Herbivore Effect on Stature, Fruiting, and Leaf Dynamics of a Native Crucifer
نویسنده
چکیده
The impact of a native, leaf-feeding chrysomelid beetle (Phaedon sp. nr. oviformis) on bittercress (Cardamine cordifolia: Cruciferae), was evaluated in an exclusion experiment. Multivariate statistical analysis showed a significant increase in plant performance in the rotenone exclusion compared to performance in the paired control treatment. Plant response to the reduction of herbivory was a complicated, interrelated syndrome of changes. When insects were excluded, the amount of missing leaf area decreased significantly (3.6-fold; 3.2-0.9 cm2 per plant), and the total leaf area increased 5.7-fold (12.9-73.4 cm2 per plant). Plant height (5.7-20.3 cm) and fruit production (0.13.9 siliques per plant) also increased significantly when the number of insects was reduced. Furthermore, the 570% expansion in leaf area due to the exclusion of insects involved significant increases both in the initiation of new leaves and in the survival of mature leaves. Nevertheless, insect herbivory at a level well below complete defoliation (25% of the leaf area) changed leaf demography (both phenology and dynamics) and reduced plant performance by decreasing the plant stature, leaf area, and fruit production of this native forb. Thus, further experimental assessment is necessary before generalizations can be made regarding the effects of herbivory on plant dynamics.
منابع مشابه
Plant Resistance to Insect Herbivores: A Field Test of the Environmental Stress Hypothesis
We tested the hypothesis that environmental stresses decrease overall plant resistance to insect herbivory in the field and evaluated biochemical mechanisms proposed to explain insect response to stressed plants. To impose a stress treatment, we severed lateral roots and rhizomes of a native crucifer (bittercress, Cardamine cordifolia) and quantified plant and herbivore responses for treatment ...
متن کاملPredispersal reproductive ecology of an arid land crucifer, Moricandia moricandioides: effect of mammal herbivory on seed production
In this paper the effect of herbivory on the seed production of Moricandia moricandioides (Cruciferae), an annual species living in arid habitats of southeastern Spain, is analysed. Firstly, the flowering and fruiting phenology and the composition and structure of the pollinator guild is described, in order to compare the overall effect of mutualistic species vs. that of antagonistic species on...
متن کاملAllelopathic effects of different phenological stages of Cassia occidentalis L. on Parthenium hysterophorus L. Narsingh Bahadur Singh*, Sanjay Kumar, Deepti Singh and Kavita Yadav
The effect of leachates of different phenological stages of Cassia occidentalis L. on Parthenium hysterophorus L. was studied. Seed germination, radicle length, plumule length and fresh and dry weight of Parthenium were recorded. Pigments and protein contents were also measured to evaluate relation between biochemical and biophysical parameters of Parthenium under stress. The leaf leachate of C...
متن کامل