Conserving Britain's biodiversity. I:Thlaspi perfoliatum L. (Brassicaceae), Cotswold Pennycress
Tóm tắt
This paper describes the decline and conservation work carried out on the rare, statutorily protected species Thlaspi perfoliatum L. (Brassicaceae), Cotswold Pennycress, in England. This plant has been recorded historically in a total of about 45 native and 37 introduced sites. Surveys between 1986 and 1997 found populations in nine native sites and three introduced sites, suggesting an 80% loss of native and 92% loss of introduced colonies. The main reasons for decline are probably agricultural improvements, quarrying and neglect of management. The plant is a winter annual of open grassland and screes on Oolite limestone, which requires maintenance of open conditions for long-term survival. Current and recommended forms of management of sites are outlined. Only two sites have appropriate statutory protection.
Tài liệu tham khảo
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