S. K. Ghildiyal

Effects of slope aspects on forest compositions, community structures and soil properties in natural temperate forests of Garhwal Himalaya

The present study was undertaken in seven natural forest types of temperate zone (1500 to 3100 m, a.s.l.) of Garhwal Himalaya to understand the effects of slope aspects viz., north-east (NE), north-west (NW), south-east (SE) and south-west (SW), on the forest structure, composition and soil characteristics of each selected forest type. The sample plots in each forest type were laid out by using stratified random approach. The indices i.e., the Importance Value Index, Shannon-Wiener diversity index, Simpson’s concentration of Dominance, Simpson diversity index, Pielou equitability and Margalef species richness index were calculated statistically using standard softwares to elucidate the differences in forest structure and composition of forest types on different slope aspects of the sites. The composite soil samples were taken from each forest stand and the physico-chemical properties of the soil i.e., moisture content (MC), water holding capacity (WHC), pH, organic carbon (OC), phosphorus (P), potassium (K) and available nitrogen (N) were analyzed. The results show that the higher values of total basal cover (74.4 m2·ha−1 in Quercus semecarpifolia forest), Concentration of dominance (0.85 in Pinus roxburghii forest) and Tree diversity (1.81 in Quercus floribunda forest) in the forests were recorded in the northern aspects. MC (40.8% in Quercus leucotrichophora forest), WHC (48.9% in Cupressus torulosa forest), OC (3.8% in Cedrus deodara forest), P (31.9 kg·ha−1 in Quercus leucotrichophora forest) and N (1.0% in Pinus roxburghii forest) had also higher values in the soils of northern aspects. Consequently the higher productivity of the forests was also noticed on the northern aspects.

Regeneration dynamics of dominant tree species along an altitudinal gradient in moist temperate valley slopes of the Garhwal Himalaya

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.

Annual variation in flowering phenology, pollination, mating system, and pollen yield in two natural populations of Schima wallichii (DC.) Korth.

Background. Schima wallichii is a highly valuable tree of tropical forest in north-east Himalaya region that grows naturally in a wide range of altitudes between 750 and 2400 m asl with varying environments. Flowering phenology of tropical tree species at population level is generally ignored and therefore a detailed knowledge of flowering and fruiting patterns of important multipurpose tree species is critical to the successful management of forest genetic resources. Materials and Methods. The study was conducted at two different altitudes (i.e., 750 m and 900 m asl) in the tropical semideciduous forest of north-east Himalaya. The floral phenology including flowering synchrony in the populations, anthesis, anther dehiscence, stigma receptivity, pollinators visitation frequency, and mating system including index of self-incompatibility were worked out in Schima wallichii according to the ear-marked standard methods given by various scientists for each parameter. Results. The flowering period in Schima wallichii varied from 33 to 42 days with mean synchrony of 0.54 to 0.68 between the populations. The stigma was receptive up to 2.5 days only and showed slightly protandrous type of dichogamy. Average pollen production ranged between 6.90 × 107 pollen per tree in 2007 and 15.49 × 108 pollen per tree in 2011. A three-year masting cycle was noticed in this species. The frequency of visitation of honey bees was fairly high (5.2 ± 1.12 visits/flower/hour) as compared to other pollinators. The hand pollination revealed maximum fruit (74.2 ± 5.72%) and seed (70.8 ± 7.46%) settings. Conclusions. The variation in flowering phenology and pollen yield individually and annually along with temporal separation in anther dehiscence and pollinators visitation cause pollen limited reproduction, which ultimately influences the reproductive success in Schima wallichii.

Tree species composition and diversity along an altitudinal gradient in moist tropical montane valley slopes of the Garhwal Himalaya, India

The study was conducted along an altitudinal gradient (1500 to 2850 m above sea level) in moist tropical montane valley slopes of the Mandal-Chopta area in the Garhwal region of India. Twelve forest types according to the altitude, slope aspect, and species compositions were selected for the study. The aims of the study were to describe and examine the structure and composition of the tree vegetation along an altitudinal gradient, and to compare the results of the present study with the other forests of Uttarakhand Himalaya growing at similar altitudinal range. High values of stem density and species diversity were recorded in mixed broad-leaved forest types growing between 1600 and 2400 m a.s.l., whereas forest types growing at higher altitudes (>2400 m a.s.l.) had low species richness and stem density. Tree density (tree ha−1) showed positive relationship with species richness and Shannon–Wiener diversity index. Forest types growing at higher altitude (>2400 m a.s.l.) showed geometric dominance-diversity curves. The values of stem density and total basal area in most of the forest types were higher than the earlier reported values from other parts of the Uttarakhand Himalaya.

Reproductive Ecology of Male and Female Strobili and Mating System in Two Different Populations of Pinus roxburghii

We studied several flowering traits, namely, male-female cone phenology, male-female cone production per tree, mating system, sex ratio, air-borne pollen grains and pollen migration, over four successive years in two different natural populations of P. roxburghii from Garhwal Himalaya, India. Assessment of each trait mentioned except pollen dispersion was done by selecting five representative trees randomly in each population. The pollen migration was studied on naturally isolated source trees. The pollen trapping was done in all directions up to 2.5 km. The average reproductive period in P. roxburghii was 36 days with 3–5 days protandry. There were significant year and population effects for male and female cone output and pollen grains production per tree. In mass production year (1999), an average production of pollen cone per tree was estimated as 42.44 ± 8.32 × 103 at lower altitude and 28.1 ± 0.89 × 103 at higher altitude. The controlled pollination results in high level of outcrossing with 90% seed setting. We conclude that the high male-female ratio and tremendous pollen production capacity in P. roxburghii indicate high male competition among trees within populations. The isolation strip of 600 m is considered minimal for the management of seed orchard.

Forest utilization pattern in relation to socio-economic status of people in Dudhatoli area of Garhwal Himalaya.

ABSTRACT Over the past few decades, the Himalaya has experienced unprecedented land use changes driven by rapid population growth and intensified human activities. Pressure on forests and their products has dramatically increased. Understanding forest products consumption is thus fundamental for assessing human-environment interactions and designing effective conservation policies in the Himalaya. This case-study focused on the relationship between the socio-economic status of the inhabitants, the forest utilization pattern and the anthropogenic pressures on the forest in the Dudhatoli area of Garhwal Himalaya, between 1750 m and 2200 m asl. Agricultural production and labour employment were the main occupation of the villagers in the study area. Approximately 82% (35,48 Quintals/annum/household) of total fuel wood and 78% (39,81 Quintals/annum/household) of the total consumed fodder was extracted from the forest, Dudhatoli forest is thus facing tremendous anthropogenic pressure. A total of 22 forest tree species were recorded to be used for a variety of purposes by the villagers. Anthropogenic pressure was highest in the forests close to the villages, and Quercus species were the most affected. Tree species richness and canopy cover was higher whereas stem density was lower in the undisturbed forests than in forests near the villages.

Effect of pre-soaking and pre-chilling treatments on seed germination of Pinus roxburghii provenances from western Himalaya, India

After subjecting the seeds to GA3, and H2O2 treatments for 24 h and chilling at 2–3°C for a period of 15 days, we conducted the seed germination tests for 21 different seed sources of Pinus roxburghii from western-central Himalaya under laboratory conditions at various temperatures viz., 20°C, 25°C and 30°C inside a seed germinator. The results reveal that the soaking of seeds in H2O2 (1% v/v) and GA3 (10 mg·L−1) solutions manifested 82.39% and 78.19% germination, respectively whereas untreated seeds exhibited 70.79% average germination. Both GA3 and H2O2 treatments caused an appreciable shortening of the germination period by 8 days and 10 days, respectively. Moist-chilling did improve the rate and percentage of germination when germinated at 20°C over 21 days; however total germination was not affected at temperatures 25°C and 30°C. Although the seeds of P. roxburghii germinate well due to lack of dormancy, the increasing demand for large quantities of seeds of P. roxburghii for reforestation programmes make pre-sowing treatments useful in improving the rate and percentage of germination.

Effect of temperature on cone bursting, seed extraction and germination in five provenances of Pinus roxburghii from Garhwal Himalaya in India

Pinus roxburghii (chir pine or long-needle pine) is considered to be a fire-hardy species. In this study the effect of a wide range of elevated temperatures (from 40 °C to 150 °C) on cone bursting and subsequent seed germination was examined in five provenances of P. roxburghii in comparison to sun drying. The maximum germination percentage (88.6 ± 1.46%; mean ± SE) was recorded with seeds from the Jasholi provenance extracted from cones dried artificially at 40 °C and germinated at 25 °C. At bursting these cones retained 6.9 ± 0.83% moisture content and the seeds retained 8.8 ± 0.32% moisture content. The germination percentage of the seeds from the Jasholi provenance extracted at 150 °C, at which temperature cone bursting occurred within 45 min, was only 22.2% when germinated at 30 °C. These cones retained 4.8 ± 0.54% moisture content and the seeds retained 7.0 ± 0.42% moisture content after bursting. In general, increasing temperature above 40 °C was inversely proportional to seed germinability.