ABSTRACT

Unregulated land-use conversion influences soil organic carbon (SOC) storage and sequestration causing fluctuations. As one of the most vulnerable regions to climate-change impact, Caribbean ecosystems require formulation of strong adaptation strategies to cope with the vagaries of climate change. Therefore, understanding SOC dynamics under land-use change is critical. With increasing popularity of proximal soil sensing (PSS), relating obtained signals to properties of interest, could offer time and cost-efficient procedures for characterizing properties. To our knowledge, no investigation has been conducted employing PSS using electromagnetic-induction (EMI) to characterize the spatial dynamics of SOC as a consequence of transitional land-use. Hence, our research broadens the evidence base for the characterization of SOC in island ecosystems. Apparent electrical conductivity (ECa) measured by a DUALEM-1S sensor was used to characterize SOC at 0–0.3 m under different land-uses. Spatial maps showed that EMI was suitable for distinguishing between natural and anthropogenic land-uses, with anthropogenic land-uses generally having higher and more variable ECa values (Quarry = 22.8–30.5 mS m⁻¹, Agriculture = 5.0–11.3 mS m⁻¹, Residential = 39.2–60.0 mS m⁻¹, Forest = 9.3–14.5 mS m⁻¹, Grass = 13.6–17.0 mS m⁻¹). Natural land-uses had better soil quality indicating that SOC controls soil quality and varies in response to land-use.

摘要

不受管制的土地利用转换会影响土壤有机碳 (SOC) 的储存和封存，从而导致波动。作为最易受气候变化影响的地区之一，加勒比生态系统需要制定强有力的适应战略，以应对变化无常的气候变化。因此，了解土地利用变化下的 SOC 动态至关重要。随着近端土壤传感 (PSS) 的日益普及，将获得的信号与感兴趣的特性相关联，可以提供用于表征特性的时间和成本效益高的程序。据我们所知，尚未进行使用电磁感应 (EMI) 的 PSS 来表征过渡性土地利用导致的 SOC 空间动态的研究。因此，我们的研究拓宽了表征岛屿生态系统中 SOC 的证据基础。由 DUALEM-1S 传感器测量的表观电导率 (ECa) 用于表征不同土地利用下 0-0.3 m 的 SOC。空间图显示 EMI 适合区分自然和人为土地利用，人为土地利用通常具有更高和更可变的 ECa 值（Quarry = 22.8–30.5 mS m^-1，农业 = 5.0-11.3 mS m ^-1，住宅 = 39.2-60.0 mS m ^-1，森林 = 9.3-14.5 mS m ^-1，草 = 13.6-17.0 mS m ^-1）。自然土地利用具有更好的土壤质量，表明 SOC 控制土壤质量并随土地利用而变化。