Variation in tree biomass and carbon stocks with respect to altitudinal gradient in the Himalayan forests of Northern Pakistan

Abstract

Forest ecosystems play a significant role in biomass, carbon stocks and the global carbon cycle. They
show variation along with the elevation gradient. This study was conducted to evaluate the variation in tree biomass
and carbon stocks with respect to the elevation in the Himalayan forests of Northern Pakistan. The study area was
categorized into four elevation classes namely ELV-1 (500 m – 1000 m), ELV-2 (1000 m – 1500 m), ELV-3 (1500
m – 2000 m), ELV-4 (2000 m – 2500 m). Our results showed that the stem density at ELV-1 was found to be the
highest such as 761.18 trees ha-1 than that of 423.82 trees ha-1
at ELV-2, 428.82 trees ha-1
at ELV-3 and 457.82 trees
ha-1
at ELV-4, respectively. However, the biomass and stored carbon contents were found to be the highest at ELV-4
such as 474.08 Mg ha-1 and 279.89 Mg C ha-1
, respectively as compared to ELV-3, ELV-2 and ELV-1 (lower
elevations). Similarly, the basal area (BA) was recorded to be the highest at ELV-4 such as 76.41 m2
ha-1
, while at
ELV-1 it was found to be the lowest with 13.1 m2
ha-1
. A decreasing trend was noticed in the density of the study
area with an increase in altitude. The results highlighted the variation in density, BA, stem volume, tree biomass and
tree carbon with respect to elevations. This study will provide scientific information to researchers about the role of
altitude in the studied parameters, which will help the foresters in formulating the forest management policies.