Microhabitat associations of lichens, feathermosses, and vascular plants in a caribou winter range, and their implications for understory development
Haughian, S. R. and P. Burton . 2015. Botany
Abstract
Vegetation-environment relationships are well understood for boreal lichen woodlands, but the mechanistic basis for small-scale understory patchiness (patches dominated by lichen, mosses, and vascular plants), and its implications for the prevalence of niche vs. neutral processes driving understory development, have not been explored. We asked whether predictable vegetation-environment associations exist at the microsite scale, with the goal of informing caribou range management. We sampled canopy and edaphic variables in patches of lichen, feathermoss, and vascular plants in subalpine lodgepole pine (Pinus contorta var. latifolia) forests, in north-central British Columbia, Canada. Lichens positively associate with microsites that have high light and heat, and low moisture and nutrient availability; vascular plants positively associate with base-cation availability, sulphur and phosphorus availability, fine-textured soils, thick organic layers, and high light; feathermosses positively associate with low light and heat, and nitrogen availability. Understory composition is most strongly associated with canopy characteristics, but is also related to edaphic properties in predictable ways; soil and canopy attributes may further interact to define distinct intra-stand niches. The viability of caribou winter ranges can likely be extended by partially thinning or burning the canopy and organic layers, but the longevity of a lichen-dominant stage may ultimately depend on the soil texture, due to its influence on vascular plant growth.
Key Words
canopy, feathermoss, Cladonia, microhabitat, understory
