Divergent drivers of the spatial and temporal variations of cropland carbon transfer in Liaoning province, China

Abstract

Spatial and temporal variations are important points of focus in ecological research. Analysing their differences improves our understanding on the variations of ecological phenomena. Using data from the Liaoning Statistical Yearbook, we investigated the spatial and temporal variations of cropland carbon transfer (CCT), an important ecological phenomenon in quantifying the regional carbon budget, in particular, the influencing factors and difference. The results showed that, from 1992 to 2014, the average CCT in Liaoning province was 18.56 TgC yr−1 and decreased from northwest to southeast. CCT spatial variation was primarily affected by the ratio of planting area to regional area (RPR) via its effect on the magnitude of carbon transfer (MCT), which depended mainly on fertilizer usage per area (FUA). From 1992 to 2014, CCT exhibited a significantly increasing trend with a rate of 0.48 TgC yr−1. The inter-annual variation of CCT was dominated by carbon transfer per planting area (CTP) through its effect on MCT, which significantly correlated with FUA but showed no significant correlation with climatic factors. Therefore, the factors affecting the spatial variation of CCT differed from those that affected its inter-annual variation, indicating that the spatial and temporal variations of ecological phenomena were affected by divergent factors.

Multiscale environmental heterogeneity in a large river-floodplain system

“…Lateral river-floodplain gradients across the MU and AU were evaluated using the nonparametric Mann-Kendall method (MK) (Kendall, 1975;Mann, 1945). The temporal gradient was substituted with the spatial gradient, which is an usual practice in environmental sciences (Zhu et al, 2017). Mean values of measured variables in each aquatic environment were ordered in a spatial sequence along the gradients of hydrological connectivity to a MR.…”

The Spatial Disequilibrium and Dynamic Evolution of the Net Agriculture Carbon Effect in China

“…(1) The existing literature on the net carbon effect of agriculture is mainly from the perspective of geographical location, and there is a lack of studies that take the net carbon effect of agriculture in food production functional areas as the object of investigation. (2) The existing literature on carbon sink measurement is mostly focused on the crop level, while there are fewer studies that include forest land and grassland in the carbon sink measurement system. (3) The existing literature only gives a brief description of the current situation of agricultural net carbon effect through descriptive statistical analysis and does not deeply discuss the evolution trend in agricultural net carbon effect from a spatial perspective.…”

“…Each functional food production area has different resource endowments, functional plans and economic structures. Distinctive geographical types of agriculture have been formed, generating different amounts of carbon sinks, sources and net carbon sinks [2]. This poses a serious challenge to the coordinated development of low-carbon agriculture.…”