Biomass, Productivity, Leaf Longevity, and Forest Structure in the Central Himalaya

Abstract

Patterns of leaf characteristics, forest structure, tree species diversity, biomass, and productivity across a gradient of 3300 m and 15.7°C in mean annual temperature in Kumaun, in the Indian central Himalaya, were summarized and compared to values from other similar forests. Throughout the elevational gradient, the annual rainfall was high (100—300 cm), but not correlated with elevation. Evergreen species with a 1—yr leaf life—span dominated most of the elevational transect; above 1800 m, species with deciduous and multiyear evergreen leaves were also well represented. Although variability among sites within forest types was high, a number of consistent patterns were apparent. Forests of Pinus roxburghii and those at high elevations were most consistently different from other forest types. Leaf life—span was not strongly correlated with leaf mass, specific leaf mass, or leaf production efficiency (net primary productivity per unit leaf mass), contrary to relationships presented in the literature. Tree species richness and basal area were lower than for most similar types in Nepal. Biomass and productivity of the forests in Kumaun were relatively high, compared to mean values for similar forest types elsewhere. Measured values for most variables describing these forests (but not all) fell within the ranges for the variables in similar forests worldwide. The maximal values for forest biomass remained high, 500—600 Mg/ha, up to 2600 m elevation, but declined sharply in birch forest (°170 Mg/ha) above 3100 m. Net primary productivity (NPP) varied little (15—20 Mg°ha—1°yr—1) below 2700 m, despite a 10°C gradient in mean annual temperature and marked changes in basal area, tree density, growth form, and leaf characters. The level of productivity appeared not to be limited by rainfall, forest structure, leaf type, or temperature above an annual mean of 11°C. Leaf mass (LM) varied considerably among forest types, being 3.7—8.6 Mg/ha for deciduous species, 5.7—8.9 Mg/ha for P. roxburghii, and 10.0—28.2 Mg/ha for evergreen broad—leaved species. Leaf mass duration (leaf mass x months of the year with leaves present) was related directly to NPP and inversely to leaf production efficiency (NPP/LM). These data add substantially to the data base for forest properties, especially for broad—leaved evergreen forests.

Resource Use Impacts Within the Forest Land Cover of Khangchendzonga Biosphere Reserve, Sikkim Himalaya Along Different Disturbance Levels and Altitudinal Zones

“…Species richness declined with altitude; its upper limit remained high up to 2600 m, and then declined sharply. This relationship is similar to that reported for Central Himalayan altitudinal transect by Singh et al (1994). Relationship drawn between species diversity and richness in disturbed, partially disturbed and undisturbed Chhetri et A good richness and diversity will describe the height of anthropogenic pressure on the species and this pressure varied from elevation to elevation which will be a good tool for management of biosphere reserve in future.…”

Regeneration dynamics, population structure, and forest composition in some ridge forests of the Western Himalaya, India

“…due to the younger growing stage (more individuals at lower DBH classes) at these altitudes. This recorded value is higher than the earlier reported values of 240 trees ha ¡1 by Ram et al (2004) from Kumaun Himalaya, 250-340 trees ha ¡1 by Baduni and Sharma (1999) and 366-466 trees ha ¡1 by Ghildiyal et al (1998) from Garhwal Himalaya for Q. floribunda forest, but lower than reported by Singh et al (1994) from Kumaun Himalaya. However, our values are similar to those reported by Bisht et al (2013) (620 trees ha ¡1 ).…”

Growth-form regulates the altitudinal variation of interspecific seed mass of woody plants in Mt. Dalaoling, the Three Gorges Region, China

“…键作用 (Salisbury, 1974;Leishman & Murray, 2001;Stevenson et al, 2005), 并对植物群落构建的环境筛 选过程与结果具有不可替代的影响 (Arssen, 2005;Díaz et al, 2016)。 海拔是山地植被分异的主导环境梯度 (Körner, 2007), 也是生物多样性宏观分布格局的重要调控 因素 (Rahbek, 1997;Körner, 2000 (Fielding et al, 1999;Walker et al, 2014)、年轮宽度 (Wang et al, 2005;Sidor et al, 2015)、叶片性状 (Singh et al, 1994;罗璐等, 2011;Jiang & Ma, 2015 Elevation, 物种海拔分布范围的中点; GF, 生长型, 包括乔木、小乔木、灌木和木质藤本; Leaf, 叶性状, 包括常绿阔叶、落叶阔叶和针叶。 Elevation, elevation of mid-point of altitudinal species range; GF, growth form, including tree, small tree, shrub and aliana; Leaf, leaf features, including evergreen broad-leaved, deciduous broad-leaved, and coniferous; d.f., degree of freedom. 发现植物种子质量随海拔上升而减小 (Baker, 1972;Bu et al, 2006;郭淑青, 2007;Guo et al, 2010;Dainese & Sitzia, 2013), 并认为能量是海拔梯度上 种间种子质量变化的主要限制因子 (Qi et al, 2015 Dainese M, Sitzia T (2013).…”