Effects of agricultural activities on insect species richness in the intensively cultivated landscape of Quzhou County, North China Plain UCL-China Research Festival - Video

As signatory of the Convention on Biological Diversity (CBD), China supports the 2010 Biodiversity Target to achieve a significant reduction in the current rate of biodiversity loss by the year 2010. This very ambitious goal must be seen against the background of a huge knowledge gap prevailing particularly with regard to patterns of insect diversity in space and time.

Our collaborative research is trying to be instrumental in addressing the aforementioned knowledge gap by investigating how different agricultural activities affect species richness in a number of different habitats which are characterized by very different intensities of agricultural management. The research is conducted at the Agricultural Research Station of the China Agricultural University in Quzhou county, an area heavily utilized for agricultural production with only very small remnants of semi-natural habitats remaining.

In this setting, the diversity of beetles and plants is compared between semi-natural woodland habitats, orchards which are managed at intermediate intensity, lawn, intensively managed fields of winter wheat/summer maize and cotton monocultures. Species richness of plants peaks at the habitats which are managed extensively, with similar levels of diversity being recorded in woodland and orchards. Diversity of carabid beetle communities is lowest at cotton monocultures followed by lawns, but shows equally high values in woodlands, orchards and intensively managed wheat/maize fields.

An investigation of changes in species composition between different habitats reveals that cotton and wheat/maize fields harbour similar beetle assemblages. These are nonetheless distinctly different from assemblages encountered in orchard and woodland areas. This leads to the conclusion that a further intensification of agricultural practices, but especially the ongoing transformation of orchards and wheat/maize fields into cotton monocultures which can be observed in large sections of the study area, has the potential to severely decrease the overall species pool of both carabid beetles and plant species. On the other hand, the high degree of similarity in the species composition of ground beetles and plant species in orchards and semi-natural woodland hints at the possibility that the promotion of orchards in the Quzhou district might be a highly feasible approach in preserving a significant proportion of the local species pool.