Premium
Assessment of the effects of environmental change on the performance and density of Bistorta vivipara : the use of multivariate analysis and experimental manipulation
Author(s) -
Totland Ø.,
Nyléhn J.
Publication year - 1998
Publication title -
journal of ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.452
H-Index - 181
eISSN - 1365-2745
pISSN - 0022-0477
DOI - 10.1046/j.1365-2745.1998.00318.x
Subject(s) - altitude (triangle) , population density , transect , biology , ectotherm , population , ecology , mathematics , demography , geometry , sociology
1 Studies of plant performance in relation to local variability in environmental conditions can be used to predict the responses of species to environmental change. 2 We used redundancy analysis to study how interpopulation variation in average plant weight, flower and bulbil number, bulbil weight and population density among 28 populations of Bistorta vivipara was related to variation in 15 environmental factors. We also examined the responses of plants to a 4‐year experimental increase in temperature. 3 Significant differences in average plant performance were found between populations. Variance partitioning of the response data showed that environmental factors explained 45% of the variation in plant performance and density between populations, whereas variation due to transect position was small (10.8%). Soil pH, altitude and season length were the most influential of the environmental variables, and explained 23%, 21% and 14%, respectively, of the variation. Plant performance was in general negatively correlated with these variables, whereas plant density increased along the pH and altitude gradients, suggesting that environmental factors associated with elevation (temperature and vegetation cover) and pH (soil fertility) had opposing effects on individual performance and density. Season length was highly important for average bulbil weight. 4 Plants growing in open top chambers had significantly enhanced growth and produced significantly heavier bulbils than those in control plots, whereas flower and bulbil number were unaffected by experimentally increased temperatures. Plant density was equal for warmed and control plots. 5 Although warming may increase bulbil weight and plant size in B. vivipara , the response to climate change is complicated by the fact that population densities may decrease due to intensified competition for light caused by a denser vegetation cover.