The fine root (diameter ≤2.0 mm) biomass and morphology of Japanese red pines (Pinus densiflora) grown under different aboveground conditions (i.e., high and low competitive environments) were examined in a pine–cypress
mixed forest. All P. densiflora subject trees were about 40 years old, and the aboveground condition (i.e., size) of red pines appeared to be influenced
by the surrounding Japanese cypress (Chamaecyparis obtusa). Smaller P. densiflora exhibited lower fine root biomasses, shorter root lengths, and lower root tip densities, but longer specific root lengths
and higher specific root tip densities relative to larger pines. These results suggest that P. densiflora may adjust the morphological traits of fine roots to the different conditions in biomass allocation to fine roots of individuals
with different aboveground growth. 相似文献
Morphology and vertical distribution patterns of spruce and beech live fine roots (diameter ≤2 mm) were studied using a soil
core method in three comparable mature stands in the Solling: (1) pure beech, (2) pure spruce and (3) mixed spruce–beech.
This study was aimed at determining the effects of interspecific competition on fine root structure and spatial fine root
distribution of both species. A vertical stratification of beech and spruce fine root systems was found in the mixed stand
due to a shift in beech fine roots from upper to lower soil layers. Moreover, compared to pure beech, a significantly higher
specific root length (SRL, P<0.05) and specific surface area (SSA, P<0.05) were found for beech admixed with spruce (pure beech/mixed beech SRL 16.1–23.4 m g−1, SSA 286–367 cm2 g−1). Both indicate a flexible ‘foraging’ strategy of beech tending to increase soil exploitation and space sequestration efficiency
in soil layers less occupied by competitors. Spruce, in contrast, followed a more conservative strategy keeping the shallow
vertical rooting and the root morphology quite constant in both pure and mixed stands (pure spruce/mixed spruce SRL 9.6/7.7 m g−1, P>0.10; SSA 225/212 cm2 g−1, P>0.10). Symmetric competition belowground between mixed beech and spruce was observed since live fine roots of both species
were under-represented compared to pure stand. However, the higher space sequestration efficiency suggests a higher competitive
ability of beech belowground. 相似文献