Plant-environment relationships on the Montlake wildlife area, Seattle, Washington, USA

Abstract

Grassland vegetation on the Montlake fill was analyzed using TWINSPAN. Eight herb communities were recognized. Moisture, proximity to gas vents, and disturbance are the main factors that control species and community distributions. Binary discriminant analysis (BDA) and detrended correspondence analysis (DCA) were used to study species-environment relationships. BDA revealed complex species response patterns and the resultant indicator values were used to interpret the ordination axes. Species distributions are controlled primarily by moisture, but also influenced by soil pH. Multiple regressions revealed little about plantenvironment relationships not discovered by BDA. Before robust nonlinear methods are available, BDA, metric ordination with data stratification and nonmetric ordination are methods that can yield satisfactory results in exploratory plant-environment studies. BDA alone is an efficient, useful first approach where response patterns of species are initially unknown.

Characteristics of vegetation succession on the Pinus thunbergii forests in warm temperate regions, Jeju Island, South Korea

“…At level 2, the amount of information for some species was 0.2300 as an eigenvalue, and these species were divided into group I and group II by the indicator species Eurya japonica (+) and Neolitsea sericea (+); the amount of information for the remaining species was 0.3211 as an eigenvalue, and these species were divided into group III and group IV by the indicator species Litsea japonica (−) and Neolitsea sericea (+). The group classification by TWINSPAN was reported to be made with environmental factors such as the presence of specific species, altitudes above sea level, and soil humidity (Taylor et al 1987;Huang and Moral 1988;Lee et al 1990a;Lee et al 1990b;Lee et al 1991;Lee et al 1992), aspects (Lee et al 1990b), and forest fires (Allen and Partridage 1988). However, since the Pinus thunbergii forests surveyed in this study were limited to those at altitudes lower than 500 m above sea level and the growth environments of the constituent tree species were similar such as areas adjacent to the coast and alluvial lands where the water environment was relatively stable (Fuziwara 1981;Oh and Kim 1996;Choi 2012), the tendency of group separation by certain environmental factors was not clear.…”

Defining phytoclimatic units in Galicia, Spain, by means of multivariate methods

“…Indicator values of the 'pseudo-species' were taken from Retuerto (1989) who used frequential analysis to characterize the climatic behaviour of woody plants with respect to 92 climatic variables. 'Pseudospecies' selection is in accordance with Strahler (1978) and Huang & del Moral (1988). All taxa (including some subspecies and developmental stages) considered for subsequent analysis are listed in Table 1.…”