ABSTRACT
Biodiversity experiments have shown that species loss reduces ecosystem functioning in grassland. To test whether this result can be extrapolated to forests, the main contributors to terrestrial primary productivity, requires large-scale experiments. We manipulated tree species richness by planting more than 150,000 trees in plots with 1 to 16 species. Simulating multiple extinction scenarios, we found that richness strongly increased stand-level productivity. After 8 years, 16-species mixtures had accumulated over twice the amount of carbon found in average monocultures and similar amounts as those of two commercial monocultures. Species richness effects were strongly associated with functional and phylogenetic diversity. A shrub addition treatment reduced tree productivity, but this reduction was smaller at high shrub species richness. Our results encourage multispecies afforestation strategies to restore biodiversity and mitigate climate change.
Subject(s)
Biodiversity , Climate Change , Extinction, Biological , Forests , Trees/classification , Carbon/analysis , Phylogeny , Trees/physiologyABSTRACT
Based on the layer of non-agricultural land expansion interpreted from 4 Landsat TM images in 1984, 1995, 2000 and 2003 and the soil quality map, the patterns of non-agricultural land expansion occurring on soil quality levels in Suzhou City were analyzed. It was indicated that the non-agricultural land expansion happened mainly on the soils with high quality during 1984-2003. 90% of the expansion took place on the soils with moderately high quality (grade 2), and the next was those with high quality (grade 1). In the meanwhile, the expansion on the soils with moderate (grade 3) and low quality (grade 4) was only less than 1% of total area. From the viewpoint of soil quality, we should ponder more over the opinion on "dynamic balance of total amount of arable land between occupying and supplementing".
