No abstract

The present study was undertaken in seven major forest types of temperate zone (1500 m a.s.l. to 3100 m a.s.l.) of Garhwal Himalaya to understand the effect of slope aspects on carbon (C) density and make recommendations for forest management based on priorities for C conservation/sequestration. We assessed soil organic carbon (SOC) density, tree density, biomass and soil organic carbon (SOC) on four aspects, viz. north/east (NE), north/west (NW), south-east (SE) and south-west (SW), in forest stands dominated by Abies pindrow, Cedrus deodara, Pinus roxburghii, Cupressus torulosa, Quercus floribunda, Quercus semecarpifolia and Quercus leucotrichophora. TCD ranged between 77.3 CMg ha⁻¹ on SE aspect (Quercus leucotrichophora forest) and 291.6 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). SOC varied between 40.3 CMg ha⁻¹ on SW aspect (Himalayan Pinus roxburghii forest) and 177.5 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). Total C density (SOC+TCD) ranged between 118.1 CMg ha⁻¹ on SW aspect (Himalayan Pinus roxburghii forest) and 469.1 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). SOC and TCD were significantly higher on northern aspects as compared with southern aspects. It is recommended that for C sequestration, the plantation silviculture be exercised on northern aspects, and for C conservation purposes, mature forest stands growing on northern aspects be given priority.

The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to assess the chemical properties of soils in relation to the forest structure and composition. Twelve forest types according to the altitude, slope aspect, and species composition were selected for the study. Chemical properties of the soil, i.e., total nitrogen (N), available phosphorus (P), available potassium (K), organic carbon (C), soil organic matter (SOM), pH and C:N ratios were analyzed for three different depths viz., (i) 'Upper' (0-10 cm), (ii) 'Middle' (11-30 cm), and (iii) 'Lower' (31-60 cm) in all the selected forest types. Phytosociological and diversity parameters viz. total basal cover (Gha -1 ), stem density (Nha -1 ), tree species richness (SR), Simpson concentration of dominance and Shannon-Wiener diversity index (H) were also calculated for each forest type.

The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to understand the regeneration dynamics of the dominant tree species along an altitudinal gradient in naturally regenerating, restricted access forest. The overall regeneration status was fairly high in the study area. Most of the native canopy and undercanopy dominants had frequent reproduction and expanding populations, which suggests the stability of forest structure/composition and further expansion of dominant species. The overall regeneration of trees in the forest had a greater contribution of middle and understorey species. Because of infrequent reproduction and declining populations of some of the dominant native species viz., Abies pindrow, Alnus nepalensis and Betula alnoides, structural/compositional changes in the future are expected in respective forests dominated by them. Abies pindrow and Taxus baccata need immediate attention by forest managers for their survival in the area. Seedlings were found to be more prone to competition from herb and shrubs than saplings.

The available data on climate change over the past century indicate that the Earth is warming. Important biological events, including changes in plant phenology, have been reported in many parts of the world. We have explored some of these phenological changes in more than 650 temperate species, which have indicated the average advancement of 1.9 days per decade in spring events and average delay of 1.4 days per decade in autumnal events. Thus the average length of the growing season has extended by 3.3 days per decade.