Forest degradation impacts on carbon stocks, tree density and regeneration status in banj oak forests of Central Himalaya

Abstract

The oak forests of the Himalaya are an important repository of carbon. Forest degradation, in terms of loss in biomass and carbon, is a more pressing problem than loss of forest area in the Himalaya. The altitudinal gradient between 1,000 m and 2,200 m is dominated by chir pine and banj oak forest. As a result of small-scale chronic disturbances the structure and function of banj oak forest is rapidly changing, leaving few pristine patches. Forty permanent plots of 400 m 2 in four disturbance categories of Central Himalayas (1,400 m-2,300 m asl) were studied over 3 years (2015, 2016 and 2017) to understand the impact of disturbance on banj oak forests. The study indicates that tree biomass declined by 62% from undisturbed to degraded forests, carbon sequestration rate declined by 73% and was maximum for Moderately disturbed-A forests, total soil carbon dropped by 79% and mycorrhizal sporocarps declined by 78% from undisturbed to degraded forests. There was an overall decline in tree density by 56% from undisturbed forests to degraded forests. In degraded forests, the invasion of pine, a species tolerant of disturbance, helps in maintaining the forest status but the population structure changes and significant decline in carbon sequestration rate and total biomass stocks (above ground biomass and below ground biomass) was observed. The study indicates that moderate level disturbance promotes better carbon sequestration rates, tree density and the survival of seedlings.

Long-Term Impact of Transhumance Pastoralism and Associated Disturbances in High-Altitude Forests of Indian Western Himalaya

“…In our study, the highest values (Mgha −1 ) of AGBD, BGBD, and TBD were obtained for ANS forest type. Previous works also report similar trend in biomass parameters in Himalayan forests [63][64][65]. NNS forest type showed 2.1 times more average carbon loss (29.59 ± 4.18 MgCha −1 ; mean ± SD) than ANS forest type (13.64 ± 3.32 MgCha −1 ).…”

“…NNS forest type had the least stem density and basal area as compared to ANS forest type. Similar relatively higher values were reported at less disturbed sites by various workers in other parts of the Himalayas, revealing the negative impact of anthropogenic stresses on the forest structural attributes [65,70,71]. Due to the limited livelihood options, the nomadic people living in the vicinity of the high-altitude fir forests depend heavily upon coniferous tree species for timber, fuelwood, and leaf litter.…”

Dynamics of ecosystem carbon stocks in a chronosequence of nitrogen‐fixing Nepalese alder (Alnus nepalensis D. Don.) forest stands in the central Himalayas

“…Himalayan forests play a significant role in the world carbon cycle because of their enormous carbon stocks and future vulnerability to climate change, as the region is going to warm at greater rates than that of the global average (Pandey, Arunachalam, Thadani, & Singh, 2020; Ranjan, 2018; Singh, Pandey, & Singh, 2019). In the central Himalaya, below 2,500 m elevations, A. nepalensis , being a pioneer tree species, occupies the habitats after‐disruption (landslides/landslips) (Joshi & Garkoti, 2020; Rana, Rana, Shrestha, Sujakhu, & Ranjitkar, 2018; Sharma et al, 1998).…”

Forest structures and carbon stocks of community forests with different forest management in Maha Sarakham Province, Thailand

“…They play a very important role in regional and global carbon cycles (Mitchard 2018) and global mitigation of climate variability (Zhao et al 2022). Carbon from the atmosphere is retained in above-belowground biomass such as stems, branches, leaves and roots (Meeussen et al 2021;Ramachandra and Bharath 2019) and dead organic matter including woody debris and surface litter (Zhu et al 2017) through the photosynthesis process (Pandey et al 2019). It is also accumulated in soil organic matter (Ramachandra and Bharath 2020) through the decomposition of plant litter and fine-root biomass (Świątek and Pietrzykowski 2022).…”