Floristic Composition, Diversity and Plant Community Along Elevational Gradients in the Afro-alpine Vegetation of Abohoy Gara Mountain, northern Ethiopia

This research was conducted in Afro-alpine vegetation of Abohoy Gara Mountain in northern Ethiopia with the aim of analyzing floristic composition along elevational gradients, threats and conservation methods. Data were collected from 53 quadrats (15 m x 15 m) laid at 100 m interval along parallel vertical transects spaced at 500m to each other to record shrubs and trees, whereas 1 m x 1 m plots were used to record herbs. Cover abundance data were used to do community analysis using R version 3.1.2 software. Analysis of variance (ANOVA) was employed to determine significant level of species richness; abundance and Shannon diversity index along elevational gradient, whereas pearson’s correlation test was applied to check the relationship between environmental variables with species richness, species abundance and Shannon diversity index (H’) using SPSS v20. Ninety-seven plant species composed of 82 genera under 40 families were recorded. The mean number of plant species showed significant difference along elevational gradient (P < 0.05). Besides, significant (P < 0.05) negative correlation of elevation with the plant richness, abundance as well as Shannon diversity index had been observed. Based on dominant species, a total of five plant communities were identified. The maximum plant diversity occurred in community type III (3.79), whereas the least plant diversity occurred in community type IV and community type V. Vegetation cover and species composition of Abohoy Gara Mountain is being endangered by agricultural expansion, over grazing and logging of wood for construction material. Hence, it needs application of complementary on-site and offsite conservation approaches. This calls for further joint management of the Abohoy Gara Mountain by the local people and administrative bodies in the overall conservation actions that can save and rehabilitate the plant resources and their habitats.

Biomass and Species Diversity of Different Alpine Plant Communities Respond Differently to Nitrogen Deposition and Experimental Warming

The ability of fragile ecosystems of alpine regions to adapt and thrive under warming and nitrogen deposition is a pressing conservation concern. The lack of information on how these ecosystems respond to the combined impacts of elevated levels of nitrogen and a warming climate limits the sustainable management approaches of alpine grasslands. In this study, we experimented using a completely random blocked design to examine the effects of warming and nitrogen deposition on the aboveground biomass and diversity of alpine grassland plant communities. The experiment was carried out from 2015 to 2018 in four vegetation types, e.g., alpine desert, alpine desert steppe, alpine marsh, and alpine salinised meadow, in the Aerjin Mountain Nature Reserve (AMNR) on the Qinghai–Tibetan Plateau (QTP). We found that W (warming) and WN (warming plus N deposition) treatment significantly increased the aboveground biomass of all the vegetation types (p < 0.05) in 2018. However, W and WN treatment only significantly increased the Shannon diversity of salinised meadows in 2018 and had no significant effect on the Shannon diversity of other vegetation types. Such results suggested that long-term nitrogen deposition and warming can consistently stimulate biomass accumulation of the alpine plant communities. Compared with other vegetation types, the diversity of alpine salinised meadows are generally more susceptible to long-term warming and warming combined with N deposition. Warming accounts many of such variabilities, while short-term N deposition alone may not significantly have an evident effect on the productivity and diversity of alpine grasslands. Our findings suggested that the effects of short-term (≤4 years) N deposition on alpine vegetation productivity and diversity were minimal, while long-term warming (>4 years) will be much more favourable for alpine vegetation.

Assessing Climate Change Trends and Their Relationships with Alpine Vegetation and Surface Water Dynamics in the Everest Region, Nepal

The Himalayas, especially the Everest region, are highly sensitive to climate change. Although there are research works on this region related to cryospheric work, the ecological understandings of the alpine zone and climate impacts are limited. This study aimed to assess the changes in surface water including glacier lake and streamflow and the spatial and temporal changes in alpine vegetation and examine their relationships with climatic factors (temperature and precipitation) during 1995–2019 in the Everest region and the Dudh Koshi river basin. In this study, Landsat time-series data, European Commission’s Joint Research Center (JRC) surface water data, ECMWF Reanalysis 5th Generation (ERA5) reanalysis temperature data, and meteorological station data were used. It was found that the glacial lake area and volume are expanding at the rates of 0.0676 and 0.0198 km3/year, respectively; the average annual streamflow is decreasing at the rate of 2.73 m3/s/year. Similarly, the alpine vegetation greening as indicated by normalized difference vegetation index (NDVI) is increasing at the rate of 0.00352 units/year. On the other hand, the annual mean temperature shows an increasing trend of 0.0329 °C/year, and the annual precipitation also shows a significant negative monotonic trend. It was also found that annual NDVI is significantly correlated with annual temperature. Likewise, the glacial lake area expansion is strongly correlated with annual minimum temperature and annual precipitation. Overall, we found a significant alteration in the alpine ecosystem of the Everest region that could impact on the water–energy–food nexus of the Dudh Koshi river basin.

Root Characteristics and Water Erosion-Reducing Ability of Alpine Silver Grass and Yushan Cane for Alpine Grassland Soil Conservation

In Taiwan, intensive forest fires frequently cause serious forest degradation, soil erosion and impacts on alpine vegetation. Post-fire succession often induces the substitution of forest by alpine grassland. Alpine silver grass (Miscanthus transmorrisonensis Hay.) and Yushan cane (Yushania niitakayamensis (Hay.) Keng f.) are two main endemic species emerging on post-fire alpine grassland. These species play a major role in the recovery of alpine vegetation and soil conservation of alpine grassland. However, their root traits, root mechanical properties and water erosion-reducing ability have still not been well studied. In the present study, root characteristics were examined using a complete excavation method. Root mechanical characteristics were estimated by utilizing the uprooting test and root tensile test, and hydraulic flume experiments were performed to investigate the water erosion-reducing ability using 8-month-old plants. The results show that the root architecture system of Alpine silver grass belongs to fibrous root system, while the Yushan cane has sympodial-tufted rhizomes with a fibrous root system. Root characteristics reveal that relative to Alpine silver grass, Yushan cane has remarkably larger root collar diameter, higher root biomass, larger root volume, higher root density, and a higher root tissue density. Furthermore, uprooting resistance of Yushan cane is notably higher than that of Alpine silver grass. However, the root tensile strength of Alpine silver grass is significantly higher than that of Yushan cane. Additionally, hydraulic flume experiments reveal that Yushan cane has significantly lower soil detachment rates than that of Alpine silver grass. Collectively, these findings clearly show that Yushan cane has superior root characteristics and water erosion-reducing ability than Alpine silver grass and is thus more suitable for the conservation of alpine grassland.

The Eurasian Dry Grassland Group (EDGG) in 2019–2020

This report summarizes the activities and achievements of the Eurasian Dry Grassland Group (EDGG) from July 2019 to December 2020. During this period, Covid-19 allowed only one live event, the 14th EDGG Field Workshop to the alpine vegetation of Switzerland, organised ad hoc as a replacement for the cancelled Field Workshop in the Ukrainian steppes. The cancelled Eurasian Grassland Conference in Spain found a partial replacement in “Talk Grasslands!”, a series of online talks during winter 2020/2021. EDGG’s own diamond open access periodical, Palaearctic Grasslands, is a novel combination of scientific journal, photo magazine and member newsletter. With five issues during the reporting time it contributed much to EDGG’s attractiveness. EDGG edited four Special Features in international journals (Tuexenia, Hacquetia, Flora) and contributed 13 chapters on grasslands and shrublands of the Palaearctic biogeographic realm to the Encyclopedia of the world’s biomes. EDGG’s vegetation-plot database GrassPlot with multi-scale and multi-taxon diversity data of grasslands and other open habitats of the Palaearctic is now integrated into the EDGG website with the GrassPlot Diversity Explorer.