نتایج جستجو برای: environmental ecosystems

تعداد نتایج: 405619  

Journal: :journal of rangeland science 2015
javad mirzaei arash karami

plant diversityis essential to maintain the health of planet's ecosystems. conservation of biodiversity is necessary for the ecological stability and productivity in natural ecosystems. the aim of this research was to study the biodiversity and richness of plant species (including trees, shrubs and grasses) related to the environmental factors (soil and physiography) in the forests of zagros, w...

Journal: :Ecology letters 2008
Shawn J Leroux Michel Loreau

Ecosystems are differentially open to subsidies of energy, material and organisms. This fundamental ecosystem attribute has long been recognized but the influence of this property on community regulation has not been investigated. We propose that this environmental attribute may explain variation in the strength of trophic cascades among ecosystems. Simply because of gravity, we should predict ...

2014
Li Xu Feng Zhang Kun Zhang Erkang Wang Jin Wang

The species in ecosystems are mutually interacting and self sustainable stable for a certain period. Stability and dynamics are crucial for understanding the structure and the function of ecosystems. We developed a potential and flux landscape theory of ecosystems to address these issues. We show that the driving force of the ecological dynamics can be decomposed to the gradient of the potentia...

2007
R. A. Houghton

PB 103 The six chapters (Chapters 10-15) in Part III consider the current and future carbon balance of terrestrial and aquatic ecosystems in North America. Although the amount of carbon exchanged between these ecosystems and the atmosphere each year through photosynthesis and plant and microbial respiration is large, the net balance for all of the ecosystems combined is currently a net sink of ...

2005
Robert H. Hilderbrand Adam C. Watts April M. Randle

Humanity’s ever-increasing ability to effect environmental change on a number of spatial and temporal scales requires tough decisions about how we view, value, and manage ecosystems. For example, advances in agriculture that support vastly more people per unit area than hunting and gathering are clearly a positive outcome for society. However, many beneficial land-use practices, including agric...

Journal: :Journal of environmental management 2015
Clive L Spash Iulie Aslaksen

In this paper we explore the discourses of ecology, environmental economics, new environmental pragmatism and social ecological economics as they relate to the value of ecosystems and biodiversity. Conceptualizing biodiversity and ecosystems as goods and services that can be represented by monetary values in policy processes is an economic discourse being increasingly championed by ecologists a...

2017
Pavel Kratina Jana S Petermann Nicholas A C Marino Andrew A M MacDonald Diane S Srivastava

Ecological communities hosted within phytotelmata (plant compartments filled with water) provide an excellent opportunity to test ecological theory and to advance our understanding of how local and global environmental changes affect ecosystems. However, insights from bromeliad phytotelmata communities are currently limited by scarce accounts of microfauna assemblages, even though these assembl...

2016
Sarah Q. Foster Robinson W. Fulweiler

Coastal marine ecosystems are generally considered important sources of nitrous oxide (N2O), a powerful greenhouse gas and ozone depleting substance. To date most studies have focused on the environmental factors controlling N2O production although N2O uptake has been observed in a variety of coastal ecosystems. In this study, we examined sediment fluxes of N2O during 2 years (2012–2013) in a s...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Stuart E Jones Jay T Lennon

Dormancy is a bet-hedging strategy used by a variety of organisms to overcome unfavorable environmental conditions. By entering a reversible state of low metabolic activity, dormant individuals become members of a seed bank, which can determine community dynamics in future generations. Although microbiologists have documented dormancy in both clinical and natural settings, the importance of see...

2014
Clive L. Spash Iulie Aslaksen

In this paper we explore the discourses of ecology, environmental economics, new environmental pragmatism and social ecological economics as they relate to the value of ecosystems and biodiversity. Conceptualizing biodiversity and ecosystems as goods and services that can be represented by monetary values in policy processes is an economic discourse being increasingly championed by ecologists a...

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