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Afforestation is the primary ecosystem measure to address the issue of ecosystem degradation in in the Horqin sandy region of northern China. However , It is yet unclear how afforestation may affect the recovery of sandy grassland. This study took the ecological stoichiometry as indicators, and conducted a field investigation and indoor analysis to assess the afforestation strategies of three indigenous tree species for the restoration of sandy grassland , three restoration strategies were: (1) grasslands were enclosed via a Populus × beijingensis shelterbelt (FG); (2) Pinussylvestris var. mongolica was used for the afforestation of small, well-distributed grassland patches (MG); (3) Ulmus pumila was used for the afforestation of small, well-distributed patches (UG). Our result showed that the C, N, and P contents as well as the C: N: P ratio in plants, litters, and soils varied significantly between FG, MG, and UG. All three treatments were found to significantly impact the soil ratios of C:N, N:P, and C:P relative to CK treatment after more than 20 years of recovery. The results of N : P in different tissues showed that FG , MG and UG vegetation restorations were N-limited. N and P homeostasis was present in trees, especially Ulmus pumila, while the degree of homeostasis was significantly impacted by afforestation species and plant tissues. The N:P results suggested that lower N deficiency stress may have been experienced by three experimental plants. We concluded that UG was better suited to the dry climate in Horqin Sandy Land.

Disseminated visceral coccidiosis (DVC) is a widely distributed intestinal and extraintestinal disease of cranes caused by eimeriid coccidia and has lethal pathogenicity to several crane species. Here, feces of 164 black-necked cranes collected in Dashanbao Black-necked Crane National Nature Reserve, China, were examined to determine the prevalence of coccidial oocysts. Of the 164 fecal samples, 76 (46.3%) were positive for oocysts of Eimeria, including E. gruis in 59 (35.9%), E. reichenowi in 52 (31.7%), and E. bosquei in 47 (28.7%) by microscopic observation. Sixty-eight (89.5%) of these positive samples included two or more morphologically identifiable species of Eimeria. The nearly full length 18S rRNA gene (18S rRNA; about 1.8 kb) and partial mitochondrial cytochrome c oxidase I gene (COX1; about 1.3 kb) from oocysts of each morphologically distinct species of Eimeria were amplified, sequenced, and analyzed. BLAST searches using these new 18S rRNA sequences for E. gruis, E. reichenowi, or E. bosquei showed the most similar sequences were those of E. gruis (98.7–99.7% identity), E. reichenowi (97.9–100% identity), or E. gruis (98.6–99.6% identity) isolated from different species of Grus. BLAST searches using the new COX1 sequences for the three species of Eimeria showed that no nucleotide sequences of Eimeria and Isospora coccidia in GenBank have more than 83.0% identity with these species. Identities among the new COX1 sequences were 91.8% for E. gruis and E. reichenowi, 94.5% for E. gruis and E. bosquei, and 91.3% for E. reichenowi and E. bosquei. Phylogenetic analysis based on 18S rRNA or COX1 sequences indicated that Eimeria spp. in black-necked cranes were clustered together with other previously identified Eimeria species from different cranes.

Planning for extensive cascading hydropower dam exploitation in the southwest of China has been the subject of debate and conflict in recent years. The middle reach of the Lancang-Mekong River, a typical region for cascading hydropower dam construction, was selected as a study area to explore the composition, biomass and biological integrity of phytoplankton assemblages before and after such construction. Sampling sites along the longitudinal gradient of this river were chosen to measure phytoplankton assemblages in 1988 (pristine state), 1997 (completion of the first dam), and 2011 (cascading dams). The results indicated that composition and abundance were greatly altered by the construction and operation of cascading dams. The phytoplankton assemblages were found to be sensitive indicators in the assessment of aquatic ecosystem health degradation associated with cascading dams. The phytoplankton index of biotic integrity (P-IBI) was developed as a comprehensive and quantitative index to assess the variation in biological integrity and aquatic ecosystem degradation before and after the construction of cascading dams. The effects of the cascading dams on the aquatic ecosystem were serious and more complex than the effects of a single dam. The ecological and longitudinal connectivity of the aquatic ecosystem and the natural diversity of aquatic habitats transitioned in several impoundment areas due to the influence of the cascading dams. Increasing abundance and biomass of phytoplankton assemblages in reservoir areas can lead to degradation of the aquatic ecosystem compared with natural riverine ecosystems. Cascading hydropower dams can cause cascades and accumulation effects on the riverine ecosystem.

The Lancang-Mekong River basin contains a diverse assemblage of freshwater fish species; however, their populations are threatened by current and planned dam construction along the river. Fish assemblages are sensitive indicators of environmental degradation and can be used to assess aquatic ecosystem health. This research compared the fish fauna at the Xiaowan hydropower dam located on the middle reaches of the Lancang-Mekong River at three time periods: in 2008 (before impoundment), 2010 (water storage) and 2011 (full operation). A modified fish index of biological integrity (modified F-IBI) was developed and it synthesized information on the taxonomic composition, trophic guilds, and tolerance levels of the fish and habitat diversity to quantitatively assess the condition of fish populations before and after damming. This index also was used to assess the longitudinal diversity of the fish fauna along the river channel and could assess the barrier effect associated with the dam. Jaccard's index of similarity was used as a feasible tool to assess fish diversity loss and biotic homogenization. The analysis clearly showed a homogenization of the fish communities after damming, and the reservoir impoundment region showed much more serious homogenization than the downstream region. The Xiaowan dam had an immediate and profound effect on the fish fauna in this region of the Lancang-Mekong River. A total of eight cascading dams are planned for development in this region, and, unless conservation mitigation efforts are considered, the results could be devastating on the native fish populations of middle reaches of the Lancang-Mekong River basin.

The extensive number of hydropower dams being planned in southwest China has attracted much attention in recent years. Eight cascading dams along the middle and lower reaches of the Lancang-Mekong River basin were selected to assess the riparian and upland vegetation. A total of 24 transects and 126 quadrats perpendicular to the river channel were surveyed from upstream to downstream. By using two-way indicator species analysis (TWINSPAN), the vegetation types in this region were classified into 21 vegetation classes. The ecological gradient analysis was completed using canonical correspondence analysis (CCA) and demonstrated that the dominant environmental factors impacting vegetation distribution were the variations in latitude and altitude. The vegetation impact index (VII) was developed as a quantitative index to assess the impact of dam inundation and operation on the upland and riparian vegetation. The values of VII showed that the most endangered vegetation communities were the shrub and herb communities in riparian habitats along this river. The effects of cascading hydropower dams on riparian and upland vegetation distribution were more complex than those of single dams. Cascading hydropower dams can enhance habitat fragmentation, reduce the distribution ranges (latitude and altitude) of primary vegetation and reduce the complexity of the vegetation types along the river as well as induce the loss of primary vegetation in the whole watershed.

Lancang-Mekong River Basin is one of ecoregions with rich biodiversity and high ecological values in the world. The basin has been strongly affected by human activities, particularly by dam construction. This study was conducted to investigate the vegetation distribution patterns in the dam areas along middle-low reach of the Lancang-Mekong River in Yunnan Province of China, where eight cascade dams have been planned or are being constructed. To identify the vegetation composition and structure, we sampled 126 quadrats along the transects arrayed vertically to both side of river channel from the year of 2004 to 2010. We found that the forest, shrub and grass communities were widely spread along the riverside. In low reach watershed of the Lancang-Mekong River, the dominated vegetations were grasses and shrubs which were severely disturbed by human activity. In middle reach of the Lancang-Mekong River, the dry-hot valley vegetation was found in the low valley. At high altitude, the pine forest and semi-evergreen seasonal forest were found. As a result of dam construction and operation, the structure and compositions of riparian vegetation were strongly changed. Some plants declined or disappeared due to the alteration of their habitats. The protection or restoration interventions are urgently needed to mitigate the risk of vegetation damage associated with dam projects along middle and low reach of the Lancang-Mekong River.