Frequent burning in chir pine forests, Uttarakhand, India

Peter Z Fulé,Satish C Garkoti,Rajeev L Semwal

doi:10.1186/s42408-021-00106-3

Peter Z Fulé, Satish C Garkoti + Show 1 more

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https://doi.org/10.1186/s42408-021-00106-3

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Abstract

BackgroundSubtropical coniferous forests of the lesser Himalaya provide critical ecosystem services but fire regimes have received limited scientific attention. We reconstructed fire regimes using tree-ring methods in a chir pine (Pinus roxburghii Sarg.) forest of Uttarakhand, India. We cross-dated tree-ring samples with fire scars from 36 trees at three sites near rural villages between 1535 and 1848 m elevation.ResultsFires were highly frequent (mean fire intervals all <6 yr) but of low severity, so most mature trees of this thick-barked species survived numerous burns. Fire scars occurred primarily in the dormant period to the middle of early wood formation in tree-rings, consistent with fire season records. Despite the high fire frequency, fires were mostly asynchronous among the three sites, indicating a bottom-up pattern of local ignitions. We observed that resin tapping of the pines interacted with surface fire by allowing fire to burn into the wood of some tapped trees and weaken their structural integrity to the point of breakage.ConclusionsOngoing frequent surface fire regimes linked to human land use are prominent disturbance factors in chir pine forests. Given that these forests support substantial human populations and form part of the watershed for many more people, the effects of anthropogenic fire and interactions with resin-tapping merit further investigation at landscape to regional scales. We suggest developing a research network in Himalayan forests as well as more broadly across southeast Asian pine forests to track interacting disturbances and their ecological and social implications.

Highlights

Subtropical coniferous forests of the lesser Himalaya provide critical ecosystem services but fire regimes have received limited scientific attention
The middle elevations of the Himalayan Mountains, home to dense human populations and critical watersheds for far more people, are dominated by chir pine (Pinus roxburghii Sarg.), a species deeply linked to anthropogenic fire disturbance (Singh et al 2016; Sannigrahi et al 2020)
In the western Himalaya, it grows in lesser Himalayan ranges, Siwaliks, and in the valleys of the rivers between 450 and 1800 meters above sea level, occasionally up to 2300 masl (Troup 1921; Singh and Singh 1992), while in eastern India, chir pine seldom grows above 1000 masl

Summary

Introduction

Subtropical coniferous forests of the lesser Himalaya provide critical ecosystem services but fire regimes have received limited scientific attention. We reconstructed fire regimes using tree-ring methods in a chir pine (Pinus roxburghii Sarg.) forest of Uttarakhand, India. The middle elevations of the Himalayan Mountains, home to dense human populations and critical watersheds for far more people, are dominated by chir pine (Pinus roxburghii Sarg.), a species deeply linked to anthropogenic fire disturbance (Singh et al 2016; Sannigrahi et al 2020). Subtropical coniferous forests of the lesser Himalaya provide critical ecosystem services, quantitative assessments of fire regimes and their links with human activity and climate have received limited scientific attention. In the western Himalaya, it grows in lesser Himalayan ranges, Siwaliks, and in the valleys of the rivers between 450 and 1800 meters above sea level (masl), occasionally up to 2300 masl (Troup 1921; Singh and Singh 1992), while in eastern India, chir pine seldom grows above 1000 masl

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