Tropical forest structure and diversity in relation to altitude and disturbance in a Biosphere Reserve in central India

Abstract

Questions: Is species diversity affected in protected areas where human activities are permitted or tolerated? On plots of a fixed size, does stem density alone predict number of species? Are differences in density related to disturbance and altitude? Location: Achanakmar‐Amarkantak Biosphere Reserve, central India. Methods: 42 sites, each with three replicate 10‐m radius plots, were examined. All trees (≥ 30 cm GBH) in each plot were measured for girth at breast height. α‐diversity, species richness and evenness were calculated for each site. The sites were ordinated by Nonmetric Multidimensional Scaling (NMS) using relative importance values of component species. Correspondence Analysis was used to broadly delineate communities. Anthropogenic disturbances were recorded in terms of percentage of trees lopped, scale of lopping, number of domestic livestock dung piles and foot trails (both livestock and people) for each plot. Results: The NMS analysis exhibited a near linear arrangement of sites with no evidence of discrete vegetation zones. NMS axes were significantly related to altitude and disturbance scores. With increasing elevation, basal area increased but number of species, α‐diversity and its components declined monotonically. The number of species and indices of species diversity were positively associated with tree lopping and also with total disturbance. Number of species was controlled by stem density only in plots not dominated by Shorea robusta. Conclusions: Recent levels of human disturbance are associated with higher species diversity in this biosphere reserve. There is some evidence that stands at all altitudes follow the same successional pattern to dominance by Shorea, a successional pattern that also results in decreased diversity without disturbance.

Carbon stocks of Hanang forest, Tanzania: An implication for climate mitigation

“…However the relationship between herbaceous carbon as well as soil organic carbon and altitude for three soil layers was not statistically significant (Table 6). In a similar study conducted in AchanakmarAmar-Kantak Biosphere Reserve in India, significant relationships against altitude were only observed for basal area and stem density, respectively (Sahu et al, 2008). In a study conducted in Southern Appalachian spruce-fir forest, soil carbon did not show a trend with altitude, likewise the carbon dynamics did not show a consistent pattern with altitude (Tewksbury and Miegroet, 2007).…”

Variabilité Structurale Des Peuplements D’arbres En Forêt De Montagne Du Parc National De Kahuzi-Biega Et Ses Environs, RD. Congo

“…Dans le Rift albertin, Eilu et al, (2004), notent une surface terrière de 14,5 à 45 m²/ha en Ouganda, alors que Lovett et al, (2006) précisent que la valeur de la surface terrière peut aller jusqu'à 70 m²/ha en Tanzanie selon les formations végétales tout en précisant que la relation densité et surface terrière est positive. Pour les montagnes de l'Inde, Sahu et al, (2008) déterminent la surface terrière variant entre 7 et 74 m²/ha et qui augmente avec l'altitude mais pas avec la densité. Dans les montagnes en Ethiopie, Gurmessa et al, (2012) trouvent une surface terrière de 51m²/ha et précisent que les classes de diamètre de 10 à 30 cm contribuent faiblement dans la valeur de la surface terrière.…”

“…Hormis ces facteurs clés, la structure d'un écosystème peut être, aussi influée par des facteurs naturels comme la présence ou l'absence de lianes envahissantes (Masumbuko et al, 2012), l'intensité de la perturbation de l'écosystème favorisant des trouées (Huang et al 2003;Sahu et al, 2008;Boyemba, 2011), ou des vents violents (Masumbuko et al, 2012 ;Mangambu et al, 2015). De ces faits, l'analyse de la structure de la végétation et sa variabilité sont des indicateurs pour tester la théorie écologique du fonctionnement de l'écosystème (Ostertag et al, 2014) et comprendre sa dynamique (Bogaert et Mahamane, 2005).…”

Effects of wildfires on flora, fauna and physico-chemical properties of soil-An overview

“…The forest fire in addition to the intermittent canopy structure provides favorable habitats for the development and high abundance. The potential of lianas and shrubs to regenerate well naturally where the fire events and/or higher anthropogenic disturbances are common (Rodgers et al, 1986;Kumar and Thakur, 2008;Sahu et al, 2008;Mishra et al, 2008;Jhariya and Oraon, 2012c). Various reasons are reported by different workers which supports to lianas and shrubs growth like fire derived nutrient deposition (Asner et al, 1997;Dawson et al, 2002;Chen et al, 2010;Jhariya, 2010), availability of tree-fall gaps resulted from the natural and/or anthropogenic disturbance (Putz, 1983 Gianoli et al, 2010;Schnitzer et al, 2012) because fire causing damage to sensitive species which resulted killing of the trees and new growing ones (Jhariya, 2013).…”