Causes and consequences of variation in plant population growth rate: a synthesis of matrix population models in a phylogenetic context

Abstract

Explaining variation in population growth rates is fundamental to predicting population dynamics and population responses to environmental change. In this study, we used matrix population models, which link birth, growth and survival to population growth rate, to examine how and why population growth rates vary within and among 50 terrestrial plant species. Population growth rates were more similar within species than among species; with phylogeny having a minimal influence on among-species variation. Most population growth rates decreased over the observation period and were negatively autocorrelated between years; that is, higher than average population growth rates tended to be followed by lower than average population growth rates. Population growth rates varied more through time than space; this temporal variation was due mostly to variation in post-seedling survival and for a subset of species was partly explained by response to environmental factors, such as fire and herbivory. Stochastic population growth rates departed from mean matrix population growth rate for temporally autocorrelated environments. Our findings indicate that demographic data and models of closely related plant species cannot necessarily be used to make recommendations for conservation or control, and that post-seedling survival and the sequence of environmental conditions are critical for determining plant population growth rate.

The role of transient dynamics in stochastic population growth for nine perennial plants

“…The asymptotic behavior of the model is described by the dominant eigenvalue of the matrix (k 0 ), where log k 0 indicates the eventual exponential population growth rate, and the eigenvector associated with k 0 yields the SSD for the population. In recent years, awareness of the importance of incorporating environmental stochasticity in matrix models has increased, with many developments for including environmental stochasticity in stage-based population models (Kaye and Pyke 2003, Tuljapurkar et al 2003, Boyce et al 2006, Buckley et al 2010.…”

“…Demographic matrix models, in particular, have an extensive literature concerning the role of environmental stochasticity (Kaye and Pyke 2003, Tuljapurkar et al 2003, Buckley et al 2010. Matrix population models are used to represent populations where different size or age classes of individuals (e.g., flowering vs. vegetative plants) have different demographic rates (Caswell 2001, Morris andDoak 2002).…”

Evaluating the causal basis of ecological success within the scleractinia: an integral projection model approach

“…Temporal variation in population growth rates was mostly due to variation in post-seedling survival (rather than adult fecundity), herbivory, and fire (Buckley et al 2010). An analysis such as that utilized by Buckley et al (2010) could be used to good effect with tropical reef corals, specifically to identify ecological winners and losers in communities exposed to disturbances such as storms, predatory sea stars, thermal stress, and OA.…”

“…An analysis such as that utilized by Buckley et al (2010) could be used to good effect with tropical reef corals, specifically to identify ecological winners and losers in communities exposed to disturbances such as storms, predatory sea stars, thermal stress, and OA. Compared to research in other systems, demographic studies on corals are rare.…”

“…In terrestrial plants, for example, much demographic data are available to assess the patterns and process of population growth. Buckley et al (2010) synthesized demographic models having both spatial and temporal replication from 50 species, with multiple populations (≥2) per species and multiple matrices (≥2) per population. They identified the species for which population growth rates declined through time, as well as the sources of variation in population growth rates among species.…”