Extinction Debt of Forest Plants Persists for More Than a Century Following Habitat Fragmentation

Abstract

Following habitat fragmentation individual habitat patches may lose species over time as they pay off their "extinction debt." Species with relatively low rates of population extinction and colonization ("slow" species) may maintain extinction debts for particularly prolonged periods, but few data are available to test this prediction. We analyzed two unusually detailed data sets on forest plant distributions and land-use history from Lincolnshire, United Kingdom, and Vlaams-Brabant, Belgium, to test for an extinction debt in relation to species-specific extinction and colonization rates. Logistic regression models predicting the presence-absence of 36 plant species were first parameterized using data from Lincolnshire, where forest cover has been relatively low (approximately 5-8%) for the past 1000 years. Consistent with extinction debt theory, for relatively slow species (but not fast species) these models systematically underpredicted levels of patch occupancy in Vlaams-Brabant, where forest cover was reduced from approximately 25% to <10% between 1775 and 1900 (it is presently 6.5%). As a consequence, the ability of the Lincolnshire models to predict patch occupancy in Vlaams-Brabant was worse for slow than for fast species. Thus, more than a century after forest fragmentation reached its current level an extinction debt persists for species with low rates of population turnover.

Testing coexistence of extinction debt and colonization credit in fragmented calcareous grasslands with complex historical dynamics

“…A lack of colonization credit was also found by Cristofoli et al (2010b) in new patches of another semi-natural temperate habitat: wet heathlands. This pattern sharply differs with results found for woodlands where colonization credit may persist for more than one century (Vellend et al 2006). …”

Assessing ecological habitat structure from local to landscape scales using synthetic aperture radar

“…This would be useful to address questions on extinction or colonization debts, i.e. the fact that landscapes and species distributions do not change at the same rate (Vellend et al, 2006).…”

Remnant Populations and Plant Functional Traits in Abandoned Semi-Natural Grasslands

“…To examine whether an extinction debt actually exists, we require either data on species loss following habitat fragmentation (e.g., Helm et al 2006) or data from multiple similar landscapes with varying histories of fragmentation (Berglund and Jonsson 2005;Vellend et al 2006). Scarcity of these kinds of data has resulted in few empirical studies that underpin the existence of extinction debts in natural populations.…”

“…contributing to an extinction debt (Vellend et al 2006). Dispersal strategies and lifecycle characteristics, for example, might cause some species to have lower rates of stochastic extinctions, while other species showing higher rates of stochastic population extinction are expected to pay off their extinction debt quite rapidly (Ovaskainen and Hanski 2002).…”

“…Identifying extinction debts and remnant populations is important when assessing the degree to which biological surveys provide accurate estimates of the capacity of landscapes to maintain biodiversity. It is also important to study the time-period it takes for a population or a community to come into equilibrium with a given landscape structure following disturbance (Vellend et al 2006).…”