Ground Vegetation Biomass, Production, and Efficiency of Energy Utilization in Some Northern Wisconsin Forest Ecosystems

Ecology ◽  
1976 ◽  
Vol 57 (4) ◽  
pp. 694-706 ◽  
Author(s):  
J. Zavitkovski
Keyword(s):  
Biomass Production ◽  
Forest Ecosystems ◽  
Energy Utilization ◽  
Ground Vegetation ◽  
Vegetation Biomass

scholarly journals Problématique du bilan de carbone dans les écosystèmes forestiers: exemple d'une jeune hêtraie de plaine | Problematics of the Carbon Net-Balance Within the Forest Ecosystems: a Juvenile Beech Forest in the Lowlands

2000 ◽  
Vol 151 (9) ◽  
pp. 317-324
Author(s):  
André Granier ◽  
Claire Damesin ◽  
Daniel Epron ◽  
Valérie Le Dantec
Keyword(s):  
Biomass Production ◽  
Forest Ecosystems ◽  
Photosynthetic Activity ◽  
Carbon Fluxes ◽  
Beech Forest ◽  
High Variability ◽  
Daily Cycles

The results of an investigation carried through within the ‹Euroflux›-programme in eastern France assessing the carbon fluxes above the canopy of the forest are presented. The photosynthetic activity within the annual and daily cycles are discussed. The high variability of the carbon netbalance and the variation of the total respiration make further research into the understanding of the correlation between the carbon net-balance and the biomass production necessary.

scholarly journals Effects of reindeer grazing and recovery after cessation of grazing on the ground-dwelling spider assemblage in Finnish Lapland

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7330
Author(s):  
Teemu Saikkonen ◽  
Varpu Vahtera ◽  
Seppo Koponen ◽  
Otso Suominen
Keyword(s):  
Species Richness ◽  
Rangifer Tarandus ◽  
Forest Ecosystems ◽  
Grazing Pressure ◽  
Ground Vegetation ◽  
Total Abundance ◽  
Finnish Lapland ◽  
Species Specific ◽  
The Impact

The effect of reindeer Rangifer tarandus L. grazing on the ground-dwelling spider assemblage in Northern Finland was studied. Changes in species richness, abundance and evenness of spider assemblages were analyzed in relation to changes in vegetation and environmental factors in long term grazed and ungrazed sites as well as sites that had recently switched from grazed to ungrazed and vice versa. Grazing was found to have a significant impact on height and biomass of lichens and other ground vegetation. However, it seemed not to have an impact on the total abundance of spiders. This is likely caused by opposing family and species level responses of spiders to the grazing regime. Lycosid numbers were highest in grazed and linyphiid numbers in ungrazed areas. Lycosidae species richness was highest in ungrazed areas whereas Linyphiidae richness showed no response to grazing. Four Linyphiidae, one Thomisidae and one Lycosidae species showed strong preference for specific treatments. Sites that had recovered from grazing for nine years and the sites that were grazed for the last nine years but were previously ungrazed resembled the long term grazed sites. The results emphasize the importance of reindeer as a modifier of boreal forest ecosystems but the impact of reindeer grazing on spiders seems to be family and species specific. The sites with reversed grazing treatment demonstrate that recovery from strong grazing pressure at these high latitudes is a slow process whereas reindeer can rapidly change the conditions in previously ungrazed sites similar to long term heavily grazed conditions.

scholarly journals Global vegetation biomass production efficiency constrained by models and observations

2019 ◽  
Vol 26 (3) ◽  
pp. 1474-1484 ◽  
Author(s):  
Yue He ◽  
Shushi Peng ◽  
Yongwen Liu ◽  
Xiangyi Li ◽  
Kai Wang ◽  
...  
Keyword(s):  
Biomass Production ◽  
Production Efficiency ◽  
Vegetation Biomass ◽  
Global Vegetation

Nitrogen deposition and effects on European forests

2000 ◽  
Vol 8 (2) ◽  
pp. 65-93 ◽  
Author(s):  
J W Erisman ◽  
W de Vries
Keyword(s):  
Species Diversity ◽  
Nitrogen Deposition ◽  
Forest Ecosystems ◽  
N Deposition ◽  
Ground Vegetation ◽  
N Saturation ◽  
Input Output ◽  
Soil Response ◽  
Field Evidence ◽  
The Impact

Hypotheses about the impacts of elevated atmospheric deposition of nitrogen on the forest ecosystem include an increased sensitivity to natural stress, impacts on roots, reduced species diversity of the ground vegetation, reduced growth, and unbalanced nutritional status due to eutrophication and acidification. The impact of N deposition has gained in ecological importance during recent decades, in part due to the steady decline in S emissions. Results of throughfall and deposition measurements at 163 plots in Europe show that total deposition of S and N compounds ranged from 100 to 3000 mol ha–1 yr–1 in approximately 90% of the plots, but values up to 4000–8000 mol ha–1 yr–1 were also observed. Approximately 50% of the plots received N inputs, dominated by NH4, above 1000 mol ha–1 yr–1, which is a deposition level at which species diversity of the ground vegetation may be at risk. Results of input–output budgets for plots concentrated in Northern and Western Europe indicate that nitrate leaching starts to occur at throughfall inputs above 10 kg ha–1 yr–1, specifically in soils with C/N ratios in the humus layer below 25. Examples are given of field evidence for impacts of elevated N deposition, including elevated N contents in foliage and soil, Al release in soil response to increased nitrate concentrations, reduced shoot/root ratios, and a reduction in species diversity. Although knowledge about the response of forest ecosystems to N inputs has increased over the last decade, there is still a lack of information on the dynamics of N accumulation and related critical N loads in a range of environmental conditions. Furthermore, a European-wide perspective of N saturation in forest ecosystems is still lacking.Key words: nitrogen, deposition, input–output budgets, nitrogen status, forests, effects.

The history and possible causes of forest decline in central Europe, with particular attention to the German situation

1995 ◽  
Vol 3 (3-4) ◽  
pp. 262-276 ◽  
Author(s):  
Bernhard Ulrich
Keyword(s):  
Soil Acidification ◽  
Air Pollutants ◽  
Large Scale ◽  
Forest Ecosystems ◽  
Fine Root ◽  
Human Impacts ◽  
Tree Regeneration ◽  
Anthropogenic Sources ◽  
Tree Level ◽  
Ground Vegetation

The elasticity (nutrient storage, litter decomposition, bioturbation of soil) and diversity of central European forest ecosystems has been reduced by centuries of overutilization. Since the middle of the nineteenth century, their development has been influenced by silvicultural measures, as well as by the deposition of acids and nutrients, especially nitrogen from anthropogenic sources, i.e., by a mixture of stabilizing and destabilizing external influences. During recent decades, most forest soils have been acidified by acid deposition resulting in low levels of nutrient cations and negative alkalinity in the soil solution. Widespread acute acidification of soil in the rooting zone is indicated by extremely high manganese (Mn) contents in leaves (fingerprint). Soil acidification has caused drastic losses of fine roots in subsoil, indicated by denuded structural root systems where adventitious fine root complexes exist only sporadically. Research at the organ (leaf, fine root, mycorrhiza) and cellular levels has provided much information on the effects of air pollutants and soil acidification on leaves and roots. There are considerable uncertainties, however, as to how changes in the status of leaves or roots are processed within the tree and ecosystem from one level of hierarchy to the next on an increasing spatial and time scale, and how these lead to decline symptoms like crown thinning, stand opening (as a consequence of dieback or perturbations), and changes in species composition (soil biota, ground vegetation, tree regeneration). At the tree level, nutrient imbalances (due to cation losses from soil, changes in the acid/base status of the soil, proton buffering in leaves, and N deposition), as well as disturbances in the transport system of assimilates and water, are suspected of causing the decline symptoms. Information on the filtering mechanisms at various hierarchical levels, especially in the case of a break in the hierarchy, is missing. The null hypothesis (no effects of air pollutants on forest ecosystems) can be considered to be falsified. Forest ecosystems are in transition. The current state of knowledge is not sufficient to define precisely the final state that will be reached, given continuously changing environmental conditions and human impacts. The hypothesis, however, of large-scale forest dieback in the near future is not backed by data and can be discarded.Key words: forest ecosystem, process hierarchy, air pollution, deposition, acidity, nitrogen.

scholarly journals Climate change within Serbian forests: Current state and future perspectives

Topola ◽  
2021 ◽  
pp. 39-56
Author(s):  
Dejan Stojanović ◽  
Saša Orlović ◽  
Milica Zlatković ◽  
Saša Kostić ◽  
Verica Vasić ◽  
...  
Keyword(s):  
Climate Change ◽  
Tree Species ◽  
Forest Ecosystems ◽  
Insect Pests ◽  
Heat Waves ◽  
Ground Vegetation ◽  
Human Society ◽  
Climate Conditions ◽  
Pests And Diseases ◽  
Precipitation Decrease

Extreme weather conditions, namely droughts, heat waves, heavy rains, floods, and landslides are becoming more frequent globally and in Serbia as a result of climate change. Generally, various parts of human society are affected by changing climate conditions. Forest ecosystems are one of the most sensitive systems to weather and climate. In that sense, small changes may lead to large disturbances including forest decline, outbreaks of insect pests and diseases and eventually mortality. In Serbia, the average temperature in forest ecosystems of the most important and abundant forest tree species has risen for more than 1°C in the last thirty years (1990-2019) in comparison to the previous period (1961-1990). During the last thirty years, the northern and western parts of Serbia experienced an increase in precipitation as opposed to the southern and eastern parts of the country. If one takes a closer look at the climate within a particular forest stands, it would seem that the effect of precipitation decrease is stronger in less humid parts of a tree species range. In this paper, we discuss various aspects of climate change impacts on forests and forestry, including forest ecology, genetics, physiology, pests and diseases, ground vegetation, monitoring, reporting and verification system, climate change litigation and perspectives of forests in the 21st century in Serbia.

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