Restoration of Biodiversity and Ecosystem

Abstract

Succession is one of the most studied processes in ecology and succession theory provides strong predictability. However, few attempts have been made to influence the course of succession thereby testing the hypothesis that the passage of one stage is essential to enter a next one. At each stage of succession ecosystem processes may be affected by the diversity of species present, but there is little empirical evidence showing that plant species diversity may affect succession. The main objective in the present study is to test if there is any effect of plant species diversity on the functioning of artificially-created grassland communities. We were mostly interested in how successful is the sowing of meadow species into newly abandoned land and how long do the effect of initial sowing persist, how is affected the set of natural colonizers, which includes both the weed species and also the later successional species arriving naturally into the zone. One of the main questions concerning succession is to which extent the trajectory may be predictable or not. What will be the consequence of the different succession pathways for ecosystem processes, such as productivity and resource utilization, as well as species composition of both above and belowground communities? What will be the subsequent effects of feed back to vegetation development through initial manipulation of vegetation after land abandonment? And, finally, how general may results be when obtained in specific conditions? Our hypothesis is that an increase in the initial plant species diversity at the start of secondary succession enhances the amount of biomass produced and consequently stimulates the soil microbial biomass and the abundance of soil invertebrates. It has been suggested that changes in plant species diversity affect several ecosystem processes, such as primary productivity, nutrient retention and vegetation dynamics. A positive impact of species diversity on plant productivity has been explained by the complementarity of resource use among plant species or their functional groups.