Browsing by Author "Laxmi Goparaju"

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Disturbance Mediated Changes in Litter Turnover and Nutrient Use Efficiency Facilitate Vegetation Shifts in Tropical Dry Ecosystems: Insights From a 10-Year Vegetation Management Study
(John Wiley and Sons Ltd, 2025) R. K. Chaturvedi; Surendra Kumar Pandey; Anshuman K. Tripathi; Laxmi Goparaju; Arun Jyoti NATH; Akhilesh Singh Raghubanshi; Sharda Rani Gupta; Jamuna Sharan Singh
Tropical dry forests and savannas are critical yet understudied ecosystems that regulate global biogeochemical cycles and support biodiversity. However, their functioning is increasingly threatened by anthropogenic disturbances and climate change. Here, we present a decade-long study (2005–2014) examining litterfall dynamics and nutrient cycling across protection gradients (permanently protected [PP], moderately protected [MP], and unprotected [UP] stands) in India's Vindhyan plateau, where forests are transitioning to savannas due to land-use change. Using field measurements, satellite data, and ecological modeling, we quantified how protection status mediates ecosystem processes in these contrasting biomes. We found that protection status overrides biome differences in driving ecosystem function. PP stands maintained 35%–50% higher annual litterfall (6.4 vs. 3.2 Mg ha−1 yr−1) and double the nutrient return rates (2.54 vs. 1.19 Mg ha−1 yr−1) compared to UP stands, facilitated by microclimatic buffering (3°C–5°C cooler soils, 15%–20% higher humidity) and reduced disturbance. Forests exhibited “elastic resilience,” resisting degradation until abrupt collapse under high disturbance, whereas savannas showed “graded resilience,” declining linearly with disturbance intensity. Alarmingly, MP stands displayed limited recovery, suggesting passive protection alone is insufficient for restoration. Disturbances disrupted nutrient cycling, with UP areas showing 20%–25% higher nutrient use efficiency (NUE)—a short-term survival strategy that reduces long-term nutrient availability. Savanna UP sites are projected to lose 30%–40% of litterfall capacity by 2035, risking irreversible degradation. Landsat data revealed a 6.3% decline in forest cover (2002–2014), exacerbating fire-prone feedback loops. Our findings underscore that protection is paramount for maintaining tropical dry ecosystem functions. Forests require fire suppression, while savannas need grazing management. We advocate for landscape-scale conservation integrating protected cores with buffered use zones. This study provides a framework for managing biome-specific resilience in the face of global change, emphasizing urgent, targeted interventions to avert ecosystem collapse. © 2025 John Wiley & Sons Ltd.
Forest fragmentation and its impact on species diversity: An analysis using remote sensing and GIS
(2005) C.S. Jha; Laxmi Goparaju; Anshuman Tripathi; Biswadeep Gharai; A.S. Raghubanshi; J.S. Singh
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. © Springer 2005.
Forest fragmentation impacts on phytodiversity - An analysis using remote sensing and GIS
(2005) Laxmi Goparaju; Anshuman Tripathi; C.S. Jha
The present study deals with the forest fragmentation of Vindhyan highlands in the Indian dry tropical forests. The fragmentation scenario has been quantified using remote sensing data and GIS techniques. The remotely sensed data-derived vegetation map was an input to the fragmentation analysis. Transects were laid to inventory along different forest patch sizes of various communities to study the biodiversity levels. It was observed that with changing fragment, there is change in biodiversity levels. Hence, patch size might play an important role in the regulation of biodiversity levels. This information may provide an insight into the conservation strategy formulation for the fragmented dry tropical area. The analysis has brought out that biodiversity levels are different in various fragments of different sizes. Small fragments are similar to each other in terms of species composition; similar is the case with large fragments in general. It was also found that the small and large fragments are dissimilar in terms of species composition. The diversity levels among the fragments of similar size class varied across the anthropogenic gradient. Analysis of species richness, diversity indices has helped in studying the patterns/levels of biodiversity in different fragment size classes along different levels of anthropogenic pressure. The merits of conserving the small and large fragments have been discussed.
Temporal dynamics of above ground biomass of Kaimoor Wildlife Sanctuary, Uttar Pradesh, India: conjunctive use of field and Landsat data
(Springer Nature, 2021) Laxmi Goparaju; Rangaswamy Madugundu; Firoz Ahmad; Debadityo Sinha; Jamuna Sharan Singh
The present study assesses the temporal dynamics of above ground biomass (AGB) in Kaimoor Wildlife Sanctuary (KWS), Uttar Pradesh, India using series of Landsat data for the years 1989, 2000, 2010 and 2018. The satellite images were preprocessed for surface reflectance, and subsequently we computed Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), and Enhanced Vegetation Index (EVI). A forest density map was generated by slicing the computed NDVI and this was used as a basis for sampling strategy. A total of 30 sampling locations were randomly identified. Plot size of 30 m × 30 m was established. Tree species were enumerated at each plot and the girth at breast height and tree height measurements were recorded for the year 2018. Tree and plot level AGB (i.e. AGBF, t ha−1) was computed by multiplying the tree volume and specific gravity of wood. AGB (i.e. AGBP) prediction models were developed as linear regression equations for the year 2018 by assessing the vegetation indices and the AGBF. The significant AGBP models (R2 = 0.94; P = 0.0001) were applied for all study years after the data correction among the Landsat sensor series. The AGBP was over estimated (22.67 t ha−1; 7.75%) compared to AGBF (t ha−1). Moreover, EVI (R2 = 0.90) was found to be a better predictor for AGB compared to NDVI (R2 = 0.69) or SAVI (R2 = 0.77). The AGBP of KWS ranged between 289 ± 36 (in 1989) and 292 ± 40 (in 2018) with an average decadal positive change of 1.06%. © 2021, Indian National Science Academy.
Variations in the plasticity of functional traits indicate the differential impacts of abiotic and biotic factors on the structure and growth of trees in tropical dry forest fragments
(Frontiers Media SA, 2023) Ravi Kant Chaturvedi; Santosh Kumar Pandey; Anshuman Tripathi; Laxmi Goparaju; Akhilesh Singh Raghubanshi; J.S. Singh
Abiotic and biotic factors have considerable impact on the plasticity of plant functional traits, which influences forest structure and productivity; however, their inter-relationships have not been quantified for fragmented tropical dry forest (TDF) ecosystems. We asked the following questions: (1) what are the variations in the plasticity of functional traits due to soil moisture availability in TDF fragments? (2) what are the roles of soil nutrients and forest disturbances in influencing variations in the plasticity of functional traits in the TDF fragments? and (3) how do the variations in the plasticity of functional traits influence the structure and productivity of TDF fragments? Based on linear mixed-effects results, we observed significant variations among tree species for soil moisture content (SMC) under the canopy and selected functional traits across forest fragments. We categorized tree species across fragments by principal component analysis (PCA) and hierarchical clustering on principal components (HCPC) analyses into three functional types, viz., low wood density high deciduous (LWHD), high wood density medium deciduous (HWMD), and high wood density low deciduous (HWLD). Assemblage of functional traits suggested that the LWHD functional type exhibits a drought-avoiding strategy, whereas HWMD and HWLD adopt a drought-tolerant strategy. Our study showed that the variations in functional trait plasticity and the structural attributes of trees in the three functional types exhibit contrasting affinity with SMC, soil nutrients, and disturbances, although the LWHD functional type was comparatively more influenced by soil resources and disturbances compared to HWMD and HWLD along the declining SMC and edge distance gradients. Plasticity in functional traits for the LWHD functional type exhibited greater variations in traits associated with the conservation of water and resources, whereas for HWMD and HWLD, the traits exhibiting greater plasticity were linked with higher productivity and water transport. The cumulative influence of SMC, disturbances, and functional trait variations was also visible in the relative abundance of functional types in large and small sized fragments. Our analysis further revealed the critical differences in the responses of functional trait plasticity of the coexisting tree species in TDF, which suggests that important deciduous endemic species with drought-avoiding strategies might be prone to strategic exclusion under expected rises in anthropogenic disturbances, habitat fragmentation, and resource limitations. Copyright © 2024 Chaturvedi, Pandey, Tripathi, Goparaju, Raghubanshi and Singh.