Showing papers on "Schima wallichii published in 2020"

Airborne and belowground phytotoxicity of invasive Ageratina adenophora on native species in Nepal

Abstract: Volatile compounds from leaf litter of invasive alien Ageratina adenophora are known to inhibit growth of native species in sub-tropical Asia, but there is not much evidence if the litter affects tree species In particular, the relative importance of airborne inhibition versus belowground effect of invaded soil on tree species is rarely explored We used A adenophora uninvaded and invaded soils to follow germination and seedling growth of a native Nepalese tree Schima wallichii (DC) Korth in the presence and absence of leaf litter of A adenophora We also compared diversity of native species in the uninvaded and invaded sites in Nepal We found that A adenophora invasion is associated with lower native species richness and correlated with lower tree canopy cover Invaded soil and the proximity of A adenophora leaf litter decreased seed germination rate of S wallichii Both invaded soil and leaf litter of the weed inhibited S wallichii shoot and root biomass accumulation independently of each other As far as we know, this is the first study to report these two effects simultaneously In conclusion, belowground effects of A adenophora invaded soil and airborne effects of leaf litter have a potential to inhibit native tree regeneration in Nepalese Schima–Alnus forests Maintaining high canopy cover and removing litter of the weed should be tested to control its invasion

Assessing Environmental Control of Sap Flux of Three Tree Species Plantations in Degraded Hilly Lands in South China

Abstract: Prerequisite for selection of appropriate tree species in afforestation programs is to understand their water use strategy. Acacia mangium Willd., Schima wallichii Choisy, and Cunninghamia lanceolata (Lamb.) Hook are the three main vegetation restoration pioneer species in southern China, but no comparative research on the water use strategy of these three tree species have been reported. Our objective was to gain a detailed understanding of how photosynthetically active radiation (PAR), vapor pressure deficit (VPD), and soil water content (SWC) at different soil depths control the sap flux density (Js) in the dry and wet seasons. We measured the Js of these three tree species by using the thermal dissipation method in low subtropical China. We found that both S. wallichii and C. lanceolata differed clearly in their stomatal behavior from one season to another, while A. mangium did not. The canopy conductance per sapwood area of S. wallichii and C. lanceolata was very sensitive to VPD in the dry season, but not in the wet season. The Js of A. mangium was negatively correlated to SWC in all soil layers and during both seasons, while the other two species were not sensitive to SWC in the deeper layers and only positively correlated to SWC in dry season. Our results demonstrate that the three species have distinct water use strategies and may therefore respond differently to changing climate.

Patterns of nitrogen resorption efficiency among different functional groups of trees in a subtropical forest of Meghalaya

Abstract: Nutrient resorption (NR) from senescing leaves plays an important role in the conservation of nutrients in plants. The nutrient resorption efficiency depends on several factors including availability of soil nutrients, species type and leaf nutrient quality. Although several researchers have worked on the pattern of NR in deciduous and evergreen plants, it varied widely. Since the variations are species-specific and many functional groups prevailing in tropical and subtropical forests have not been studied, the understanding of NR pattern in varied functional groups remained incomplete. In this study, Nitrogen resorption efficiency (NRE) of four tree species belonging to different functional groups viz., Alnus nepalensis (non-leguminous nitrogen-fixing and deciduous), Lithocarpus dealbatus (broadleaved and evergreen), Pinus kesiya (coniferous and evergreen) and Schima wallichii (broadleaved semi-evergreen) were studied. NRE was greatest in Alnus nepalensis and Schima wallichii immediately before the maximum leaf fall and it decreased in the subsequent months. However, NRE in Lithocarpus dealbatus exhibited identical values across all the months in a year. In Pinus kesiya, the NRE was the lowest and it varied through six months. The nitrogen concentration in the leaves and NRE varied significantly among the species and across the months. The trees belonging to certain functional groups did not differ in their NREs in different months of a year due to the availability of alternate strategies to acquire nitrogen or being semi-/ evergreen in nature to cope up with their nutrient loss.

Impact of disturbance on vegetation, biomass and carbon stock in tropical forests of Tripura, Northeast India

Abstract: In this study, the impact of anthropogenic disturbances on vegetation, soil characteristics, biomass and carbon stock was studied in tropical mixed deciduous forests of Tripura, North-east India. The forests stands were selected based on the presumed disturbance index and categorized in three distinct categories viz. Least Disturbed Forests (LDF), Moderately Disturbed Forests (MDF) and Highly Disturbed Forests (HDF). The study revealed that species diversity is much higher in LDF followed by MDF and HDF sites. Few species like Anogeissus accuminata, Lannea coromandelica, Schima wallichii, and Syzygium cumini are common in all the three categories of forests. The Shannon–Wiener diversity index ranged from 1.32 to 2.51 in all the stands. The phytosociological parameters varied along the disturbance gradient in different stands. The maximum tree density was 198.57 trees ha−1 in LDF, 176.67 trees ha−1 in MDF and least in HDF (111.67 trees ha−1). Soil Organic Carbon (SOC %) recorded maximum in LDF (1.41–1.67%) and minimum in HDF (0.91–1.36%). Tree biomass showed a significant relation with soil organic carbon stock (r = 0.998, p < 0.05). Furthermore, the present study suggests the need for quantification of forest disturbance and biomass which will improve carbon budget estimates and lead to better parameterization of forest carbon cycle models.

Ability of Wayside Trees as Pb Absorbent on Jl Jenderal Soedirman Purwokerto

Abstract: Air pollution can be determined by using plants as a bioindicator. The purposes of this research were 1) to determine the ambient air Pb concentration and Pb concentration in some leaves of wayside trees on Jl Jenderal Soedirman Purwokerto, 2) to find out the stomata characteristics i.e. size and density of stomata related to their ability to absorb Pb. The research method used was the survey method. The wayside tree leaf samples were taken with purposive sampling. The variables used in the research include variables such as aerial Pb and Pb concentrations of leaves, while the dependent variable was anatomical responses. The main parameters observed in the form of air Pb concentrations, Pb in leaf and stomata anatomical characters. The support parameters are traffic density. The results of this study showed that the concentration of Pb in Jl Jenderal Sudirman within 1 hour is 0.0147 μg/m³. Pb concentration was the highest in the leaves of Schima wallichii (0.3524 ppm), and the lowest was in Hibiscus tiliaceus (0.2354 ppm). Pb accumulated in the leaves caused a very significant effect on the density, length, and width of the leaf stomata of shade plant on Purwokerto's Jenderal Sudirman Road. Pb concentration in leaves positively correlated with the density, length, and width of stomata (p<0.05).