نتایج جستجو برای: forest ecosystems

تعداد نتایج: 144986  

2007
Jose A. Carrera Estanislao de Simon Manuel Fisac

Dr. Engineers, ICONA (Instituto National para la Conservacion de la Naturaleza), Madrid, Spain. Abstract: Management of the fragile and greatly modified ecosystems in the Spanish Mediterranean climate is complex. Rainfall occurs in a few intensive storms on rough topography. Climax vegetation is sparse forest dominated by evergreen xerophilic species. The emphases of the National Institute for ...

Journal: :گیاه پزشکی 0

ground beetles (carabidae) with more than 40,000 described species worldwide are one of the main generalist predator groups and have an important role in reducing pest population and enhancing biodiversity of agricultural and wild ecosystems. specimens from different agricultural and forest ecosystems in azadshahr region, golestan province, northern iran, using pitfall traps and light traps, be...

1999
W. J. OTROSINA

s SUMMARY Root disease fungi, particularly root rotting Basidiomycetes, are key drivers of forest ecosystems. These fungi have co-evolved with their hosts in various forest ecosystems and are in various states of equilibrium with them. Management activities and various land uses have taken place in recent times that have dramatically altered edaphic and environmental conditions under which fore...

2005

The dC values of atmospheric carbon dioxide (CO2) can be used to partition global patterns of CO2 source/sink relationships among terrestrial and oceanic ecosystems using the inversion technique. This approach is very sensitive to estimates of photosynthetic C discrimination by terrestrial vegetation (DA), and depends on d C values of respired CO2 fluxes (d CR). Here we show that by combining t...

2005

The dC values of atmospheric carbon dioxide (CO2) can be used to partition global patterns of CO2 source/sink relationships among terrestrial and oceanic ecosystems using the inversion technique. This approach is very sensitive to estimates of photosynthetic C discrimination by terrestrial vegetation (DA), and depends on d C values of respired CO2 fluxes (d CR). Here we show that by combining t...

2016

Most native species of plants and animals inhabiting forest ecosystems evolved with natural adaptations to the patterns and processes of fire disturbance and recovery.[1] One of the effects of fire disturbances is the creation of dead trees, both standing "snags" and downed logs. Fire-killed snags and logs serve vital roles in the structure and function of healthy forest ecosystems in general, ...

2006
P. Ambus S. Zechmeister-Boltenstern K. Butterbach-Bahl

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 betwe...

2008
David B. Lindenmayer Joern Fischer Adam Felton Mason Crane Damian Michael Christopher Macgregor Rebecca Montague-Drake Adrian Manning Richard J. Hobbs

Introduction: Novel ecosystems occur when new combinations of species appear within a particular biome due to human activity, environmental change, or impacts of introduced species. Background: Managing the trajectory of ecosystems toward desired outcomes requires an understanding of the means by which they developed. To facilitate this understanding, we present evidence for the development of ...

2009
Suqing Liu Xiumei Gao Qunying Zen Yuanman Zhou Yuequn Huang Weidong Han Linfeng Li Jiping Li Yingshan Pu

Characterized by their openness, complexity and large scale, forest ecosystems interweave themselves with social system, economic system and other natural ecosystems, thus complicating both their researches and management decision-making. According to the theories of sustainable development, hierarchy-competence levels, cybernetics and feedback, 25 factors have been chosen from human society, e...

2006
Torbern Tagesson

Boreal and temperate ecosystems of the northern hemisphere are important for the future development of global climate. In this study, the carbon cycle has been studied in a pine forest, a meadow, a spruce forest and two deciduous forests in the Simpevarp investigation area in southern Sweden (57°5’N, 34°55’E). Ground respiration and ground Gross Primary Production (GPP) has been measured three ...

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