Vladislav Popov, Georgi Popgeorgiev, Dimitar Plachiyski, Nedko Nedialkov, Ognian Todorov
Agricultural University of Plovdiv, Bulgaria, 12 ‘Mendeleev’ blvd., 4000 Plovdiv, Bulgaria
Bulgarian Society for Bird Protection, Plovdiv office, Bulgaria
Key words: Agrobiodiversity, organic agriculture, index of Shannon, agroecosystems.
Agrobiodiversity in agroecosystems and their role for maintaining their stability in absence of chemical inputs is not sufficiently investigated in Europe. As a first step in a larger study, this investigation focused on the territory of Eastern Rhodope mountain of Bulgaria in June – September 2012. It tried to compare the impact of organic and conventional agricultural landuse on certain agrobiodiversity indicator groups (insects, birds and small mammals). On the basis of determined taxa density and abundance, and in order to assess and compare biodiversity of the selected indicator groups (insects at the level of order), indices of biodiversity of Shannon (Shannon_H index) and ‘Diversity profiles’ were calculated. The overall biodiversity of the indicator groups in selected organic landuses (cereals, orchard and pasture) was higher (i.e. index of biodiversity Shannon_H and diversity profiles) than in the reference conventional landuses. However, when analysed individually, the three indicator groups showed no statistically significant differences between organic and conventional areas by the index of biodiversity Shannon_H. Nevertheless, a significant difference in exemplar density of class Insecta (2237 exemplars in organic against 712 in conventional landuses) was detected in spring and summer. The results can be attributed to the absence of chemical plant protection inputs in organic cereals and orchards, minimal soil cultivation and the regulated grazing in the organic pastures/meadows. The results are a basis for further more extensive research, comprising a longer period of e.g. 3-4 years, more organic and conventional plots and crops, monitoring agrobiodiversity indicators at the level of species, etc.
Get the original article sin Source: Volume 4, Number 2, February 2014 – JBES