Tree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests

Abstract

BackgroundPrevious studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition.Methodology/Principal FindingsWe assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N) concentration and lowest lignin∶N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin∶N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid mites did not.Conclusions/SignificanceAlthough some soil characteristics were unaffected by tree species identity, our results clearly demonstrate that these dominant tree species are associated with soils that differ in several physical, chemical, and biotic properties. Ongoing environmental changes in this region, e.g. changes in fire regime, frequency of insect outbreaks, changes in precipitation patterns and snowpack, and land-use change, may alter the relative abundance of these tree species over coming decades, which in turn will likely alter the soils.

Soil organic carbon stocks and CO2 effluxes of native and exotic pine plantations in subtropical China

“…Thus, both pine species were suitable for reforestation in terms of SOC storage management. This result is in agreement with that in several forests (Ehrenfeld, 2003;Ayres et al, 2009;Trum et al, 2011). The inconsistent effects of exotic tree species on SOC stocks may be explained by the inherent species-specific characteristics and the stand age.…”

“…In support of this concept, several exotic tree species, as compared with native species, changed SOC stocks (Chapela et al, 2001;Zinn et al, 2002;Ehrenfeld, 2003;Ladegaard-Pedersen et al, 2005;Russell et al, 2007). However, no significant differences in SOC storage between the native and exotic species were also documented (Ehrenfeld, 2003;Ayres et al, 2009;Ma et al, 2014). Therefore, it is an important but unresolved issue that how exotic tree species affect SOC storage as compared with the native ones.…”

Controls on Coarse Wood Decay in Temperate Tree Species: Birth of the LOGLIFE Experiment

“…Tree species composition determines the physical and chemical properties of forest soils and drives decomposer community composition and abundance (Strickland et al 2009;Ayres et al 2009). Forest composition, age distribution and structure also determine the light regime on the forest floor, with obvious consequences for temperature and moisture regimes ).…”

Dynamics of leaf litter humidity, depth and quantity: two restoration strategies failed to mimic ground microhabitat conditions of a low montane and premontane forest in Costa Rica.

“…Selection of a restoration strategy impacts micro and macro-scale elements, such as soil temperature, litter quality, soil respiration rates, nitrogen availability, microbial biomass, faunal community composition, among others, that would influence the functioning of the restored forest or ecosystem (Ayres et al 2009a). Therefore, technical analysis of restoration strategies require multi-disciplinary and ecosystem level studies.…”

“…One of the basic components of a tropical forest is the litter that accumulates on the ground, it constitutes an essential part of nutrient cycling (Wardle 2002, Álvarez-Sánchez & Harmon 2003, Ayres et al 2009a, CastellanosBarliza & León 2011. The vegetation that is chosen in a restoration program will define temperature and soil humidity, mainly due to canopy density, stratus structure, sunlight that can reach understory and soil, leaf litter production and decomposition rate, and tree falling rate, among others (Mosquera et al 2007).…”