Common Kidney Vetch and Fragmentation

 

Common Kidney Vetch, Anthyllis vulneraria

Known to many as a coastal plant in Ireland, Common Kidney Vetch (or Lady's Fingers, Anthyllis vulneraria) is also an important constituent of calcareous grasslands, and it is in this guise that is most common throughout Europe (1). This perennial grows to 40 cm high but tens to a prostrate habit. The pinnate leaves are covered in small hairs, as is the stem and it has densely arranged, yellow to orange flowers (2). The flowers bloom for about 8 days (3), during which time some of the main pollinators are the Long Tongued Bee (Anthophora acervorum) and the bumble bees Bombus terrestris and B. jonellus. Both B. terrestris and B. jonellus are primary nectar robbers, in that they bypass restrictions imposed by flower structures to “rob” nectar (3). This often has deliterious effects on plants, but in the case of A. vulneraria such activity actually results in an increase in fruit production. The structure and arrangements of its flowers means that the bodies of the robbers brushes off the flowers, effecting pollination. Flowers open from the bottom to the top, and interestingly the resultant fruit and seeds are significantly heavier on the bottom compared to those further up (4). A. vulneraria is also the only larval food plant of the butterfly Cupido minimus, and unfortunatley both plant and butterfly are considered endangered in Lower Saxony, Germany (5).

Common Kidney Vetch, Anthyllis vulneraria

A. vulneraria has been recently used to show the effects of fragmentation on populations (1). Fragmentation is the overall reduction and breaking up of an organisms habitat, which itself results in population fragmentation for that organism. While fragmentation is thought to be a cause of speciation (6), populations exposed to it then become vulnerable to extinction (7). A study of populations of A. vulneraria in calcareous grassland exposed to significant fragmentation however, revealed little genetic differentiation between fragment populations. This was due to the nature of the use of the grassland as pasture for sheep. As the sheep move from fragment to fragment, they bring with them on their coats, on their feet and in their dung seeds of A. vulneraria from other locations. These new arrivals help keep a diversity of genetic stock in A. vulneraria populations, reducing any inbreeding depression. This indicates that sustainable management of grazing will help to maintain species diversity in grassland pasture.

References:

1. Honnay et al., 2006. Biological Conservation 127 pp. 411-419
2. Krautzer et al., 2004. Site Specific Grasses and Herbs pp. 13-16
3. Navarro, 2000. American Journal of Botany 87 pp. 980-985
4. Navarro, 1996. Plant Systematics and Evolution 201 pp. 139-148
5. Krauss et al., 2004. Biological Conservation 120 pp. 355-361
6. Sahney et al., 2010. Geoligical Society of America 38 pp. 1079-1082
7. Lande, 1988. Science 241 pp. 1455-1460