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This study discovers the distribution of vegetation in the Sougna Mountain and its modern pollen representation and investigates the relationships with environment and land use variables. A total of 31 moss polsters were collected between 138 and 1364 m above sea-level from wooded to open areas (e.g. cork oak forest, pine reforestation, and shrubland). At each sampling site land use and environment variables were collected. The vegetation in the Sougna Mountain is scattered in a mosaic along three vegetation belts which are displayed in distinct pollen assemblages dominated by the pollen equivalents of the vegetation types (Quercus suber forest, matorrals of Erica spp. and Cistus spp. and Pinus pinaster reforestation). The variation between the variables and pollen data was performed using CCA analysis. The anthropogenic variables such as grazing, and cultivation, contribute to discrimination of the degraded and grazed areas. High precipitation and altitude have a rather good correlation to wooded communities and consequently a good relation to the tree cover. Our results show that the pollen types of Poaceae, Cannabis, Plantago, Nicotiana, Asteraceae, and Urtica are related mostly to human practice and distinguish the disrupted communities. The presence of those taxa in the pollen diagram must be interpreted carefully. A high taxonomic resolution is recommended to prevent the overestimation of the abundance of some taxa. Our results contribute to the advancement of palynological reconstructions of past vegetation and land use in Sougna Mountain and generally in the Rif landscape. [ABSTRACT FROM AUTHOR]

Background: Soil microorganisms are in constant interaction with plants, and these interactions shape the composition of soil bacterial communities by modifying their environment. However, little is known about the relationship between microorganisms and native plants present in extreme environments that are not affected by human intervention. Using high-throughput sequencing in combination with random forest and co-occurrence network analyses, we compared soil bacterial communities inhabiting the rhizosphere surrounding soil (RSS) and the corresponding bulk soil (BS) of 21 native plant species organized into three vegetation belts along the altitudinal gradient (2400–4500 m a.s.l.) of the Talabre–Lejía transect (TLT) in the slopes of the Andes in the Atacama Desert. We assessed how each plant community influenced the taxa, potential functions, and ecological interactions of the soil bacterial communities in this extreme natural ecosystem. We tested the ability of the stress gradient hypothesis, which predicts that positive species interactions become increasingly important as stressful conditions increase, to explain the interactions among members of TLT soil microbial communities. Results: Our comparison of RSS and BS compartments along the TLT provided evidence of plant-specific microbial community composition in the RSS and showed that bacterial communities modify their ecological interactions, in particular, their positive:negative connection ratios in the presence of plant roots at each vegetation belt. We also identified the taxa driving the transition of the BS to the RSS, which appear to be indicators of key host-microbial relationships in the rhizosphere of plants in response to different abiotic conditions. Finally, the potential functions of the bacterial communities also diverge between the BS and the RSS compartments, particularly in the extreme and harshest belts of the TLT. Conclusions: In this study, we identified taxa of bacterial communities that establish species-specific relationships with native plants and showed that over a gradient of changing abiotic conditions, these relationships may also be plant community specific. These findings also reveal that the interactions among members of the soil microbial communities do not support the stress gradient hypothesis. However, through the RSS compartment, each plant community appears to moderate the abiotic stress gradient and increase the efficiency of the soil microbial community, suggesting that positive interactions may be context dependent. [ABSTRACT FROM AUTHOR]

Involving of new territories not used before into different industry forms including construction of boreholes for gas exploring requires detailed revealing and comprehensive analysis of physical-geographic and environmental conditions of concrete territories. It concerns especially easily destroyable components of biota (a biome) such as vegetation cover. Underestimation of the specifics of structural-dynamic organization of phytocoenoses in concrete ecotopes can result in the destruction of vegetation up to its complete decay. Using one of gas-bearing area in Irkutsk Region, we tried to make possible characteristics of vegetation spatial stratigraphy and its responses to some impacts while constructing boring holes under existing environmental conditions. [ABSTRACT FROM AUTHOR]

The eruption of Anak Krakatoa Volcano is assumed to be the cause to generate tsunami wave; it can also be assumed that the wave source is only about 50.3 km from the coast. The interesting point is that the propagation of the tsunami wave was not caused by an earthquake but rather by volcanic material from Anak Krakatoa Volcano which slid into the sea. An investigation was conducted using spatial analysis of coastal areas around Tanjung Lesung, Banten with GIS analysis. While the propagation of tsunami waves was calculated from Anak Krakatoa Volcano that was projected towards Tanjung Lesung, Banten. These analyses were done to obtain assumptions of the wave velocity and propagation time from the center of the wave to the coastal area. The primary purpose of this study is to investigate the effectiveness of the vegetation belts as tsunami mitigation. This study used a 2D numerical simulation wave based on a VOF method. The numerical simulation calculated the interaction between the bore wave propagation and the vegetation belts. Numerical analysis was done to estimate the altitude and velocity of tsunami waves toward the coastal area of Tanjung Lesung. By comparing the results of the spatial and numerical analysis, the delineation of the tsunami-affected area on 31 December 2018 can be determined. [ABSTRACT FROM AUTHOR]

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Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Forest vegetation in view of some scenarios of climate change in Italy. The study analyses the relationship between the distribution of the main Italian forest vegetation types and the conditions during average temperature of the coldest month, at present and those predicted for scenarios A2a and B2a of the GCM HADCM3 until the year 2080. With an increased average temperature of the coldest month up to 4.4 °C in 2080, current temperature values for the main forest species will change greatly, creating favorable preconditions for an increased presence of broadleaved deciduous species in mountain altitudes of the Alps, more termophilous broadleaved species on those of the Appennines and more Mediterranean species on lower mountains, hills and lowlands of the country. The results are compared with previsional models of tree species distribution due to predicted climate changes, and the possible influence of some ecological factors is discussed. [ABSTRACT FROM AUTHOR]

Modern proxy-calibration studies are a powerful tool for paleoecological interpretation. This paper analyzes the relationships among modern pollen rain, vegetation and altitude in the central Pyrenees, where several paleo-palynological studies have been developed, but a modern analog survey is still unavailable. The work analyzes the pollen content of moss polsters from different vegetation communities along an altitudinal transect, as well as the flora and vegetation using the Braun-Blanquet system. DCCA showed that altitude satisfactorily explains both vegetation (r2 = 0.988) and pollen (r2 = 0.841) gradients. Besides the complexity of pollen-vegetation relationships, some regularities were found to be useful for paleoecological and paleoenvironmental interpretation. In general, altitudinal vegetation and pollen patterns show similarities, but pollen belts and boundaries are less well defined, likely because of the homogenizing effect of upward wind transport. Palynological differentiation of montane from subalpine/alpine belts is straightforward from the trends of the more significant pollen types, mainly the low-altitude deciduous trees and the high-mountain herbs. Palynological differences between subalpine and alpine belts, which boundary coincides with the treeline, are more subtle and need quantitative criteria and complementary proxies. From an individual point of view, four main groups of pollen were distinguished, in relation to their usefulness as vegetation and altitudinal indicators: (1) very good indicators, (2) good indicators, (3) non indicators, and (4) allochthonous pollen types. The first two groups resulted to be useful as indicator taxa for modern analogs for paleovegetational and paleoaltitudinal reconstruction, while the latter two groups should be interpreted with caution in paleoenvironmental studies. [ABSTRACT FROM AUTHOR]