Open AccessVariation in resource exploitation along an altitudinal gradient: the willow psyllids ( Cacopsylla spp.) on Salix lapponum
Author(s) -
Hill Jane K.,
Hamer Keith C.,
Hodkinson Ian D.
Publication year - 1998
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/j.1600-0587.1998.tb00566.x
Subject(s) - willow , altitude (triangle) , range (aeronautics) , biology , transect , botany , salicaceae , abundance (ecology) , ecology , woody plant , geometry , mathematics , materials science , composite material
Three congeneric species of Salix ‐fedding psyllid Cacospsylla spp. Occur along an altitudinal gradient (988 1222 m. a.s.l.) in southern Norway. The 27‐km transect covered the local altitudinal range of the three species. Each species showed a different characteristic altitudinal distribution: C. propinqua occurred over the entire altitudinal range of the transect C. palmeni was restricted to higher altitude and C brunneipennis occurred manly at lower altitudes. This pattern of local altitudinal distribution mirrored the broader geographical distributions of these psyllids along latitudinal gradients. All three species developed on willow catkins, but also made use of leaves. Species differed in their use of leaves with >10% of sampled individuals of C. brunncipennis or C. Palmeni developing on leaves compared with up to 80% in C. propinqua. The proportion of C. propinqua nymphs developing on catkins increased with altitude and was also related to the temporal and spatial availability of catkins but was not a result of competitive displacement from catkins. Nitrogen concentration of host plants did not affect the proportions of C propinqua on leaves or catkins and was not related to adult size or psyllid density on catkins. Patterns or resource use are discussed in relation to differences in the distribution and abundance of the three species along the transect.