Long-Term Studies of Vegetation Dynamics

Abstract

By integrating a wide range of experimental, comparative, and theoretical approaches, ecologists are starting to gain a detailed understanding of the long-term dynamics of vegetation. We explore how patterns of variation in demographic traits among species have provided insight into the processes that structure plant communities. We find a common set of mechanisms, derived from ecological and evolutionary principles, that underlie the main forces shaping systems as diverse as annual plant communities and tropical forests. Trait variation between species maintains diversity and has important implications for ecosystem processes. Hence, greater understanding of how Earth's vegetation functions will likely require integration of ecosystem science with ideas from plant evolutionary, population, and community ecology.The past decade has seen the emergence of a new synthesis in plant ecology that draws together a variety of once disparate approaches in studies of vegetation dynamics. Questions about the determinants of plant life histories, species composition, diversity, productivity, and stability-previously considered separate areas of inquiry-have become increasingly closely integrated. Findings from long-term experimental and observational studies, combined with comparative and theoretical work, have helped synthesize the questions and approaches of evolutionary ecology, population ecology, and ecosystem ecology. The link has come from the realization that many of the same environmental constraints and organismal tradeoffs that shape the evolution of plant morphologies, life histories, and physiologies also influence the dynamics of interspecific interactions and the mechanisms of coexistence that control community and ecosystem functioning (1-3). We provide a brief tour of the developments in vegetation science, highlighting areas where known patterns of variation in demographic rates between species have provided insights into the structure, dynamics, and functioning of plant communities.

Variações temporais na comunidade arbórea de uma floresta decidual sobre afloramentos calcários no Brasil Central: composição, estrutura e diversidade florística

“…Considerando a disponibilidade hídrica como o fator mais limitante nas fl orestas estacionais (Murphy & Lugo 1986), é provável que esta alternância na precipitação anual exerça forte infl uência na dinâmica, intercalando períodos de maior ou menor mortalidade, ocasionando fl utuações no balanço entre mortalidade e recrutamento. Tais fl utuações são comuns em fl orestas tropicais (Phillips et al 1994;Rees et al 2001;Lewis et al 2004a,b), e já foram registradas em vários estudos de dinâmica em longo prazo em vegetações sob climas estacionais (Felfi li 1995 a,b;Higuchi et al 2008).…”

Tree Diversity Changes over a Decade (2003-2013) in Four Inland Tropical Dry Evergreen Forest Sites on the Coromandel Coast of India

“…As in all other ecosystems, tropical forests too face a wide range of disturbances of variable duration, intensity and frequency. Long-term vegetation monitoring has been undertaken in various tropical forests around the world (Rees et al 2001;Laurance et al 2004;Weckel et al 2006;Marimon et al 2012;van den Berg et al 2012;Ge et al 2013), and an increasing number of studies have shown that forests have undergone dynamic widespread directional shifts in composition and structure (Enquist and Enquist 2011;Feeley et al 2011;Peng et al 2011;Fauset et al 2012;Kucbel et al 2012). Long-term monitoring of permanent forest plots provides data to assess aboveground standing biomass stock and C dynamics and assesses the response of the forest to the environmental drivers such as elevated temperature, CO 2 fertilization, increase in incoming solar radiation and nitrogen enrichment (Bhat and Ravindranath 2011).…”

Plant functional traits have globally consistent effects on competition

“…Low wood density was also correlated with a low ability to tolerate competition and a low competitive effect on neighbours, while high specific leaf area was correlated with a low competitive effect. Thus, traits generate trade-offs between performance with competition versus performance without competition, a fundamental ingredient in the classical hypothesis that the coexistence of plant species is enabled via differentiation in their successional strategies 5 . Competition within species was stronger than between species, but an increase in trait dissimilarity between species had little influence in weakening competition.…”

“…The parameters m 0 , m 1 , α 0intra , α 0inter , α e , α t and α d are fitted from data using a maximum likelihood method. Letter reSeArCH stages where competitors are absent or rare, and are later replaced by slow-growing species in late successional stages where competitors become more abundant 5 . Human or natural disturbances are conspicuous in all of the forests analysed, hence successional dynamics are likely to be present in all these sites (see Supplementary Information).…”