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- De Frenne, P, et al.
(författare)
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Unraveling the effects of temperature, latitude and local environment on the reproduction of six forest herbs.
- 2009
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 18:6, s. 641-651
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Tidskriftsartikel (refereegranskat)abstract
- Aim To investigate the effect of temperature, latitude and local environment on the reproductive traits of widespread perennial forest herbs to better understand the potential impacts of rising temperatures on their population dynamics and colonization capacities.Location Six regions along a latitudinal gradient from France to Sweden.Methods Within each region, we collected data from three to five populations of up to six species. For each species, several variables were recorded in each region (temperature, latitude) and population (local abiotic and biotic environmental variables), and seed production and germination were estimated. Resource investment in reproduction (RIR) was quantified as seed number × seed mass, while germinable seed output (GSO) was expressed as seed number × germination percentage. We performed linear regression and mixed effect models to investigate the effects of temperature (growing degree hours), latitude and local abiotic and biotic environment on RIR and GSO.Results Temperature and latitude explained most of the variation in RIR and GSO for early flowering species with a northerly distribution range edge (Anemone nemorosa, Paris quadrifolia and Oxalis acetosella). Reproduction of the more southerly distributed species (Brachypodium sylvaticum, Circaea lutetiana and Primula elatior), in contrast, was independent of temperature/latitude. In the late summer species, B. sylvaticum and C. lutetiana, variation in RIR and GSO was best explained by local environmental variables, while none of the investigated variables appeared to be related to reproduction in P. elatior.Main conclusions We showed that reproduction of only two early flowering, northerly distributed species was related to temperature. This suggests that the potential reproductive response of forest herbs to climate warming partly depends on their phenology and distribution, but also that the response is to some extent species dependent. These findings should be taken into account when predictions about future shifts in distribution range are made.
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- Vellend, Mark, et al.
(författare)
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Homogenization of forest plant communities and weakening of species–environment relationships via agricultural land use
- 2007
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 95, s. 565-573
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Tidskriftsartikel (refereegranskat)abstract
- 1Disturbance may cause community composition across sites to become more or less homogenous, depending on the importance of different processes involved in community assembly. In north-eastern North America and Europe local (alpha) diversity of forest plants is lower in forests growing on former agricultural fields (recent forests) than in older (ancient) forests, but little is known about the influence of land-use history on the degree of compositional differentiation among sites (beta diversity).2Here we analyse data from 1446 sites in ancient and recent forests across 11 different landscapes in north-eastern North America and Europe to demonstrate decreases in beta diversity and in the strength of species–environment relationships in recent vs. ancient forests.3The magnitude of environmental variability among sites did not differ between the two forest types. This suggests the difference in beta diversity between ancient and recent forests was not due to different degrees of environmental heterogeneity, but rather to dispersal filters that constrain the pool of species initially colonizing recent forests.4The observed effects of community homogenization and weakened relationships between species distributions and environmental gradients appear to persist for decades or longer. The legacy of human land-use history in spatial patterns of biodiversity may endure, both within individual sites and across sites, for decades if not centuries.
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