نتایج جستجو برای: ecological integrity

تعداد نتایج: 169874  

2017
P Anders Nilsson Kaj Hulthén Ben B Chapman Lars-Anders Hansson Jakob Brodersen Henrik Baktoft Jerker Vinterstare Christer Brönmark Christian Skov

Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre- and/or post-zygotic reproductive barriers. Ecological selection, including predation, is often p...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2000
W J Trush S M McBain L B Leopold

Rivers around the world are being regulated by dams to accommodate the needs of a rapidly growing global population. These regulatory efforts usually oppose the natural tendency of rivers to flood, move sediment, and migrate. Although an economic benefit, river regulation has come at unforeseen and unevaluated cumulative ecological costs. Historic and contemporary approaches to remedy environme...

2017
Deusiano Florêncio dos Reis Ayala Eduardo Salazar Mayana Mendes Dias Machado Sheyla Regina Marques Couceiro Paula Benevides de Morais

Generally, aquatic communities reflect the effects of anthropogenic changes such as deforestation or organic pollution. The Cerrado stands among the most threatened ecosystems by human activities in Brazil. In order to evaluate the ecological integrity of the streams in a preserved watershed in the Northern Cerrado biome corresponding to a mosaic of ecosystems in transition to the Amazonia biom...

2011
Jonas Linderoth

This paper outlines a framework for understanding gameplay from the perspective of ecological psychology. According to this perspective, gameplay can be described in terms of perceiving, acting on and transforming the affordances that are related to a game system or to other players in a game. Challenges in games have an emphasis on perceiving suitable actions and/or performing suitable actions...

پایان نامه :0 1371

in order to examine the ecological conditions and characteristics of fraxinus excelsior l. in the northern forests of iran 6 main areas as well as some miscellaneous ones , have been selected in the region respectively in : lomir2, shafaroud , park - e-noor , ahlam , alandan and noor.

Journal: :Environmental monitoring and assessment 2013
Michael H Kido

Based upon ecological data provided by a 6-year study of native species assemblage structure and function in near-pristine Limahuli Stream (Kauai), The Hawaii Stream Index of Biological Integrity (HS-IBI) incorporates 11 metrics covering five ecological categories (taxonomic richness, sensitive species, reproductive capacity, trophic-habitat capacity, and tolerance capacity). The HS-IBI was sho...

2017
Les G Firbank Chiara Bertora David Blankman Gemini Delle Vedove Mark Frenzel Carlo Grignani Elli Groner Miklós Kertész Eveline J Krab Giorgio Matteucci Christina Menta Carsten W Mueller Jutta Stadler William E Kunin

The study of ecosystem processes over multiple scales of space and time is often best achieved using comparable data from multiple sites. Yet, long-term ecological observatories have often developed their own data collection protocols. Here, we address this problem by proposing a set of ecological protocols suitable for widespread adoption by the ecological community. Scientists from the Europe...

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