Patterns and Mechanisms of Plant Diversity in Forested Ecosystems: Implications for Forest Management

Abstract

The objectives of this paper are to (1) review existing diversity models, (2) identify principles that explain patterns of plant species diversity, (3) discuss implications for forest management, and (4) identify research needs. Many current theories cast disturbance as the key player in maintaining species diversity by preventing competitive dominance of one or a few species. Equilibrium and nonequilibrium theories alike agree that maximum diversity should occur at intermediate size, frequency, and intensity of disturbance. These models do not adequately predict patterns at all spatial scales or across community types. A mechanistic theory is needed to explain diversity patterns at the patch, stand, and landscape scales, as well as across site quality and successional gradients. Such a theory should be based upon the interaction between species' life‐history characteristics and the nature of disturbance. New research is needed in the following areas: identifying disturbance‐life‐history interactions, particularly with respect to the short‐term and long‐term effects of disturbance; quantifying patch diversity and determining its relationship with species diversity; determining relationships between species diversity and structural and functional diversity; and identifying appropriate standards of comparison for managed stands. Comparative studies in different ecosystem types, such as boreal and tropical forests, should be encouraged to help clarify the relative importance of processes that influence diversity.

Lantana Camara L. Invasion and Impact on Herb Layer Diversity and Soil Properties in a Dry Deciduous Forest of India

“…F., Sida cordifolia L., Sida rhombifolia L., Tephrosia purpurea Pers. which decrease and ultimately get locally extinct with increasing level of lantana cover may not recover quickly because of the altered physical environmental conditions (Roberts and Gilliam, 1995). Species which are unique (Alysicarpus vaginalis (L.) DC, Andrographis echioides Nees., Begonia picta Sm., Ceropegia bulbosa L., Cyanotis axillaris Schult., Justicia simplex Don.…”

The mammalian communities in coffee plantations around a protected area in the Western Ghats, India

“…A fundamental concern gets lost in this debate: one cannot assume that anthropogenic disturbances are necessarily equivalent to natural disturbances in their effects on ecosystem processes. For anthropogenic disturbances to mimic natural disturbances, they must also occur at the same spatial and temporal scales as natural disturbances (Roberts and Gilliam 1995). With evidence pointing to increasing frequency of anthropogenic fires today, it is more than likely that these fires are qualitatively different in their effect on ecosystems from fires in the past.…”

Community structure of vascular plants in treefall gaps and fire-disturbed habitats in the Atlantic rainforest, southern Bahia, Brazil

“…Some sucessional models attempt to explain this lack of significant differences (Connell 1978, Roberts & Gilliam 1995, Guariguata & Ostertag 2001. These models predict a rapid recovery of species richness in areas that have suffered only moderate disturbance, although with a different species composition, dominated at first by fast-growing, short-lifespan species.…”