall, and the progression of leaf fall correlates with decreasing redness. We also find that cooler air temperature microclimates near a forest edge bordering a wetland advance the onset of senescence. These results demonstrate the use of drones for characterizing the organismic-level variability of phenology in a forested landscape and advance our understanding of which phenophase transitions correspond to color-based metrics derived from digital image analysis.

Incubation of air-pollution-control residues from secondary Pb smelter in deciduous and coniferous organic soil horizons: leachability of lead, cadmium and zinc.

Science.gov (United States)

Chrastný, Vladislav; Vaněk, Aleš; Komárek, Michael; Farkaš, Juraj; Drábek, Ondřej; Vokurková, Petra; Němcová, Jana

2012-03-30

The leachability of air-pollution-control (APC) residues from a secondary lead smelter in organic soil horizons (F and H) from a deciduous and a coniferous forest during incubation periods of 0, 3 and 6 months were compared in this work. While the concentration of Pb, Zn and Cd associated with the exchangeable/acid extractable fraction in the horizon F from the coniferous forest was higher compared to the deciduous, significantly lower concentrations in the humified horizon H was found. It is suggested that lower pH and a higher share of fulvic acids fraction (FAs) of solid phase soil organic matter (SOM) in the humified soil horizon H from the coniferous compared to the deciduous forest is responsible for a higher metal association with solid phase SOM and therefore a lower metal leaching in a soil system. From this point of view, the humified soil horizon H from the deciduous forest represents a soil system more vulnerable to Pb, Zn and Cd leaching from APC residues. Copyright © 2012 Elsevier B.V. All rights reserved.

Deciduous birch canopy as unexpected contributor to stand level atmospheric reactivity in boreal forests

Science.gov (United States)

Bäck, Jaana; Taipale, Ditte; Aalto, Juho

2017-04-01

In boreal forests, deciduous trees such as birches may in future climate become more abundant due to their large biomass production capacity, relatively good resource use ability and large acclimation potential to elevated CO2 levels and warmer climate. Increase in birch abundance may lead to unpredicted consequences in atmospheric composition. Currently it is acknowledged that conifers such as Scots pine and Norway spruce are important sources for volatile organic compounds (VOCs), especially monoterpenes, throughout the year, although the strong temperature relationships implies that emissions are highest in summertime. However, the dynamics of the deciduous birch foliage VOC emissions and their relationship with environmental drivers during the development, maturation and senescence of foliage has not been well analyzed. Long-term measurements of birch, which are unfortunately very sparse, can provide very useful information for the development of biosphere-atmosphere models that simulate boreal and subarctic forested areas where birch is often a sub-canopy species, occurs as a mixture among conifers or forms even pure stands in the higher latitudes. We measured the branch level VOC emissions from a mature Silver birch with proton transfer reaction mass spectrometer during 2014 and 2015 at the SMEAR II station (Station for Measuring Ecosystem-Atmosphere Relations), southern Finland. Our results showed that the Silver birch foliage is a huge source for both short-chained volatiles such as methanol, acetaldehyde and acetone, as well as for monoterpenes. The mean emission rates from birch leaves were 5 to 10 times higher than the corresponding emissions from Scots pine shoots. We compared several semi-empirical model approaches for determining the birch foliage monoterpene standardized emission potentials, and utilized the continuous emission measurements from the two growing seasons for development of a novel algorithm which accounts for the leaf development and

Polarimetric SAR Interferometry based modeling for tree height and aboveground biomass retrieval in a tropical deciduous forest

Science.gov (United States)

Kumar, Shashi; Khati, Unmesh G.; Chandola, Shreya; Agrawal, Shefali; Kushwaha, Satya P. S.

2017-08-01

The regulation of the carbon cycle is a critical ecosystem service provided by forests globally. It is, therefore, necessary to have robust techniques for speedy assessment of forest biophysical parameters at the landscape level. It is arduous and time taking to monitor the status of vast forest landscapes using traditional field methods. Remote sensing and GIS techniques are efficient tools that can monitor the health of forests regularly. Biomass estimation is a key parameter in the assessment of forest health. Polarimetric SAR (PolSAR) remote sensing has already shown its potential for forest biophysical parameter retrieval. The current research work focuses on the retrieval of forest biophysical parameters of tropical deciduous forest, using fully polarimetric spaceborne C-band data with Polarimetric SAR Interferometry (PolInSAR) techniques. PolSAR based Interferometric Water Cloud Model (IWCM) has been used to estimate aboveground biomass (AGB). Input parameters to the IWCM have been extracted from the decomposition modeling of SAR data as well as PolInSAR coherence estimation. The technique of forest tree height retrieval utilized PolInSAR coherence based modeling approach. Two techniques - Coherence Amplitude Inversion (CAI) and Three Stage Inversion (TSI) - for forest height estimation are discussed, compared and validated. These techniques allow estimation of forest stand height and true ground topography. The accuracy of the forest height estimated is assessed using ground-based measurements. PolInSAR based forest height models showed enervation in the identification of forest vegetation and as a result height values were obtained in river channels and plain areas. Overestimation in forest height was also noticed at several patches of the forest. To overcome this problem, coherence and backscatter based threshold technique is introduced for forest area identification and accurate height estimation in non-forested regions. IWCM based modeling for forest

impact of re-forestation of a re-growth secondary forest with

African Journals Online (AJOL)

BIG TIMMY

In general, the forest stand had more density of trees in each dbh class with a peak in .... Awolowo University Estate, Ile-Ife, Osun state, ... forest sub-type is dry deciduous forest (Onochie, ..... eastern Cascades, USA. .... Agriculture, Washington.

Landscape composition influences abundance patterns and habitat use of three ungulate species in fragmented secondary deciduous tropical forests, Mexico

Directory of Open Access Journals (Sweden)

G. García-Marmolejo

2015-01-01

Full Text Available Secondary forests are extensive in the tropics. Currently, these plant communities are the available habitats for wildlife and in the future they will possibly be some of the most wide-spread ecosystems world-wide. To understand the potential role of secondary forests for wildlife conservation, three ungulate species were studied: Mazama temama, Odocoileus virginianus and Pecari tajacu. We analyzed their relative abundance and habitat use at two spatial scales: (1 Local, where three different successional stages of tropical deciduous forest were compared, and (2 Landscape, where available habitats were compared in terms of landscape composition (proportion of forests, pastures and croplands within 113 ha. To determine the most important habitat-related environmental factors influencing the Sign Encounter Rate (SER of the three ungulate species, 11 physical, anthropogenic and vegetation variables were simultaneously analyzed through model selection using Akaike’s Information Criterion. We found, that P. tajacu and O. virginianus mainly used early successional stages, while M. temama used all successional stages in similar proportions. The latter species, however, used early vegetation stages only when they were located in landscapes mainly covered by forest (97%. P. tajacu and O. virginianus also selected landscapes covered essentially by forests, although they required smaller percentages of forest (86%. All ungulate species avoided landscape fragments covered by pastures. For all three species, landscape composition and human activities were the variables that best explained SER. We concluded that landscape is the fundamental scale for ungulate management, and that secondary forests are potentially important landscape elements for ungulate conservation.

Holocene vegetation and fire history of the mountains of northern Sicily (Italy)

Science.gov (United States)

Tinner, Willy; Vescovi, Elisa; Van Leeuwen, Jacqueline; Colombaroli, Daniele; Henne, Paul; Kaltenrieder, Petra; Morales-Molino, Cesar; Beffa, Giorgia; Gnaegi, Bettina; Van der Knaap, Pim W O; La Mantia, Tommaso; Pasta, Salvatore

2016-01-01

Knowledge about vegetation and fire history of the mountains of Northern Sicily is scanty. We analysed five sites to fill this gap and used terrestrial plant macrofossils to establish robust radiocarbon chronologies. Palynological records from Gorgo Tondo, Gorgo Lungo, Marcato Cixé, Urgo Pietra Giordano and Gorgo Pollicino show that under natural or near natural conditions, deciduous forests (Quercus pubescens, Q. cerris, Fraxinus ornus, Ulmus), that included a substantial portion of evergreen broadleaved species (Q. suber, Q. ilex, Hedera helix), prevailed in the upper meso-mediterranean belt. Mesophilous deciduous and evergreen broadleaved trees (Fagus sylvatica, Ilex aquifolium) dominated in the natural or quasi-natural forests of the oro-mediterranean belt. Forests were repeatedly opened for agricultural purposes. Fire activity was closely associated with farming, providing evidence that burning was a primary land use tool since Neolithic times. Land use and fire activity intensified during the Early Neolithic at 5000 bc, at the onset of the Bronze Age at 2500 bc and at the onset of the Iron Age at 800 bc. Our data and previous studies suggest that the large majority of open land communities in Sicily, from the coastal lowlands to the mountain areas below the thorny-cushion Astragalus belt (ca. 1,800 m a.s.l.), would rapidly develop into forests if land use ceased. Mesophilous Fagus-Ilex forests developed under warm mid Holocene conditions and were resilient to the combined impacts of humans and climate. The past ecology suggests a resilience of these summer-drought adapted communities to climate warming of about 2 °C. Hence, they may be particularly suited to provide heat and drought-adaptedFagus sylvatica ecotypes for maintaining drought-sensitive Central European beech forests under global warming conditions.

Predicting vegetation type through physiological and environmental interactions with leaf traits: evergreen and deciduous forests in an earth system modeling framework.

Science.gov (United States)

Weng, Ensheng; Farrior, Caroline E; Dybzinski, Ray; Pacala, Stephen W

2017-06-01

Earth system models are incorporating plant trait diversity into their land components to better predict vegetation dynamics in a changing climate. However, extant plant trait distributions will not allow extrapolations to novel community assemblages in future climates, which will require a mechanistic understanding of the trade-offs that determine trait diversity. In this study, we show how physiological trade-offs involving leaf mass per unit area (LMA), leaf lifespan, leaf nitrogen, and leaf respiration may explain the distribution patterns of evergreen and deciduous trees in the temperate and boreal zones based on (1) an evolutionary analysis of a simple mathematical model and (2) simulation experiments of an individual-based dynamic vegetation model (i.e., LM3-PPA). The evolutionary analysis shows that these leaf traits set up a trade-off between carbon- and nitrogen-use efficiency at the scale of individual trees and therefore determine competitively dominant leaf strategies. As soil nitrogen availability increases, the dominant leaf strategy switches from one that is high in nitrogen-use efficiency to one that is high in carbon-use efficiency or, equivalently, from high-LMA/long-lived leaves (i.e., evergreen) to low-LMA/short-lived leaves (i.e., deciduous). In a region of intermediate soil nitrogen availability, the dominant leaf strategy may be either deciduous or evergreen depending on the initial conditions of plant trait abundance (i.e., founder controlled) due to feedbacks of leaf traits on soil nitrogen mineralization through litter quality. Simulated successional patterns by LM3-PPA from the leaf physiological trade-offs are consistent with observed successional dynamics of evergreen and deciduous forests at three sites spanning the temperate to boreal zones. © 2016 John Wiley & Sons Ltd.

Using Remote Sensing Products for Environmental Analysis in South America

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Fabrício Brito Silva

2011-09-01

Full Text Available Land cover plays a major role in many biogeochemical models that represent processes and connections with terrestrial systems; hence, it is a key component for public decisions in ecosystems management. The advance of remote sensing technology, combined with the emergence of new operational products, offers alternatives to improve the accuracy of environmental monitoring and analysis. This work uses the GLOBCOVER, the Vegetation Continuous Field (VCF, MODIS Fire Radiative Power (FRP and the Tropical Rainfall Measuring Mission (TRMM remotely sensed databases to analyze the biomass burning distribution, the land use and land cover characteristics and the percent of tree cover in South America during the years 2000 to 2005. Initially, GLOBCOVER was assessed based on VCF product, and subsequently used for quantitative analysis of the spatial distribution of the South America fires with the fire radiative power (FRP. The results show that GLOBCOVER has a tendency to overestimate forest classes and to underestimate urban and mangroves areas. The fire quantification based on GLOBCOVER product shows that the highest incidence of fires can be observed in the arc of deforestation, located in the Amazon forest border, with vegetation cover composed mainly of broadleaved evergreen or semi-deciduous forest. A time series analysis of FRP database indicates that biomass burning occurs mainly in areas of broadleaved evergreen or semi-deciduous forest and in Brazilian Cerrado associated with grassland management, agricultural land clearing and with the deforestation of Amazon tropical rainforest. Also, variations in FRP intensity and spread can be attributed to rainfall anomalies, such as in 2004, when South America had a positive anomaly rainfall.

A comparison of 137Cs radioactivity in localized evergreen and deciduous plant species

International Nuclear Information System (INIS)

Rangel, R.C.

1996-05-01

A vegetation study at the Comanche Peak Steam Electric Station (CPSES) near Glen Rose, Texas was conducted in 1991 and 1992. The CPSES is a commercial nuclear power plant owned and operated by Texas Utilities Electric of Dallas, Texas. The US Nuclear Regulatory Commission (USNRC) requires the CPSES to routinely sample broadleaf vegetation in place of milk samples. Few commercial dairies exist in the vicinity. Broadleaf tree species are scarce because the climate and local limestone geology have produced a dry rolling hill topography. An evergreen juniper is the dominant tree species. Few broadleaves during the winter season have hindered year-round sampling. This study compares the environmental 137 Cs concentrations between broadleaf and evergreen foliage at CPSES. Soil 137 Cs concentrations from each vegetation location were also compared to the foliage 137 Cs concentrations. The study's objective was to determine if the deciduous and evergreen vegetation 137 Cs concentrations are statistically the same

MODIS-derived EVI, NDVI and WDRVI time series to estimate phenological metrics in French deciduous forests

Science.gov (United States)

Testa, S.; Soudani, K.; Boschetti, L.; Borgogno Mondino, E.

2018-02-01

Monitoring forest phenology allows us to study the effects of climate change on vegetated land surfaces. Daily and composite time series (TS) of several vegetation indices (VIs) from MODerate resolution Imaging Spectroradiometer (MODIS) data have been widely used in scientific works for phenological studies since the beginning of the MODIS mission. The objective of this work was to use MODIS data to find the best VI/TS combination to estimate start-of-season (SOS) and end-of-season (EOS) dates across 50 temperate deciduous forests. Our research used as inputs 2001-2012 daily reflectance from MOD09GQ/MOD09GA products and 16-day composite VIs from the MOD13Q1 dataset. The 50 pixels centered on the 50 forest plots were extracted from the above-mentioned MODIS imagery; we then generated 5 different types of TS (1 daily from MOD09 and 4 composite from MOD13Q1) and used all of them to implement 6 VIs, obtaining 30 VI/TS combinations. SOS and EOS estimates were determined for each pixel/year and each VI/TS combination. SOS/EOS estimations were then validated against ground phenological observations. Results showed that, in our test areas, composite TS, if actual acquisition date is considered, performed mostly better than daily TS. EVI, WDRVI0.20 and NDVI were more suitable to SOS estimation, while WDRVI0.05 and EVI were more convenient in estimating early and advanced EOS, respectively.

Estimating Stand Volume and Above-Ground Biomass of Urban Forests Using LiDAR

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Vincenzo Giannico

2016-04-01

Full Text Available Assessing forest stand conditions in urban and peri-urban areas is essential to support ecosystem service planning and management, as most of the ecosystem services provided are a consequence of forest stand characteristics. However, collecting data for assessing forest stand conditions is time consuming and labor intensive. A plausible approach for addressing this issue is to establish a relationship between in situ measurements of stand characteristics and data from airborne laser scanning (LiDAR. In this study we assessed forest stand volume and above-ground biomass (AGB in a broadleaved urban forest, using a combination of LiDAR-derived metrics, which takes the form of a forest allometric model. We tested various methods for extracting proxies of basal area (BA and mean stand height (H from the LiDAR point-cloud distribution and evaluated the performance of different models in estimating forest stand volume and AGB. The best predictors for both models were the scale parameters of the Weibull distribution of all returns (except the first (proxy of BA and the 95th percentile of the distribution of all first returns (proxy of H. The R2 were 0.81 (p < 0.01 for the stand volume model and 0.77 (p < 0.01 for the AGB model with a RMSE of 23.66 m3·ha−1 (23.3% and 19.59 Mg·ha−1 (23.9%, respectively. We found that a combination of two LiDAR-derived variables (i.e., proxy of BA and proxy of H, which take the form of a forest allometric model, can be used to estimate stand volume and above-ground biomass in broadleaved urban forest areas. Our results can be compared to other studies conducted using LiDAR in broadleaved forests with similar methods.

Effects of a windthrow disturbance on the carbon balance of a broadleaf deciduous forest in Hokkaido, Japan

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K. Yamanoi

2015-12-01

Full Text Available Forests play an important role in the terrestrial carbon balance, with most being in a carbon sequestration stage. The net carbon releases that occur result from forest disturbance, and windthrow is a typical disturbance event affecting the forest carbon balance in eastern Asia. The CO2 flux has been measured using the eddy covariance method in a deciduous broadleaf forest (Japanese white birch, Japanese oak, and castor aralia in Hokkaido, where incidental damage by the strong Typhoon Songda in 2004 occurred. We also used the biometrical method to demonstrate the CO2 flux within the forest in detail. Damaged trees amounted to 40 % of all trees, and they remained on site where they were not extracted by forest management. Gross primary production (GPP, ecosystem respiration (Re, and net ecosystem production were 1350, 975, and 375 g C m−2 yr−1 before the disturbance and 1262, 1359, and −97 g C m−2 yr−1 2 years after the disturbance, respectively. Before the disturbance, the forest was an evident carbon sink, and it subsequently transformed into a net carbon source. Because of increased light intensity at the forest floor, the leaf area index and biomass of the undergrowth (Sasa kurilensis and S. senanensis increased by factors of 2.4 and 1.7, respectively, in 3 years subsequent to the disturbance. The photosynthesis of Sasa increased rapidly and contributed to the total GPP after the disturbance. The annual GPP only decreased by 6 % just after the disturbance. On the other hand, the annual Re increased by 39 % mainly because of the decomposition of residual coarse-wood debris. The carbon balance after the disturbance was controlled by the new growth and the decomposition of residues. The forest management, which resulted in the dead trees remaining at the study site, strongly affected the carbon balance over the years. When comparing the carbon uptake efficiency at the study site with that at others, including those with various kinds

Tree growth response to climate change at the deciduous-boreal forest ecotone, Ontario, Canada

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Goldblum, D. [Wisconsin-Whitewater Univ., Whitewater, WI (United States). Dept. of Geography and Geology; Rigg, L.S. [Northern Illinois Univ., DeKalb, IL (United States). Dept. of Geography

2005-11-01

Recent interest in the impact that future climate change may have on forest communities can be attributed to the fact that migration of tree species has been slow with respect to past climate changes and also because of the high degree of habitat fragmentation that has occurred in the recent past. For that reason, this study examined the implications of climate change on the future of sugar maple, white spruce and balsam fir. These trees represent the 3 dominant forest species at the deciduous-boreal forest ecotone in Ontario, Canada. The analysis was based on the responses of individual species to past monthly temperature and precipitation conditions as well as simulated monthly temperature and precipitation conditions in the study area for the 2080s. The sensitivity of the tree species to past climate with predicted conditions for the 2080 period was also considered. In particular, tree-ring analysis was used to compare local species-specific growth responses with instrumental climate records since 1900 to determine which climate variables control growth rates of these 3 species. Present temperature and precipitation averages were compared with general circulation model (GCM) predictions of monthly temperature and monthly precipitation to evaluate the potential benefit or harm to the dominant tree species over the next 80 years. It was concluded that sugar maple may persist in the medium term up to several centuries, as existing trees pass through their natural life-span without reproductive replacement. However, with extreme climate change, over many centuries, even the sugar maple at this northern range limit might be in jeopardy. White spruce is likely to benefit less, and the dominant balsam fir is likely to experience a decrease in growth potential. These projected changes would enhance the future status of sugar maple at its northern limit and facilitate range expansion northward in response to global warming. Although the study concerns only a small area

Estudo fenológico em três fases sucessionais de uma floresta estacional decidual no município de Santa Tereza, RS, Brasil Phenology study in three successional stages of a seasonal deciduous forest in Santa Tereza, RS, Brazil

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Cáren Andreis

2005-02-01

Full Text Available O presente estudo foi realizado em 40 parcelas de área fixa pertencentes a três estágios sucessionais, denominados: Capoeirão, Floresta Secundária e Floresta Madura, em uma Floresta Estacional Decidual no município de Santa Tereza, RS. Foram realizadas observações fenológicas quinzenais em 53 espécies arbóreas, numa média de 8,4 indivíduos por espécie, durante o período de 16 de novembro de 2001 a 10 de novembro de 2002. As fenofases observadas foram floração, frutificação e mudança foliar. Os resultados indicaram que a atividade reprodutiva manteve uma porcentagem relativamente baixa nos três estágios sucessionais durante o período observado, com tendências em ser menor durante a estação de inverno. A quantidade total de folhas na árvore, não se distinguindo estágio sucessional, diminuiu de aproximadamente 85% no período de maior atividade vegetativa para até 35% no inverno, período de repouso, sendo a Floresta Madura a subsere, que manteve os maiores porcentuais de folhas durante o período estudado.The present study was accomplished in forty permanent plots belonging to three forest successional stages, denominated: Brush Forest, Secondary Forest and Mature Forest, in a seasonal deciduous forest in the municipal district of Santa Tereza, RS, Brazil. Phenologic observations were accomplished fortnightly for 53 arboreal species, in an average of 8,4 individuals per species, during the period of November 2001 to November 2002. The stages observed were flowering, fruiting and foliage change. The results indicate that the reproductive activity remained relatively low for three successional stages during the observed period, with a tendency to be even lower during winter. The total amount of leaves on the trees, regardless of the successional stage, decreased from approximately 85%, in the period of higher vegetative activity, to 35% in the winter, resting season. The Mature Forest maintained the largest percentage

[Carbon storage of forest stands in Shandong Province estimated by forestry inventory data].

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Li, Shi-Mei; Yang, Chuan-Qiang; Wang, Hong-Nian; Ge, Li-Qiang

2014-08-01

Based on the 7th forestry inventory data of Shandong Province, this paper estimated the carbon storage and carbon density of forest stands, and analyzed their distribution characteristics according to dominant tree species, age groups and forest category using the volume-derived biomass method and average-biomass method. In 2007, the total carbon storage of the forest stands was 25. 27 Tg, of which the coniferous forests, mixed conifer broad-leaved forests, and broad-leaved forests accounted for 8.6%, 2.0% and 89.4%, respectively. The carbon storage of forest age groups followed the sequence of young forests > middle-aged forests > mature forests > near-mature forests > over-mature forests. The carbon storage of young forests and middle-aged forests accounted for 69.3% of the total carbon storage. Timber forest, non-timber product forest and protection forests accounted for 37.1%, 36.3% and 24.8% of the total carbon storage, respectively. The average carbon density of forest stands in Shandong Province was 10.59 t x hm(-2), which was lower than the national average level. This phenomenon was attributed to the imperfect structure of forest types and age groups, i. e., the notably higher percentage of timber forests and non-timber product forest and the excessively higher percentage of young forests and middle-aged forest than mature forests.

Response of Termite (Blattodea: Termitoidae) Assemblages to Lower Subtropical Forest Succession: A Case Study in Dinghushan Biosphere Reserve, China.

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Li, Zhi-Qiang; Ke, Yun-Ling; Zeng, Wen-Hui; Zhang, Shi-Jun; Wu, Wen-Jing

2016-02-01

Termite (Blattodea: Termitoidae) assemblages have important ecological functions and vary in structure between habitats, but have not been studied in lower subtropical forests. To examine whether differences in the richness and relative abundance of termite species and functional groups occur in lower subtropical regions, termite assemblages were sampled in Dinghushan Biosphere Reserve, China, among pine forest, pine and broad-leaved mixed forest (mixed forest), and monsoon evergreen broad-leaved forest (monsoon forest). The dominant functional group was wood-feeding termites (family Termitidae), and the mixed forest hosted the greatest richness and relative abundance. Soil-feeding termites were absent from the lower subtropical system, while humus-feeding termites were sporadically distributed in mixed forest and monsoon forest. The species richness and functional group abundance of termites in our site may be linked to the forest succession. Altitude, soil temperature, air temperature, surface air relative humidity, and litter depth were significant influences on species and functional group diversity.

Hyper-temporal c-band SAR for baseline woody structural assessments in deciduous savannas

CSIR Research Space (South Africa)

Mathieu, Renaud SA

2016-08-01

Full Text Available deciduous savanna environment. Results showed that: the temporal filter reduced image variance; the random forest model out-performed the linear model; while the TCV metric consistently showed marginally higher accuracies than the TCC metric. Combinations...

Missing ozone-induced potential aerosol formation in a suburban deciduous forest

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Nakayama, T.; Kuruma, Y.; Matsumi, Y.; Morino, Y.; Sato, K.; Tsurumaru, H.; Ramasamy, S.; Sakamoto, Y.; Kato, S.; Miyazaki, Y.; Mochizuki, T.; Kawamura, K.; Sadanaga, Y.; Nakashima, Y.; Matsuda, K.; Kajii, Y.

2017-12-01

As a new approach to investigating formation processes of secondary organic aerosol (SOA) in the atmosphere, ozone-induced potential aerosol formation was measured in summer at a suburban forest site surrounded by deciduous trees, near Tokyo, Japan. After passage through a reactor containing high concentrations of ozone, increases in total particle volume (average of 1.4 × 109 nm3/cm3, which corresponds to 17% that of pre-existing particles) were observed, especially during daytime. The observed aerosol formations were compared with the results of box model simulations using simultaneously measured concentrations of gaseous and particulate species. According to the model, the relative contributions of isoprene, monoterpene, and aromatic hydrocarbon oxidation to SOA formation in the reactor were 24, 21, and 55%, respectively. However, the model could explain, on average, only ∼40% of the observed particle formation, and large discrepancies between the observations and model were found, especially around noon and in the afternoon when the concentrations of isoprene and oxygenated volatile organic compounds were high. The results suggest a significant contribution of missing (unaccounted-for) SOA formation processes from identified and/or unidentified volatile organic compounds, especially those emitted during daytime. Further efforts should be made to explore and parameterize this missing SOA formation to assist in the improvement of atmospheric chemistry and climate models.

Outbreaks of forest defoliating insects in Japan, 1950-2000.

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Kamata, N; Kamata, N

2002-04-01

In Japan, several forest-defoliating insects reach outbreak levels and cause serious defoliation. Stand mortality sometimes occurs after severe defoliation. However, in general, tree mortality caused by insect defoliation is low because of the prevailing moist climate in Japan. Evergreen conifers are more susceptible to tree mortality as a result of insect defoliation whereas deciduous broad-leaved trees are seldom killed. Insect defoliation occurs more frequently in man-made environments such as among shade trees, orchards, and plantations than in natural habitats. Outbreaks of some defoliators tend to occur in stands of a particular age: e.g. outbreaks of the pine caterpillar, Dendrolimus spectabilis Butler (Lepidoptera: Lasiocampidae) occur more frequently in young pine plantations. In contrast, defoliation caused by outbreaks of lepidopterous and hymenopterous pests in larch plantations is more frequent with stand maturation. There is a relationship between outbreaks of some defoliators and altitude above sea level. Most outbreaks of forest defoliators were terminated by insect pathogens that operated in a density-dependent fashion. Since the 1970s, Japan has been prosperous and can afford to buy timber from abroad. More recently, there has been an increasing demand for timber in Japan, that coincides with a huge demand internationally, so that the country will need to produce more timber locally in the future. The increasing pressure on the forestry industry to meet this demand will require more sophisticated methods of pest control coupled with more sustainable methods of silviculture.

Land use change detection in Solan Forest Division, Himachal Pradesh, India

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Shipra Shah

2015-09-01

Full Text Available Background Monitoring the changing pattern of vegetation across diverse landscapes through remote sensing is instrumental in understanding the interactions of human activities and the ecological environment. Land use pattern in the state of Himachal Pradesh in the Indian Western Himalayas has been undergoing rapid modifications due to changing cropping patterns, rising anthropogenic pressure on forests and government policies. We studied land use change in Solan Forest Division of Himachal Pradesh to assess species wise area changes in the forests of the region. Methods The supervised classification (Maximum likelihood on two dates of IRS (LISS III satellite data was performed to assess land use change over the period 1998–2010. Results Seven land use categories were identified namely, chir pine (Pinus roxburghii forest, broadleaved forest, bamboo (Dendrocalamus strictus forest, ban oak (Quercus leucotrichophora forest, khair (Acacia catechu forest, culturable blank and cultivation. The area under chir pine, cultivation and khair forests increased by 191 ha (4.55 %, 129 ha (13.81 % and 77 ha (23.40 %, whereas the area under ban oak, broadleaved, culturable blank and bamboo decreased by 181 ha (16.58 %, 152 ha (6.30 %, 71 ha (2.72 % and 7 ha (0.47 %, respectively. Conclusions The study revealed a decrease in the area under forest and culturable blank categories and a simultaneous increase in the area under cultivation primarily due to the large scale introduction of horticultural cash crops in the state. The composition of forests also exhibited some major changes, with an increase in the area of commercially important monoculture plantation species such as pine and khair, and a decline in the area of oak, broadleaved and bamboo which are facing a high anthropogenic pressure in meeting the livelihood demands of forest dependent communities. In time deforestation, forest degradation and ecological imbalances due to the changing forest species

[Soil infiltration characteristics under main vegetation types in Anji County of Zhejiang Province].

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Liu, Dao-Ping; Chen, San-Xiong; Zhang, Jin-Chi; Xie, Li; Jiang, Jiang

2007-03-01

The study on the soil infiltration under different main vegetation types in Anji County of Zhejiang Province showed that the characteristics of soil infiltration differed significantly with land use type, and the test eight vegetation types could be classified into four groups, based on soil infiltration capability. The first group, deciduous broadleaved forest, had the strongest soil infiltration capability, and the second group with a stronger soil infiltration capability was composed of grass, pine forest, shrub community and tea bush. Bamboo and evergreen broadleaved forest were classified into the third group with a relatively strong soil infiltration capability, while bare land belonged to the fourth group because of the bad soil structure and poorest soil infiltration capability. The comprehensive parameters of soil infiltration (alpha) and root (beta) were obtained by principal component analysis, and the regression model of alpha and beta could be described as alpha = 0. 1708ebeta -0. 3122. Soil infiltration capability was greatly affected by soil physical and chemical characteristics and root system. Fine roots (soil physical and chemical properties, and the increase of soil infiltration capability was closely related to the amount of the fine roots.

The effect of interspecific variation in photosynthetic plasticity on 4-year growth rate and 8-year survival of understorey tree seedlings in response to gap formations in a cool-temperate deciduous forest.

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Oguchi, Riichi; Hiura, Tsutom; Hikosaka, Kouki

2017-08-01

Gap formation increases the light intensity in the forest understorey. The growth responses of seedlings to the increase in light availability show interspecific variation, which is considered to promote biodiversity in forests. At the leaf level, some species increase their photosynthetic capacity in response to gap formation, whereas others do not. Here we address the question of whether the interspecific difference in the photosynthetic response results in the interspecific variation in the growth response. If so, the interspecific difference in photosynthetic response would also contribute to species coexistence in forests. We also address the further relevant question of why some species do not increase their photosynthetic capacity. We assumed that some cost of photosynthetic plasticity may constrain acquisition of the plasticity in some species, and hypothesized that species with larger photosynthetic plasticity exhibit better growth after gap formation and lower survivorship in the shade understorey of a cool-temperate deciduous forest. We created gaps by felling canopy trees and studied the relationship between the photosynthetic response and the subsequent growth rate of seedlings. Naturally growing seedlings of six deciduous woody species were used and their mortality was examined for 8 years. The light-saturated rate of photosynthesis (Pmax) and the relative growth rate (RGR) of the seedlings of all study species increased at gap plots. The extent of these increases varied among the species. The stimulation of RGR over 4 years after gap formation was strongly correlated with change in photosynthetic capacity of newly expanded leaves. The increase in RGR and Pmax correlated with the 8-year mortality at control plots. These results suggest a trade-off between photosynthetic plasticity and the understorey shade tolerance. Gap-demanding species may acquire photosynthetic plasticity, sacrificing shade tolerances, whereas gap-independent species may acquire

Water cycle observations in forest watersheds of Cambodia

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Shimizu, A.; Tamai, K.; Kabeya, N.; Shimizu, T.; Iida, S. I.

2015-12-01

The Lower Mekong River flows through Cambodia, where forests cover ~60% of the country and are believed to have a marked effect on the water cycle. These tropical seasonal forests in the Cambodian flat lands are very precious in the Indochinese Peninsula as few forests of this type remain. However, few hydrological observations have been conducted in these areas. In Cambodia, deciduous and evergreen forests make up 42% and 33% of the total forest area, respectively. We established experimental watersheds both in deciduous and evergreen forests containing meteorological observation towers in Cambodia and collected various observational data since 2003 (O'Krieng, deciduous forest watershed including a 30-m-high observation tower, 2,245 km2; Stung Chinit, evergreen forest watershed including a 60-m-high observation tower, 3,700 km2 including three small watersheds). The basic data from these sites included various kinds of information related to the composition of vegetation, soil characteristics, etc. Hydrologic data was collected and linked to the above data; the main hydrologic research results follow. The water budget for each watershed was determined using an observational rainfall and runoff dataset. The evapotranspiration rate in an evergreen forest was obtained using various observational methods including the Bowen energy-balance ratio and the bandpass eddy covariance method. The annual evapotranspiration of evergreen forests, estimated using the Bowen energy-balance ratio method and water balance, was about 1100-1200 mm, corresponding to 70-80% of annual rainfall. While considering the importance of the presence of evergreen forest, we conducted sap flow measurements to analyze the transpiration process that maintains water uptake through root systems that reach to depths exceeding 8 m. Characteristics of the evaporation from the forest floor that form an important element of the evaporation system were estimated in both evergreen and deciduous forests.

Monitoring phenology of photosynthesis in temperate evergreen and mixed deciduous forests using the normalized difference vegetation index (NDVI) and the photochemical reflectance index (PRI) at leaf and canopy scales

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Wong, C. Y.; Arain, M. A.; Ensminger, I.

2016-12-01

Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which determines their phenology of high photosynthetic activity in the growing season and downregulation during the winter. Monitoring the timing of the transition between summer activity and winter downregulation in evergreens is difficult since this is a largely invisible process, unlike in deciduous trees that have a visible budding and a sequence of leaf unfolding in the spring and leaf abscission in the fall. The light-use efficiency (LUE) model estimates gross primary productivity (GPP) and may be parameterized using remotely sensed vegetation indices. Using spectral reflectance data, we derived the normalized difference vegetation index (NDVI), a measure of leaf "greenness", and the photochemical reflectance index (PRI), a proxy for chlorophyll:carotenoid ratios which is related to photosynthetic activity. To better understand the relationship between these vegetation indices and photosynthetic activity and to contrast this relationship between plant functional types, the phenology of NDVI, PRI and photosynthesis was monitored in an evergreen forest and a mixed deciduous forest at the leaf and canopy scale. Our data indicates that the LUE model can be parameterized by NDVI and PRI to track forest phenology. Differences in the sensitivity of PRI and NDVI will be discussed. These findings have implications to address the phenology of evergreen conifers by using PRI to complement NDVI in the LUE model, potentially improving model productivity estimates in northern hemisphere forests, that are dominated by conifers.

137Cs vertical migration in a deciduous forest soil following the Fukushima Dai-ichi Nuclear Power Plant accident

International Nuclear Information System (INIS)

Nakanishi, Takahiro; Matsunaga, Takeshi; Koarashi, Jun; Atarashi-Andoh, Mariko

2014-01-01

The large amount of 137 Cs deposited on the forest floor because of the Fukushima Dai-ichi Nuclear Power Plant accident represents a major potential long-term source for mobile 137 Cs. To investigate 137 Cs mobility in forest soils, we investigated the vertical migration of 137 Cs through seepage water, using a lysimetric method. The study was conducted in a deciduous forest soil over a period spanning 2 month to 2 y after the Fukushima nuclear accident. Our observations demonstrated that the major part of 137 Cs in the litter layer moved into the mineral soil within one year after the accident. On the other hand, the topsoil prevented migration of 137 Cs, and only 2% of 137 Cs in the leachate from litter and humus layer penetrated below a 10 cm depth. The annual migration below a 10 cm depth accounted for 0.1% of the total 137 Cs inventory. Therefore, the migration of 137 Cs by seepage water comprised only a very small part of the total 137 Cs inventory in the mineral soil, which was undetectable from the vertical distribution of 137 Cs in the soil profile. In the present and immediate future, most of the 137 Cs deposited on the forest floor will probably remain in the topsoil successively, although a small but certain amount of bioavailable 137 Cs exists in forest surface soil. -- Highlights: • Lysimeter captured 137 Cs mobility in a forest soil after the Fukushima accident. • Major part of 137 Cs in the litter layer moved into the mineral soil within a year. • Litter-leachate 137 Cs was predominantly adsorbed within the topsoil. • The annual migration below a 10 cm depth was 0.1% of the total 137 Cs inventory

A comparison of {sup 137}Cs radioactivity in localized evergreen and deciduous plant species

Energy Technology Data Exchange (ETDEWEB)

Rangel, R.C.

1996-05-01

A vegetation study at the Comanche Peak Steam Electric Station (CPSES) near Glen Rose, Texas was conducted in 1991 and 1992. The CPSES is a commercial nuclear power plant owned and operated by Texas Utilities Electric of Dallas, Texas. The US Nuclear Regulatory Commission (USNRC) requires the CPSES to routinely sample broadleaf vegetation in place of milk samples. Few commercial dairies exist in the vicinity. Broadleaf tree species are scarce because the climate and local limestone geology have produced a dry rolling hill topography. An evergreen juniper is the dominant tree species. Few broadleaves during the winter season have hindered year-round sampling. This study compares the environmental {sup 137}Cs concentrations between broadleaf and evergreen foliage at CPSES. Soil {sup 137}Cs concentrations from each vegetation location were also compared to the foliage {sup 137}Cs concentrations. The study`s objective was to determine if the deciduous and evergreen vegetation {sup 137}Cs concentrations are statistically the same.

Ecophysiological Remote Sensing of Leaf-Canopy Photosynthetic Characteristics in a Cool-Temperate Deciduous Forest in Japan

Science.gov (United States)

Noda, H. M.; Muraoka, H.

2014-12-01

Satellite remote sensing of structure and function of canopy is crucial to detect temporal and spatial distributions of forest ecosystems dynamics in changing environments. The spectral reflectance of the canopy is determined by optical properties (spectral reflectance and transmittance) of single leaves and their spatial arrangements in the canopy. The optical properties of leaves reflect their pigments contents and anatomical structures. Thus detailed information and understandings of the consequence between ecophysiological traits and optical properties from single leaf to canopy level are essential for remote sensing of canopy ecophysiology. To develop the ecophysiological remote sensing of forest canopy, we have been promoting multiple and cross-scale measurements in "Takayama site" belonging to AsiaFlux and JaLTER networks, located in a cool-temperate deciduous broadleaf forest on a mountainous landscape in Japan. In this forest, in situ measurement of canopy spectral reflectance has been conducted continuously by a spectroradiometer as part of the "Phenological Eyes Network (PEN)" since 2004. To analyze the canopy spectral reflectance from leaf ecophysiological viewpoints, leaf mass per area, nitrogen content, chlorophyll contents, photosynthetic capacities and the optical properties have been measured for dominant canopy tree species Quercus crispla and Betula ermanii throughout the seasons for multiple years.Photosynthetic capacity was largely correlated with chlorophyll contents throughout the growing season in both Q. crispla and B. ermanii. In these leaves, the reflectance at "red edge" (710 nm) changed by corresponding to the changes of chlorophyll contents throughout the seasons. Our canopy-level examination showed that vegetation indices obtained by red edge reflectance have linear relationship with leaf chlorophyll contents and photosynthetic capacity. Finally we apply this knowledge to the Rapid Eye satellite imagery around Takayama site to scale

Are Boreal Ovenbirds, Seiurus aurocapilla, More Prone to Move across Inhospitable Landscapes in Alberta's Boreal Mixedwood Forest than in Southern Québec's Temperate Deciduous Forest?

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Marc Bélisle

2007-12-01

Full Text Available Population life-history traits such as the propensity to move across inhospitable landscapes should be shaped by exposure to landscape structure over evolutionary time. Thus, birds that recently evolved in landscapes fragmented by natural disturbances such as fire would be expected to show greater behavioral and morphological vagility relative to conspecifics that evolved under less patchy landscapes shaped by fewer and finer-scaled disturbances, i.e., the resilience hypothesis. These predictions are not new, but they remain largely untested, even for well-studied taxa such as neotropical migrant birds. We combined two experimental translocation, i.e., homing, studies to test whether Ovenbird, Seiurus aurocapilla, from the historically dynamic boreal mixedwood forest of north-central Alberta (n = 55 is more vagile than Ovenbird from historically less dynamic deciduous forest of southern Québec (n = 89. We found no regional difference in either wing loading or the response of homing Ovenbird to landscape structure. Nevertheless, this study presents a heuristic framework that can advance the understanding of boreal landscape dynamics as an evolutionary force.

Genetic structure and breeding system of a rare understory herb, Dysosma versipellis (Berberidaceae), from temperate deciduous forests in China.

Science.gov (United States)

Guan, Bi-Cai; Fu, Cheng-Xing; Qiu, Ying-Xiong; Zhou, Shi-Liang; Comes, Hans Peter

2010-01-01

To evaluate the role of Quaternary refugial isolation in allopatric (incipient) speciation of East Asian temperate forest biotas, we analyzed amplified fragment length polymorphisms (AFLPs) and the breeding system in Dysosma versipellis. The study revealed that D. versipellis is mostly self-incompatible, genetically highly subdivided and depauperate at the population level (e.g., Φ(ST) = 0.572/H(E) = 0.083), and characterized by a low pollen-to-seed migration ratio (r ≈ 4.0). The latter outcome likely reflects limited pollen flow in a low-seed disperser whose hypothesized "sapromyophilous" flowers undergo scarce, inefficient, and likely specialized cross-pollination by small Anoplodera beetles, rather than carrion flies as assumed previously. In consequence, fruit set in D. versipellis was strongly pollen-limited. Our AFLP data support the hypothesis of a long-standing cessation of gene flow between western and central eastern populations, consistent with previous chloroplast DNA data. This phylogeographic pattern supports the role of the Sichuan Basin as a floristic boundary separating the Sino-Himalayan vs. Sino-Japanese Forest subkingdoms. Our genetic data of D. versipellis also imply that temperate deciduous forest elements to the west and the east of this basin responded differently to Quaternary climate change, which may have triggered or is leading to allopatric (incipient) speciation.

Seasonal ozone uptake by a warm-temperate mixed deciduous and evergreen broadleaf forest in western Japan estimated by the Penman–Monteith approach combined with a photosynthesis-dependent stomatal model

International Nuclear Information System (INIS)

Kitao, Mitsutoshi; Komatsu, Masabumi; Hoshika, Yasutomo; Yazaki, Kenichi; Yoshimura, Kenichi; Fujii, Saori; Miyama, Takafumi; Kominami, Yuji

2014-01-01

Canopy-level stomatal conductance over a warm-temperate mixed deciduous and evergreen broadleaf forest in Japan was estimated by the Penman–Monteith approach, as compensated by a semi-empirical photosynthesis-dependent stomatal model, where photosynthesis, relative humidity, and CO 2 concentration were assumed to regulate stomatal conductance. This approach, using eddy covariance data and routine meteorological observations at a flux tower site, permits the continuous estimation of canopy-level O 3 uptake, even when the Penman–Monteith approach is unavailable (i.e. in case of direct evaporation from soil or wet leaves). Distortion was observed between the AOT40 exposure index and O 3 uptake through stomata, as AOT40 peaked in April, but with O 3 uptake occurring in July. Thus, leaf pre-maturation in the predominant deciduous broadleaf tree species (Quercus serrata) might suppress O 3 uptake in springtime, even when the highest O 3 concentrations were observed. -- Highlights: • We estimate canopy-level O 3 uptake in a warm-temperate mixed forest in Japan. • The Penman–Monteith approach is compensated by a photosynthesis-dependent model. • Stomatal conductance can be estimated, even in a partly-opened or wet canopy. • The estimated O 3 dose peaks in summer though O 3 exposure peaks in spring. -- Estimation of seasonal O 3 uptake over a mixed-temperate forest compensated by a photosynthesis-dependent stomatal model

Estimating carbon emissions from forest fires during 1980 to 1999 in ...

African Journals Online (AJOL)

white birch (Betula platyphylla Suk.), mixed broadleaved-conifer (L. gmelinii & B. platyphylla) and Mongolian oak (Quercus mongolica Fish.) forests were 437 947, 20 939, 142 527, 168 532 and 1 375 hm2 during 1980 to 1999 period, respectively. The fuel consumed based on these forests were 29.0 to 46.5, 16.7 to 26.5, ...

Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients.

Science.gov (United States)

Fajardo, Alex; Piper, Frida I; Hoch, Günter

2013-08-01

The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous-evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations. Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous-evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra). Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P treeline species are sink limited when faced with decreasing temperatures. Despite the overall higher requirements of deciduous tree species for carbon storage, no indication was found of carbon limitation in deciduous species in the alpine treeline ecotone.

Modeling biophysical properties of broad-leaved stands in the hyrcanian forests of Iran using fused airborne laser scanner data and ultraCam-D images

Science.gov (United States)

Mohammadi, Jahangir; Shataee, Shaban; Namiranian, Manochehr; Næsset, Erik

2017-09-01

Inventories of mixed broad-leaved forests of Iran mainly rely on terrestrial measurements. Due to rapid changes and disturbances and great complexity of the silvicultural systems of these multilayer forests, frequent repetition of conventional ground-based plot surveys is often cost prohibitive. Airborne laser scanning (ALS) and multispectral data offer an alternative or supplement to conventional inventories in the Hyrcanian forests of Iran. In this study, the capability of a combination of ALS and UltraCam-D data to model stand volume, tree density, and basal area using random forest (RF) algorithm was evaluated. Systematic sampling was applied to collect field plot data on a 150 m × 200 m sampling grid within a 1100 ha study area located at 36°38‧- 36°42‧N and 54°24‧-54°25‧E. A total of 308 circular plots (0.1 ha) were measured for calculation of stand volume, tree density, and basal area per hectare. For each plot, a set of variables was extracted from both ALS and multispectral data. The RF algorithm was used for modeling of the biophysical properties using ALS and UltraCam-D data separately and combined. The results showed that combining the ALS data and UltraCam-D images provided a slight increase in prediction accuracy compared to separate modeling. The RMSE as percentage of the mean, the mean difference between observed and predicted values, and standard deviation of the differences using a combination of ALS data and UltraCam-D images in an independent validation at 0.1-ha plot level were 31.7%, 1.1%, and 84 m3 ha-1 for stand volume; 27.2%, 0.86%, and 6.5 m2 ha-1 for basal area, and 35.8%, -4.6%, and 77.9 n ha-1 for tree density, respectively. Based on the results, we conclude that fusion of ALS and UltraCam-D data may be useful for modeling of stand volume, basal area, and tree density and thus gain insights into structural characteristics in the complex Hyrcanian forests.

Long-term changes in soil pH across major forest ecosystems in China

Science.gov (United States)

Yang, Yuanhe; Li, Pin; He, Honglin; Zhao, Xia; Datta, Arindam; Ma, Wenhong; Zhang, Ying; Liu, Xuejun; Han, Wenxuan; Wilson, Maxwell C.; Fang, Jingyun

2015-02-01

Atmospheric acidic deposition has been a major environmental problem since the industrial revolution. However, our understanding of the effect of acidic deposition on soil pH is inconclusive. Here we examined temporal variations in topsoil pH and their relationships with atmospheric sulfur and nitrogen deposition across China's forests from the 1980s to the 2000s. To accomplish this goal, we conducted artificial neural network simulations using historical soil inventory data from the 1980s and a data set synthesized from literature published after 2000. Our results indicated that significant decreases in soil pH occurred in broadleaved forests, while minor changes were observed in coniferous and mixed coniferous and broadleaved forests. The magnitude of soil pH change was negatively correlated with atmospheric sulfur and nitrogen deposition. This relationship highlights the need for stringent measures that reduce sulfur and nitrogen emissions so as to maintain ecosystem structure and function.

OZONE AND SULFUR DIOXIDE DRY DEPOSITION TO FORESTS: OBSERVATIONS AND MODEL EVALUATION

Science.gov (United States)

Fluxes and deposition velocities of O3 and SO2 were measured over both a deciduous and a mixed coniferous-deciduous forest for full growing seasons. Fluxes and deposition velocities of O3 were measured over a coniferous forest for a month. Mean deposition velocities of 0.35 t...

Public Preferences Across Europe for Different Forest Stand Types as Sites for Recreation

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David M. Edwards

2012-03-01

Full Text Available A Delphi survey involving experts in forest preference research was carried out to derive scores for the recreational value of 240 forest stand types across Europe. The survey was organized around four regional panels: Great Britain, Nordic Region, Central Europe, and Iberia. In each region, 60 forest stand types were defined according to five forest management alternatives (FMAs on a continuum of management intensity, four phases of development (establishment, young, medium, and adult, and three tree species types (conifer, broadleaved, and mixed stands of conifer and broadleaved. The resulting scores were examined using conjoint analysis to determine the relative importance of the three structural attributes (FMA, phase of development, and tree species type, and each level or component of the attributes. The findings quantify the extent to which forest visitors prefer a degree of management to unmanaged forest nature reserves across the four regions. Phase of development was shown to make the highest contribution to the recreational value of forests while the contribution of tree species type was shown to be relatively unimportant. While the results are indicative, they provide evidence to support long-term retention and low-impact silviculture in forests where recreation is a primary objective of management.

Estimating leaf area and leaf biomass of open-grown deciduous urban trees

Science.gov (United States)

David J. Nowak

1996-01-01

Logarithmic regression equations were developed to predict leaf area and leaf biomass for open-grown deciduous urban trees based on stem diameter and crown parameters. Equations based on crown parameters produced more reliable estimates. The equations can be used to help quantify forest structure and functions, particularly in urbanizing and urban/suburban areas.

A metagenomics-based approach to the top-down effect on the detritivore food web: a salamanders influence on fungal communities within a deciduous forest.

Science.gov (United States)

Walker, Donald M; Lawrence, Brandy R; Esterline, Dakota; Graham, Sean P; Edelbrock, Michael A; Wooten, Jessica A

2014-11-01

The flow of energy within an ecosystem can be considered either top-down, where predators influence consumers, or bottom-up, where producers influence consumers. Plethodon cinereus (Red-backed Salamander) is a terrestrial keystone predator who feeds on invertebrates within the ecosystem. We investigated the impact of the removal of P. cinereus on the detritivore food web in an upland deciduous forest in northwest Ohio, U.S.A. A total of eight aluminum enclosures, each containing a single P. cinereus under a small log, were constructed in the deciduous forest. On Day 1 of the experiment, four salamanders were evicted from four of the eight enclosures. Organic matter and soil were collected from the center of each enclosure at Day 1 and Day 21. From each sample, DNA was extracted, fungal-specific amplification performed, and 454 pyrosequencing was used to sequence the nuclear ribosomal internal transcribed spacer (ITS2) region and partial ribosomal large subunit (LSU). Changes in overall fungal community composition or species diversity were not statistically significant between treatments. Statistically significant shifts in the most abundant taxonomic groups of fungi were documented in presence but not absence enclosures. We concluded that P. cinereus does not affect the overall composition or diversity of fungal communities, but does have an impact on specific groups of fungi. This study used a metagenomics-based approach to investigate a missing link among a keystone predator, P. cinereus, invertebrates, and fungal communities, all of which are critical in the detritivore food web.

Edge Effects on Community and Social Structure of Northern Temperate Deciduous Forest Ants

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Valerie S. Banschbach

2012-01-01

Full Text Available Determining how ant communities are impacted by challenges from habitat fragmentation, such as edge effects, will help us understand how ants may be used as a bioindicator taxon. To assess the impacts of edge effects upon the ant community in a northern temperate deciduous forest, we studied edge and interior sites in Jericho, VT, USA. The edges we focused upon were created by recreational trails. We censused the ants at these sites for two consecutive growing seasons using pitfall traps and litter plot excavations. We also collected nests of the most common ant species at our study sites, Aphaenogaster rudis, for study of colony demography. Significantly greater total numbers of ants and ant nests were found in the edge sites compared to the interior sites but rarefaction analysis showed no significant difference in species richness. Aphaenogaster rudis was the numerically dominant ant in the habitats sampled but had a greater relative abundance in the interior sites than in the edge sites both in pitfall and litter plot data. Queen number of A. rudis significantly differed between the nests collected in the edge versus the interior sites. Habitat-dependent changes in social structure of ants represent another possible indicator of ecosystem health.

Effects of climate variability and functional changes on carbon cycling in a temperate deciduous forest

Energy Technology Data Exchange (ETDEWEB)

Wu, Jian

2013-03-15

Temperate forests are globally important carbon (C) stocks and sinks. A decadal (1997-2009) trend of increasing C uptake has been observed in an intensively studied temperate deciduous forest, Soroe (Zealand, Denmark). This gave the impetus to investigate the factors controlling the C cycling and the fundamental processes at work in this type of ecosystem. The major objectives of this study were to (1) evaluate to what extent and at what temporal scales, direct climatic variability and functional changes (e.g. changes in the structure or physiological properties) regulate the interannual variability (IAV) in the ecosystem C balance; (2) provide a synthesis of the ecosystem C budget at this site and (3) investigate whether terrestrial ecosystem models can dynamically simulate the trend of increasing C uptake. Data driven analysis, semi-empirical and process-based modelling experiments were performed in a series of studies in order to provide a complete assessment of the carbon storage and allocation within the ecosystem and clarify the mechanisms responsible for the observed variability and trend in the ecosystem C fluxes. Combining all independently estimated ecosystem carbon budget (ECB) datasets and other calculated ECB components based on mass balance equations, a synthesis of the carbon cycling was performed. The results showed that this temperature deciduous forest was moderately productive with both high rates of gross primary production and ecosystem respiration. Approximately 62% of the gross assimilated carbon was respired by the living plants, while 21% was contributed to the soil as litter production, the latter balancing the total heterotrophic respiration. The remaining 17% was either stored in the plants (mainly as aboveground biomass) or removed from the system as wood production. In general, the ECB component datasets were consistent after the cross-checking. This, together with their characterized uncertainties, can be used in model data fusion

Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

Science.gov (United States)

M. Mazur; C.P.J. Mitchell; C.S. Eckley; S.L. Eggert; R.K. Kolka; S.D. Sebestyen; E.B. Swain

2014-01-01

Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown.We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg...

Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests

DEFF Research Database (Denmark)

Augusto, Laurent; De Schrijver, An; Vesterdal, Lars

2015-01-01

It has been recognized for a long time that the overstorey composition of a forest partly determines its biological and physical-chemical functioning. Here, we review evidence of the influence of evergreen gymnosperm (EG) tree species and deciduous angiosperm (DA) tree species on the water balance...... present the current state of the art, define knowledge gaps, and briefly discuss how selection of tree species can be used to mitigate pollution or enhance accumulation of stable organic carbon in the soil. The presence of EGs generally induces a lower rate of precipitation input into the soil than DAs......, resulting in drier soil conditions and lower water discharge. Soil temperature is generally not different, or slightly lower, under an EG canopy compared to a DA canopy. Chemical properties, such as soil pH, can also be significantly modified by taxonomic groups of tree species. Biomass production...

CARBON SEQUESTRATION IN PASTURES WITH TREES, TREELESS PASTURES AND DECIDUOUS FOREST FROM HUATUSCO, VERACRUZ

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José Antonio Torres-Rivera

2011-11-01

Full Text Available It was compared the amount of carbon (C sequestered in a pasture with trees (P+Ar and in conventional treeless pastures (P and deciduous forest (BC, typical of the region of Huatusco, Veracruz, Mexico. Total C sequestered by the systems evaluated was 49.9, 63.0 and 469.8 ton ha-1 for P, P+Ar and BC, respectively. The system with the highest amount of C sequestered was BC, with almost equal proportions in the aerial (268.4 ton ha-1 and belowground parts (201.4 ton ha-1. The amount of C sequestered in the livestock systems represented about one tenth of that sequestered in BC, being higher the proportion obtained in P+Ar (13.4 % compared to P (10.6 %. In both livestock systems, a significantly greater amount of C was sequestered in the soil organic matter than in the aerial biomass, with 59.7 and 3.29 ton ha-1 in P+Ar, and with 48.2 and 1.78 ton ha-1 in P, respectively. It is expected that as trees of the P+Ar system gain volume, C sequestration will increase, especially in the aerial biomass.

Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan. Topical report, October 1990--August 1992

Energy Technology Data Exchange (ETDEWEB)

Rastorfer, J.R. [Chicago State Univ., IL (United States). Dept. of Biological Sciences; Van Dyke, G.D.; Zellmer, S.D.; Wilkey, P.L. [Argonne National Lab., IL (United States)

1995-04-01

This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth wetland sites mapped Lenawee soils were selected in Midland County, Michigan: Site 1, a younger stand subjected to recent selective logging, and Site 2, a more mature stand. The collection of ecological data to analyze plant succession on the right-of-way (ROW) and the effects of the developing ROW plant communities on adjacent forest communities was initiated in 1989. Cover class estimates were made for understory and ROW plant species on the basis of 1 {times} 1{minus}m quadrats. Individual stem diameters and species counts were recorded for overstory plants in 10{minus}m quadrats. Although long-term studies have not been completed, firm baseline data were established for comparative analyses with future sampling. Current data indicate that vegetation became well-established on the ROW within one year and subsequently increased in coverage. About 65% of the species were wetland indicators, and the dominants included seeded and natural invading species; nevertheless, some elements of the original flora regenerated and persist. The plants of the ecotone understories of both sites changed from their original composition as a result of the installation of the gas pipeline. Although some forest species persist at both sites, the ecotone of Site I was influenced more by the seeded species, whereas the natural invaders were more important at Site 2.

Long-term effects of climate change on carbon storage and tree species composition in a dry deciduous forest.

Science.gov (United States)

Fekete, István; Lajtha, Kate; Kotroczó, Zsolt; Várbíró, Gábor; Varga, Csaba; Tóth, János Attila; Demeter, Ibolya; Veperdi, Gábor; Berki, Imre

2017-08-01

Forest vegetation and soils have been suggested as potentially important sinks for carbon (C) with appropriate management and thus are implicated as effective tools in stabilizing climate even with increasing anthropogenic release of CO 2 . Drought, however, which is often predicted to increase in models of future climate change, may limit net primary productio (NPP) of dry forest types, with unknown effects on soil C storage. We studied C dynamics of a deciduous temperate forest of Hungary that has been subject to significant decreases in precipitation and increases in temperature in recent decades. We resampled plots that were established in 1972 and repeated the full C inventory by analyzing more than 4 decades of data on the number of living trees, biomass of trees and shrubs, and soil C content. Our analyses show that the decline in number and biomass of oaks started around the end of the 1970s with a 71% reduction in the number of sessile oak stems by 2014. Projected growth in this forest, based on the yield table's data for Hungary, was 4.6 kg C/m 2 . Although new species emerged, this new growth and small increases in oak biomass resulted in only 1.9 kg C/m 2 increase over 41 years. The death of oaks increased inputs of coarse woody debris to the surface of the soil, much of which is still identifiable, and caused an increase of 15.5%, or 2.6 kg C/m 2 , in the top 1 m of soil. Stability of this fresh organic matter input to surface soil is unknown, but is likely to be low based on the results of a colocated woody litter decomposition study. The effects of a warmer and drier climate on the C balance of forests in this region will be felt for decades to come as woody litter inputs decay, and forest growth remains impeded. © 2017 John Wiley & Sons Ltd.

Increased topsoil carbon stock across China's forests.

Science.gov (United States)

Yang, Yuanhe; Li, Pin; Ding, Jinzhi; Zhao, Xia; Ma, Wenhong; Ji, Chengjun; Fang, Jingyun

2014-08-01

Biomass carbon accumulation in forest ecosystems is a widespread phenomenon at both regional and global scales. However, as coupled carbon-climate models predicted, a positive feedback could be triggered if accelerated soil carbon decomposition offsets enhanced vegetation growth under a warming climate. It is thus crucial to reveal whether and how soil carbon stock in forest ecosystems has changed over recent decades. However, large-scale changes in soil carbon stock across forest ecosystems have not yet been carefully examined at both regional and global scales, which have been widely perceived as a big bottleneck in untangling carbon-climate feedback. Using newly developed database and sophisticated data mining approach, here we evaluated temporal changes in topsoil carbon stock across major forest ecosystem in China and analysed potential drivers in soil carbon dynamics over broad geographical scale. Our results indicated that topsoil carbon stock increased significantly within all of five major forest types during the period of 1980s-2000s, with an overall rate of 20.0 g C m(-2) yr(-1) (95% confidence interval, 14.1-25.5). The magnitude of soil carbon accumulation across coniferous forests and coniferous/broadleaved mixed forests exhibited meaningful increases with both mean annual temperature and precipitation. Moreover, soil carbon dynamics across these forest ecosystems were positively associated with clay content, with a larger amount of SOC accumulation occurring in fine-textured soils. In contrast, changes in soil carbon stock across broadleaved forests were insensitive to either climatic or edaphic variables. Overall, these results suggest that soil carbon accumulation does not counteract vegetation carbon sequestration across China's forest ecosystems. The combination of soil carbon accumulation and vegetation carbon sequestration triggers a negative feedback to climate warming, rather than a positive feedback predicted by coupled carbon-climate models

Climate- and successional-related changes in functional composition of European forests are strongly driven by tree mortality.

Science.gov (United States)

Ruiz-Benito, Paloma; Ratcliffe, Sophia; Zavala, Miguel A; Martínez-Vilalta, Jordi; Vilà-Cabrera, Albert; Lloret, Francisco; Madrigal-González, Jaime; Wirth, Christian; Greenwood, Sarah; Kändler, Gerald; Lehtonen, Aleksi; Kattge, Jens; Dahlgren, Jonas; Jump, Alistair S

2017-10-01

Intense droughts combined with increased temperatures are one of the major threats to forest persistence in the 21st century. Despite the direct impact of climate change on forest growth and shifts in species abundance, the effect of altered demography on changes in the composition of functional traits is not well known. We sought to (1) quantify the recent changes in functional composition of European forests; (2) identify the relative importance of climate change, mean climate and forest development for changes in functional composition; and (3) analyse the roles of tree mortality and growth underlying any functional changes in different forest types. We quantified changes in functional composition from the 1980s to the 2000s across Europe by two dimensions of functional trait variation: the first dimension was mainly related to changes in leaf mass per area and wood density (partially related to the trait differences between angiosperms and gymnosperms), and the second dimension was related to changes in maximum tree height. Our results indicate that climate change and mean climatic effects strongly interacted with forest development and it was not possible to completely disentangle their effects. Where recent climate change was not too extreme, the patterns of functional change generally followed the expected patterns under secondary succession (e.g. towards late-successional short-statured hardwoods in Mediterranean forests and taller gymnosperms in boreal forests) and latitudinal gradients (e.g. larger proportion of gymnosperm-like strategies at low water availability in forests formerly dominated by broad-leaved deciduous species). Recent climate change generally favoured the dominance of angiosperm-like related traits under increased temperature and intense droughts. Our results show functional composition changes over relatively short time scales in European forests. These changes are largely determined by tree mortality, which should be further

The Forest Fire Problem of Degrading Tain II Forest Reserve in Ghana

African Journals Online (AJOL)

Agribotix GCS 068

2010-01-11

Jan 11, 2010 ... informal practice was done before the 1982/83 dry season when the country ..... Tain II Forest Reserve forms part of the Dry Semi-Deciduous Fire ...... 2003/08; Forest Resources Development Service Working Paper FFM/2. .... Environment, Resources and Development Thailand. web.idrc.ca/uploads/user-.

Forest influences on snow accumulation and snowmelt at the Hubbard Brook Experimental Forest, New Hampshire, USA

Science.gov (United States)

Colin A. Penn; Beverley C. Wemple; John L. Campbell

2012-01-01

Many factors influence snow depth, water content and duration in forest ecosystems. The effects of forest cover and canopy gap geometry on snow accumulation has been well documented in coniferous forests of western North America and other regions; however, few studies have evaluated these effects on snowpack dynamics in mixed deciduous forests of the northeastern USA....

Acidotolerant Bacteria and Fungi as a Sink of Methanol-Derived Carbon in a Deciduous Forest Soil

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Mareen Morawe

2017-07-01

Full Text Available Methanol is an abundant atmospheric volatile organic compound that is released from both living and decaying plant material. In forest and other aerated soils, methanol can be consumed by methanol-utilizing microorganisms that constitute a known terrestrial sink. However, the environmental factors that drive the biodiversity of such methanol-utilizers have been hardly resolved. Soil-derived isolates of methanol-utilizers can also often assimilate multicarbon compounds as alternative substrates. Here, we conducted a comparative DNA stable isotope probing experiment under methylotrophic (only [13C1]-methanol was supplemented and combined substrate conditions ([12C1]-methanol and alternative multi-carbon [13Cu]-substrates were simultaneously supplemented to (i identify methanol-utilizing microorganisms of a deciduous forest soil (European beech dominated temperate forest in Germany, (ii assess their substrate range in the soil environment, and (iii evaluate their trophic links to other soil microorganisms. The applied multi-carbon substrates represented typical intermediates of organic matter degradation, such as acetate, plant-derived sugars (xylose and glucose, and a lignin-derived aromatic compound (vanillic acid. An experimentally induced pH shift was associated with substantial changes of the diversity of active methanol-utilizers suggesting that soil pH was a niche-defining factor of these microorganisms. The main bacterial methanol-utilizers were members of the Beijerinckiaceae (Bacteria that played a central role in a detected methanol-based food web. A clear preference for methanol or multi-carbon substrates as carbon source of different Beijerinckiaceae-affiliated phylotypes was observed suggesting a restricted substrate range of the methylotrophic representatives. Apart from Bacteria, we also identified the yeasts Cryptococcus and Trichosporon as methanol-derived carbon-utilizing fungi suggesting that further research is needed to

Association of extinction risk of saproxylic beetles with ecological degradation of forests in Europe.

Science.gov (United States)

Seibold, Sebastian; Brandl, Roland; Buse, Jörn; Hothorn, Torsten; Schmidl, Jürgen; Thorn, Simon; Müller, Jörg

2015-04-01

To reduce future loss of biodiversity and to allocate conservation funds effectively, the major drivers behind large-scale extinction processes must be identified. A promising approach is to link the red-list status of species and specific traits that connect species of functionally important taxa or guilds to resources they rely on. Such traits can be used to detect the influence of anthropogenic ecosystem changes and conservation efforts on species, which allows for practical recommendations for conservation. We modeled the German Red List categories as an ordinal index of extinction risk of 1025 saproxylic beetles with a proportional-odds linear mixed-effects model for ordered categorical responses. In this model, we estimated fixed effects for intrinsic traits characterizing species biology, required resources, and distribution with phylogenetically correlated random intercepts. The model also allowed predictions of extinction risk for species with no red-list category. Our model revealed a higher extinction risk for lowland and large species as well as for species that rely on wood of large diameter, broad-leaved trees, or open canopy. These results mirror well the ecological degradation of European forests over the last centuries caused by modern forestry, that is the conversion of natural broad-leaved forests to dense conifer-dominated forests and the loss of old growth and dead wood. Therefore, conservation activities aimed at saproxylic beetles in all types of forests in Central and Western Europe should focus on lowlands, and habitat management of forest stands should aim at increasing the amount of dead wood of large diameter, dead wood of broad-leaved trees, and dead wood in sunny areas. © 2014 Society for Conservation Biology.

FITOSSOCIOLOGIA DE FRAGMENTOS DE FLORESTA ESTACIONAL DECIDUAL NO ESTADO DE SANTA CATARINA – BRASIL

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Lauri Amândio Schorn

2014-01-01

Full Text Available This study aimed to evaluate the species composition and structure of Seasonal Deciduous Forest in the southern Brazilian state of Santa Catarina, including the tree/shrub component and the natural regeneration. We also compared the floristic composition between the components and discussed about the conservation condition of forests. The study was based on sample plots established by the Floristic and Forest Inventory of Santa Catarina state. Tree/shrub component was sampled by 78 plots placed systematically with 4,000 m² of sample area each, were individuals with DBH (diameter at breast height ≥ 10 cm was measured. Regeneration (DBH 1.50 m was sampled in subplots of 100 m² each. Structure and diversity of sample plots were analyzed in both components; species were classified by their ecologic group. To test the association between components was made a Non-metric Multidimensional Scaling (NMSD and Mantel test. We sampled 245 species, among them 215 in the tree/shrub component (79 of them exclusive, 165 species in the natural regeneration (30 exclusive ones and 136 species common to the two components. The association between components was confirmed with NMSD and Mantel test (r = 0.34; p = 0.001. Species with major importance value were mostly early secondary species that emphasizes the consequences of long term exploitation and degradation of Seasonal Deciduous Forest in Santa Catarina.

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

Science.gov (United States)

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

2018-01-01

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

Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic forest.

Science.gov (United States)

Melo, Geruza L; Miotto, Barbara; Peres, Brisa; Cáceres, Nilton C

2013-01-01

Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.

Long-term litter manipulation alters soil organic matter turnover in a temperate deciduous forest.

Science.gov (United States)

Wang, Jun-Jian; Pisani, Oliva; Lin, Lisa H; Lun, Olivia O Y; Bowden, Richard D; Lajtha, Kate; Simpson, André J; Simpson, Myrna J

2017-12-31

Understanding soil organic matter (OM) biogeochemistry at the molecular-level is essential for assessing potential impacts from management practices and climate change on shifts in soil carbon storage. Biomarker analyses and nuclear magnetic resonance (NMR) spectroscopy were used in an ongoing detrital input and removal treatment experiment in a temperate deciduous forest in Pennsylvania, USA, to examine how above- and below-ground plant inputs control soil OM quantity and quality at the molecular-level. From plant material to surface soils, the free acyclic lipids and cutin, suberin, and lignin biomarkers were preferentially retained over free sugars and free cyclic lipids. After 20years of above-ground litter addition (Double Litter) or exclusion (No Litter) treatments, soil OM composition was relatively more degraded, as revealed by solid-state 13 C NMR spectroscopy. Under Doubled Litter inputs, soil carbon and phospholipid fatty acid (PLFA) concentrations were unchanged, suggesting that the current OM degradation status is a reflection of microbial-mediated degradation that occurred prior to the 20-year sampling campaign. Soil OM degradation was higher in the No Litter treatments, likely due to the decline in fresh, above-ground litter inputs over time. Furthermore, root and root and litter exclusion treatments (No Roots and No Inputs, respectively) both significantly reduced free sugars and PLFAs and increased preservation of suberin-derived compounds. PLFA stress ratios and the low N-acetyl resonances from diffusion edited 1 H NMR also indicate substrate limitations and reduced microbial biomass with these treatments. Overall, we highlight that storage of soil carbon and its biochemical composition do not linearly increase with plant inputs because the microbial processing of soil OM is also likely altered in the studied forest. Copyright © 2017 Elsevier B.V. All rights reserved.

Do evergreen and deciduous trees have different effects on net N mineralization in soil?

Science.gov (United States)

Mueller, Kevin E; Hobbie, Sarah E; Oleksyn, Jacek; Reich, Peter B; Eissenstat, David M

2012-06-01

Evergreen and deciduous plants are widely expected to have different impacts on soil nitrogen (N) availability because of differences in leaf litter chemistry and ensuing effects on net N mineralization (N(min)). We evaluated this hypothesis by compiling published data on net N(min) rates beneath co-occurring stands of evergreen and deciduous trees. The compiled data included 35 sets of co-occurring stands in temperate and boreal forests. Evergreen and deciduous stands did not have consistently divergent effects on net N(min) rates; net N(min) beneath deciduous trees was higher when comparing natural stands (19 contrasts), but equivalent to evergreens in plantations (16 contrasts). We also compared net N(min) rates beneath pairs of co-occurring genera. Most pairs of genera did not differ consistently, i.e., tree species from one genus had higher net N(min) at some sites and lower net N(min) at other sites. Moreover, several common deciduous genera (Acer, Betula, Populus) and deciduous Quercus spp. did not typically have higher net N(min) rates than common evergreen genera (Pinus, Picea). There are several reasons why tree effects on net N(min) are poorly predicted by leaf habit and phylogeny. For example, the amount of N mineralized from decomposing leaves might be less than the amount of N mineralized from organic matter pools that are less affected by leaf litter traits, such as dead roots and soil organic matter. Also, effects of plant traits and plant groups on net N(min) probably depend on site-specific factors such as stand age and soil type.

[Dynamics of total organic carbon (TOC) in hydrological processes in coniferous and broad-leaved mixed forest of Dinghushan].

Science.gov (United States)

Yin, Guangcai; Zhou, Guoyi; Zhang, Deqiang; Wang, Xu; Chu, Guowei; Liu, Yan

2005-09-01

The total flux and concentration of total organic carbon (TOC) in hydrological processes in coniferous and broad-leaved mixed forest of Dinghushan were measured from July 2002 to July 2003. The results showed that the TOC input by precipitation was 41.80 kg x hm(-2) x yr(-1), while its output by surface runoff and groundwater (soil solution at 50 cm depth) was 17.54 and 1.80 kg x hm(-2) x yr(-1), respectively. The difference between input and output was 22.46 kg x hm(-2) x yr(-1), indicating that the ecosystem TOC was in positive balance. The monthly variation of TOC flux in hydrological processes was very similar to that in precipitation. The mean TOC concentration in precipitation was 3.64 mg x L(-1), while that in throughfall and stemflow increased 6.10 and 7.39 times after rain passed through the tree canopies and barks. The mean TOC concentration in surface runoff and in soil solution at 25 and 50 cm depths was 12.72, 7.905 and 3.06 mg x L(-1), respectively. The monthly TOC concentration in throughfall and stemflow had a similar changing tendency, showing an increase at the beginning of growth season (March), a decrease after September, and a little increase in December. The TOC concentration in runoff was much higher during high precipitation months. No obvious monthly variation was observed in soil solution TOC concentration (25 and 50 cm below the surface). Stemflow TOC concentration differed greatly between different tree species. The TOC concentration in precipitation, throughfall, and soil solution (25 and 50 cm depths) decreased with increasing precipitation, and no significant relationship existed between the TOC concentrations in stemflow, surface runoff and precipitation. The TOC concentrations in the hydrological processes fluctuated with precipitation intensity, except for that in stemflow and soil solutions.

Statistical data on forest fund of Russia and changing of forest productivity in the second half of XX century

Science.gov (United States)

Alexeyev V.A.; Markov M.V.; R.A. Birdsey; Birdsey R.A.

2004-01-01

Contains statistical data on area and growing-stock volume of forest lands in Oblasts, Krays and Republics of Russian Federation, for the period 1961-1998. Positive dynamics of average growing stock for coniferous, deciduous hardwood and deciduous softwood tree stands by stand-age groups were disclosed. The impact of main anthropogenic and natural factors, including...

Long and short term changes in the forests of the Cumberland Plateau and Mountains using large scale forest inventory data

Science.gov (United States)

Christopher M. Oswalt; Andrew J. Hartsell

2012-01-01

The Cumberland Plateau and Mountains (CPM) are a significant component of the eastern deciduous forest with biological and cultural resources strongly connected to and dependent upon the forest resources of the region. As a result, continuous inventory and monitoring is critical. The USDA Forest Service Forest Inventory and Analysis (FIA) program has been collecting...

Maximum temperature accounts for annual soil CO2 efflux in temperate forests of Northern China

Science.gov (United States)

Zhou, Zhiyong; Xu, Meili; Kang, Fengfeng; Jianxin Sun, Osbert

2015-01-01

It will help understand the representation legality of soil temperature to explore the correlations of soil respiration with variant properties of soil temperature. Soil temperature at 10 cm depth was hourly logged through twelve months. Basing on the measured soil temperature, soil respiration at different temporal scales were calculated using empirical functions for temperate forests. On monthly scale, soil respiration significantly correlated with maximum, minimum, mean and accumulated effective soil temperatures. Annual soil respiration varied from 409 g C m−2 in coniferous forest to 570 g C m−2 in mixed forest and to 692 g C m−2 in broadleaved forest, and was markedly explained by mean soil temperatures of the warmest day, July and summer, separately. These three soil temperatures reflected the maximum values on diurnal, monthly and annual scales. In accordance with their higher temperatures, summer soil respiration accounted for 51% of annual soil respiration across forest types, and broadleaved forest also had higher soil organic carbon content (SOC) and soil microbial biomass carbon content (SMBC), but a lower contribution of SMBC to SOC. This added proof to the findings that maximum soil temperature may accelerate the transformation of SOC to CO2-C via stimulating activities of soil microorganisms. PMID:26179467

Soil 137Cs activity in a tropical deciduous ecosystem under pasture conversion in Mexico

International Nuclear Information System (INIS)

Garcia-Oliva, F.; Maass, J.M.

1995-01-01

Soil profiles of 137 Cs were measured in a tropical deciduous ecosystem under pasture conversion on the Pacific Coast of Mexico. Soil samples were taken from unperturbed forest, and from pasture plots following forest conversion. The average total 137 Cs areal activity of non-eroded forest sites indicated a base level of 5 315 ± 427 Bq m -2 . On average, total areal activity on hill-tops was significantly higher (range 10-47%) in the forest than in the pastures. A significant correlation was found between the total 137 Cs areal activity and soil organic matter content (r 2 = 0.16). This correlation can be explained by a soil physical-protection hypothesis. The redistribution of 137 Cs in the landscape is explained by soil erosion processes. (author)

[Simulating climate change effect on aboveground carbon sequestration rates of main broadleaved trees in the Xiaoxing'an Mountains area, Northeast China].

Science.gov (United States)

Ma, Jun; Bu, Rencang; Deng, Hua-Wei; Hu, Yuan-Man; Qin, Qin; Han, Feng-Lin

2014-09-01

LANDIS Pro 7.0 model was used to simulate the dynamics of aboveground biomass of ten broadleaved tree species in the Xiao Xing' an Mountains area under current and various climate change scenarios from 2000 to 2200, and carbon content coefficients (CCCs) were coupled to cal- culate the aboveground carbon sequestration rates (ACSRs) of these species. The results showed that in the initial year of simulation, the biomasses and their proportions of Fraxinus mandshurica, Phellodendron amurense, Quercus mongolica, Ulmus propinqua, and Acer mono were relatively low, while those of Betula costata, Betula platyphylla, and Populus davidiana were higher. A trend of rise after decline occurred in ACSR for pioneer species in the mid and late periods of simulation years, but ACSRs for the other broadleaved tree species were considerably complex. The ACSRs of Q. mongolica and Tilla amurensis fluctuated in the ranges of -0.05-0.25 t · hm(-2) · 10 a(-1) and 0.16-1.29 t · hm(-2) · 10 a(-1) in simulation years, respectively. The ACSRs of F. mandshurica, U. propinqua, A. mono, and B. costata showed a trend of decline after rise in late simulation years. There were significant differences in ACSR for P. amurense and B. davurica among various climate change scenarios in the periods of 2050-2100 and 2150-2200, while no significant difference in ACSR for the other species would be detected. Difference of sensitivity of various species in ACSR for future climate scenarios in the Small Khingan Mountains area existed. However, the un- certainty of future climates would not yield significant difference in ACSR for most broadleaved tree species. Moreover, a time lag would exist in the process of climate change effects on temperate forest's ACSR.

Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species

International Nuclear Information System (INIS)

Calder, W.J.; Lifferth, G.; Clair, S.B.S.; Moritz, M.A.

2010-01-01

Smoke from forest fires can persist in the environment for weeks and while there is a substantial amount of literature examining the effects of smoke exposure on seed germination, the effects of smoke on leaf function are nearly un investigated. The objective of this study was to compare growth and primary and secondary metabolic responses of deciduous angiosperm and evergreen conifer tree species to short smoke exposure. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.

Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species

Directory of Open Access Journals (Sweden)

W. John Calder

2010-01-01

Full Text Available Smoke from forest fires can persist in the environment for weeks and while there is a substantial amount of literature examining the effects of smoke exposure on seed germination, the effects of smoke on leaf function are nearly uninvestigated. The objective of this study was to compare growth and primary and secondary metabolic responses of deciduous angiosperm and evergreen conifer tree species to short smoke exposure. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.

Forest Carbon Storage in the Northern Midwest, USA: A Bottom-Up Scaling Approach Combining Local Meteorological and Biometric Data With Regional Forest Inventories

Science.gov (United States)

Curtis, P. S.; Gough, C. M.; Vogel, C. S.

2005-12-01

Carbon (C) storage increasingly is considered an important part of the economic return of forestlands, making easily parameterized models for assessing current and future C storage important for both ecosystem and money managers. For the deciduous forests of the northern midwest, USA, detailed information relating annual C storage to local site characteristics can be combined with spatially extensive forest inventories to produce simple, robust models of C storage useful at a variety of scales. At the University of Michigan Biological Station (45o35`' N, 84o42`' W) we measured C storage, or net ecosystem production (NEP), in 65 forest stands varying in age, disturbance history, and productivity (site index) using biometric methods, and independently measured net C exchange at the landscape level using meteorological methods. Our biometric and meteorological estimates of NEP converged to within 1% of each other over five years, providing important confirmation of the robustness of these two approaches applied within northern deciduous forests (Gough et al. 2005). We found a significant relationship between NEP, stand age ( A, yrs), and site index ( Is, m), where NEP = 0.134 + 0.022 * (LN[ A* Is]) (r2 = 0.50, P database (ncrs2.fs.fed.us/4801/fiadb/) to estimate forest C storage at different scales across the upper midwest, Great Lakes region. Model estimates were validated against independent estimates of C storage for other forests in the region. At the local ecosystem-level (~1 km2) C storage averaged 1.52 Mg ha-1 yr-1. Scaling to the two-county area surrounding our meteorological and biometric study sites, average stand age decreased and site index increased, resulting in estimated storage of 1.62 Mg C ha-1 yr-1, or 0.22 Tg C yr-1 in the 1350 km2 of deciduous forest in this area. For the state of Michigan (31,537 km2 of deciduous forest), average uptake was estimated at 1.55 Mg C ha-1 yr-1, or 4.9 Tg C yr-1 total storage. For the three state region encompassing

Evolutionarily stable strategy of carbon and nitrogen investments in forest leaves and its application in vegetation dynamic modeling

Science.gov (United States)

Weng, E.; Farrior, C.; Dybzinski, R.; Pacala, S. W.

2015-12-01

Leaf mass per area (LMA) and leaf lifespan (LL) are two highly correlated plant traits that are key to plant physiological and ecological properties. Usually, low LMA means short LL, high nitrogen (N) content per unit mass, and fast turnover rates of nutrients; high LMA leads to long LL, low N content, and slow turnover rates. Deciduous trees with low LMA and short lifespan leaves have low carbon cost but high nitrogen demand; and evergreen trees, with high LMA and long lifespan leaves, have high carbon cost but low nitrogen demand. These relationships lead to: 1) evergreen trees have higher leaf area index than deciduous trees; 2) evergreen trees' carbon use efficiency is lower than the deciduous trees' because of their thick leaves and therefore high maintenance respiration; 3) the advantage of evergreens trees brought by their extra leaves over deciduous trees diminishes with increase N in ecosystem. These facts determine who will win when trees compete with each other in a N-limited ecosystem. In this study, we formulate a mathematical model according to the relationships between LMA, LL, leaf nitrogen, and leaf building and maintenance cost, where LMA is the fundamental variable determining the other three. We analyze the evolutionarily stable strategies (ESSs) of LMA with this mathematical model by examining the benefits of carbon and nitrogen investments to leaves in ecosystems with different N. The model shows the ESS converges to low LMA at high N and high LMA at low N. At intermediate N, there are two ESSs at low and high ends of LMA, respectively. The ESS also leads to low forest productivity by outcompeting the possible high productive strategies. We design a simulation scheme in an individual-based competition model (LM3-PPA) to simulate forest dynamics as results of the competition between deciduous and evergreen trees in three different biomes, which are temperate deciduous forest, deciduous-evergreen mixed forest, and boreal evergreen forest. The

Human decidual stromal cells secrete soluble pro-apoptotic factors during decidualization in a cAMP-dependent manner.

Science.gov (United States)

Leno-Durán, E; Ruiz-Magaña, M J; Muñoz-Fernández, R; Requena, F; Olivares, E G; Ruiz-Ruiz, C

2014-10-10

Is there a relationship between decidualization and apoptosis of decidual stromal cells (DSC)? Decidualization triggers the secretion of soluble factors that induce apoptosis in DSC. The differentiation and apoptosis of DSC during decidualization of the receptive decidua are crucial processes for the controlled invasion of trophoblasts in normal pregnancy. Most DSC regress in a time-dependent manner, and their removal is important to provide space for the embryo to grow. However, the mechanism that controls DSC death is poorly understood. The apoptotic response of DSC was analyzed after exposure to different exogenous agents and during decidualization. The apoptotic potential of decidualized DSC supernatants and prolactin (PRL) was also evaluated. DSC lines were established from samples of decidua from first trimester pregnancies. Apoptosis was assayed by flow cytometry. PRL production, as a marker of decidualization, was determined by enzyme-linked immunosorbent assay. DSCs were resistant to a variety of apoptosis-inducing substances. Nevertheless, DSC underwent apoptosis during decidualization in culture, with cAMP being essential for both apoptosis and differentiation. In addition, culture supernatants from decidualized DSC induced apoptosis in undifferentiated DSC, although paradoxically these supernatants decreased the spontaneous apoptosis of decidual lymphocytes. Exogenously added PRL did not induce apoptosis in DSC and an antibody that neutralized the PRL receptor did not decrease the apoptosis induced by supernatants. Further studies are needed to examine the involvement of other soluble factors secreted by decidualized DSC in the induction of apoptosis. The present results indicate that apoptosis of DSC occurs in parallel to differentiation, in response to decidualization signals, with soluble factors secreted by decidualized DSC being responsible for triggering cell death. These studies are relevant in the understanding of how the regression of decidua

Investigation of radioactive cesium transportation from forest canopy to floor by litterfall, stemflow and throughfall in northern Fukushima

Science.gov (United States)

Endo, I.; Ohte, N.; Iseda, K.; Tanoi, K.; Hirose, A.; Kobayashi, N. I.; Murakami, M.; Tokuchi, N.; Ohashi, M.

2015-12-01

After the Fukushima Daiichi nuclear power plant accident due to Great East Japan Earthquake in March 11th 2011, large areas of forest have been highly contaminated by the radioactive nuclides. Most of the deposited radioactive material to the canopy is then washed out with rainfall or leaf fall due to the tree phenology. There have been studies showing that the amount of 137Cs transportation differs among litter components and water pathways, and was affected by seasonal variations. Thus, to evaluate the amount of 137Cs flux from canopy to forest floor, continuous monitoring of each component (litterfall, throughfall and stemflow) is required. We investigated the annual transfer of 137Cs from the forest canopy to the floor by litterfall, throughfall and stemflow at two different forest types in northern Fukushima after two years from the accident. Seasonal variations in 137Cs transportation and differences between forests types were also determined. Forest sites were set in the upstream part of Kami-Oguni River catchment at Date city, which locates approximately 50km northwest from the Fukushima Dai-ichi Nuclear Power Plant. The study sites consisted of two deciduous (Mixed deciduous-1, Mixed deciduous-2) and one cedar (Cedar plantation) stands. The cumulative 137Cs transportation from the forest canopy to the floor was 6.6 kBq m-2 year-1 for the Mixed deciduous-1, 3.9 kBq m-2 year-1 for the Mixed deciduous-2 and 11.0 kBq m-2 year-1 for the Cedar plantation. 137Cs transportation with litterfall increased in the defoliation period which correlated with the increased amount of litterfall. 137Cs transportation with throughfall and stemflow increased in the rainy season. 137Cs flux by litterfall was higher in Cedar plantation compared with that of mixed deciduous forests, while the opposite result was obtained for stemflow. The ratio of annual 137Cs flux and the estimated 137Cs amount deposited in the forests will be discussed.

The Atmospheric Chemistry and Canopy Exchange Simulation System (ACCESS: model description and application to a temperate deciduous forest canopy

Directory of Open Access Journals (Sweden)

R. D. Saylor

2013-01-01

Full Text Available Forest canopies are primary emission sources of biogenic volatile organic compounds (BVOCs and have the potential to significantly influence the formation and distribution of secondary organic aerosol (SOA mass. Biogenically-derived SOA formed as a result of emissions from the widespread forests across the globe may affect air quality in populated areas, degrade atmospheric visibility, and affect climate through direct and indirect forcings. In an effort to better understand the formation of SOA mass from forest emissions, a 1-D column model of the multiphase physical and chemical processes occurring within and just above a vegetative canopy is being developed. An initial, gas-phase-only version of this model, the Atmospheric Chemistry and Canopy Exchange Simulation System (ACCESS, includes processes accounting for the emission of BVOCs from the canopy, turbulent vertical transport within and above the canopy and throughout the height of the planetary boundary layer (PBL, near-explicit representation of chemical transformations, mixing with the background atmosphere and bi-directional exchange between the atmosphere and canopy and the atmosphere and forest floor. The model formulation of ACCESS is described in detail and results are presented for an initial application of the modeling system to Walker Branch Watershed, an isoprene-emission-dominated forest canopy in the southeastern United States which has been the focal point for previous chemical and micrometeorological studies. Model results of isoprene profiles and fluxes are found to be consistent with previous measurements made at the simulated site and with other measurements made in and above mixed deciduous forests in the southeastern United States. Sensitivity experiments are presented which explore how canopy concentrations and fluxes of gas-phase precursors of SOA are affected by background anthropogenic nitrogen oxides (NO_x. Results from these experiments suggest that the

ABOVEGROUND BIOMASS DISTRIBUTION OF US EASTERN HARDWOOD FORESTS AND THE USE OF LARGE TREES AS AN INDICATOR OF FOREST DEVELOPMENT

Science.gov (United States)

Past clearing and harvesting of the deciduous hardwood forests of eastern USA released large amount of carbon dioxide into the atmosphere, but through recovery and regrowth these forests are now accumulating atmospheric carbon (C). This study examined quantities and distribution ...

Decidual-secreted factors alter invasive trophoblast membrane and secreted proteins implying a role for decidual cell regulation of placentation.

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Ellen Melaleuca Menkhorst

Full Text Available Inadequate or inappropriate implantation and placentation during the establishment of human pregnancy is thought to lead to first trimester miscarriage, placental insufficiency and other obstetric complications. To create the placental blood supply, specialized cells, the 'extravillous trophoblast' (EVT invade through the differentiated uterine endometrium (the decidua to engraft and remodel uterine spiral arteries. We hypothesized that decidual factors would regulate EVT function by altering the production of EVT membrane and secreted factors. We used a proteomics approach to identify EVT membrane and secreted proteins regulated by decidual cell factors. Human endometrial stromal cells were decidualized in vitro by treatment with estradiol (10(-8 M, medroxyprogesterone acetate (10(-7 M and cAMP (0.5 mM for 14 days. Conditioned media (CM was collected on day 2 (non-decidualized CM and 14 (decidualized CM of treatment. Isolated primary EVT cultured on Matrigel™ were treated with media control, non-decidualized or decidualized CM for 16 h. EVT CM was fractionated for proteins <30 kDa using size-exclusion affinity nanoparticles (SEAN before trypsin digestion and HPLC-MS/MS. 43 proteins produced by EVT were identified; 14 not previously known to be expressed in the placenta and 12 which had previously been associated with diseases of pregnancy including preeclampsia. Profilin 1, lysosome associated membrane glycoprotein 1 (LAMP1, dipeptidyl peptidase 1 (DPP1/cathepsin C and annexin A2 expression by interstitial EVT in vivo was validated by immunhistochemistry. Decidual CM regulation in vitro was validated by western blotting: decidualized CM upregulated profilin 1 in EVT CM and non-decidualized CM upregulated annexin A2 in EVT CM and pro-DPP1 in EVT cell lysate. Here, non-decidualized factors induced protease expression by EVT suggesting that non-decidualized factors may induce a pro-inflammatory cascade. Preeclampsia is a pro

Indirect estimations and spatial variation in leaf area index of coniferous, deciduous and mixed forest stands in Forsmark and Laxemar

International Nuclear Information System (INIS)

Tagesson, Torbern

2006-12-01

Two sites in Sweden are investigated for a potential deep repository of the nuclear waste, the Laxemar investigation area (57 deg 5 min N, 16 deg 7 min E) and the Forsmark investigation area (60 deg 4 min N, 18 deg 2 min E). In the characterisation of these sites, development of site descriptive models is an important part. Leaves are the main surface were an exchange of matter and energy between the atmosphere and the biosphere takes place, and leaf area index (LAI) of the vegetation cover is an important variable correlated to a number of ecophysiological parameters and hereby an important parameter in ecosystem models. In the investigation areas, LAI of boreal and temperate ecosystems were therefore estimated indirectly through optical measurements using the LAI-2000 (LI-COR, Cambridge UK) and TRAC (Tracing Radiation and Architecture of Canopies). On average, measured maximum LAI was 3.40 in Laxemar and 3.43 in Forsmark; minimum LAI was 1.65 in Laxemar and 1.97 in Forsmark. Forest inventory data showed that LAI is positively correlated with basal area, stand height, stand volume and breast height tree diameter. For the coniferous stands, there was also a linearly negative relationship with age. In the Laxemar investigation area, there were no significant relationships for LAI with a satellite derived kNN (kNearest Neighbor) data set with stand height, stand volume and stand age. The kNN data set can therefore not be used to extrapolate measured LAI over the Laxemar investigation area. There were significant relationships between LAI and the normalized difference vegetation index (NDVI) for coniferous, deciduous and mixed forest stands in the Laxemar investigation area. A NDVI image could be used to extrapolate LAI over the entire investigation area. For the Forsmark investigation area, effective LAI for all stands were correlated to NDVI and this relationship could then be used for extrapolation. The effective LAI image was afterwards corrected for average

Indirect estimations and spatial variation in leaf area index of coniferous, deciduous and mixed forest stands in Forsmark and Laxemar

Energy Technology Data Exchange (ETDEWEB)

Tagesson, Torbern [Dept. of Physical Geography and Ecosystem Analysis, Lund Univ., Lund (Sweden)

2006-12-15

Two sites in Sweden are investigated for a potential deep repository of the nuclear waste, the Laxemar investigation area (57 deg 5 min N, 16 deg 7 min E) and the Forsmark investigation area (60 deg 4 min N, 18 deg 2 min E). In the characterisation of these sites, development of site descriptive models is an important part. Leaves are the main surface were an exchange of matter and energy between the atmosphere and the biosphere takes place, and leaf area index (LAI) of the vegetation cover is an important variable correlated to a number of ecophysiological parameters and hereby an important parameter in ecosystem models. In the investigation areas, LAI of boreal and temperate ecosystems were therefore estimated indirectly through optical measurements using the LAI-2000 (LI-COR, Cambridge UK) and TRAC (Tracing Radiation and Architecture of Canopies). On average, measured maximum LAI was 3.40 in Laxemar and 3.43 in Forsmark; minimum LAI was 1.65 in Laxemar and 1.97 in Forsmark. Forest inventory data showed that LAI is positively correlated with basal area, stand height, stand volume and breast height tree diameter. For the coniferous stands, there was also a linearly negative relationship with age. In the Laxemar investigation area, there were no significant relationships for LAI with a satellite derived kNN (kNearest Neighbor) data set with stand height, stand volume and stand age. The kNN data set can therefore not be used to extrapolate measured LAI over the Laxemar investigation area. There were significant relationships between LAI and the normalized difference vegetation index (NDVI) for coniferous, deciduous and mixed forest stands in the Laxemar investigation area. A NDVI image could be used to extrapolate LAI over the entire investigation area. For the Forsmark investigation area, effective LAI for all stands were correlated to NDVI and this relationship could then be used for extrapolation. The effective LAI image was afterwards corrected for average

Responses of Soil Acid Phosphomonoesterase Activity to Simulated Nitrogen Deposition in Three Forests of Subtropical China

Institute of Scientific and Technical Information of China (English)

HUANG Wen-Juan; LIU Shi-Zhong; CHU Guo-Wei; ZHANG De-Qiang; LI Yue-Lin; LU Xian-Kai; ZHANG Wei; HUANG Juan; D. OTIENO; Z. H. XU; LIU Ju-Xiu

2012-01-01

Soil acid phosphomonoesterase activity (APA) plays a vital role in controlling phosphorus (P) cycling and reflecting the current degree of P limitation Responses of soil APA to elevating nitrogen (N) deposition are important because of their potential applications in addressing the relationship between N and P in forest ecosystems.A study of responses of soll APA to simulated N deposition was conducted in three succession forests of subtropical China.The three forests include a Masson pine (Pinus massoniana) forest (MPF)—pioneer community,a coniferous and broad-leaved mixed forest (MF)—transition community and a monsoon evergreen broadleaved forest (MEBF)—climax community.Four N treatments were designed for MEBF:control (without N added),low-N (50 kg N ha-1 year-1),and medium-N (100 kg N ha-1 year-1) and high-N (150 kg N ha-1 year-1),and only three N treatments (i.e.,control,low-N,mediun-N) were established for MPF and MF.Results showed that soil APA was highest in MEBF.followed by MPF and MF.Soil APAs in both MPF and MF were not influenced by low-N treatments but depressed in medium-N trcatments.However,soil APA in MEBF exhibited negative responses to high N additions,indicating that the environment of enhanced N depositions would reduce P supply for the mature forest ecosystem.Soil APA and its responses to N additions in subtropical forests were closely related to the succession stages in the forests.

Consequences of forest energy for flora

International Nuclear Information System (INIS)

Kruuse, A.

1992-01-01

The report examines the effects of forest energy on the field layer vegetation, and includes whole-tree harvesting, liming, fertilization, wood ash distribution and the importance of broadleaved trees. Whole-tree harvesting is negative for some of the vascular plant species, and positive for others, and can have a drastically negative effect on lichens, mosses and decomposing fungi. Whole-tree harvesting can be accepted from the viewpoint of the flora if: - between 10 and 30 % of the slash is left on the clearcut area, - hardwood stands or mixed stands with hardwood are excepted from whole-tree harvesting, - dead lying or standing trees, a few broadleaved trees and old trees, are left on the clearcut area. Liming has some effects on the flora, especially a very negative effect on lichens and mosses. Liming can be accepted if; - it only takes place where whole-tree harvesting has been used or where acidification caused by air pollution has been observed, - the amounts are moderate, 2 to 4 tonnes/ha, and the liming material has a rather large grain size, - it is unevenly distributed, and - it is avoided in naturally acid stands with a special vegetation. Fertilization has negative effects on all the considered vegetation groups. It can only be accepted as compensation for whole-tree harvesting, and no more nitrogen must be added than is taken away in the harvest. In southern Sweden even the compensatory fertilization should be avoided. The consequences of wood ash distribution are little known. Until more facts are presented, only enough wood ash as to compensate for the loss through whole-tree harvesting should be distributed. If the use of forest energy would lead to an increase of the broadleaved tree ratio it would be positive. (54 refs.)

Variability of the soil seed banks in the natural deciduous forest in the Białowieża National Park

Directory of Open Access Journals (Sweden)

Małgorzata Jankowska-Błaszczuk

2014-01-01

Full Text Available Using the germination method, the species diversity, density of the soil seed bank and its relation to cover vegetation in a natural deciduous forest with primary and secondary tree stand were compared. It was found that the mean density and species composition of the soil seed bank in the forest with secondary tree stand that has spontaneously been overgrown over the last 90 years after clear-cutting does not differ from the soil seed bank derived from primeval forest (3167M-2 vs. 3827m-2. In both stands there were 46 species altogether and 36 were common and seed banks were dominated by herbs. The most abundant in this group were: Urtica dioica, Chrysosplenium alternifolium, Geranium robertianum, Oxalis acetosella. In both cases it was found that the species structure of the herb layer was similar to that of the seed bank in about 70%. The seed banks of species absent from the herb layer or present there only sporadically were much more abundant. The seedlings of these species constituted more than one third of all seedlings that emerged in the samples from the secondary tree stand and only 5% those from the primary one. The analysis of seed bank in heavily rooted places under primary and secondary tree stands showed that in places with a totally distroyed herb layer the density of the soil seed bank in primeval forest was three times lower than in places with fully developed herb layer structure (102.60±22.61 vs. 307.0±206.5 per sample. This difference under secondary tree stand turned out to be much lower (415.8±137.8 vs. 358.2±126.0 per sample.

Near-natural forests in southern Sweden. Palaeoecological and silvicultural aspects on nature-based silviculture

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Bjoerse, Gisela [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden). Southern Swedish Forest Research Centre

2000-07-01

Timber production and protection of biodiversity are two main issues in south Swedish forestry. This thesis explores the possibilities of combining the two issues in a nature-based silviculture. Different branches of science, palaeoecology, silviculture and forest vegetation ecology, were combined to give a multidisciplinary approach to the subject. Mimicking the historical forest composition and processes in the silvicultural measures for the benefit of both biodiversity protection and timber production was identified as one possible way of developing a nature-based silviculture. The long period of human influence on the landscape in southern Sweden has effectively removed all the remnants of natural forest that could have been used as references in the mimicking procedure. Consequently, historical references were searched. A method to describe former forest conditions was developed using palaeoecological data and methods. It was found that the historical deciduous dominance was pronounced. Over 2000 years southern Sweden has been transformed from a deciduous to a coniferous landscape. Human activities were shown to be a major driving force in this change. Several detected historical forest types were possible as references for the mimicking approach, but forest types common in the past and rare today were suggested for maximal efficiency in obtaining high biodiversity. Mixed nemoral deciduous forests were pointed out as a historically widespread forest type with very little resemblance in the present landscape. The small fragments left are important for present biodiversity and from many other aspects. Development of a nature-based silvicultural system for the management of mixed nemoral forest stands based on the theory of mimicking was begun. A silvicultural experiment was established in a near-natural, mixed nemoral forest stand in southern Sweden and the early effects of the silvicultural treatments tested were evaluated with regard to floristic diversity

CHANGES IN SOIL MACROFAUNA IN AGROECOSYSTEMS DERIVED FROM LOW DECIDUOUS TROPICAL FOREST ON LEPTOSOLS FROM KARSTIC ZONES

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Francisco Bautista

2009-02-01

Full Text Available In Yucatan Mexico the method of slash and burn is used for the establishment of pastures. Pastures are developed for 15 to 20 years, no more because weed control is too expensive. The impact of these practices on soil macrofauna had not been evaluated. Because of its wide distribution, diverse habits and high sensitivity to disturbance, soil macrofauna is considered a valuable indicator of soil health, allowing monitoring of soil sustainability. We studied soil macrofauna communities in low deciduous tropical forest and four livestock agroecosystems with increasing management-derived disturbance including a silvopastoral system, Taiwan grass (Cynodon nlemfuensis and Star grass (Pennisetum purpureum pastures in order to describe community structure across systems, and evaluate disturbance sensitivity of taxonomical groups to detect taxa with potential use as biological indicators of soil health or degradation. Pitfall traps were used at each of the systems to sample soil macrofauna. We estimate their taxonomical abundance, biomass, richness (order, morphospecies, diversity, dominance and response to disturbance on agroecosystems and the forest. We found 133 macrofauna morphospecies of 15 taxa. Groups with more individuals were: Hymenoptera (64.97%, Coleoptera (22.68%, and Orthoptera (3.91%.  Agroecosystem of two-year old Taiwan-grass pasture (TP2 had the highest macrofauna abundances, biomass and richness, low diversity, and a non-homogeneous distribution of individuals among species; in contrast, silvopastoral system (SP, had low abundance and biomass, the lowest specific richness, high diversity and a homogeneous distribution of individuals among species. The discriminant analysis revealed that the agroecosystems and the forest serve to predict the macrofauna communities, since they have particular or typical soil macrofauna. The cases (sampled points with a correct assignation by agroecosystems were: Forest (70%, Sivopastoral system (70

Leaf traits show different relationships with shade tolerance in moist versus dry tropical forests.

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Poorter, Lourens

2009-03-01

Shade tolerance is the central paradigm for understanding forest succession and dynamics, but there is considerable debate as to what the salient features of shade tolerance are, whether adult leaves show similar shade adaptations to seedling leaves, and whether the same leaf adaptations are found in forests under different climatic control. Here, adult leaf and metamer traits were measured for 39 tree species from a tropical moist semi-evergreen forest (1580 mm rain yr(-1)) and 41 species from a dry deciduous forest (1160 mm yr(-1)) in Bolivia. Twenty-six functional traits were measured and related to species regeneration light requirements.Adult leaf traits were clearly associated with shade tolerance. Different, rather than stronger, shade adaptations were found for moist compared with dry forest species. Shade adaptations exclusively found in the evergreen moist forest were related to tough and persistent leaves, and shade adaptations in the dry deciduous forest were related to high light interception and water use.These results suggest that, for forests differing in rainfall seasonality, there is a shift in the relative importance of functional leaf traits and performance trade-offs that control light partitioning. In the moist evergreen forest leaf traits underlying the growth-survival trade-off are important, whereas in the seasonally deciduous forest leaf traits underlying the growth trade-off between low and high light might become important.

[Estimation of carbonaceous gases emission from forest fires in Xiao Xing'an Mountains of Northeast China in 1953-2011].

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Hu, Hai-Qing; Luo, Bi-Zhen; Wei, Shu-Jing; Sun, Long; Wei, Shu-Wei; Wen, Zheng-Min

2013-11-01

Based on the forest resources investigation data and the forest fire inventory in 1953-2011, in combining with our field research in burned areas and our laboratory experiments, this paper estimated the carbonaceous gases carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), and nonmethane hydrocarbons (NMHC) emission from the forest fires in Xiao Xing' an Mountains of Heilongjiang Province, Northeast China in 1953-2011. The total carbon emission from the forest fires in the Xiao Xing'an Mountains in 1953-2011 was 1.12 x 10(7) t, and the annual emission was averagely 1.90 x10(5) t, accounting for 1.7% of the annual average total carbon emission from the forest fires in China. The emission of CO2, CO, CH4, and NMHC was 3.39 x 10(7), 1.94 x 10(5), 1.09 x 10(5), and 7.46 x 10(4) t, respectively, and the corresponding annual average emission was 5.74 x 10(5), 3.29 x 10(4), 1.85 x 10(3), and 1.27 x 10(3) t, accounting for 1.4%, 1.2%, 1.7%, and 1.1% of the annual carbonaceous gases emitted from the forest fires in China, respectively. The combustion efficiency and the carbon emission per unit burned area of different forest types decreased in order of coniferous forest > broad-leaved forest > coniferous broadleaved mixed forest. Some rational forest fire management measures were put forward.

[Temperature sensitivity of soil organic carbon mineralization and β-glucosidase enzymekinetics in the northern temperate forests at different altitudes, China].

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Fan, Jin-juan; Li, Dan-dan; Zhang, Xin-yu; He, Nian-peng; Bu, Jin-feng; Wang, Qing; Sun, Xiao-min; Wen, Xue-fa

2016-01-01

Soil samples, which were collected from three typical forests, i.e., Betula ermanii forest, coniferous mixed broad-leaved forest, and Pinus koraiensis forest, at different altitudes along the southern slope of Laotuding Mountain of Changbai Mountain range in Liaoning Province of China, were incubated over a temperature gradient in laboratory. Soil organic carbon mineralization rates (Cmin), soil β-1,4-glucosidase (βG) kinetics and their temperature sensitivity (Q₁₀) were measured. The results showed that both altitude and temperature had significant effects on Cmin · Cmin increased with temperature and was highest in the B. ermanii forest. The temperature sensitivity of Cmin [Q₁₀(Cmin)] ranked in order of B. ermanii forest > P. koraiensis forest > coniferous mixed broad-leaved forest, but did not differ significantly among the three forests. Both the maximum activity (Vmax) and the Michaelis constant (Km) of the βG responded positively to temperature for all the forests. The temperature sensitivity of Vmax [Q₁₀(Vmax)] ranged from 1.78 to 1.90, and the temperature sensitivity of Km [Q₁₀(Km)] ranged from 1.79 to 2.00. The Q₁₀(Vmax)/Q10(Km) ratios were significantly greater in the B. ermanii soil than in the other two forest soils, suggesting that the βG kinetics-dependent impacts of the global warming or temperature increase on the decomposition of soil organic carbon were temperature sensitive for the forests at the higher altitudes.

Seasonal dynamics of water use efficiency of typical forest and grassland ecosystems in China

CERN Document Server

Zhu, Xianjin; Wang, Qiufeng; Hu, Zhongmin; Han, Shijie; Yan, Junhua; Wang, Yanfen; Zhao, Liang

2014-01-01

We selected four sites of ChinaFLUX representing four major ecosystem types in China-Changbaishan temperate broad-leaved Korean pine mixed forest (CBS), Dinghushan subtropical evergreen broadleaved forest (DHS), Inner Mongolia temperate steppe (NM), and Haibei alpine shrub-meadow (HBGC)-to study the seasonal dynamics of ecosystem water use efficiency (WUE = GPP/ET, where GPP is gross primary productivity and ET is evapotranspiration) and factors affecting it. Our seasonal dynamics results indicated single-peak variation of WUE in CBS, NM, and HBGC, which were affected by air temperature (Ta) and leaf area index (LAI), through their effects on the partitioning of evapotranspiration (ET) into transpiration (T) (i.e., T/ET). In DHS, WUE was higher at the beginning and the end of the year, and minimum in summer. Ta and soil water content affected the seasonal dynamics of WUE through their effects on GPP/T. Our results indicate that seasonal dynamics of WUE were different because factors affecting the seasonal dyn...

[Characteristics of floor litter and soil arthropod community in different types ot subtropical forest in Ailao Mountain of Yunnan, Southwest China].

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Yang, Zhao; Yang, Xiao-Dong

2011-11-01

By using line transect method, an investigation was conducted on the floor litter and soil arthropod community in a mid mountain wet evergreen broad-leaved forest, a mossy dwarf forest, and a Populus bonatii forest in Ailao Mountain of Yunnan in April (dry and hot season), June (rainy season), and December (dry and cold season), 2005. In both dry and rainy seasons, the existing floor litter mass, C storage, and C/N ratio in the three forests all increased in the order of mossy dwarf forest > P. bonatii forest > evergreen broad-leaved forest, but the N storage had less difference. In the floor litter layer of the forests, Acari and Collembola were the dominant groups of soil arthropod community, while Diptera larvae, Coleoptera, ants, and Homoptera were the common groups. The Sorenson coefficients of soil arthropod community in the three forests were extremely great. No significant differences were observed in the soil arthropod density (ind x m(-2)) in the floor litter layer among the three forests, but the relative density (ind x g(-1)) of soil arthropods was higher in the evergreen broad-leaved forest and P. bonatii forest than in the mossy dwarf forest. In the three forests, the density of soil arthropods was significantly higher in dry season than in rainy season, but the Shannon diversity index had less difference. There were significant positive correlations between the existing floor litter mass and the individual density (ind x m(-2)) and dominant groups of soil arthropod communities in dry and hot season (April), but negative correlations between the existing floor litter mass and the relative density (ind x g(-1)) of soil arthropod communities and Acari in dry and cold season (December). The individual densities of Collembola and Coleoptera also had positive correlations with the N storage of the existing floor litter mass in the three forests. It was considered that the floor litter and the development of soil arthropod community in the litter layer of

Fast changes in seasonal forest communities due to soil moisture increase after damming

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Vagner Santiago do Vale

2013-12-01

Full Text Available Local changes caused by dams can have drastic consequences for ecosystems, not only because they change the water regime but also the modification on lakeshore areas. Thus, this work aimed to determine the changes in soil moisture after damming, to understand the consequences of this modification on the arboreal community of dry forests, some of the most endangered systems on the planet. We studied these changes in soil moisture and the arboreal community in three dry forests in the Araguari River Basin, after two dams construction in 2005 and 2006, and the potential effects on these forests. For this, plots of 20m x10m were distributed close to the impoundment margin and perpendicular to the dam margin in two deciduous dry forests and one semi-deciduous dry forest located in Southeastern Brazil, totaling 3.6ha sampled. Besides, soil analysis were undertaken before and after impoundment at three different depths 0-10, 20-30 and 40-50cm. A tree minimum DBH of 4.77cm community inventory was made before T0 and at two T2 and four T4 years after damming. Annual dynamic rates of all communities were calculated, and statistical tests were used to determine changes in soil moisture and tree communities. The analyses confirmed soil moisture increases in all forests, especially during the dry season and at sites closer to the reservoir; besides, an increase in basal area due to the fast growth of many trees was observed. The highest turnover occurred in the first two years after impoundment, mainly due to the higher tree mortality especially of those closer to the dam margin. All forests showed reductions in dynamic rates for subsequent years T2-T4, indicating that these forests tended to stabilize after a strong initial impact. The modifications were more extensive in the deciduous forests, probably because the dry period resulted more rigorous in these forests when compared to semideciduous forest. The new shorelines created by damming increased soil

ESTIMATION OF CARBON SEQUESTRATION BY RUSSIAN FORESTS: GEOSPATIAL ISSUE

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N. V. Malysheva

2017-01-01

Full Text Available Сategories of carbon sequestration assessment for Russian forests are identified by GIS toolkit. Those are uniform by bioclimatic and site-specific conditions strata corresponding to modern version of bioclimatic forest district division. Stratification of forests at early stage substantially reduces the ambiguity of the evaluation because phytomass conversion sequestration capacity and expansion factor dependent on site-specific condition for calculating of forest carbon sink are absolutely necessary. Forest management units were linked to strata. Biomass conversion and expansion factor for forest carbon sink assessment linked to the strata were recalculated for forest management units. All operations were carried out with GIS analytical toolkit due to accessible functionalities. Units for forest carbon storage inventory and forest carbon balance calculation were localized. Production capacity parameters and forest carbon sequestration capacity have been visualized on maps complied by ArcGIS. Based on spatially-explicit information, we have found out that the greatest annual rates of forest’s carbon accumulation in Russian forests fall into mixed coniferous-deciduous forests of European-Ural part of Russia to Kaliningrad, Smolensk and Briansk Regions, coniferous-deciduous forests close to the boundary of Khabarovsk Region and Primorskij Kray in the Far East, as well as separate forest management units of Kabardino-Balkariya NorthCaucasian mountain area. The geospatial visualization of carbon sequestration by Russian forests and carbon balance assessment has been given.

Florística e estrutura da comunidade arbórea de um remanescente de Floresta Estacional Decidual de encosta, Monte Alegre, GO, Brasil Floristic and structure of a seasonal deciduous forest fragment, Monte Alegre, GO, Brazil

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André R. Terra Nascimento

2004-09-01

Full Text Available O presente estudo teve como objetivo descrever a composição de espécies arbóreas e a estrutura de um fragmento de Floresta Estacional Decidual, na região Nordeste de Goiás, Brasil. Foram levantadas 25 unidades amostrais quadradas de 20x20m, totalizando uma amostra de um hectare, sendo incluídos na amostragem todos os indivíduos com diâmetros iguais ou superiores a 5cm. Foram amostrados 663 indivíduos pertencentes a 52 espécies arbóreas, destacando-se pela densidade as espécies Combretum duarteanum Camb., Casearia rupestris Eichl., Myracrodruon urundeuva Fr. Allem., Machaerium acutifolium Vog. e Tabebuia impetiginosa (Mart. ex DC. Standl. Foram encontradas 21 famílias botânicas, com maior representatividade da família Leguminosae (17 espécies e das famílias Bignoniaceae (4 espécies, Anacardiaceae (3 espécies e Bombacaceae (3 espécies. A vegetação estudada apresentou dossel descontínuo e distribuição diamétrica desequilibrada, com valores do quociente de Liocourt "q" variando de q1= 0,66 a q6 = 0,14. Estes remanescentes florestais desempenham papel importante na manutenção da diversidade biológica e possuem espécies arbóreas madeiráveis de importância econômica, que se tornaram raras em outros locais da região Nordeste de Goiás.The objective of this study was to describe the floristic composition and the structure of the tree layer of a fragment of a seasonal deciduous forest in northeastern Goiás state, Brazil. A sample of 25 (20x20 plots was assessed totaling one hectare. All individuals for 5cm dbh were included in the survey. A total of 663 trees in 52 arboreal species was found; the most abundant species were Combretum duarteanum Camb., Casearia rupestris Eichl., Myracrodruon urundeuva Fr. Allem., Machaerium acutifolium Vog. and Tabebuia impetiginosa (Mart. ex DC. Standl. There were 21 families with a higher proportion of Leguminosae (17 species Bignoniaceae (4 species, Anacardiaceae (3 species and

Decidual cell polyploidization necessitates mitochondrial activity.

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Xinghong Ma

Full Text Available Cellular polyploidy has been widely reported in nature, yet its developmental mechanism and function remain poorly understood. In the present study, to better define the aspects of decidual cell polyploidy, we isolated pure polyploid and non-polyploid decidual cell populations from the in vivo decidual bed. Three independent RNA pools prepared for each population were then subjected to the Affymetrix gene chip analysis for the whole mouse genome transcripts. Our data revealed up-regulation of 1015 genes and down-regulation of 1207 genes in the polyploid populations, as compared to the non-polyploid group. Comparative RT-PCR and in situ hybridization results indeed confirmed differential expressional regulation of several genes between the two populations. Based on functional enrichment analyses, up-regulated polyploidy genes appeared to implicate several functions, which primarily include cell/nuclear division, ATP binding, metabolic process, and mitochondrial activity, whereas that of down-regulated genes primarily included apoptosis and immune processes. Further analyses of genes that are related to mitochondria and bi-nucleation showed differential and regional expression within the decidual bed, consistent with the pattern of polyploidy. Consistently, studies revealed a marked induction of mitochondrial mass and ATP production in polyploid cells. The inhibition of mitochondrial activity by various pharmacological inhibitors, as well as by gene-specific targeting using siRNA-mediated technology showed a dramatic attenuation of polyploidy and bi-nucleation development during in vitro stromal cell decidualization, suggesting mitochondria play a major role in positive regulation of decidual cell polyploidization. Collectively, analyses of unique polyploidy markers and molecular signaling networks may be useful to further characterize functional aspects of decidual cell polyploidy at the site of implantation.

Modern analogues from the Southern Urals provide insights into biodiversity change in the early Holocene forests of Central Europe

Czech Academy of Sciences Publication Activity Database

Chytrý, M.; Danihelka, Jiří; Horsák, M.; Kočí, M.; Kubešová, S.; Lososová, Z.; Otýpková, Z.; Tichý, L.; Martynenko, V. B.; Baisheva, E. Z.

2010-01-01

Roč. 37, č. 4 (2010), s. 767-780 ISSN 0305-0270 Institutional research plan: CEZ:AV0Z60050516 Keywords : bryophytes * broad-leaved trees * mixed oak forests Subject RIV: EF - Botanics Impact factor: 4.273, year: 2010

Forest Dynamics in the Eastern Ghats of Tamil Nadu, India

Science.gov (United States)

Jayakumar, S.; Ramachandran, A.; Bhaskaran, G.; Heo, J.

2009-02-01

The primary deciduous forests in the Eastern Ghats (EG) of Tamil Nadu (TN) India have undergone many changes owing to various need-based forest managements, such as timber extraction for industry, railway sleepers, charcoal, and forest clearance for hydroelectric projects and agriculture, during preindependence and postindependence periods (i.e., from 1800 to 1980). The enactment of a forest conservation act during the 1980s changed the perception of forest managers from utilization to conservation. This study was taken up to assess the forests dynamics in the EG of TN spatially between 1990 and 2003 and nonspatially between 1900 and the 1980s. Landsat Thematic Mapper (TM) and Indian Remote Sensing satellite (IRS) 1D Linear Imaging and Self Scanning (LISS III) data were used to assess forests during 1990 and 2003, respectively. Field floristic survey and secondary data (such as published literature, floras, books, and forest working plans) were used to assess the forest dynamics in terms of forest type and species composition among the preindependence period, the postindependence period, and the present (i.e., before and after 1980). The satellite data analysis revealed a considerable amount of changes in all forest types during the 13 years. The comparison of species composition and forest types between the past and present revealed that need-based forest management along with anthropogenic activity have altered the primary deciduous forest in to secondary and postextraction secondary forests such as southern thorn and southern thorn scrub forests in the middle [400-900 m above mean sea level (MSL)] and lower slopes (900 m MSL) and plateau seemed not to be much affected by the forest management. The changes estimated by the satellite data processing in the major forest types such as evergreen, deciduous, southern thorn, and southern thorn scrub are really alarming because these changes have occurred after the implementation of a forest conservation act. The

The arboreal component of a dry forest in Northeastern Brazil

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M. J. N. Rodal

Full Text Available The dry forests of northeastern Brazil are found near the coastal zone and on low, isolated mountains inland amid semi-arid vegetation. The floristic composition of these dry montane forests, as well as their relationship to humid forests (Atlantic forest sensu stricto and to the deciduous thorn woodlands (Caatinga sensu stricto of the Brazilian northeast are not yet well known. This paper sought to determine if the arboreal plants in a dry forest growing on a low mountain in the semi-arid inland region (Serra Negra, 8° 35’ - 8° 38’ S and 38° 02’ - 38° 04’ W between the municipalities of Floresta and Inajá, state of Pernambuco have the same floristic composition and structure as that seen in other regional forests. In fifty 10 x 20 m plots all live and standing dead trees with trunk measuring > 5 cm diameter at breast height were measured. Floristic similarities between the forest studied and other regional forests were assessed using multivariate analysis. The results demonstrate that the dry forest studied can be classified into two groups that represent two major vegetational transitions: (1 a humid forest/dry forest transition; and (2 a deciduous thorn-woodland/ dry forest transition.

The arboreal component of a dry forest in Northeastern Brazil.

Science.gov (United States)

Rodal, M J N; Nascimento, L M

2006-05-01

The dry forests of northeastern Brazil are found near the coastal zone and on low, isolated mountains inland amid semi-arid vegetation. The floristic composition of these dry montane forests, as well as their relationship to humid forests (Atlantic forest sensu stricto) and to the deciduous thorn woodlands (Caatinga sensu stricto) of the Brazilian northeast are not yet well known. This paper sought to determine if the arboreal plants in a dry forest growing on a low mountain in the semi-arid inland region (Serra Negra, 8 degrees 35 - 8 degrees 38 S and 38 degrees 02 - 38 degrees 04 W) between the municipalities of Floresta and Inajá, state of Pernambuco have the same floristic composition and structure as that seen in other regional forests. In fifty 10 x 20 m plots all live and standing dead trees with trunk measuring > 5 cm diameter at breast height were measured. Floristic similarities between the forest studied and other regional forests were assessed using multivariate analysis. The results demonstrate that the dry forest studied can be classified into two groups that represent two major vegetational transitions: (1) a humid forest/dry forest transition; and (2) a deciduous thorn-woodland/ dry forest transition.

Does species richness affect fine root biomass and production in young forest plantations?

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Domisch, Timo; Finér, Leena; Dawud, Seid Muhie; Vesterdal, Lars; Raulund-Rasmussen, Karsten

2015-02-01

Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined species composition from fine root biomass samples with the near-infrared reflectance spectroscopy method. We did not observe higher biomass or production in mixed stands compared to monocultures. Neither did we observe any differences in tree root length or fine root turnover. One reason for this could be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested that functional group identity (i.e. conifers vs. broadleaved species) can be more important for below-ground biomass and production than the species richness itself, as conifers seemed to be more competitive in colonising the soil volume, compared to broadleaved species.

Vegetation in karst terrain of southwestern China allocates more biomass to roots

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Ni, J.; Luo, D. H.; Xia, J.; Zhang, Z. H.; Hu, G.

2015-07-01

In mountainous areas of southwestern China, especially Guizhou province, continuous, broadly distributed karst landscapes with harsh and fragile habitats often lead to land degradation. Research indicates that vegetation located in karst terrains has low aboveground biomass and land degradation that reduces vegetation biomass, but belowground biomass measurements are rarely reported. Using the soil pit method, we investigated the root biomass of karst vegetation in five land cover types: grassland, grass-scrub tussock, thorn-scrub shrubland, scrub-tree forest, and mixed evergreen and deciduous forest in Maolan, southern Guizhou province, growing in two different soil-rich and rock-dominated habitats. The results show that roots in karst vegetation, especially the coarse roots, and roots in rocky habitats are mostly distributed in the topsoil layers (89 % on the surface up to 20 cm depth). The total root biomass in all habitats of all vegetation degradation periods is 18.77 Mg ha-1, in which roots in rocky habitat have higher biomass than in earthy habitat, and coarse root biomass is larger than medium and fine root biomass. The root biomass of mixed evergreen and deciduous forest in karst habitat (35.83 Mg ha-1) is not greater than that of most typical, non-karst evergreen broad-leaved forests in subtropical regions of China, but the ratio of root to aboveground biomass in karst forest (0.37) is significantly greater than the mean ratio (0.26 ± 0.07) of subtropical evergreen forests. Vegetation restoration in degraded karst terrain will significantly increase the belowground carbon stock, forming a potential regional carbon sink.

Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient.

Science.gov (United States)

Orihuela, Rodrigo L L; Peres, Carlos A; Mendes, Gabriel; Jarenkow, João A; Tabarelli, Marcelo

2015-01-01

We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.

Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient.

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Rodrigo L L Orihuela

Full Text Available We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.

Damage caused to our forests and its control up to 1918

Energy Technology Data Exchange (ETDEWEB)

Nozicka, J

1963-01-01

Air pollution was mentioned as soon as 1699 by Chr. Lehman, chronicler of Krusne hory and its injurious effects were observed since the thirties of the nineteenth century by brothers Baar on their plot situated in the neighborhood of a manufactory chimney at Kdyne near Klatovy, as well as since 1843 by the surveyor William Rowland in managing the town forest of Pribram in the surroundings of silver works at Brezove hory. The problem of damage caused to our forests by air pollution arose the interest of our foresters 1850, when at the conference of the Bohemian Forestry Union held in Decin Rowland read a paper on air pollution in the area of Pribram and in surroundings of a brick-kiln at Zdiky in the Kaplice region. After 1853, the smoke effects began to be apparent in the Jachymov region, since 1880 in the Ostrava region, since the nineties of the past century in the Sokolovo, Loket, Karlovy Vary, Usti n. L. and Nachod regions and, since the first decade of the present century in the Bilina and Kladno regions. It was found that silver fir, Norway spruce and Scotch pine were the most sensitive species to smoke, whereas European larch proved to be very resistant. Broadleaved species showed also a good growth in the smoke affected areas. Basing on this experience, our foresters tried, therefore, to reduce the injouris smoke effects by growing broadleaved species in those areas. 12 references.

Atmospheric mercury deposition to forests in the eastern USA

International Nuclear Information System (INIS)

Risch, Martin R.; DeWild, John F.; Gay, David A.; Zhang, Leiming; Boyer, Elizabeth W.; Krabbenhoft, David P.

2017-01-01

Atmospheric mercury (Hg) deposition to forests is important because half of the land cover in the eastern USA is forest. Mercury was measured in autumn litterfall and weekly precipitation samples at a total of 27 National Atmospheric Deposition Program (NADP) monitoring sites in deciduous and mixed deciduous-coniferous forests in 16 states in the eastern USA during 2007–2014. These simultaneous, uniform, repeated, annual measurements of forest Hg include the broadest area and longest time frame to date. The autumn litterfall-Hg concentrations and litterfall mass at the study sites each year were combined with annual precipitation-Hg data. Rates of litterfall-Hg deposition were higher than or equal to precipitation-Hg deposition rates in 70% of the annual data, which indicates a substantial contribution from litterfall to total atmospheric-Hg deposition. Annual litterfall-Hg deposition in this study had a median of 11.7 μg per square meter per year (μg/m 2 /yr) and ranged from 2.2 to 23.4 μg/m 2 /yr. It closely matched modeled dry-Hg deposition, based on land cover at selected NADP Hg-monitoring sites. Mean annual atmospheric-Hg deposition at forest study sites exhibited a spatial pattern partly explained by statistical differences among five forest-cover types and related to the mapped density of Hg emissions. Forest canopies apparently recorded changes in atmospheric-Hg concentrations over time because litterfall-Hg concentrations decreased year to year and litterfall-Hg concentrations were significantly higher in 2007–2009 than in 2012–2014. These findings reinforce reported decreases in Hg emissions and atmospheric elemental-Hg concentrations during this same time period. Methylmercury (MeHg) was detected in all litterfall samples at all sites, compared with MeHg detections in less than half the precipitation samples at selected sites during the study. These results indicate MeHg in litterfall is a pathway into the terrestrial food web where it can

The Potential of EnMAP and Sentinel-2 Data for Detecting Drought Stress Phenomena in Deciduous Forest Communities

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Sandra Dotzler

2015-10-01

Full Text Available Given the importance of forest ecosystems, the availability of reliable, spatially explicit information about the site-specific climate sensitivity of tree species is essential for implementing suitable adaptation strategies. In this study, airborne hyperspectral data were used to assess the response of deciduous species (dominated by European beech and Sessile and Pedunculate oak to water stress during a summery dry spell. After masking canopy gaps, shaded crown areas and non-deciduous species, potentially indicative spectral indices, the Photochemical Reflectance Index (PRI, Moisture Stress Index (MSI, Normalized Difference Water Index (NDWI, and Chlorophyll Index (CI, were analyzed with respect to available maps of site-specific soil moisture regimes. PRI provided an important indication of site-specific photosynthetic stress on leaf level in relation to limitations in soil water availability. The CI, MSI and NDWI revealed statistically significant differences in total chlorophyll and water concentration at the canopy level. However, after reducing the canopy effects by normalizing these indices with respect to the structure-sensitive simple ratio (SR vegetation index, it was not yet possible to identify site-specific concentration differences in leaf level at this early stage of the drought. The selected indicators were also tested with simulated EnMAP and Sentinel-2 data (derived from the original airborne data set. While PRI proved to be useful also in the spatial resolution of EnMAP (GSD = 30 m, this was not the case with Sentinel-2, owing to the lack of adequate spectral bands; the remaining indicators (MSI, CI, SR were also successfully produced with Sentinel-2 data at superior spatial resolution (GSD = 10 m. The study confirms the importance of using earth observation systems for supplementing traditional ecological site classification maps, particularly during dry spells and heat waves when ecological gradients are increasingly

Retention of available P in acid soils of tropical and subtropical evergreen broad-leaved forests

Institute of Scientific and Technical Information of China (English)

CHEN Jianhui; ZOU Xiaoming; YANG Xiaodong

2007-01-01

Precipitation of mineral phosphate is often recognized as a factor of limiting the availability of P in acidic soils of tropical and subtropical forests.For this paper,we studied the extractable P pools and their transformation rates in soils of a tropical evergreen forest at Xishuangbanna and a subtropical montane wet forest at the Ailao Mountains in order to understand the biogeochemical processes regulating P availability in acidic soils.The two forests differ in forest humus layer;it is deep in the Ailao forest while little is present in the Xishuangbanna forest.The extractable P pools by resin and sodium-bicarbonate decreased when soil organic carbon content was reduced.The lowest levels of extractable P pools occurred in the surface (0-10 era) mineral soils of the Xishuangbanna forest.However,microbial P in the mineral soil of the Xishuangbauna forest was twice that in the Ailao forest.Potential rates of microbial P immobilization were greater than those of organic P mineralization in mineral soils for both forests.We suggest that microbial P immobilization plays an essential role in avoiding mineral P precipitation and retaining available P of plant in tropical acidic soils,whereas both floor mass accumulation and microbial P immobilization function benefit retaining plant available P in subtropical montane wet forests.

Measuring and Modeling the Effects of Alternate Post-Fire Successional Trajectories on Boreal Forest Carbon Dynamics

Science.gov (United States)

Loranty, M. M.; Goetz, S. J.; Mack, M. C.; Alexander, H. D.; Beck, P. S.

2011-12-01

High latitude ecosystems are experiencing amplified climate warming, and recent evidence suggests concurrent intensification of fire disturbance regimes. In central Alaskan boreal forests, severe burns consume more of the soil organic layer, resulting in increased establishment of deciduous seedlings and altered post-fire stand composition with increased deciduous dominance. Quantifying differences in ecosystem carbon (C) dynamics between forest successional trajectories in response to burn severity is essential for understanding potential changes in regional or global feedbacks between boreal forests and climate. We used the Biome BioGeochemical Cycling model (Biome-BGC) to quantify differences in C stocks and fluxes associated with alternate post-fire successional trajectories related to fire severity. A version of Biome-BGC that allows alternate competing vegetation types was calibrated against a series of aboveground biomass observations from chronosequences of stands with differing post-fire successional trajectories characterized by the proportion of deciduous biomass. The model was able to reproduce observed patterns of biomass accumulation after fire, with stands dominated by deciduous species sequestering more C at a faster rate than stands dominated by conifers. Modeled C fluxes suggest that stands dominated by deciduous species are a stronger sink of atmospheric C soon after disturbance than coniferous stands. These results agree with the few available C flux observations. We use a historic database in conjunction with a map of deciduous canopy cover to explore the consequences of ongoing and potential future changes in the fire regime on central Alaskan C balance.

Structural Relationships Of Selected Tree Species at Several Mid-Latitude Deciduous Forest Sites in Virginia

Science.gov (United States)

1999-09-01

are included in the deciduous analyses. They are mockernut hickory { Carya tomentosa), American elm {Ulmus americana), pecan { Carya illinoensis ), and...alba, white ash (Fraxinus americana), and pecan ( Carya illinoensis ). A number of these trees have plaques indicating the dates of planting (late 1700s

Ectopic decidual reaction mimicking inguinal lymphoma on ultrasound

DEFF Research Database (Denmark)

Lorentzen, C.; Prangsgaard, Tina; Lorentzen, Torben

2014-01-01

Ectopic decidual reaction has been described in various intraperitoneal locations. We present a case of unusual ectopic decidual reaction in the groin mimicking inguinal lymphoma on ultrasound in a pregnant woman. This case contributes evidence illustrating the variability of the clinical...... presentation of ectopic decidual reaction....

Dispersal limitation drives successional pathways in Central Siberian forests under current and intensified fire regimes.

Science.gov (United States)

Tautenhahn, Susanne; Lichstein, Jeremy W; Jung, Martin; Kattge, Jens; Bohlman, Stephanie A; Heilmeier, Hermann; Prokushkin, Anatoly; Kahl, Anja; Wirth, Christian

2016-06-01

Fire is a primary driver of boreal forest dynamics. Intensifying fire regimes due to climate change may cause a shift in boreal forest composition toward reduced dominance of conifers and greater abundance of deciduous hardwoods, with potential biogeochemical and biophysical feedbacks to regional and global climate. This shift has already been observed in some North American boreal forests and has been attributed to changes in site conditions. However, it is unknown if the mechanisms controlling fire-induced changes in deciduous hardwood cover are similar among different boreal forests, which differ in the ecological traits of the dominant tree species. To better understand the consequences of intensifying fire regimes in boreal forests, we studied postfire regeneration in five burns in the Central Siberian dark taiga, a vast but poorly studied boreal region. We combined field measurements, dendrochronological analysis, and seed-source maps derived from high-resolution satellite images to quantify the importance of site conditions (e.g., organic layer depth) vs. seed availability in shaping postfire regeneration. We show that dispersal limitation of evergreen conifers was the main factor determining postfire regeneration composition and density. Site conditions had significant but weaker effects. We used information on postfire regeneration to develop a classification scheme for successional pathways, representing the dominance of deciduous hardwoods vs. evergreen conifers at different successional stages. We estimated the spatial distribution of different successional pathways under alternative fire regime scenarios. Under intensified fire regimes, dispersal limitation of evergreen conifers is predicted to become more severe, primarily due to reduced abundance of surviving seed sources within burned areas. Increased dispersal limitation of evergreen conifers, in turn, is predicted to increase the prevalence of successional pathways dominated by deciduous hardwoods

Environmental variables and tree population structures in deciduous forests of central Brazil with different levels of logging

Directory of Open Access Journals (Sweden)

Daniel Luis Mascia Vieira

2008-04-01

Full Text Available Population structures of six tree species in three fragments of intact seasonal deciduous forest and three fragments disturbed by logging were studied in the northeastern Goiás. Forty random 400 m² plots were allocated in each fragment to survey plant population structures, number of stumps, cattle feces, burnt logs, and canopy openness. Soil cover by life forms was estimated in 1m² sub-plots. Lianas were abundant in intermediately logged fragments and invasive herbs in the most disturbed fragment. Cattle avoided dense herbaceous strata, such as liana tangles. Cavanillesia arborea, Eugenia dysenterica and Swartzia multijuga trees occurred at very low densities in all the fragments and their seedlings were practically absent, which might endanger their future populations in these fragments. Myracrodruon urundeuva, Tabebuia impetiginosa and Astronium fraxinifolium, the most logged species, had high density of seedlings in all the fragments. However, the highest density of saplings and juvenile individuals occurred in the most disturbed fragment.As estruturas populacionais de seis espécies de árvores foram estudadas em três fragmentos de floresta estacional decidual intactos e três fragmentos impactados pela exploração seletiva de madeira no nordeste goiano. Quarenta parcelas de 400m² foram estabelecidas em cada fragmento para a amostragem de populações, número de tocos, fezes de gado, troncos queimados e abertura de dossel. A cobertura do solo por formas de vida foi estimada em sub-parcelas de 1m². Lianas foram mais abundantes em fragmentos com perturbação intermediária, enquanto herbáceas invasoras no fragmento mais perturbado. Cavanillesia arborea, Eugenia dysenterica e Swartzia multijuga ocorreram em densidades muito baixas em todos os fragmentos e plântulas foram praticamente ausentes, o que pode ameaçar o futuro de suas populações. Myracrodruon urundeuva, Tabebuia impetiginosa e Astronium fraxinifolium, as espécies mais

An economic valuation of the recreational benefits associated with nature-based forest management practices

DEFF Research Database (Denmark)

Nielsen, Anders Busse; Olsen, Søren Bøye; Lundhede, Thomas Hedemark

2007-01-01

The presented study aimed at identifying and assessing public preferences for variations in tree species composition, tree height structure, and presence of dead trees left for natural decay – forest characteristics which are likely to be affected when subjecting stands to nature-based forest...... of the mentioned three forest characteristics. The highest WTP (1939 DKK, approx. 262 EUR) was found for a scenario of replacing the baseline case stand of even-aged conifers with no dead trees left for natural decay with a mixture of conifers and broadleaves of varying heights, and leaving a few dead trees...

Satellite derived forest phenology and its relation with nephropathia epidemica in Belgium.

Science.gov (United States)

Barrios, José Miguel; Verstraeten, Willem W; Maes, Piet; Clement, Jan; Aerts, Jean-Marie; Haredasht, Sara Amirpour; Wambacq, Julie; Lagrou, Katrien; Ducoffre, Geneviève; Van Ranst, Marc; Berckmans, Daniel; Coppin, Pol

2010-06-01

The connection between nephropathia epidemica (NE) and vegetation dynamics has been emphasized in recent studies. Changing climate has been suggested as a triggering factor of recently observed epidemiologic peaks in reported NE cases. We have investigated whether there is a connection between the NE occurrence pattern in Belgium and specific trends in remotely sensed phenology parameters of broad-leaved forests. The analysis of time series of the MODIS Enhanced Vegetation Index revealed that changes in forest phenology, considered in literature as an effect of climate change, may affect the mechanics of NE transmission.

Patterns and Drivers of Tree Mortality in Iberian Forests: Climatic Effects Are Modified by Competition

Science.gov (United States)

Ruiz-Benito, Paloma; Lines, Emily R.; Gómez-Aparicio, Lorena; Zavala, Miguel A.; Coomes, David A.

2013-01-01

Tree mortality is a key process underlying forest dynamics and community assembly. Understanding how tree mortality is driven by simultaneous drivers is needed to evaluate potential effects of climate change on forest composition. Using repeat-measure information from c. 400,000 trees from the Spanish Forest Inventory, we quantified the relative importance of tree size, competition, climate and edaphic conditions on tree mortality of 11 species, and explored the combined effect of climate and competition. Tree mortality was affected by all of these multiple drivers, especially tree size and asymmetric competition, and strong interactions between climate and competition were found. All species showed L-shaped mortality patterns (i.e. showed decreasing mortality with tree size), but pines were more sensitive to asymmetric competition than broadleaved species. Among climatic variables, the negative effect of temperature on tree mortality was much larger than the effect of precipitation. Moreover, the effect of climate (mean annual temperature and annual precipitation) on tree mortality was aggravated at high competition levels for all species, but especially for broadleaved species. The significant interaction between climate and competition on tree mortality indicated that global change in Mediterranean regions, causing hotter and drier conditions and denser stands, could lead to profound effects on forest structure and composition. Therefore, to evaluate the potential effects of climatic change on tree mortality, forest structure must be considered, since two systems of similar composition but different structure could radically differ in their response to climatic conditions. PMID:23451096

Ecology of Missouri Forests. Instructional Unit. Conservation Education Series.

Science.gov (United States)

Jackson, Jim

This unit is designed to help science, social studies, vocational agriculture, and other teachers incorporate forest ecology concepts into their subject matter. The unit includes: (1) topic outline; (2) unit objectives; (3) background information on climate and soils, levels of a deciduous forest, age classes, food and energy relationships, forest…

Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S.

Science.gov (United States)

Hadley, J. L.; Kuzeja, P.; Mulcahy, T.; Singh, S.

2008-12-01

Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S. Julian Hadley, Paul Kuzeja, Safina Singh and Thomas Mulcahy Transfers of water vapor from terrestrial ecosystems to the atmosphere affect regional hydrology, weather and climate over short time scales, and forest-atmosphere CO2 exchange affects global climate over long timescales. To better understand these effects for forests dominated by two very different tree species, we measured forest-atmosphere water vapor and CO2 transfers by the eddy flux technique to at two sites in central Massachusetts USA for three years. Average annual evapotranspiration (ET) for a young deciduous forest dominated by red oak (Quercus rubra L., the most abundant tree species in the area), was about 430 mm or 25 percent greater than for a coniferous forest dominated by 100 to 230 year old eastern hemlock (Tsuga canadensis L.). The difference in ET was most pronounced in July and August when the deciduous forest lost about 50 percent more water by ET in the average year (192 mm for oak forest versus 130 mm for hemlock). These data indicate that if deciduous trees with similar physiology to red oak replace hemlocks, summertime ET will increase while summer streamflow, soil water content and the extent of year- round wetlands will decrease. Increased summertime ET should also lead to slightly higher regional atmospheric humidity and precipitation. Hemlock-to-deciduous forest conversion has occurred from North Carolina to southern New England and is continuing northward as a lethal insect pest, the hemlock woolly adelgid (Adelges tsugae Annand) continues to kill hemlocks. Average annual carbon storage for the old hemlock forest in our study was about 3.3 Mg C/ha, nearly equal to the average for the deciduous forest, 3.5 Mg C/ha. This calls into question ecological theory that predicts large declines in the rate of carbon uptake for old forests, and

Model of plutonium dynamics in a deciduous forest ecosystem

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Gardner, R.H.; Dahlman, R.C.

1980-01-01

A linear compartment model with donor-controlled flows between compartments was designed to describe and simulate the behavior of plutonium ( 239 240 Pu) in a contaminated forest ecosystem at Oak Ridge, TN. At steady states predicted by the model, less than 0.25% of the plutonium in the ecosystem resides in biota. Soil is the major repository of plutonium in the forest, and exchanges of plutonium between soil and litter or soil and tree roots were dominant transfers affecting the ecosystem distribution of plutonium. Variation in predicted steady-state amounts of plutonium in the forest, given variability in the model parameters, indicates that our ability to develop models of plutonium transport in ecosystems should improve with greater precision in data from natural environments and a better understanding of sources of variation in plutonium data

Influence of moisture conditions and mineralization of soil solution on structure of litter macrofauna of the deciduous forests of Ukraine steppe zone

Directory of Open Access Journals (Sweden)

V. V. Brygadyrenko

2015-02-01

Full Text Available The accounting of litter mesofauna was carried out in the territory of Dnipropetrovsk, Zaporizhzhya, Nikolaev,Donetsk regions of Ukrainein the natural forest ecosystems in 2001–2014. 339 forest ecosystems were surveyed; xeromesophilic conditions of moistening were characteristic for 47 trial sites, mesophilic conditions – for 99 sites, hygro-mesophilic conditions – for 50 sites, meso-hygrophilic conditions – for 89 sites, hygrophilic conditions – for 54 sites; trophotope C was represented by 35 trial sites, Dc – by 44, Dac – by 76, Dn – by 128, De – by 37, E – by 19 forest ecosystems, accordingly. The relative number of saprophages reaches maximum values in hygro-mesophilic, meso-hygrophilic and hygrophilic conditions, and minimum values – in mesophilic conditions of moistening. The share of rare species is maximum in hygro-mesophilic conditions of moistening. The minimum quantity of mass species is also observed in conditions of hygro-mesophilic and meso-hygrophilic deciduous forests. With the growth of moistening of the soil, quantity of species of Carabidae, Formicidae and other dominant families remains without significant changes. The relative number of Formicidae is maximum in xeromesophilic and mesophilic conditions of soil moistening. In these hygrotopes, as well as in hygro-mesophilic conditions of moistening the Julidae numbers are maximum. The Isopoda percent in mesofauna significantly grows in meso-hygrophilic and hygrophilic conditions of moistening. The share of other dominant taxonomical groups in the structure of litter mesofauna remains without significant changes in numbers. In the majority of the analysed hygrotopes 7–8 families are withing the structure of dominants. In the conditions of salinization (trophotopes De and E, and also on light sandy loam soils, the numbers of litter mesofauna decrease. Share of saprophages is minimum in trophotopes Dc and E, while it increases in trophotopes C, Dac, Dn

Environmental measures in forest. Realistic measures for counteracting negative effects of acid precipitation in forest; Miljoetiltak i skog. Realistiske tiltak for aa motvirke negative effekter av sur nedboer i skog

Energy Technology Data Exchange (ETDEWEB)

Nilsen, P [Norsk Inst. for Skogforskning, Aas (Norway)

1996-01-01

The conference paper deals with an Norwegian research programme concerning environmental measures for decreasing the effects of acidification in forest areas. This programme, which lasts in a period of five years, will terminate in 1997. An important part of the programme has been to investigate other types of measures than the ordinary methods of liming and fertilizing. In the course of the programme, there was determined to put the attention to the increased use of broad-leaved trees as an alternative in a coniferous forest. 19 refs., 1 fig.

The Forest, Part 4: Late Summer and Fall

Science.gov (United States)

Johnson, Elfriede Nemetz

1973-01-01

Briefly describes the ecology of a deciduous forest, and suggests activities for observing and appreciating the changes that occur during the Fall. Simple experiments relating to mosses and lichens are outlined. (JR)

Use of the isotope flux ratio approach to investigate the C18O16O and 13CO2 exchange near the floor of a temperate deciduous forest

Directory of Open Access Journals (Sweden)

P. Bartlett

2012-07-01

Full Text Available Stable isotopologues of CO2, such as 13CO2 and C18OO, have been used to study the CO2 exchange between land and atmosphere. The advent of new measuring techniques has allowed near-continuous measurements of stable isotopes in the air. These measurements can be used with micrometeorological techniques, providing new tools to investigate the isotope exchange in ecosystems. The objectives of this study were to evaluate the use of the isotope flux ratio method (IFR near the forest floor of a temperate deciduous forest and to study the temporal dynamics of δ18O of CO2 flux near the forest floor by comparing IFR estimates with estimates of δ18O of net soil CO2 flux provided by an analytical model. Mixing ratios of 12C16O2, 13CO2 and C16O18O were measured within and above a temperate deciduous forest, using the tunable diode laser spectroscopy technique. The half-hourly compositions of the CO2 flux near the forest floor (δ13CF and δ18OF were calculated by IFR and compared with estimates provided by a modified Keeling plot technique (mKP and by a Lagrangian dispersion analysis (WT analysis. The mKP and IFR δ18OF estimates showed good agreement (slope = 1.03 and correlation, R2 = 0.80. The δ13CF estimates from the two methods varied in a narrow range of −32.7 and −23‰; the mean (± SE mKP and IFR δ13CF values were −27.5‰ (±0.2 and −27.3‰ (±0.1, respectively, and were statistically identical (p>0.05. WT analysis and IFR δ18OF estimates showed better correlation (R2 = 0.37 when only turbulent periods (u*>0.6 m s−1 were included in the analysis. The large amount of data captured (~95 % of half-hour periods evaluated for the IFR in comparison with mKP (27 % shows that the former provides new opportunities for studying δ18OF dynamics within forest canopies. Values of δ18OF showed large temporal variation, with values ranging from −31.4‰ (DOY 208 to −11.2‰ (DOY 221. Precipitation events caused substantial variation (~8�

Geospatial monitoring and prioritization of forest fire incidences in Andhra Pradesh, India.

Science.gov (United States)

Manaswini, G; Sudhakar Reddy, C

2015-10-01

Forest fire has been identified as one of the key environmental issue for long-term conservation of biodiversity and has impact on global climate. Spatially multiple observations are necessary for monitoring of forest fires in tropics for understanding conservation efficacy and sustaining biodiversity in protected areas. The present work was carried out to estimate the spatial extent of forest burnt areas and fire frequency using Resourcesat Advanced Wide Field Sensor (AWiFS) data (2009, 2010, 2012, 2013 and 2014) in Andhra Pradesh, India. The spatio-temporal analysis shows that an area of 7514.10 km(2) (29.22% of total forest cover) has been affected by forest fires. Six major forest types are distributed in Andhra Pradesh, i.e. semi-evergreen, moist deciduous, dry deciduous, dry evergreen, thorn and mangroves. Of the total forest burnt area, dry deciduous forests account for >75%. District-wise analysis shows that Kurnool, Prakasam and Cuddapah have shown >100 km(2) of burnt area every year. The total forest burnt area estimate covering protected areas ranges between 6.9 and 22.3% during the study period. Spatial burnt area analysis for protected areas in 2014 indicates 37.2% of fire incidences in the Nagarjunasagar Srisailam Tiger Reserve followed by 20.2 % in the Sri Lankamalleswara Wildlife Sanctuary, 20.1% in the Sri Venkateswara Wildlife Sanctuary and 17.4% in the Gundla Brahmeswaram Wildlife Sanctuary. The analysis of cumulative fire occurrences from 2009 to 2014 has helped in delineation of conservation priority hotspots using a spatial grid cell approach. Conservation priority hotspots I and II are distributed in major parts of study area including protected areas of the Nagarjunasagar Srisailam Tiger Reserve and Gundla Brahmeswaram Wildlife Sanctuary. The spatial database generated will be useful in studies related to influence of fires on species adaptability, ecological damage assessment and conservation planning.

SELECTIVE FORAGING ON WOODY SPECIES BY THE BEAVER CASTOR FIBER, AND ITS IMPACT ON A RIPARIAN WILLOW FOREST

NARCIS (Netherlands)

NOLET, BA; HOEKSTRA, A; OTTENHEIM, MM

1994-01-01

Beavers were re-introduced in the Biesbosch, The Netherlands, a wood dominated by willows Salix spp. Conservationists expected that herbivory by beavers would enhance succession to a mixed broad-leaved forest. Willows formed the staple food of the beavers, but they removed only 1.4% of the standing

Influence of different forest system management practices on leaf litter decomposition rates, nutrient dynamics and the activity of ligninolytic enzymes: a case study from central European forests.

Science.gov (United States)

Purahong, Witoon; Kapturska, Danuta; Pecyna, Marek J; Schulz, Elke; Schloter, Michael; Buscot, François; Hofrichter, Martin; Krüger, Dirk

2014-01-01

Leaf litter decomposition is the key ecological process that determines the sustainability of managed forest ecosystems, however very few studies hitherto have investigated this process with respect to silvicultural management practices. The aims of the present study were to investigate the effects of forest management practices on leaf litter decomposition rates, nutrient dynamics (C, N, Mg, K, Ca, P) and the activity of ligninolytic enzymes. We approached these questions using a 473 day long litterbag experiment. We found that age-class beech and spruce forests (high forest management intensity) had significantly higher decomposition rates and nutrient release (most nutrients) than unmanaged deciduous forest reserves (Pforest management (low forest management intensity) exhibited no significant differences in litter decomposition rate, C release, lignin decomposition, and C/N, lignin/N and ligninolytic enzyme patterns compared to the unmanaged deciduous forest reserves, but most nutrient dynamics examined in this study were significantly faster under such near-to-nature forest management practices. Analyzing the activities of ligninolytic enzymes provided evidence that different forest system management practices affect litter decomposition by changing microbial enzyme activities, at least over the investigated time frame of 473 days (laccase, Pforest system management practices can significantly affect important ecological processes and services such as decomposition and nutrient cycling.

The arboreal component of a dry forest in Northeastern Brazil

OpenAIRE

Rodal,M. J. N.; Nascimento,L. M.

2006-01-01

The dry forests of northeastern Brazil are found near the coastal zone and on low, isolated mountains inland amid semi-arid vegetation. The floristic composition of these dry montane forests, as well as their relationship to humid forests (Atlantic forest sensu stricto) and to the deciduous thorn woodlands (Caatinga sensu stricto) of the Brazilian northeast are not yet well known. This paper sought to determine if the arboreal plants in a dry forest growing on a low mountain in the semi-arid ...

Leaf litter and roots as sources of mineral soil organic matter in temperate deciduous forest with and without earthworms

Science.gov (United States)

Fahey, T.; Yavitt, J. B.

2012-12-01

We labeled sugar maple trees with 13C to quantify the separate contributions of decaying leaf litter and root turnover/rhizosphere C flux to mineral soil organic matter (SOM). Labeled leaf litter was applied to forest plots with and without earthworms and recovery of the label in SOM was quantified over three years. In parallel, label recovery was quantified in soils from the labeling chambers where all label was supplied by belowground C flux. In the absence of earthworms about half of the label added as leaf litter remained in the surface organic horizons after three years, with about 3% recovered in mineral SOM. The label was most enriched on silt + clay surfaces, representing precipitation of DOC derived from litter. Earthworms mixed nearly all the leaf litter into mineral soil within one year, and after two years the label was most enriched in particulate organic matter held within soil aggregates produced by worms. After three years 15-20% of the added label was recovered in mineral SOM. In the labeling chambers over 75% of belowground C allocation (BCA) was used in root and rhizosphere respiration in the first year after labeling. We recovered only 3.8% of estimated BCA in SOM after 3 years; however, expressed as a proportion of fine root production plus rhizosphere C flux, this value is 15.4%, comparable to that for leaf litter in the presence of earthworms. In conclusion, both roots and leaf litter contribute significantly to the formation of stabilized mineral SOM in temperate deciduous forests, and this process is profoundly altered by the invasion of lumbricid earthworms.

Effects of elevated nitrogen deposition on soil microbial biomass carbon in major subtropical forests of southern China

Institute of Scientific and Technical Information of China (English)

Hui WANG; Jiangming MO; Xiankai LU; Jinghua XUE; Jiong LI; Yunting FANG

2009-01-01

The effects of elevated nitrogen deposition on soil microbial biomass carbon (C) and extractable dissolved organic carbon (DOC) in three types of forest of southern China were studied in November, 2004 and June, 2006. Plots were established in a pine forest (PF), a mixed pine and broad-leaved forest (MF) and monsoon evergreen broad-leaved forest (MEBF) in the Dinghushan Nature Reserve. Nitrogen treatments included a control (no N addition), low N (50 kg N/(hm2.a)), medium N (100 kg N/ (hm2. a)) and high N (150 kg N/(hm2. a)). Microbial biomass C and extractable DOC were determined using a chloro-form fumigation-extraction method. Results indicate that microbial biomass C and extractable DOC were higher in June, 2006 than in November, 2004 and higher in the MEBF than in the PF or the MF. The response of soil microbial biomass C and extractable DOC to nitrogen deposition varied depending on the forest type and the level of nitrogen treatment. In the PF or MF forests, no significantly different effects of nitrogen addition were found on soil microbial biomass C and extractable DOC. In the MEBF, however, the soil microbial biomass C generally decreased with increased nitrogen levels and high nitrogen addition significantly reduced soil microbial biomass C. The response of soil extractable DOC to added nitrogen in the MEBF shows the opposite trend to soil microbial biomass C. These results suggest that nitrogen deposition may increase the accumulation of soil organic carbon in the MEBF in the study region.

Spatial and temporal trends in distribution of forest fires in Central and Eastern Europe

Science.gov (United States)

Ryszard Szczygieł; Barbara Ubysz; Tomasz. Zawiła-Niedźwiecki

2009-01-01

Forest in Central and Eastern Europe (CEE) covers 56,285,000 ha (5% of European total forested area). Forest cover in CEE makes 30% of land use. Almost 50% of the forest under study is formed by coniferous species and only 30% by deciduous ones. Forest younger than 60 years old grows on 57% of that area. These factors, together with climate conditions cause that on the...

Satellite Derived Forest Phenology and Its Relation with Nephropathia Epidemica in Belgium

Directory of Open Access Journals (Sweden)

José Miguel Barrios

2010-06-01

Full Text Available The connection between nephropathia epidemica (NE and vegetation dynamics has been emphasized in recent studies. Changing climate has been suggested as a triggering factor of recently observed epidemiologic peaks in reported NE cases. We have investigated whether there is a connection between the NE occurrence pattern in Belgium and specific trends in remotely sensed phenology parameters of broad-leaved forests. The analysis of time series of the MODIS Enhanced Vegetation Index revealed that changes in forest phenology, considered in literature as an effect of climate change, may affect the mechanics of NE transmission.

Upscaling from leaf to canopy chlorophyll/carotenoid pigment based vegetation indices reveal phenology of photosynthesis in temperate evergreen and deciduous trees

Science.gov (United States)

Wong, C. Y.; Bhathena, Y.; Arain, M. A.; Ensminger, I.

2017-12-01

Optically derived vegetation indices have been developed to provide information about plant status including photosynthetic activity. They reflect changes in leaf pigments, which vary seasonally in pigment composition, enabling them to be used as a proxy of photosynthetic phenology. Important pigments in photosynthetic activity are carotenoids and chlorophylls, which are associated with light harvesting and energy dissipation. In temperate forests, which consist of deciduous and evergreen trees, there are difficulties resolving evergreen phenology using the most widely used index, the normalized difference vegetation index (NDVI). NDVI works well in deciduous trees, which exhibit a "visible" phenological process of leaf growth in the spring, and leaf senescence and abscission in the autumn. Evergreen conifers stay green year-round and utilize "invisible" changes of overwintering pigment composition that NDVI cannot resolve, so carotenoid pigment sensitive vegetation indices have been suggested for evergreens. The aim of this study was to evaluate carotenoid based vegetation indices over the chlorophyll sensitive NDVI. For this purpose, we evaluated the greenness index, NDVI, and carotenoid pigment sensitive indices: photochemical reflectance index (PRI) and chlorophyll/carotenoid index (CCI) in red maple, white oak and eastern white pine for two years. We also measured leaf gas exchange and pigment concentrations. We observed that NDVI correlated with photosynthetic activity in deciduous trees, whereas PRI and CCI correlated with photosynthesis across both evergreen and deciduous trees. This pattern was consistent, upscaling from leaf- to canopy-scales indicating that the mechanisms involved in winter acclimation can be resolved at larger spatial scales. PRI and CCI detected seasonal changes in carotenoids and chlorophylls linked to photoprotection and are suitable as a proxy of photosynthetic activity. These findings have implications to improve our use and

Litterfall in the hardwood forest of a minor alluvial-floodplain

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Calvin E. Meier; John A. Stanturf; Emile S. Gardiner

2006-01-01

within mature deciduous forests, annual development of foliar biomass is a major component of aboveground net primary production and nutrient demand. As litterfall, this same foliage becomes a dominant annual transfer of biomass and nutrients to the detritus pathway. We report litterfall transfers of a mature bottomland hardwood forest in a minor alluvial-floodplain...

Response of Quercus velutina growth and water use efficiency to climate variability and nitrogen fertilization in a temperate deciduous forest in the northeastern USA.

Science.gov (United States)

Jennings, Katie A; Guerrieri, Rossella; Vadeboncoeur, Matthew A; Asbjornsen, Heidi

2016-04-01

Nitrogen (N) deposition and changing climate patterns in the northeastern USA can influence forest productivity through effects on plant nutrient relations and water use. This study evaluates the combined effects of N fertilization, climate and rising atmospheric CO2on tree growth and ecophysiology in a temperate deciduous forest. Tree ring widths and stable carbon (δ(13)C) and oxygen (δ(18)O) isotopes were used to assess tree growth (basal area increment, BAI) and intrinsic water use efficiency (iWUE) ofQuercus velutinaLamb., the dominant tree species in a 20+ year N fertilization experiment at Harvard Forest (MA, USA). We found that fertilized trees exhibited a pronounced and sustained growth enhancement relative to control trees, with the low- and high-N treatments responding similarly. All treatments exhibited improved iWUE over the study period (1984-2011). Intrinsic water use efficiency trends in the control trees were primarily driven by changes in stomatal conductance, while a stimulation in photosynthesis, supported by an increase in foliar %N, contributed to enhancing iWUE in fertilized trees. All treatments were predominantly influenced by growing season vapor pressure deficit (VPD), with BAI responding most strongly to early season VPD and iWUE responding most strongly to late season VPD. Nitrogen fertilization increasedQ. velutinasensitivity to July temperature and precipitation. Combined, these results suggest that ambient N deposition in N-limited northeastern US forests has enhanced tree growth over the past 30 years, while rising ambient CO2has improved iWUE, with N fertilization and CO2having synergistic effects on iWUE. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Phytogeographical patterns of dry forests sensu stricto in northern Minas Gerais State, Brazil.

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Arruda, Daniel M; Ferreira-Júnior, Walnir G; Duque-Brasil, Reinaldo; Schaefer, Carlos E R

2013-01-01

The Deciduous Complex that occurs in northern Minas Gerais State, Brazil, raises questions about the floristic affinities of these formations in relation to neighboring phytogeographical domains. Little is known about the identity of the seasonal forest formations that comprise this complex, or about its relationships to abiotic components, such as soils, topography and climate. This study aimed to recognize the patterns of floristic similarity of all studied fragments of dry forest of northern Minas Gerais with soil and climate attributes, based on the available database. Cluster analysis indicated the existence of two floristic groups that had clear associations with either the Koppen's BSh (semi-arid) or Aw (seasonal tropical) climates. Likewise, the subdivisions of these groups showed clear associations with the dominant soil classes in the region. The Red-Yellow Latosol is the dominant soil classes in the BSh climatic domain, seconded by alluvial areas associated with Fluvic Neosols. The Aw domain comprised a much varied set of soils: Nitosols, Argisols, Cambisols and Litholic Neosols, most derived from the Bambuí limestone/slate formation. The ecotonal nature of northern Minas Gerais State provides a complex interaction between the flora of neighboring phytogeographical domains. This, allied to pedogeomorphological factors, allowed a better understanding of the effects of late Quaternary climate changes for the Deciduous Complex evolution. We conclude that the Latosols under present-day semi-arid climates (BSh) are relicts of former wetter climates, during which humid forest (semideciduous) expansion took place. Later, these semideciduous forests were subjected to a much drier climate, when selection for deciduousness led to the present-days Deciduous Complex scenario.

Forest Classification Based on Forest texture in Northwest Yunnan Province

Science.gov (United States)

Wang, Jinliang; Gao, Yan; Wang, Xiaohua; Fu, Lei

2014-03-01

Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5 Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19 and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21.

Forest Classification Based on Forest texture in Northwest Yunnan Province

International Nuclear Information System (INIS)

Wang, Jinliang; Gao, Yan; Fu, Lei; Wang, Xiaohua

2014-01-01

Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5; Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19; and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21

Seedling growth and biomass allocation in relation to leaf habit and shade tolerance among 10 temperate tree species.

Science.gov (United States)

Modrzyński, Jerzy; Chmura, Daniel J; Tjoelker, Mark G

2015-08-01

Initial growth of germinated seeds is an important life history stage, critical for establishment and succession in forests. Important questions remain regarding the differences among species in early growth potential arising from shade tolerance. In addition, the role of leaf habit in shaping relationships underlying shade tolerance-related differences in seedling growth remains unresolved. In this study we examined variation in morphological and physiological traits among seedlings of 10 forest tree species of the European temperate zone varying in shade tolerance and leaf habit (broadleaved winter-deciduous species vs needle-leaved conifers) during a 10-week period. Seeds were germinated and grown in a controlled environment simulating an intermediate forest understory light environment to resolve species differences in initial growth and biomass allocation. In the high-resource experimental conditions during the study, seedlings increased biomass allocation to roots at the cost of leaf biomass independent of shade tolerance and leaf habit. Strong correlations between relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf mass fraction (LMF) indicate that physiology and biomass allocation were equally important determinants of RGR as plant structure and leaf morphology among these species. Our findings highlight the importance of seed mass- and seed size-related root morphology (specific root length-SRL) for shade tolerance during early ontogeny. Leaf and plant morphology (SLA, LAR) were more successful in explaining variation among species due to leaf habit than shade tolerance. In both broadleaves and conifers, shade-tolerant species had lower SRL and greater allocation of biomass to stems (stem mass fraction). Light-seeded shade-intolerant species with greater SRL had greater RGR in both leaf habit groups. However, the greatest plant mass was accumulated in the group of heavy-seeded shade

On the vertical distribution of bees in a temperate deciduous forest

Science.gov (United States)

Michael Ulyshen; Villa Soon; James Hanula

2010-01-01

1. Despite a growing interest in forest canopy biology, very few studies have examined the vertical distribution of forest bees. In this study, bees were sampled using 12 pairs of flight-intercept traps suspended in the canopy (‡15 m) and near the ground (0.5 m) in a bottomland hardwood forest in the southeastern United States. 2. In total, 6653 bees from 5 families...

Leaching of nitrate from temperate forests - effects of air pollution and forest management

DEFF Research Database (Denmark)

Gundersen, Per; Schmidt, Inger Kappel; Raulund-Rasmussen, Karsten

2006-01-01

deposition (> 8-10 kg ha(-1) a(-1)). We synthesized the current understanding of factors controlling N leaching in relation to three primary causes of N cycle disruption: (i) Increased N input (air pollution, fertilization, N-2 fixing plants). In European forests, elevated N deposition explains approximately...... half of the variability in N leaching, some of the remaining variability could be explained by differences in N availability or "N status". For coniferous forests, needle N content above 1.4% and (or) forest floor C:N ratio lower than 25 were thresholds for elevated nitrate leaching. At adjacent sites...... conifer forests receive higher N deposition and exhibit higher nitrate loss than deciduous forests; an exception is alder that shows substantial nitrate leaching through N fixation input. Fertilization with N poses limited risk to water quality, when applied to N-limited forests. (ii) Reduced plant uptake...

Growth and yield model application in tropical rain forest management

Science.gov (United States)

James Atta-Boateng; John W., Jr. Moser

2000-01-01

Analytical tools are needed to evaluate the impact of management policies on the sustainable use of rain forest. Optimal decisions concerning the level of management inputs require accurate predictions of output at all relevant input levels. Using growth data from 40 l-hectare permanent plots obtained from the semi-deciduous forest of Ghana, a system of 77 differential...

Evaluation and prediction of shrub cover in coastal Oregon forests (USA)

Science.gov (United States)

Becky K. Kerns; Janet L. Ohmann

2004-01-01

We used data from regional forest inventories and research programs, coupled with mapped climatic and topographic information, to explore relationships and develop multiple linear regression (MLR) and regression tree models for total and deciduous shrub cover in the Oregon coastal province. Results from both types of models indicate that forest structure variables were...

Vegetation carbon sequestration in Chinese forests from 2010 to 2050.

Science.gov (United States)

He, Nianpeng; Wen, Ding; Zhu, Jianxing; Tang, Xuli; Xu, Li; Zhang, Li; Hu, Huifeng; Huang, Mei; Yu, Guirui

2017-04-01

Forests store a large part of the terrestrial vegetation carbon (C) and have high C sequestration potential. Here, we developed a new forest C sequestration (FCS) model based on the secondary succession theory, to estimate vegetation C sequestration capacity in China's forest vegetation. The model used the field measurement data of 3161 forest plots and three future climate scenarios. The results showed that logistic equations provided a good fit for vegetation biomass with forest age in natural and planted forests. The FCS model has been verified with forest biomass data, and model uncertainty is discussed. The increment of vegetation C storage in China's forest vegetation from 2010 to 2050 was estimated as 13.92 Pg C, while the average vegetation C sequestration rate was 0.34 Pg C yr -1 with a 95% confidence interval of 0.28-0.42 Pg C yr -1 , which differed significantly between forest types. The largest contributor to the increment was deciduous broadleaf forest (37.8%), while the smallest was deciduous needleleaf forest (2.7%). The vegetation C sequestration rate might reach its maximum around 2020, although vegetation C storage increases continually. It is estimated that vegetation C sequestration might offset 6-8% of China's future emissions. Furthermore, there was a significant negative relationship between vegetation C sequestration rate and C emission rate in different provinces of China, suggesting that developed provinces might need to compensate for undeveloped provinces through C trade. Our findings will provide valuable guidelines to policymakers for designing afforestation strategies and forest C trade in China. © 2016 John Wiley & Sons Ltd.

Climate change implications of shifting forest management strategy in a boreal forest ecosystem of Norway.

Science.gov (United States)

Bright, Ryan M; Antón-Fernández, Clara; Astrup, Rasmus; Cherubini, Francesco; Kvalevåg, Maria; Strømman, Anders H

2014-02-01

Empirical models alongside remotely sensed and station measured meteorological observations are employed to investigate both the local and global direct climate change impacts of alternative forest management strategies within a boreal ecosystem of eastern Norway. Stand-level analysis is firstly executed to attribute differences in daily, seasonal, and annual mean surface temperatures to differences in surface intrinsic biophysical properties across conifer, deciduous, and clear-cut sites. Relative to a conifer site, a slight local cooling of −0.13 °C at a deciduous site and −0.25 °C at a clear-cut site were observed over a 6-year period, which were mostly attributed to a higher albedo throughout the year. When monthly mean albedo trajectories over the entire managed forest landscape were taken into consideration, we found that strategies promoting natural regeneration of coniferous sites with native deciduous species led to substantial global direct climate cooling benefits relative to those maintaining current silviculture regimes – despite predicted long-term regional warming feedbacks and a reduced albedo in spring and autumn months. The magnitude and duration of the cooling benefit depended largely on whether management strategies jointly promoted an enhanced material supply over business-as-usual levels. Expressed in terms of an equivalent CO2 emission pulse at the start of the simulation, the net climate response at the end of the 21st century spanned −8 to −159 Tg-CO2-eq., depending on whether near-term harvest levels increased or followed current trends, respectively. This magnitude equates to approximately −20 to −300% of Norway's annual domestic (production) emission impact. Our analysis supports the assertion that a carbon-only focus in the design and implementation of forest management policy in boreal and other climatically similar regions can be counterproductive – and at best – suboptimal if boreal forests are to be used as a

Carbon Sequestration of Caesalpinia platyloba S. Watt (Leguminosae) (Lott 1985) in the Tropical Deciduous Forest

Science.gov (United States)

Diaz-Gustavo, Norma; Martínez-Salvador, Martín; García-Hernández, José Luís; Norzagaray-Campos, Mariano; Luna-González, Antonio; González-Ocampo, Héctor Abelardo

2015-01-01

Caesalpinia platyloba was evaluated as an alternative for the retention of atmospheric carbon and as a feasible and viable economic activity in terms of income for tropical deciduous forest (TDF) peasants in the carbon markets. A total of 110 trees of C. platyloba from plantations and a TDF in the Northwest of Mexico were sampled. Growth (increase in height, diameter, and volume curves) was adjusted to assess their growth. Growth of individuals (height, diameter at breast height [DBH], age, and tree crown cover) was recorded. The Schumacher model (H = β 0 e β1•E-1), by means of the guided curve method, was used to adjust growth models. Information analysis was made through the non-linear procedure with the multivariate secant or false position (DUD) method using the SAS software. Growth and increase models revealed acceptable adjustments (pseudo R2>0.8). C. platyloba reaches >8m of height with 12cm in diameter and 550cm3 of volume, presenting the highest increase at 11 years considered as basal age. Highest significant density of wood was in good quality sites (0.80g•cm-3), with a carbon content (average of 99.15tC•ha-1) at the highest density of 2500 trees•ha-1 (without thinning). Average incomes of US$483.33tC•ha-1 are expected. The profitability values (NPW = US$81,646.65, IRR = 472%, and B/C = 0.82) for C. platyloba make its cultivation a viable and profitable activity, considering a management scheme of the income derived from wood selling and from carbon credits. PMID:25992905

Litter-dwelling arthropod abundance peaks near coarse woody debris in loblolly pine forest of the southeastern United States.

Science.gov (United States)

Michael D. Ulyshen; J.L. Hanula

2009-01-01

Several recent studies have shown that many litter-dwelling arthropod and other invertebrate taxa (e.g., Isopoda, Chilopoda, Diplopoda, Araneae, Pseudo scorpionida, Coleoptera, and Gastropoda) are more numerous near dead wood than away from it in the broad-leaved forests of Europe (Jabin et al. 2004; Topp et al. 2006a, 2006b; Kappes et...

Photoprotection related to xanthophyll cycle pigments in epiphytic orchids acclimated at different light microenvironments in two tropical dry forests of the Yucatan Peninsula, Mexico.

Science.gov (United States)

de la Rosa-Manzano, Edilia; Andrade, José Luis; García-Mendoza, Ernesto; Zotz, Gerhard; Reyes-García, Casandra

2015-12-01

Epiphytic orchids from dry forests of Yucatán show considerable photoprotective plasticity during the dry season, which depends on leaf morphology and host tree deciduousness. Nocturnal retention of antheraxanthin and zeaxanthin was detected for the first time in epiphytic orchids. In tropical dry forests, epiphytes experience dramatic changes in light intensity: photosynthetic photon flux density may be up to an order of magnitude higher in the dry season compared to the wet season. To address the seasonal changes of xanthophyll cycle (XC) pigments and photosynthesis that occur throughout the year, leaves of five epiphytic orchid species were studied during the early dry, dry and wet seasons in a deciduous and a semi-deciduous tropical forests at two vertical strata on the host trees (3.5 and 1.5 m height). Differences in XC pigment concentrations and photosynthesis (maximum quantum efficiency of photosystem II; F v/F m) were larger among seasons than between vertical strata in both forests. Antheraxanthin and zeaxanthin retention reflected the stressful conditions of the epiphytic microhabitat, and it is described here in epiphytes for the first time. During the dry season, both XC pigment concentrations and photosystem II heat dissipation of absorbed energy increased in orchids in the deciduous forest, while F v/F m and nocturnal acidification (ΔH(+)) decreased, clearly as a response to excessive light and drought. Concentrations of XC pigments were higher than those in orchids with similar leaf shape in semi-deciduous forest. There, only Encyclia nematocaulon and Lophiaris oerstedii showed somewhat reduced F v/F m. No changes in ΔH(+) and F v/F m were detected in Cohniella ascendens throughout the year. This species, which commonly grows in forests with less open canopies, showed leaf tilting that diminished light interception. Light conditions in the uppermost parts of the canopy probably limit the distribution of epiphytic orchids and the retention of

Estimation of radioactive 137-cesium transportation by litterfall, stemflow and throughfall in the forests of Fukushima

International Nuclear Information System (INIS)

Endo, Izuki; Ohte, Nobuhito; Iseda, Kohei; Tanoi, Keitaro; Hirose, Atsushi; Kobayashi, Natsuko I.; Murakami, Masashi; Tokuchi, Naoko; Ohashi, Mizue

2015-01-01

Since the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011, large areas of the forests around Fukushima have become highly contaminated by radioactive nuclides. To predict the future dynamics of radioactive cesium ( 137 Cs) in the forest catchment, it is important to measure each component of its movement within the forest. Two years after the accident, we estimated the annual transportation of 137 Cs from the forest canopy to the floor by litterfall, throughfall and stemflow. Seasonal variations in 137 Cs transportation and differences between forests types were also determined. The total amount of 137 Cs transported from the canopy to the floor in two deciduous and cedar plantation forests ranged between 3.9 and 11.0 kBq m −2  year −1 . We also observed that 137 Cs transportation with litterfall increased in the defoliation period, simply because of the increased amount of litterfall. 137 Cs transportation with throughfall and stemflow increased in the rainy season, and 137 Cs flux by litterfall was higher in cedar plantation compared with that of mixed deciduous forest, while the opposite result was obtained for stemflow. - Highlights: • Annual flux of 137 Cs by litterfall, throughfall and stemflow was estimated in two types of forest in Fukushima, Japan. • Annual amount of 137 Cs transportation was 3.9–11.0 kBq m −2 year −1 in two years after the accident. • 137 Cs flux by litterfall was higher in cedar plantation than that of mixed deciduous forest. • 137 Cs transportation with throughfall and stemflow increased in rainy season.

High density of tree-cavities and snags in tropical dry forest of western Mexico raises questions for a latitudinal gradient.

Directory of Open Access Journals (Sweden)

Leopoldo Vázquez

Full Text Available It has been suggested that a latitudinal gradient exists of a low density of snags and high density of naturally-formed tree-cavities in tropical vs. temperate forests, though few cavities may have characteristics suitable for nesting by birds. We determined snag and cavity density, characteristics, and suitability for birds in a tropical dry forest biome of western Mexico, and evaluated whether our data fits the trend of snag and cavity density typically found in tropical moist and wet forests. We established five 0.25-ha transects to survey and measure tree-cavities and snags in each of three vegetation types of deciduous, semi-deciduous, and mono-dominant Piranhea mexicana forest, comprising a total of 3.75 ha. We found a high density of 77 cavities/ha, with 37 cavities suitable for birds/ha, where density, and characteristics of cavities varied significantly among vegetation types. Lowest abundance of cavities occurred in deciduous forest, and these were in smaller trees, at a lower height, and with a narrower entrance diameter. Only 8.6% of cavities were excavated by woodpeckers, and only 11% of cavities were occupied, mainly by arthropods, though 52% of all cavities were unsuitable for birds. We also found a high density of 56 snags/ha, with greatest density in deciduous forest (70 snags/ha, though these were of significantly smaller diameter, and snags of larger diameter were more likely to contain cavities. The Chamela-Cuixmala tropical dry forest had the highest density of snags recorded for any tropical or temperate forest, and while snag density was significantly correlated with mean snag dbh, neither latitude nor mean dbh predicted snag density in ten forest sites. The high spatial aggregation of snag and cavity resources in tropical dry forest may limit their availability, particularly for large-bodied cavity adopters, and highlights the importance of habitat heterogeneity in providing resources for primary and secondary cavity-nesters.

High density of tree-cavities and snags in tropical dry forest of western Mexico raises questions for a latitudinal gradient.

Science.gov (United States)

Vázquez, Leopoldo; Renton, Katherine

2015-01-01

It has been suggested that a latitudinal gradient exists of a low density of snags and high density of naturally-formed tree-cavities in tropical vs. temperate forests, though few cavities may have characteristics suitable for nesting by birds. We determined snag and cavity density, characteristics, and suitability for birds in a tropical dry forest biome of western Mexico, and evaluated whether our data fits the trend of snag and cavity density typically found in tropical moist and wet forests. We established five 0.25-ha transects to survey and measure tree-cavities and snags in each of three vegetation types of deciduous, semi-deciduous, and mono-dominant Piranhea mexicana forest, comprising a total of 3.75 ha. We found a high density of 77 cavities/ha, with 37 cavities suitable for birds/ha, where density, and characteristics of cavities varied significantly among vegetation types. Lowest abundance of cavities occurred in deciduous forest, and these were in smaller trees, at a lower height, and with a narrower entrance diameter. Only 8.6% of cavities were excavated by woodpeckers, and only 11% of cavities were occupied, mainly by arthropods, though 52% of all cavities were unsuitable for birds. We also found a high density of 56 snags/ha, with greatest density in deciduous forest (70 snags/ha), though these were of significantly smaller diameter, and snags of larger diameter were more likely to contain cavities. The Chamela-Cuixmala tropical dry forest had the highest density of snags recorded for any tropical or temperate forest, and while snag density was significantly correlated with mean snag dbh, neither latitude nor mean dbh predicted snag density in ten forest sites. The high spatial aggregation of snag and cavity resources in tropical dry forest may limit their availability, particularly for large-bodied cavity adopters, and highlights the importance of habitat heterogeneity in providing resources for primary and secondary cavity-nesters.

Study on the forest vegetation restoration monitoring using HJ-1A hyperspectral data

International Nuclear Information System (INIS)

Chuan, Zhang; Fawang, Ye; Hongcheng, Liu; Haixia, He

2014-01-01

In this paper, Xunke County was studied using HJ-1A hyperspectral data for monitoring vegetation restoration after forest fires. The pre-processing procedure including data format conversion, image mosaicing and atmospheric correction. Support vector machine classification was used to perform surface feature identification based on the extracted spectral end-members. On that basis, the image area was divided into seven categories and statistical analysis of classification types was performed. The results showed that HJ-1A hyperspectral data had great potential in fine classification of surface features and the accuracy of classification was 91.8%. The mild and severe fire-affected area extraction provided useful reference for disaster recovery monitoring. Furthermore, the distinction between coniferous forest and broadleaved forest can offer useful information for forest fire prevention and early warning to some extent

Light-dependent leaf trait variation in 43 tropical dry forest tree species

NARCIS (Netherlands)

Markesteijn, L.; Poorter, L.; Bongers, F.J.J.M.

2007-01-01

Our understanding of leaf acclimation in relation to irradiance of fully grown or juvenile trees is mainly based on research involving tropical wet forest species. We studied sun¿shade plasticity of 24 leaf traits of 43 tree species in a Bolivian dry deciduous forest. Sampling was confined to small

Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N2O

Directory of Open Access Journals (Sweden)

K. Pilegaard

2006-01-01

Full Text Available Soil emissions of NO and N2O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous and different nitrogen loads. Geographically they range from Finland in the north to Italy in the south and from Hungary in the east to Scotland in the west. The highest NO emissions were observed from coniferous forests, whereas the lowest NO emissions were observed from deciduous forests. The NO emissions from coniferous forests were highly correlated with N-deposition. The site with the highest average annual emission (82 μg NO-N m−2 h−1 was a spruce forest in South-Germany (Höglwald receiving an annual N-deposition of 2.9 g m−2. NO emissions close to the detection limit were observed from a pine forest in Finland where the N-deposition was 0.2 g N m−2 a−1. No significant correlation between N2O emission and N-deposition was found. The highest average annual N2O emission (20 μg N2O-N m−2 h−1 was found in an oak forest in the Mátra mountains (Hungary receiving an annual N-deposition of 1.6 g m−2. N2O emission was significantly negatively correlated with the C/N ratio. The difference in N-oxide emissions from soils of coniferous and deciduous forests may partly be explained by differences in N-deposition rates and partly by differences in characteristics of the litter layer and soil. NO was mainly derived from nitrification whereas N2O was mainly derived from denitrification. In general, soil moisture is lower at coniferous sites (at least during spring time and the litter layer of coniferous forests is thick and well aerated favouring nitrification and thus release of NO. Conversely, the higher rates of denitrification in deciduous forests due to a compact and moist litter layer lead to N2O production and NO consumption in the soil. The two factors soil moisture and soil temperature are

Expansion of deciduous tall shrubs but not evergreen dwarf shrubs inhibited by reindeer in Scandes mountain range.

Science.gov (United States)

Vowles, Tage; Gunnarsson, Bengt; Molau, Ulf; Hickler, Thomas; Klemedtsson, Leif; Björk, Robert G

2017-11-01

One of the most palpable effects of warming in Arctic ecosystems is shrub expansion above the tree line. However, previous studies have found that reindeer can influence plant community responses to warming and inhibit shrubification of the tundra.We revisited grazed (ambient) and ungrazed study plots (exclosures), at the southern as well as the northern limits of the Swedish alpine region, to study long-term grazing effects and vegetation changes in response to increasing temperatures between 1995 and 2011, in two vegetation types (shrub heath and mountain birch forest).In the field layer at the shrub heath sites, evergreen dwarf shrubs had increased in cover from 26% to 49% but were unaffected by grazing. Deciduous dwarf and tall shrubs also showed significant, though smaller, increases over time. At the birch forest sites, the increase was similar for evergreen dwarf shrubs (20-48%) but deciduous tall shrubs did not show the same consistent increase over time as in the shrub heath.The cover and height of the shrub layer were significantly greater in exclosures at the shrub heath sites, but no significant treatment effects were found on species richness or diversity.July soil temperatures and growing season thawing degree days (TDD) were higher in exclosures at all but one site, and there was a significant negative correlation between mean shrub layer height and soil TDD at the shrub heath sites. Synthesis . This study shows that shrub expansion is occurring rapidly in the Scandes mountain range, both above and below the tree line. Tall, deciduous shrubs had benefitted significantly from grazing exclosure, both in terms of cover and height, which in turn lowered summer soil temperatures. However, the overriding vegetation shift across our sites was the striking increase in evergreen dwarf shrubs, which were not influenced by grazing. As the effects of an increase in evergreen dwarf shrubs and more recalcitrant plant litter may to some degree counteract some of

Predicting the responses of forest distribution and aboveground biomass to climate change under RCP scenarios in southern China.

Science.gov (United States)

Dai, Erfu; Wu, Zhuo; Ge, Quansheng; Xi, Weimin; Wang, Xiaofan

2016-11-01

In the past three decades, our global climate has been experiencing unprecedented warming. This warming has and will continue to significantly influence the structure and function of forest ecosystems. While studies have been conducted to explore the possible responses of forest landscapes to future climate change, the representative concentration pathways (RCPs) scenarios under the framework of the Coupled Model Intercomparison Project Phase 5 (CMIP5) have not been widely used in quantitative modeling research of forest landscapes. We used LANDIS-II, a forest dynamic landscape model, coupled with a forest ecosystem process model (PnET-II), to simulate spatial interactions and ecological succession processes under RCP scenarios, RCP2.6, RCP4.5 and RCP8.5, respectively. We also modeled a control scenario of extrapolating current climate conditions to examine changes in distribution and aboveground biomass (AGB) among five different forest types for the period of 2010-2100 in Taihe County in southern China, where subtropical coniferous plantations dominate. The results of the simulation show that climate change will significantly influence forest distribution and AGB. (i) Evergreen broad-leaved forests will expand into Chinese fir and Chinese weeping cypress forests. The area percentages of evergreen broad-leaved forests under RCP2.6, RCP4.5, RCP8.5 and the control scenarios account for 18.25%, 18.71%, 18.85% and 17.46% of total forest area, respectively. (ii) The total AGB under RCP4.5 will reach its highest level by the year 2100. Compared with the control scenarios, the total AGB under RCP2.6, RCP4.5 and RCP8.5 increases by 24.1%, 64.2% and 29.8%, respectively. (iii) The forest total AGB increases rapidly at first and then decreases slowly on the temporal dimension. (iv) Even though the fluctuation patterns of total AGB will remain consistent under various future climatic scenarios, there will be certain responsive differences among various forest types. © 2016

Sources of nitrous oxide emitted from European forest soils

Directory of Open Access Journals (Sweden)

P. Ambus

2006-01-01

Full Text Available Forest ecosystems may provide strong sources of nitrous oxide (N2O, which is important for atmospheric chemical and radiative properties. Nonetheless, our understanding of controls on forest N2O emissions is insufficient to narrow current flux estimates, which still are associated with great uncertainties. In this study, we have investigated the quantitative and qualitative relationships between N-cycling and N2O production in European forests in order to evaluate the importance of nitrification and denitrification for N2O production. Soil samples were collected in 11 different sites characterized by variable climatic regimes and forest types. Soil N-cycling and associated production of N2O was assessed following application of 15N-labeled nitrogen. The N2O emission varied significantly among the different forest soils, and was inversely correlated to the soil C:N ratio. The N2O emissions were significantly higher from the deciduous soils (13 ng N2O-N cm-3 d-1 than from the coniferous soils (4 ng N2O-N cm-3 d-1. Nitrate (NO3- was the dominant substrate for N2O with an average contribution of 62% and exceeding 50% at least once for all sites. The average contribution of ammonium (NH4+ to N2O averaged 34%. The N2O emissions were correlated with gross nitrification activities, and as for N2O, gross nitrification was also higher in deciduous soils (3.4 µg N cm-3 d-1 than in coniferous soils (1.1 µg N cm-3 d-1. The ratio between N2O production and gross nitrification averaged 0.67% (deciduous and 0.44% (coniferous. Our study suggests that changes in forest composition in response to land use activities and global change may have implications for regional budgets of greenhouse gases. From the study it also became clear that N2O emissions were driven by the nitrification activity, although the N2O was produced per se mainly from denitrification. Increased nitrification in response to accelerated N inputs predicted for forest ecosystems in Europe may

Atmospheric deposition in coniferous and deciduous tree stands in Poland

Science.gov (United States)

Kowalska, Anna; Astel, Aleksander; Boczoń, Andrzej; Polkowska, Żaneta

2016-05-01

The objective of this study was to assess the transformation of precipitation in terms of quantity and chemical composition following contact with the crown layer in tree stands with varied species composition, to investigate the effect of four predominant forest-forming species (pine, spruce, beech, and oak) on the amount and composition of precipitation reaching forest soils, and to determine the sources of pollution in atmospheric precipitation in forest areas in Poland. The amount and chemical composition (pH, electric conductivity, alkalinity, and chloride, nitrate, sulfate, phosphate, ammonium, calcium, magnesium, sodium, potassium, iron aluminum, manganese, zinc, copper, total nitrogen, and dissolved organic carbon contents) of atmospheric (bulk, BP) and throughfall (TF) precipitation were studied from January to December 2010 on twelve forest monitoring plots representative of Polish conditions. The study results provided the basis for the determination of the fluxes of pollutants in the forest areas of Poland and allowed the comparison of such fluxes with values provided in the literature for European forest areas. The transformation of precipitation in the canopy was compared for different tree stands. The fluxes of substances in an open field and under canopy were influenced by the location of the plot, including the regional meteorological conditions (precipitation amounts), vicinity of the sea (effect of marine aerosols), and local level of anthropogenic pollution. Differences between the plots were higher in TF than in BP. The impact of the vegetation cover on the chemical composition of precipitation depended on the region of the country and dominant species in a given tree stand. Coniferous species tended to cause acidification of precipitation, whereas deciduous species increased the pH of TF. Pine and oak stands enriched precipitation with components that leached from the canopy (potassium, manganese, magnesium) to a higher degree than spruce and

Litter-dwelling arthropod abundance peaks near coarse woody debris in loblolly pine forests of the southeastern United States

Science.gov (United States)

Michael D. Ulyshen; James L. Hanula

2009-01-01

litter-dwelling arthropod and other invertebrate taxa (e.g., Isopoda, Chilopoda, Diplopoda, Araneae, Pseudoscorpionida, Coleoptera, and Gastropoda) are more numerous near dead wood than away from it in the broad-leaved forests of Europe(Jabin et al. 2004; Topp et al. 2006a, 2006b; Kappes et al. 2006; Kappes 2006; Jabin et al. 2007) and...

CHEMICAL COMPOSITION, IN VITRO RUMEN FERMENTATION, AND DIGESTIBILITY OF SELECTED BROWSE SPECIES BY BUFFALOES (Bubalus bubalis L. AT A SEMI-DECIDUOUS FOREST IN VENEZUELA

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Álvaro José Ojeda

2013-01-01

Full Text Available To determine the chemical composition and nutritive value of selected browse species by buffaloes (Bubalus bubalis L. in a silvopastoral system at a semi-deciduous tropical forest (SDTF, epidermal fragments in fecal samples from 14 males of Murrah breed were evaluated. The animals grazed for 91 days in 85 ha located in Portuguesa State, Venezuela, of which 35 ha corresponded to natural grass pastures (969.3 ± 28.6 kg DM ha-1, and the rest to SDTF with 463 plant ha-1. Eleven botanical families and 22 species were identified, 40.9% belonged to the Fabaceae family. The specie Guazuma ulmifolia (Sterculiaceae had the highest relative dominancy (60.4% and an Importance Value Index of 162.6. 60.4% of epidermal fragments corresponded to herbaceous Poaceae, and the rest was distributed among five different species, with the highest occurrence (94.6% for Samanea saman and Sida acuta. There were differences (P

Forest owners' willingness to accept contracts for ecosystem service provision is sensitive to additionality

DEFF Research Database (Denmark)

Vedel, Suzanne Elizabeth; Jacobsen, Jette Bredahl; Thorsen, Bo Jellesmark

2015-01-01

A key prerequisite to ensure that payment for ecosystem services is effective is that the management measures landowners are paid to undertake are in fact additional to the status quo and hence bring about a change in provision. We investigated Danish forest owners' preferences for conditional...... owners may already provide some of these, e.g., if they derive private benefits from them, in which case additionality becomes an issue. This study investigates the link between forest owners' current management and their willingness to accept (WTA) payments for providing specific ecosystem services...... contracts for the provision of ecosystem services in Natura 2000 policies in a sample covering 12.5% of the total private forest area. This involves allowing old trees to decay naturally, setting aside forest areas, accepting a fixed percentage of broadleaves and increasing access for the public. Forest...

Contrasting drivers and trends of coniferous and deciduous tree growth in interior Alaska.

Science.gov (United States)

Cahoon, Sean M P; Sullivan, Patrick F; Brownlee, Annalis H; Pattison, Robert R; Andersen, Hans-Erik; Legner, Kate; Hollingsworth, Teresa N

2018-03-22

The boreal biome represents approximately one third of the world's forested area and plays an important role in global biogeochemical and energy cycles. Numerous studies in boreal Alaska have concluded that growth of black and white spruce is declining as a result of temperature-induced drought stress. The combined evidence of declining spruce growth and changes in the fire regime that favor establishment of deciduous tree species has led some investigators to suggest the region may be transitioning from dominance by spruce to dominance by deciduous forests and/or grasslands. Although spruce growth trends have been extensively investigated, few studies have evaluated long-term radial growth trends of the dominant deciduous species (Alaska paper birch and trembling aspen) and their sensitivity to moisture availability. We used a large and spatially extensive sample of tree cores from interior Alaska to compare long-term growth trends among contrasting tree species (white and black spruce vs. birch and aspen). All species showed a growth peak in the mid-1940s, although growth following the peak varied strongly across species. Following an initial decline from the peak, growth of white spruce showed little evidence of a trend, while black spruce and birch growth showed slight growth declines from ~1970 to present. Aspen growth was much more variable than the other species and showed a steep decline from ~1970 to present. Growth of birch, black and white spruce was sensitive to moisture availability throughout most of the tree-ring chronologies, as evidenced by negative correlations with air temperature and positive correlations with precipitation. However, a positive correlation between previous July precipitation and aspen growth disappeared in recent decades, corresponding with a rise in the population of the aspen leaf miner (Phyllocnistis populiella), an herbivorous moth, which may have driven growth to a level not seen since the early 20th century. Our results

Ectopic decidual reaction mimicking irritable bowel syndrome: a case report.

Directory of Open Access Journals (Sweden)

Soraya Salehgargari

2014-01-01

Full Text Available Ectopic decidualization with gross involvement of the peritoneum is one of the rare findings in pregnant women particularly when ectopic decidualization disseminated as an asymptomatic intra-abdominal nodule. We present here a case of an ectopic decidualization in a 33-year-old pregnant woman with symptoms of irritable bowel syndrome during pregnancy.

Growth Decline Linked to Warming-Induced Water Limitation in Hemi-Boreal Forests

OpenAIRE

Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A.; Badmaeva, Natalya K.; Sandanov, Denis V.

2012-01-01

Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal fore...

Predicting the spatial distribution of leaf litterfall in a mixed deciduous forest

NARCIS (Netherlands)

Staelens, Jeroen; Nachtergale, Lieven; Luyssaert, Sebastiaan

2004-01-01

An accurate prediction of the spatial distribution of litterfall can improve insight in the interaction between the canopy layer and forest floor characteristics, which is a key feature in forest nutrient cycling. Attempts to model the spatial variability of litterfall have been made across forest

Modeling forest dynamics along climate gradients in Bolivia

Science.gov (United States)

Seiler, C.; Hutjes, R. W. A.; Kruijt, B.; Quispe, J.; Añez, S.; Arora, V. K.; Melton, J. R.; Hickler, T.; Kabat, P.

2014-05-01

Dynamic vegetation models have been used to assess the resilience of tropical forests to climate change, but the global application of these modeling experiments often misrepresents carbon dynamics at a regional level, limiting the validity of future projections. Here a dynamic vegetation model (Lund Potsdam Jena General Ecosystem Simulator) was adapted to simulate present-day potential vegetation as a baseline for climate change impact assessments in the evergreen and deciduous forests of Bolivia. Results were compared to biomass measurements (819 plots) and remote sensing data. Using regional parameter values for allometric relations, specific leaf area, wood density, and disturbance interval, a realistic transition from the evergreen Amazon to the deciduous dry forest was simulated. This transition coincided with threshold values for precipitation (1400 mm yr-1) and water deficit (i.e., potential evapotranspiration minus precipitation) (-830 mm yr-1), beyond which leaf abscission became a competitive advantage. Significant correlations were found between modeled and observed values of seasonal leaf abscission (R2 = 0.6, p days. Decreasing rainfall trends were simulated to reduce GPP in the Amazon. The current model setup provides a baseline for assessing the potential impacts of climate change in the transition zone from wet to dry tropical forests in Bolivia.

Uav-Based Photogrammetric Point Clouds and Hyperspectral Imaging for Mapping Biodiversity Indicators in Boreal Forests

Science.gov (United States)

Saarinen, N.; Vastaranta, M.; Näsi, R.; Rosnell, T.; Hakala, T.; Honkavaara, E.; Wulder, M. A.; Luoma, V.; Tommaselli, A. M. G.; Imai, N. N.; Ribeiro, E. A. W.; Guimarães, R. B.; Holopainen, M.; Hyyppä, J.

2017-10-01

Biodiversity is commonly referred to as species diversity but in forest ecosystems variability in structural and functional characteristics can also be treated as measures of biodiversity. Small unmanned aerial vehicles (UAVs) provide a means for characterizing forest ecosystem with high spatial resolution, permitting measuring physical characteristics of a forest ecosystem from a viewpoint of biodiversity. The objective of this study is to examine the applicability of photogrammetric point clouds and hyperspectral imaging acquired with a small UAV helicopter in mapping biodiversity indicators, such as structural complexity as well as the amount of deciduous and dead trees at plot level in southern boreal forests. Standard deviation of tree heights within a sample plot, used as a proxy for structural complexity, was the most accurately derived biodiversity indicator resulting in a mean error of 0.5 m, with a standard deviation of 0.9 m. The volume predictions for deciduous and dead trees were underestimated by 32.4 m3/ha and 1.7 m3/ha, respectively, with standard deviation of 50.2 m3/ha for deciduous and 3.2 m3/ha for dead trees. The spectral features describing brightness (i.e. higher reflectance values) were prevailing in feature selection but several wavelengths were represented. Thus, it can be concluded that structural complexity can be predicted reliably but at the same time can be expected to be underestimated with photogrammetric point clouds obtained with a small UAV. Additionally, plot-level volume of dead trees can be predicted with small mean error whereas identifying deciduous species was more challenging at plot level.

Neural network modelling of rainfall interception in four different forest stands

OpenAIRE

Ibrahim Yurtseven; Mustafa Zengin

2013-01-01

The objective of this study is to reveal whether it is possible to predict rainfall, throughfall and stemflow in forest ecosystems with less effort, using several measurements of rainfall interception (hereafter interception) and an artificial neural network based linear regression model (ANN model). To this end, the Kerpe Research Forest in the province of Kocaeli, which houses stands of mixed deciduous-broadleaf forest (Castanea sativa Mill., Fagus orientalis Lipsky, Quercus spp.), black pi...

SRTM-DEM and Landsat ETM+ data for mapping tropical dry forest cover and biodiversity assessment in Nicaragua

Science.gov (United States)

S.E. Sesnie; S.E. Hagell; S.M. Otterstrom; C.L. Chambers; B.G. Dickson

2008-01-01

Tropical dry and deciduous forest comprises as much as 42% of the world’s tropical forests, but has received far less attention than forest in wet tropical areas. Land use change threatens to greatly reduce the extent of dry forest that is known to contain high levels of plant and animal diversity. Forest fragmentation may further endanger arboreal mammals that play...

[Vertical distribution and community diversity of butterflies in Yaoluoping National Nature Reserve, Anhui, China].

Science.gov (United States)

Wang, Song; Bao, Fang-yin; Mei, Bai-mao; Ding, Shi-chao

2009-09-01

By the methods of fixed point, line intercept, and random investigation, the vertical distribution and community diversity of butterflies in Yaoluoping National Nature Reserve were investigated from 2005 to 2008. A total of 3681 specimen were collected, belonging to 111 species, 69 genera, and 10 families, among which, Nymphalidae had the higher species number, individual's number, and diversity index than the other families. The butterflies in the study area were a mixture of Oriental and Palaearetic species, with the Oriental species diminished gradually and the Palaearetic components increased gradually with increasing altitude. Among the three vertical zones ( 1200 m in elevation), that of 800-1200 m had the most abundant species of butterflies; and among the six habitat types (deciduous broad-leaved forest, evergreen conifer forest, conifer-broad leaf mixed forest, bush and secondary forest, farmland, and residential area), bush and secondary forest had the higher species number, individual's number, and diversity index of butterflies, while farmland had the lowest diversity index. The similarity coefficient of butterfly species between the habitats was mainly dependent on vegetation type, i.e., the more the difference of vegetation type, the lesser the species similarity coefficient between the habitats, which was the highest (0.61) between conifer-broad leaf mixed forest and bush and secondary forest, and the lowest (0. 20) between evergreen conifer forest and bush and secondary forest.

Effects of Drought and Rewetting on Growth and Gas Exchange of Minor European Broadleaved Tree Species

Directory of Open Access Journals (Sweden)

Jörg Kunz

2016-10-01

Full Text Available Widespread and economically important European tree species such as Norway spruce, Scots pine, and European beech are projected to be negatively affected by the increasing intensity and frequency of dry and hot conditions in a future climate. Hence, there is an increasing need to investigate the suitability of presumably more drought tolerant species to ensure future ecological stability, biodiversity, and productivity of forests. Based on their distribution patterns and climatic envelopes, the rare, minor broadleaved tree species Sorbus torminalis ((L. CRANTZ, S. domestica (L., Acer campestre (L., and A. platanoides (L. are assumed to be drought tolerant, however, there is only limited experimental basis to support that notion. This study aimed at quantifying growth and gas exchange of seedlings of these species during drought conditions, and their capacity to recover following drought. For that purpose, they were compared to the common companion species Quercus petraea ((MATTUSCHKA LIEBL. and Fagus sylvatica (L.. Here, potted seedlings of these species were exposed to water limitation followed by rewetting cycles in a greenhouse experiment. Photosynthesis and transpiration rates, stomatal conductance as well as root and shoot growth rates indicated a high drought resistance of A. campestre and A. platanoides. Sorbus domestica showed a marked ability to recover after drought stress. Therefore, we conclude that these minor tree species have the potential to enrich forests on drought-prone sites. Results from this pot experiment need to be complemented by field studies, in which the drought response of the species is not influenced by restrictions to root development.

Development of a spatial forest data base for the eastern boreal forest region of Ontario. Forest fragmentation and biodiversity project technical report No. 14

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

In 1991, a spatial forest database over large regions of Ontario was initiated as the basis for research into forest fragmentation and biodiversity using data generated from the digital analysis of LANDSAT thematic mapper satellite data integrated into a geographic information system (GIS). The project was later extended into the eastern segment of the Boreal forest system. This report describes preparation of the spatial forest data base over the eastern Boreal Forest Region that extends from the northern boundary of the Great Lakes-St. Lawrence Forest Region and the southern margin of the James Bay Lowland, between the Ontario-Quebec border and a point west of Michipicoten on Lake Superior. The report describes the methodology used to produce the data base and results, including mapping of water, dense and sparse conifer forest, mixed forest, dense and sparse deciduous forest, poorly vegetated areas, recent cutovers of less than 10 years, old cutovers and burns, recent burns of less than 10 years, wetlands, bedrock outcrops, agriculture, built-up areas, and mine tailings.

Temporal variations of atmospheric CO2 concentration in a temperate deciduous forest in central Japan

International Nuclear Information System (INIS)

Murayama, Shohei; Saigusa, Nobuko; Yamamoto, Susumu; Kondo, Hiroaki; Eguchi, Yozo; Chan, Douglas

2003-01-01

In order to examine the temporal variation of the atmospheric CO 2 concentration in a temperate deciduous forest, and its relationship with meteorological conditions, continuous measurements of CO 2 and meteorological parameters have been made since 1993 on a tower at Takayama in the central part of Japan. In addition to an average secular increase in atmospheric CO 2 of 1.8 ppm/yr, diurnal variation with a maximum during the night-time to early morning and a minimum in the afternoon is observed from late spring to early fall; the diurnal cycle is not so clearly observed in the remaining seasons of the year. A concentration difference between above and below the canopy, and its diurnal variation, can also be seen clearly in summer. Daily mean concentration data show a prominent seasonal cycle. The maximum and the minimum of the seasonal cycle occur in April and from mid August to mid September, respectively. Day-to-day changes in the diurnal cycle of CO 2 are highly dependent on the day-to-day variations in meteorological conditions. However, CO 2 variations on longer time scales (>10 d) appear to be linearly related to changes in respiration. At Takayama, variations in the 10-d standard deviation of daily mean CO 2 data and 10-d averaged respiration show distinct relationships with soil temperature during spring and fall seasons. In spring, respiration has a stronger exponential dependence on soil temperature than in fall. Interestingly, in summer when soil temperature becomes greater than about 15 deg C, biological respiration becomes more variable and independent of the soil temperature. Thus, at the Takayama site, the Q10 relationship is seasonally dependent, and does not represent well the biological respiration process when the soil temperature rises above 15 deg C

Influence of temperature and organic matter content on soil respiration in a deciduous oak forest

Directory of Open Access Journals (Sweden)

Zsolt Kotroczó

2014-12-01

Full Text Available The increasing temperature enhances soil respiration differently depend on different conditions (soil moisture, soil organic matter, the activity of soil microbes. It is an essential factor to predicting the effect of climate change on soil respiration. In a temperate deciduous forest (North-Hungary we added or removal aboveground and belowground litter to determine total soil respiration. We investigated the relationship between total soil CO2 efflux, soil moisture and soil temperature. Soil CO2 efflux was measured at each plot using chamber based soil respiration measurements. We determined the temperature sensitivity of soil respiration. The effect of doubled litter was less than the effect of removal. We found that temperature was more influential in the control of soil respiration than soil moisture in litter removal treatments, particularly in the wetter root exclusion treatments (NR and NI (R2: 0.49-0.61. Soil moisture (R2: 0.18-0.24 and temperature (R2: 0.18-0.20 influenced soil respiration similarly in treatments, where soil was drier (Control, Double Litter, Double Wood. A significantly greater increase in temperature induced higher soil respiration were significantly higher (2-2.5-fold in root exclusion treatments, where soil was wetter throughout the year, than in control and litter addition treatments. The highest bacterial and fungal count was at the DL treatment but the differences is not significant compared to the Control. The bacterial number at the No Litter, No Root, No Input treatment was significantly lower at the Control. Similar phenomenon can be observed at the fungal too, but the differences are not significant. The results of soil respiration suggest that the soil aridity can reduce soil respiration increases with the temperature increase. Soil bacterial and fungal count results show the higher organic matter content and soil surface cover litter favors the activity.

Plant biodiversity patterns on Helan Mountain, China

Science.gov (United States)

Jiang, Yuan; Kang, Muyi; Zhu, Yuan; Xu, Guangcai

2007-09-01

A case study was conducted to mountainous ecosystems in the east side of Helan Mountain, located in the transitional zone between steppe and desert regions of China, aiming to reveal the influences of four environmental factors on features of plant biodiversity—the spatial pattern of vegetation types, and the variation of α- and β-diversities in vegetation and flora. Field surveys on vegetation and flora and on environmental factors were conducted, and those field data were analyzed through CCA (Canonical Correspondence Analysis), and through Shannon-Weiner index for α-diversity and Sørensen index for β-diversity. The preliminary results are: (1) Ranked in terms of their impacts on spatial patterns of plant biodiversity, the four selected environmental factors would be: elevation > location > slope > exposure. (2) The variation of Shannon-Weiner index along the altitudinal gradient is similar to that of species amount within altitudinal belts spanning 200 m each, which suggests a unimodal relationship between the species richness and the environmental condition with regards to altitudinal factors. Both the Shannon-Weiner index and the species richness within each altitudinal belt reach their maximum at elevation range from about 1700 to 2000 m a.s.l. (3) The altitudinal extent with the highest Shannon-Weiner index is identical to the range, where both the deciduous broad-leaved forest, and the temperate evergreen coniferous and deciduous broad-leaved mixed forest distribute. The altitudinal range from 1700 to 2200 m a.s.l. is the sector with both high level of species richness and diversified vegetation types. (4) The variation of β-diversity along the altitude is consistent with the vegetation vertical zones. According to the Sørensen index between each pair of altitudinal belts, the transition of vegetation spectrum from one zone to another, as from the base horizontal zone, the desert steppe, to the first vertical zone, the mountain open forest and

Seasonal Variability of Ground Water Levels in the Puszcza Zielonka Forest

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Grajewski Sylwester

2014-07-01

Full Text Available The paper presents results of studies on seasonal variability of ground water tables recorded in long-term observations of water levels in the Puszcza Zielonka forest complex. The Puszcza Zielonka Forest is located in the middle part of the Warta basin in the central part of the Wielkopolska region. Its western boundary is located approx. 6 km north-east of Poznań. The area is situated in the western part of the Wielkopolska-Mazovian climatic region. The natural landscape is of young glacial type of Pleistocene and Holocene formation. For this reason parent materials for soils in this area were mainly postglacial drifts, deposits coming from the Poznań stage of the Würm glaciation. In terms of granulometric composition these were mainly low clayey sands deposited on loose sands with an admixture of gravel and eroded sandy clay. Scots pine is the dominant species. Oaks, alders, larches and scarce spruces are also found in this area. Predominant sites include fresh mixed forest, fresh mixed coniferous forest, fresh broadleaved forest and alder swamp forest.

The impact of growing-season length variability on carbon assimilation and evapotranspiration over 88 years in the eastern US deciduous forest

Science.gov (United States)

White; Running; Thornton

1999-02-01

Recent research suggests that increases in growing-season length (GSL) in mid-northern latitudes may be partially responsible for increased forest growth and carbon sequestration. We used the BIOME-BGC ecosystem model to investigate the impacts of including a dynamically regulated GSL on simulated carbon and water balance over a historical 88-year record (1900-1987) for 12 sites in the eastern USA deciduous broadleaf forest. For individual sites, the predicted GSL regularly varied by more than 15 days. When grouped into three climatic zones, GSL variability was still large and rapid. There is a recent trend in colder, northern sites toward a longer GSL, but not in moderate and warm climates. The results show that, for all sites, prediction of a long GSL versus using the mean GSL increased net ecosystem production (NEP), gross primary production (GPP), and evapotranspiration (ET); conversely a short GSL is predicted to decrease these parameters. On an absolute basis, differences in GPP between the dynamic and mean GSL simulations were larger than the differences in NEP. As a percentage difference, though, NEP was much more sensitive to changes in GSL than were either GPP or ET. On average, a 1-day change in GSL changed NEP by 1.6%, GPP by 0.5%, and ET by 0.2%. Predictions of NEP and GPP in cold climates were more sensitive to changes in GSL than were predictions in warm climates. ET was not similarly sensitive. First, our results strongly agree with field measurements showing a high correlation between NEP and dates of spring growth, and second they suggest that persistent increases in GSL may lead to long-term increases in carbon storage.

miRNA signature and Dicer requirement during human endometrial stromal decidualization in vitro.

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Carlos Estella

Full Text Available Decidualization is a morphological and biochemical transformation of endometrial stromal fibroblast into differentiated decidual cells, which is critical for embryo implantation and pregnancy establishment. The complex regulatory networks have been elucidated at both the transcriptome and the proteome levels, however very little is known about the post-transcriptional regulation of this process. miRNAs regulate multiple physiological pathways and their de-regulation is associated with human disorders including gynaecological conditions such as endometriosis and preeclampsia. In this study we profile the miRNAs expression throughout human endometrial stromal (hESCs decidualization and analyze the requirement of the miRNA biogenesis enzyme Dicer during this process. A total of 26 miRNAs were upregulated and 17 miRNAs downregulated in decidualized hESCs compared to non-decidualized hESCs. Three miRNAs families, miR-181, miR-183 and miR-200, are down-regulated during the decidualization process. Using miRNAs target prediction algorithms we have identified the potential targets and pathways regulated by these miRNAs. The knockdown of Dicer has a minor effect on hESCs during in vitro decidualization. We have analyzed a battery of decidualization markers such as cell morphology, Prolactin, IGFBP-1, MPIF-1 and TIMP-3 secretion as well as HOXA10, COX2, SP1, C/EBPß and FOXO1 expression in decidualized hESCs with decreased Dicer function. We found decreased levels of HOXA10 and altered intracellular organization of actin filaments in Dicer knockdown decidualized hESCs compared to control. Our results provide the miRNA signature of hESC during the decidualization process in vitro. We also provide the first functional characterization of Dicer during human endometrial decidualization although surprisingly we found that Dicer plays a minor role regulating this process suggesting that alternative biogenesis miRNAs pathways must be involved in human

Transpiration characteristics of forests and shrubland under land cover change within the large caldera of Mt. Aso, Japan

Science.gov (United States)

Miyazawa, Y.; Inoue, A.; Maruyama, A.

2013-12-01

Grassland within a caldera of Mt. Aso has been maintained for fertilizer production from grasses and cattle feeding. Due to the changes in the agricultural and social structure since 1950's, a large part of the grassland was converted to plantations or abandoned to shrublands. Because vegetations of different plant functional types differ in evapotranspiration; ET, a research project was launched to examine the effects of the ongoing land use change on the ET within the caldera, and consequently affect the surface and groundwater discharge of the region. As the part of the project, transpiration rate; E of the major 3 forest types were investigated using sap flow measurements. Based on the measured data, stomatal conductance; Gs was inversely calculated and its response to the environmental factors was modeled using Jarvis-type equation in order to estimate ET of a given part of the caldera based on the plant functional type and the weather data. The selected forests were conifer plantation, deciduous broadleaved plantation and shrubland, which were installed with sap flow sensors to calculate stand-level transpiration rate. Sap flux; Js did not show clear differences among sites despite the large differences in sapwood area. In early summer solar radiation was limited to low levels due to frequent rainfall events and therefore, Js was the function of solar radiation rather than other environmental factors, such as vapor pressure deficit and soil water content. Gs was well regressed with the vapor pressure deficit and solar radiation. The estimated E based on Gs model and the weather data was 0.3-1.2 mm day-1 for each site and was comparable to the E of grassland in other study sites. Results suggested that transpiration rate in growing was not different between vegetations but its annual value are thought to differ due to the different phenology.

Effects of gamma radiation on biomass production of ground vegetation under broadleaved forests of northern Wisconsin

International Nuclear Information System (INIS)

Zavitkovski, J.; Salmonson, B.J.

1977-01-01

Effects of gamma irradiation (10,000-Ci 137 Cs source) for one growing season on biomass production of ground vegetation under northern Wisconsin aspen and maple-aspen-birch forests and on an abandoned logging road were evaluated during and 1 year after irradiation. No significant changes in production were determined during the irradiation year. One year later three distinct zones--semidevastated, herbaceous, and original forest--developed along the radiation gradient. Biomass production under forest canopies decreased significantly in the semidevastated zone, increased significantly in the herbaceous zone (primarily responding to additional light), and remained unchanged under the original forest. Logging-road vegetation responded similarly, but the changes were restricted within higher radiation doses. At comparable levels of radiation, production of species of the logging-road vegetation was affected less than that of species under forest canopies. Such a trend was predictable from the generally smaller interphase chromosome volumes of the species on the logging road and from their ability to survive in severe habitats

SEASONAL VARIATION IN LIGHT TRANSMISSION AND CANOPY GAPS OF DECIDUOUS ROADSIDE VEGETATION: ASSESSMENT WITHIN FOREST LANDSCAPE

OpenAIRE

Öztürk, Melih; Gökyer, Ercan

2015-01-01

Deciduous roadside vegetation exhibits seasonal patterns of foliage with varying colors and numbers. Hence the alternating percentage of the gaps within the roadside canopy allows changing percentages of light transmission throughout the year. The leafless roadside vegetation in winter is sequentially subject to budburst, flushing, and development stages until the summer, when the leaves are fully developed both in size and number. Then, defoliation follows senescence, and fading and fall sta...

The behavior of 137Cs in the soil-forest plants system

International Nuclear Information System (INIS)

Spiridonov, S.; Fesenko, S.; Avila, R.

1999-01-01

A model has been developed which simulates the behavior of 137 Cs in forest litter and soil, as well as seasonal and long-term dynamics of 137 CS content in forest plants. The long-term cycles of 137 CS migration are described as an integrated result of multiple annual cycles. The model results demonstrate a satisfactory coincidence with the experimental data. A set of model parameters is provided for each of four different types of forest (coniferous and deciduous forest; automorphic and semi-hydromorphic landscapes). The model allows an evaluation of the effects of countermeasures implemented in the contaminated forest. Refs. 1 (author)

Forest Vegetation with Festuca drymeja in Slovakia – Syntaxonomy and Ecology

Czech Academy of Sciences Publication Activity Database

Máliš, František; Jarolímek, I.; Kliment, J.; Slezák, M.

2013-01-01

Roč. 53, č. 2 (2013), s. 265-288 ISSN 0079-2047 Institutional support: RVO:67985939 Keywords : Symphyto cordatae-Fagion * Carpathians * temperate deciduous and mixed forests Subject RIV: EF - Botanics Impact factor: 0.388, year: 2013

EAB induced tree mortality impacts ecosystem respiration and tree water use in an experimental forest

Science.gov (United States)

Charles E. Flower; Douglas J. Lynch; Kathleen S. Knight; Miquel A. Gonzales-Meler

2011-01-01

The invasive emerald ash borer (Agrilus planipennis Fairmaire, EAB) has been spreading across the forest landscape of the Midwest resulting in the rapid decline of ash trees (Fraxinus spp.). Ash trees represent a dominant riparian species in temperate deciduous forests of the Eastern United States (USDA FIA Database). Prior...

Fire and the production of Astraeus odoratus (Basidiomycetes sporocarps in deciduous dipterocarp-oak forests of northern Thailand

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Keegan H. Kennedy

2012-12-01

Full Text Available The genus Astraeus (Diplocystidiaceae forms ectomycorrhizal associations with many tree species and is a common gasteromycete in tropical and temperate ecosystems worldwide. In Thailand, Astraeus is most prevalent in deciduous dipterocarp-oak forest (DOF in the north and north-east and its ecology is uniquely associated with fire. Rural villagers often burn the seasonally dry DOF ground vegetation causing significant environmental disturbance to promote the growth of Astraeus sporocraps—a local culinary delicacy and important source of household income. The purpose of this work is to investigate whether the practice of burning DOF stimulates the production of Astraeus sporocarps in DOF. Burned and unburned Astraeus habitat was surveyed over two years at two sites in Chiang Mai province and one site in Mae Hong Son province. Changes in soil fungi after a fire as well as vascular vegetation growing with Astraeus were studied. All sporocarps collected were identified as Astraeus odoratus. Astraeus sporocarps were found in both burned and unburned areas in 2010. In 2011, an unusually wet year, no sporocarps were found in burned or unburned areas. The top 2 cm of soil experienced high temperatures which killed fungi, but lower depths were well insulated from the heat. A wide range of vascular flora grew in Astraeus habitat, the most common tree species being Dipterocarpus tuberculatus var. tuberculatus and Dipterocarpus obtusifolius var. obtusifolius. This study shows that Astraeus can produce sporocarps without fire and future work can focus on more environmentally benign methods of harvesting this popular mushroom.

Divergence of dominant factors in soil microbial communities and functions in forest ecosystems along a climatic gradient

Science.gov (United States)

Xu, Zhiwei; Yu, Guirui; Zhang, Xinyu; He, Nianpeng; Wang, Qiufeng; Wang, Shengzhong; Xu, Xiaofeng; Wang, Ruili; Zhao, Ning

2018-03-01

Soil microorganisms play an important role in regulating nutrient cycling in terrestrial ecosystems. Most of the studies conducted thus far have been confined to a single forest biome or have focused on one or two controlling factors, and few have dealt with the integrated effects of climate, vegetation, and soil substrate availability on soil microbial communities and functions among different forests. In this study, we used phospholipid-derived fatty acid (PLFA) analysis to investigate soil microbial community structure and extracellular enzymatic activities to evaluate the functional potential of soil microbes of different types of forests in three different climatic zones along the north-south transect in eastern China (NSTEC). Both climate and forest type had significant effects on soil enzyme activities and microbial communities with considerable interactive effects. Except for soil acid phosphatase (AP), the other three enzyme activities were much higher in the warm temperate zone than in the temperate and the subtropical climate zones. The soil total PLFAs and bacteria were much higher in the temperate zone than in the warm temperate and the subtropical zones. The soil β-glucosidase (BG) and N-acetylglucosaminidase (NAG) activities were highest in the coniferous forest. Except for the soil fungi and fungi-bacteria (F/B), the different groups of microbial PLFAs were much higher in the conifer broad-leaved mixed forests than in the coniferous forests and the broad-leaved forests. In general, soil enzyme activities and microbial PLFAs were higher in primary forests than in secondary forests in temperate and warm temperate regions. In the subtropical region, soil enzyme activities were lower in the primary forests than in the secondary forests and microbial PLFAs did not differ significantly between primary and secondary forests. Different compositions of the tree species may cause variations in soil microbial communities and enzyme activities. Our results

Bone marrow origin of decidual cell precursors in the pseudopregnant mouse uterus

International Nuclear Information System (INIS)

Kearns, M.; Lala, P.K.

1982-01-01

Decidual cells are considered to be the endproduct of a hormonally induced transformation of endometrial stromal cells of the uterus. However, the source of these precursors remains unknown. This study of evaluated the possibility of their bone marrow origin by an examination of the H-2 phenotype of decidual cells in pseudopregnant bone marrow chimeras. These chimeras were produced by repopulating lethally irradiated CBA/J female (H-2k) mice with bone marrow from (CBA/J x C57BL/6J) F1 female (H-2kb) mice. Pseudopregnancy was produced with a hormonal regimen followed by an oil-induced decidual stimulus. Chimerism was evaluated radioautographically by an identification of the donor-specific Kb phenotype on cells with an immunolabeling technique with monospecific anti-H-2 serum followed by radioiodinated protein A. The extent of chimerism as indicated by the degree of Kb labeling on decidual cells as well as macrophages contained within the decidual nodules was quantitatively compared with that seen on splenic lymphocytes. Fair to good chimerism, as reflected by labeling for the donor-specific marker (Kb), was seen on splenic lymphocytes and macrophages within the decidual nodules in 6 out of 11 animals. A similar level of chimerism was detected on decidual cells in all but one of these six, in which case this was low. One animal showed low chimerism in the spleen but good chimerism on the decidual cells. The remaining four mice were nonchimeric for all three cell types. These results indicate that decidual cells and macrophages appearing within the decidual nodules of pseudopregnant mice are ultimate descendants of bone marrow cells

Holocene Vegetation Succession and Response to Climate Change on the South Bank of the Heilongjiang-Amur River, Mohe County, Northeast China

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Chao Zhao

2016-01-01

Full Text Available Pollen samples from peat sediments on the south bank of the Heilongjiang River in northern Northeast China (NE China were analyzed to reconstruct the historical response of vegetation to climate change since 7800 cal yr BP. Vegetation was found to have experienced five successions from cold-temperate mixed coniferous and broadleaved forest to forest-steppe, steppe-woodland, steppe, and finally meadow-woodland. From 7800 to 7300 cal yr BP, the study area was warmer than present, and Betula, Larix, and Picea-dominated mixed coniferous and broadleaved forests thrived. Two cooling events at 7300 cal yr BP and 4500 cal yr BP led to a decrease in Betula and other broadleaved forests, whereas herbs of Poaceae expanded, leading to forest-steppe and then steppe-woodland environments. After 2500 cal yr BP, reduced temperatures and a decrease in evaporation rates are likely to have resulted in permafrost expansion and surface ponding, with meadow and isolated coniferous forests developing a resistance to the cold-wet environment. The Holocene warm period in NE China (7800–7300 cal yr BP could have resulted in a strengthening of precipitation in northernmost NE China and encouraged the development of broadleaved forests.

Soil and soil cover changes in spruce forests after final logging

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E. M. Lapteva

2015-10-01

Full Text Available Soil cover transformation and changes of morphological and chemical properties of Albeluvisols in clear-cuttings of middle taiga spruce forests were studied. The observed changes in structure and properties of podzolic texturally-differentiated soils at cuttings of spruce forests in the middle taiga subzone do not cause their transition to any other soil type. Soil cover of secondary deciduous-coniferous forests which replace cut forests are characterized with a varied soil contour and a combination of the main type of podzolic soils under undisturbed spruce forests. The increased surface hydromorphism in cut areas causes formation of complicated sub-types of podzolic texturally differentiated soils (podzolic surface-gley soils with microprofile of podzol and enlarges their ratio (up to 35–38 % in soil cover structure. Temporary soil over-wetting at the initial (5–10 years stage of after-cutting self-restoring vegetation succession provides for soil gleyzation, improves yield and segregation of iron compounds, increases the migratory activity of humic substances. Low content and resources of total nitrogen in forest litters mark anthropogenic transformation processes of podzolic soils at this stage. Later (in 30–40 years after logging, soils in cut areas still retain signs of hydromorphism. Forest litters are denser, less acidic and thick with a low weight ratio of organic carbon as compared with Albeluvisols of undisturbed spruce forest. The upper mineral soil horizons under secondary deciduous-coniferous forests contain larger amounts of total iron, its mobile (oxalate-dissolvable components, and Fe-Mn-concretions.

Mapping Deciduous Rubber Plantation Areas and Stand Ages with PALSAR and Landsat Images

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Weili Kou

2015-01-01

Full Text Available Accurate and updated finer resolution maps of rubber plantations and stand ages are needed to understand and assess the impacts of rubber plantations on regional ecosystem processes. This study presented a simple method for mapping rubber plantation areas and their stand ages by integration of PALSAR 50-m mosaic images and multi-temporal Landsat TM/ETM+ images. The L-band PALSAR 50-m mosaic images were used to map forests (including both natural forests and rubber trees and non-forests. For those PALSAR-based forest pixels, we analyzed the multi-temporal Landsat TM/ETM+ images from 2000 to 2009. We first studied phenological signatures of deciduous rubber plantations (defoliation and foliation and natural forests through analysis of surface reflectance, Normal Difference Vegetation Index (NDVI, Enhanced Vegetation Index (EVI, and Land Surface Water Index (LSWI and generated a map of rubber plantations in 2009. We then analyzed phenological signatures of rubber plantations with different stand ages and generated a map, in 2009, of rubber plantation stand ages (≤5, 6–10, >10 years-old based on multi-temporal Landsat images. The resultant maps clearly illustrated how rubber plantations have expanded into the mountains in the study area over the years. The results in this study demonstrate the potential of integrating microwave (e.g., PALSAR and optical remote sensing in the characterization of rubber plantations and their expansion over time.

Forest litter stocks in Korean pine-broad-leaved forests of the southern Sikhote Alin

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A. V. Ivanov

2015-10-01

Full Text Available The article presents the data on the forest litter of the Korean pine-broad-leaved forests of the South of Primorsky krai. The focus of the research is plantations dominated by Korean pine; areas of the main tree species with ages of 50, 80, 130 and 200 years were selected. The dynamics of the forest litter stock in the pine and broadleaved forests of different ages according to the measurement results for the season in 2014 is stated. In the studied plantation, the forest litter stock varies between 9.7–20.3 t ha-1. The greatest value of the forest litter stock is recorded in old-growth cedar forest (200 years. Relatively high power and the stock of litter are typical for young Korean pine forest that can explain the lower speed of the litter properties change against the dynamics of taxation indicators of the forest stand. The difference between the amount of the litter in the 200-year-old and remaining pine trees are statistically significant at p = 0.05. The dependence of the litter power on the age is not revealed. The coefficient of the forest litter decomposition ranges from 2.55–10.60 that characterizes the high speed of its rotting. The highest coefficient of the litter decomposition has an old-growing pine forest. The schedule of seasonal humidity fluctuations of the forest litter on the chosen plot is made; with increasing cedar forest age, the volumetric moisture content of the forest litter increases; volumetric moisture content on the plots remain relatively unchanged during the season. The area of the Korean pine forests of Primorsky State Academy of Agriculture is 6835 ha. The amount of carbon stock in the forest litter is 38.7 thousand tons C. in this area, while the system of regional assessment of the forest carbon balance estimates this index as 24.3 tons С. The data obtained can be used to adjust the coefficients of regional assessment of the forest carbon balance for cedar forests of Primorsky krai.

Nutrient retranslocation in forest species in the Brazilian Amazon

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Murilo Rezende Machado

2016-01-01

Full Text Available Internal retranslocation is an important mechanism for nutrient conservation in plants, which depends on different factors. However, there are little data about this subject, especially on tropical forest species. This study aimed to evaluate the macronutrient retranslocation dynamic and the influence of ecological (P: pioneer x NP: non-pioneer and phenological (ND: non-deciduous x D: semideciduous / deciduous characteristics on the macronutrient content of leaves of five tree species on monospecific plantations in the Brazilian Amazon: Acacia mangium Willd., Parkia decussata Ducke, Dipteryx odorata (Aublet Willd., Jacaranda copaia (Aubl. D. Don and Swietenia macrophylla King. Photosynthetically active green leaves and senescent leaves (leaf litter were collected. Retranslocation was estimated through an equation proposed by Attiwill, Guthrie and Leuning (1978. The pioneer species presented higher foliar contents of N; the non-pioneer species presented higher contents of K, Ca and S; and the results were inconclusive for P and Mg. The deciduous species presented higher foliar contents of K and of P, whereas the foliar contents of N, Ca, Mg and S were virtually identical between the phenological groups. The internal retranslocation of foliar nutrients in pioneer and non-deciduous species was higher than that of non-pioneer and deciduous species.

Leaf litter nitrogen concentration as related to climatic factors in Eurasian forests

DEFF Research Database (Denmark)

Liu, Chunjiang; Berg, Bjørn; Kutsch, Werner

2006-01-01

The aim of this study is to determine the patterns of nitrogen (N) concentrations in leaf litter of forest trees as functions of climatic factors, annual average temperature (Temp, °C) and annual precipitation (Precip, dm) and of forest type (coniferous vs. broadleaf, deciduous vs. evergreen, Pinus...... concentration and Temp and Precip by means of regression analysis. Leaf litter data from N2-fixing species were excluded from the analysis. Results: Over the Eurasian continent, leaf litter N concentration increased with increasing Temp and Precip within functional groups such as conifers, broadleaf, deciduous....... In the context of global warming, these regression equations are useful for a better understanding and modelling of the effects of geographical and climatic factors on leaf litter N at a regional and continental scale....

FOREST ECOSYSTEM DYNAMICS ASSESSMENT AND PREDICTIVE MODELLING IN EASTERN HIMALAYA

Directory of Open Access Journals (Sweden)

S. P. S. Kushwaha

2012-09-01

Full Text Available This study focused on the forest ecosystem dynamics assessment and predictive modelling deforestation and forest cover prediction in a part of north-eastern India i.e. forest areas along West Bengal, Bhutan, Arunachal Pradesh and Assam border in Eastern Himalaya using temporal satellite imagery of 1975, 1990 and 2009 and predicted forest cover for the period 2028 using Cellular Automata Markov Modedel (CAMM. The exercise highlighted large-scale deforestation in the study area during 1975–1990 as well as 1990–2009 forest cover vectors. A net loss of 2,334.28 km2 forest cover was noticed between 1975 and 2009, and with current rate of deforestation, a forest area of 4,563.34 km2 will be lost by 2028. The annual rate of deforestation worked out to be 0.35 and 0.78% during 1975–1990 and 1990–2009 respectively. Bamboo forest increased by 24.98% between 1975 and 2009 due to opening up of the forests. Forests in Kokrajhar, Barpeta, Darrang, Sonitpur, and Dhemaji districts in Assam were noticed to be worst-affected while Lower Subansiri, West and East Siang, Dibang Valley, Lohit and Changlang in Arunachal Pradesh were severely affected. Among different forest types, the maximum loss was seen in case of sal forest (37.97% between 1975 and 2009 and is expected to deplete further to 60.39% by 2028. The tropical moist deciduous forest was the next category, which decreased from 5,208.11 km2 to 3,447.28 (33.81% during same period with further chances of depletion to 2,288.81 km2 (56.05% by 2028. It noted progressive loss of forests in the study area between 1975 and 2009 through 1990 and predicted that, unless checked, the area is in for further depletion of the invaluable climax forests in the region, especially sal and moist deciduous forests. The exercise demonstrated high potential of remote sensing and geographic information system for forest ecosystem dynamics assessment and the efficacy of CAMM to predict the forest cover change.

Forest Ecosystem Dynamics Assessment and Predictive Modelling in Eastern Himalaya

Science.gov (United States)

Kushwaha, S. P. S.; Nandy, S.; Ahmad, M.; Agarwal, R.

2011-09-01

This study focused on the forest ecosystem dynamics assessment and predictive modelling deforestation and forest cover prediction in a part of north-eastern India i.e. forest areas along West Bengal, Bhutan, Arunachal Pradesh and Assam border in Eastern Himalaya using temporal satellite imagery of 1975, 1990 and 2009 and predicted forest cover for the period 2028 using Cellular Automata Markov Modedel (CAMM). The exercise highlighted large-scale deforestation in the study area during 1975-1990 as well as 1990-2009 forest cover vectors. A net loss of 2,334.28 km2 forest cover was noticed between 1975 and 2009, and with current rate of deforestation, a forest area of 4,563.34 km2 will be lost by 2028. The annual rate of deforestation worked out to be 0.35 and 0.78% during 1975-1990 and 1990-2009 respectively. Bamboo forest increased by 24.98% between 1975 and 2009 due to opening up of the forests. Forests in Kokrajhar, Barpeta, Darrang, Sonitpur, and Dhemaji districts in Assam were noticed to be worst-affected while Lower Subansiri, West and East Siang, Dibang Valley, Lohit and Changlang in Arunachal Pradesh were severely affected. Among different forest types, the maximum loss was seen in case of sal forest (37.97%) between 1975 and 2009 and is expected to deplete further to 60.39% by 2028. The tropical moist deciduous forest was the next category, which decreased from 5,208.11 km2 to 3,447.28 (33.81%) during same period with further chances of depletion to 2,288.81 km2 (56.05%) by 2028. It noted progressive loss of forests in the study area between 1975 and 2009 through 1990 and predicted that, unless checked, the area is in for further depletion of the invaluable climax forests in the region, especially sal and moist deciduous forests. The exercise demonstrated high potential of remote sensing and geographic information system for forest ecosystem dynamics assessment and the efficacy of CAMM to predict the forest cover change.

Foliage efficiency of forest-forming species in the climatic gradients of Eurasia

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V. A. Usoltsev

2017-08-01

Full Text Available The paperis of the scientific area of biogeography and devoted to a new aspect in the study of biological productivity of forest ecosystems on a geographical basis, expressed indirectly by climate parameters, namely, the foliage efficiency that until now is not investigated at the global level. Foliage efficiency is the ratio of net primary production (NPP to foliage biomass and is expressed in relative units. Some features of change of foliage efficiency of vicarious forest-forming species in Eurasian transcontinental gradients are showed for the first time using the voluminous factual material. The set of published biomass and NPP data (t/ha obtained in a number of 2192 plots is compiled. Using multiple regression analysis technique, the statistically significant changes in foliage efficiency values according to two transcontinental gradients, namely by zonal belts and continentality of climate, are stated for each forest-forming species. The species-specificity of age dynamics of stem volume and foliage efficiency is shown. It is monotonically decreased almost for all tree species in the following order: spruce and fir, pine, birch, oak, larch and aspen-poplar. When climate continentality increasing, foliage efficiency values of mature forests is dropping, most intensively in pines, less intensive in deciduous forests and virtually no changes in spruce-fir communities. In zonal gradient from the northern temperate to the subequatorial belt, foliage efficiency of deciduous species decreases, but it of the evergreen spruce and pine increases in the same direction. One of the possible causes of these opposite zonal trends of foliage efficiency in evergreen and deciduous species consists in different conditions of physiological processes in the year cycle, in particular, in year-round assimilates accumulation in the first and seasonal one in the second.

Dominance of legume trees alters nutrient relations in mixed species forest restoration plantings within seven years

Science.gov (United States)

Ilyas Siddique; Vera Lex Engel; David Lamb; Gabriela B. Nardoto; Jean P.H.B. Ometto; Luiz A. Martinelli; Susanne. Schmidt

2008-01-01

Failures in reforestation are often attributed to nutrient limitation for tree growth. We compared tree performance and nitrogen and phosphorus relations in adjacent mixed-species plantings of contrasting composition, established for forest restoration on Ultisol soil, originally covered by tropical semi-deciduous Atlantic Forest in Southeast Brazil. Nutrient relations...

Mathematical model of 137Cs dynamics in the deciduous forest

International Nuclear Information System (INIS)

Mamikhin, S.V.; Klyashtorin, A.L.

1999-01-01

A mathematical model of 137 Cs behaviour in the forest ecosystem is presented. The behaviour of this radionuclide is assumed to obey the same regularities as the behaviour of its stable chemical analogue, potassium. Radionuclide dynamics are considered in parallel with the dynamics of the phytomass. Radionuclides contained in the vegetation are pooled into two basic compartments: external and internal contamination, with separate analysis of each. The model was verified using the data obtained in the 30-km zone of the Chernobyl NPP in 1986-1994. The algorithm described was found to be the most efficient in terms of 137 Cs behaviour in the forest environments

Evaluating the effect of alternative carbon allocation schemes in a land surface model (CLM4.5) on carbon fluxes, pools, and turnover in temperate forests

Science.gov (United States)

Montané, Francesc; Fox, Andrew M.; Arellano, Avelino F.; MacBean, Natasha; Alexander, M. Ross; Dye, Alex; Bishop, Daniel A.; Trouet, Valerie; Babst, Flurin; Hessl, Amy E.; Pederson, Neil; Blanken, Peter D.; Bohrer, Gil; Gough, Christopher M.; Litvak, Marcy E.; Novick, Kimberly A.; Phillips, Richard P.; Wood, Jeffrey D.; Moore, David J. P.

2017-09-01

How carbon (C) is allocated to different plant tissues (leaves, stem, and roots) determines how long C remains in plant biomass and thus remains a central challenge for understanding the global C cycle. We used a diverse set of observations (AmeriFlux eddy covariance tower observations, biomass estimates from tree-ring data, and leaf area index (LAI) measurements) to compare C fluxes, pools, and LAI data with those predicted by a land surface model (LSM), the Community Land Model (CLM4.5). We ran CLM4.5 for nine temperate (including evergreen and deciduous) forests in North America between 1980 and 2013 using four different C allocation schemes: i. dynamic C allocation scheme (named "D-CLM4.5") with one dynamic allometric parameter, which allocates C to the stem and leaves to vary in time as a function of annual net primary production (NPP); ii. an alternative dynamic C allocation scheme (named "D-Litton"), where, similar to (i), C allocation is a dynamic function of annual NPP, but unlike (i) includes two dynamic allometric parameters involving allocation to leaves, stem, and coarse roots; iii.-iv. a fixed C allocation scheme with two variants, one representative of observations in evergreen (named "F-Evergreen") and the other of observations in deciduous forests (named "F-Deciduous"). D-CLM4.5 generally overestimated gross primary production (GPP) and ecosystem respiration, and underestimated net ecosystem exchange (NEE). In D-CLM4.5, initial aboveground biomass in 1980 was largely overestimated (between 10 527 and 12 897 g C m-2) for deciduous forests, whereas aboveground biomass accumulation through time (between 1980 and 2011) was highly underestimated (between 1222 and 7557 g C m-2) for both evergreen and deciduous sites due to a lower stem turnover rate in the sites than the one used in the model. D-CLM4.5 overestimated LAI in both evergreen and deciduous sites because the leaf C-LAI relationship in the model did not match the observed leaf C

Contrasting ozone sensitivity in related evergreen and deciduous shrubs

International Nuclear Information System (INIS)

Calatayud, Vicent; Marco, Francisco; Cervero, Julia; Sanchez-Pena, Gerardo; Sanz, Maria Jose

2010-01-01

Plant responses to enhanced ozone levels have been studied in two pairs of evergreen-deciduous species (Pistacia terebinthus vs. P. lentiscus; Viburnum lantana vs. V. tinus) in Open Top Chambers. Ozone induced widespread visible injury, significantly reduced CO 2 assimilation and stomatal conductance (g s ), impaired Rubisco efficiency and regeneration capacity (V c,max, J max ) and altered fluorescence parameters only in the deciduous species. Differences in stomatal conductance could not explain the observed differences in sensitivity. In control plants, deciduous species showed higher superoxide dismutase (SOD) activity than their evergreen counterparts, suggesting metabolic differences that could make them more prone to redox imbalances. Ozone induced increases in SOD and/or peroxidase activities in all the species, but only evergreens were able to cope with the oxidative stress. The relevancy of these results for the effective ozone flux approach and for the current ozone Critical Levels is also discussed. - Mediterranean evergreen shrubs have a constitutively higher capacity to tolerate ozone stress than their deciduous relatives.

Soil seed banks along elevational gradients in tropical, subtropical and subalpine forests in Yunnan Province, southwest China

Institute of Scientific and Technical Information of China (English)

Xiaqin Luo; Min Cao; Min Zhang; Xiaoyang Song; Jieqiong Li; Akihiro Nakamura; Roger Kitching

2017-01-01

Soil seed banks are a vital part of ecosystems and influence community dynamics and regeneration.Although soil seed banks in different habitats have been reported,how soil seed banks vary with elerational gradients in different climatic zones is still unknown.This paper investigates seed density,species composition and nonconstituent species of forest soil seed banks in Yunnan Province,southwest China.Similarity between the soil seed bank and standing vegetation was also examined.We collected soil samples from sites spanning 12 elevations in tropical rain forests,subtropical evergreen broadleaved forests and subalpine coniferous forests,and transported them to a glasshouse for germination trials for species identification.The soil seed banks of tropical and subtropical forests had much higher seed densities and species richness than those of subalpine forests.Seeds of woody species dominated the soil seed banks of tropical and subtropical forests,while herbs dominated those of subalpine forests.The nonconstituent species in the soil seed banks were all herbs and were most abundant in tropical forests,followed by subtropical forests but were completely absent from subalpine forests.

Soil seed banks along elevational gradients in tropical, subtropical and subalpine forests in Yunnan Province, southwest China

Directory of Open Access Journals (Sweden)

Xiaqin Luo

2017-10-01

Full Text Available Soil seed banks are a vital part of ecosystems and influence community dynamics and regeneration. Although soil seed banks in different habitats have been reported, how soil seed banks vary with elevational gradients in different climatic zones is still unknown. This paper investigates seed density, species composition and nonconstituent species of forest soil seed banks in Yunnan Province, southwest China. Similarity between the soil seed bank and standing vegetation was also examined. We collected soil samples from sites spanning 12 elevations in tropical rain forests, subtropical evergreen broad-leaved forests and subalpine coniferous forests, and transported them to a glasshouse for germination trials for species identification. The soil seed banks of tropical and subtropical forests had much higher seed densities and species richness than those of subalpine forests. Seeds of woody species dominated the soil seed banks of tropical and subtropical forests, while herbs dominated those of subalpine forests. The nonconstituent species in the soil seed banks were all herbs and were most abundant in tropical forests, followed by subtropical forests but were completely absent from subalpine forests.

Differences in ecosystem carbon distribution and nutrient cycling linked to forest tree species composition in a mid-successional boreal forest

Science.gov (United States)

Melvin, April M.; Mack, Michelle C.; Johnstone, Jill F.; McGuire, A. David; Genet, Helene; Schuur, Edward A.G.

2015-01-01

In the boreal forest of Alaska, increased fire severity associated with climate change is expanding deciduous forest cover in areas previously dominated by black spruce (Picea mariana). Needle-leaf conifer and broad-leaf deciduous species are commonly associated with differences in tree growth, carbon (C) and nutrient cycling, and C accumulation in soils. Although this suggests that changes in tree species composition in Alaska could impact C and nutrient pools and fluxes, few studies have measured these linkages. We quantified C, nitrogen, phosphorus, and base cation pools and fluxes in three stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a single fire event in 1958. Paper birch consistently displayed characteristics of more rapid C and nutrient cycling, including greater aboveground net primary productivity, higher live foliage and litter nutrient concentrations, and larger ammonium and nitrate pools in the soil organic layer (SOL). Ecosystem C stocks (aboveground + SOL + 0–10 cm mineral soil) were similar for the two species; however, in black spruce, 78% of measured C was found in soil pools, primarily in the SOL, whereas aboveground biomass dominated ecosystem C pools in birch forest. Radiocarbon analysis indicated that approximately one-quarter of the black spruce SOL C accumulated prior to the 1958 fire, whereas no pre-fire C was observed in birch soils. Our findings suggest that tree species exert a strong influence over C and nutrient cycling in boreal forest and forest compositional shifts may have long-term implications for ecosystem C and nutrient dynamics.

Influence of spring phenology on seasonal and annual carbon balance in two contrasting New England forests

Science.gov (United States)

Andrew D. Richardson; David Y. Hollinger; D. Bryan Dail; John T. Lee; J. William Munger; John O' Keefe

2009-01-01

Spring phenology is thought to exert a major influence on the carbon (C) balance of temperate and boreal ecosystems. We investigated this hypothesis using four spring onset phenological indicators in conjunction with surface-atmosphere CO2 exchange data from the conifer-dominated Howland Forest and deciduous-dominated Harvard Forest AmeriFlux...

Occurrence of culturable soil fungi in a tropical moist deciduous forest Similipal Biosphere Reserve, Odisha, India.

Science.gov (United States)

Jena, Santanu K; Tayung, Kumanand; Rath, Chandi C; Parida, Debraj

2015-03-01

Similipal Biosphere Reserve (SBR) is a tropical moist deciduous forest dominated by the species Shorea robusta . To the best of our knowledge their rich biodiversity has not been explored in term of its microbial wealth. In the present investigation, soil samples were collected from ten selected sites inside SBR and studied for their physicochemical parameters and culturable soil fungal diversity. The soil samples were found to be acidic in nature with a pH ranging from of 5.1-6.0. Highest percentage of organic carbon and moisture content were observed in the samples collected from the sites, Chahala-1 and Chahala-2. The plate count revealed that fungal population ranged from 3.6 × 10 (4) -2.1 × 10 (5) and 5.1 × 10 (4) -4.7 × 10 (5) cfu/gm of soil in summer and winter seasons respectively. The soil fungus, Aspergillus niger was found to be the most dominant species and Species Important Values Index (SIVI) was 43.4 and 28.6 in summer and winter seasons respectively. Among the sites studied, highest fungal diversity indices were observed during summer in the sites, Natto-2 and Natto-1. The Shannon-Wiener and Simpson indices in these two sites were found to be 3.12 and 3.022 and 0.9425 and 0.9373 respectively. However, the highest Fisher's alpha was observed during winter in the sites Joranda, Natto-2, Chahala-1 and Natto-1 and the values were 3.780, 3.683, 3.575 and 3.418 respectively. Our investigation revealed that, fungal population was dependent on moisture and organic carbon (%) of the soil but its diversity was found to be regulated by sporulating species like Aspergillus and Penicillium.

Occurrence of culturable soil fungi in a tropical moist deciduous forest Similipal Biosphere Reserve, Odisha, India

Science.gov (United States)

Jena, Santanu K.; Tayung, Kumanand; Rath, Chandi C.; Parida, Debraj

2015-01-01

Similipal Biosphere Reserve (SBR) is a tropical moist deciduous forest dominated by the species Shorea robusta . To the best of our knowledge their rich biodiversity has not been explored in term of its microbial wealth. In the present investigation, soil samples were collected from ten selected sites inside SBR and studied for their physicochemical parameters and culturable soil fungal diversity. The soil samples were found to be acidic in nature with a pH ranging from of 5.1–6.0. Highest percentage of organic carbon and moisture content were observed in the samples collected from the sites, Chahala-1 and Chahala-2. The plate count revealed that fungal population ranged from 3.6 × 10 4 –2.1 × 10 5 and 5.1 × 10 4 –4.7 × 10 5 cfu/gm of soil in summer and winter seasons respectively. The soil fungus, Aspergillus niger was found to be the most dominant species and Species Important Values Index (SIVI) was 43.4 and 28.6 in summer and winter seasons respectively. Among the sites studied, highest fungal diversity indices were observed during summer in the sites, Natto-2 and Natto-1. The Shannon-Wiener and Simpson indices in these two sites were found to be 3.12 and 3.022 and 0.9425 and 0.9373 respectively. However, the highest Fisher’s alpha was observed during winter in the sites Joranda, Natto-2, Chahala-1 and Natto-1 and the values were 3.780, 3.683, 3.575 and 3.418 respectively. Our investigation revealed that, fungal population was dependent on moisture and organic carbon (%) of the soil but its diversity was found to be regulated by sporulating species like Aspergillus and Penicillium . PMID:26221092

Occurrence of culturable soil fungi in a tropical moist deciduous forest Similipal Biosphere Reserve, Odisha, India

Directory of Open Access Journals (Sweden)

Santanu K. Jena

2015-03-01

Full Text Available Similipal Biosphere Reserve (SBR is a tropical moist deciduous forest dominated by the species Shorea robusta. To the best of our knowledge their rich biodiversity has not been explored in term of its microbial wealth. In the present investigation, soil samples were collected from ten selected sites inside SBR and studied for their physicochemical parameters and culturable soil fungal diversity. The soil samples were found to be acidic in nature with a pH ranging from of 5.1–6.0. Highest percentage of organic carbon and moisture content were observed in the samples collected from the sites, Chahala-1 and Chahala-2. The plate count revealed that fungal population ranged from 3.6 × 104–2.1 × 105 and 5.1 × 104–4.7 × 105 cfu/gm of soil in summer and winter seasons respectively. The soil fungus, Aspergillus niger was found to be the most dominant species and Species Important Values Index (SIVI was 43.4 and 28.6 in summer and winter seasons respectively. Among the sites studied, highest fungal diversity indices were observed during summer in the sites, Natto-2 and Natto-1. The Shannon-Wiener and Simpson indices in these two sites were found to be 3.12 and 3.022 and 0.9425 and 0.9373 respectively. However, the highest Fisher’s alpha was observed during winter in the sites Joranda, Natto-2, Chahala-1 and Natto-1 and the values were 3.780, 3.683, 3.575 and 3.418 respectively. Our investigation revealed that, fungal population was dependent on moisture and organic carbon (% of the soil but its diversity was found to be regulated by sporulating species like Aspergillus and Penicillium.

SRTM-DEM AND LANDSAT ETM+ DATA FOR MAPPING TROPICAL DRY FOREST COVER AND BIODIVERSITY ASSESSMENT IN NICARAGUA

OpenAIRE

Brett G. Dickson; Carol L. Chambers; Sarah M. Otterstrom; Suzanne E. Hagell; Steven E. Sesnie

2008-01-01

Tropical dry and deciduous forest comprises as much as 42% of the world’s tropical forests, but hasreceived far less attention than forest in wet tropical areas. Land use change threatens to greatly reducethe extent of dry forest that is known to contain high levels of plant and animal diversity. Forest fragmentationmay further endanger arboreal mammals that play principal role in the dispersal of large seeded fruits, plantcommunity assembly and diversity in these systems. Data on the spatial...

Fine Root Growth Phenology, Production, and Turnover in a Northern Hardwood Forest Ecosystem

Science.gov (United States)

Dudley J. Raynal

1994-01-01

A large part of the nutrient flux in deciduous forests is through fine root turnover, yet this process is seldom measured. As part of a nutrient cycling study, fine root dynamics were studied for two years at Huntington Forest in the Adirondack Mountain region of New York, USA. Root growth phenology was characterized using field rhizotrons, three methods were used to...

Atmospheric Direct Uptake and Long-term Fate of Radiocesium in Trees after the Fukushima Nuclear Accident

Science.gov (United States)

Mahara, Yasunori; Ohta, Tomoko; Ogawa, Hideki; Kumata, Atsushi

2014-11-01

Large areas of forests were radioactively contaminated by the Fukushima nuclear accident of 2011, and forest decontamination is now an important problem in Japan. However, whether trees absorb radioactive fallout from soil via the roots or directly from the atmosphere through the bark and leaves is unclear. We measured the uptake of radiocesium by trees in forests heavily contaminated by the Fukushima nuclear accident. The radiocesium concentrations in sapwood of two tree species, the deciduous broadleaved konara (Quercus serrata) and the evergreen coniferous sugi (Cryptomeria japonica), were higher than that in heartwood. The concentration profiles showed anomalous directionality in konara and non-directionality in sugi, indicating that most radiocesium in the tree rings was directly absorbed from the atmosphere via bark and leaves rather than via roots. Numerical modelling shows that the maximum 137Cs concentration in the xylem of konara will be achieved 28 years after the accident. Conversely, the values for sugi will monotonously decrease because of the small transfer factor in this species. Overall, xylem 137Cs concentrations will not be affected by root uptake if active root systems occur 10 cm below the soil.

Regeneration of forest phytocoenoses after various agricultural land use practices in the conditions of middle taiga subzone

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V. A. Karpin

2017-12-01

Full Text Available The process of forest cover regeneration after the cessation of human impact was considered. The study area was situated in the southern part of the Kenozersky National Park, Arkhangelsk Oblast. This area has 500 years of agricultural land use history. The territory features a complete spectrum of land at some point used for agricultural production: from sites currently in active use to fully recovered tree stands aged 120–140 years. The reforestation process was considered separately for each of the following land uses: slash-and-burn, multipurpose small-patch, and arable-grassland types, which differ considerably in impact intensity, duration, and degree of disturbance of the forest environment. The course of forest regeneration successions was found to depend on the type of preceding land use. The time required for the forest communities in slash-and-burn sites to recover to their original state is 120–140 years, and the succession involves the deciduous stage. Multipurpose small-patch use left the forest environment more profoundly modified. Eventually, a majority of these sites are now occupied by more productive, although undistinguishable from the original, coniferous-deciduous stands. Some factors have been detected that may lead to the formation in such sites of low-productivity self-regenerating plant communities dominated by deciduous species, which can persist there for an indefinitely long time unless relevant actions are taken. Arable-grassland land use considerably inhibits the regeneration of the forest cover typical of middle taiga, because there forms a thick sod layer. It was only in some grassland patches, where the impact stopped 5–10 years ago, that coniferous species, namely pine, were successfully regenerating.

Evaluating Ammonia Deposition Rates for Deciduous Forest using Measurements and Modelling

DEFF Research Database (Denmark)

Hansen, Kristina; Geels, Camilla; Hertel, Ole

). However, there are relatively few datasets of atmospheric NH3 fluxes available for forests which can contribute verifying model results. The atmospheric dry deposition of NH3 for the beech (Fagus sylvatica) forest, Lille Bøgeskov, in Sorø, Denmark, is investigated using the high resolution...... these impacts, quantifying the magnitude of the NH3 flux in the biosphere atmosphere system is essential. Model simulations using the Danish Ammonia Modelling System (DAMOS) have recently indicated that particular forest ecosystems are exposed to critical load exceedances of N (Geels et al., not yet submitted......-agricultural areas (Skjøth et al. 2011, ACPD). New atmospheric NH3 flux measurements for Lille Bøgeskov have been conducted throughout 2011 and these data are presented and discussed in relation to the 2010 data of atmospheric NH3. Future studies aim to improve the description of dry deposition of NH3 for vegetative...

Molecular characterization of soil bacterial community in a perhumid, low mountain forest.

Science.gov (United States)

Lin, Yu-Te; Whitman, William B; Coleman, David C; Chih-Yu, Chiu

2011-01-01

Forest disturbance often results in changes in soil properties and microbial communities. In the present study, we characterized a soil bacterial community subjected to disturbance using 16S rRNA gene clone libraries. The community was from a disturbed broad-leaved, low mountain forest ecosystem at Huoshaoliao (HSL) located in northern Taiwan. This locality receives more than 4,000 mm annual precipitation, one of the highest precipitations in Taiwan. Based on the Shannon diversity index, Chao1 estimator, richness and rarefaction curve analysis, the bacterial community in HSL forest soils was more diverse than those previously investigated in natural and disturbed forest soils with colder or less humid weather conditions. Analysis of molecular variance also revealed that the bacterial community in disturbed soils significantly differed from natural forest soils. Most of the abundant operational taxonomic units (OTUs) in the disturbed soil community at HSL were less abundant or absent in other soils. The disturbances influenced the composition of bacterial communities in natural and disturbed forests and increased the diversity of the disturbed forest soil community. Furthermore, the warmer and humid weather conditions could also increase community diversity in HSL soils.

Mapping forests in monsoon Asia with ALOS PALSAR 50-m mosaic images and MODIS imagery in 2010.

Science.gov (United States)

Qin, Yuanwei; Xiao, Xiangming; Dong, Jinwei; Zhang, Geli; Roy, Partha Sarathi; Joshi, Pawan Kumar; Gilani, Hammad; Murthy, Manchiraju Sri Ramachandra; Jin, Cui; Wang, Jie; Zhang, Yao; Chen, Bangqian; Menarguez, Michael Angelo; Biradar, Chandrashekhar M; Bajgain, Rajen; Li, Xiangping; Dai, Shengqi; Hou, Ying; Xin, Fengfei; Moore, Berrien

2016-02-11

Extensive forest changes have occurred in monsoon Asia, substantially affecting climate, carbon cycle and biodiversity. Accurate forest cover maps at fine spatial resolutions are required to qualify and quantify these effects. In this study, an algorithm was developed to map forests in 2010, with the use of structure and biomass information from the Advanced Land Observation System (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) mosaic dataset and the phenological information from MODerate Resolution Imaging Spectroradiometer (MOD13Q1 and MOD09A1) products. Our forest map (PALSARMOD50 m F/NF) was assessed through randomly selected ground truth samples from high spatial resolution images and had an overall accuracy of 95%. Total area of forests in monsoon Asia in 2010 was estimated to be ~6.3 × 10(6 )km(2). The distribution of evergreen and deciduous forests agreed reasonably well with the median Normalized Difference Vegetation Index (NDVI) in winter. PALSARMOD50 m F/NF map showed good spatial and areal agreements with selected forest maps generated by the Japan Aerospace Exploration Agency (JAXA F/NF), European Space Agency (ESA F/NF), Boston University (MCD12Q1 F/NF), Food and Agricultural Organization (FAO FRA), and University of Maryland (Landsat forests), but relatively large differences and uncertainties in tropical forests and evergreen and deciduous forests.

FOREST DISTRIBUTION ON THE CENTRAL RUSSIAN UPLAND: HISTORICAL PERSPECTIVE

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Maria V. Arkhipova

2014-01-01

Full Text Available We studied the change of forestland in the Central Russian Upland within the deciduous forest, forest-steppe, and steppe zones using old maps (XVIII-XX cc. and current satellite images. The forest distribution within the Central Russian Upland has been relatively stable during the last 220 years. On average, the decrease in the forested area was small. However, we identified significant changes in certain regions. In the southern part of CRU, the significant increase of the forested land is caused by the forest protection of abatis woodland and afforestation. During the last 100 years, reforestation took place mainly in the Oka basin due to both afforestation and natural reforestation. New forests appeared generally in ravines within all zones. The analysis of the abatis forests changes from the XVIII to XX cc. allowed us to identify forested area within the Central Russian Upland prior to active development.

Interpretation of Upper-Storey Canopy Area in Subtropical Broad-leaved Forests in Okinawa Island Using Laser Scanning Data

International Nuclear Information System (INIS)

Noor Janatun Naim Jemali; Shiba, M.; Azita Ahmad Zawawi; Noor Janatun Naim Jemali

2015-01-01

Conventional forest inventory practice took huge of effort, and is time- and cost- consuming. With the aid of remote sensing technology by light detection and ranging (LiDAR), those unbearable factors could be minimized. LiDAR is able to capture forest characteristic information and is well known for estimating forest structure accurately in many studies. Forest monitoring related to forest resource inventory (FRI) becomes more effective by utilizing LiDAR data and it is tremendously useful, especially to distinguish information on density, growth and distribution of trees in a selected area. In this study, LiDAR data was utilized aimed to delineate crown cover and estimate upper-storey canopy area in Yambaru Forest using object-based segmentation and classification techniques. Agreement between field survey and LiDAR data analysis showed that only 33.7 % of upper-storey canopy area was successfully delineated. The low accuracy level of canopy detection in Yambaru Forest area was expected mainly due to tree structure, density and topographic condition. (author)

Litterfall, litter decomposition and nitrogen mineralization in old-growth evergreen and secondary deciduous Nothofagus forests in south-central Chile Aporte, descomposición de hojarasca y mineralización de nitrógeno en bosques siempreverdes de antiguo crecimiento y bosques secundarios deciduos, centro-sur de Chile

Directory of Open Access Journals (Sweden)

JEROEN STAELENS

2011-03-01

Full Text Available South Chilean forest ecosystems represent one of the largest areas of old-growth temperate rainforests remaining in the Southern hemisphere and have a high ecological value, but suffer from deforestation, invasion by exotic species, fragmentation, and increasing atmospheric nitrogen (N deposition. To support sustainable forest management, more knowledge is required on nutrient cycling of these ecosystems. Therefore, a descriptive study of nutrient dynamics was done in four Valdivian rainforests in the lower Andes range of south Chile: old-growth and altered evergreen stands and unmanaged and managed secondary deciduous stands. Time series were measured for (i mass (four year and nutrient content (N, K, Ca, and Mg; one year of litterfall, (ii decomposition and nutrient dynamics (N, C, K, Ca, Mg, and P; one year of leaf litter and Saxegothaea conspicua bark litter, and (iii in situ topsoil net N mineralization (one year. Litterfall in the four stands ranged from 3.5 to 5.8 ton ha-1 yr-1, was temporarily lower in the managed than in the unmanaged deciduous stand and had a different seasonality in the evergreen stands than in the deciduous stands. Leaf litter decomposed faster (on average 32 % mass loss after one year than bark litter (8 % but without significant differences between leaf litter types. Net N in evergreen leaf litter decreased during decomposition but increased in deciduous leaf litter. Net soil N mineralization was fastest in the pristine evergreen stand, intermediate in the deciduous stands and slowest in the altered evergreen forest. Given the absence of replicated stands, the definite impact of forest type or management regime on the internal nutrient cycling cannot be demonstrated. Nevertheless, the results suggest that management can affect nutrient turnover by altering species composition and forest structure, while recent (five years selective logging in secondary deciduous forest did not affect litter decomposition or N

Wetland survey of the X-10 Bethel Valley and Melton Valley groundwater operable units at Oak Ridge National Labortory Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Rosensteel, B.A.

1996-03-01

Executive Order 11990, Protection of Wetlands, (May 24, 1977) requires that federal agencies avoid, to the extent possible, adverse impacts associated with the destruction and modification of wetlands and that they avoid direct and indirect support of wetlands development when there is a practicable alternative. In accordance with Department of Energy (DOE) Regulations for Compliance with Floodplains and Wetlands Environmental Review Requirements (Subpart B, 10 CFR 1022.11), surveys for wetland presence or absence were conducted in both the Melton Valley and the Bethel Valley Groundwater Operable Units (GWOU) on the DOE Oak Ridge Reservation (ORR) from October 1994 through September 1995. As required by the Energy and Water Development Appropriations Act of 1992, wetlands were identified using the criteria and methods set forth in the Wetlands Delineation Manual (Army Corps of Engineers, 1987). Wetlands were identified during field surveys that examined and documented vegetation, soils, and hydrologic evidence. Most of the wetland boundary locations and wetland sizes are approximate. Boundaries of wetlands in Waste Area Grouping (WAG) 2 and on the former proposed site of the Advanced Neutron Source in the upper Melton Branch watershed were located by civil survey during previous wetland surveys; thus, the boundary locations and areal sizes in these areas are accurate. The wetlands were classified according to the system developed by Cowardin et al. (1979) for wetland and deepwater habitats of the United States. A total of 215 individual wetland areas ranging in size from 0.002 ha to 9.97 ha were identified in the Bethel Valley and Melton Valley GWOUs. The wetlands are classified as palustrine forested broad-leaved deciduous (PFO1), palustrine scrub-shrub broad-leaved deciduous (PSS1), and palustrine persistent emergent (PEM1)

Floristic-functional variation of tree component along an altitudinal gradient in araucaria forest areas, in Southern Brazil.

Science.gov (United States)

Soboleski, Vanessa F; Higuchi, Pedro; Silva, Ana Carolina DA; Silva, Mariele A F DA; Nunes, Amanda S; Loebens, Rodineli; Souza, Karine DE; Ferrari, Jheniffer; Lima, Carla L; Kilca, Ricardo V

2017-01-01

We aimed to investigate the taxonomic and functional variations of tree component of Araucaria Forest (AF) areas located along an altitudinal gradient (700, 900 and 1,600 m asl), in the southern region of Brazil. The functional traits determined were leaf area, specific leaf area, wood density, maximum potential height and dispersal syndromes and deciduousness. The data were analyzed through a functional and taxonomic dissimilarity dendrograms, community-weighted mean trait values, parametric and nonparametric tests, and Principal Component Analysis. The largest floristic-structural similarity was observed between the lower altitude areas (700 and 900 m asl), whose Bray-Curtis distance was 0.63. The area at 700 m asl was characterized by a predominance of deciduous and semi-deciduous species, with a high number of self- and wind-dispersed species, whereas the area at 1,600 m asl exhibited a predominance of animal-dispersed and evergreen species. It was also observed that there were significant variations for leaf traits, basic wood density and maximum potential height. Over all altitudinal gradient, the ordinations indicated that there was no evidence of functional differentiation among dispersal and deciduousness groups. In conclusion, the evaluated Araucaria Forest areas presented high floristic-functional variation of the tree component along the altitudinal gradient.

Contrasting ozone sensitivity in related evergreen and deciduous shrubs

Energy Technology Data Exchange (ETDEWEB)

Calatayud, Vicent, E-mail: vicent@ceam.e [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain); Marco, Francisco; Cervero, Julia [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain); Sanchez-Pena, Gerardo [SPCAN, Dir. Gral. de Medio Natural y Politica Forestal, Ministerio de Medio Ambiente, y Medio Rural y Marino, Rios Rosas 24, 28003 Madrid (Spain); Sanz, Maria Jose [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain)

2010-12-15

Plant responses to enhanced ozone levels have been studied in two pairs of evergreen-deciduous species (Pistacia terebinthus vs. P. lentiscus; Viburnum lantana vs. V. tinus) in Open Top Chambers. Ozone induced widespread visible injury, significantly reduced CO{sub 2} assimilation and stomatal conductance (g{sub s}), impaired Rubisco efficiency and regeneration capacity (V{sub c,max,}J{sub max}) and altered fluorescence parameters only in the deciduous species. Differences in stomatal conductance could not explain the observed differences in sensitivity. In control plants, deciduous species showed higher superoxide dismutase (SOD) activity than their evergreen counterparts, suggesting metabolic differences that could make them more prone to redox imbalances. Ozone induced increases in SOD and/or peroxidase activities in all the species, but only evergreens were able to cope with the oxidative stress. The relevancy of these results for the effective ozone flux approach and for the current ozone Critical Levels is also discussed. - Mediterranean evergreen shrubs have a constitutively higher capacity to tolerate ozone stress than their deciduous relatives.

[Impacts of forest and precipitation on runoff and sediment in Tianshui watershed and GM models].

Science.gov (United States)

Ouyang, H

2000-12-01

This paper analyzed the impacts of foret stand volume and precipitation on annual erosion modulus, mean sediment, maximum sediment, mean runoff, maximum runoff, minimum runoff, mean water level, maximum water level and minimum water level in Tianshui watershed, and also analyzed the effect of the variation of forest stand volume on monthly mean runoff, minimum runoff and mean water level. The dynamic models of grey system GM(1, N) were constructed to simulate the changes of these hydrological elements. The dynamic GM models on the impact of stand volumes of different forest types(Chinese fir, masson pine and broad-leaved forests) with different age classes(young, middle-aged, mature and over-mature) and that of precipitation on the hydrological elements were also constructed, and their changes with time were analyzed.

[Observation of osteoclasts on the root surface during human deciduous teeth resorption].

Science.gov (United States)

Bao, Xiang-jun; Liang, Xing; Chen, Ming; Wang, Hang; Xie, Zhi-gang; Yang, Xiao-yu

2004-08-01

To observe osteoclasts on the resorbing surface of human deciduous teeth. After fixing the collected deciduous teeth, we prepared the tooth slices without decalcification, treated them with HE and TRAP dyestuff, and observed the osteoclasts under light and scanning electron microscope. There were large quantity of various forms of overlapping and huge osteoclasts with many nuclei and silk-like protuberances on the resorbing surface of deciduous teeth. The multinucleated osteoclasts align on the surface of coarse dentin. On the resorbing surface of human deciduous teeth there are large amount of osteoclasts which can be used as a source of studying human osteoclast.

Assessment of Different Remote Sensing Data for Forest Structural Attributes Estimation in the Hyrcanian forests

Energy Technology Data Exchange (ETDEWEB)

Nourian, N.; Shataee-Joibary, S.; Mohammadi, J.

2016-07-01

Aim of the study: The objective of the study was the comparative assessment of various spatial resolutions of optical satellite imagery including Landsat-TM, ASTER, and Quickbird data to estimate the forest structure attributes of Hyrcanian forests, Golestan province, northernIran. Material and methods: The 112 square plots with area of0.09 ha were measured using a random cluster sampling method and then stand volume, basal area, and tree stem density were computed using measured data. After geometric and atmospheric corrections of images, the spectral attributes from original and different synthetic bands were extracted for modelling. The statistical modelling was performed using CART algorithm. Performance assessment of models was examined using the unused validation plots by RMSE and bias measures. Main Results: The results showed that model of Quickbird data for stand volume, basal area, and tree stem density had a better performance compared to ASTER and TM data. However, estimations by ASTER and TM imagery had slightly similar results for all three parameters. Research highlights: This study exposed that the high-resolution satellite data are more useful for forest structure attributes estimation in the Hyrcanian broadleaves forests compared with medium resolution images without consideration of images costs. However, regarding to be free of the most medium resolution data such as ASTER and TM,ETM+ or OLI images, these data can be used with slightly similar results. (Author)

Folate Deficiency Could Restrain Decidual Angiogenesis in Pregnant Mice

Directory of Open Access Journals (Sweden)

Yanli Li

2015-08-01

Full Text Available The mechanism of birth defects induced by folate deficiency was focused on mainly in fetal development. Little is known about the effect of folate deficiency on the maternal uterus, especially on decidual angiogenesis after implantation which establishes vessel networks to support embryo development. The aim of this study was to investigate the effects of folate deficiency on decidual angiogenesis. Serum folate levels were measured by electrochemiluminescence. The status of decidual angiogenesis was examined by cluster designation 34 (CD34 immunohistochemistry and the expression of angiogenic factors, including vascular endothelial growth factor A (VEGFA, placental growth factor (PLGF, and VEGF receptor 2 (VEGFR2 were also tested. Serum levels of homocysteine (Hcy, follicle stimulating hormone (FSH, luteinizing hormone (LH, prolactin (PRL, progesterone (P4, and estradiol (E2 were detected by Enzyme-linked immunosorbent assay. The folate-deficient mice had a lower folate level and a higher Hcy level. Folate deficiency restrained decidual angiogenesis with significant abnormalities in vascular density and the enlargement and elongation of the vascular sinus. It also showed a reduction in the expressions of VEGFA, VEGFR2, and PLGF. In addition, the serum levels of P4, E2, LH, and PRL were reduced in folate-deficient mice, and the expression of progesterone receptor (PR and estrogen receptor α (ERα were abnormal. These results indicated that folate deficiency could impaire decidual angiogenesis and it may be related to the vasculotoxic properties of Hcy and the imbalance of the reproductive hormone.

Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

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M. Zhang

2010-02-01

Full Text Available Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS and a subtropical evergreen broad-leaved forest at Dinghushan (DHS, based on the flux data obtained during June–August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (P_ec,max at CBS under cloudy skies during mid-growing season (from June to August increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, P_ec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (k_t ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when k_t exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP and greater increase in ecosystem respiration (R_e at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in

Quantifying the Accuracy of Digital Hemispherical Photography for Leaf Area Index Estimates on Broad-Leaved Tree Species.

Science.gov (United States)

Gilardelli, Carlo; Orlando, Francesca; Movedi, Ermes; Confalonieri, Roberto

2018-03-29

Digital hemispherical photography (DHP) has been widely used to estimate leaf area index (LAI) in forestry. Despite the advancement in the processing of hemispherical images with dedicated tools, several steps are still manual and thus easily affected by user's experience and sensibility. The purpose of this study was to quantify the impact of user's subjectivity on DHP LAI estimates for broad-leaved woody canopies using the software Can-Eye. Following the ISO 5725 protocol, we quantified the repeatability and reproducibility of the method, thus defining its precision for a wide range of broad-leaved canopies markedly differing for their structure. To get a complete evaluation of the method accuracy, we also quantified its trueness using artificial canopy images with known canopy cover. Moreover, the effect of the segmentation method was analysed. The best results for precision (restrained limits of repeatability and reproducibility) were obtained for high LAI values (>5) with limits corresponding to a variation of 22% in the estimated LAI values. Poorer results were obtained for medium and low LAI values, with a variation of the estimated LAI values that exceeded the 40%. Regardless of the LAI range explored, satisfactory results were achieved for trees in row-structured plantations (limits almost equal to the 30% of the estimated LAI). Satisfactory results were achieved for trueness, regardless of the canopy structure. The paired t -test revealed that the effect of the segmentation method on LAI estimates was significant. Despite a non-negligible user effect, the accuracy metrics for DHP are consistent with those determined for other indirect methods for LAI estimates, confirming the overall reliability of DHP in broad-leaved woody canopies.

Quantifying the Accuracy of Digital Hemispherical Photography for Leaf Area Index Estimates on Broad-Leaved Tree Species

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Carlo Gilardelli

2018-03-01

Full Text Available Digital hemispherical photography (DHP has been widely used to estimate leaf area index (LAI in forestry. Despite the advancement in the processing of hemispherical images with dedicated tools, several steps are still manual and thus easily affected by user’s experience and sensibility. The purpose of this study was to quantify the impact of user’s subjectivity on DHP LAI estimates for broad-leaved woody canopies using the software Can-Eye. Following the ISO 5725 protocol, we quantified the repeatability and reproducibility of the method, thus defining its precision for a wide range of broad-leaved canopies markedly differing for their structure. To get a complete evaluation of the method accuracy, we also quantified its trueness using artificial canopy images with known canopy cover. Moreover, the effect of the segmentation method was analysed. The best results for precision (restrained limits of repeatability and reproducibility were obtained for high LAI values (>5 with limits corresponding to a variation of 22% in the estimated LAI values. Poorer results were obtained for medium and low LAI values, with a variation of the estimated LAI values that exceeded the 40%. Regardless of the LAI range explored, satisfactory results were achieved for trees in row-structured plantations (limits almost equal to the 30% of the estimated LAI. Satisfactory results were achieved for trueness, regardless of the canopy structure. The paired t-test revealed that the effect of the segmentation method on LAI estimates was significant. Despite a non-negligible user effect, the accuracy metrics for DHP are consistent with those determined for other indirect methods for LAI estimates, confirming the overall reliability of DHP in broad-leaved woody canopies.

[Conservative treatment of deciduous teeth--a review].

Science.gov (United States)

Magnusson, B

1976-06-01

In all countries with a lack of manpower in dentistry, there is an unfortunate tendency to leave the primary teeth without proper conservative treatment. In addition to toothaches and poor esthetics, a neglected care of the primary dentition may result in several other untoward effects. Decayed deciduous teeth may cause such a discomfort during tooth-brushing that the child is prevented from learning good oral hygiene habits. With bad primary molars the child cannot chew properly, and may have to choose soft and often cariogenic food. When the permanent teeth erupt among the decayed deciduous teeth, there will be a greater chance for them to have carious attacks as well. Premature loss of primary molars may lead to malocclusion. It must also be kept in mind that the treatment of badly decayed teeth, including necessary extractions, may be difficult. This may cause fear of dental treatment. On the basis of current Swedish philosophies of treatment the author surveys various conservative procedures for deciduous teeth-amalgam therapy, stainless steel crowns, composites and disking.

Net Ecosystem Fluxes of Hydrocarbons from a Ponderosa Pine Forest in Colorado

Science.gov (United States)

Rhew, R. C.; Turnipseed, A. A.; Ortega, J. V.; Smith, J. N.; Guenther, A. B.; Shen, S.; Martinez, L.; Koss, A.; Warneke, C.; De Gouw, J. A.; Deventer, M. J.

2015-12-01

Light (C2-C4) alkenes, light alkanes and isoprene (C5H8) are non-methane hydrocarbons that play important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. Natural terrestrial fluxes of the light hydrocarbons are poorly characterized, with global emission estimates based on limited field measurements. In 2014, net fluxes of these compounds were measured at the Manitou Experimental Forest Observatory, a semi-arid ponderosa pine forest in the Colorado Rocky Mountains and site of the prior BEACHON campaigns. Three field intensives were conducted between June 17 and August 10, 2014. Net ecosystem flux measurements utilized a relaxed eddy accumulation system coupled to an automated gas chromatograph. Summertime average emissions of ethene and propene were up to 90% larger than those observed from a temperate deciduous forest. Ethene and propene fluxes were also correlated to each other, similar to the deciduous forest study. Emissions of isoprene were small, as expected for a coniferous forest, and these fluxes were not correlated with either ethene or propene. Unexpected emissions of light alkanes were also observed, and these showed a distinct diurnal cycle. Understory flux measurements allowed for the partitioning of fluxes between the surface and the canopy. Full results from the three field intensives will be compared with environmental variables in order to parameterize the fluxes for use in modeling emissions.

Forecast for the dynamics of forests in Krasnoyarsk Krai

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V. A. Sokolov

2017-08-01

Full Text Available Dynamics of the forest ecosystems connects closely with the natural and anthropogenic changes (succession processes, forest fires, windfalls, forest insects, forest diseases, forest harvesting, reforestation, the infrastructure development associated and not associated with forestry and so forth. Authors do not consider the up-to-day problem of global warming on the Earth, as opinions of scientists are controversial. Retrospective analysis of forest dynamics of the Krasnoyarsk Territory for the last 50 years has allowed to assess the impact of these changes on condition of forests. The univocal conclusion of deterioration of forest quality has been drawn. Area of coniferous forests has decreased by 9 %, including the 25 % reduction of mature and overmature forest stands. To forecast forest dynamics, modelling of natural and anthropogenic processes in the forest ecosystems has been applied, taking into account that the existing system of measures for reforestation and tending care of forest actually does not affect dynamics of the forests. The provision about increase in forest harvesting volume to 37.6 million м3 of the Development Strategy of the Krasnoyarsk Forest Industrial Complex has been used for forecasting. It has been proved that such scale of forest harvesting will inevitably lead to the over-cutting of ecological and economic accessible allowable cut that will negatively affect the forest condition in 50 years. Our forecast of forest dynamics of the Krasnoyarsk Territory for the next 50 years has showed that negative changes will continue at the same pace under the current extensive form of forest management. What is more, the maximum decrease of forest area might be in pine forests (32.9 % with the significant increase of broadleaves forests – 22.7 %. To improve the situation in the Russian forest sector, a radical change in the system of forest management is needed.

The role of novel forest ecosystems in the conservation of wood?inhabiting fungi in boreal broadleaved forests

OpenAIRE

Juutilainen, Katja; M?nkk?nen, Mikko; Kotiranta, Heikki; Halme, Panu

2016-01-01

Abstract The increasing human impact on the earth's biosphere is inflicting changes at all spatial scales. As well as deterioration and fragmentation of natural biological systems, these changes also led to other, unprecedented effects and emergence of novel habitats. In boreal zone, intensive forest management has negatively impacted a multitude of deadwood?associated species. This is especially alarming given the important role wood?inhabiting fungi have in the natural decay processes. In t...

Evaluating the effect of alternative carbon allocation schemes in a land surface model (CLM4.5 on carbon fluxes, pools, and turnover in temperate forests

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F. Montané

2017-09-01

Full Text Available How carbon (C is allocated to different plant tissues (leaves, stem, and roots determines how long C remains in plant biomass and thus remains a central challenge for understanding the global C cycle. We used a diverse set of observations (AmeriFlux eddy covariance tower observations, biomass estimates from tree-ring data, and leaf area index (LAI measurements to compare C fluxes, pools, and LAI data with those predicted by a land surface model (LSM, the Community Land Model (CLM4.5. We ran CLM4.5 for nine temperate (including evergreen and deciduous forests in North America between 1980 and 2013 using four different C allocation schemes: i. dynamic C allocation scheme (named "D-CLM4.5" with one dynamic allometric parameter, which allocates C to the stem and leaves to vary in time as a function of annual net primary production (NPP; ii. an alternative dynamic C allocation scheme (named "D-Litton", where, similar to (i, C allocation is a dynamic function of annual NPP, but unlike (i includes two dynamic allometric parameters involving allocation to leaves, stem, and coarse roots; iii.–iv. a fixed C allocation scheme with two variants, one representative of observations in evergreen (named "F-Evergreen" and the other of observations in deciduous forests (named "F-Deciduous". D-CLM4.5 generally overestimated gross primary production (GPP and ecosystem respiration, and underestimated net ecosystem exchange (NEE. In D-CLM4.5, initial aboveground biomass in 1980 was largely overestimated (between 10 527 and 12 897 g C m−2 for deciduous forests, whereas aboveground biomass accumulation through time (between 1980 and 2011 was highly underestimated (between 1222 and 7557 g C m−2 for both evergreen and deciduous sites due to a lower stem turnover rate in the sites than the one used in the model. D-CLM4.5 overestimated LAI in both evergreen and deciduous sites because the leaf C–LAI relationship in the model did not match the

Variability in radial sap flux density patterns and sapwood area among seven co-occurring temperate broad-leaved tree species.

Science.gov (United States)

Gebauer, Tobias; Horna, Viviana; Leuschner, Christoph

2008-12-01

Forest transpiration estimates are frequently based on xylem sap flux measurements in the outer sections of the hydro-active stem sapwood. We used Granier's constant-heating technique with heating probes at various xylem depths to analyze radial patterns of sap flux density in the sapwood of seven broad-leaved tree species differing in wood density and xylem structure. Study aims were to (1) compare radial sap flux density profiles between diffuse- and ring-porous trees and (2) analyze the relationship between hydro-active sapwood area and stem diameter. In all investigated species except the diffuse-porous beech (Fagus sylvatica L.) and ring-porous ash (Fraxinus excelsior L.), sap flux density peaked at a depth of 1 to 4 cm beneath the cambium, revealing a hump-shaped curve with species-specific slopes. Beech and ash reached maximum sap flux densities immediately beneath the cambium in the youngest annual growth rings. Experiments with dyes showed that the hydro-active sapwood occupied 70 to 90% of the stem cross-sectional area in mature trees of diffuse-porous species, whereas it occupied only about 21% in ring-porous ash. Dendrochronological analyses indicated that vessels in the older sapwood may remain functional for 100 years or more in diffuse-porous species and for up to 27 years in ring-porous ash. We conclude that radial sap flux density patterns are largely dependent on tree species, which may introduce serious bias in sap-flux-derived forest transpiration estimates, if non-specific sap flux profiles are assumed.

Mapping Distinct Forest Types Improves Overall Forest Identification Based on Multi-Spectral Landsat Imagery for Myanmar’s Tanintharyi Region

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Grant Connette

2016-10-01

Full Text Available We investigated the use of multi-spectral Landsat OLI imagery for delineating mangrove, lowland evergreen, upland evergreen and mixed deciduous forest types in Myanmar’s Tanintharyi Region and estimated the extent of degraded forest for each unique forest type. We mapped a total of 16 natural and human land use classes using both a Random Forest algorithm and a multivariate Gaussian model while considering scenarios with all natural forest classes grouped into a single intact or degraded category. Overall, classification accuracy increased for the multivariate Gaussian model with the partitioning of intact and degraded forest into separate forest cover classes but slightly decreased based on the Random Forest classifier. Natural forest cover was estimated to be 80.7% of total area in Tanintharyi. The most prevalent forest types are upland evergreen forest (42.3% of area and lowland evergreen forest (21.6%. However, while just 27.1% of upland evergreen forest was classified as degraded (on the basis of canopy cover <80%, 66.0% of mangrove forest and 47.5% of the region’s biologically-rich lowland evergreen forest were classified as degraded. This information on the current status of Tanintharyi’s unique forest ecosystems and patterns of human land use is critical to effective conservation strategies and land-use planning.

Plot size recommendations for biomass estimation in a midwestern old-growth forest

Science.gov (United States)

Martin A. Spetich; George R Parker

1998-01-01

The authors examine the relationship between disturbance regime and plot size for woody biomass estimation in a midwestern old-growth deciduous forest from 1926 to 1992. Analysis was done on the core 19.6 ac of a 50.1 ac forest in which every tree 4 in. d.b.h. and greater has been tagged and mapped since 1926. Five windows of time are compared—1926, 1976, 1981, 1986...

Decidual activin: its role in the apoptotic process and its regulation by prolactin.

Science.gov (United States)

Tessier, Christian; Prigent-Tessier, Anne; Bao, Lei; Telleria, Carlos M; Ferguson-Gottschall, Susan; Gibori, Gil B; Gu, Yan; Bowen-Shauver, Jennifer M; Horseman, Nelson D; Gibori, Geula

2003-05-01

Successful pregnancy requires profound differentiation and reorganization of the uterine tissues including, as pregnancy progresses, extensive apoptosis of decidual tissue to accommodate the developing conceptus. We have previously shown a positive correlation between expression of activin A and apoptosis in the decidua and have also shown that expression of activin A occurs at the time when prolactin (PRL) receptors disappear from decidual cells. The goals of this study were to examine whether activin A plays a role in decidual apoptosis and whether expression of activin A in the decidua is regulated by PRL and placental lactogens. Studies were carried out using primary rat decidual cells, a decidual cell line (GG-AD), and PRL null mice. Treatment of decidual cells with activin A significantly increased DNA degradation, caspase 3 activity, and caspase 3 mRNA expression. However, this effect was observed only in the absence of endogenous activin production by these cells. Addition of follistatin to decidual cells that were producing activin A decreased both caspase 3 activity and mRNA expression. Similarly, addition of activin-blocking antibodies to cultures of GG-AD cells, which also produce activin A, caused a reduction in both DNA degradation and caspase 3 activity. PRL and placental lactogens caused an inhibition of activin A mRNA expression in primary decidual cells. Even more convincingly, decidua of PRL null mice expressed abundant activin A at a time when no expression of this hormone is detected in wild-type mice and treatment of PRL null mice with PRL caused a profound inhibition of activin A mRNA expression. In summary, our investigations into the role and regulation of decidual activin have revealed that activin A can induce cell death in the decidua and that its expression is under tight regulation by PRL and placental lactogens.

Silvicultural interpretation of natural vegetation dynamics in ageing Scots pine stands for their conversion into mixed broadleaved stands

NARCIS (Netherlands)

Kint, V.; Geudens, G.; Mohren, G.M.J.; Lust, N.

2006-01-01

In many West-European regions there is principal consensus on the conversion of homogeneous even-aged Scots pine plantations into mixed broadleaved stands. In recent years, interest is growing for conversion management in which managers try to maximise the use of natural processes by steering or

Comparison of vertical distribution of live and dead fine root biomass in six types of Cuban forests

Czech Academy of Sciences Publication Activity Database

Fiala, K.; Hernandéz, L.; Holub, Petr

2017-01-01

Roč. 29, č. 3 (2017), s. 275-281 ISSN 0128-1283 R&D Projects: GA MZe QJ1220007; GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:86652079 Keywords : Evergreen forests * mangroves * root dry mass * semi-deciduous forests * soil depth Subject RIV: GK - Forestry OBOR OECD: Forestry Impact factor: 0.466, year: 2016

Remote sensing of forest insect disturbances: Current state and future directions.

Science.gov (United States)

Senf, Cornelius; Seidl, Rupert; Hostert, Patrick

2017-08-01

Insect disturbance are important agents of change in forest ecosystems around the globe, yet their spatial and temporal distribution and dynamics are not well understood. Remote sensing has gained much attention in mapping and understanding insect outbreak dynamics. Consequently, we here review the current literature on the remote sensing of insect disturbances. We suggest to group studies into three insect types: bark beetles, broadleaved defoliators, and coniferous defoliators. By so doing, we systematically compare the sensors and methods used for mapping insect disturbances within and across insect types. Results suggest that there are substantial differences between methods used for mapping bark beetles and defoliators, and between methods used for mapping broadleaved and coniferous defoliators. Following from this, we highlight approaches that are particularly suited for each insect type. Finally, we conclude by highlighting future research directions for remote sensing of insect disturbances. In particular, we suggest to: 1) Separate insect disturbances from other agents; 2) Extend the spatial and temporal domain of analysis; 3) Make use of dense time series; 4) Operationalize near-real time monitoring of insect disturbances; 5) Identify insect disturbances in the context of coupled human-natural systems; and 6) Improve reference data for assessing insect disturbances. Since the remote sensing of insect disturbances has gained much interest beyond the remote sensing community recently, the future developments identified here will help integrating remote sensing products into operational forest management. Furthermore, an improved spatiotemporal quantification of insect disturbances will support an inclusion of these processes into regional to global ecosystem models.

Diversity and similarity of native forest fragments located in the northeast region of Minas Gerais

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Christianne Riquetti Corsini

2014-03-01

Full Text Available In this study 26 distributed fragments of native forest in four located hydrographical Basins in the northeast region of Minas Gerais had been showed, with the purpose of analyzing the floristic similarity exists between 26 forest fragments native inserted in four basins in the northeast of the state of Minas Gerais and the diversity and evenness of physiognomies studied and groups of fragments formed. Systematic sampling with units was used shows of 1000 m² each, where the sample area varied of 1 the 6 has, as the area I break up of it. We measured the circumference at 1.30m (CAP and the total height and collected botanical material of all individuals with CAP greater or equal to 15.7 cm. Six groups were formed according to the floristic similarity coefficient Sorensen, with four groups there was an association of more than a physiognomy, showing regions of transition within the area. The Shannon diversity index, ranged from 2.236 in deciduous forest to 4.523 in Semideciduous Forest. The maximum and minimum values of evenness index Pielou were 0.850 and 0.616 , respectively. The floristic group 2 (Semideciduous Forest and Cerrado sensu stricto had the highest average value of diversity (3.585 and evenness (0.750 , and group 1 (Deciduous Forest had the lowest values (H': 2.426 and J': 0.687 .

Assessment of post forest fire reclamation in Algarve, Portugal

Science.gov (United States)

Andrade, Rita; Panagopoulos, Thomas; Guerrero, Carlos; Martins, Fernando; Zdruli, Pandi; Ladisa, Gaetano

2014-05-01

Fire is a common phenomenon in Mediterranean landscapes and it plays a crucial role in its transformations, making the determination of its impact on the ecosystem essential for land management. During summer of 2012, a wildfire took place in Algarve, Portugal, on an area mainly covered by sclerophyllous vegetation (39.44%, 10080ha), broad-leaved forest (20.80%, 5300ha), agriculture land with significant areas of natural vegetation (17.40%, 4400ha) and transitional woodlands-shrubs (16.17%, 4100ha). The objective of the study was to determine fire severity in order to plan post-fire treatments and to aid vegetation recovery and land reclamation. Satellite imagery was used to estimate burn severity by detecting physical and ecological changes in the landscape caused by fire. Differenced Normalized Burn Ratio (DNBR) was used to measure burn severity with pre and post fire data of four Landsat images acquired in October 2011, February and August 2012 and April 2013. The initial and extended differenced normalized burn ratio (DiNBR and DeNBR) were calculated. The calculated burned area of 24291 ha was 552ha lower than the map data determined with field reports. The 19.5% of that area was burned with high severity, 45% with moderate severity and 28.3% with low severity. Comparing fire severity and regrowth with land use, it is shown in DiNBR that the most severely burned areas were predominantly sclerophyllous vegetation (37.6%) and broad-leaved forests (31.1%). From the DeNRB it was found that the reestablishment of vegetation was slower in mixed forests and higher in sclerophyllous vegetation and in land with significant areas of natural vegetation. Faster recovery was calculated for the land uses of sclerophyllous vegetation (46.7%) and significant regrowth in areas of natural vegetation and lands occupied by agriculture (25.4%). Next steps of the study are field validation and crossing with erosion risk maps before to take land reclamation decisions.

Modeling the Influence of Forest Structure on Microsite Habitat Use by Snowshoe Hares

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Angela K. Fuller

2013-01-01

Full Text Available Snowshoe hare (Lepus americanus is an important prey species for many Carnivora and has strong influences on community structure and function in northern forests. An understanding of within-stand (microsite forest structural characteristics that promote high use by hares is important to provide forest management guidelines. We measured forest structural characteristics at the microsite-scale in north-central Maine and used an information-theoretic modeling approach to infer which characteristics were most strongly associated with use by hares during winter. We measured overwinter hare pellet density to model relationships among microsite-scale vegetation structure and hare use. Overwinter pellet density was positively associated with live stem cover (3 × coniferous saplings + deciduous saplings and negatively associated with overstory canopy closure; the two variables explained 71% of the variation in microsite use by hares. The highest pellet densities were in grids with canopy closure 22,000 stems/ha. Silvicultural practices that create dense areas of conifer and deciduous saplings should receive high within-stand use by hares in winter. These conditions can be achieved by promoting the release of advanced regeneration and reducing overstory cover to encourage establishment of shade-intolerant species; clearcutting is one such silvicultural prescription to achieve these conditions.

Mercury dynamics and mass balance in a subtropical forest, southwestern China

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M. Ma

2016-04-01

Full Text Available The mid-subtropical forest area in southwest China was affected by anthropogenic mercury (Hg emissions over the past 3 decades. We quantified mercury dynamics on the forest field and measured fluxes and pools of Hg in litterfall, throughfall, stream water and forest soil in an evergreen broadleaved forest field in southwestern China. Total Hg (THg input by the throughfall and litterfall was assessed at 32.2 and 42.9 µg m−2 yr−1, respectively, which was remarkably higher than those observed from other forest fields in the background of North America and Europe. Hg fluxes across the soil–air interface (18.6 mg m−2 yr−1 and runoff and/or stream flow (7.2 µg m−2 yr−1 were regarded as the dominant ways for THg export from the forest field. The forest field hosts an enormous amount of atmospheric Hg, and its reserves is estimated to be 25 341 µg m2. The ratio of output to input Hg fluxes (0.34 is higher compared with other study sites. The higher output / input ratio may represent an important ecological risk for the downstream aquatic ecosystems, even if the forest field could be an effective sink of Hg.

Realizing Mitigation Efficiency of European Commercial Forests by Climate Smart Forestry.

Science.gov (United States)

Yousefpour, Rasoul; Augustynczik, Andrey Lessa Derci; Reyer, Christopher P O; Lasch-Born, Petra; Suckow, Felicitas; Hanewinkel, Marc

2018-01-10

European temperate and boreal forests sequester up to 12% of Europe's annual carbon emissions. Forest carbon density can be manipulated through management to maximize its climate mitigation potential, and fast-growing tree species may contribute the most to Climate Smart Forestry (CSF) compared to slow-growing hardwoods. This type of CSF takes into account not only forest resource potentials in sequestering carbon, but also the economic impact of regional forest products and discounts both variables over time. We used the process-based forest model 4 C to simulate European commercial forests' growth conditions and coupled it with an optimization algorithm to simulate the implementation of CSF for 18 European countries encompassing 68.3 million ha of forest (42.4% of total EU-28 forest area). We found a European CSF policy that could sequester 7.3-11.1 billion tons of carbon, projected to be worth 103 to 141 billion euros in the 21st century. An efficient CSF policy would allocate carbon sequestration to European countries with a lower wood price, lower labor costs, high harvest costs, or a mixture thereof to increase its economic efficiency. This policy prioritized the allocation of mitigation efforts to northern, eastern and central European countries and favored fast growing conifers Picea abies and Pinus sylvestris to broadleaves Fagus sylvatica and Quercus species.

Declines in populations of Salix caprea L.during forest regeneration after strong herbivore pressure

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Janusz B. Faliński

2014-01-01

Full Text Available Communities of broadleaved forest subject to strong pressure from large herbivores underwent degeneration. The relief of this pressure led to regeneration of the community, in which an important role was played by the sallow Salix caprea and other light-seeded pioneer species of tree (Populus tremula, Betula pendula and B. pubescens. Regeneration involving Salix caprea proceeded following the conservatorial protection of the degenerate stands in a reserve and later in Białowieża National Park. The emergence and development of the population of Salix caprea proceeded following the invasion of spruce, which coincided with the period of enhanced animal pressure on broadleaved forest. Salix caprea filled all the gaps in the tree stand arising as a result of the destruction of trees and undergrowth by herbivores (in the years 1892-1915. It also appeared en masse on old, at that time unforested, clearings and felled areas. In these places, Salix caprea created very abundant populations, with particular trees being in good condition, with a habit typical of forest trees and attaining considerable heights. The majority of trees were 50-60 years old at the time of death, although individuals reached 74 years of age. The process of extinction of the sallow population - observed over 19 years on permanent plots and fixed trees - proceeded very quickly, especially in the first decade of observation. It led to the almost complete disappearance of sallow for the forest communities of Białowieża National Park. The death of individual trees is preceded by impairment of their health and reduced annual increments in the 4-9 last years of life. The extinction of the population is associated with the loss of its primary phenological differentiation and with a change in the sex structure of the population from a prevalence of female trees to a near even distribution of the two sexes. The development of the populations of permanent constituents of the forest

[Odocoileus virginianus diet (Artiodactyla: Cervidae) in a temperate forest of Northern Oaxaca, Mexico].

Science.gov (United States)

González, Graciela; Briones-Salas, Miguel

2012-03-01

The Sierra Madre de Oaxaca region, located in the Northern state of Oaxaca, Mexico, is an area of forest ecosystems subject to high exploitation rates, although in some areas its temperate forests are conserved by indigenous community initiatives that live there. We analyzed the diet of white tailed-deer (Odocoileus virginianus) in the localities of Santa Catarina Lachatao and San Miguel Amatlán from June 1998 to August 1999. Sampling was done during both the wet and dry seasons, and included the observation of browsing traces (238 observations), microhistological analysis of deer feces (28 deer pellet-groups), and two stomach content analysis. The annual diet of white-tailed deer was composed of 42 species from 23 botanical families. The most represented families in the diet of this deer were Fagaceae, Asteraceae, Ericaceae and Fabaceae. There were significant differences in the alpha diversity of the diet during the wet and dry seasons (H'=2.957 and H'=1.832, respectively). The similarity percentage between seasons was 56%. Differences in plant species frequency were significantly higher during the wet season. Herbaceous plants made up the greatest percentage of all the species consumed. The preferred species throughout the year were Senecio sp. (shrub), Sedum dendroideum (herbaceous), Arctostaphylos pungens (shrub) and Satureja macrostema (shrub). Diet species richness was found to be lower than that observed in a tropical forest (Venezuela), tropical dry forest (Mexico) and temperate deciduous and mixed forest (Mexico), but similar to the diet species richness observed in a tropical dry forest (Costa Rica) and temperate coniferous and deciduous forests (USA).

Impacts of 21st century climate changes on flora and vegetation in Denmark

International Nuclear Information System (INIS)

Skov, Flemming; Nygaard, Bettina; Wind, Peter; Floejgaard, Camilla; Borchsenius, Finn; Normand, Signe; Balslev, Henrik; Svenning, Jens-Christian

2009-01-01

In this paper we examined the potential impacts of predicted climatic changes on the flora and vegetation in Denmark using data from a digital database on the natural vegetation of Europe. Climate scenarios A2 and B2 were used to find regions with present climatic conditions similar to Denmark's climate in the year 2100. The potential natural vegetation of Denmark today is predominantly deciduous forest that would cover more than 90% of the landscape. Swamps, bogs, and wet forest would be found under moist or wet conditions. Dwarf shrub heaths would be naturally occurring on poor soils along the coast together with dune systems and salt-marsh vegetation. When comparing the natural vegetation of Denmark to the vegetation of five future-climate analogue areas, the most obvious trend is a shift from deciduous to thermophilous broadleaved forest currently found in Southern and Eastern Europe. A total of 983 taxa were recorded for this study of which 539 were found in Denmark. The Soerensen index was used to measure the floristic similarity between Denmark and the five subregions. Deciduous forest, dwarf shrub heath, and coastal vegetation were treated in more detail, focusing on potential new immigrant species to Denmark. Finally, implications for management were discussed. The floristic similarity between Denmark and regions in Europe with a climate similar to what is expected for Denmark in year 2100 was found to vary between 48-78%, decreasing from North to South. Hence, it seems inevitable that climate changes of the magnitudes foreseen will alter the distribution of individual species and the composition of natural vegetation units. Changes, however, will not be immediate. Historic evidence shows a considerable lag in response to climatic change under natural conditions, but little is known about the effects of human land-use and pollution on this process. Facing such uncertainties we suggested that a dynamic strategy based on modeling, monitoring and adaptive

Impacts of 21st century climate changes on flora and vegetation in Denmark

Science.gov (United States)

Skov, Flemming; Nygaard, Bettina; Wind, Peter; Borchsenius, Finn; Normand, Signe; Balslev, Henrik; Fløjgaard, Camilla; Svenning, Jens-Christian

2009-11-01

In this paper we examined the potential impacts of predicted climatic changes on the flora and vegetation in Denmark using data from a digital database on the natural vegetation of Europe. Climate scenarios A2 and B2 were used to find regions with present climatic conditions similar to Denmark's climate in the year 2100. The potential natural vegetation of Denmark today is predominantly deciduous forest that would cover more than 90% of the landscape. Swamps, bogs, and wet forest would be found under moist or wet conditions. Dwarf shrub heaths would be naturally occurring on poor soils along the coast together with dune systems and salt-marsh vegetation. When comparing the natural vegetation of Denmark to the vegetation of five future-climate analogue areas, the most obvious trend is a shift from deciduous to thermophilous broadleaved forest currently found in Southern and Eastern Europe. A total of 983 taxa were recorded for this study of which 539 were found in Denmark. The Sørensen index was used to measure the floristic similarity between Denmark and the five subregions. Deciduous forest, dwarf shrub heath, and coastal vegetation were treated in more detail, focusing on potential new immigrant species to Denmark. Finally, implications for management were discussed. The floristic similarity between Denmark and regions in Europe with a climate similar to what is expected for Denmark in year 2100 was found to vary between 48-78%, decreasing from North to South. Hence, it seems inevitable that climate changes of the magnitudes foreseen will alter the distribution of individual species and the composition of natural vegetation units. Changes, however, will not be immediate. Historic evidence shows a considerable lag in response to climatic change under natural conditions, but little is known about the effects of human land-use and pollution on this process. Facing such uncertainties we suggested that a dynamic strategy based on modeling, monitoring and adaptive

Impacts of 21st century climate changes on flora and vegetation in Denmark

Energy Technology Data Exchange (ETDEWEB)

Skov, Flemming; Nygaard, Bettina; Wind, Peter; Floejgaard, Camilla [Department of Wildlife Ecology and Biodiversity, National Environmental Research Institute, Aarhus University, Grenaavej 14, DK-8410 Roende (Denmark); Borchsenius, Finn; Normand, Signe; Balslev, Henrik; Svenning, Jens-Christian, E-mail: fs@dmu.d [Department of Biological Sciences, Aarhus University, Ny Munkegade 114, DK-8000 Aarhus C (Denmark)

2009-11-01

In this paper we examined the potential impacts of predicted climatic changes on the flora and vegetation in Denmark using data from a digital database on the natural vegetation of Europe. Climate scenarios A2 and B2 were used to find regions with present climatic conditions similar to Denmark's climate in the year 2100. The potential natural vegetation of Denmark today is predominantly deciduous forest that would cover more than 90% of the landscape. Swamps, bogs, and wet forest would be found under moist or wet conditions. Dwarf shrub heaths would be naturally occurring on poor soils along the coast together with dune systems and salt-marsh vegetation. When comparing the natural vegetation of Denmark to the vegetation of five future-climate analogue areas, the most obvious trend is a shift from deciduous to thermophilous broadleaved forest currently found in Southern and Eastern Europe. A total of 983 taxa were recorded for this study of which 539 were found in Denmark. The Soerensen index was used to measure the floristic similarity between Denmark and the five subregions. Deciduous forest, dwarf shrub heath, and coastal vegetation were treated in more detail, focusing on potential new immigrant species to Denmark. Finally, implications for management were discussed. The floristic similarity between Denmark and regions in Europe with a climate similar to what is expected for Denmark in year 2100 was found to vary between 48-78%, decreasing from North to South. Hence, it seems inevitable that climate changes of the magnitudes foreseen will alter the distribution of individual species and the composition of natural vegetation units. Changes, however, will not be immediate. Historic evidence shows a considerable lag in response to climatic change under natural conditions, but little is known about the effects of human land-use and pollution on this process. Facing such uncertainties we suggested that a dynamic strategy based on modeling, monitoring and

Background concentrations and fluxes of atmospheric ammonia over a deciduous forest

DEFF Research Database (Denmark)

Hansen, K.; Pryor, S. C.; Boegh, E.

2015-01-01

. In this study, we present two months of half-hourly NH3 fluxes and concentrations measured using a Relaxed Eddy Accumulation system during late summer and fall 2013 above a remote forest site in the central Midwest in USA. Supplementary nitric acid (HNO3) flux and size-resolved aerosol-N measurements are used.......11 μg NH3-N m−2 s−1. The wetness of the forest surfaces (assessed using a proxy of time since precipitation) was found to be crucial in controlling both deposition and emission of atmospheric NH3. Size resolved aerosol concentrations (of NH4+, NO3−, Cl− and SO42−) indicated that the aerosol and gas...

The use of deciduous molars in EPR dose reconstruction

International Nuclear Information System (INIS)

El-faramawy, N.A.; Wieser, A.

2005-01-01

The use of deciduous teeth in EPR dose reconstruction has the unique potential to measure individual doses that were accumulated in the early childhood in the age up to 12 years. It was found previously that due to the small size of deciduous incisors, the available amount of enamel is not sufficient for EPR measurements. Therefore, dose assessment with deciduous incisors can only be done by measurement of whole teeth, including enamel and dentine. The measurement of whole teeth instead of enamel alone is possibly less reliable for dose reconstruction because the stability of CO 2 - radicals (that are an indicator for the absorbed dose) in biologically active dentine is not known. In the present study naturally loosed deciduous molars were investigated. The feasibility of separating enamel from small size molars was analysed. EPR spectrum parameters of whole molars and separated enamel only were evaluated before and after laboratory irradiation. The EPR signal amplitudes of the CO 2 - and native signals were determined by spectrum deconvolution, in dependence on radiation dose in the range 0.1 - 10 Gy. The fading at room temperature of native and CO 2 - EPR signals was analysed. The detection threshold for absorbed dose in enamel was determined.

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: Determination of specific emission rates for thirty-one tree species

International Nuclear Information System (INIS)

Aydin, Yagmur Meltem; Yaman, Baris; Koca, Husnu; Dasdemir, Okan; Kara, Melik; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Tolunay, Doganay; Odabasi, Mustafa; Elbir, Tolga

2014-01-01

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO 2 ) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m 2 s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/g h was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/g h. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta-pinene and

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: Determination of specific emission rates for thirty-one tree species

Energy Technology Data Exchange (ETDEWEB)

Aydin, Yagmur Meltem; Yaman, Baris; Koca, Husnu; Dasdemir, Okan; Kara, Melik; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, Buca, Izmir (Turkey); Tolunay, Doganay [Department of Soil Science and Ecology, Faculty of Forestry, Istanbul University, Bahcekoy, Istanbul (Turkey); Odabasi, Mustafa [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, Buca, Izmir (Turkey); Elbir, Tolga, E-mail: tolga.elbir@deu.edu.tr [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, Buca, Izmir (Turkey)

2014-08-15

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO{sub 2}) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m{sup 2} s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/g h was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/g h. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta

Airborne S-Band SAR for Forest Biophysical Retrieval in Temperate Mixed Forests of the UK

Directory of Open Access Journals (Sweden)

Ramesh K. Ningthoujam

2016-07-01

Full Text Available Radar backscatter from forest canopies is related to forest cover, canopy structure and aboveground biomass (AGB. The S-band frequency (3.1–3.3 GHz lies between the longer L-band (1–2 GHz and the shorter C-band (5–6 GHz and has been insufficiently studied for forest applications due to limited data availability. In anticipation of the British built NovaSAR-S satellite mission, this study evaluates the benefits of polarimetric S-band SAR for forest biophysical properties. To understand the scattering mechanisms in forest canopies at S-band the Michigan Microwave Canopy Scattering (MIMICS-I radiative transfer model was used. S-band backscatter was found to have high sensitivity to the forest canopy characteristics across all polarisations and incidence angles. This sensitivity originates from ground/trunk interaction as the dominant scattering mechanism related to broadleaved species for co-polarised mode and specific incidence angles. The study was carried out in the temperate mixed forest at Savernake Forest and Wytham Woods in southern England, where airborne S-band SAR imagery and field data are available from the recent AirSAR campaign. Field data from the test sites revealed wide ranges of forest parameters, including average canopy height (6–23 m, diameter at breast-height (7–42 cm, basal area (0.2–56 m2/ha, stem density (20–350 trees/ha and woody biomass density (31–520 t/ha. S-band backscatter-biomass relationships suggest increasing backscatter sensitivity to forest AGB with least error between 90.63 and 99.39 t/ha and coefficient of determination (r2 between 0.42 and 0.47 for the co-polarised channel at 0.25 ha resolution. The conclusion is that S-band SAR data such as from NovaSAR-S is suitable for monitoring forest aboveground biomass less than 100 t/ha at 25 m resolution in low to medium incidence angle range.

Evaluating the Contribution of Climate Forcing and Forest Dynamics to Accelerating Carbon Sequestration by Forest Ecosystems in the Northeastern U.S.: Final Report

Energy Technology Data Exchange (ETDEWEB)

Munger, J. William [Harvard University, SEAS; Foster, David R. [Harvard University, Harvard Forest; Richardson, Andrew D. [Harvard University, OEB

2014-10-01

This report summarizes work to improve quantitative understanding of the terrestrial ecosystem processes that control carbon sequestration in unmanaged forests It builds upon the comprehensive long-term observations of CO2 fluxes, climate and forest structure and function at the Harvard Forest in Petersham, MA. This record includes the longest CO2 flux time series in the world. The site is a keystone for the AmeriFlux network. Project Description The project synthesizes observations made at the Harvard Forest HFEMS and Hemlock towers, which represent the dominant mixed deciduous and coniferous forest types in the northeastern United States. The 20+ year record of carbon uptake at Harvard Forest and the associated comprehensive meteorological and biometric data, comprise one of the best data sets to challenge ecosystem models on time scales spanning hourly, daily, monthly, interannual and multi-decadal intervals, as needed to understand ecosystem change and climate feedbacks.

Abundance and population structure of eastern worm snakes in forest stands with various levels of overstory tree retention

Science.gov (United States)

Zachary I. Felix; Yong Wang; Callie Jo Schweitzer

2010-01-01

In-depth analyses of a species’ response to canopy retention treatments can provide insight into reasons for observed changes in abundance. The eastern worm snake (Carphophis amoenus amoenus Say) is common in many eastern deciduous forests, yet little is known about the ecology of the species in managed forests. We examined the relationship between...

Effects of disturbance and climate change on ecosystem performance in the Yukon River Basin boreal forest

Science.gov (United States)

Wylie, Bruce K.; Rigge, Matthew B.; Brisco, Brian; Mrnaghan, Kevin; Rover, Jennifer R.; Long, Jordan

2014-01-01

A warming climate influences boreal forest productivity, dynamics, and disturbance regimes. We used ecosystem models and 250 m satellite Normalized Difference Vegetation Index (NDVI) data averaged over the growing season (GSN) to model current, and estimate future, ecosystem performance. We modeled Expected Ecosystem Performance (EEP), or anticipated productivity, in undisturbed stands over the 2000–2008 period from a variety of abiotic data sources, using a rule-based piecewise regression tree. The EEP model was applied to a future climate ensemble A1B projection to quantify expected changes to mature boreal forest performance. Ecosystem Performance Anomalies (EPA), were identified as the residuals of the EEP and GSN relationship and represent performance departures from expected performance conditions. These performance data were used to monitor successional events following fire. Results suggested that maximum EPA occurs 30–40 years following fire, and deciduous stands generally have higher EPA than coniferous stands. Mean undisturbed EEP is projected to increase 5.6% by 2040 and 8.7% by 2070, suggesting an increased deciduous component in boreal forests. Our results contribute to the understanding of boreal forest successional dynamics and its response to climate change. This information enables informed decisions to prepare for, and adapt to, climate change in the Yukon River Basin forest.

Involvement of atypical transcription factor E2F8 in the polyploidization during mouse and human decidualization.

Science.gov (United States)

Qi, Qian-Rong; Zhao, Xu-Yu; Zuo, Ru-Juan; Wang, Tong-Song; Gu, Xiao-Wei; Liu, Ji-Long; Yang, Zeng-Ming

2015-01-01

Polyploid decidual cells are specifically differentiated cells during mouse uterine decidualization. However, little is known about the regulatory mechanism and physiological significance of polyploidization in pregnancy. Here we report a novel role of E2F8 in the polyploidization of decidual cells in mice. E2F8 is highly expressed in decidual cells and regulated by progesterone through HB-EGF/EGFR/ERK/STAT3 signaling pathway. E2F8 transcriptionally suppresses CDK1, thus triggering the polyploidization of decidual cells. E2F8-mediated polyploidization is a response to stresses which are accompanied by decidualization. Interestingly, polyploidization is not detected during human decidualization with the down-regulation of E2F8, indicating differential expression of E2F8 may lead to the difference of decidual cell polyploidization between mice and humans.

[Effects of forest regeneration patterns on the quantity and chemical structure of soil solution dissolved organic matter in a subtropical forest.

Science.gov (United States)

Yuan, Xiao Chun; Lin, Wei Sheng; Pu, Xiao Ting; Yang, Zhi Rong; Zheng, Wei; Chen, Yue Min; Yang, Yu Sheng

2016-06-01

Using the negative pressure sampling method, the concentrations and spectral characte-ristics of dissolved organic matter (DOM) of soil solution were studied at 0-15, 15-30, 30-60 cm layers in Castanopsis carlesii forest (BF), human-assisted naturally regenerated C. carlesii forest (RF), C. carlesii plantation (CP) in evergreen broad-leaved forests in Sanming City, Fujian Pro-vince. The results showed that the overall trend of dissolved organic carbon (DOC) concentrations in soil solution was RF>CP>BF, and the concentration of dissolved organic nitrogen (DON) was highest in C. carlesii plantation. The concentrations of DOC and DON in surface soil (0-15 cm) were all significantly higher than in the subsurface (30-60 cm). The aromatic index (AI) was in the order of RF>CP>BF, and as a whole, the highest AI was observed in the surface soil. Higher fluorescence intensity and a short wave absorption peak (320 nm) were observed in C. carlesii plantation, suggesting the surface soil of C. carlesii plantation was rich in decomposed substance content, while the degree of humification was lower. A medium wave absorption peak (380 nm) was observed in human-assisted naturally regenerated C. carlesii forest, indicating the degree of humification was higher which would contribute to the storage of soil fertility. In addition, DOM characte-ristics in 30-60 cm soil solution were almost unaffected by forest regeneration patterns.

Simulating carbon dioxide exchange rates of deciduous tree species: evidence for a general pattern in biochemical changes and water stress response.

Science.gov (United States)

Reynolds, Robert F; Bauerle, William L; Wang, Ying

2009-09-01

Deciduous trees have a seasonal carbon dioxide exchange pattern that is attributed to changes in leaf biochemical properties. However, it is not known if the pattern in leaf biochemical properties - maximum Rubisco carboxylation (V(cmax)) and electron transport (J(max)) - differ between species. This study explored whether a general pattern of changes in V(cmax), J(max), and a standardized soil moisture response accounted for carbon dioxide exchange of deciduous trees throughout the growing season. The model MAESTRA was used to examine V(cmax) and J(max) of leaves of five deciduous trees, Acer rubrum 'Summer Red', Betula nigra, Quercus nuttallii, Quercus phellos and Paulownia elongata, and their response to soil moisture. MAESTRA was parameterized using data from in situ measurements on organs. Linking the changes in biochemical properties of leaves to the whole tree, MAESTRA integrated the general pattern in V(cmax) and J(max) from gas exchange parameters of leaves with a standardized soil moisture response to describe carbon dioxide exchange throughout the growing season. The model estimates were tested against measurements made on the five species under both irrigated and water-stressed conditions. Measurements and modelling demonstrate that the seasonal pattern of biochemical activity in leaves and soil moisture response can be parameterized with straightforward general relationships. Over the course of the season, differences in carbon exchange between measured and modelled values were within 6-12 % under well-watered conditions and 2-25 % under water stress conditions. Hence, a generalized seasonal pattern in the leaf-level physiological change of V(cmax) and J(max), and a standardized response to soil moisture was sufficient to parameterize carbon dioxide exchange for large-scale evaluations. Simplification in parameterization of the seasonal pattern of leaf biochemical activity and soil moisture response of deciduous forest species is demonstrated. This

Effects of Fireplace Use on Forest Vegetation and Amount of Woody Debris in Suburban Forests in Northwestern Switzerland

Science.gov (United States)

Hegetschweiler, K. Tessa; van Loon, Nicole; Ryser, Annette; Rusterholz, Hans-Peter; Baur, Bruno

2009-02-01

Urban forests are popular recreation areas in Europe. Several of these temperate broad-leaved forests also have a high conservation value due to sustainable management over many centuries. Recreational activities, particularly the use of fireplaces, can cause extensive damage to soil, ground vegetation, shrubs, and trees. Firewood collection depletes woody debris, leading to a loss of habitat for specialized organisms. We examined the effects of fireplace use on forest vegetation and the amount of woody debris by comparing disturbed and control plots in suburban forests in northwestern Switzerland. At frequently used fireplaces, we found reduced species densities in the ground vegetation and shrub layer and changes in plant species composition due to human trampling within an area of 150-200 m2. Picnicking and grilling also reduced the height and changed the age structure of shrubs and young trees. The amount of woody debris was lower in disturbed plots than in control plots. Pieces of wood with a diameter of 0.6-7.6 cm were preferentially collected by fireplace users. The reduction in woody debris volume extended up to a distance of 16 m from the fire ring, covering an area of 800 m2 at each picnic site. In order to preserve the ecological integrity of urban forests and to maintain their attractiveness as important recreation areas, we suggest depositing logging residues to be used as firewood and to restrict visitor movements near picnic sites.

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

Directory of Open Access Journals (Sweden)

Catherine K. Denny

2017-04-01

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

Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America

Science.gov (United States)

Creed, Irena F; Spargo, Adam T; Jones, Julia A; Buttle, Jim M; Adams, Mary B; Beall, Fred D; Booth, Eric G; Campbell, John L; Clow, Dave; Elder, Kelly; Green, Mark B; Grimm, Nancy B; Miniat, Chelcy; Ramlal, Patricia; Saha, Amartya; Sebestyen, Stephen; Spittlehouse, Dave; Sterling, Shannon; Williams, Mark W; Winkler, Rita; Yao, Huaxia

2014-01-01

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment's change in actual ET divided by P [AET/P; evaporative index (EI)] coincident with a shift from a cool to a warm period – a positive d indicates an upward shift in EI and smaller than expected water yields, and a negative d indicates a downward shift in EI and larger than expected water yields. Elasticity was defined as the ratio of interannual variation in potential ET divided by P (PET/P; dryness index) to interannual variation in the EI – high elasticity indicates low d despite large range in drying index (i.e., resilient water yields), low elasticity indicates high d despite small range in drying index (i.e., nonresilient water yields). Although the data needed to fully evaluate ecosystems based on these metrics are limited, we were able to identify some characteristics of response among forest types. Alpine sites showed the greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer forests included catchments with lowest elasticity and stable to larger water yields. Deciduous forests included catchments with intermediate elasticity and stable to smaller water yields. Mixed coniferous/deciduous forests included catchments with highest elasticity and stable water yields. Forest type appeared to influence the resilience of catchment water yields to climate warming, with conifer and deciduous catchments more susceptible to