Fine root dynamics and associated nutrient flux in Sal dominated forest ecosystems of Central Himalaya, India

Abstract

The belowground systems of trees have a major role in forest functioning through absorption of water and nutrient cycling. This study deals with the fine root dynamics including fine root biomass, necromass, production, turnover, and nutrient return in transitional Sal (Shorea robusta Gaertn. f.) dominated sub-tropical forest ecosystems of Central Himalaya, India. Four sites namely, Site-1 (Kaladhungi), Site-2 (Fatehpur), Site-3 (Ranibagh), Site-4 (Amritpur) were selected in Sal forest within an elevational range between 405 and 580 m above sea level. The dominant and associated co-dominant species were selected from each site for the estimation of fine root dynamics by using sequential core and ingrowth core methods. The results revealed that the fine root biomass, necromass, and production were significantly (p < 0.05) affected by location, seasons, and soil properties. The fine root biomass and production decreased with increasing soil depth and also influenced by stand characteristics including tree density and basal area. The rainy season was most productive with maximum fine root biomass (507.37 kg ha–1) as well as fine root production (600.26 kg ha–1 season–1) in the dominant tree species S. robusta. Among the associated co-dominant tree species highest fine root biomass (330.48 kg ha–1) and fine root production (410.04 kg ha–1 season–1) was reported for Tectona grandis L. during the rainy season, while lowest fine root biomass (126.72 kg ha–1) and fine root production (195.59 kg ha–1 season–1) in the Glochidion velutinum Wight tree species during the winter season. Annual fine root production ranged from 460.26 to 1583.55 kg ha–1 yr –1, while turnover rate varied from 1.37 to 4.45 yr–1 across all the studied sites. The fine roots added carbon input of 154.38 to 564.20 kg ha–1 yr–1 and nitrogen input of 6.58 to 24.34 kg ha–1 yr–1 to the soil through annual flux. The study improves our understanding on fine root parameters under the influence of sites, soils and seasonal and spatial variation. The return of nutrients to the soil through fluxes from the roots illustrates the role of fine roots in carbon and nitrogen cycling of the forests and this potential can be harnessed to assess the long-term carbon and nitrogen pool estimations in forests and to plan and manage the forest ecosystems.

Effects of Thinning Intensity on Litterfall Production, Soil Chemical Properties, and Fine Root Distribution in Pinus koraiensis Plantation in Republic of Korea

“…The pattern in the vertical distribution of fine root biomass and necromass observed in P. koraiensis plantation can be ascribed to soil conditions, particularly water and nutrient contents in different soil layers [47,48], as reported in previous studies [49][50][51]. Specifically, as soil depth increases, soil water and nutrient resources become more limited, which can lead to a decrease in fine root production and, consequently, a decrease in fine root necromass buildup in a particular soil depth.…”

Pattern of plant biomass and carbon stock along different elevational forests in eastern Nepal

“…nutrient supply due to their high turnover rate as compared to those with 2-5 mm diameter (Gautam & Mandal, 2016). The maximum fine-root biomass observed in the Murchungi site (see Figure 5 above) could be attributed to a potentially lower turnover rate, possibly associated with specific species characteristics (Pandey et al, 2023;Raich et al, 2009). The fine-root biomass displayed an increasing trend up to the Murchungi site, followed by a decrease with increase in elevation beyond this point.…”

Plant diversity drives soil carbon sequestration: evidence from 150 years of vegetation restoration in the temperate zone

“…In recent decades, the increasing emissions of CO 2 -based greenhouse gases in the atmosphere (CO 2 emissions have increased from 280 ppm in the pre-industrial era to 400 ppm today) have led to a series of environmental problems, such as global warming, sea level rise, and increase in extreme weather events, which seriously threaten the sustainable development of natural ecosystems and socio-economic systems ( Zhang et al., 2011 ; Ramachandra and Bharath, 2020 ). Vegetation restoration is often used to increase soil organic carbon (SOC) storage and sequestration to reduce CO 2 emissions and restore ecosystem functions ( Zhao et al., 2015 ; Pandey et al., 2023 ; Shahi et al., 2023 ). Such restoration promotes the accumulation of SOC, making SOC the largest component of the terrestrial SOC pool, which is consequently two to three times greater than the vegetation carbon pool and plays a crucial role in regulating global warming ( Davidson et al., 2000 ; Lal, 2004 ).…”