This book discusses advanced statistical methods that can be used to analyse ecological data. Most environmental collected data are measured repeatedly over time, or space and this requires the use of GLMM or GAMM methods. The book starts by revising regression, additive modelling, GAM and GLM, and then discusses dealing with spatial or temporal dependencies and nested data.

Perspectives on Plant Competition is mainly about addressing the many different perspectives in plant competition and finding a common ground among them. Its aim is that through this common ground, new theories can be created. Encompassing 20 chapters, this book is divided into three parts. Part I, Perspectives on the Determinants of Competitive Success, consists of eight chapters. This section deals mainly on the question of determination of competitive success. Different writers put forward various definitions of competition and competitive success to shed light on the question at hand. In the second part of this book, an opposing set of views regarding the consequences of competitive interactions for the plant community structure is provided. This section emphasizes the idea that competition is not the sole force in natural communities. Each chapter in this part focuses on a certain aspect of competition as seen in different communities – across and within habitats – and systems. Part III, which comprises of four chapters, focuses on the competition within the context of interaction of plants with organisms on the other trophic levels. The chapters set forth the idea that competition depends on the impacts of herbivores, parasites, and symbionts. The concluding part of the book greatly emphasizes the need to integrate the mechanisms of competition into the framework of the entire food web.

Competitiveness describes a key ability important for plants to grow and survive abiotic and biotic stresses. Under optimal, but particularly under non-optimal conditions, plants compete for resources including nutrients, light, water, space, pollinators and other. Competition occurs above- and belowground. In resource-poor habitats, competition is generally considered to be more pronounced than in resource-rich habitats. Although competition occurs between different players within an ecosystem such as between plants and soil microorganisms, our topic focusses on plant-plant interactions and includes inter-specific competition between different species of similar and different life forms and intra-specific competition. Strategies for securing resources via spatial or temporal separation and different resource needs generally reduce competition. Increasingly important is the effect of invasive plants and subsequent decline in biodiversity and ecosystem function. Current knowledge and future climate predictions suggest that in some situations competition will be intensified with occurrence of increased abiotic (e.g. water and nutrient limitations) and biotic stresses (e.g. mass outbreak of insects), but competition might also decrease in situations where plant productivity and survival declines (e.g. habitats with degraded soils). Changing interactions, climate change and biological invasions place new challenges on ecosystems. Understanding processes and mechanisms that underlie the interactions between plants and environmental factors will aid predictions and intervention. There is much need to develop strategies to secure ecosystem services via primary productivity and to prevent the continued loss of biodiversity. This Research Topic provides an up-to-date account of knowledge on plant-plant interactions with a focus on identifying the mechanisms underpinning competitive ability. The Research Topic aims to showcase knowledge that links ecological relevance with physiological processes to better understanding plant and ecosystem function.