Richard D. Bardgett

Bio: Richard D. Bardgett is an academic researcher from University of Manchester. The author has contributed to research in topics: Ecosystem & Soil biology. The author has an hindex of 115, co-authored 381 publications receiving 51685 citations. Previous affiliations of Richard D. Bardgett include Lancaster University & English Nature.

Soil Carbon Dynamics: Trophic interactions and their implications for soil carbon fluxes

Abstract: INTRODUCTION Trophic interactions, the consumption of one organism, or a part of it, by another, are a fundamental component of all ecosystems. The vast majority of net primary productivity is eventually consumed, either by herbivores if the tissue is still alive, or by decomposers if the tissue has died (e.g. Cebrian, 2004). Similarly, these primary consumers are themselves consumed either by predators, parasites or decomposers (secondary consumers). Thus, trophic interactions form the pathways through which carbon flows through an ecosystem and, to a large extent, these interactions control ecosystem carbon dynamics, either directly (via consumption of another organism) or indirectly (e.g. altering competition between the prey individual/population and other organisms). In this chapter we consider the principal ways by which trophic interactions influence soil carbon fluxes (Fig. 10.1). Firstly, we discuss the impacts of both above- and below-ground herbivores on carbon flux into, and out of, the soil and the interactions between herbivores, plants and soil organisms (dashed box in Fig. 10.1). Secondly, we investigate the role of soil fauna in organic matter decomposition, either directly via the consumption of litter, or indirectly via feeding on saprotrophs or the movement of organic matter (dotted box in Fig. 10.1). Thirdly, we examine the role of resource availability versus predation in structuring soil food webs, followed by the linkages between soil biodiversity and a range of ecosystem processes, including plant growth, litter decomposition and carbon mineralization (solid box in Fig. 10.1).

Stoichiometric traits (N:P) of understory plants contribute to reductions in plant diversity following long-term nitrogen addition in subtropical forest.

Abstract: Nitrogen enrichment is pervasive in forest ecosystems, but its influence on understory plant communities and their stoichiometric characteristics is poorly understood. We hypothesize that when forest is enriched with nitrogen (N), the stoichiometric characteristics of plant species explain changes in understory plant diversity. A 13-year field experiment was conducted to explore the effects of N addition on foliar carbon (C): N: phosphorus (P) stoichiometry, understory plant species richness, and intrinsic water use efficiency (iWUE) in a subtropical Chinese fir forest. Four levels of N addition were applied: 0, 6, 12, and 24 g m-2 year-1. Individual plant species were categorized into resistant plants, intermediate resistant plants, and sensitive plants based on their response to nitrogen addition. Results showed that N addition significantly decreased the number of species, genera, and families of herbaceous plants. Foliar N:P ratios were greater in sensitive plants than resistant or intermediate resistant plants, while iWUE showed an opposite trend. However, no relationship was detected between soil available N and foliar N, and soil N:P and foliar N:P ratios. Our results indicated that long-term N addition decreased the diversity of understory plants in a subtropical forest. Through regulating water use efficiency with N addition, sensitive plants change their N:P stoichiometry and have a higher risk of mortality, while resistant plants maintain a stable N:P stoichiometry, which contributes to their survival. These findings suggest that plant N:P stoichiometry plays an important role in understory plant performance in response to environmental change of N.

Local stability properties of complex, species‐rich soil food webs with functional block structure

Abstract: Ecologists have long debated the properties that confer stability to complex, species-rich ecological networks. Species-level soil food webs are large and structured networks of central importance to ecosystem functioning. Here, we conducted an analysis of the stability properties of an up-to-date set of theoretical soil food web models that account both for realistic levels of species richness and the most recent views on the topological structure (who is connected to whom) of these food webs. The stability of the network was best explained by two factors: strong correlations between interaction strengths and the blocked, nonrandom trophic structure of the web. These two factors could stabilize our model food webs even at the high levels of species richness that are typically found in soil, and that would make random systems very unstable. Also, the stability of our soil food webs is well-approximated by the cascade model. This result suggests that stability could emerge from the hierarchical structure of the functional organization of the web. Our study shows that under the assumption of equilibrium and small perturbations, theoretical soil food webs possess a topological structure that allows them to be complex yet more locally stable than their random counterpart. In particular, results strongly support the general hypothesis that the stability of rich and complex soil food webs is mostly driven by correlations in interaction strength and the organization of the soil food web into functional groups. The implication is that in real-world food web, any force disrupting the functional structure and distribution pattern of interaction strengths (i.e., energy fluxes) of the soil food webs will destabilize the dynamics of the system, leading to species extinction and major changes in the relative abundances of species.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Effects of biodiversity on ecosystem functioning: a consensus of current knowledge

Abstract: Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earth's biodiversity cause concern for ethical and aesthetic reasons, but they also have a strong potential to alter ecosystem properties and the goods and services they provide to humanity. Ecological experiments, observations, and theoretical developments show that ecosystem properties depend greatly on biodiversity in terms of the functional characteristics of organisms present in the ecosystem and the distribution and abundance of those organisms over space and time. Species effects act in concert with the effects of climate, resource availability, and disturbance regimes in influencing ecosystem properties. Human activities can modify all of the above factors; here we focus on modification of these biotic controls. The scientific community has come to a broad consensus on many aspects of the re- lationship between biodiversity and ecosystem functioning, including many points relevant to management of ecosystems. Further progress will require integration of knowledge about biotic and abiotic controls on ecosystem properties, how ecological communities are struc- tured, and the forces driving species extinctions and invasions. To strengthen links to policy and management, we also need to integrate our ecological knowledge with understanding of the social and economic constraints of potential management practices. Understanding this complexity, while taking strong steps to minimize current losses of species, is necessary for responsible management of Earth's ecosystems and the diverse biota they contain.

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Biodiversity loss and its impact on humanity

Abstract: The most unique feature of Earth is the existence of life, and the most extraordinary feature of life is its diversity. Approximately 9 million types of plants, animals, protists and fungi inhabit the Earth. So, too, do 7 billion people. Two decades ago, at the first Earth Summit, the vast majority of the world's nations declared that human actions were dismantling the Earth's ecosystems, eliminating genes, species and biological traits at an alarming rate. This observation led to the question of how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper.

Climate Change 2007: The Physical Science Basis.

Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.