Total Basal Cover Research Articles

Fuelwood consumption of dhabas (temporary hotels) along an altitudinal gradient in a pilgrim and tourist affected protected area of western Himalaya

ABSTRACTThe present study was carried out in a remote area of the Indian Himalayas to assess the biomass use patterns of dhabas (temporary hotels) along an altitudinal gradient in a pilgrimage and tourism affected protected area. The dhaba owners extensively collect fuelwood for various purposes such as cooking, boiling water, and space heating. The study examined factors affecting and resulting from fuelwood usage and collection—including preferred species, gathering patterns, emissions of green house gases due to combustion, and ecological parameters such as density and total basal cover. Open- and close-ended questionnaires were used for interviews with the study subjects. Firewood was reported as the only available energy source in the area. The average fuelwood consumption at three altitudinal sites was 19 kg dhaba−1 day−1 at Site I (1,500–2,000 m asl), 26.62 kg dhaba−1 day−1 at Site II (2,000–2,500 m asl), and 16.74 kg dhaba−1 day−1 at Site III (2,500–3,600 m asl). The five most preferred species for firewood reported by the respondents were: Alnus nepalensis, Lyonia ovalifolia, Quercus floribunda, Pinus roxburghii, and Rhododendron arboreum. The present findings could be used as a baseline for developing various conservation and sustainability measures for protected areas influenced by human populations.

Variation in vegetation composition, biomass production, and carbon storage in ridge top forests of high mountains of Garhwal Himalaya

The present study was aimed to anticipate how forest composition, regeneration, biomass production, and carbon storage vary in the ridge top forests of the high mountains of Garhwal Himalaya. For this purpose five major forest types—(a) Pinus wallichiana, (b) Quercus semecarpifolia, (c) Cedrus deodara, (d) Abies spectabilis, and (e) Betula utilis mixed forests—were selected on different ridge tops in the Bhagirathi Catchment Area of the Uttarkashi District of Garhwal Himalaya. The highest species richness (10 species) and stand density (804 ± 184.5 stems ha−1) were recorded in Abies spectabilis forests, whereas lowest species richness (4 species) and species density (428 ± 144.7 stems ha−1) were found in Quercus semecarpifolia forests. The total basal cover (TBC) values were maximum (91.1 ± 24.4 m2 ha−1) in Cedrus deodara forests and minimum (26.5 ± 11.7 m2 ha−1) in Pinus wallichiana forests. The highest total biomass density (TBD) (464.2 ± 152.5 Mg ha−1) and total carbon density (TCD; 208.9 ± 68.6 Mg C ha−1) values were recorded for Cedrus deodara forests; however, lowest TBD (283.4 ± 74.8 Mg ha−1) and TCD (127.5 ± 33.7 Mg C ha−1) values for Quercus semecarpifolia forests. Our study suggests that Abies spectabilis-dominated forests should be encouraged for biodiversity enrichment and reducing carbon emissions on ridge top forests of high mountains.

Phytosociological Analysis of Woody Species in Kedarnath Wildlife Sanctuary and Its Adjoining Areas in Western Himalaya, India

Abstract The aim of the present study was to assess the variation in species composition and diversity of woody species at different altitudes (900 to 2600 m asl) in Kedarnath Wildlife Sanctuary (KWLS) and its adjoining areas in Garhwal Himalaya, India. A total of 94 woody plant species (including 44 tree and 50 shrub species) belonging to 72 genera and 44 families were reported. Density varied from 235±9 to 505±21 trees ha −1 and 4,730±474 to 9,530±700 shrubs ha −1 . Total basal cover varied from 10.49±0.66 to 42.92±2.57 m 2 ha −1 (trees) and 0.36±0.024 to 0.62±0.047 m 2 ha −1 (shrubs). Shannon-Wiener Index fluctuated between 2.30 to 3.53 (trees) and 2.74 to 3.78 (shrubs). Analysis of variance (ANOVA) indicated that altitude and aspect had significant effect on the distribution of woody species. Taxonomically, Rosaceae with 15 species emerged as the dominant family. Low value of maturity index and contiguous distribution of species denoted the early successional status of the studied forests. The conservation assessment based on altitudinal regimes and the information on species structure and function can provide baseline information for monitoring and sustaining the biodiversity.Key Words: Himalaya, Altitude, Vegetation, Diversity, Woody species

Long-term Protection from Heavy Livestock Grazing Affects Ponderosa Pine Understory Composition and Functional Traits

Making accurate predictions of plant community responses to grazing management is a major objective of rangeland ecology. Metrics such as species composition are site specific, whereas others such as functional groups and functional traits can be generalized across different rangeland types. We analyzed long-term (1912–1941) shifts in the understory community at five sites in a ponderosa pine (Pinus ponderosa P. & C. Lawson var. scopulorum Engelm.) forest when protected from heavy livestock grazing. We examined differences in total basal cover, species composition, species richness, functional group composition, and community-weighted mean (CWM) functional traits between heavily grazed and ungrazed areas in four time periods (1912, 1920, 1930, 1940). Total understory basal cover was greater in ungrazed than heavily grazed areas in 1920 but not in later time periods. Understory species composition diverged by 1930 and continued to differ in 1940. Functional group composition differed from 1920 onwards. In 1920 and 1930, C3 graminoids declined more in relative abundance in heavily grazed than ungrazed areas. By 1940, forbs accounted for much more of the cover in heavily grazed than ungrazed areas. During the study period, CWM specific leaf area and foliar Nmass declined by 8% and 11%, respectively, in ungrazed quadrats, while CWM leaf dry matter content increased 8%. Leaf traits, but not maximum height or seed mass, demonstrated consistent and predictable responses to protection from heavy grazing. Herbaceous understory species with leaf traits that allow for slower resource acquisition became more abundant in response to protection from heavy grazing. Our results indicate that managers should expect to observe more rapid changes in functional group composition and leaf functional traits than in species composition and species richness following protection from heavy livestock grazing.

Community Structure and Plant Diversity of Community Based Religious Conserved Forests of Garhwal Himalaya, India

The present study was carried out in four community based religious conserved forests areas i.e., Ansuiya Devi, Ulkagari, Maroor and Jameshwar in Garhwal Himalaya. The aim of the study was to access the ecological and diversity status. The selected sites have status either of reserve forest, communal forest/Van Panchyat or a combination of these apart from having several temples of religious significance. Study was conducted following the stratified random sampling technique by placing random quadrats of 10 m × 10 m size at forest floor. A total of 240 species of plants were recorded from the four study sites, which varied from 93 in Jameshwar to 119 in Ansuiya Devi. The density of these forests ranged from lowest of 782 trees/ha in Jameshwar to 1352 trees/ha in Maroor. The total basal cover (TBC) for trees showed a range of 31.67 m2/ha in Ulkagari to 84.34 m2/ha in Ansuiya Devi. Distribution pattern of whole herb and shrub layers were found contagious whereas only three tree species were found randomly distributed. Shannon diversity index (Hʹ) for tree species was recorded highest in Ansuiya Devi (2.93) whereas; lowest value (2.10) was recorded in Maroor. Species richness (Margalef index) for trees ranged from 3.29 to 4.35. The study is a pioneer in the aspect and can be helpful in making protocols and policy implications to protect these sites by involving local communities in biodiversity conservation outside the protected area network.

Integrated analysis of the trees and associated under-canopy species in a subalpine forest of western Himalaya, Uttarakhand, India

Subalpine forests are known as outstanding habitats due to co-existence of both temperate and alpine vegetation and are classic example of ecotonal zones. Limited but diverse physiognomy of trees inhabiting in subalpine forest results in variability within under-canopy habitat conditions. Studies were undertaken to assess population status, habitat preference and interferences to the trees and associated under-canopy herbs in a subalpine forest of western Himalaya. A total of 10 woody and 23 under-canopy herbs were recorded in the selected subalpine forest area. At each stand, the number of tree species and under-canopy herbs ranged from 2 to 4 and 8 to 10 respectively. Abies spectabilis, Acer caesium, Quercus floribunda, Q. semecarpifolia and Rhododendron arboreum were key tree species in this area. The density of main woody species was 280 to 1190 individuals ha-1 at different stands. Herbaceous plants with rosette and clump growth habits were observed to have higher values for total basal cover and importance value index. Presence of some under-canopy herbs like; Dactylorhiza hatagirea, Malaxis muscifera, Picrorhiza kurrooa, Polygonatum cirrhifolium and Skimmia laureola in the specific habitats also showed that they are habitat specific. However, the presence of Frageria nubicola and Viola sp. was common in the selected stands. Felling of trees for timber, construction of temporary huts, fuel wood and lopping for fodder were main interferences for trees. On the other hand, trampling driven damage due to grazing, habitats degradation and overexploitation were observed key threats for under-canopy herbs. Integrated analysis including population studies, habitats preference and interferences to the trees and under-canopy herbs in this sensitive and important ecosystem will be useful for determining the conservation plans and ecosystem management.

Altitudinal Variation in Species Composition and Soil Properties of Banj Oak and Chir Pine Dominated Forests

The study was carried out in two different forest types viz., Banj oak and Chir pine forests to assess the variation in forest species composition and soil properties along altitudinal gradients in the Garhwal Himalayas. The results of the study showed that between the forests soil moisture was higher in Banj oak forest because of closed canopy and dense forest compared to Chir pine forest. The sand particles were reported higher in Banj oak forest which might be due to the addition of organic matter favouring coarse structure of soil, helping in holding maximum water in soils. However in the Chir pine forest low amount of soil organic matter and presence of clayey soil, develops soil compactness which reduces the penetration of water resulting in high soil bulk density. The higher accumulation of litter and presence of moisture in Banj oak forest favours higher nutrient level of nitrogen, phosphorus and potassium compared to Chir pine forest. The soil organic carbon also reduced with increasing altitude at both gradients. While bulk density has reverse trend with soil organic carbon in both the forests at different peaks of same region. In Banj oak forest, the highest density and total basal cover was reported 1,100 tree <TEX>$ha^{-1}$</TEX> and 58.86 <TEX>$m^2\;ha^{-1}$</TEX> respectively. However, the highest values of density and total basal cover of Chir pine forest was 560 tree<TEX>$ha^{-1}$</TEX> and 56.94 <TEX>$m^2\;ha^{-1}$</TEX> respectively. The total density and basal cover of both the forests reduced with increasing altitude. The study concludes that Banj oak forest has better nutrient cycling ability, well developed foest floor and has a greater protective and productive features compared to the Chir pine forest which is without lower vegetation cover and having only pine litter accumulation which does not allow any other species to grow.

Chemical properties of soils in relation to forest composition in moist temperate valley slopes of Garhwal Himalaya, India

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 ( $$ \overline{\rm H} $$ ) were also calculated for each forest type. Values of N, P, K, C, SOM, C:N ratio and pH ranged from 0.17 to 0.45 %, 2.73 to 20.17 ppm, 40.67 to 261.17 ppm, 2.29 to 4.31 %, 3.95 to 7.43 %, 8.12 to 14.49 and 5.47 to 6.67, respectively. N showed a positive relationship with C and K. P was positively correlated with C and negatively correlated with altitude. P was higher in the soil of lower horizons of all the forest types. K was found to be positively correlated with altitude, C and N. pH of all the forest types was slightly acidic. C was comparatively higher in mixed broad-leaved forest types. No relationship between altitude and C was observed, which may be due to different composition of forest types along the altitudinal gradient and their differential decomposition rates. C content decreased with the depth of the soil. C showed positive correlation with N, P, and K. N showed a positive correlation with Gha−1. K showed a negative correlation with SR and $$ \overline{\rm H} $$ . P showed no relationship with the phytosociological parameters. This study also provides the comparisons between the results of chemical analysis of the present study with numerous other previous studies in the temperate Himalayan region of the Uttarakhand. The values of soil chemical properties of the present study in most of the forest types are on the higher end than the values previously recorded for the other similar forests of the region. The possible reason being luxuriant vegetation and undisturbed nature of these forest types, which is evident from higher values of diversity and other phytosociological parameters.

Ethnomedicinal and ecological status of plants in Garhwal Himalaya, India

BackgroundThe northern part of India harbours a great diversity of medicinal plants due to its distinct geography and ecological marginal conditions. The traditional medical systems of northern India are part of a time tested culture and honored still by people today. These traditional systems have been curing complex disease for more than 3,000 years. With rapidly growing demand for these medicinal plants, most of the plant populations have been depleted, indicating a lack of ecological knowledge among communities using the plants. Thus, an attempt was made in this study to focus on the ecological status of ethnomedicinal plants, to determine their availability in the growing sites, and to inform the communities about the sustainable exploitation of medicinal plants in the wild.MethodsThe ecological information regarding ethnomedicinal plants was collected in three different climatic regions (tropical, sub-tropical and temperate) for species composition in different forest layers. The ecological information was assessed using the quadrate sampling method. A total of 25 quadrats, 10 × 10 m were laid out at random in order to sample trees and shrubs, and 40 quadrats of 1 × 1 m for herbaceous plants. In each climatic region, three vegetation sites were selected for ecological information; the mean values of density, basal cover, and the importance value index from all sites of each region were used to interpret the final data. Ethnomedicinal uses were collected from informants of adjacent villages. About 10% of inhabitants (older, experienced men and women) were interviewed about their use of medicinal plants. A consensus analysis of medicinal plant use between the different populations was conducted.ResultsAcross the different climatic regions a total of 57 species of plants were reported: 14 tree species, 10 shrub species, and 33 herb species. In the tropical and sub-tropical regions, Acacia catechu was the dominant tree while Ougeinia oojeinensis in the tropical region and Terminalia belerica in the sub-tropical region were least dominant reported. In the temperate region, Quercus leucotrichophora was the dominant tree and Pyrus pashia the least dominant tree. A total of 10 shrubs were recorded in all three regions: Adhatoda vasica was common species in the tropical and sub-tropical regions however, Rhus parviflora was common species in the sub-tropical and temperate regions. Among the 33 herbs, Sida cordifolia was dominant in the tropical and sub-tropical regions, while Barleria prionitis the least dominant in tropical and Phyllanthus amarus in the sub-tropical region. In temperate region, Vernonia anthelmintica was dominant and Imperata cylindrica least dominant. The consensus survey indicated that the inhabitants have a high level of agreement regarding the usages of single plant. The index value was high (1.0) for warts, vomiting, carminative, pain, boils and antiseptic uses, and lowest index value (0.33) was found for bronchitis.ConclusionThe medicinal plants treated various ailments. These included diarrhea, dysentery, bronchitis, menstrual disorders, gonorrhea, pulmonary affections, migraines, leprosy. The ecological studies showed that the tree density and total basal cover increased from the tropical region to sub-tropical and temperate regions. The species composition changed with climatic conditions. Among the localities used for data collection in each climatic region, many had very poor vegetation cover. The herbaceous layer decreased with increasing altitude, which might be an indication that communities at higher elevations were harvesting more herbaceous medicinal plants, due to the lack of basic health care facilities. Therefore, special attention needs to be given to the conservation of medicinal plants in order to ensure their long-term availability to the local inhabitants. Data on the use of individual species of medicinal plants is needed to provide an in-depth assessment of the plants availability in order to design conservation strategies to protect individual species.

Comparative study on the structure of Cedrus deodara (Roxb. Ex Lambert.) G. Don forest in silvicultural felling and non-felling sites of Chakrata Forest Division

Vegetation composition, species diversity, Shannon-Wiener Index and regeneration behaviour of tree species in silviculturally managed felling and non-felling sites of the Deodar (Cedrus deodara (Roxb.ex Lambert.) G. Don forest of the Chakrata Forest Division, Uttarakhand, India was analysed. Plant density (plants ha-1) was higher in felling sites (350 ha-1) than the non felling sites (300 ha-1). Total basal cover (TBA, cm2 100 m-2) was also found higher in felling sites (7375) than non-felling site (3949). The diversity index and species richness were higher for shrubs and herbs at felling site. Dominant species (Cedrus deodara) has shown good regeneration potential as evidenced by the presence higher sapling and seedlings in felling site. Canopy opening by felling operation created the route for the invasion of the new shrub and herb species and regeneration of dominant tree species at felling site.

Composition and diversity of five major forest types in moist temperate climate of the western Himalayas

The present study was undertaken in five major forest types (dominated by Quercus semecarpifolia, Quercus floribunda, Acer acuminatum, Abies pindrow and Aesculus indica, respectively) between 2400 and 2850 m a.s.l. in a moist temperate forest of the Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim was to assess the variation in composition and diversity in different vegetation layers, i.e., herb, shrub and tree, among these five forest types. Diversity indices, such as the Shannon-Wiener diversity index, density, total basal cover, Simpson’s concentration of dominance index, Simpson’s diversity index, Pielou’s equitability, species richness, species heterogeneity and β-diversity, were calculated to understand community structures. Dominance-diversity curves were drawn to ascertain resource apportionment among various species in different forest types.

Stand structure, phenology and fruit yield of Illicium griffithii in western Arunachal Pradesh, North-East India

Illicium griffthii is an important medicinal tree species of the temperate broad-leaved forests of Northeast India. The species has high demands for its fruits. In view of scanty information on the species in natural stands, this investigation explores three forest stands under different management regimes in Western Arunachal Pradesh with particular reference to study stand structure, fruit production and phonological behaviour of I. griffthii. The study revealed that I. griffthii was an important species in the middle storey and it grew frequently with other top canopy species. The tree species richness, stand density and total basal cover of three stands varied between 27 to 40 species, 482 to 568 tree ha-1, and 18.08 to 59.28 m2 ha-1, respectively. The data showed that high biotic pressure resulted decline in tree species richness, stand density and total basal area while moderate level of pressure was beneficial. The contribution of I. griffthii to total stand density and basal cover was high at all three forests. It was interesting to note that these forests supported 72-81% tree species used for fuel, fodder, timber, edible fruits and other useful products, thus provided diverse opportunities to communities to visit these stands. The dominance-diversity curve showed that the resource allocation were homogenous to shared by a few species at different stands. Tree girth class structure showed that all forest stands are still evolving. The phenological progression of I. griffithii showed no marked leaf fall event, the flowering phase prevailed between February to April and mature fruits in October. The fruit yield for I. griffithii varied from 0.015 kg to 23.28 kg per tree for 11 to 180 cm girth class individuals. The study concluded that in view of high demand of fruits of I. griffithii, these forests may face higher pressure in near future, therefore information on stand structure, phenology and fruit productivity would help the management planners. It is suggested that if local communities could be educated about the potential of I. griffithii and promoted in agroforestry systems, the income of local farmers could be increased substantially, at the same time the species could be conserved in natural stands.

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.

Role of physiographic factors in distribution of Abies pindrow (Silver Fir) along an altitudinal gradient in Himalayan temperate forests

We have made an attempt to understand the significance of physiographic factors viz., altitude, aspect, slope and soil characteristics in determining the structure, composition, growth behavior and distribution of Himalayan Silver Fir (Abies pindrow Spach.) through a comparative analysis of two temperate forests. The occurrence of highest density (370 and 225 ind/ha), importance value index (213.10 and 190.60) and total basal cover (TBC; 95.72 and 51.15 m2/ha) values along with the availability of higher organic carbon (6.53 and 4.47%), nitrogen (N; 0.73 and 0.44%) and potassium (K; 621 and 319 ppm) contents in the soils just beneath the hilltops (2,650–2,800 and 2,550–2,650 m asl), on steeper slopes (45°–50° and 42°–45°) and North-East aspects have revealed better growth of A. pindrow on both the sites. Stem density positively correlated with TBC (0.771), Shannon–Wiener diversity index (H′; 0.879), OC (0.601), N (0.758) and K (0.752), whereas TBC has shown significant positive relationship with H′ (0.894), K (0.793) and N (0.716). Similarly, H′ has also shown significant positive correlation with slope (0.721), K (0.855) and N (0.791). Interestingly, positive correlation of altitude with stem density (0.557) and of slope with TBC (0.608) was noticed in the distribution of A. pindrow individuals.

Response of understory vegetation and soil moisture to infrequent heavy defoliation of chemically thinned juniper woodland

Targeted grazing programs that use small ruminants to control invasion of undesired woody plants are increasing across western North America. However, information regarding the potential impact of these herbivory regimes on non-target vegetation is lacking. We conducted a study in central New Mexico to determine the effects of removing all above-ground herbaceous biomass during winter in plots located beneath (under-canopy) or close to (inter-canopy) live one-seed juniper trees ( Juniperus monosperma) or dead tree snags that had been chemically treated 10 years previously. In under-canopy plots (defoliated in 2005 and 2006) understory herbaceous cover was not affected by the defoliation treatment; however, biomass production of Bouteloua gracilis and other perennial grasses decreased. In inter-canopy plots (defoliated in 2006), the defoliation treatment increased total herbaceous cover in plots between live trees, whereas biomass production was not affected. Simulated infrequent targeted grazing in a juniper woodland had slight detrimental effects on non-target plants in under-canopy plots by decreasing biomass production of native grasses under dead and live trees but had positive effects on inter-canopy plots by increasing total herbaceous basal cover. Superficial volumetric water content was not affected by the defoliation treatment, suggesting that simulated targeted grazing does not increase superficial soil moisture.

Vegetation structure, composition and diversity in relation to the soil characteristics of temperate mixed broad-leaved forest along an altitudinal gradient in Garhwal Himalaya

The focus of the study is to characterize the structure, composition and diversity of Banj Oak ( Quercus leucotrichophora ) forests at different altitudes and slopes in Mandal-Chopta area of Garhwal Himalaya. Competing co-dominant tree layers comprised of Persea duthiei and D. himalense at the higher altitude (2100m a.s.l.) and steeper slope (45°); D. himalense and Betula alnoides at the middle altitude (1700m a.s.l.) and moderate slope (38°); and Lyonia ovalifolia and Myrica esculenta at lower altitude (1550m a.s.l.) and gentles slope (30°) were observed in these forests. Community diversity was highest (3.140) at the higher altitude (site-1) whereas the concentration of dominance followed the opposite trend of the diversity. Physico-chemical properties of soils have revealed that availability of higher average total nitrogen and moisture contents might have given birth to higher total basal cover values at middle altitude. The tree density was positively correlated with the tree diversity and tree richness (P<0.001). The vegetational parameters A/F ratio, Shanon-wiener index, Species richness, Margalef index and soil parameters especially pH and available phosphate (kg/ha) were significant (P<0.05%) among the forest sites.

Plant and soil diversities in a sub tropical forest of the Garhwal Himalaya

The forest plays a significant role in influencing the structure of the soil by adding organic matter and also affects its basic status and nutrient level. The ability of the soil to retain and the percolation of water depend upon the percent amount of sand, silt and clay. Biotic disturbances generally have caused substantial reduction in forest cover. It has been observed that among the aspects the regeneration status of species was poor. A number of studies relating to regeneration of either specific species or the forest stand as a whole have focused on the impact of anthropogenic factors and natural disturbances. In general, human interference and other causative factors such as grazing, browsing, trampling are severely affecting the regeneration of this region. The study sites were dominated by Anogeissus latifolia, which is the most important fodder, fuel wood and timber tree for local people. Therefore, the heavy pressure of villagers by lopping of leaves, cutting new saplings and tree branches especially for firewood, are leading to poor regeneration. Among the aspects the average range of values of soil pH (6.33 to 6.47), soil organic carbon (0.47 to 0.68 %), phosphorus (9.67 to 10.67 Kg ha-1) and potassium (141.87 to 172.48 Kg ha-1) were recorded. The total highest density of tree layer (380 trees ha-1) was observed on south aspect, whereas the lowest (260 trees ha-1) was recorded on west aspect. In shrub layer, the total highest density (1790 shrubs ha-1) was recorded on east aspect and the lowest (970 shrubs ha-1) on west aspect. The range of values of total density and total basal cover of saplings were 200 to 550 saplings ha-1 and 0.78 to 1.43 m2 ha-1 respectively. Similarly for seedlings layer, these values ranged from 80 to 430 seedlings ha-1 and 0.01 to 0.034 m2 ha-1 respectively. The values of similarity among the aspects and different layers ranged from 25.0 to 66.67%, 22.22 to 57.14%, 28.57 to 57.14% and 57.14 % to 72.72% for trees, saplings, seedlings and shrubs respectively. The range of diversity was 0.846 to 1.710 (trees), 1.943 to 2.847 (shrubs), 1.10 to 1.520 (saplings) and 0.496 to 1.435 (seedlings). Keywords: Diversity, disturbance, layer, Anogeissus latifolia, Garhwal Himalaya Ghana Journal of Forestry Vol. 19 & 20 2006: pp. 1-19

Phytosociological analysis of the restored Sal (Shorea robusta) plantations and natural sal forest of Tripura

Among the existing activities in managing tropical forests, conservation efforts for Sal (Shorea robusta) forest in Tripura have virtually offered very valuable results. 68 plant species belonging to 41 taxonomic families were identified in such study areas. Remarkable dissimilarity between the stands of the restored coppice crop (7 and 16 years) and natural forest (approx. 45 years) was observed. Ground flora of young coppice crop was enriched with herb species while the density of shrubs and woody climbers was higher in the natural stand. Density per ha of herbs, shrubs and trees varied between 168000-497800, 18800-42112, 1100-2975 respectively. Total basal cover (m2 per ha) of herbs, shrubs and trees ranged between 0.524-0.941, 0.138-0.952, 2.333- 86.295 respectively. In the shrub layer 24.9% to 46.2% of the density and 53.4-81.6% of the Total Basal Cover (TBC) was shared by saplings belonging to economically and medicinally important tree species. It also indicates the regeneration potential of the area. Diversity index (Shannon Wiener Index) varied between 0.918- 0.967 for herbs, 0.743-0.876 for shrubs and 0.859 for trees. Values of Jaccard Similarity index were between 33-80% in herb layer, 22-48% in shrub layer, 14-100% in tree layer. The study brings out that the distribution of most of the species was random to contagious. Important flora viz. Smilax zeylanica, Vitex peduncularis, Ziziphus rugosa were the common species of the plant community on account of intact natural habitat.

Pasture management in semi-arid tropical woodlands: dynamics of perennial grasses

The effects of a range of pasture management options (introduced legumes and grasses, superphosphate, timber treatment, cultivation before sowing and stocking rate) on the basal cover of perennial grasses were measured from 1982 to 1991 at two sites, ‘Hillgrove’ and ‘Cardigan’, near Charters Towers, in north-east Queensland. Colonisation and survival of eight native and exotic grasses were followed in permanent quadrats in a subset of treatments. Overall, there were significant changes in total basal cover of plots between years and with tree killing, but no significant differences in sown pastures, fertiliser or stocking rate. Basal cover increased when defoliation levels were less than 40% but increases were smaller at higher levels of defoliation and basal cover often declined when defoliation was greater than 60%. Basal cover declined when growing seasons were &lt;10 weeks, remained static with 10–15 weeks growth, and increased when growing seasons were 16 weeks or longer. There was some colonisation in all years but large differences between years. The differences in colonisation between systems were generally small but there was a general trend for higher colonisation at higher stocking rates. Bothriochloa ewartiana (Domin) C.E.Hubb. and Chrysopogon fallax S.T.Blake had low, Heteropogon contortus (L.) P.Beauv. ex Roem.&amp;Schult., Cenchrus ciliaris L. and Aristida spp. had intermediate, and Bothriochloa pertusa (L.) A.Camus and Urochloa mosambicensis (Hack.) Dandy had high colonising ability. Survival of individual species was generally similar at both sites except for Urochloa mosambicensis. Heteropogon contortus and U. mosambicensis at ‘Hillgrove’ were short-lived (&lt;10% survival after 4 years), B. ewartiana, Themeda triandra Forssk. and Aristida spp. had intermediate survival (10–50%), and C. ciliaris, C. fallax, B. pertusa and U. mosambicensis at ‘Cardigan’ were long-lived (&gt;50% survival). Annual survival rates increased with plant age, were higher in good growing seasons than in poor seasons, were higher for large plants than small plants, and were lower at high defoliation levels than where defoliation was less severe. The differences between species in ability to colonise and survive, and the small influence of management compared to seasonal effects on survival, are discussed to explain species performance in pastures.

Habitat, food, and small mammal community structure in Namaqualand

The effect of habitat differences and food availability on small mammal (rodent and elephant shrew) species richness, diversity, density and biomass was investigated in Namaqualand, South Africa. Species richness in the three habitats sampled, namely Upland Succulent Karoo, Dry Riverine Shrub and North-western Mountain Renosterveld was low, with only 2–4 species per habitat. Rodents trapped were predominantly Gerbillurus paeba and Aethomys namaquensis, with fewer Mus minutoides and Petromyscus sp. The only non-rodent was the elephant shrew Elephantulus edwardii. Ten habitat features, the percentage of total plant cover, tree cover, shrub cover, grass cover, plant litter, total basal cover, sand, gravel or rock cover, and the dominant plant height were recorded at 30 randomly chosen points on five sampling grids in each habitat. Small mammal density and biomass was significantly correlated with food availability (green foliage cover, seeds, and relative density and biomass of insects). Species richness and diversity of small mammals were significantly correlated with shrub cover. Numbers and biomass of specific species correlated significantly with different habitat features in each case.