Spatially complex neighboring relationships among grassland plant species as an effective mechanism of defense against herbivory

• Published in: Oecologia Vol. 164; no. 1; pp. 193 - 200
• Main Authors: Wang, Ling, Wang, Deli, Bai, Yuguang, Huang, Yue, Fan, Meng, Liu, Jushan, Li, Yexing
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.09.2010; Springer; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Associational plant defense; Biological and medical sciences; Biomedical and Life Sciences; Coexistence; Community structure; Defense industry; Diet; Diet selection; Ecology; Ecosystem; Ecosystems; Feeding Behavior; Food consumption; Foraging; Foraging behavior; Fundamental and applied biological sciences. Psychology; General aspects; Grasses; Grasslands; Herbivores; Herbivory; Hydrology/Water Resources; Indigenous plants; Indigenous species; Life Sciences; Maintenance; Male; Neighborhoods; Palatability; Plant communities; Plant diversity; Plant Sciences; Plant species; PLANT-ANIMAL INTERACTIONS - ORIGINAL PAPER; Plants; Poaceae; probability; Risk reduction; Sheep; Social aspects; spatial distribution; Spatial scale; Species; Species diversity; vulnerability; Associational plant defense; Spatial distribution; Spatial scale; Diet selection; Foraging behavior; Feeding behavior; Herbivorous; Diet; Defense mechanism; Herbaceous plant; Plant defense; Feeding
• ISSN: 0029-8549; 1432-1939; 1432-1939
• DOI: 10.1007/s00442-010-1676-3

Close spatial relationships between plant species are often important for defense against herbivory. The associational plant defense may have important implications for plant community structure, species diversity, and species coexistence. An increasing number of studies have focused on associational plant defense against herbivory at the scale of the individual plant and its nearest neighbors. However, the average neighborhood effects between plant species at the scale of whole plant communities have received almost no attention. The aims of this study were to determine patterns of spatial relationship between different plant species that can provide effective defense against herbivory. We conducted a manipulative experiment using sheep and three native plant species with different palatability. Consumption of palatable plants by herbivores was largest when the three plant species were isolated in three patches and independent of each other. A homogenous and spatially equal neighbor relationship between the three species did not reduce the risk of herbivory of palatable species compared to isolation of these species, but it reduced the total intake of all plant species. The palatable species was subject to less herbivory in a complex spatial neighborhood of several plant species. High complexity of spatial neighborhood resulted in herbivores passively reducing selectivity, thereby reducing the probability of damage to palatable species in the community, or making inaccurate judgments in foraging selectivity between and within patches, thereby reducing the vulnerability of palatable plants and even the whole plant community. We conclude that compelling herbivores to passively reduce the magnitude of foraging selectivity by establishing spatially complex neighborhoods between plant species is a compromise and optimal spatial strategy by plants to defend themselves again herbivory. This may contribute not only to maintenance of plant species diversity but also to a stable coexistence between herbivores and plants in grassland ecosystems.