The microbial landscape: soil microbiome properties predict plant species distributions

Background: All human land use (LU) affects the distribution of plant species; however, the impacts vary with the type/intensity of LU. For managing ecosystems, it is therefore essential to understand the effects of LU types on the distribution of plant species on a macroscale.Aims: The objectives of our study were to quantify the effects of various LU types on the distribution of vascular plant species in Japan and to determine in particular the extent to which LU was an important factor for the distribution of common species.Methods: Based on a logistic regression model and variation partitioning being applied to each plant species, we evaluated the partial deviance by six LU types, four climatic types and three topographic and geological factors for 647 plant species at 14,412 sites in Japan.Results: The effect of LU was significant for species present at multiple sites. Of the six LU types, secondary vegetation and plantation were the most important factors determining species distribution for many species.Conclusions: Our results suggest that distribution of the common species is largely affected by LU on macroscale. The design of LU relating to secondary vegetation and plantations will thus be important in determining changes in the vegetation composition within Japan.

What factors determine the distribution of a species is a central question in ecology and conservation biology. In general, the distribution of plant species is assumed to be controlled by dispersal or environmentally controlled recruitment. For plant species which are critically dependent on mycorrhizal symbionts for germination and seedling establishment, specificity in mycorrhizal associations and availability of suitable mycorrhizal fungi can be expected to have a major impact on successful colonization and establishment and thus ultimately on a species distribution. We combined seed germination experiments with soil analyses and fungal assessments using 454 amplicon pyrosequencing to test the relative importance of dispersal limitation, mycorrhizal availability and local growth conditions on the distribution of the orchid species Liparis loeselii, which, despite being widely distributed, is rare and endangered in Europe. We compared local soil conditions, seed germination and mycorrhizal availability in the soil between locations in northern Belgium and France where L.loeselii occurs naturally and locations where conditions appear suitable, but where adults of the species are absent. Our results indicated that mycorrhizal communities associating with L.loeselii varied among sites and plant life cycle stages, but the observed variations did not affect seed germination, which occurred regardless of current L.loeselii presence and was significantly affected by soil moisture content. These results indicate that L.loeselii is a mycorrhizal generalist capable of opportunistically associating with a variety of fungal partners to induce seed germination. They also indicate that availability of fungal associates is not necessarily the determining factor driving the distribution of mycorrhizal plant species.

基于影响植物功能型分布的6个气候变量:年均降水量、气温年较差、最冷月温度、最暖月温度、大于5℃积温和湿润指数,结合蒙古栎地理分布资料,根据最大熵模型和各气候变量对蒙古栎地理分布的贡献,确定了影响蒙古栎地理分布的主导气候因子,即年均降水量、气温年较差、大于5℃积温和最暖月温度;利用模拟的蒙古栎地理分布概率与主导气候因子的关系给出了各主导气候因子的阈值,即年均降水量330-910 mm、气温年较差大于29℃、大于5℃有效积温为1200-3500℃·d、最暖月温度为17-26℃。;Relationship between plant species distribution and climate is always one of the most important issues in the ecology study. Plant species distribution at regional scale is largely controlled by climate. The dominant climatic factors influencing plant species distribution can be obtained by the relationship between climate and plant species distribution. And the dominant climatic factors are very important for revealing the reason of the formation of plant species distribution, determining the appropriate distribution zone of plant species and evaluating the responses of plant species to climate change. <em>Quercus</em> <em>mongolica</em> is the dominant tree of deciduous broad-leaved forest, conifer-broadleaved mixed forest in the temperate region of China. In order to provide the scientific support for <em>Q. mongolica</em> forest management and countermeasures to cope with future climate change in China, we have to make sure what the dominant climatic factors of its distribution are. But studies in this area are so few that restrict the understanding of the response to climate change and <em>Q. mongolica</em> forest scientific operation. Thus, the potential distribution of <em>Q.</em> <em>mongolica</em> in China and its relationship with climatic factors were studied in this paper. Based on the geographical distribution data of <em>Q.</em> <em>mongolica</em> and six climatic variables potentially controlling plant functional types' distribution including annual precipitation (<em>P</em>), annual range of monthly mean temperature (DTY), temperature of the coldest month (<em>T_c</em>), temperature of the warmest month (<em>T_w</em>), accumulated temperature of not less than 5℃ (GDD₅) and moisture index (MI), and their contribution to geographical distribution of <em>Q. mongolica</em> from the maximum entropy (Maxent) model. The area under the ROC curve (AUC) was used to evaluate the accuracy of model prediction. The AUC value reached 0.932, and the high value indicated predictive accuracy of model achieved the Excellent level. Combined with the contribution of each climatic factor as mentioned above, four dominant climatic factors controlling <em>Q.</em> <em>mongolica</em> distribution were determined, including annual precipitation (<em>P</em>), annual range of monthly mean temperature (DTY), temperature of the warmest month (<em>T_w</em>) and accumulated temperature of not less than 5℃ (GDD₅). Thus, a relationship between the geographical distribution of <em>Q.</em> <em>mongolica</em> and dominant climatic variables was reconstructed. The thresholds of four dominant climatic factors were given by the relationship between the geographical distribution probability of <em>Q.</em> <em>mongolica</em> and dominant climatic factors, i.e. 330mm≤<em>P</em>≤910mm, DTY≥29℃, 1200℃·d≤GDD₅≤3500℃·d, 17℃≤<em>T_w</em> ≤26℃. Then the potential distribution of <em>Q.</em> <em>mongolica</em> in China was given by the ArcGIS spatial analysis technique. The potential distribution area of <em>Q.</em> <em>mongolica</em> included Heilongjiang province, Jilin province, Liaoning province, eastern Inner Mongolia autonomous region, Beijing, Tianjin, north-central of Hebei province, central part of Shandong province, most parts of Shanxi province and northeast of Shaanxi province. The total area covered 1002 points of the 1013 distributed points of the actual distribution of <em>Q.</em> <em>mongolica</em>. The simulation accuracy was more than 98%, indicating that the simulated distribution of <em>Q. mongolica</em> was very coincidence with the actual distribution. The results might provide important basis for making scientific management of <em>Q. mongolica</em> forest and developing the countermeasures to deal with future climatic change.

Soil carbon content along a rainfall gradient and inhibition of germination: a potential mechanism for regulating distribution of Plantago coronopus

Gravelly pavement herbfields are a groundwater-dependant vegetation type; water composition and supply are hypothesised to be a crucial factor affecting the distribution of plant species in the community. We described the relationship between plant species distribution in pavements and the spatial and temporal availability and composition of water. Water flows into pavements varied through the growing season, as did lateral spread of water, and its permanency. Furthermore, the distribution of dominant pavement plant species was associated with moisture. Oreobolus pumilio (Cyperaceae) was significantly negatively associated, whilst Psychrophila introloba (Ranunculaceae) was significantly positively associated, with persistent moisture. The chemical composition of water changed whilst transiting through pavements, with loss of dissolved CO2 and an increase in pH likely due to strong CO2 evasion. When compared with other hydrologic units across the landscape, the chemical composition of pavement waters was between that of groundwater and peatlands, corresponding to their physical position in the landscape. These results have implications for the conservation of the gravelly pavement herbfield community. With climate change, reductions in water availability threatens the persistence of key hydrophilic species given their strong association with moisture. Reductions in areal extent, as well as re-organisation of the plant community, could be expected.

The distribution of plants along environmental gradients is constrained by abiotic and biotic factors. Cumulative evidence attests of the impact of biotic factors on plant distributions, but only few studies discuss the role of belowground communities. Soil fungi, in particular, are thought to play an important role in how plant species assemble locally into communities. We first review existing evidence, and then test the effect of the number of soil fungal operational taxonomic units (OTUs) on plant species distributions using a recently collected dataset of plant and metagenomic information on soil fungi in the Western Swiss Alps. Using species distribution models (SDMs), we investigated whether the distribution of individual plant species is correlated to the number of OTUs of two important soil fungal classes known to interact with plants: the Glomeromycetes, that are obligatory symbionts of plants, and the Agaricomycetes, that may be facultative plant symbionts, pathogens, or wood decayers. We show that including the fungal richness information in the models of plant species distributions improves predictive accuracy. Number of fungal OTUs is especially correlated to the distribution of high elevation plant species. We suggest that high elevation soil show greater variation in fungal assemblages that may in turn impact plant turnover among communities. We finally discuss how to move beyond correlative analyses, through the design of field experiments manipulating plant and fungal communities along environmental gradients.

Prediction of climate warming impacts on plant species could be more complex than expected. Evidence from a case study in the Himalaya

Relationship between topography and the distribution of matorral plant species in the Saharan Atlas: Case of Djebel Amour, Algeria

The distribution of plant species and relationships between species and soil factors in the east central part of Gurbantunggut Desert was studied to provide more insight into the flora and determine differences in vegetation across various parts of the desert. Two-way Cluster Analysis showed that the vegetation in the area could be divided into three groups, the first group was dominated by the shrub species, Ephedra przewalskii and the grass species, Carex physodes mainly in areas of flat grounds and gentle slopes; the second group was dominated by C. physodes, Artemisia songorica and A. xerophytica mainly on the slope of sand dunes and the third group was dominated by the shrub species, Haloxylon persicum mainly on the top of sand dunes. There was no difference in plant density between Groups 1 and 2 but there was a significant decrease in Group 3. Soil water under vegetation Group 3 was much lower than that in the other two groups at all soil depths. The EC, organic matter, total P and soluble Na, Ca and Mg varied very similarly with soil water. Canonical correspondence analysis (CCA) satisfactorily assessed the species-soil relations in the area. The distribution of plant species was strongly correlated with the soil factors of water content, organic matter, EC and nutrients. The variations in species occurrence explained by the three CCA axes were about 70%, indicating that some explanatory site variables may exist outside our studied parameters. Soil texture is suggested to be included in future studies to improve the explanation of CCA.

BackgroundThe dataset presented in the current study contains information regarding alien vascular plant species found in the Middle Volga Region (South-East of the European part of Russia). The dataset overall includes 413 species belonging to 247 genera and 67 families. The described dataset is based on the data published during floristic studies from 1851 to 2019. The dataset does not include alien vascular plant species that have presently disappeared from the territory of the region. It contains a total of 7,782 records of occurrences, extracted from the Salix system of information and analytics, developed in the Institute of Ecology of the Volga River Basin of the Russian Academy of Sciences.New informationA total of 7,782 records were published on the occurrence of alien vascular plants in the Middle Volga Region. Each entry includes information regarding the place of occurrence of the alien plant species, the year of occurrence, the person who recorded the alien plant and who identified it, status of the species (introduced or invasive), link to the herbarium, which contains the specimen and the literary source. If it were impossible to establish the names of the persons who collected the samples and (or) their identification in the identifiedBy and recordedBy fields, the names of the authors of the publication given in the associatedReferences field were entered. The presented dataset supplements the information on the distribution of alien plant species in the whole European part of Russia and specifies the places of their findings in the Middle Volga Region.

Zaraninge is a former forest reserve which is now included as part of the Saadani National Park in Bagamoyo District Coast Region. The influence of soil mineral nutrients (N, P, K, Mg and Na) on the pattern of plant species distributions was determined, and transect method was used for data collection. Plant species composition and abundance followed variation in soil nutrient gradients within Zaraninge Forest. Canonical correspondence analysis of soil and plant data showed that calcium, magnesium and phosphorus were the mineral nutrients that significantly influenced the distribution plant species (P &lt; 0.05) while other nutrients had no significant effects. Data from this study provide evidence of the existing variation in soil nutrient saturation gradients to which plant species distribution responds within the forest. A successful conservation of Zaraninge Forest biodiversity requires protecting the soil which is the necessary habitat for the plant species.

Fencing facility affects plant species and soil organic carbon in temperate steppes

Medicinal plants are the integral part of the variety of cultures in Ethiopia and have been used over many centuries. Hence, the aim of this study is to document the medicinal plants in the natural vegetation and home gardens in Abaya district, Borana Zone, Oromia National Regional State, Ethiopia. Forty eight traditional healers were selected to collect data on management of medicinal plants using semi-structured interview, group discussion, and field observation. The distribution of plant species in the study areas was surveyed. Forty three plant species were documented as having medicinal value: (21 (48.8%)) were Shrubs, (13 (30.3%)) herbs, and (9 (20.9%)) trees. The root (17 (39.5%)) was the most commonly used plant part followed by leaf (13 (30.2%)), fruits (7 (16.3%)) and stem (6 (14.0%)). Agricultural expansion (24.4%) in the area was found to be the main threat for medicinal plants followed by fire wood collection (18.8%). Peoples' culture and spiritual beliefs somehow helped in the conservation of medicinal plants. Traditional healers still depend largely on naturally growing plant species and the important medicinal plants are under threat. The documented medicinal plants can serve as a basis for further studies on phytochemical and pharmacological studies.

New England salt marshes provide many services to humans and the environment, but these landscapes are threatened by drivers such as sea level rise. Mapping the distribution of salt marsh plant species can help resource managers better monitor these ecosystems. Because salt marsh species often have spatial distributions that change over horizontal distances of less than a meter, accurately mapping this type of vegetation requires the use of high-spatial-resolution data. Previous work has proven that unoccupied aerial vehicle (UAV)-acquired imagery can provide this level of spatial resolution. However, despite many advances in remote sensing mapping methods over the last few decades, limited research focuses on which spectral band, elevation layer, and acquisition date combinations produce the most accurate species classification mappings from UAV imagery within salt marsh landscapes. Thus, our work classified and assessed various combinations of these characteristics of UAV imagery for mapping the distribution of plant species within these ecosystems. The results revealed that red, green, and near-infrared camera image band composites produced more accurate image classifications than true-color camera-band composites. The addition of an elevation layer within image composites further improved classification accuracies, particularly between species with similar spectral characteristics, such as two forms of dominant salt marsh cord grasses (Spartina alterniflora) that live at different elevations from each other. Finer assessments of misclassifications between other plant species pairs provided us with additional insights into the dynamics of why classification total accuracies differed between assessed image composites. The results also suggest that seasonality can significantly affect classification accuracies. The methods and findings utilized in this study may provide resource managers with increased precision in detecting otherwise subtle changes in vegetation patterns over time that can inform future management strategies.

Numerous plant colonizations have been putatively attributed to deer, based on plant species traits, fur brushing or dung analyses. But, in woodlands, direct links between the expansion of zoochorous plant species and ungulate presence have seldom been reported. Based on coupled floristic and browsing surveys, repeated in time, we analysed the causes of the spatio-temporal progression of the epizoochorous species Cynoglossum germanicum over 30 years in a network covering an 11000 ha forested area in north-eastern France. In this area, deer populations reached a peak in the 1970s, then were reduced in order to meet forest management requirements. Although initially rare and protected locally, C. germanicum has displayed an unexpected fast colonization rate during the last few decades but only in the northern part of the forest, which previously had the highest animal populations. Absent in the initial 1976 survey, C. germanicum occurred in 8% of the plots in 1981, then 46% in 2006. Logistic regression models revealed that the probability of occurrence of C. germanicum in 2006 increased not only with light indicator values, in accordance with its ecological requirements, but also with past deer browsing pressure. This result provides direct evidence of long-lasting impacts of deer populations on plant species distribution. Combining two complementary traits, animal transport and herbivory avoidance, C. germanicum benefited from epizoochorous dispersal and, once established, was protected from deer browsing by the presence of toxic proteins in its tissues. Due to the triggering role of ungulates, this species switched from the status of rare to that of colonizer within only a few decades.