University of York

About: University of York is a education organization based out in York, York, United Kingdom. It is known for research contribution in the topics: Population & Health care. The organization has 22089 authors who have published 56925 publications receiving 2458285 citations. The organization is also known as: York University & Ebor..

The plastic plant: root responses to heterogeneous supplies of nutrients

Abstract: Contents I. Introduction 000 II. Morphological responses 000 III. Root demography 000 IV. Physiological plasticity 000 V. Root plasticity in patches in competition and symbiosis with microorganisms 000 VI. Influence of patch attributes 000 VII. Control of root proliferation 000 VIII. Conclusions 000 Acknowledgements 000 References 000 Summary When roots encounter a nutrient-rich zone or patch they often proliferate within it. Roots experiencing nutrient-rich patches can also enhance their physiological ion-uptake capacities compared with roots of the same plant outside the patch zone. These plastic responses by the root system have been proposed as the major mechanism by which plants cope with the naturally occurring heterogeneous supplies of nutrients in soil. Various attempts to predict how contrasting species will respond to patches have been made based on specific root length (SRL), root demography and biomass allocation within the patch zone. No one criterion has proved definitive. Actually demonstrating that root proliferation is beneficial to the plant, especially in terms of nitrogen capture from patches, has also proved troublesome. Yet by growing plants under more realistic conditions, such as in interspecific plant competition, and with a complex organic patch, a direct benefit can be demonstrated. Thus, as highlighted in this review, the environmental context in which the root response is expressed is as important as the magnitude of the response itself.

Plan 9 From Cyberspace: The Implications of the Internet for Personality and Social Psychology:

Abstract: Just as with most other communication breakthroughs before it, the initial media and popular reaction to the Internet has been largely negative, if not apocalyptic. For example, it has been described as “awash in pornography”, and more recently as making people “sad and lonely.” Yet, counter to the initial and widely publi cized claim that Internet use causes depression and social isolation, the body of ev idence (even in the initial study on which the claim was based) is mainly to the con trary. More than this, however, it is argued that like the telephone and television before it, the Internet by itself is not a main effect cause of anything, and that psy chology must move beyond this notion to an informed analysis of how social iden tity, social interaction, and relationship formation may be different on the Internet than in real life. Four major differences and their implications for self and identity, social interaction, and relationships are identified: one's greater anonymity, the greatly reduced i...

Biodiversity and ecosystem services: a multilayered relationship

Abstract: The relationship between biodiversity and the rapidly expanding research and policy field of ecosystem services is confused and is damaging efforts to create coherent policy. Using the widely accepted Convention on Biological Diversity definition of biodiversity and work for the UK National Ecosystem Assessment we show that biodiversity has key roles at all levels of the ecosystem service hierarchy: as a regulator of underpinning ecosystem processes, as a final ecosystem service and as a good that is subject to valuation, whether economic or otherwise. Ecosystem science and practice has not yet absorbed the lessons of this complex relationship, which suggests an urgent need to develop the interdisciplinary science of ecosystem management bringing together ecologists, conservation biologists, resource economists and others.