Co-evolution of soil and water conservation policy and human–environment linkages in the Yellow River Basin since 1949

Policy plays a very important role in natural resource management as it lays out a government framework for guiding long-term decisions, and evolves in light of the interactions between human and environment. This paper focuses on soil and water conservation (SWC) policy in the Yellow River Basin (YRB), China. The problems, rural poverty, severe soil erosion, great sediment loads and high flood risks, are analyzed over the period of 1949–present using the Driving force–Pressure–State–Impact–Response (DPSIR) framework as a way to organize analysis of the evolution of SWC policy. Three stages are identified in which SWC policy interacts differently with institutional, financial and technology support. In Stage 1 (1949–1979), SWC policy focused on rural development in eroded areas and on reducing sediment loads. Local farmers were mainly responsible for SWC. The aim of Stage 2 (1980–1990) was the overall development of rural industry and SWC. A more integrated management perspective was implemented taking a small watershed as a geographic interactional unit. This approach greatly improved the efficiency of SWC activities. In Stage 3 (1991 till now), SWC has been treated as the main measure for natural resource conservation, environmental protection, disaster mitigation and agriculture development. Prevention of new degradation became a priority. The government began to be responsible for SWC, using administrative, legal and financial approaches and various technologies that made large-scale SWC engineering possible. Over the historical period considered, with the implementation of the various SWC policies, the rural economic and ecological system improved continuously while the sediment load and flood risk decreased dramatically. The findings assist in providing a historical perspective that could inform more rational, scientific and effective natural resource management going forwar

Roles of Dicer-Like Proteins 2 and 4 in Intra- and Intercellular Antiviral Silencing

RNA silencing is an innate antiviral mechanism conserved in organisms across kingdoms. Such cellular defense involves DICER or DICER-LIKEs (DCLs) that process viral RNAs into small interfering (vsi)RNAs. Plants encode four DCLs which play diverse roles in cell-autonomous virus-induced RNA silencing (known as VIGS) against viral invasion. However, intracellular VIGS can spread between cells, and the genetic basis and involvement of vsiRNAs in non-cell autonomous VIGS remains poorly understood. Here using GFP as a reporter gene together with a suite of DCL RNAi transgenic lines, we show that in addition to well-established activities of DCLs in intracellular VIGS and vsiRNA biogenesis, DCL4 inhibits intercellular VIGS whilst DCL2 is required, likely along with DCL2-processed/dependent vsiRNAs and their precursor RNAs, for efficient VIGS trafficking from epidermal to adjacent cells. DCL4 imposed an epistatic effect on DCL2 to impede cell-to-cell spread of VIGS. Our results demonstrate previously unknown functions for DCL2 and DCL4 which may form a dual defensive frontier for intra- and intercellular silencing to double-protect cells from virus infection in Nicotiana benthamiana

Estimation of water storage changes in small endorheic lakes in Northern Kazakhstan

Both climate change and anthropogenic activities contribute to the deterioration of terrestrial water resources and ecosystems worldwide, with Central Asia and its endorheic lakes being among the most severely affected. We used a digital elevation model, bathymetry maps and Landsat images to estimate the areal water cover extent and volumetric storage changes for eleven small terminal lakes in Burabay National Nature Park (BNNP) in Northern Kazakhstan from 1986 to 2016. Based on the analysis of hydrometeorological observations, lake water balance, lake evaporation and Budyko equations, driven by gridded climate and global atmospheric reanalysis datasets, we evaluate the impact of historical climatic conditions on the water balance of the BNNP lake catchments. The total surface water area of the BNNP lakes decreased by around 7% for that period, mainly due to a reduction in the extent of three main lakes. In contrast, for some smaller lakes, the surface area increased. Overall, we attribute the decline of the BNNP lakes’ areal extent and volume to the prolonged periods of water balance deficit when lake evaporation exceeded precipitation. However, during the most recent years (2013-2016) precipitation increased and the BNNP lake levels stabilized

Spatial analysis of hemorrhagic fever with renal syndrome in China

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) is endemic in many provinces with high incidence in mainland China, although integrated intervention measures including rodent control, environment management and vaccination have been implemented for over ten years. In this study, we conducted a geographic information system (GIS)-based spatial analysis on distribution of HFRS cases for the whole country with an objective to inform priority areas for public health planning and resource allocation. METHODS: Annualized average incidence at a county level was calculated using HFRS cases reported during 1994–1998 in mainland China. GIS-based spatial analyses were conducted to detect spatial autocorrelation and clusters of HFRS incidence at the county level throughout the country. RESULTS: Spatial distribution of HFRS cases in mainland China from 1994 to 1998 was mapped at county level in the aspects of crude incidence, excess hazard and spatial smoothed incidence. The spatial distribution of HFRS cases was nonrandom and clustered with a Moran's I = 0.5044 (p = 0.001). Spatial cluster analyses suggested that 26 and 39 areas were at increased risks of HFRS (p < 0.01) with maximum spatial cluster sizes of ≤ 20% and ≤ 10% of the total population, respectively. CONCLUSION: The application of GIS, together with spatial statistical techniques, provide a means to quantify explicit HFRS risks and to further identify environmental factors responsible for the increasing disease risks. We demonstrate a new perspective of integrating such spatial analysis tools into the epidemiologic study and risk assessment of HFRS