The process of forest fragmentation, a common phenomenon occurring in tropical forests, not only results into continuously forest getting fragmented but also brings about several physical and biological changes in the environment of forests. Consequently, there is a loss of biodiversity due to change in habitat conditions. These remnant fragments provide the last hope for biodiversity conservation. The present study deals with the impact of decreasing patch size of a fragmented forest on the diversity of the tropical dry deciduous forests in Vindhyan highlands, India. There is considerable change in the vegetation cover of this region owing to rapid industrialization and urbanization, which has also contributed to forest fragmentation. In the present study, remotely sensed data has been used to describe the changes brought about in vegetated areas over a period of 10 years as a result of fragmentation and its impact on biodiversity was assessed. Further, in order to assess the loss of species with respect to the reduction in patch size, species area curves for various change areas were analysed. It was observed that the rate of decrease in the number of species is faster in the case of negative change areas as compared to the positive change areas of the region. Various diversity indices also support this observation. Such an analysis would help in formulating appropriate conservation measures for the region.

Forest fragmentation and its impact on species diversity: an analysis using remote sensing and GIS

Effect of disturbance, habitat fragmentation and exotic plant species invasion on plant diversity is documented for the dry deciduous forests of India’s Vindhyan highlands. Plant communities were identified with the help of satellite imagery and ground data, and community wise diversity was estimated. Analysis of landscape matrices using satellite images and GIS tools showed deforestation of smaller fragments, and fragmentation and degradation of larger ones. Fragments of smaller size had lesser number of plant communities compared to larger fragments. Generally large size fragments were species rich and more diverse as compared to smaller fragments. Lagestoemia-Acacia-Lannea community was richest for both tree and herb strata, whereas Shorea-Buchanania community was the richest when all vascular flora were considered. The study indicates that species rich communities of the dry tropical forests are not only being reduced in area but they are also becoming species poor and less diverse due to rapid deforestation and forest fragmentation. The communities most vulnerable to alien invasive plants were Acacia-Terminalia, Terminalia-Shorea and Hardwickia-Acacia. Ecological implications of plant invasion are discussed and conservation measures suggested. Resumen: Se documenta el efecto del disturbio, la fragmentacion del habitat y la invasion de especies vegetales exoticas sobre la diversidad vegetal para el bosque seco caducifolio de las tierras altas de Vindhyan, India. Las comunidades vegetales fueron identificadas por medio de imagenes de satelite y datos de campo, y se estimo la diversidad de las comunidades. El analisis de las matrices de paisaje que usaron imagenes satelitales y herramientas de SIG mostraron la deforestacion de los fragmentos pequenos, y la fragmentacion y degradacion de los de mayor tamano. Los fragmentos pequenos tuvieron un menor numero de comunidades vegetales que los fragmentos mayores. En general, los fragmentos grandes fueron ricos en especies y mas diversos en comparacion con los fragmentos pequenos. La comunidad de Lagestoemia-Acacia-Lannea fue la mas rica tanto para arboles como para el estrato herbaceo, mientras que la comunidad de Shorea-Buchanania fue la mas rica cuando se considero a toda la flora vascular. El estudio indica que las comunidades ricas en especies del bosque tropical seco no solamente se estan reduciendo en area, sino que ademas se estan haciendo menos ricas en especies y menos diversas debido a la rapida deforestacion y fragmentacion del bosque. Las comunidades mas vulnerables a las plantas invasoras exoticas fueron Acacia-Terminalia, Terminalia-Shorea y Hardwickia-Acacia. Se discuten las implicaciones ecologicas de la invasion de plantas y se sugieren medidas para la conservacion. Resumo: O efeito das perturbacoes, fragmentacao do habitat e invasao de plantas exoticas esta documentado para a floresta seca decidua das terras altas de Vindhyan na India. As * Corresponding Author; e-mail: raghubansh@gmail.com 58 PLANT DIVERSITY IN VINDHYAN FORESTS comunidades vegetais foram identificadas com a ajuda de imagens de satelite e dados de campo, e a diversidade alargada foi estimada. As analises das matrizes de paisagem usando imagens de satelite e ferramentas GIS mostrou a desflorestacao de pequenos fragmentos, e fragmentacao e degradacao das maiores. Os fragmentos de menor dimensao apresentavam menor numero de comunidades de plantas quando comparadas com os fragmentos maiores. Geralmente os fragmentos de maior dimensao eram rios em especies e mais diversos em comparacao com os menores. A comunidade Lagestoemia-Acacia-Lannea era a mais rica quer no numero de arvores e no estrato herbaceo, enquanto que a comunidade Shorea-Buchanania era mais rica quando toda a flora vascular era considerada. O estudo indica que as comunidades ricas em especies das florestas secas tropicais nao so vem a sua area sendo reduzida mas se vem tornando mais pobres em especies e menos diversas devido a rapida desflorestacao e a fragmentacao da floresta. As comunidades mais vulneraveis a invasao de especies exoticas invasivas eram a AcaciaTerminalia, Terminalia-Shorea e Hardwickia-Acacia. As implicacoes ecologicas da invasao de plantas sao discutidas e sugeridas medidas de conservacao.

Effect of disturbance, habitat fragmentation and alien invasive plants on floral diversity in dry tropical forests of Vindhyan highland: a review.

Deforestation and fragmentation are important concerns in managing and conserving tropical forests and have global significance. In the Indian context, in the last one century, the forests have undergone significant changes due to several policies undertaken by government as well as increased population pressure. The present study has brought out spatiotemporal changes in forest cover and variation in forest type in the state of Odisha (Orissa), India, during the last 75 years period. The mapping for the period of 1924–1935, 1975, 1985, 1995 and 2010 indicates that the forest cover accounts for 81,785.6 km2 (52.5 %), 56,661.1 km2 (36.4 %), 51,642.3 km2 (33.2 %), 49,773 km2 (32 %) and 48,669.4 km2 (31.3 %) of the study area, respectively. The study found the net forest cover decline as 40.5 % of the total forest and mean annual rate of deforestation as 0.69 % year−1 during 1935 to 2010. There is a decline in annual rate of deforestation during 1995 to 2010 which was estimated as 0.15 %. Forest type-wise quantitative loss of forest cover reveals large scale deforestation of dry deciduous forests. The landscape analysis shows that the number of forest patches (per 1,000) are 2.463 in 1935, 10.390 in 1975, 11.899 in 1985, 12.193 in 1995 and 15.102 in 2010, which indicates high anthropogenic pressure on the forests. The mean patch size (km2) of forest decreased from 33.2 in 1935 to 5.5 in 1975 and reached to 3.2 by 2010. The study demonstrated that monitoring of long term forest changes, quantitative loss of forest types and landscape metrics provides critical inputs for management of forest resources.

Assessment and monitoring of long-term forest cover changes in Odisha, India using remote sensing and GIS

The primary source: tropical forests and our future

Lantana camara, a noxious weed, has been expanding and now established in many regions of the world, including India. As it poses major threats to ecosystem, it has been in the focus of control attempts. For the purpose of this research, various characteristics of Lantana camara are discussed and techniques to combat its invasion in India have been studied. Results reveal that species have become menace and expanding its range. Present research also suggest that more than 80% of studies focus on its impact, use, toxicity, and its therapeutic uses only. It thus comes out clear, that research focusing on path and progression of Lantana camara, besides knowing its ecology, is the need of the hour. Information of this kind, as presented in this research, is critically needed to plan- out a befitting response to protect the ecosystems at a matching scale; else it may be impossible to make any headway towards meaningful control with small, scattered and sporadic attempts.

http://www.ijsrp.org/research-paper-1013/ijsrp-p2207.pdf

A review of Lantana camara studies in India

Forest is a major resource and plays a vital role in maintaining the ecological balance and environmental setup. Over utilization of forest resource has resulted in its depletion. The changes in tropical forest cover are matter of global concern due to its ability of promoting role in carbon cycle. This renewable resource continues to decrease at accelerated rate. Accurate and timely information in regular interval on the distribution of natural resources on earth is of top priority for understanding dynamics of the human induced land cover/land use accelerated changes. This information can be further utilized in understanding biophysical processes of the earth. In India and the other developing countries it is mostly been lost for the agricultural practices. Aerospace technology is a potential means of collecting information about natural resources including forests at any desired time. The technology is considered important to revise or update available information. The present paper addresses the status of tropical forest and requirements for its monitoring and assessment. It discusses the potential of the remote sensing technology for managing the forests, in general and sustaining the pace of development in this technology. It focuses the technology trends and techniques for tropical forest assessment at different scale and levels.

P. K. Joshi

Papers

Tropical forest resource assessment and monitoring