Energy crop production in an urban area: a comparison of habitat types and land use forms targeting economic benefits and impact on species diversity

Responses of resident (DNA) and active (RNA) microbial communities in fluvial biofilms under different polluted scenarios

Pollution from human activities is a major threat to the ecological integrity of fluvial ecosystems. Microbial communities are the most abundant organisms in biofilms, and are key indicators of various pollutants. We investigated the effects some human stressors (nutrients and heavy metals) have on the structure and activity of microbial communities in seven sampling sites located in the Ter River basin (NE Spain). Water and biofilm samples were collected in order to characterize physicochemical and biofilm parameters. The 16S rRNA gene was analysed out from DNA and RNA extracts to obtain α and β diversity. Principal coordinates analyses (PCoA) of the operational taxonomic units (OTUs) in the resident microbial community revealed that nutrients and conductivity were the main driving forces behind the diversity and composition. The effects of mining have had mainly seen on the taxonomic composition of the active microbial community, but also at the OTUs level. Remarkably, metal-impacted communities were very active, which would indicate a close link with the stress faced, that is probably related to the stimulation of detoxification.

The Construction of a Regional Ecological Security Pattern Based on Circuit Theory

The construction of an ecological security pattern (ESP) is one of the basic methods to protect regional ecological security and enhance people’s well-being. In the case of Anhui province, located in the Yangtze River Delta region of China, regional ecological sources were assessed and recognized in terms of ecosystem services, and regional ESP was then constructed based on circuit theory. Current density was applied to analyze the significance of patches and corridors and recognize sticking points, and thereby strategies were introduced to optimize regional ESP. Results of ecosystem services function assessment showed that there were 47 ecological patches, 107 ecological corridors, 16 pinch points, and six sticking points in the ESP of Anhui province. The watershed of the Yangtze and Huai rivers divides the ESP of the northern and southern Anhui, which has huge landscape spatial heterogeneity. Areas with relatively good ecological resources were basically located between Dabie Mountain area in the west and the low hilly area in the south of Anhui, with mostly woodland and farmland as ecological sources. However, cities in the northern Anhui, also in the north of the watershed of the Yangtze and Huai rivers, face severe situations in terms of environmental protection. This study conducted spatial analyses on ESP with different thresholds and proposed to classify different ESPs according to ecological control. This helps to alleviate the contradiction between economic development and environmental protection, and improve the supply capacity of regional ecosystem services, in order to satisfy the regional demand for ecosystem services. Meanwhile, this study offers more methods to construct regional ESP and introduces targeted measures to improve connectivity, which is of practical guidance for the connectivity and optimization of ecological patterns.