Similar Ecological Environments Research Articles

Coupling of leaf economic and hydraulic traits of desert plants of different life forms in the Ebinur Lake Basin

The functional traits of leaves and their internal trade-offs have been the focus of ecologists as a powerful basis for revealing plant physiology and function, and ecological strategies. The consistency of the coupled relationship between leaf economic traits and hydraulic traits among trees, shrubs, and herbs in similar ecological environments has seldom been systematically explored. We explored coupling in desert plants of different life forms and their response to the soil environment in two tree species (Populus euphratica Oliv. and Haloxylon ammodendron (C. A. Mey.) Bunge)), the shrub species (Nitraria tangutorum Bobrov and Halimodendron halodendron (Pall.) Dum. Cours.), and herbaceous species (Alhagi sparsifolia Shap. and Apocynum venetum L.) in the transition zone of the desert in the Ebinur Lake Basin, Xinjiang, China. Leaf and soil samples were collected to determine plant leaf economic traits, hydraulic traits, and soil factors. Regarding leaf economic traits, trees had higher in leaf mass per area and leaf thickness (LT). The leaf nitrogen and phosphorus contents were higher in shurbs than those in trees and herbs. Regarding hydraulic traits, shrubs had higher palisade parenchyma thickness (PT) and vein density (VD), whereas herbs had higher stomatal length (SL), spongy parenchyma thickness (ST), and leaf water potential (Ψ). In herbs, SL, ST, and Ψ had advantages, whereas PT/ST was the lowest. This study revealed an association between leaf economic and hydraulic traits in plants of different life forms in a similar ecological environment and provides a scientific basis for plant conservation strategies and ecosystem services value assessment and use in arid zones.

Combining genetic and environmental data to map and model regions of provenance for silver fir (Abies alba Mill.) in Italy

Regions of provenance for forest reproductive materials are the basis for wise use of forest resources in a changing climate. In this work a modelling framework is proposed for silver fir (Abies alba Mill.) in Italy where genetic clusters described by nuclear microsatellites were combined with high-resolution climatic data. When the genetic clusters were too large or had an uncertain ecological niche expression, an additional subregion division-was evaluated according to a climatic assessment. Subsequently each genecological group (Region of Provenance, RoP) was projected in geographic space separately using species distribution modelling (SDM) procedure under current (1991–2020) and a future climate scenario derived from the 6th assessment report for the period 2041–2070. The final division into nine RoPs was able to explain 77.41% of the total climatic variance, a good trade-off between statistical significance and practical usability. The modelling steps then showed a large degree of ecological overlap between RoPs with some of them occurring in similar ecological environments but characterized by a different genetic structure. When projected at the continental scale, the Italian RoPs were found to be suitable for almost all the current European range of silver fir, with potential expansion in Nordic countries in the future, beyond the current distribution range. The study showed that the combination of genetic and ecological data can be a robust way to proceed in areas where a strong genetic differentiation between populations occurs, such as in Italy. New markers such as SNPs can then be used to detect adaptive traits and drive the selection of provenances for common garden experiments in areas where the SDM modelscurrently extrapolate potential sites outside the current natural range.

Population Genomics Unravels the Characteristic Relationship between Introgression and Geographical Distribution in Upland Cotton

Introgression is an important driver of new genetic variation that increases species and genetic diversity. However, the relationship between introgression and geographic distribution of upland cotton is still unclear. Herein, we explored geographically comprehensive genomic data based on 890 upland cotton accessions to decipher the degree of introgression between different geographic distributions and its effect on selection and fiber quality. We found introgression intervals to exist across different geographic distributions. Introgression is affected by the similarity of the environment in which they live, and those with similar ecological environments tend to share the same introgression area. Introgression is affected by artificial selection. A genome-wide association study (GWAS) meta-analysis was performed with 6 fiber traits and identified 261 quantitative trait loci (QTLs). We found that 67 QTLs had introgression signals, and the genome interval size was 118.81 Mb, while 123 QTLs had selection signals, and the genomic interval was 28.38 Mb. These results provide insights into the population-scaled introgression landscape, suggesting that introgression contributed to the cotton genetic improvement, which provides a useful reference for studying intraspecific introgressions from different geographical distributions in other species.

Toward the carbon neutrality: Forest carbon sinks and its spatial spillover effect in China

Developing forest carbon sinks is very important for China to achieve carbon neutrality. However, the forest resource distribution is spatially dependent, and forest carbon sinks cannot be sufficiently developed in an isolated pattern. Therefore, based on the spatial panel data of 30 provinces in China from 2003 to 2019, this study establishes a spatial econometric model and identifies transregional spillover effects of forest carbon sinks. The results show that the forest carbon sinks do have transregional spatial correlation characteristics. In addition to similar ecological environment factors in adjacent regions, the forest carbon sinks are closely related to the economic development structure and related policies. The proportion of the forest area and urbanization level are positively correlated with the forest carbon sinks in the region and neighboring regions, but the amount of deforestation and transport infrastructure level has a negative effect. Implementing carbon trading pilot programs in one region can promote the development of its local forest carbon sinks, but it has a negative spillover effect on the other regions. Furthermore, environmental regulation has a positive spillover effect on neighboring regions, whereas forestry production efficiency has a negative spillover effect. Some policy implications are proposed according to the results and China's realistic characteristics.

Genetic Diversity of Global Faba Bean Germplasm Resources Based on the 130K TNGS Genotyping Platform

Novel germplasm resources are the key to crop breeding, with their genetic diversity and population structure analysis being highly significant for future faba bean breeding. We genotyped 410 global faba bean accessions using the 130K targeted next-generation sequencing (TNGS) genotyping platform, resulting in a total of 38,111 high-quality SNP loci by high-standard filtering. We found the polymorphism information content (PIC) and Nei’s gene diversity were 0.0905–0.3750 and 0.0950–0.5000, with averages of 0.2471 and 0.3035, respectively. After evaluating the genetic diversity of 410 accessions using Nei’s gene diversity and PIC, on the basis of their geographical origin (continent) and structure-analysis-inferred subpopulations, we found that the faba bean accessions from Asia (except China) and Europe had rich genetic diversity, while those from the winter sowing area of China were low. The 410 faba bean accessions were divided into four subpopulations according to population structure analysis and clustering analysis based on Nei’s (1972) genetic distance using the neighbor-joining (NJ) method. However, the same subpopulation contained materials from different geographical origins, thereby indicating that the gene flow or introgression occurred among the accessions. Results from NJ clustering based on shared allele genetic distance indicated that the 410 accessions were divided into three groups according to their dissemination routes. The genetic diversity analysis results demonstrated that the genetic relationships among the faba bean groups with similar ecological environments and geographic origins in neighboring regions or countries were closer and frequently found within the same group, while genetic variation among individuals was the main source of their total genetic variation.

Soil C:N:P Stoichiometric Characteristics and Soil Quality Evaluation under Different Restoration Modes in the Loess Region of Northern Shaanxi Province

Vegetation restoration is essential for the stability of the ecological system structure and function in the loess region of North Shaanxi Province. Natural and artificial restoration are the primary modes for vegetation recovery and soil quality improvement in this region. In this study, two adjacent watersheds with similar ecological environment conditions but different restoration modes were selected for research; one watershed is restored naturally (He Gou watershed), and the other is restored artificially (Chai Gou watershed). According to the study of soil stoichiometric characteristics and soil quality after the vegetation restoration in these two watersheds, the results showed: (1) Compared with the natural restoration, artificial restoration was more effective in increasing the content of soil organic carbon and total nitrogen, however, the total phosphorus content of the soil in the natural restoration mode was higher than that in the artificial restoration mode. (2) The ratios of soil C:N, C:P, and N:P showed a decreasing trend with the increase of soil depth at these two restoration modes. (3) In the 0–60 cm soil layer, the soil quality under the artificial restoration mode was better than that of the natural restoration, especially for the soil layer beneath 20 cm. (4) The minimal data set on the soil quality evaluation in the study area included soil organic carbon, capillary water holding quantity, available potassium, soil water content and available phosphorus. It showed a linear relation with the total index data set (y = 0.829x + 0.058, R2 = 0.76) and can reflect the soil quality more sensitively than the total indicator data set.

Genome-wide identification of quantitative trait loci for morpho-agronomic and yield-related traits in foxtail millet (Setaria italica) across multi-environments

Foxtail millet (Setaria italica) is an ideal model of genetic system for functional genomics of the Panicoideae crop. Identification of QTL responsible for morpho-agronomic and yield-related traits facilitates dissection of genetic control and breeding in cereal crops. Here, based on a Yugu1 × Longgu7 RIL population and genome-wide resequencing data, an updated linkage map harboring 2297 bin and 74 SSR markers was constructed, spanning 1315.1 cM with an average distance of 0.56 cM between adjacent markers. A total of 221 QTL for 17 morpho-agronomic and yield-related traits explaining 5.5 ~ 36% of phenotypic variation were identified across multi-environments. Of these, 109 QTL were detected in two to nine environments, including the most stable qLMS6.1 harboring a promising candidate gene Seita.6G250500, of which 70 were repeatedly identified in different trials in the same geographic location, suggesting that foxtail millet has more identical genetic modules under the similar ecological environment. One hundred-thirty QTL with overlapping intervals formed 22 QTL clusters. Furthermore, six superior recombinant inbred lines, RIL35, RIL48, RIL77, RIL80, RIL115 and RIL125 with transgressive inheritance and enrichment of favorable alleles in plant height, tiller, panicle morphology and yield related-traits were screened by hierarchical cluster. These identified QTL, QTL clusters and superior lines lay ground for further gene-trait association studies and breeding practice in foxtail millet.

“Mushrooms (and a cow) are A Means of Survival for Us”: Dissimilar Ethnomycological Perspectives among Hutsuls and Romanians Living Across The Ukrainian-Romanian Border

Sustainable forest management highlights the multipurpose use of all forest resources, including the use of wild mushrooms, by a variety of forest users and especially for rural livelihoods. To achieve sustainable forest management, among others, decision-makers and forest managers need to identify the important elements for the livelihoods of local communities dependent on forests. Therefore, our aim is to analyse the importance of contemporary use of wild mushrooms for daily livelihoods in rural areas of the Carpathian Mountains by comparing two ethnic groups, Hutsuls and Romanians, living in a similar ecological environment and formerly belonging to the historical region of Bukovina, but currently split by the border between Ukraine and Romania which have different governments and economic situations. One hundred and twenty-one face-to-face semi-structured interviews were conducted in the summers of 2018 and 2019. We compared the Traditional Ecological Knowledge (TEK) of Romanians and Hutsuls living, respectively, in lowlands and mountain areas on both sides of the border. Our results demonstrated the homogenous use of mushroom species for cultural purposes (e.g. ritual foods). Yet, we detected a remarkable difference in the role mushrooms play in providing income: Hutsuls in Ukraine use forest products as a main (rarely additional) source of income, while Romanian Hutsuls use them solely as additional income. Romanians on both sides considered mushrooms mainly as food and did not sell them (probably due in part to less abundance in the area). We also documented the fear of local residents that forest management and protected areas could suppress the right to collect wild mushrooms. The use of mushrooms is an important aspect of local TEK and needs to be considered as a part of sustainable forest management and as a means of poverty reduction in the region.

Quantitative analysis of total content differentiation and driving factors of phenolic acids in Angelicae Sinensis Radix of Gansu Dao-di herbs from perspective of geographical space

Dao-di herbs, produced in a specific region and screened through long-term clinical application, is characterized by high stable quality, good efficacy, and high popularity. With favorable climate conditions, Gansu gives birth to the Dao-di herbs Angelicae Sinensis Radix which is widely used in clinical practice, and multiple regions in Gansu, with similar ecological environment produce Angelicae Sinensis Radix. In this study, the spatial correlation and difference of phenolic acid content in Angelicae Sinensis Radix from Dao-di producing areas, emerging producing areas, and emerging planting areas in Gansu were analyzed based on ArcGIS to explore the "quality(chemical type)" characteristics of genuine Angelicae Sinensis Radix. Moreover, spatial distribution law and main driving factors of the total phenolic acid content in Angelicae Sinensis Radix in Gansu were analyzed based on geodetecctor. This study is expected to lay a basis for Dao-di research and production regionalization of Angelicae Sinensis Radix.

Functional gene assessment of bread wheat: breeding implications in Ningxia Province

BackgroundThe overall genetic distribution and divergence of cloned genes among bread wheat varieties that have occurred during the breeding process over the past few decades in Ningxia Province, China, are poorly understood. Here, we report the genetic diversities of 44 important genes related to grain yield, quality, adaptation and resistance in 121 Ningxia and 86 introduced wheat cultivars and advanced lines.ResultsThe population structure indicated characteristics of genetic components of Ningxia wheat, including landraces of particular genetic resources, introduced varieties with rich genetic diversities and modern cultivars in different periods. Analysis of allele frequencies showed that the dwarfing alleles Rht-B1b at Rht-B1 and Rht-D1b at Rht-D1, 1BL/1RS translocation, Hap-1 at GW2-6B and Hap-H at Sus2-2B are very frequently present in modern Ningxia cultivars and in introduced varieties from other regions but absent in landraces. This indicates that the introduced wheat germplasm with numerous beneficial genes is vital for broadening the genetic diversity of Ningxia wheat varieties. Large population differentiation between modern cultivars and landraces has occurred in adaptation genes. Founder parents carry excellent allele combinations of important genes, with a higher number of favorable alleles than modern cultivars. Gene flow analysis showed that six founder parents have greatly contributed to breeding improvement in Ningxia Province, particularly Zhou 8425B, for yield-related genes.ConclusionsVarieties introduced from other regions with rich genetic diversity and landraces with well-adapted genetic resources have been applied to improve modern cultivars. Founder parents, particularly Zhou 8425B, for yield-related genes have contributed greatly to wheat breeding improvement in Ningxia Province. These findings will greatly benefit bread wheat breeding in Ningxia Province as well as other areas with similar ecological environments.

Controls on myxomycete species and species assemblages

This paper uses data from previous worldwide myxomycete surveys to determine the controls on the occurrence of myxomycete species, and on species assemblages. The main findings are as follows. The effect of substrate pH can be modelled, in that each species has a preferred pH value relative to the mean of a survey; errors from the model are 0.2 pH units. The substrate physical properties, evaluated by subjective hardness, showed no correlation with pH measurements. Hence, myxomycete species seem to have distinct ecological niches in substrate, with preferred pH and preferred physical properties. Comparison of the species found from the liana stem substrate shows that the species association does not change within angiosperm forests. Further, the species association is the same as that found in other angiosperm litter substrates: twigs on trees or on the ground, and leaves. This and a previous finding are consistent with similar ecological environments around the world having the same myxomycete species association within sampling error. In mixed angiosperm forests around the world the pH of un-decayed wood is ~4.9, and for decayed wood and tree litter is ~6.5 in tropical latitudes, and ~5.5 at 35° latitude, so on decaying the change in pH varies with latitude.

Comparative study on distribution of Callicarpa nudiflora by different regionalization methods

This article is based on basic data such as field surveys and literature surveys, contrasting and analyzing the distribution of Callicarpa nudiflora by different zoning methods, different data sources, and different spatial scales. The results showed that there were certain differences in the distribution results obtained by using different methods, such as qualitative description, similar ecological environment, and niche model, to divide the distribution of the C. nudiflora, but all of them could reflect the distribution of C. nudiflora to different degrees. Among them, the qualitative description division method has certain advantages in macro guidance in a large scale. The distribution range obtained by the ecological environment similar division method is wider than that obtained by applying the qualitative description method and the niche model method. The results of the zoning of the distribution of the C. nudiflora obtained from different data sources were different. The number and representativeness of the survey data have an impact on the zoning results. Through the analysis of the distribution of different spatial scales, the ecological factors and contribution rates that affect the distribution of C. nudiflora are different in China and in the world. The comprehensive multi-source data analysis showed that C. nudiflora mainly distributed in southern coastal provinces such as Hainan, Guangdong, Guangxi and Fujian in China, and also in Jiangxi, Guizhou, Yunnan, Sichuan, Chongqing, Hunan, Gansu, Taiwan and other provinces. Globally, C. nudiflora are suitable for distribution in Southeast Asia, such as China, Vietnam, Laos, Myanmar, India, etc. There are also potential distribution areas in the southern United States and Mexico.

Comparative study on distribution of Polygoni Multiflori Radix based on different methods

In recent years,with deepening research on the division of traditional Chinese medicine,the application of new technologies and new methods have provided support for the division of traditional Chinese medicine. Some relevant scholars have carried out researches on the distribution of some Chinese herbal medicines based on different methods. In this paper,for the same kind of Chinese herbal medicine under different data conditions,we studied the distribution of Polygoni Multiflori Radix by different methods such as qualitative description,similar ecological environment and niche model,and compared the similarities and differences between the distribution results of the same Chinese medicine resources based on different data and methods. The results showed that with the restriction of the researcher's understanding of Chinese herbal medicines and related background data,the zoning results were also in various forms,and there might also be some differences between different zoning results. But in the macroscopic layer,they could reflect the distribution range of Chinese herbal medicines,and they have certain application values to some extent. For example,the study focused on the ancient and modern data and found that with the continuous enrichment of data and information,the understanding of the distribution of Polygoni Multiflori Radix gradually expanded from the southeast coast to the central and southwestern regions to the northwest.But the number of Polygoni Multiflori Radix in the western and northern regions is relatively small than the southeastern regions. The results of relevant zoning can provide scientific basis for carrying out the rational cultivation of Polygoni Multiflori Radix.

Tolerance of citrus genotypes towards Pseudocercospora leaf and fruit spot disease in western highlands zone of Cameroon

Pseudocercospora leaf and fruit spot disease (PLFSD) is a serious production constraint to citrus growers in Africa and Yemen. An assessment of the disease was carried out in the location of Foumbot, western highlands of Cameroon characterised by monomodal rainfall patterns, low temperatures and high relative humidity. The plot was set up in a complete randomised block design with eight replicates, with each comprising one stand of the 15 genotypes. The assessment was carried out in 2016, on 15 genotypes plot established in 2002, and was based on the disease impact on leaves and fruits. The impact of the disease was recorded on a scale of one to five, where one represented organ with 0% disease, and five the organs with more than 75%. Vegetative development of citrus tree attributes such as tree height, canopy mean diameter, scion and rootstock circumference were also recorded. Results showed that six genotypes presented the lowest disease severity. These are: Bearss Lime (1.75 ± 0.50), Obala Tangerine (2.00 ± 0.0), Sans Epines Lime (2.00 ± 0.53), Ponkan Yoshida (2.13 ± 0.35), Emperor Tangerine (2.43 ± 0.78) and Beauty Tangerine (2.57 ± 0.78). Ponkan Yoshida and Sans Epines Lime, that also presented the best morphological parameters, can be qualified as best candidates for their tolerance to PLFSD under these ecological conditions. Despite their morphological and tolerance to PLFSD, Bearss Lime showed 50% dead stands. Further investigations on opportune pests and diseases affecting citrus should be carried out to assess their contribution on these, on similar ecological environment.

Incorporating habitat suitability into community projections: Ant responses to climate change in the Australian Wet Tropics

AbstractAimStudies of climate change impacts on animal distributions typically consider only the direct impacts of a changing climate, under the assumption that future areas of suitable climate will otherwise remain ecologically suitable. Here we assess both the direct and indirect impacts of climate change on rain forest ant communities, where substantial shifts are projected to occur for both climate and habitat types.LocationAustralian Wet Tropics (AWT).MethodsGeneralized Dissimilarity Modelling was used to model turnover in the composition of ~300 rain forest ant species sampled at 150 sites across six mountains spanning five degrees of latitude. Ants were sampled within the leaf litter, on the litter surface and on tree trunks. By modelling the rate of turnover among sites, we determined the current effective area of similar ecological environments (SEE) for ant communities and consequently the expected change in species persistence when habitat shifts under two climate projections for the years 2035, 2055 and 2085. We compared results when SEE considered only the direct effects of a changing climate, with those when changes in habitat were also included.ResultsThe rain forest ant communities modelled will lose a substantial proportion of SEE under both climate change scenarios. Under combined direct (changes in climate) and indirect (changes in rain forest habitat) impacts of climate change, >90% of the communities in the region were predicted to lose up to half their similar habitats compared with 50%–60% when only considering direct climate change impacts. The highest risk of reduction in area of SEE is projected in drier inland areas of the AWT, where profound compositional turnover is linked to dramatic changes in rain forest vegetation, including extensive conversion into savanna.Main conclusionsOur findings emphasize the importance of incorporating habitat suitability into future projections of species turnover under a changing climate, particularly for habitats where vegetation structure is projected to undergo profound change.

Zika virus infection in Malaysia: an epidemiological, clinical and virological analysis

BackgroundA major outbreak of the Zika virus (ZIKV) has been reported in Brazil in 2015. Since then, it spread further to other countries in the Americas and resulted in declaration of the Public Health Emergency of International Concern (PHEIC) by World Health Organization. In 2016, Singapore reported its first minor ZIKV epidemic. Malaysia shares similar ecological environment as Brazil and Singapore which may also favor ZIKV transmission. However, no ZIKV outbreak has been reported in Malaysia to date. This study aimed to discuss all confirmed ZIKV cases captured under Malaysia ZIKV surveillance system after declaration of the PHEIC; and explore why Malaysia did not suffer a similar ZIKV outbreak as the other two countries.MethodsThis was an observational study reviewing all confirmed ZIKV cases detected in Malaysia through the ZIKV clinical surveillance and Flavivirus laboratory surveillance between June 2015 and December 2017. All basic demographic characteristics, co-morbidities, clinical, laboratory and outcome data of the confirmed ZIKV cases were collected from the source documents.ResultsOnly eight out of 4043 cases tested positive for ZIKV infection during that period. The median age of infected patients was 48.6 years and majority was Chinese. Two of the subjects were pregnant. The median interval between the onset of disease and the first detection of ZIKV Ribonucleic Acid (RNA) in body fluid was 3 days. Six cases had ZIKV RNA detected in both serum and urine samples. Phylogenetic analysis suggests that isolates from the 7 cases of ZIKV infection came from two clusters, both of which were local circulating strains.ConclusionDespite similar ecological background characteristics, Malaysia was not as affected by the recent ZIKV outbreak compared to Brazil and Singapore. This could be related to pre-existing immunity against ZIKV in this population, which developed after the first introduction of the ZIKV in Malaysia decades ago. A serosurvey to determine the seroprevalence of ZIKV in Malaysia was carried out in 2017. The differences in circulating ZIKV strains could be another reason as to why Malaysia seemed to be protected from an outbreak.

Spatial predictions of the permanent wilting point in arid and semi-arid regions of Northeast China

The permanent wilting point (PWP) is the minimal point of soil moisture a plant requires not to wilt. If moisture decreases to this, or any lower point, a plant wilts, and can no longer recover its turgidity when placed in a saturated atmosphere for 12 h. The PWP is an essential physical property that has a powerful influence on other soil properties and is important for agricultural production, including irrigation water use efficiency and crop yield. However, there are few published datasets on the PWP of cultivated land in the arid and semi-arid regions of Northeast China. Direct measurements of PWP are time-consuming and expensive; therefore, the aim of this study was to evaluate how environmental variables could be used in spatial predictions of PWP in an arid and semi-arid region based on boosted regression tree (BRT) and multiple linear stepwise regression (MLSR) analyses. Seventy soil samples and nine covariates (including topography and vegetation variables) were collected and analyzed. Cross-validation procedure was used to evaluate model performance and uncertainty. Accuracy evaluation results showed that the BRT model had better predictive performance than the MLSR. PWP content decreased from the southwest to the northeast of the study area, and average values of both models were 26%. BRT and MLSR models should be compared and calibrated to obtain the best prediction effect of PWP spatial distribution in similar areas. Elevation, slope gradient, profile curvature, topographic wetness index, and land-use variables are the main environmental indicators that should be included when generating PWP maps of regions with a dry, continental climate. Such information could aid local land managers and government agencies with evaluating soil quality and water sequestration potential. In conclusion, this study could be used as a reference for predicting the hydrological parameters of the topsoil in other similar ecological environments.

Some refinements on species distribution models using tree-level National Forest Inventories for supporting forest management and marginal forest population detection

Abstract: Spatial modelling is a fundamental tool to support forest management strategies. National Forest Inventories (NFIs) provide extensive and detailed data for spatial analysis. In this study, the most recent Italian NFI (INFC2005) was used to evaluate possible refinements on species distribution model (SDM) techniques and to derive the future scenarios for two target species (Fagus sylvatica L. and Abies alba Mill.) sharing a similar ecological environment and geographic range. A weighted SDM and a provenance distribution model (PDM) were tested, based on tree-level selection of NFI plots using species basal area as a filter. Two climate projections were analysed for 2050s according to the IPCC 5th Assessment Report (AR5). The results were evaluated as possible guidelines for management of the Italian region of the EUFGIS network, where many marginal forest populations (MaPs) are currently included as genetic conservation units (GCUs). The uncertainty of coordinates of inventory points did not affect the results of SDM. No statistical differences were found when comparing the niche realization for the two model species (ANOVA p>0.05) mainly due to spatial autocorrelation between the environmental predictors. Based on the classic SDM evaluation method (True Skill Statistic - TSS) little improvements in predictions were observed when weighting each presence/absence records, possibly due to the lack of adequate ancillary data but also to the evaluation method. A higher accuracy of predictions (TSS>0.85) was obtained when different “provenances” were modelled separately, due to the reduction in the “background noise”. We showed that for classical SDM, the prevalence of certain ecological features of some locations may drive algorithms to produce coarse averaged predictions. Provenance distribution modelling may represent a valuable step forward in spatial analysis, particularly for the detection of marginal peripheral populations. The exact spatial co-ordinates of plots and additional information on site quality (e.g., stand age, site index, etc.) in NFI data could greatly help in better weighting presence/absence data and properly test the new evaluation methods.

Effect of Planting Date on Accumulated Temperature and Maize Growth under Mulched Drip Irrigation in a Middle-Latitude Area with Frequent Chilling Injury

Given that chilling injury, which involves late spring cold and early autumn freezing, significantly affects maize growth in middle-latitude cold areas, a highly efficient cultivation technique combining suitable planting date (PD) and mulched drip irrigation is being studied to guarantee maize production. A field experiment for medium-mature variety “Xianyu 335” was conducted in 2015 to 2016 in Chifeng, Inner Mongolia, China, to explore the effects of PD on the active accumulated temperature (AAT) distribution and maize growth under mulched drip irrigation. Based on the dates (around May 1) of late spring cold occurring in the area, four PDs were designed, namely, April 20 (MD1), May 2–3 (MD2), May 12 (MD3), and May 22 (MD4), and a non-film mulching treatment (NM-D2) was added on the second PD. Results indicated that: (1) the warming effect of film mulching effectively compensated for the lack of heat during the early stages of maize growth. Compared with that in NM-D2, the soil temperature under mulching in MD2 for the sowing–emergence and seedling stage increased by 14.3% and 7.6%, respectively, promoting maize emergence 4 days earlier and presenting 5.6% and 9.7% increases in emergence rate and grain yield, respectively; (2) the AAT reduction caused by PD delay was mainly observed in reproductive stage, which reached 96.6 °C for every 10 days of PD delay in this stage; (3) PD markedly affected maize growth process and yield, which were closely related to the chilling injury. The late spring cold slowed down the emergence or jointing for maize (under MD1 and MD2), but brought insignificant adverse effect on maize later growth and grain yield (16.1 and 15.9 Mg·ha−1, respectively). While the maize in both MD3 and MD4 treatments suffered from early autumn freezing damage at the anthesis–maturity stages, resulting in shortening in reproductive period by 4–8 days and decrease in grain yield by 11.4–17.3% compared with those in MD1 and MD2; and (4) taking the typical date (May 1) of late spring cold occurring as the starting point, the grain yield penalty reached 8.5% for every 10 days of PD delay; for every 100 °C of AAT decrease during reproductive stage, the grain yield decreased by 6.1%. The conclusions offer certain reference values for maize cultivation in the same latitude areas with similar ecological environments.

Chironomidae of the Holarctic region: a comparison of ecological and functional traits between North America and Europe

Chironomidae (Diptera) are widespread, abundant, diverse and ubiquitous, and include genera and species that are distributed across the Holarctic region. However, the geographical barriers between continents should have resulted in intraspecific population differentiation with reflection on individual biological and ecological traits. Our aim was to test for potential differences in Chironomidae species/genus and traits between the Nearctic and Palearctic regions. We compared the Chironomidae trait information gathered in two databases; one database was developed in Europe and the other in North America. Common genera and species of both databases were selected, and the common traits were adjusted into the same trait categories. Data were transformed into presence/absence and divided into Eltonian (biological/functional) and Grinnellian (ecological) traits. Common genera and common species were analyzed using Fuzzy correspondence analysis (FCA). Differences between databases occur for all trait domains. Yet, Eltonian traits showed lower level of concordance than Grinnellian traits at the species level. Different biological characteristics in the Nearctic and Palearctic regions may indicate that Chironomidae have different adaptions to similar ecological environments due to intraspecific variability or even trait plasticity.