The study, published in Discover Forests, represents one of the few genuine long-term reassessments of biomass and carbon storage ever conducted in the tropical dry forests of Central India. A team led by Pranab Kumar Pati of Dr. Harisingh Gour Vishwavidyalaya in Sagar returned in 2025 to the same six forest communities first surveyed in 2001, using the same quadrat-based field protocols to make the two datasets directly comparable. The baseline came from earlier vegetation work in the Pathariya Hills, a rugged outcrop of the lower Vindhyan range built on Deccan Trap basalt, where steep slopes, gullies, ravines and plateaus create a mosaic of soils and habitats that support strikingly different forest assemblages within a small area.

The headline structural finding is stark. Tree density fell from 2,727 individuals per hectare in 2001-02 to 1,347 per hectare in 2025, a statistically significant decline with a large effect size. Yet basal area, the cross-sectional area of all tree stems measured at breast height, barely changed, slipping only marginally from 20.41 to 19.83 square metres per hectare. The explanation lies in the size distribution of the survivors. Mean basal area per tree nearly doubled across the landscape, from 0.0075 to 0.0147 square metres, indicating that the trees that disappeared were overwhelmingly small and young, while the remaining large individuals kept growing and now carry a disproportionate share of the stand’s wood.

That demographic shift is the quiet alarm buried in the data. Dense stands of many small stems have given way to forests dominated by fewer, larger trees, a pattern the authors attribute to selective removal of small and medium individuals and chronic suppression of regeneration under sustained disturbance and grazing. If younger cohorts continue to be depleted, the large residual trees that currently prop up the forest’s basal area, biomass and carbon stocks will eventually age out without replacement, opening canopy gaps, reducing productivity and undermining the ecosystem’s resilience. The structural stability visible today may simply be a lag effect, a demographic imbalance waiting to surface.

The biomass numbers themselves reveal the study’s central paradox. Total biomass across the complex rose from 116.25 to 120.18 megagrams per hectare, a net landscape-level gain of only 3.2 percent that was not statistically significant. But that modest average is the arithmetic of two diverging worlds. At relatively protected Site 1, biomass surged 81 percent, from 28.71 to 151.63 megagrams per hectare, and Site 2 gained 42 percent. At heavily disturbed Site 3, biomass collapsed by half, from 100.87 to 49.57 megagrams per hectare, and Site 6 lost 52 percent, falling from 169.22 to 80.71 megagrams per hectare. Site 4 remained essentially flat. The forest complex is not one carbon store but a patchwork of sinks and sources, and the average erases the difference.

The driver of that divergence is disturbance intensity. Sites 3 and 6 face severe ongoing pressure from logging, lopping, fuelwood extraction, recurrent fire and livestock grazing, with commercially valuable species such as Anogeissus latifolia, Tectona grandis and Santalum album regularly felled illegally. The remaining sites, shielded by stricter Forest Department protection, show no comparable stress. The study’s correlation analysis reinforces the mechanism: basal area was strongly and positively related to total biomass, while stem density showed no significant relationship, confirming that large trees, not tree counts, govern carbon storage in these forests. Where mature individuals are selectively removed, the carbon goes with them.

Species-level analysis adds another layer of concern. Tectona grandis, the teak that characterizes Central Indian dry deciduous forests, contributed the largest biomass gain at 23.09 megagrams per hectare, a recovery the authors link to the gradual strengthening of protection after the extensive teak felling of the 1950s. Butea monosperma, a disturbance-tolerant, fire-resistant, light-demanding species with low palatability to livestock, added 8.23 megagrams per hectare and now dominates the most degraded sites. That dominance is not good news. It signals ecological filtering under chronic disturbance, canopy opening and the progressive loss of shade-tolerant, late-successional taxa, a trajectory toward biotic homogenization in which a handful of resilient species replace a diverse community.

Meanwhile, several ecologically important native species lost ground. Albizia lebbeck, Bridelia retusa, Diospyros melanoxylon, Elaeodendron glaucum, Lannea coromandelica and Madhuca indica all declined in biomass contribution, with losses ranging from roughly 3.8 to 7.6 megagrams per hectare. The authors caution that high biomass in stands increasingly dominated by Butea monosperma should not be mistaken for ecosystem health. Carbon stocks can be partially maintained even as species diversity, functional trait breadth and adaptive capacity erode, leaving the forest less productive, less stable and less able to sequester carbon reliably under future climatic variability.

Methodologically, the study is a model of careful, non-destructive estimation. Aboveground biomass was calculated with the Chave allometric model for tropical dry forests, incorporating field-measured diameters and species-specific wood specific gravity values drawn from an Indian inventory, while belowground biomass followed the Cairns equation for adults and IPCC conversion factors for juveniles. Carbon stocks were derived by applying the standard IPCC carbon fraction of 0.5 to combined above- and belowground biomass. Because the temporal data did not consistently meet assumptions of normality and sample sizes were constrained by the original survey design, the team used the Mann-Whitney U test for temporal comparisons and quantified effect sizes with Hedges’ g, an appropriately conservative approach they acknowledge should be corroborated by larger future samples.

The findings carry clear implications for climate policy and forest management in a country where tropical dry forests cover nearly 42 percent of the total forest area and almost 89 percent of Madhya Pradesh’s forest cover. The authors call for stricter disturbance regulation at the most degraded sites, enrichment planting and assisted regeneration of declining native species, community participation in protection, and the establishment of permanently marked monitoring plots with high-precision georeferencing, which would remove the relocation uncertainties inherent in resampling historical, unmarked quadrats. Quantitative disturbance indices combining field measurements with remote sensing would further sharpen the link between specific pressures and carbon outcomes. The broader lesson is one that resonates far beyond the Pathariya Hills: headline carbon numbers can mask ecological degradation, and protecting the large trees of today means little without safeguarding the recruits that must become tomorrow’s canopy. In the accounting of forest carbon, what survives matters even more than what is stored.

Subject of Research: Long-term changes in forest biomass and carbon stocks in a tropical dry deciduous forest in Central India

Article Title: Temporal dynamics of biomass and carbon stocks over twenty five years in the Pathariya forest complex of Central India

Article References: Pati, P. K., Rajput, N. S., Kaushik, P., Khan, M. L., & Khare, P. K. (2026). Temporal dynamics of biomass and carbon stocks over twenty five years in the Pathariya forest complex of Central India. Discover Forests, 2(1), Article 70. https://doi.org/10.1007/s44415-026-00133-5

Image Credits: AI Generated

DOI: 10.1007/s44415-026-00133-5

Keywords: forest biomass, carbon stocks, tropical dry deciduous forest, Central India, anthropogenic disturbance, tree density, basal area, forest degradation, Butea monosperma, Tectona grandis, carbon sequestration, long-term monitoring