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1.
Hymenachne panduranganii, a new species of Poaceae collected from a wetland area of Wayanad Wildlife Sanctuary in Kerala, which constitutes the core area of Nilgiri Biosphere Reserve (NBR), is described and illustrated. The new species differs from the related species H. assamica in having 1.0–1.5 m tall culms, 3.7–4.0 mm long spikelets, floret with a distinct lower palea and having only 2 stamens. To further enunciate the differences, an identification key to the Indian species of Hymenachne is provided.  相似文献   

2.
This paper presents data on the impact of biotic pressure in terms of grazing by livestock and wood cutting by humans on the plant community in the Nilgiri Biosphere Reserve of India. Grass, and herbaceous plant biomass, number of cattle dung piles, number of woody stems available and damaged by human activities and weed biomass were assessed at different proximity along transects radiating from village-forest boundary to forest interior to measure the ecological impact of livestock grazing and fire wood collection. The grass biomass was positively correlated to overgrazing indicating the adverse effect on natural vegetation by cattle. Woodcutting was intense along the forest boundary and significantly declined as distance increased. Similarly, weed biomass and number of thorny species declined positively with proximity from village-forest boundary and the weed biomass was significantly higher in the pastoral sites compared to residential sites. The results suggest that human impact adversely affects natural vegetation and promotes weed proliferation in forest areas adjoining human settlements in the ecologically important Nilgiri Biosphere Reserve. Continued anthropogenic pressure could cause reduction in fodder availability to large herbivores like elephants, which in turn leads to an increase in human–elephant conflict.  相似文献   

3.
4.
Sri Lanka has a long tradition of forest product use. The relationship of people with a dry zone forest was studied using a sample of 48 households in two villages that varied in distance to the forest and access to the market. All households interviewed collected subsistence forest products and a majority of them also collected commercial products. The daily peak-season income from commercial gathering was 4.5 to 7.7 times the daily labor wage. There is a strong gender specialization, with commercial gathering dominated by men whereas subsistence gathering is almost exclusively the task of women. The average forest-derived household income in the village closer to the forest and with better market access was nearly double that of the other village. Family size as a proxy of labor availability was the main discriminating factor between those households who did and those who did not gather commercial products. A small inverse relationship between forest gathering and size of household agricultural land (particularly paddy rice) was observed. No clear relationship was found between total household income and forest derived income, contradicting the view that commercial forest gathering is an exclusive activity of the poorest households.  相似文献   

5.
A multi-proxy case study conducted on Central Asia's most isolated mountain forest sheds light on the apparent decline of forest in the Subboreal time period and the incisive environmental changes from dark taiga to steppe in the Gobi Altay of Southern Mongolia over the last 5000 yr.

New vegetation records from the ‘Gobi Gurvan Saykhan’ (43°30′ N/103°10′ E) reveal long distance disjunctions of birch–willow forests as well as a number of herbaceous forest plants. Thus the question arises as to whether long-distance dispersal or fragmentation, following climatic changes and human interference, are more plausible explanations for such a pattern. Analysis of current plant distribution patterns lead to conclusions which are corroborated by zoological surveys of the Gobi Altay: During the Holocene, dark taiga forests apparently existed approximately 600 km to the southeast of their present range, and pollen analysis and charcoal remains provide evidence of a forest decline during the Subboreal time period. The presence of humans during these environmental changes is highly probable as pollen indicating human presence was found. Thus, it is assumed that humans at least contributed to the subboreal forest decline and the spreading of sagebrush and pastures. Moreover we cannot rule out with certainty that disjunctions of forest flora between the Gobi Altay and the forests of north-eastern Tibet are indicative of migration through the present North China desert, as forests may have partly replaced deserts during the moister periods of the Holocene. This multidisciplinary approach implies a mid-Holocene and subboreal scenario, which is new for Central Asia and more in accordance with the environmental history of the Holocene in the western desert belt of the Old World.  相似文献   


6.
Sundarbans Biosphere Reserve (SBR) is the world's largest contiguous conserved mangrove forest with unique flora and fauna, but it still has to bear the brunt of anthropogenic disturbances due to huge population pressure. This study aimed to identify the sources, extent of metal pollution (Cd, Cr, Mn, Ni, Pb, and Zn), and their potential ecological risk in this fragile ecosystem. Sediments were collected from 10 locations with varied levels of anthropogenic pressure from the fringe of the reserve forest. Cluster analysis (CA) and factor analysis (FA) identified Ni, Cd, and Pb as the major anthropogenic pollutants in this area. Concentrations of Pb (27.79–47.07 mg/kg) and Cd (0.8–3.3 mg/kg) were found to be higher in areas reliant on fossil fuel-operated motorboats for transport and dependent on rechargeable batteries to cope with the shortage of electricity. The contamination factor (Cf), geoaccumulation index (Igeo), and ecological risk index (ERI) highlight that populated areas are mostly exposed to Cd, Pb, and Cr contamination. Interpolation maps identified that the central part of the area is acutely affected by Cd pollution, whereas the main ecotourism routes within the reserve forest have high Pb concentrations. This study concludes that conservation-friendly ecotourism and improper disposal of batteries can also pose a threat to this ecosystem and these possibilities could be considered during formulation of conservation plans.  相似文献   

7.
The energy dynamics in Thiashola grassland, a montane subtropical vegetation in Nilgiri Biosphere Reserve, the Western Ghats, India is studied for a period of one year. The study revealed that the energy content in unit biomass of C3 and C4 species has not varied significantly. However, the C4 species in total due to higher net primary production, entrapped 8.5 times greater solar energy (28.82 kcal/m2/day) than that of their C3 counterparts. Of the total energy fixed, the C3 and C4 species, respectively channeled 4.07 kcal/m2/day and 13.3 kcal/m2/day to the aboveground standing live compartment. The transfer rate of energy to standing dead compartment from standing live part were 3.22 kcal/m2/day and 10.36 kcal/m2/day for C3 and C4 species, respectively and both the C3 and C4 together transferred 4.81 kcal/m2/day of energy from standing dead to litter compartment. The total dissipation of energy from the system is determined to be 4401.11 kcal/m2/yr and the surplus quantity of 38.37% of energy is accumulated in the aboveground parts of both C3 and C4 species which indicates the availability of substantial amount of energetic fodder to the wild herbivores in the Thiashola grassland.  相似文献   

8.
9.
The energy dynamics in Thiashola grassland, a montane subtropical vegetation in Nilgiri Biosphere Reserve, the Western Ghats, India is studied for a period of one year. The study revealed that the energy content in unit biomass of C3 and C4 species has not varied significantly. However, the C4 species in total due to higher net primary production, entrapped 8.5 times greater solar energy (28.82 kcal/m2/day) than that of their C3 counterparts. Of the total energy fixed, the C3 and C4 species, respectively channeled 4.07 kcal/m2/day and 13.3 kcal/m2/day to the aboveground standing live compartment. The transfer rate of energy to standing dead compartment from standing live part were 3.22 kcal/m2/day and 10.36 kcal/m2/day for C3 and C4 species, respectively and both the C3 and C4 together transferred 4.81 kcal/m2/day of energy from standing dead to litter compartment. The total dissipation of energy from the system is determined to be 4401.11 kcal/m2/yr and the surplus quantity of 38.37% of energy is accumulated in the aboveground parts of both C3 and C4 species which indicates the availability of substantial amount of energetic fodder to the wild herbivores in the Thiashola grassland.  相似文献   

10.
Southern Africa's subtropical forest biome, though small and highly fragmented, supports much of the region's biodiversity. With limited resources available for conservation and the exploitative use of forest escalating, identifying a network of priority forest reserves is important. We examine the distribution of forest birds, butterflies and mammals in KwaZulu-Natal, South Africa. Using an iterative algorithm we explore the efficiency of existing protected areas, species richness and rarity hotspots, prime forest sites (selected by forest area) and complementary networks as alternative approaches to priority reserve selection, as well as the potential use of indicator taxa. Existing protected areas represent 98% of species but are relatively inefficient in terms of area. Alternative selection criteria represent a high proportion of species (86–92%) and provide efficient bases for developing fully representative reserve networks. All species are represented within a network of 22 complementary quarter degree cells. This network includes several larger forests and existing protected areas and is recommended for priority conservation. Complementary networks identified separately for birds, butterflies and mammals overlap little, but each represents a high proportion of the remaining taxa, supporting their potential as representative 'indicator' taxa. The evolutionary history of the three main forest types in KwaZulu-Natal explains observed spatial patterns of alternative reserve networks. Priority areas are concentrated in scarp and coastal forest belts, regions of comparatively recent evolutionary activity with high species richness. Afromontane forest is older and less diverse, but its inclusion in any reserve network is necessary for the full representation of forest diversity.  相似文献   

11.
Tropical forest ecosystems are among the most essential habitats on Earth for conserving biological diversity and short-term climate regulation. For this reason, they are key areas of conservation policies in the world. In this paper, we aim to investigate the dynamics of forest cover and their changes in primary productivity by empowering information on historical forest management and fieldwork research with remote sensing vegetation monitoring methods. The study area falls within the central portion of the Indian Western Ghats, a global biodiversity hotspot. In particular, part of the analysis was performed on the Kadamakal Reserve Forest and Pushpagiri Wildlife Sanctuary, which harbours an endemic low elevation dipterocarp evergreen forest. This area was managed by selective logging and became fully protected in 1984. We performed multiple time series macroscale analyses between 1999 and 2020 on the Indian Central Western Ghats region, using satellite products at 1 km spatial resolution from the VITO Copernicus Global Land Service on Dry Matter Productivity, Fraction of Absorbed Photosynthetically Active Radiation, and Normalised Difference Vegetation Index. We also performed a very-high spatial resolution Normalised Difference Vegetation Index differential analysis between 2021 and 2016 with Sentinel 2-L2A products to investigate forest dynamics within the reserve. At the 1 km spatial resolution has been found an increase in all three vegetation indices, by employing the LOESS statistical method for the smoothed transition autoregressive model of raster data medians of our datasets. The boxplot raster distribution analysis also highlighted a significant imbalance in dry matter productivity in the last decade (2010−2020) comparing the previous one (1999–2009). The second part of the analysis, at 10 m spatial resolution within the reserve forest, revealed a growth in the vegetation cover on the top of the Pushpagiri Mountain ridge and in a previously landslide area. The study found new erosion channels down to the upper plateau on the South-West side of the reserve due to an increment of the run-off processes during the monsoon period. This satellite analysis highlighted generalised positive vegetation trends in the Central Western Ghats, India, over the last twenty-two years, enhancing an improvement in the ecosystem functioning and carbon storage ecosystem service. Notably, through this work, we also developed a standardised and open-access framework to monitor the vegetation remotely (SVIT) during periods of forest inaccessibility for fieldwork sampling.  相似文献   

12.
A method of field application of strontium chloride (SrCl2) and the assessment of local dispersal of marked Helicoverpa armigera moths in a mark-capture experiment in southern India are described. A 1.7 ha field of pigeonpea sustaining a population of approximately 400,000 larvae was treated with a single application of SrCl2 plus surfactant at 10 kg/ha, using a motorised high volume sprayer. An estimated 50,400 moths emerging over a 20 day period were unequivocally marked with Sr at a marking efficiency of 55%. Catches of moths in an array of 14 battery operated light traps and 29 pheromone traps, up to 3.5 km distant were analysed by atomic absorption spectrophotometry. Low recaptures of marked moths (7%) in the treated field suggested the rapid exodus of emergent moths, even while the crop remained attractive, and their dilution or replacement by immigrants. The distribution of marked moths in lights and pheromone traps is consistent with a predominantly downwind dispersal close to the ground during the early part of the night and more random movement later on.
Résumé L'exposé concerne une méthode de traitement en champ des chenilles par le chlorure de strontium (SrCl2) et de la mesure de la dispersion locale des papillons marqués de H. armigera Hübner (Lépido.: Noctuida) dans le sud de l'Inde. Un champ de 1,7 ha de C. cajan (cultivar ICPL138) qui hébergeait une population d'environ 400 000 chenilles a été traité en une seule fois avec un pulvérisateur motorisé de forte capacité à raison de 10 kg/ha de SrCl2 additionné de 0,1% Triton X-100 comme surfactant. 55% des 50 400 papillons émergeant sur une période de 20 jours étaient sans ambiguïté marqués au strontium. Les papillons, capturés dans des rangées de 14 pièges lumineux et 33 pièges à phéromones attractifs jusqu'à 3,5 km, ont été examinés au spectrophotomètre à absorption atomique. Les faibles recapturés (7%) dans le champ traité suggèrent un rapide exode des mouches ayant émergé ou leur remplacement par des immigrants. Les captures révèlent, au début de la nuit, une dispersion majoritairement dans le sens du vent, près du sol et, plus tard dans la nuit, un mouvement plus au hasard.
  相似文献   

13.
Blood samples from 103 Kotas and 58 Badagas residing in the Nilgiri Hills, South India, were examined for HLA-A and -B antigen profiles. The Kota group was characterized by fairly high frequencies of A2 and B7 antigens as well as the haplotype A2-B7. The frequencies of Aw19, A28, and Bw22 were found to be higher in Badagas than in Kotas. The results are compared with the literature available on other Indian populations.  相似文献   

14.
This study concerns the thermotolerance of spores of mesophilic fungi isolated from a tropical semi-arid habitat subject to dry season fire in the Western Ghats, southern India. Among 25 species of Ascomycota isolated from leaf litter, nine were able to grow after incubation in a drying oven for 2h at 100°C; the spores of two of these species survived 2h incubation at 110°C, and one survived exposure to 115°C for 2h. The range of thermotolerance among mesophilic fungi isolated from the leaf litter was surprising: filamentous fungi from other habitats, including species that colonize scorched vegetation after fires and thermophilic forms occurring in self-heating plant composts, cannot survive even brief exposure to such high temperatures. It is possible that the exceptional heat resistance of the Indian fungi is related to adaptations to surviving fires. Genetic analysis of the physiological mechanisms of heat resistance in these fungi offers prospects for future biotechnological innovations. The discovery of extreme thermotolerance among common saprotrophs shows that this physiological trait may be more widespread than recognized previously, adding to concern about the evolution of opportunistic pathogens on a warmer planet. The fungi in this study are among the most heat-resistant eukaryotes on record and are referred to here as 'Agni's Fungi', after the Hindu God of Fire.  相似文献   

15.
Several fast‐growing and multipurpose trees such as exotic and valuable native species have been widely used in West Africa to reverse the tendency of massive degradation of plant cover and restore soil productivity. Although benefic effects have been reported on soil stabilization, a lack of information about their impact on soil symbiotic microorganisms still remains. This investigation has been carried out in field trees of 28 years old in a forest reserve at Bandia. To determine the mycorrhizal inoculum potential (MIP) of soils, a mycorrhizal bioassay was conducted using seedlings of Zea mays L. Spores concentration, arbuscular mycorrhizal (AM) fungi morphotypes and mycorrhizal colonization of field plants were examined. Results showed that fungal communities were dominated in all samples by the genus Glomus. Nevertheless, the others genera Gigaspora and Scutellospora occurred preferentially out of the plantations. The number and richness of spores as well as the MIP of soils were decreased in the tree plantations. Accordingly, the amount of annual herbaceous plants kept out of the tree plantations was much greater than those under the tree plantations. The colonization was higher in field root systems of herb plants in comparison with that of the tree plants. Comparisons allowed us to conclude that vegetation type modifies the AM fungal communities, and the results suggest further adoption of management practices that could improve or sustain the development of herbaceous layers and thus promote the AM fungal communities.  相似文献   

16.
K. S. Murali  R. Sukumar 《Oecologia》1993,94(1):114-119
Patterns of leaf-flushing phenology of trees in relation to insect herbivore damage were studied at two sites in a seasonal tropical dry forest in Mudumalai, southern India, from April 1988 to August 1990. At both sites the trees began to flush leaves during the dry season, reaching a peak leaf-flushing phase before the onset of rains. Herbivorous insects emerged with the rains and attained a peak biomass during the wet months. Trees that flushed leaves later in the season suffered significantly higher damage by insects compared to those that flushed early or in synchrony during the peak flushing phase. Species whose leaves were endowed with physical defenses such as waxes suffered less damage than those not possessing such defenses. There was a positive association between the abundance of a species and leaf damage levels. These observations indicate that herbivory may have played a major role in moulding leaf flushing phenology in trees of the seasonal tropics.  相似文献   

17.
This study documents the utilization aspects and distribution of ethnobotanical knowledge of the local people of Morogoro, Tanzania, as a first step towards sustainable utilization and conservation of tropical woodlands. A total of 133 arborescent species in 31 families was identified of which 69% had a variety of uses. These uses were classified into 12 categories and major uses were charcoal, firewood, medicine, and poles. Most tree species have occasional uses, but a few are exceptionally useful and thus their levels of utilization may far exceed their regeneration and production. The questionnaire survey indicated that 62% of the respondents agreed that traditional medical services were more available than modern services. Utilization surveys indicated that wooden poles are the building material used in 98% of the dwellings and storage structures, wild foods were useful for food security especially during drought years, and high quality timber trees have been depleted in the forest because of earlier exploitation by pit-sawing. The distribution of ethnobotanical knowledge indicated that much of the relevant ethnobotanical and utilization information was held by more aged members of the society and hence there is a clear need to capture this knowledge before it is lost. This study has shown that resources are defined by use and culture, and some components of ethnobotanical knowledge have potential for the sustainable management of miombo woodlands.  相似文献   

18.
As natural forest cover declines, planted forests have come to occupy an increasing percentage of the earth's surface, yet we know little about their suitability as alternative habitat for wildlife. Although some primate species use planted forests, few studies have compared primate populations in natural and nearby planted forests. From March 2006 to July 2010, we conducted line transect surveys and assessed group sizes and compositions in natural and nearby 60-70 year old mixed indigenous planted forest to determine the densities of diurnal primate species (Colobus guereza, Cercopithecus mitis, C. ascanius) in these two forest types at Isecheno, Kakamega Forest, Kenya. Line transect data were analyzed using the Encounter Rate, Whitesides, and Distance sampling methods, which all provided broadly consistent results. We found that all three diurnal primate species occupy both natural and planted forest at Isecheno. However, group densities of the two Cercopithecus species were 42-46% lower in planted than in natural forest. Colobus guereza achieved comparable group densities in the two forest types, although the species is found in smaller groups, and thus at lower (35%) individual density, in planted than in natural forest. Following a logging episode in the planted forest mid-way through our study, Cercopithecus ascanius group densities fell by 60% while C. mitis and Colobus guereza group densities remained stable over the next two years. Overall, our results suggest that while primate species vary in their response to habitat disturbance, planted forest has the potential to contribute to the conservation of some African monkey species. Even for the relatively flexible taxa in our study, however, 60-70 year old mixed indigenous planted forest failed to support densities comparable to those in nearby natural forest. From the perspective of Kakamega's primates, planted forests may supplement natural forest, but are not an adequate replacement for it.  相似文献   

19.
《农业工程》2022,42(2):68-73
Corbett Tiger Reserve (CTR) supports several important species such as the tiger (Panthera tigris), leopard (Panthera pardus), elephant (Elephas maximus), and sambar (Cervus unicolor). Some of the species are involved in crop damage, livestock depredation, and human injuries or causalities, causing economic and social losses. Tigers and leopards are perceived as the major threat, causing economic losses to the people living around the protected areas (PAs), because of livestock depredation. Alternatively, the local community also draws benefits from the forest, which are seldom considered part of their economy. Here, we assessed the economic losses and benefits to the people at the northern periphery of the CTR based on semi-structured questionnaire survey of 301 respondents in 26 villages, between January and June 2018. We also determined the socio-economic factors associated with forest dependency using Ordinary Least Square regression (OLS). Most respondents (98%) reported reliance on the forest for fuelwood, fodder, and cattle grazing. Income from forest resources (US$ 1102.2 ± 63.6/hh/yr)2 contributed significantly to the livelihood of the people (26.5 ± 1.3%). The income from fuelwood (US$ 188.1 ± 2.2/hh/yr), fodder (US$ 335.0 ± 10.0/hh/yr) and livestock grazing (US$ 618.1 ± 59.9/hh/yr) contributed 5.6 ± 0.3%, 9.3 ± 0.6%, and 11.6 ± 1%, respectively, to the household's total income. Reliance on forest resources was positively associated with the number of livestock and female participation in resource extraction, and negatively with the employment, age, education of respondents, and use of modern source of energy -Liquid Petroleum Gas. People incurred a cost of US$ 110.5 ± 4.7/hh/yr due to livestock depredation. It was estimated that benefits drawn from the forest exceed the losses incurred due to livestock depredation. Therefore, we recommend that a cost-benefit analysis is essential before designing conflict mitigation strategies. Since the compensatory schemes in India have largely struggled to achieve their objectives, it is, therefore, emphasised to find other measures, such as payment of ecosystem services (PES), to reduce conflict for maintaining a peaceful co-existence of human and carnivores.  相似文献   

20.
《农业工程》2021,41(6):545-551
The floristic life-form spectrum of any area unveils the prevailing phytoclimatic conditions, helps in understanding the species-environment relationship and can be applied to compare the vegetation pattern of one eco-zone to another. We scrutinized the pattern of species richness (SR) and floristic spectrum along the elevation gradient in a biodiversity-rich eco-zone of western Himalaya (western Ramganga valley, Uttarakhand, India) between 1200 m (river bank) to 3100 m a.s.l. (summit). The elevation range was classified into six elevation bands (i.e. <1500 m, 1500–1800 m, 1801–2100 m, 2101–2400 m, 2401–2700 m, >2700 m), to prepare the presence (1)/ absence (0) species data matrix using local distribution (elevation range) of each species to estimate the SR of various growth-forms and life-forms for the particular elevational band. The findings suggest that the correlation of SR with elevation is not linear as the species richness peaks at the middle elevation (humped-back shape relationship). The forest cover is large and continues up to the summit; thus, the correlation of tree and shrub SR with elevation is not clear; though, a partly positive correlation was observed between elevation and herb SR while negative correlation between climber SR and elevation. The percentage of phanerophytes and therophytes in total life-forms decreased significantly with increase in elevation while inverse trend was shown by hemicryptophytes and cryptophytes. The pattern of phytoclimate in the area varied from phanero-therophytic at the lower elevation to phanero-hemicryptophytic at the middle and hemicrypto-phanerophytic at the upper elevation. The present contribution is an attempt to fill the knowledge gap in pattern of growth-form, life-form and phytoclimate within the forest-covered montane zone of western Himalaya. It will be helpful in understanding the vegetation dynamics in mountain ecosystems and serve as a ready reference to planners in any future conservation strategy for the area.  相似文献   

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