In the course of evolution, a great variety of root systems have learned to overcome the many physical, biochemical and biological problems brought about by soil. This development has made them a fascinating object of scientific study. This volume gives an overview of how roots have adapted to the soil environment and which roles they play in the soil ecosystem. The text describes the form and function of roots, their temporal and spatial distribution, and their turnover rate in various ecosystems. Subsequently, a physiological background is provided for basic functions, such as carbon acquisition, water and solute movement, and for their responses to three major abiotic stresses, i.e. hard soil structure, drought and flooding. The volume concludes with the interactions of roots with other organisms of the complex soil ecosystem, including symbiosis, competition, and the function of roots as a food source.

Biological diversity, the variety of living organisms on Earth, is traditionally viewed as the diversity of taxa, and species in particular. However, other facets of diversity also need to be considered for a comprehensive understanding of evolutionary and ecological processes. This novel book demonstrates the advantages of adopting a functional approach to diversity in order to improve our understanding of the functioning of ecological systems and theircomponents. The focus is on plants, which are major components of these systems, and for which the functional approach has led to major scientific advances over the last 20 years. PlantFunctional Diversity presents the rationale for a trait-based approach to functional diversity in the context of comparative plant ecology and agroecology. It demonstrates how this approach can be used to address a number of highly debated questions in plant ecology pertaining to plant responses to their environment, controls on plant community structure, ecosystem properties, and the services these deliver to human societies. This research level text will be of particular relevance and use tograduate students and professional researchers in plant ecology, agricultural sciences and conservation biology.

Plants require a proper balance of matter and energy to maintain their survival and reproduction. Biotic and/or abiotic stresses in diverse environments could influence plant photosynthesis, water and nutrient acquisition and utilization. Through the lens of plant physiological and functional ecology, the study of responses of individual plant traits and/or integration of plant responses to environmental change has been well developed. The variation of plant physiological characteristics and functional traits has been recognized with hundreds of high-quality papers on topics of plant responses to environmental stresses. For now, despite the increasing number of studies trying to establish a linkage between plant physiological processes and functional traits, these covariations have received limited theoretical and experimental verification. This knowledge gap hampers our ability to understand and predict the comprehensive responses of plants to environmental stresses at different scales.

Human activities such as agriculture and mining have led to serious negative effects on biodiversity and important ecosystem services including biodiversity loss and climate change. Thus, it is important to quantify the key determinants of biodiversity, ecosystem functioning and ecological restoration of degraded plant communities in climate change sensitive ecosystems (i.e. subalpine and alpine meadow communities in Qinghai, tropical rainforests and tropical mountains). In this way, effective management, policy and methods can be developed to reduce the influence of climate change on these climate change sensitive ecosystems. The aforementioned human activities continue to destroy and degrade plant communities and ecosystem functioning. Climatic changes further exacerbate negative impacts and may trigger rapid loss of species, precipitate decline and changes in the flows of ecosystem goods and services. As the collective anthropogenic influence intensifies, some ecosystems may be more sensitive than others to these changes. Ecosystems that contribute greatly to human well-being through the delivery of biodiversity and ecosystem benefits should be the focus of particular concern. There are key knowledge gaps on the specific nature of anthropogenic impacts, species and ecosystem responses, and possible management and mitigation measures. Comprehensive documentation of these aspects from highly sensitive regions and ecosystems is urgently needed, particularly at fine scales, which is relevant for developing management and mitigation measures. Pathways such as ecological restoration can offset some of the impacts, but even quantifying the impacts of observed and anticipated changes is far from adequate and other mitigation measures must be considered.

There is a scarcity of detailed information regarding the ecophysiology of root systems and the way root system functioning is affected by both internal and external factors. Furthermore, global climate change is expected to increase the intensity of climate extremes, such as severe drought, heat waves and periods of heavy rainfall; in addition other stresses such as salinization of soils are increasing world-wide. Recently an increasing awareness has developed that understanding plant traits will play a major role in breeding of future crop plants. For example, there is increasing evidence that the traits of root systems are defined by the properties of individual roots. However, further knowledge on the functional importance of root segments and the molecular/physiological mechanisms underlying root system functioning and persistence is needed, and would specifically allow modifying (crop) root system functionality and efficiency in the future. Another major gap in knowledge is localized at the root-soil interface and in regard to the potential adaptive plasticity of root-rhizosphere interactions under abiotic stress and/or competition. It is currently unknown whether adaptations in microbe communities occur, for example due to modified exudation rates, and what are the subsequent influences on nutrient mobilization and uptake. Furthermore, uncovering the mechanisms by which roots perceive neighboring roots may not only contribute to our understanding of plant developmental strategies, but also has important implications on the study of competitive interactions in natural communities, and in optimizing plant performance and resource use in agricultural and silvicultural systems. In this Research Topic, we aimed to provide an on-line, open-access snapshot of the current state of the art of the field of root ecology and physiology, with special focus on the translation of root structure to function, and how root systems are influenced by interplay with internal and external factors such as abiotic stress, microbes and plant-plant interaction. We welcomed original research papers, but reviews of specific topics, articles formulating opinions or describing cutting-edge methods were also gladly accepted.

Trait-based ecology is rapidly expanding. This comprehensive and accessible guide covers the main concepts and tools in functional ecology.

This volume quantifies carbon storage in managed forest ecosystems not only in biomass, but also in all soil compartments. It investigates the interaction between the carbon and nitrogen cycles by working along a north-south transect through Europe that starts in northern Sweden, passes through a N-deposition maximum in central Europe and ends in Italy. For the first time biogeochemical processes are linked to biodiversity on a large geographic scale and with special focus on soil organisms. The accompanying CD-ROM provides a complete database of all flux, storage and species observations for modellers.