Effects of pollution-induced habitat disturbance on the response of willows to simulated herbivory

Citation
El. Zvereva et Mv. Kozlov, Effects of pollution-induced habitat disturbance on the response of willows to simulated herbivory, J ECOLOGY, 89(1), 2001, pp. 21-30
Citations number
68
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
JOURNAL OF ECOLOGY
ISSN journal
0022-0477 → ACNP
Volume
89
Issue
1
Year of publication
2001
Pages
21 - 30
Database
ISI
SICI code
0022-0477(200102)89:1<21:EOPHDO>2.0.ZU;2-A
Abstract
1 Stress may affect compensatory plant growth and plant responses to herbiv ory may therefore be modified by pollution. We compared the effects of leaf clipping on growth, reproduction and developmental stability of two willow species (Salix borealis and S. caprea) growing at different distances from two copper-nickel smelters (Monchegorsk, NW Russia and Harjavalta, SE Finl and). 2 In unpolluted sites, the defoliation of both willow species adversely aff ected sexual reproduction and increased the formation of epicormic shoots, but did not change either shoot growth or leaf size. Timing and extent of c lipping had little effect on the responses. 3 Compensatory responses to leaf clipping in polluted habitats were reduced , especially in S. borealis, as reflected by decrease in shoot growth and f ruit production and an increase in leaf fluctuating asymmetry, a non-specif ic indicator of stress. 4 Activation of dormant buds was a common compensatory response to herbivor y in unpolluted sites. The lack of an increase in epicormic shoots in pollu ted sites may be due to already weakened apical dominance. 5 Compensatory abilities may be affected both by direct damage caused by po llutants and pollution-induced increases in environmental stress. Although S. borealis shows no visible sign of stress in polluted sites, regrowth fro m dormant buds and enhanced shoot growth were seen under these conditions. Resources were not therefore available for further compensation of damage c aused by defoliation. Our results fit the hypothesis that fast growing plan ts have low compensative abilities. 6 Salix caprea shows more pollution-induced stress than S. borealis, expres sed as increased developmental instability near the weaker and shorter shoo ts near the stronger pollution source. This may explain the differences in their compensatory responses in polluted sites.