Grasslands are recognized as the most threatened communities on the planet due to environmental and anthropogenic disturbances. In the state of Chihuahua, Mexico, native grasslands have a great ecological importance due to their wide distribution; however, studies on the current and future potential distributions of grasslands, as well as their temporal dynamics based on climatic variability, are lacking. Thus, we analysed the potential distribution of five native grasses (Bouteloua curtipendula, Bouteloua gracilis, Leptochloa dubia, Digitaria californica and Setaria macrostachya) based on climatic factors. The present data of these species were consulted at the Global Biodiversity Information Facility (GBIF) and recorded with location information: latitude and longitude. This database was complemented with presence data of the five species from previous studies. To characterize the climate niche, the values of the climatic factors at the locations of the species presence, were obtained from the WorldClim. Then, current and future potential distributions of these native species, were generated based on three climate change scenarios, based on Representative Concentration Pathways - RCP2.6, RCP4.5 and RCP6.0). Under the RCP2.6 scenario, the estimated area of S. macrostachya was 12,525.5 ha, representing 7.4% of the state. For B. gracilis, the potential areas under the RCP4.5 and RCP6.0 scenarios were 20,391.49 and 23,079.08 ha, respectively. B. curtipendula represented the smallest area, with 4.6% under the scenario RCP2.6. The distribution of grassland species in northern Mexico is mainly determined by climatic factors; as it may apply for the rest of the grassland species within this area, so those results could increase our knowledge about their potential distribution.

The growth rate of the diameter of trees is significantly correlated with their age; therefore, a growth model can be established to predict the dynamics of the population. To reveal the relationship between individual age and diameters at breast height (DBH) of D. involucrata，five populations were chosen in the largest distribution area of D. involucrata in Sichuan province. Dendrochronology and regression model was used to evaluate the distribution of the DBH and its relationship with the age, respectively. All 130 D. involucrata trees recorded in the studied plots, with the minimum DBH of 3.8 cm, and the maximum of 45.5 cm, corresponding to the minimum age of 4 years and the maximum age of 98 years. The results showed that in the first 11 DBH classes (DBH < 22 cm), the tree DBH increases relatively slowly with the growth of the age. After the 11th DBH class, the DBH class increases slowly with increasing tree age. The tree age exceeds 20 years, the increase in the DBH growth rates with tree age is similar among the five populations. The linear models were fitted to determine the regression equation for the DBH growth curve of D. involucrata, which can be well described by a parabolic model. Under normal forest stand development and growth conditions, the model can be widely applied to study the ages of individual D. involucrata.

Most soils possess a large supply of nutrients, but these reserves cannot be mobilized by plants, as they exist in a bound form. Therefore, it is need to understand mechanisms that naturally increase the acquisition of nutrients by plants. Earthworms are crucial soil engineers that play a key role in soil functioning. In this study we have estimated the impact of three factors, earthworm species, ecological group, and soil type, on the ion content of casts of Eisenia nordenskioldi, E. ventripapillata, E. nana, Lumbricus rubellus, and Aporrectodea caliginosa. Laboratory experiments were performed in microcosms on three soil types. We analyzed five water-soluble cations and six anions in the earthworm casts by capillary zone electrophoresis to determine their content in casts compared to soil. For three of the five species studied this is the first information obtained on the matter. The obtained data demonstrated that soil type has the biggest impact on the observed changes in the cast ion content, probably due to the differences in the initial concentrations and soil properties. Within each soil type, the observed effects were mostly species-specific, and the species belonging to the same ecological group (endogeic and epi-endogeic) did not have similar effects. The exposure to different earthworm species resulted in pronounced differences in the concentrations of magnesium, calcium, ammonium, and chloride, while the soil type had the highest impact on sulfate, fluoride, acetate, and sodium ions. Therefore, the terms ‘ecological group’ and ‘functional group’ are not equivalent for earthworm casts, and replacing an earthworm species with another belonging to the same ecological group may result in changes of the soil ion composition.

Rhizosphere fungal communities are of critical importance for forest health. Microbial diversity varies with forest types due to tree species. In order to examine the influence of forest types and species composition on fungal community diversity in rhizosphere soil, the field sampling was conducted in the pure and mixed forest stands of Castanopsis hystrix in a subtropical region of China. Soil samples were taken from four forest types: Castanopsis hystrix pure forests (CH), Castanopsis hystrix × Pinus elliottii mixed forests (CHPE), Castanopsis hystrix × Michelia macclurei mixed forests (CHMM), and Castanopsis hystrix × Mytilaria laosensis mixed forests (CHML), and the species composition and structure of rhizosphere fungal community were examined by using high-throughput sequencing approach for 18S rRNA genes. The results showed that the amount of OTUs (operational taxonomic units) were 288, 331, 334 and 293 in CHML, CHMM, CHPE and CH stands, respectively, and these fungal communities were affiliated with 13 phyla, 28 classes, 85 orders, 87 families, and 131 genera. The fungal diversity was greater in CHMM and CHPE stands than in CH stands. The compositions were similar in CHMM and CHPE stands while those were significantly different in CHML and CH stands. The cladograms and co-expression network analysis showed that Ascomycota, Basidiomycota, Mortierellomycota and Rozellomycota were the dominant phyla. The study results implied that mixed forests might have a high potential for improving the microbial community diversity with formation of key species of microbial taxa due to the favorable microclimate and quality of litter composition occuring in mixed forests.

We provide the first records of possible conspecific brood parasitism in the lesser whitethroat Sylvia curruca and the common linnet Linaria cannabina, two species of small passerines. In 2018 we found two unusually large clutches, one for each species (8 and 9 eggs, respectively), both containing two distinct egg morphs differing in coloration. Further detailed analysis of egg morphology and brood phenology (in the whitethroat) suggested that the eggs in each nest had been laid by different females. Surprisingly, two seemingly full sized clutches were laid in both nests, a pattern that is unusual in conspecific brood parasitism in passerines, whose nests are typically parasitized with single eggs. Alternatives to conspecific brood parasitism are therefore discussed. We argue that traditional field-based methods, when carefully used, may be sufficient to document brood parasitism recorded during occasional observations. We finally conclude that enlarged broods, resulting from conspecific brood parasitism, are probably more frequent than expected, but they may be often overlooked.