Distance to seed sources and land-use history affect forest development over a long-termheathland to forest succession

TY - JOUR

T1 - Distance to seed sources and land-use history affect forest development over a long-termheathland to forest succession

AU - Kepfer Rojas, Sebastian

AU - Schmidt, Inger Kappel

AU - Ransijn, Johannes

AU - Riis-Nielsen, Torben

AU - Verheyen, Kris

PY - 2014/11/1

Y1 - 2014/11/1

N2 - Questions: Is there a spatial pattern in the community structure (stem densities, species richness and species composition) of trees and shrubs during more than 100 yr of heathland to forest succession? To what extent is community structure influenced by land-use history and distance to seed sources? Do these effects change in time? Location: A 350-ha heathland (Nørholm) in southwest Denmark was abandoned in 1895 and left for free succession. Prior to abandonment the heathland was under traditionalmanagement for centuries. Method: Trees and shrubs were recorded andmeasured in ten surveys spanning 91 yr (1921-2012). In the first nine surveys, complete censuses were used, whereas 116 randomly placed plots (10-m radius) were used in the most recent survey. We usedmixedmodels and different multivariate techniques (non-metric multidimensional scaling and permutational multivariate ANOVA) to analyse spatio-temporal patterns in stem densities, species richness and species composition and the effects of land-use history and distance to seed sources. Results: Tree and shrub densities increased exponentially over time and were consistently lower at longer distance from seed sources. Land-use history affected the rate of increase in tree densities, with lower encroachment rates at previously cultivated soils. Initially, species richness increased rapidly but leveled off in later successional stages. Richness wasmarginally higher at areas closer to seed sources, whereas it was not affected by land-use history. The succession showed a shift from early to mid-successional species over time; but distance to seed source determined which species were colonizing at early stages. Conclusion: Distance to seed source and land-use history can differentially affect the structure and spatial patterns of developing forest communities. Although both factors had long-lasting effects on rates of colonization, the spatial patterns of colonization and species composition weremainly determined by distance to seed sources. The importance of distance to seed sources became less over time, suggesting that dispersal is a stronger driver at early stages. Aftermore than a century since abandonment, forest covers <30% of the area, indicating that lack of heathland management did not strongly promote tree colonization at this site.

AB - Questions: Is there a spatial pattern in the community structure (stem densities, species richness and species composition) of trees and shrubs during more than 100 yr of heathland to forest succession? To what extent is community structure influenced by land-use history and distance to seed sources? Do these effects change in time? Location: A 350-ha heathland (Nørholm) in southwest Denmark was abandoned in 1895 and left for free succession. Prior to abandonment the heathland was under traditionalmanagement for centuries. Method: Trees and shrubs were recorded andmeasured in ten surveys spanning 91 yr (1921-2012). In the first nine surveys, complete censuses were used, whereas 116 randomly placed plots (10-m radius) were used in the most recent survey. We usedmixedmodels and different multivariate techniques (non-metric multidimensional scaling and permutational multivariate ANOVA) to analyse spatio-temporal patterns in stem densities, species richness and species composition and the effects of land-use history and distance to seed sources. Results: Tree and shrub densities increased exponentially over time and were consistently lower at longer distance from seed sources. Land-use history affected the rate of increase in tree densities, with lower encroachment rates at previously cultivated soils. Initially, species richness increased rapidly but leveled off in later successional stages. Richness wasmarginally higher at areas closer to seed sources, whereas it was not affected by land-use history. The succession showed a shift from early to mid-successional species over time; but distance to seed source determined which species were colonizing at early stages. Conclusion: Distance to seed source and land-use history can differentially affect the structure and spatial patterns of developing forest communities. Although both factors had long-lasting effects on rates of colonization, the spatial patterns of colonization and species composition weremainly determined by distance to seed sources. The importance of distance to seed sources became less over time, suggesting that dispersal is a stronger driver at early stages. Aftermore than a century since abandonment, forest covers <30% of the area, indicating that lack of heathland management did not strongly promote tree colonization at this site.

U2 - 10.1111/jvs.12203

DO - 10.1111/jvs.12203

M3 - Journal article

SN - 1100-9233

VL - 25(6)

SP - 1493

EP - 1503

JO - Journal of Vegetation Science

JF - Journal of Vegetation Science

ER -