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1.
Natural disasters pose a threat to isolated populations of species with restricted distributions, especially those inhabiting islands. The Nicobar long tailed macaque.Macaca fascicularis umbrosus, is one such species found in the three southernmost islands (viz. Great Nicobar, Little Nicobar and Katchal) of the Andaman and Nicobar archipelago, India. These islands were hit by a massive tsunami (Indian Ocean tsunami, 26 December 2004) after a 9.2 magnitude earthquake. Earlier studies [Umapathy et al. 2003; Sivakumar, 2004] reported a sharp decline in the population of M. f. umbrosus after thetsunami. We studied the distribution and population status of M. f. umbrosus on thethree Nicobar Islands and compared our results with those of the previous studies. We carried out trail surveys on existing paths and trails on three islands to get encounter rate as measure of abundance. We also checked the degree of inundation due to tsunami by using Normalized Difference Water Index (NDWI) on landsat imageries of the study area before and after tsunami. Theencounter rate of groups per kilometre of M. f. umbrosus in Great Nicobar, Little Nicobar and Katchal was 0.30, 0.35 and 0.48 respectively with the mean group size of 39 in Great Nicobar and 43 in Katchal following the tsunami. This was higher than that reported in the two earlier studies conducted before and after the tsunami. Post tsunami, there was a significant change in the proportion of adult males, adult females and immatures, but mean group size did not differ as compared to pre tsunami. The results show that population has recovered from a drastic decline caused by tsunami, but it cannot be ascertained whether it has reached stability because of the altered group structure. This study demonstrates the effect of natural disasters on island occurring species.  相似文献   

2.
Tropical islands are special and sensitive ecosystems which are subjected to various disturbances imposed by human activities and natural disasters. A detailed study about the changing landscape scenarios of these fragile island systems induced by various driving factors could be used for setting up measurements in support of conservation and sustainable development projects. The current research is a meta-analysis of the studies carried out in Andaman and Nicobar islands which analyzed the impact of tsunami of 2004 using geospatial tools. Based on the analysis, it was observed that the Nicobar islands were more affected compared to the Andaman islands. The majority of the researchers used pre- and post-tsunami satellite imagery and adopted visual interpretation method to delineate the changed classes. The study infers uplift of land in Andaman (exposing) and subsidence in Nicobar islands (inundation) with severe damage to the coastal elements like mangroves, coral reefs, plantations and in few cases interior forest. The analysis showed there were no records of the damage for some small islands. Finally, it is concluded that utility of microwave satellite data for change analysis will prove better in regions like Andaman and Nicobar where it is difficult to get cloud free optical data because of the high monsoon periods in these islands. It is also suggested that future work utilizing suitable temporal satellite imagery should focus on the extent of recovery of vegetation and other coastal elements which suffer the impact of disaster.  相似文献   

3.
A new species of wild banana, Musa paramjitiana L. J. Singh, from the Andaman Islands, India is described and illustrated, and its conservation status is assessed. A key to the species of Musa L. from Andaman and Nicobar Islands is also provided.  相似文献   

4.
Coastal vegetation has been widely recognized as a natural method to reduce the energy of tsunami waves. However, a vegetation barrier cannot completely stop a tsunami, and its effectiveness depends on the magnitude of the tsunami as well as the structure of the vegetation. For coastal rehabilitation, optimal planning of natural coastal systems, and their maintenance, we need to quantitatively elucidate the capacity of vegetation to reduce the energy of tsunami waves. The limitations of coastal forests in relation to the magnitude of a tsunami and the maintenance of forests as natural disaster buffer zones have to be understood correctly for effective coastal vegetation planning. Demerits of coastal forests have also been revealed: for example, an open gap in a forest (i.e., a road, river, difference in elevation, etc.) can channel and amplify a strong current by forcing it into the gap. Floating debris from broken trees also can damage surrounding buildings and hurt people. However, many studies have revealed that these demerits can be overcome with proper planning and management of mangroves and coastal forests, and that coastal vegetation has a significant potential to mitigate damage in constructed areas and save human lives by acting as buffer zones during extreme natural events. However, mangrove forests have been damaged by anthropogenic activities (i.e., tourism, shrimp farming, and industrial development), making coastal areas increasingly vulnerable to tsunamis and other natural disasters. The effectiveness of vegetation also changes with the age and structure of the forest. This highlights the fact that proper planning and management of vegetation are required to maintain the tsunami buffering function of coastal forests. Although many government and nongovernmental organizations have implemented coastal vegetation projects, many of them have been unsuccessful due to a lack of proper maintenance. A pilot project in Matara City, Sri Lanka, revealed that participation and support from local authorities and communities is essential to make the planting projects successful. An integrated coastal vegetation management system that includes utilization of the materials produced by the forest and a community participation and awareness program are proposed to achieve a sustainable and long-lasting vegetation bioshield.  相似文献   

5.
Bacillus thuringiensis (Bt) strains were isolated from soil samples of Great Nicobar Islands, one of the “hottest biodiversity hotspots,” where no collection has been characterized previously. The 36 new Bt isolates were obtained from 153 samples analyzed by crystal protein production with light/phase-contrast microscopy, determination of cry gene profile by SDS-PAGE, evaluation of toxicity against Coleopteran, and Lepidopteran insect pests, finally cloning and sequencing. Majority of the isolates showed the presence of 66–35 kDa protein bands on SDS-PAGE while the rest showed >130, 130, 73, and 18 kDa bands. The variations in crystal morphology and mass of crystal protein(s) purified from the isolates of Bt revealed genetic and molecular diversity. Based on the toxicity test, 50 % of isolates were toxic to Ash weevils, 16 % isolates were toxic to cotton bollworm, 38 % isolates were toxic both to ash weevil as well as cotton bollworm, while 11 % of the isolates did not exhibit any toxicity. PCR analysis unveiled prepotency of cry1B- and cry8b-like genes in these isolates. This study appoints the first isolation and characterization of local B. thuringiensis isolates in Great Nicobar Islands. Some of these isolates display toxic potential and, therefore, could be adopted for future applications to control some agriculturally important insect pests in the area of integrated pest management for sustainable agriculture.  相似文献   

6.
The palm resources of Andaman & Nicobar Islands are quite rich and unique with a substantial number of endemic species. Andaman & Nicobar Islands, falling within the Indo-Burma region constitute “hottest hotspot” of global biodiversity with an exceptional concentration of endemic species, but are experiencing alarming loss of habitat. The flora and fauna of Andaman group of islands show striking dissimilarities with that of Nicobar group. Palms such as Arenga pinnata, A. westerhoutii, Calamus baratangensis, C. basui, C. longisetus, C. palustris, C. viminalis, Corypha utan, Daemonorops aurea, D. kurziana, D. manii, D. rarispinosa, D. wrightmyoensis, Korthalsia rogersii, Licuala spinosa, Phoenix andamanensis, and Pinanga andamanensis which occur in Andaman groups of islands are absent in the Nicobar group of islands. While Bentinckia nicobarica, Calamus dilaceratus, C. nicobaricus, C. pseudorivalis, C. semierectus, C. unifarius, and Rhopaloblaste augusta are confined to the Nicobars, but seldom found in the Andamans. Areca triandra, Calamus andamanicus, Caryota mitis, Korthalsia laciniosa, Licuala peltata and Pinanga manii are widely distributed in both the group of islands. There is a considerable reduction in their natural population probably due to habitat destruction, low regeneration, and inability to compete with other plants. In addition, calamities like tsunami caused irrecoverable loss of valuable genetic diversity of palms. If conservation efforts are not undertaken, many of the existing species, if not all, are likely to disappear within a foreseeable future. There is dire need for habitat preservation and for in situ conservation. Appropriate conservation strategies should be taken to prevent further genetic erosion of these species and to protect these invaluable plant resources.  相似文献   

7.
Zingiber pseudosquarrosum L. J. Singh & P. Singh sp. nov. (Zingiberaceae) from Andaman and Nicobar Islands, India is described and illustrated and its conservation status is evaluated. This new species seems related to Z. squarrosum Roxb. but can be distinguished by the presence of a small pseudostem, long ligule and petiole, broadly lanceolate leaves with cuneate base, caudate apex and paxillate venation, urceolate or prolate inflorescences, very long underground peduncle, long calyx, very long corolla tube, labellum deep purple red (claret) at centre, orange red (vermillion) at lateral sides with ivory (off white) spots, tip truncate and slightly notched, margin folded back, stamen with short filament, yellow orange anther, light brown ovary, blood red (cinnabar) seeds covered by a white aromatic aril. A key to the species of Zingiber Mill. from the Andaman and Nicobar Islands is also provided.  相似文献   

8.
9.
A field study using satellite images was carried out to analyze the effect of coastal vegetation in mitigating the impact of a catastrophic tsunami on coastal villages in the Biobío Region, Chile, in February 2010. Two types of stand, Pinus radiata D. Don forests and Cupressus macrocarpa Hartw. shelterbelts, appear to have protected coastal areas behind them from the direct impact of the tsunami. The impacts of the horizontal and vertical structures of these coastal forests on the drag forces were analyzed by observing the characteristics of Pinus radiata forests and Cupressus macrocarpa shelterbelts. The stands absorbed the impact of the tsunami without incurring broken stems or uprooted trees due to their diverse horizontal structure, as they contained short trees with various diameters. However, small areas of the stands were damaged by salinity after the tsunami. For this tsunami, which was less than 3 m high, the horizontal and vertical structures of the P. radiata and C. macrocarpa stands provided effective protection for coastal villages since they reduced the velocity and height of the tsunami. A shelterbelt consisting of three rows of C. macrocarpa in front of the tsunami and a P. radiata forest with a density of 11 trees/100 m2 and a width of >50 m immediately behind the shelterbelt are suggested as a means of protecting communities along the coastline of the Biobío Region against tsunamis.  相似文献   

10.
The goal of biodiversity hotspots is to identify regions around the world where conservation priorities should be focused. We undertake a geographic information system and remote sensing analysis to identify the rarest and least protected forests in biodiversity hotspots. World Wildlife Fund ecoregions with terrestrial forest were subset from 34 biodiversity hotspots and forest cover calculated from GlobCover data at a 300?m pixel resolution. There were 276 ecoregions in 32 biodiversity hotspots classified as containing terrestrial forests. When the first quartile of forest ecoregions was subset based on smallest extent of forest cover in protected areas, there were 69 rare forests identified within 20 biodiversity hotspots. Most rare forest ecoregions (45) occurred on islands or island archipelagos and 47 rare forest ecoregions contained less than 10?% forest cover in protected areas. San Félix-San Ambrosio Islands Temperate Forests, Tubuai Tropical Moist Forests, Maldives-Lakshadweep-Chagos Archipelago Tropical Moist Forests, and Yap Tropical Dry Forests were identified as the least protected and possibly most vulnerable forests within biodiversity hotspots. These ecoregions cover less than 500?km2, forest cover is less than 50?km2, and there are no protected areas. There is a need to update classifications and boundaries of protected areas, insure that islands are included in global land cover datasets, and identify levels of endemism and endangerment within forest ecoregions. This should improve our ability to compare, prioritize, and monitor forests in biodiversity hotspots.  相似文献   

11.
Cycas dharmrajii L.J.Singh (Cycadaceae), a new species from the Andaman Islands, India is described and illustrated, and its conservation status is assessed. An abnormal branching habit of the giant trunk, its swollen base, often branched, polymorphic aerial roots, medium‐sized leaves, megasporophylls with well‐defined 10–28 paired lateral hook‐like structures and 1–3 pairs of ovules, 2‐schizo‐lysigenous mucilage canals in leaflet, and characteristic pitting on the periclinal walls of the epidermal cells of the leaflets distinguishes it from all previously known species. A key to the species of Cycas from the Andaman and Nicobar Islands is also provided.  相似文献   

12.
We surveyed the distribution and status of the long-tailed macaque (Macaca fascicularis umbrosa) in the Nicobar Islands of India. Long-tailed macaques live on 3 islands: Great Nicobar, Little Nicobar and Katchal. There are a total 788 groups. Group size ranged from 25 to 56 individuals with a mean size of 36. Long-tailed macaques are a multimale-multifemale society. Adult males, adult females and immatures constituted 9.7 per cent, 43.2 per cent and 47.1 per cent of the population, respectively. A fairly high ratio of immatures to adult females indicates a healthy population turnover. Vegetation parameters including tree density, canopy cover, canopy height and basal area indicated a still healthful habitats on all the 3 islands. We observed a few threats to the macaques. Measures should be undertaken to ensure survival of the Nicobar subspecies.  相似文献   

13.
Artificial drainage (ditching) is widely used to increase timber yield in northern forests. When the drainage systems are maintained, their environmental impacts are likely to accumulate over time and along accompanying management, notably after logging when new forest develops on decayed peat. Our study provides the first comprehensive documentation of long-term ditching impacts on terrestrial and arboreal biodiversity by comparing natural alder swamps and second-generation drained forests that have evolved from such swamps in Estonia. We explored species composition of four potentially drainage-sensitive taxonomic groups (vascular plants, bryophytes, lichens, and snails), abundance of species of conservation concern, and their relationships with stand structure in two-ha plots representing four management types (ranging from old growth to clearcut). We found that drainage affected plot-scale species richness only weakly but it profoundly changed assemblage composition. Bryophytes and lichens were the taxonomic groups that were most sensitive both to drainage and timber-harvesting; in closed stands they responded to changed microhabitat structure, notably impoverished tree diversity and dead-wood supply. As a result, natural old-growth plots were the most species-rich and hosted several specific species of conservation concern. Because the most influential structural changes are slow, drainage impacts may be long hidden. The results also indicated that even very old drained stands do not provide quality habitats for old-growth species of drier forest types. However, drained forests hosted many threatened species that were less site type specific, including early-successional vascular plants and snails on clearcuts and retention cuts, and bryophytes and lichens of successional and old forests. We conclude that three types of specific science-based management tools are needed to mitigate ditching effects on forest biodiversity: (i) silvicultural techniques to maintain stand structural complexity; (ii) context-dependent spatial analysis and planning of drained landscapes; and (iii) lists of focal species to monitor and guide ditching practices.  相似文献   

14.
Reefs of Andaman and Nicobar Islands harbour 418 species of scleractinian corals spread over an area of 2,000 km2. In April to May, 2010, due to the delayed onset of the southwest monsoon the sea surface temperature of the coastal and oceanic region increased to 31.7 °C in respect to the earlier record of maximum 29.0 °C during the said period. This resulted in mass bleaching of hermatypic corals during May, 2010. Rapid under water surveys have been conducted in reefs of Andaman and Nicobar Islands to assess the health of corals between May 2010 and August 2011. It is estimated that 76.62 ± (SD) 10.83 % of coral species are bleached up to a water depth of 10–15 m. Species from the genus Acropora appeared more susceptible to bleaching than those belong to the genus Porites. During the month of June 2010 the sea surface temperature was reduced to 29 °C perhaps due to the rainfall which stimulated rebuilding of zooxanthellae population in bleached corals. Recovery of 85.54 ± (SD) 6.33 % of bleached corals was seen during the study period of 11 months after the bleaching event. Porites spp. showed a high recovery rate, while Acropora spp. had the highest mortality rate. Coral mortality can have profound ecological and socio-economical implications and highlights the need for sustained monitoring for coral reef conservation in India. Hence, steps must be taken to improve management tools to protect these resources of global significance.  相似文献   

15.
Sacred areas are the oldest form of habitat protection, and many of these areas contribute to biodiversity conservation. While sacred groves have received considerable scholarly attention, little is known about fresh water swamps in the Western Ghats, India and sacred swamps have largely been ignored. This paper provides a first overview testing the conjecture that sacred swamps have physical features that distinguish them from non-sacred swamps. We assessed 110 fresh water swamps in the district of Uttara Kannada, Central Western Ghats, India, through extensive field surveys. Out of them 11 swamps are ‘sacred’ according to local testimony. Swamps are found in wet evergreen and evergreen forest types, but sacred swamps occur only in the wet evergreen forests. Sacred swamps differ significantly from non-sacred swamps with respect to size and shape, distance to the nearest road, human settlement, and commercial orchard, and population density within a radius of 500 m. This shows that preferentially swamps close to settlements, orchards and roads have been declared as sacred, probably to regulate the continuing provision of relevant ecosystem services. While we find a variety of deities associated with these sacred swamps, the practices associated with sacred swamp status and management are essentially the same across belief groups. However, the conservation practice is at risk due to migration dynamics.  相似文献   

16.
Natural areas near human-modified landscapes experience factors that may affect local biodiversity at levels commensurate with natural environmental factors. The land snails of the Canary Islands provide excellent opportunities to evaluate the importance of anthropogenic agents in mediating the diversity and distribution of species. Land snails are particularly sensitive to disturbance and are an integral part of terrestrial ecosystems. This study analyzed the distributions and abundances of terrestrial macrosnail shell assemblages at 60 localities throughout the coastal scrub biome of the Canary Islands. This was accomplished using data on natural and anthropogenic variables to assess their relative importance in governing land snail diversity. A total of 34,801 dead shells represented a diverse malacofauna with highly localized endemism. Due to uncertain species identifications, samples from the 18 sites from the two easternmost islands are described, but excluded from statistical analyses. Regression tree analysis indicated that proximity to agricultural sites was the most important predictor of species diversity. Sites with no or very little agricultural area (≤ 0.167 km2) within a 1 km radius had significantly higher richness and diversity. These results have implications for Canary Islands conservation. Protected areas that are patchworks of natural and agricultural landscapes are still subject to native biodiversity loss because of anthropogenic impacts even when the footprint of agriculture is small.  相似文献   

17.
Biogeographical studies are a necessary step in establishing conservation area networks. Determining the ecological factors influencing vegetation is also a basic principle for hierarchical ecological classifications and a necessary prerequisite for ecosystem-based land use planning. Eco-floristic sectors (EFS) have already been identified for the Indonesian island of Sumatra, combining both approaches, dividing it into 38 EFSs representing unique ecosystems in terms of tree flora and environment (Laumonier 1997). The impact of deforestation on individual EFSs has been highly varied and in some cases extreme. We assigned one of five ‘extinction risk categories’ to each EFS based on the percentage of forest lost between 1985 and 2007. Eighty-five percent of all forest loss (10.2 million ha) occurred in the eastern peneplain, western lowland regions and swamps. In 2007, only 29% of forests were protected by conservation areas, only nine of the 38 EFS had more than 50% of their remaining forest cover protected. 38% of remaining forest was “critically endangered”, “endangered” or “vulnerable” EFSs (5 million ha) but only 1 million ha (20%) were protected. Sumatra’s existing network of conservation areas does not adequately represent the island’s ecosystems. Priorities for a new conservation area network can be formulated for integration into Sumatra’s new land use plans at provincial and district level. Decision makers can now use EFSs to locate new conservation areas so they represent and maintain the whole range of the island’s diversity.  相似文献   

18.
Earthquake‐generated tsunamis threaten coastal areas and low‐lying islands with sudden flooding. Although human hazards and infrastructure damage have been well documented for tsunamis in recent decades, the effects on wildlife communities rarely have been quantified. We describe a tsunami that hit the world's largest remaining tropical seabird rookery and estimate the effects of sudden flooding on 23 bird species nesting on Pacific islands more than 3,800 km from the epicenter. We used global positioning systems, tide gauge data, and satellite imagery to quantify characteristics of the Tōhoku earthquake‐generated tsunami (11 March 2011) and its inundation extent across four Hawaiian Islands. We estimated short‐term effects of sudden flooding to bird communities using spatially explicit data from Midway Atoll and Laysan Island, Hawai'i. We describe variation in species vulnerability based on breeding phenology, nesting habitat, and life history traits. The tsunami inundated 21%–100% of each island's area at Midway Atoll and Laysan Island. Procellariformes (albatrosses and petrels) chick and egg losses exceeded 258,500 at Midway Atoll while albatross chick losses at Laysan Island exceeded 21,400. The tsunami struck at night and during the peak of nesting for 14 colonial seabird species. Strongly philopatric Procellariformes were vulnerable to the tsunami. Nonmigratory, endemic, endangered Laysan Teal (Anas laysanensis) were sensitive to ecosystem effects such as habitat changes and carcass‐initiated epizootics of avian botulism, and its populations declined approximately 40% on both atolls post‐tsunami. Catastrophic flooding of Pacific islands occurs periodically not only from tsunamis, but also from storm surge and rainfall; with sea‐level rise, the frequency of sudden flooding events will likely increase. As invasive predators occupy habitat on higher elevation Hawaiian Islands and globally important avian populations are concentrated on low‐lying islands, additional conservation strategies may be warranted to increase resilience of island biodiversity encountering tsunamis and rising sea levels.  相似文献   

19.
The archipelago-like coastal forest of East Africa is one of the highest priority ecosystems for biodiversity conservation worldwide. Here we investigate patterns of species richness and biogeographic distribution among birds, mammals and reptiles of these forests, using distribution data obtained from recently published reviews and information collated by the WWF Eastern Africa Coastal Forest Ecoregion Programme. Birds and mammals species were divided into forest specialists and generalists, and forest specialist reptiles into ‘coastal’ and ‘forest’ endemics. The species richness of birds and generalist mammals increased with area, and is probably a result of area-dependent extinction. Only in birds, however, species richness increased with decreasing isolation, suggesting possible isolation-dependent colonization. Forest diversity, associated to altitudinal range, is important for specialist birds and mammals, whose species richness increased with wider altitudinal range. The number of relict coastal endemic and forest endemic reptiles was higher in forests with wider altitudinal ranges and on relatively higher altitude, respectively. Such forests have probably provided a suitable (and perhaps stable) environment for these species through time, thus increasing their persistence. Parsimony analysis of distributions (PAD) and cluster analyses showed geographical distance and general ecological similarity among forests as a determinant factor in bird distribution patterns, with compositional similarity decreasing with increasing inter-forest distance. Compositional similarity patterns of mammals among the forests did not show a strong geographical correspondence or a significant correlation with inter-forest distance, and those of reptiles were not resolved, with very low similarity levels among forest faunas. Our results suggest that the relative importance (and causal relationship) of forest attributes affecting the distribution of the East African coastal forest vertebrate fauna varies depending on life history traits such as dispersal ability and forest specialization. The groupings in PAD are partly congruent with some of the previous classifications of areas of endemism for this region, supporting the ‘naturalness’ of these regions.  相似文献   

20.
The coastal forests of Kenya are conservation priorities hosting high levels of biodiversity. Monitoring of biodiversity in these forests is therefore necessary to understand and reverse negative trends in good time. Using the Important Bird Area (IBA) monitoring framework, a participatory approach, state (habitat condition), pressure (threats) and response (conservation action) indicators of twelve coastal Kenya forest IBAs were assessed from 2004 to 2011. Trends for these indicators were assessed at six sites for which sufficient data existed: Arabuko‐Sokoke, Dakatcha Woodlands, Gede Ruins, Lower Tana River, Shimba Hills and Taita Hills, and baselines were described for remaining six. Changes were always small, but state deteriorated in Gede, Lower Tana and Shimba Hills, remained the same (unfavourable) in Arabuko‐Sokoke and Dakatcha, and improved in Taita Hills. Pressure reduced in Arabuko‐Sokoke, Dakatcha and Taita Hills, deteriorated in Lower Tana and Shimba Hills and remained the same (medium) in Gede. Response improved in Dakatcha, remained the same (medium) in Shimba Hills, and deteriorated in the rest. As there was an apparent overall deterioration in the forests assessed, improved management of the protected sites and increased conservation action through community engagement around protected areas and within the nonprotected IBAs are recommended.  相似文献   

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