Modern Analog Assemblages of Phytoliths Under Various Plant Communities of the Middle Volga and their Applicability for Archaeological Reconstructions

The article describes the results of investigations of the sub-recent assemblages of silica phytoliths in top soils of various modern plant communities of the Middle Volga region in Tatarstan, Samarskaya and Ulyanovskaya oblasts conducted in 2017–2020. Counts of various phytolith morphotypes from 40 samples suggest a relatively low level of vegetation community specificity as revealed by multivariate statistical analyses. Nevertheless, coniferous and mixed forests can be distinguished based on the presence of a suite of conifer phytoliths, while steppes can be identified based on high proportion of rondels. Deciduous forests of the region can be detected based on high proportion of straight elongates and acutous bulbosus (trichome) type. Some matchings are made to 10 archaeological samples from various strata and ages across the region. Such samples reveal high proportion of cultured grass phytoliths and are most similar to steppes or agricultural assemblages in the modern dataset.

Spatial associations between plants and vegetation community characteristics provide insights into the processes influencing plant rarity

Determining the drivers of plant rarity is a major challenge in ecology. Analysing spatial associations between different plant species can provide an exploratory avenue for understanding the ecological drivers of plant rarity. Here, we examined the different types of spatial associations between rare and common plants to determine if they influence the occurrence patterns of rare species. We completed vegetation surveys at 86 sites in woodland, forest, and heath communities in south-east Australia. We also examined two different rarity measures to quantify how categorisation criteria affected our results. Rare species were more likely to have positive associations with both rare and common species across all three vegetation communities. However, common species had positive or negative associations with rare and other common species, depending on the vegetation community in which they occurred. Rare species were positively associated with species diversity in forest communities. In woodland communities, rare species were associated negatively with species diversity but positively associated with species evenness. Rare species with high habitat specificity were more clustered spatially than expected by chance. Efforts to understand the drivers of plant rarity should use rarity definitions that consider habitat specificity. Our findings suggest that examining spatial associations between plants can help understand the drivers of plant rarity.

Vegetation Community Characteristics Under Different Vegetation Eco-restoration Techniques at Xiangjiaba Hydropower Station

The objective of this study is to understand the characteristics of vegetation communities under different vegetation eco-restoration models (vegetation concrete eco-restoration technique, frame beam filling soil technique, thick layer base material spraying technique, and external soil spray seeding technique). Vegetation coverage, dominant species, species composition, and species diversity of vegetation community under different vegetation eco-restoration modes were analyzed by field survey. The vegetation community of the abandoned slag slope was unstable due to the simple vegetation community structure. The species and number of the thick layer base material spraying slope were low and fail to form a healthy multilayer community structure due to invade of Leucaena leucocephala (Lam.) de Wit. Studying the allelopathy of Leucaena leucocephala (Lam.) de Wit and seeking the best species composition that can coexist with it is significant to promote the positive succession of the vegetation community. The frame beam filling soil technique, external-soil spray seeding technique, and vegetation concrete eco-restoration technique can effectively promote the succession process of the vegetation community and have well water and soil conservation capacity. These findings suggest that artificial vegetation eco-restoration measures can effectively promote vegetation eco-restoration and the positive succession of vegetation community of disturbed slopes. The research results can provide scientific advice for vegetation eco-restoration and subsequent control and management of disturbed slopes in the Xiangjiaba project, and also can be helpful to other similar projects.

Vegetation community and species association of Castanopsis spp. at its habitat in the remnant forest of Cibodas Botanical Garden, Indonesia

Nurdiana DR, Buot IE Jr. 2021. Vegetation community and species association of Castanopsis spp. at its habitat in the remnant forest of Cibodas Botanical Garden, Indonesia. Biodiversitas 22: 4799-4807. Castanopsis is one of the genera of Fagaceae with a large distribution in Indonesia. The genus can be found easily in Java, Sumatera and Kalimantan. Several studies have found an association between Castanopsis and environmental factors dealing with the diversity, dispersal and propagation. So far, there has been no agreement on how Castanopsis interacts with other species within the same genus in nature, especially in the remnant forest under a fragmented state. The objectives of the study were to determine the vegetation associated with Castanopsis and whether each species of the genus Castanopsis co-occur within the remnant forest? A total of 60 plots have been studied in 3 different sites of the remnant forest. The nested sampling method was used to identify the trees, saplings and seedlings. Sixty-seven total species of trees, 140 species of saplings and 121 species of seedlings in Cibodas Botanical Garden remnant forest were recorded. The diversity index for tree, sapling and seedling were 3.5, 3.9 and 4.1, respectively, while evenness index for tree, sapling and seedling were 0.81, 0.8 and 0.85 respectively. The interspecific association of the genus Castanopsis was restricted to C. javanica x C. tungurrut. They are associated positively at sapling stage with Jaccard index of 0.2. However, at tree stage, there was no association out of the pair, C. javanica x C. tungurrut. Competition within genus Castanopsis occurred in the same habitat, though at a lesser degree which needs to be studied further. Dominance of many pioneer species (Oreocnide integrifolia (Gaudich.) Miq., Ostodes paniculata Blume, Cestrum aurantiacum Lindl. and others) at tree stage had been evident. This implies that the Cibodas remnant forest is still in the process of succession towards a more stable climax state.

Vegetation community changes in response to phragmites management at Times Beach, Buffalo, New York

Management of invasive phragmites (Phragmites australis [Cav.] Trin. Ex Steud.) in the United States has proven challenging over the last several decades. Various methods for control exist, but integrated approaches appear to have the most success. However, documentation of vegetation community–wide responses to these approaches remains limited. This study monitored plant community changes at Times Beach, New York, over a five-year period. In concert with mowing and thatch removal in all areas, the study evaluated two herbicides separately and together, representing three experimental treatment areas (TAs), for control efficacy by measuring plant community structure. Phragmites was targeted for treatments, avoiding native and nonproblematic non-native species when possible, to preserve beneficial habitat during phragmites control efforts. Monitoring results showed significant drops in phragmites relative cover, relative frequency, and importance values due to integrated management, regardless of herbicide treatment, with corresponding increases in these same values for native and other plant species. This suggests that prudent removal of phragmites is compatible with beneficial plant restorative efforts to maintain and improve habitat in infested areas.

Vegetation degradation assessment in the agricultural zone of Northern Mongolia

We conducted research to assess vegetation degradation in Selenge province described as the agricultural zone.Our research results based on the vegetation community map showed that 46.7 % of the total area is light, 3.3 % is moderate,13.9 % is strong, and 30.4 % is very strong degraded. Vegetation degradation was mostly observed in river valleys, lowerplains, hills and small mountains and mountain slopes due to the intensity of summer grazing. The moderately degraded areawas often winter places using as rotate or properly managed grazing land and light degradation has occurred in the forest area.Very strong degradation was revealed mainly in Saikhan, Orkhon, Javkhlant sub-provinces and strongly degraded in Sant,Orkhontuul, Baruunburen. Light degradation of vegetation were observed in sub-provinces adequately covered by forestincluding Eruu, Tushig, Shaamar, Khuder, but there are still problems related to mining and deforestation.