his project, conducted in collaboration with Prof. Juha Helenius (Department of Plant Production, University of Helsinki), Prof. Sirpa Kurppa (Agricultural Research Centre MTT), Drs. Mikko Kuussaari and Seppo Rekolainen (Finnish Environment Institute) and Dr. Jukka Salonen (Agricultural Research Centre MTT), and their research teams, was started in 1997 and briefly described in Lammi Notes 25:18-19. Field research carried out at the Biological Station in 1999 with some preliminary results were as follows: (1) Breeding bird population monitoring was continued on permanent farmland study plots (ca. 1300 ha). Moreover, for the purpose of studying the impact of the Finnish Agri-environmental Support Scheme (1995-99), the study area censused was doubled to include plots which were first censused in 1995-97. Data from 1984-99 for one species, the Skylark Alauda arvensis, were analysed with older data from Lammi and other localities. This showed that the population has fluctuated strongly d u ring the past 60 years. The population increased twofold in the 1970s, decreased to the former level in the 1980s, increased by 60 % in the 1990s, but decreased again to the original level at the end of the decade. The fluctuations were connected to large-scale set-aside of fields with green cover. The Skylark density is relatively high in Finland as a consequence of relatively small mean field size and variation in the use of neighbouring fields. During the past few decades crop variation has been lost, but set-asides have compensated the loss. (2) Sampling in spring cereal fields and in field margins of organic farms, conventional cereal farms and conventional dairy farms was continued for a study on the effect of the farming system on weeds, and on bumblebees and other pollinating insects. Diversity differences have been clear with organic farms supporting more diverse fauna and flora. Analyses of data from earlier years have included carabid community variation at differen t level s of spatial scale from within a field through between fields to between patches of farmland. The farmland carabid community consists of some 70-80 species. The similarity of community composition among fields is more dependant on distance than crop type. Communities do not differ only between patches of farmland isolated by forest from each other, but the are increasingly different within a patch the farther from each other they are situated. Among crop types, communities in fields with year-round vegetation differ from those which are tilled in spring. Among fields tilled in spring, communities in potato are most different. Another analysis of bumblebee and cuckoo bumblebee abundance and species richness revealed differences among patches of farmland, which are explained by landscape elements (especially density in meters/ha and width of field margins) and the abundance and diversity of flowering dicot plants, especially Trifolium medium, Epilobium angustifolium and Cirsium a rvense.
Tulokset
tutkimus on käynnissä
Vastaava tutkija
Tianen Juha, Helsingin yliopisto, Lammin biologinen asema Hankkeen kesto 1997 -
Asiasanat
Biodiversiteetti, maatalous, ympäristötutkimus, alueellinen vaihtelu, ajallinen vaihtelu, viljely
Hankkeen vaihe: päättynyt
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