Regeneration dynamics, population structure, and forest composition in some ridge forests of the Western Himalaya, India

Abstract

The present study aimed to analyze the regeneration dynamics, population structure, and forest composition in some ridge forests of the Western Himalaya to elucidate the impact of climate change. The highest species richness (trees, 17; saplings, 16; seedlings, 16) was recorded in mixed Rhododendron arboreum forest. The maximum tree density (737 § 25.93 trees ha ¡1 ; mixed Quercus floribunda); sapling density (5342 § 587.54 saplings ha ¡1 ; mixed Quercus semecarpifolia), and seedling density (71,429 § 26,632.29 seedlings ha ¡1 ; mixed Cedrus deodara) were recorded in forests of higher altitudes. The mean basal cover values in these forests oscillated between 39.21 § 1.53 m 2 ha ¡1 (mixed Quercus leucotrichophora) to 87.65 § 15.45 m 2 ha ¡1 (mixed Abies pindrow). The highest Shannon index value (0.51 § 0.05) and species evenness (0.36 § 0.02) for trees were recorded in mixed Rhododendron arboreum forest. Some species like Betula utilis, Myrica esculenta, Ficus rumphii, Ilex dipyrena, Quercus floribunda, Litsea elongata, Symplocos paniculata, and Abies spectabilis were noticed as new recruiters (recent invaders) in new habitats, which may change the future forest composition. This study revealed that ridge forests of the Bhagirathi catchment area were in transition phase at middle altitudes. Mixed Quercus floribunda forest was observed to be the youngest regenerating forest; however, mixed Abies pindrow forest was the most mature old-growth forest.

Population structure and regeneration status of rhododendrons in temperate mixed broad-leaved forests of western Arunachal Pradesh, India

“…Besides, local factors, soil and stand conditions play substantial role in regeneration dynamics (Gao et al, 2017). Tree species having no regeneration may be due to the availability of enough moisture content of the soil for the germination of seeds also reported by Tiwari, Rana, Krishan, Sharma, and Bhandari (2018). The ericaceous plants at large, especially Rhododendron species, compete with other associated species and sometimes entirely obstruct canopy tree regeneration in temperate forest ecosystems all over the northern hemisphere (Baker & Van Lear, 1998;Clinton & Vose, 1996;Lei, Semones, Walker, Clinton, & Nilsen, 2002;Mallik, 1996;Messier & Kimmins, 1991;Nilsen et al, 2001Nilsen et al, , 1999.…”

Chloroplast microsatellites reveal genetic diversity and population structure in natural populations of Himalayan Cedar (Cedrus deodara (Roxb.) G. Don) in India

“…As expected, owing to the greater degree of isolation, population divergence or isolation is higher for C. deodara (F ST = 0.22), which was higher than that reported for C. atlantica (F ST = 0.107) (Terrab et al, 2006) and P. radiata (Wu et al, 1998), but was lower in comparison to Himalayan Chir pine (P. roxburghii) (F ST = 0.32, Chauhan 2011). The main reason for the high genetic diversity observed in C. deodara may be associated with its long life cycle outcrossing mating system, wind pollination behaviour and high regeneration potential (Mehta et al, 2015;Tiwari et al, 2018). Another factor that has an important bearing is its large geographic distribution range, which had major differences in geography, climate and habitat conditions.Himalayan ridge top ecosystems are considered to be more sensitive to climate change as they are characterized by uniform sunlight exposure, but variation in altitude give birth to climatic differences and subsequent vegetation changes (Tiwari et al, 2018).…”

“…The main reason for the high genetic diversity observed in C. deodara may be associated with its long life cycle outcrossing mating system, wind pollination behaviour and high regeneration potential (Mehta et al, 2015;Tiwari et al, 2018). Another factor that has an important bearing is its large geographic distribution range, which had major differences in geography, climate and habitat conditions.Himalayan ridge top ecosystems are considered to be more sensitive to climate change as they are characterized by uniform sunlight exposure, but variation in altitude give birth to climatic differences and subsequent vegetation changes (Tiwari et al, 2018). Most of the variation in C. deodara lies within the populations as the species is a temperate cross pollinated with wind and gravity-dispersed seeds, this finding may fit with the general observation that woody, perennial and outbreeding species maintain most of their variation within populations.…”

Community Characteristics and Coexistence of Four Medicinally Important Plants in Quercus Leucotrichophora A. Camus Forest of Central Himalaya, India.

“…Ecological communities are structured by complex networks of organisms and species interactions (Pamela et al 2007). The structure and function of Himalayan forest was studied by various workers (Saxena and Singh 1982;Saxena et al 1984;Upreti et al 1985;Singh and Singh 1992;Singh et al 1994;Rathore et al 1997;Khera et al 2001;Ram et al 2004;Kumar and Ram 2005;Hussain et al 2008;Gairola et al 2011;Bargali et al 2015;Singh et al 2016;Tiwari et al 2018;Sati and Bandooni 2018) from time to time. This forest consists the large number of herbaceous species used by the local people for various purposes.…”