Population Dynamics of Juniperus macropoda Bossier Forest Ecosystem in Relation to Soil Physico-Chemical Characteristics in the Cold Desert of North-Western Himalaya

Abstract

Juniperus macropoda is the only tree species of a cold desert ecosystem that is experiencing high anthropogenic pressure and has a poor regeneration status due to harsh environmental conditions. Due to the limited distribution of Juniperus macropoda in this region, the species have remained largely unexplored in terms of understanding the distribution pattern along the elevation and soil fertility gradients. Therefore, the current research was carried out along the elevational gradient, starting from the base line at 3000 m above sea level (m asl) asl with an elevational plot distance of 180 m. The study revealed that the average density of J. macropoda declined gradually from the first elevation range, i.e., 3000–3180 m asl onward, and extended up to the elevation range of 3900–4080 m asl. However, the average seedling and sapling densities were highest at mid-elevation and extended up to an elevation range of 4080–4260 m asl. The J. macropoda population formed a reverse J-shaped structure only up to 3540–3720 m asl. The maximum total biomass and carbon density were recorded in the lowest elevational range, and decreased subsequently. The primary soil nutrients under study decreased sharply along the elevational gradient. Seedling, sapling and tree distributions had a significantly positive relationship (p < 0.05) with available N, P, K, SOC, silt and clay contents and were negatively correlated (p < 0.05) with sand contents. The outcome of the study will form the basis for devising a plan for the management and conservation of J. macropoda forests.

Tree species diversity, distribution and population structure of Fraxinus xanthoxyloides in Western Himalayas

“…The diverse topography and elevation range in the mountainous forest ecosystem had a signi cant impact on the environmental microclimate (Qanbari, and Jamali, 2015), vegetation cover, and soil properties over a relatively short distance, frequently with sudden transitions (ecotone) in the vegetation sequences. The most important environmental elements that may contribute to the decline in growth and developmental features along an altitudinal gradient include temperature, light intensity, soil moisture, and fertility status in the alpine ecosystem (Kumar et al 2022b). Due to changes in abiotic variables such as climate, soil, and temperature as well as the altitudinal gradient, especially in undisturbed mountain ecosystems, the altitudinal gradient is thought to be a signi cant in uence impacting species composition and structure (Rawat 2022).…”

“…Similarly,Rajwar et al (1999) suggested the climatic and biotic stress in uence the regeneration potential of species and pointed out that the proportionate conversion of seedlings into sapling stage affected by biotic disturbances and competition for space and nutrients. Furthermore,Kumar et al (2022b) revealed that the Juniperus macropoda tree's growth and development qualities, such as crown height, crown breadth, crown length, and stand characteristics, were highest at lower elevation ranges and considerably decreased along the gradient of elevation. Fraxinus xanthoxyloides, as an excellent source of fuelwood, timber, and fodder, another potential explanation for the reduced conversion rate of seedlings into saplings could be the trampling and grazing by both domesticated and wild animals.…”