Overgrazed rangeland (200 mm annual rain)  has been planted with Pinus halepensis and Acacia saligna in 1983 as part of a “green belt” concept against desert encroachment. A first evaluation was carried out in 1996. The plantings survived because they were government plantations. The overall coverage was estimated at 50 to 65% Pinus reached a mean height of 3.8 m and a stem diameter (DBH) of  4.5 cm varying with slope position. The Acacia trees were smaller (2.6 m) but had a larger crown coverage (20 against 5.4 m2) and a thicker stem diameter. The planted and protected area had a denser ground cover than the area unprotected against grazing (64 against 13 g/m2). Weight contribution of different species is provided. An enrichment in C of the soil under the plantation was estimated but was not statistically significant. A positive effect of the plantation is seen in the protection and the consequently denser cover of the ground vegetation.

Teak (Tectona grandis L.f.) is a valuable commercial timber species which always faces a serious threat from leaf skeletonizer, Eutectona machaeralis and defoliator, Hyblaea puera. Selection of resistant teak clones on the basis of foliar defensive biochemicals is a very new approach of controlling this problem. In the studies carried out, 167 clones of teak belonging to ten states of India, introduced and planted during the years 1979-84 at National Teak Germ Plasm Bank, Chandrapur (Maharashtra) were considered as experimental host plants to evaluate resistant teak clones. In field, quantitative assessment of the severity of the damage was made by rating infested leaves visually on the basis of percentage of affected leaves individually in all four directions of all the clones. On the basis of visual observations, the clones were categorized into 9 groups, viz., most resistant, highly resistant, resistant, moderately resistant, least resistant, moderately susceptible, susceptible, highly susceptible and most susceptible. Some clones from each category were randomly selected for further confirmation of resistance against leaf skeletonizer and defoliator. In laboratory, feeding bioassay through no-choice and choice tests was carried out. Chemical screening of the contributory leaves of respective clones was also done. On the basis of data on leaf area consumed and foliar constituents, some resistant teak clones were identified. The inference drawn can be used as a screening criterion for selection of teak clones resistant to E. machaeralis and H. puera to large-scale plantation programmes.

Studies on survey and surveillance of insect fauna of important leguminous trees of Thar Desert was undertaken at Central Arid Zone Research Institute, Jodhpur. Study indicate major pests to be whitegrubs and termites in nursery, defoliators, shoot borers and sap suckers on established plants, bruchids on pods and seeds, and wood borer on old trees and felled timber. Gall making insects and their role in plant growth is also recorded in detail. The extent of damage and the status of the insect pest on leguminous trees have been discussed. Pollinators visiting flowers in different seasons and their abundance is recorded. Important parasites and predators which keep a natural check on pest incidence and practical management strategies for pest management are suggested.

Seedlings of Eucalyptus camaldulensis, Wrightia tinctoria and Bombax ceiba were inoculated with Azotobacter chroococcum and VAM fungi singly as well as in combination in root trainer under nursery conditions. All treated seedlings exhibited improved growth and biomass. But, better response was observed in both VAM-alone and VAM+Azotobacter treatment and least response was observed in Azotobacter-alone treatment. It can be concluded that microbial inoculation to tree species was found to improve productivity and this has to be practiced as integrated nursery management for quality seedling production and successful forest regeneration.

This paper describes the litter dynamics and nutrient use efficiency of high density Poplar (Populus deltoides) plantations in 1 to 4 yrs-old stand growing in Tarai belt adjacent to the Central Himalayan mountain, India. Tree density was 666 trees ha-1 in each plantation. In the forest floor biomass, the contribution of partially and more decomposed litter component was highest throughout the year.  The total litter fall was 2.38-5.69 t ha-1 yr-1 and increased with increase in as of stand. Of which, leaf, wood and root litter accounted for 80.6-83.6, 3.2 and 16.2 - 16.6%, respectively. However, the annual replacement of forest floor litters mass range from 93 (4-yr) to 96% (1-yr) with a turnover time 1.04 -1.07 year. The turnover rate of nutrients (NPK) was 0.83 to 0.92. It was decreased with increase in plantation age. The total amount of nutrient return to the soil through litter was 34 - 77 N, 4 - 9 P and 20 - 47 K kg ha-1 yr-1. It was increased with increase in plantation age because of higher litter accumulation. The nutrient use efficiency (NUE) ranged from 70 (1-yr) to 84 (4-yr) for N, 580 (1-yr) to 625 (4-yr) for P and 119 (3-yr) to 120 (4-yr) for K.

The present study revealed that the litter production in the shola forests of Nilgiri hills of Western Ghats is 2132 kg/ha/yr of which contribution of leaves was maximum. Nutrient concentration in the litter indicated that among components, highest concentration of N was found in leaves while P and K was maximum in reproductive parts and fruits respectively. Among different nutrients, N returned maximum while P the least. Among different litter components, leaves returned maximum amount of all the nutrients. Decomposition study indicated that 77 per cent of original leaf biomass was lost within one-year period. Slow initial mineralisation of N and rapid mineralisation of P and K is also evident from the decomposition study.

The population structure of the corridor forest was studied through density diameter relationships. The diameter distribution curves show that in most cases there is an equal representation of individuals in the inter mediate girth classes. In many cases the old trees with higher girth at breast height (gbh) values are seen to be exceptionally less thus leading to the preponderance of intermediate aged stands.  Shorea robusta, Anogeissus latifolius and, among the species under plantations, Tectona grandis and Dalbergia sissoo have very low seedling/sapling densities. Mallotus philippensis, which is actually an associate species of Shorea robusta, is gaining an increased dominance in almost all the communities and showed a good representation of individuals from the seedling level to mature trees in the corridor forests. Most of the old plantations, particularly those of Dalbergia sissoo had other species coming up thus indicating signs of natural regeneration and slow recovery towards mixed deciduous forest.

Green house investigation was conducted to study the interaction of Rhizobium and Glomus macrocarpum on Albizia lebbeck. Two efficient Rhizobium strains (R1 and R2) were used.  Glomus macrocarpum was applied to the soil @ 8.94 g/pot which contained 12,500 infective propagules. A total of six treatments were given using different combinations and the observations were recorded for over three months. The shoot height, shoot, root and nodule dry weight, the nitrogen and phosphorus contents of root and shoot were studied. Shoot length was found to be significantly higher in both dual inoculated treatments. The same trend was observed with respect to shoot, nodules and total dry weight. The shoot nitrogen content differed significantly but not root nitrogen content. The shoot P content was found to be maximum in VAM treatment followed by dual inoculations with R1. The root P content was found to be higher in VAM inoculated and dual inoculated treatments. It was highest in R2 plus VAM treatment.

Karyomorphological details have been investigated in the two species of the genus Salvadora - an important medicinal and multipurpose tree of Rajasthan. The somatic chromosome number in both the species S. persica and S. oleoides has been observed as 2n= 24, with distinct interspecific variation in the arm ratio of the twelve homologous pairs of chromosomes. Nucleolar chromosomes are reported in the S. persica (BSJO 19573) and the karyotypes in both the species were of symmetrical type. The role of karyotypic nature in speciation and evolution of the genus Salvadora has been discussed in detail.

Biological diversity and changes in chemical properties of soil under Gmelina arborea Roxb. and Anthocephalus cadamba (Roxb.) Miq. plantations raised on bhata wastelands of Raipur, Chhatisgarh (India) was studied in October, 1999. The number of ground flora species under Gmelina arborea and Anthocephalus cadamba was 33 m^-2 and 19 m^-2 respectively. On the basis of importance value index (IVI), Tridax procumbens L. and Desmodium triflorum (L.) DC. were the dominant herb under Gmelina arborea and Anthocephalus cadamba plantations respectively. In general, distribution of most of ground flora species was contiguous. Index of dominance was lower and index of diversity was higher for ground flora under plantations than that of open bhata land. The ground flora under Gmelina arborea has highest diversity index (4.251) than Anthocephalus cadamba (3.778) and open bhata land (3.219). The index of dissimilarity between plantations and open bhata land is high which indicates remarkable degree of dissimilarity in ground flora species.  However, there was plenty of similarity between two plantations as far as ground flora under them was concerned. The population of bacteria, fungi, nematodes, micro-arthropods and vesicular-arbuscular mycorrhizal (VAM) fungi spores were significantly more in soil under plantations than that of open bhata land. The soils under plantations have significantly high fertility status.

Studies on floral and reproductive biology of Rohida (Tecomella undulata (Sm.) Seem.) indicated onset of flowering in January, which continued up to second week of May. In bisexual flowers anthesis occurred normally in between 6 a.m. to 12 noon and dehiscence nearly an hour after anthesis. The sub-spheroidal pollen measuring 78.14 x 69.9 µ had 96% fertility. The pollen germination and the pollen tube length were maximum at 10% sucrose solution supplemented with 0.005% boric acid. The stigma remained receptive up to 24-30 hours of anthesis. The studies indicated entomophilous nature of flowers. The number of seeds/fruit varied according to the fruit length. There was dispersal of winged seeds on dehiscence of the mature fruits.

A germination study was conducted in College of Forestry, Kerala Agricultural University, Vellanikkara with an objective of finding out the most promising scarification (chemical) pretreatment for four selected tree species of farm/agroforestry importance. Treating the seeds with concentrated sulphuric acid for 5 minutes proved to be the best seed pretreatment in Prosopis cineraria, Paraserianthus falcataria and Leucaena leucocephala in terms of germination, while boiling water treatment for 5 minutes produced superior results in Ceiba pentandra.  Days taken for germination did not vary significantly due to various treatments.

The paper presents an enumeration of 112 species of macrolichens from Palakkad District of Kerala State, based on a field survey in order to assess the lichen diversity of the state.

Sexual behaviour including flowering process, anthesis, sorosis and seed formation was observed in six promising mulberry varieties namely Chinese White, Chak Majra, S146, Kanva-2 (Morus alba), Sujanpur and Mandalay (M. indica) under sub-tropical conditions. The time taken for complete opening of first buds ranged from one to five days. The varieties were either exclusively females (Kanva-2 and Sujanpur), monoecious (Chinese White, Chak Majra and S146) or predominantly monoecious with dioecious plants (Mandalay). The time taken for attaining maturity of female flowers within a variety ranged from a minimum of 4-5 days in Kanva-2 and Sujanpur to a maximum of 7-11 days in Chak Majra. The period of attaining maturity of male flowers ranged from 6-7 days in Mandalay (M. indica) to a maximum of 9-13 days in Chak Majra (M. alba). Receptivity period lasted to a maximum of 3-4 days and the dehiscence of anthers was complete within a period of 4-6 days. Pollen viability ranged from a minimum of 88.02% in Chak Majra (M. alba) to a maximum of 99.15% in Mandalay (M. indica). The sorosis maturation was complete within 43 days in Chak Majra (M. alba) to a period of 68 days in Mandalay (M. indica). The time taken for attaining complete colouration of the berries within a variety ranged from a minimum of 2-8 days in Chak Majra (M. alba) to a maximum of 23-25 days in Sujanpur (M. indica). The shape of the berry ranged from sub-globular in S146 and Sujanpur to cylindrical and elongated in Chinese White. The single sorosis weight ranged from a minimum of 1.055 g in Chinese White to a maximum of 1.750 g in S146. The number of achenes per berry (40.40) were more in S146 (M. alba) and less (29.20) in variety Mandalay (M. indica). Seed setting percentage ranged from a minimum of 9.53% in Chinese White (M. alba) to a maximum of 79.53% in Mandalay (M. indica). Varieties Sujanpur and Mandalay, representing M. indica produced heavier seeds. The seed viability ranged from a minimum of 58.00% in variety Mandalay (M. indica) to a maximum of 89.90 in variety S146 (M. alba).

Leaf extracts of four tree species and a shrub were screened in vitro for their fungitoxicity against the damping-off of fungi, viz., Fusarium oxysporum f.sp. dalbergiae and Rhizoctonia solani. Leaf extracts of Prosopis juliflora caused maximum inhibition of mycelial growth of both the fungal pathogens at all the dilution levels. It was followed by extracts from Eucalyptus tereticornis and Ocimum sanctum. The antifungal activity of all the tested plant extracts increased significantly with the increase in concentration, being the highest at 10 per cent concentration (maximum concentration tried).

Fair, reliable and comprehensive information on area and distribution of mangroves is the basic need for the mangrove resource management. The paper deals with the study conducted during 1997-98 to collect this vital information for Middle Andaman Forest Division. Result of the study shows mangrove area as 13006 hectares against the official figure of 23394.55 hectares.

Seeds of Grewia optiva were collected from four population of Himachal Pradesh. Seeds collected were sown in nursery. The leaves of the seedlings produced were analysed for DNA, RNA and amino acids for variation studies among four population. It was observed that maximum DNA content (72.02 mg/g) and RNA (211.2 mg/g) were present in leaves obtained from progeny of Kandaghat population whereas, amino acids content was highest (33.08 mg/g) in leaves obtained from progeny of Palampur population.