Carbon storage and soil property changes following afforestation in mountain ecosystems of the Western Rhodopes, Bulgaria

Abstract

Land-use changes and afforestation activities are widely recognized as possible measures for mitigating climate change through carbon sequestration. The present study was conducted to evaluate the effect of afforestation on (i) soil physical and chemical properties and soil carbon stocks in four mountain ecosystems and (ii) whole ecosystem carbon storage. The four experimental sites, situated in the Western Rhodope Mountains (Bulgaria) were characterized by typical forest-related land-use conversions. The four sites were a Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) plantation (Rd1) established on former cropland, a mixed black pine (Pinus nigra Arn.) with Scots pine (Pinus sylvestris L.) plantation (Rd2) established on former cropland, a cropland (RdA1) and an abandoned land with uncontrolled extensive grazing (RdA2) historically used as cropland. Soil parameters, i.e., sand content, pH, organic C and N contents, C/N ratio and soil organic carbon (SOC) stocks, were significantly affected by land use and land-use history. Conversion from cropland into forestland significantly reduced soil bulk density and coarse fragments at 0-10 cm depth. Compared with adjacent cropland and abandoned land, soils in coniferous plantations were acidified in their upper layers. Sites Rd2 and RdA2 contained the least SOC owing to the previous long-term arable cultivation (>100 years). Analysis of the ecosystem C stock distribution revealed that most of C in forests was stored in the aboveground tree biomass. Our study confirmed that afforestation of cropland turned the soil into a C sink for the selected mountain region, but showed conflicting results when afforestation occurred on abandoned cropland.

Carbon sequestration in the bio-edaphic ecosystem of National Highway-27 in Guwahati, Assam, India

“…(2018) (1.03–1.11%) in the roadside plantation of north-western Haryana, India. A variation was observed in the organic carbon content in the same layer of soil for different sample areas; this is similar to the findings of Zhiyanski et al. (2015) .…”

“…Soil organic carbon has an important function in the carbon cycle; hence, its presence and availability significantly influence climate change ( Smith, 2004 ; Vaccari et al., 2011 ). Our study found an organic carbon content of 2.76–7.6%, 2.1–6.51% and 1.64–6.34% at depths of 0–15 cm, 15–30 cm, and 30–45 cm respectively in all the studied sample areas which are higher than 0.35–4.14% in afforested land as reported by Zhiyanski et al. (2015) and Arya et al.…”

“…Thus, information on bulk density will assist in soil management and in future planning to enhance soil fertility by technological means ( Chaudhari et al., 2013 ). Several researchers reported an increase in bulk density according to soil depth in different land-use patterns ( Zhiyanski et al., 2015 ; Rahaman et al., 2018 ). Our study also found that the bulk density in the studied area increased with soil depth; however, bulk density at the 15–30 cm depth was statistically significant for all the studied sample areas at National Highway-27 in Guwahati, Assam.…”

Impact of land use change on organic carbon sequestration in Arenosol

“…SOC concentration in the Ap horizon in forest soil decreased during the study period by 0.9 mg kg -1 , while the losses in unfertilised soil in crop rotation were three times as high (2.7 mg kg -1 ). Similarly, Zhiyanski et al (2015) reported that in Bulgaria afforestation by coniferous species helped accumulate and preserve soil carbon, but even several decades after the conversion from arable cropland or abandoned land to forest land use, this effect was expressed only weakly and could not compensate the organic carbon loss due to previous active cultivation. Also in Northern Europe (Barcena et al 2014), afforestation with conifers for the periods <30 years and >30 years since afforestation revealed a shift from initial loss to later gain of SOC.…”

Alfalfa Powder Affects Soil Nutrient and Walnut Dry Matter Accumulation under Drought

“…Insufficient long‐term organic matter input to the soil can inhibit carbon (C) sequestration and nitrogen (N) fixation, reducing the capacity of soil C and N pools. Such constant and persistent low nutrient contents and water supplies reduce the biological production of aboveground plants and vegetation coverage, which would diminish C inputs to the soil and inactivate nutrient cycling in mountainous and hilly areas with poor soil (Potthast et al, 2012; Shimoda and Koyanagi, 2017; Willcock et al, 2014; Zhiyanski et al, 2016). Ecologists and agronomists have tried to increase soil C inputs and promote geochemical cycling in a variety of ways to prevent soil infertility, such as by adding high‐efficiency C sources (Yu et al, 2018), microbial fertilizers (Wu et al, 2018; Igiehon and Babalola, 2018), and soil improvement agents (Dannehl et al, 2016; Kathijotes et al, 2016); planting green manure (GM); and covering the soil with straw (He et al, 2018).…”