Litterfall and soil characteristics in canopy gaps occupied by vine maple in a coastal western hemlock forest

Abstract

. 1997. Litterfall and soil characteristics in canopy gaps occupied by vine maple in a coastal western hemlock forest. Can. J. Soil Sci. 77: 703-711-000. In some low-elevation coastal British Columbia forests, canopy gaps can be occupied by the hardwood tree species, vine maple (Acer circinatum). The objective of this study was to determine how vine maple gaps influence litterfall, litter decomposition, and forest floor and mineral soil properties. Measurements were made on six vine maple gaps paired with six conifer canopy plots. Vine maple gaps had significantly less conifer litterfall during the autumn, higher pH, and higher concentrations of Ca, Mg and K in the forest floor, thinner forest floors, and a weak tendency for lower C/N ratios, higher pH values and higher total N concentrations in the surface mineral soil. Vine maple litter was found to decompose significantly faster than conifer litter and to have higher concentrations of N, P, Ca, Mg, K, Fe and Zn. Decomposition rates of vine maple litter and of conifer litter did not differ significantly between vine maple gap and conifer canopy plots. Larger vine maple clones had significantly thicker forest floors with higher concentrations of Ca, and higher N concentrations and lower C/N ratios in the surface mineral soil than gaps with smaller vine maple clones. The results indicate that vine maple gaps may improve the nutritional status of the sites that they occupy within conifer forests.Key words: Litterfall, litter decomposition, soil-plant interactions, vine maple, canopy openings, canopy gaps Ogden, A. E. et Schmidt, M. G. 1997. Caractères de la litière fraiche et du sol dans les trouées d'une forêt côtière à pruche de l'Ouest ovvupées par l'érable circiné. Can. J. Soil Sci. 77: 703-711. Dans certaines forêts côtières de basse altitude de la Colombie-Britannique, les clairières peuvent être occupées par l'érable circiné (Acer circinatum). Nous avons cherché à déter-miner dans quelle mesure ces clairières à érable circiné influent sur les dépôts et sur la décomposition de la litière ainsi que sur les propriétés des couches organiques et minérales du sol forestier. Des mesures en paires étaient prises dans 6 clairières à érable circiné jumelées à 6 placettes sous couvert de conifères. Dans les clairières, la litière nouvelle contenait significativement moins d'aiguilles de conifères en automne. La couche organique était plus mince, son pH plus élevé et elle contenait plus de Ca, de Mg et de K. Les horizons minéraux supérieurs affichaient des rapports C/N plus bas, un pH plus élevé et des concentrations en N total plus fortes. La litière d'érable circiné se décomposait significativement plus vite que la litière de conifères et elle était plus riche en N, P, Ca, Mg, K, Fe et Zn. Les taux de décomposition des deux types de litière n'étaient pas statistiquement différents selon qu'il s'agissait d'une placette de clairière ou d'une placette sous pruche de l'Ouest. La couche organique du sol était plus épaisse et plus riche en Ca et la couche minérale plus ri...

The influence of understory vine maple on forest floor and mineral soil properties in coastal temperate forests

“…Although most studies have looked at the role of vine maple as a competitor for resources with commercial trees (Haeussler et al 1990), recent research suggests that vine maple may improve site conditions to the benefit of surrounding Douglas-firs despite its relatively small stature (Ogden and Schmidt 1997). Vine maple was found to have significantly higher (P < 0.1) pH in the upper mineral soil, and significantly greater concentrations of Ca, Mg, and K in the forest floor relative to sites dominated by conifers (Ogden and Schmidt 1997). The study by Ogden and Schmidt (1997) was carried out in an 80-yr-old stand of western hemlock [Tsuga heterophylla) (Raf.)…”

“…Vine maple was found to have significantly higher (P < 0.1) pH in the upper mineral soil, and significantly greater concentrations of Ca, Mg, and K in the forest floor relative to sites dominated by conifers (Ogden and Schmidt 1997). The study by Ogden and Schmidt (1997) was carried out in an 80-yr-old stand of western hemlock [Tsuga heterophylla) (Raf.) Sarg.]…”

“…Wardman and Schmidt (1998) reported a significantly greater site index for Douglas-firs adjacent to vine maple (42.6 m) relative to Douglas-firs located in conifer-dominated areas (40.1 m). Wardman and Schmidt (1998) carried out their study in a 75-yr-old Douglas-fir-dominated stand adjacent to the stand studied by Ogden and Schmidt (1997). The greater site index may be attributed to improved nutrient availability on sites occupied by vine maple as greater N and B concentrations were found in the current-year foliage of Douglas-fir adjacent to vine maple relative to the surrounding conifer forest (Tashe and Schmidt 2001).…”

“…The retention of nutrients within ecosystems generally depends on the soil and vegetation (Pastor and Bockheim 1984). Research conducted by Pastor and Bockheim (1984) showed that understory sugar maple (A. saccharum Marsh.)…”

“…Research conducted by Pastor and Bockheim (1984) showed that understory sugar maple (A. saccharum Marsh.) may be important as a secondary sink for nutrients because of its ability to cycle nutrients under low light conditions.…”