Conversion of sub-tropical native vegetation to introduced conifer forest: Impacts on below-ground and above-ground carbon pools

Abstract

a b s t r a c tLand-use change can have a major influence on soil organic carbon (SOC) and above-ground C pools. We assessed a change from native vegetation to introduced Pinus species plantations on C pools using eight paired sites. At each site we determined the impacts on 0-50 cm below-ground (SOC, charcoal C, organic matter C, particulate organic C, humic organic C, resistant organic C) and above-ground (litter, coarse woody debris, standing trees and woody understorey plants) C pools. In an analysis across the different study sites there was no significant difference (P > 0.05) in SOC or above-ground tree C stocks between paired native vegetation and pine plantations, although significant differences did exist at specific sites. SOC (calculated based on an equivalent soil mass basis) was higher in the pine plantations at two sites, higher in the native vegetation at two sites and did not differ for the other four sites. The site to site variation in SOC across the landscape was far greater than the variation observed with a change from native vegetation to introduced Pinus plantation. Differences between sites were not explained by soil type, although tree basal area was positively correlated with 0-50 cm SOC. In fact, in the native vegetation there was a significant linear relationship between above-ground biomass and SOC that explained 88.8% of the variation in the data. Fine litter C (0-25 mm diameter) tended to be higher in the pine forest than in the adjacent native vegetation and was significantly higher in the pine forest at five of the eight paired sites. Total litter C (0-100 mm diameter) increased significantly with plantation age (R 2 = 0.64).Carbon stored in understorey woody plants (2.5-10 cm DBH) was higher in the native vegetation than in the adjacent pine forest. Total site C varied greatly across the study area from 58.8 Mg ha À1 at a native heathland site to 497.8 Mg ha À1 at a native eucalypt forest site. Our findings suggest that the effects of change from native vegetation to introduced Pinus sp. forest are highly site-specific and may be positive, negative, or have no influence on various C pools, depending on local site characteristics (e.g. plantation age and type of native vegetation). Crown

Functional Distribution of Bacterial Community under Different Land Use Patterns Based on FaProTax Function Prediction

“…Both of these processes would reduce the input of organic C into the soil environment and may also explain the reduction of soil total C and total N, suggesting the loss of soil carbon and nitrogen in the process of transforming forests into other land use patterns. Similarly, previous research hasreported that the concentration of soil organic carbon decreased after conversion of natural forests to Pinus plantations [5,10,54], which were similar to our study results.The input of carbon, nitrogen and organic matter in soil is mainly due to the return of nutrients and biological nitrogen fixation in the litter [55]. The biomass allocation strategies between coniferous forests and broad-leaved forests are different.…”

Effects of land use change from natural forest to plantation on C, N and natural abundance of 13C and 15N along a climate gradient in eastern China

“…Similarly, Lewis et al . 43 found that the effects of change from NF converted to introduced Pinus sp. plantations were highly site-specific and might have a positive, negative, or no influence on the variation of soil C values.…”

Carbon Stock Estimates due to Land Cover Changes at Sumber Brantas Sub-Watershed, East Java

“…Under cropland, the C input is low and the C output due to degradation is high. Increasing of erosion frequency within the first years also declined the soil C stock after forest conversion (Lewis et al, 2016). Amundson et al (2015) also reported that there were large declines of soil organic carbon on the conversion of natural habitats such as forest into agricultural land.…”