S. S. Bargali

Patterns of weight loss and nutrient release from decomposing leaf litter in an age series of eucalypt plantations

Abstract Decomposition of leaf litter in an age series (1–8 yr) of eucalypt plantations, raised after the clear-felling of natural mixed broad leaf forest, was studied using litter bags exposed in each plantation to examine the weight loss pattern and nutrient dynamics. Analysis of variance indicated significant differences in weight loss between age and time. The most rapid weight loss occurred in the 1 yr old plantation and decreased with plantation age. The decomposition rate was lower than in the surrounding natural mixed broad leaf forest and adjacent natural sal (Shorea robusta) forest. The rates of decomposition were significantly correlated with initial nutrient concentrations. Of the nutrients studied potassium was released most rapidly.

Changes in soil characteristics in eucalypt plantations replacing natural broad-leaved forests

Properties of the top 30 cm of soil under plantations of 1-yr to 8-yr old Eucalyptus (the hybrid E. tereticornis) and in adjacent natural mixed broad-leaved forest were compared in the sub-tropical zone of the central Himalaya. Various soil- physical characteristics decreased with increasing age; soil- chemical properties, notably organic carbon, total N, P and K decreased as a result of reforestation with Eucalyptus and further decreased with increasing age of the plantation.

Wildland fires and moist deciduous forests of Chhattisgarh, India: di- vergent component assessment

We studied moist deciduous forests of Chhattisgarh, India (1) to assess the effect of four levels of historic wildland fire frequency (high, medium, low, and no-fire) on regeneration of seedlings in fire affected areas during pre and post-fire seasons, (2) to evaluate vegetation structure and diversity by layer in the four fire frequency zones, (3) to evaluate the impact of fire frequency on the structure of economically important tree species of the region, and (4) to quantify fuel loads by fire frequency level. We classified fire-affected areas into high, medium, low, and no-fire frequency classes based on government records. Tree species were unevenly distributed across fire frequency categories. Shrub density was maximum in zones of high fire frequency and minimum in low-frequency and no-fire zones. Lower tree density after fires indicated that regeneration of seedlings was reduced by fire. The population structure in the high-frequency zone was comprised of seedlings of size class (A) and saplings of size class (B), represented by Diospyros melanoxylon, Dalbergia sissoo, Shorea robusta and Tectona grandis. Younger and older trees were more abundant for Tectona grandis and Dalbargia sissoo after fire, whereas intermediate-aged trees were more abundant prefire, indicating that the latter age-class was thinned by the catastrophic effect of fire. The major contributing components of fuel load included duff litter and small woody branches and twigs on the forest floor. Total fuel load on the forest floor ranged from 2.2 to 3.38 Mg/ha. The net change in fuel load was positive in high- and medium-frequency fire zones and negative under low- and no-fire zones. Repeated fires, however, slowly reduced stand stability. An ecological approach is needed for fire management to restore the no-fire spatial and temporal structure of moist deciduous forests, their species composition and fuel loads. The management approach should incorporate participatory forest management. Use of controlled fire, fire lines and mapping of fire prone areas are fundamental principles of fire hazard reduction in these areas.

Assessment of plant diversity, regeneration status, biomass and carbon stock in a Central Himalayan cypress forest

The present study assessed population structure, biomass, carbon stock, phytosociociological and regeneration status of a Central Himalayan cypress forest of India. A total of 36 plant species (07 trees, 08 shrubs and 21 herbs) were recorded from the study site. Total tree density ranged from 460 to 600 tree ha-1 and total basal area ranged from 19.11 to 58.20 m2 ha-1. The total biomass of trees across all the sites ranged between 178 and 431 t ha-1 while carbon stock ranged between 89.07 and 206 t ha-1. Cupressus torulosa was the only tree species showing fair regeneration at all the sites while most of the species were represented by seedling and sapling indicating new regeneration. Key words: Biomass, carbon stock, diversity, regeneration, vegetation structure.

Germination and Seedling Growth of Pulse Crop (Vigna Spp.) as Affected by Soil Salt Stress

Vigna is a genus of flowering plants in the legume family, Fabaceae with worldwide distribution. In the present study, effect of salt stress was investigated in four species of Vigna viz. V. mungo (urd), V. angularis (rais), V. radiata (moong) and V. aconitifolia (moth) at germination and seedling growth stages in a glasshouse experiment. Seeds of selected crops were surface sterilized and placed under three salt stress levels of 0 (control), 50 and 100 mM using NaCl solutions. Three replicates for each treatment was used for this experiment. The results indicated that increase in salt stress levels caused a reduction in germination percentage, germination rate, shoot length, root length and seedling dry weight of each Vigna species. The overall results indicated that among the four species, V. aconitifolia was the most sensitive, whereas V. mungo was the least sensitive species to the salinity in almost every aspect of growth. keywords: Germination percentage, Salinity, Seed vigour, Seedling growth, Sensitivity.

Agro-Biodiversity of Kumaun Himalaya, India: A Review

Kumaun Himalaya is one of the unique systems, rich in indigenous traditional knowledge and culturally strong. In the present study, qualitative and quantitative data were collected on agrobiodiversity through field and literature survey. Altogether, 161 plant species belonging to 117 genera and 57 families were recorded. In addition, a large number of land races, varieties and wild relatives are also being used. Cultivation of these crops is mainly of subsistence in nature rather than for commercial purposes. Due to a number of reasons, the area under traditional crops is declining in Kumaun Himalayan region but many of the crop varieties are still conserved because of their socio-cultural and religious values. The human population has increased over time forcing farmers to change their cropping patterns, for example, replacement of mixed cropping to mono-cropping and switching over to cash crops. This has adverse implications on traditional agro-biodiversity of the region. There are both local and global advantages in supporting a dynamic traditional system of agro-biodiversity management. Therefore, promotion and conservation of agro-biodiversity should be done through sustainable use and onfarm and offfarm management.

Bund Based Agroforestry Using Eucalyptus Species: A Review

Agroforestry system as an ecologically sustainable land use option alternative to the prevalent subsistence farming patterns for conservation and development. It is an old traditional practice but recently named as an agroforestry. A large hectare is available in the form of boundaries, bunds, wastelands where this system can be adopted. Eucalyptus is a cropland agroforestry tree species planted along with various annual crops like paddy, wheat, and cereals and other cash crops in farmers’ lands either in scattered or in bund. The main purpose of this review to provide/generates an idea about how Eucalyptus on bund behaves with associated crops i.e. interaction between both are studied in many aspects comprises outcome of yield, which is depends upon tree spacing, density, type and nature of existing bund plantation, their shading effects on morphology (internodes length, leaf area) and flower initiation/fruit-set of associated crops and their negative impacts on ecosystem includes competition of trees with crops for resources, allelopathic effects, rapid growth of trees occupy space of crops, etc. This review also includes carbon sequestration ability of Eucalyptus plantation with their growth and price trend behavior.

Possibilities and Perspectives of Agroforestry in Chhattisgarh

Agroforestry (AF) is an ecofriendly and sustainable modern farming land use practice that maintains overall farm productivity by combining herbaceous food crops with woody perennial trees and livestock on the same piece of land, either alternately or at the same time, using scientific management practices that improve the socioeconomic condition of people. It is the new name for an ancient land use practice and just a compromise between agriculture and forestry. It plays a major role in enhancement of overall farm productivity, soil enrichment through litter fall, maintaining environmental services such as climate change mitigation (carbon sequestration), phytoremediation, watershed protection and biodiversity conserva‐ tion. It is an effective and alternative management system to meet the target of increasing forest cover to 33 % as given by the national forest policy. Their scope and potential in any state including Chhattisgarh is tremendous. Farmers use generally N2-fixing trees like some from the Leguminosae family including Acacia spp., Dalbergia sissoo, etc., on their farmland for enhancing their field crops and generating incomes and employment. Therefore, rural people should make some strategy for the implementation of agroforestry model with suitable combination of trees and field crops, and this combination does not only generate income for the upliftment of socioeconomic value but also concerns the ecological and environmental stability on the sustained basis, i.e. emphasis should be more on scientific management of these models.

Effect of a Nitrogen-Fixing Actinorhizal Shrub on Herbaceous Vegetation in a Mixed Conifer Forest of Central Himalaya

In this study, we examined the effect of a nitrogen-fixing shrub Coriaria nepalensis Wall on herb species composition, diversity and biomass. The effect was measured in terms of species richness, diversity and biomass of herb species in three sites varying in Coriaria density viz. site 1 (low Coriaria density; 20 ind. ha-1), site-2 (medium Coriaria density; 120 ind. ha-1) and site-3 (high Coriaria density 190 ind. ha -1 ). Species richness was minimum at Site-1 (16 species), and maximum at site-2 (27 species). G. aparine dominated site-1 and Arthraxon sp dominated site-2 and 3. The individual herb density ranged between 0.40 - 42.40 m -2 , and total herb density ranged between 138- 170.4 m -2 and was maximum at site-2. Value for species richness (27) and Shannon Index (3.72) was highest for medium Coriaria density site and lowest for low Coriaria density site. Simpson Index ranged between 0.11 and 0.14 and was lowest for site-2 (medium Coriaria density) indicating that at this the dominance was shared by many species. Along the gradient of Coriaria density, maximum biomass was recorded at site-3 with highest Coriaria density and lowest at site-2 with medium Coriaria density. This may be due to the symbiotic nitrogen fixing ability of Coriaria that improve the habitat quality. The facilitative effect of C. nepalensis in terms of soil amelioration and herb growth can be used to regenerate degraded forest ecosystems.

Floral Composition and Diversity Pattern in Open and Closed Dry Deciduous Forest

Forests are the important source of subsistence, employment, revenue earning and raw material to various industrial uses. Above all they are most important component of life support system on the earth. The present study was conducted to analyze the impact of biotic disturbance on composition and diversity of dry deciduous forests of Barnawapara wild life sanctuary, Chhattisgarh, India. For this, two sites viz. open canopy forest and closed canopy forest were selected. Floristic analysis of tree vegetation was done and density, Important Value Index, diversity index etc. were determined for both the sites. Regeneration status of tree species was analysed by developing population structures. Species number was high in closed canopy forest as compared to open canopy forest. Tree density (1520 trees ha−1) and basal area (50.35 m2ha−1) were higher in closed canopy forest than in open canopy forest (650 trees ha−1 density and 48.29 m2ha−1 basal area). In sapling layer species number (14), density (590 saplings ha−1) and basal area (2.46 m2ha−1) were higher in closed canopy forest as compared to open canopy forest. Seedling layer also follow the similar trend. Generally, Shannon index, species richness and equitability were higher in closed canopy forest than open canopy forest. Thus, it can be concluded that biotic disturbance adversely affect the forest composition and diversity.