Suitable Habitat Conditions Research Articles

Nutrients, isolation and lack of grazing limit plant diversity in restored wetlands

Abstract Agricultural intensification has led to the loss of most natural wetlands from human‐dominated landscapes but, in recent decades, wetland restoration has gained traction worldwide. Restoration of suitable habitat conditions is hampered by nutrient residues from decades of high‐input farming, by continued input of nutrients from surrounding farmland and by incomplete restoration of natural hydrology. We assessed the effect of wetland restoration and disturbance (grazing) on vascular plant and bryophyte diversity in restored wetlands in Denmark at plot and landscape scales. Compared to near‐natural wetlands, we found a lower species richness and community uniqueness in restored wetlands, but we also found that grazing had a positive effect on vascular plant richness in restored wetlands. The size of the local species pool, presence of near‐natural habitat prior to restoration and near‐natural restored hydrology all had positive effects on plant diversity, whereas high soil iron and nitrogen had negative effects. Synthesis and applications: Restoration of plant diversity in wetlands is challenging, but our results point to potential remedies: plan restoration areas near colonisation sources of the target biota, restore hydrology to near‐natural conditions, discontinue nutrient loads from surrounding arable land and restore near‐natural grazing regimes. Bryophytes may be particularly useful as indicators for successful restoration of wetlands.

Climate change vulnerability of Arctic char across Scandinavia.

Climate change is anticipated to cause species to shift their ranges upward and poleward, yet space for tracking suitable habitat conditions may be limited for range-restricted species at the highest elevations and latitudes of the globe. Consequently, range-restricted species inhabiting Arctic freshwater ecosystems, where global warming is most pronounced, face the challenge of coping with changing abiotic and biotic conditions or risk extinction. Here, we use an extensive fish community and environmental dataset for 1762 lakes sampled across Scandinavia (mid-1990s) to evaluate the climate vulnerability of Arctic char (Salvelinus alpinus), the world's most cold-adapted and northernly distributed freshwater fish. Machine learning models show that abiotic and biotic factors strongly predict the occurrence of Arctic char across the region with an overall accuracy of 89 percent. Arctic char is less likely to occur in lakes with warm summer temperatures, high dissolved organic carbon levels (i.e., browning), and presence of northern pike (Esox lucius). Importantly, climate warming impacts are moderated by habitat (i.e., lake area) and amplified by the presence of competitors and/or predators (i.e., northern pike). Climate warming projections under the RCP8.5 emission scenario indicate that 81% of extant populations are at high risk of extirpation by 2080. Highly vulnerable populations occur across their range, particularly near the southern range limit and at lower elevations, with potential refugia found in some mountainous and coastal regions. Our findings highlight that range shifts may give way to range contractions for this cold-water specialist, indicating the need for pro-active conservation and mitigation efforts to avoid the loss of Arctic freshwater biodiversity.

Characteristics of swiftlet houses on the plains and hills and their contribution to regional development for export development. Case study: Banten Province, Indonesia

Swiftlet bird nests (SBN) have a high selling value for export because they are beneficial for health treatment and are a food ingredient. The sustainability of SBN exports is influenced by the quality of SBN production in swiftlet houses. Banten Province is a producer and supplier of SBN for export and local markets because the SBN produced here is good quality. This study aims to analyze 1) the characteristics of swiftlet houses on plains and hills and 2) the contribution of swiftlet houses to regional development. This study uses a qualitative method with a comparative case study approach. The results showed that 1) There were differences in the characteristics of swiftlet houses located on the plains and hills, namely the geographic location, agro climate, swiftlet house design, food vegetation, and SBN quality; 2) Swiftlet houses contribute to regional development as an opportunity for business and employment in managing swiftlet houses and SBN, as well as SBN quarantine monitoring for export. SBN production is higher in swiftlet houses with suitable habitat and environmental conditions. To increase the sustainability of SBN production, the government and business actors collaborate to preserve the environment and maintain the sustainability of swiftlet houses.

Odonata Assemblages in Urban Semi-Natural Wetlands.

As the human population in urban areas is continuously growing, urbanization is one of the greatest threats to biodiversity. To mitigate the negative effects, the inclusion of blue zones (aquatic habitats) in modern urban development practices is strongly recommended, as they could be beneficial for the local biodiversity conservation. Odonata are a flagship group and are widely used in freshwater conservation as ecological indicators of habitat integrity and health. However, our understanding of their ecological requirements in urban landscapes is not yet complete. Therefore, we analyzed the taxonomic and functional diversity of Odonata in a semi-natural wetland in the Croatian capital. This study was conducted in the summers of 2020 and 2023. Most taxonomic and functional assemblage metrics were comparable between the two main habitat types, anthropogenically disturbed and natural oxbow lakes. However, significant differences were found in relation to the time scale, where most metrics were lower in 2023, indicating the negative impact of extreme climate events (including droughts) that occurred in this region after 2020. With 19 species recorded, our results indicate that semi-natural urban wetlands, especially natural oxbow lakes, have great potential to function as good habitats for Odonata, where even some species of conservation concern were detected. When developing landscape management plans in urban areas, it is essential to consider the importance of habitat heterogeneity in terms of good structure of aquatic macrophytes (presence of submerged, emergent and floating vegetation), which would ensure the most suitable habitat conditions for local Odonata species.

Temporal variation in the relative abundance, suitable habitat selection, and distribution of Ataeniobius toweri (Meek, 1904) (Goodeidae), by life stages, in the Media Luna spring, Mexico

The Media Luna spring, Mexico, is the main reservoir of the endemic and endangered fish Ataeniobius toweri. In the last decades, the ecosystem has been modified by tourism, and the habitat has changed for this species. Therefore, for better conservation management of the natural fish population, it is necessary to understand its abundance status and suitable habitat conditions, in ecological and spatial scenarios, on a temporal scale. In the present study, we modeled A. toweri’s ecological responses and spatial distribution for adult and juvenile life stages, in three summer periods (years 1999, 2009, and 2019). As habitat variables, we used water depth and underwater coverage. Ecological response curves were obtained from a Generalized Linear Model; distribution models were obtained with DOMAIN. In the modeling evaluation, for the Linear Regression Model, we obtained true statistical skills metric > 0.30 and, for DOMAIN, an area under the curve (AUC) > 0.70 with an AUC ratio > 1.00. In general, as the summer periods progressed, we found the highest probability of occurrence (P > 0.20) and distribution (P > 0.60) in areas with conditions of large coverage of underwater vegetation, in the first 1.5 m of depth, and near the shores of the spring. Also, the variations of relative abundance were always observed at sites with these habitat conditions. Thus, we concluded that our models had the performance to discern between suitable and unsuitable habitat conditions for A. toweri, and that areas with little or no anthropogenic pressure are more important for this species.

Cisco population characteristics in Wisconsin lakes in relation to lake‐ and landscape‐level factors

AbstractObjectiveDeclines in Cisco Coregonus artedi populations in some inland lakes have prompted assessments of Cisco occurrence and extirpation risk in relation to various stressors to identify refuge lakes and factors that promote Cisco persistence. However, most previous assessments have focused on presence–absence of Cisco rather than examining how population characteristics, such as relative abundance or growth, might change in relation to lake‐ and landscape‐level environmental factors. Consequently, our specific objectives were to identify important environmental factors explaining variation in Cisco relative abundance and growth and to determine whether population metrics describing size and age distributions were related to relative abundance in Wisconsin inland lakes.MethodsCisco were collected from 48 inland Wisconsin lakes during 2011–2015 using vertical monofilament gill nets and population‐specific relative abundance estimates (catch per unit effort [CPUE]) were quantified as the number of individuals per gill‐net night. Sagittal otoliths were removed from a subsample of Cisco for age estimation and growth was indexed as mean total length (TL; mm) at age 2. Length and age data were used to develop a suite of metrics describing size and age distributions of each population. Random forest models were used to evaluate relationships between 10 biologically relevant predictor variables representing variation in physical, climatic, catchment, and limnological characteristics and Cisco CPUE and growth. Pearson correlations were used to determine whether population characteristics were related to CPUE.ResultCisco populations exhibited large variation in relative abundance, growth, and size and age distributions. Best‐fit random forest models explained approximately 25% of the variation in Cisco CPUE and 46% of the variation in growth. Growing degree‐days and variables associated with availability, quality, and quantity of suitable oxythermal conditions were identified as important predictors of both Cisco CPUE and growth; CPUE was also identified as an important predictor of growth. Mean TL and mean TL at age 2 were negatively related to Cisco CPUE, whereas mean age, number of age‐classes present, and maximum observed age were positively related to CPUE.ConclusionOur results suggest that maintenance of suitable oxythermal habitat conditions may be critical to conserving abundant Cisco populations. Our assessment also provides insights on how Cisco populations may respond to environmental and anthropogenic stressors, which could aid ongoing and future conservation and management efforts in Wisconsin and elsewhere.

Stable carbon, nitrogen, and sulfur isotope composition of Oligobrachia haakonmosbiensis Smirnov, 2000 (Annelida: Siboglinidae) from the shallow-water Laptev Sea shelf

Cold methane seeps create suitable habitat conditions for chemosymbiotic frenulate tubeworms, one of the groups of the family Siboglinidae Caullery, 1914 that can form extensive aggregations at seeps at the shelf of the Arctic seas. The present study provides the first data on the ratio of natural stable C, N, and S isotopes in tissues of the siboglinid tubeworm Oligobrachia haakonmosbiensis found in methane seep fields on the Laptev Sea shelf. Values of δ13C, δ15N, and δ34S for various body parts, such as cephalic and abdominal regions, tissues, whole worms with their tubes, and also worms and tubes separated, fixed in 96% ethanol, have been obtained for O. haakonmosbiensis. The lowest isotopic composition values were recorded from bodies of O. haakonmosbiensis with their tubes collected in the coastal zone at a depth of 25m (δ13C = –72.7±1.9‰; δ15N = –10.9±1.2‰; and δ34S = –28.1±1.9‰). Such low values are suggested to be associated mainly with large amounts of dissolved organic matter near the Lena River estuary. Our analysis of stable C, N, and S isotopes of O. haakonmosbiensis from the Laptev Sea has shown that the major energy source for symbiotic bacteria of this tubeworm species is hydrogen sulfide.

From separation to incorporation: Development of a unifying framework that integrated bird habitats with public recreation spaces within the wetland park system

The Ramsar Convention places central emphasis on the protection, restoration, and utilization of wetlands. Wetland species and their habitat protection is an important embodiment of wetland system protection. Simultaneously, the importance of recreation as a form of human activity within wetlands should not be underestimated. Wetland parks, as a mode of rational wetland use, provide the public opportunities for leisure and entertainment, exemplifying China's commitment to the Ramsar Convention on Wetlands. However, With the acceleration of urbanization, the degree of fragmentation of the wetland system is increasing. The wetland park and its surrounding landscape elements are separated from each other, resulting in the phenomenon of islanding, which is not conducive to the protection and utilization of wetland biodiversity. This study focuses on Yancheng coastal wetland, a UNESCO World Heritage site in Jiangsu, China, as its research area. It integrates habitat birds, a core component of wetland biodiversity, into the development framework of wetland parks. The study proposes the use of composite habitat corridors to connect fragmented bird habitats with public recreational areas, establishing a collaborative wetland park system. The methodology involved three key steps: (1)Spatial Modeling. Utilizing Maxent, the spatial distribution of birds and public recreation areas was modeled, and suitable patches for both were extracted. (2) Corridor Identification. Linkage Mapper was employed to identify bird and recreational corridors, while the MCR model was used to pinpoint composite habitat corridors. (3) Network Development. Corridors generated in the previous step were superimposed on the ArcGIS platform to create a network of interconnected bird habitats and public recreation areas within the wetland park system. The study's results demonstrate: (1) There are obvious spatial distribution differences between the current core bird habitat and public recreation areas in Yancheng coastal wetland. (2) The establishment of a composite corridor network realizes the interconnection between bird habitats and public recreation areas，among them, the corridor network in the southern region is short and dense, with higher stability. (3) The areas passed by the composite corridor network are mainly productive landscapes such as cultivated land and aquaculture ponds, and therefore, certain protection and restoration measures should be taken to create suitable habitat conditions for birds and humans. This study provides a novel model for wetland protection and sustainable utilization, particularly relevant to many developing countries facing similar challenges.

Analysis of the Potential Range of Mountain Pine-Broadleaf Ecotone Forests and Its Changes under Moderate and Strong Climate Change in the 21st Century.

Climatic changes have a significant impact on the composition and distribution of forests, especially on ecotone ones. In the Southern Ural, pine-broadleaf ecotone forests were widespread during the early Holocene time, but now have persisted as relic plant communities. This study aimed to analyze the current potential range and to model changes in habitat suitability of relic pine-broadleaf ecotone forests of the suballiance Tilio-Pinenion under scenarios of moderate (RCP4.5) and strong (RCP8.5) climate change. For modelling, we used MaxEnt software with the predictors being climate variables from CHELSA Bioclim, the global digital soil mapping system SoilGrids and the digital elevation model. In the Southern and Middle Urals, climate change is expected to increase the areas with suitable habitat conditions of these forests by the middle of the 21st century and decrease them in the second half of the century. By the middle of the 21st century, the eastern range boundary of these forests will shift eastward due to the penetration of broad-leaved tree species into coniferous forests of the Southern Ural. In the second half of the century, on the contrary, it is expected that climate aridization will again shift the potential range border of these forests to the west due to their gradual replacement by hemiboreal coniferous forests. The relationship between the floristic composition of pine-broadleaf forests and habitat suitability was identified. In low and medium habitat suitability, pine-broadleaf forests contain more nemoral species characteristic of deciduous forests of the temperate zone, and can be replaced by broadleaf forests after thinning and removal of pine. In the Volga Upland, suitable habitats are occupied by pine-broadleaf forests of the vicariant suballiance Querco robori-Tilienion cordatae. Projected climatic changes will have a significant impact on these ecotone forests, which remained completely unaltered for a long time.

Geography, climate and shifts in host plants distribution explain the genomic variation in the cactus moth

Landscape heterogeneity and the host plant use are factors suggested to play determinant roles in shaping the evolutionary history of herbivorous insects. However, the role of the reconfiguration of host plants distributions linked to Quaternary climate oscillations as drivers of contemporary population genetic structure is still poorly understood. Here, we formally examine the relative contribution of such factors on intraspecific diversification using the South American cactus moth, Cactoblastis cactorum, an herbivore insect specialized in the use of cacti as host plants. We assessed genomic variation using genome-wide SNPs and mitochondrial data in populations sampled across a broad geographical gradient where moths feed on different cactus species. We integrated demographic simulations and ecological niche modeling into a landscape genomics framework, to test alternative hypotheses of past and current population connectivity for both C. cactorum and its host plants. Regions exhibiting higher genomic diversity were evaluated for congruence with areas where suitable climatic conditions remained stable through time. Our results revealed that past spatial configuration of suitable habitat conditions and shifts of host plants distributions are the factors that better explain the intraspecific diversification. Genomic data also supported the hypothesis that areas of long-term habitat stability served as refugia for C. cactorum, enabling the maintenance of high levels of genetic diversity over time. Overall, our study highlights the importance of integrating inter-specific interactions and their spatio-temporal dynamics to better understand the relative importance of abiotic and biotic factors driving the diversification processes in herbivorous insects with broad geographical and restricted host ranges.

Neutral genetic diversity follows a latitudinal gradient in the endangered plant Arnica montana L.: a range-wide study

Arnica montana is a clonal, self-incompatible herb of economic and intrinsic ecological value which is declining in large parts of its range. With the employment of microsatellite markers, we characterized the population structure and distribution of genetic diversity of 40 populations of A. montana sampled throughout Europe. We detected a clear geographical pattern of isolation and strong population structure, indicating limited gene flow. We also observed a negative latitudinal gradient in genetic diversity. Such patterns can be explained by paleo-historical colonization routes following the last glacial maximum, with regions characterized by higher genetic diversity corresponding to former glacial refugia. We recommend the implementation of conservation measures such as assisted gene flow in the populations characterized by low genetic diversity under consideration of the observed population structure. For the populations where high levels of genetic diversity are still retained, we recommend the maintenance of suitable habitat conditions. Our study emphasises the importance of conducting large-scale population genetic studies that consider postglacial recolonization history when planning active conservation measures such as assisted gene flow.

Isolation by resistance explains genetic diversity in the Arremon brushfinches of northern Mesoamerica.

Genetic differentiation between and within natural populations is the result of the joint effects of neutral and adaptative processes. In addition, the spatial arrangement of the landscape promotes connectivity or creates barriers to gene flow, directly affecting speciation processes. In this study, we carried out a landscape genomics analysis using NextRAD data from a montane forest specialist bird complex, the Mesoamerican Chestnut-capped/Green-striped Brushfinch of the genus Arremon. Specifically, we examined population genomic structure using different assignment methods and genomic differentiation and diversity, and we tested alternative genetic isolation hypotheses at the individual level (e.g., isolation by barrier, IBB; isolation by environment, IBE; isolation by resistance, IBR). We found well-delimited genomic structuring (K = 5) across Mesoamerican montane forests in the studied group. Individual-level genetic distances among major montane ranges were mainly explained by IBR hypotheses in this sedentary Neotropical taxon. Our results uncover genetic distances/differentiation and patterns of gene flow in allopatric species that support the role of tropical mountains as spatial landscape drivers of biodiversity. IBR clearly supports a pattern of conserved niche-tracking of suitable habitat conditions and topographic complexity throughout glacial-interglacial dynamics.

Influence of fine-scale habitat characteristics on sage-grouse nest site selection and nest survival varies by mesic and xeric site conditions

AbstractResource managers and scientists across western U.S. agencies seek methodologies for identifying environmental attributes important to both wildlife conservation and broad-scale land stewardship. The Greater Sage-Grouse (Centrocercus urophasianus; hereafter, sage-grouse) exemplifies a species in need of this broad-scale approach given widespread population declines that have resulted from loss and degradation of habitat from natural and anthropogenic disturbances. These include agricultural land conversion, conifer expansion, energy development, and wildfire coupled with ecological conversion by invasive plants such as cheatgrass (Bromus tectorum). Development of habitat assessments and conservation actions for sage-grouse benefit from studies that link demographic responses to habitat selection patterns. To address this, we examined nest survival of sage-grouse in relation to fine-scale habitat patterns (i.e., field-based habitat measurements) that influenced nest site selection, using data from nests of telemetered females at 17 sites over 6 years in Nevada and northeastern California, USA. Importantly, sites spanned mesic and xeric average precipitation conditions that contributed substantially to vegetation community structure across cold desert ecosystems of the North American Great Basin. Vegetative cover immediately surrounding sage-grouse nests was important for both nest site selection and nest survival, but responses varied between mesic and xeric sites. For example, while taller perennial grasses were selected at xeric sites, we found no evidence of selection for perennial grass at mesic sites, indicating a functional response to availability of habitat features between hydrographic regions. Furthermore, perennial grass height and forb height both had positive effects on nest survival at xeric sites, but we found varying effects at mesic sites. We emphasize that precipitation conditions driving ecosystem productivity vary regionally among sagebrush communities, shaping vegetation structure and suitable habitat conditions for nesting sage-grouse.

An Assessment of Prairie Management Practices for Maintaining Habitat Quality for the Endangered Poweshiek Skipperling Butterfly in Canada

The Poweshiek skipperling (Oarisma poweshiek) was once a common prairie butterfly in central North America, but is now critically endangered in Canada and the United States. The Poweshiek skipperling is confined to the largest remaining tall grass prairie in Canada, which is currently managed using grazing and fire to maintain prairie habitat and prevent forest and shrub encroachment. To support re-introduction, restocking, and recovery of this critically endangered species, it is necessary to understand the habitat conditions preferred by skipperlings. By surveying prairie sites with Poweshiek skipperling across age and treatment categories (1–2 y since burn, 4–6 y since burn, >15 y since burn, and grazing), we identified commonly-used nectar plants and recorded physical variables known to influence plant diversity. We measured soil variables, including macronutrients, compaction, pH, texture, and moisture content, and used multivariate statistics to test for significant differences in site characteristics and plant community across treatments. For each site, we captured plant diversity, abundance, and cover, as well as total plant biomass. We found the oldest burn sites had the fewest skipperlings. Intermediate burn sites and lightly grazed sites contained the most skipperlings. In 95% of nectaring observations, adult skipperlings were feeding on Black-eyed Susan (Rudbeckia hirta), upland white aster (Solidago ptarmicoides), and Self-heal (Prunella vulgaris). Characteristics in the physical components of sites and plant communities did not significantly differ across treatment types for most variables with the exception of the oldest burns, which showed significantly higher levels of soil compaction, live biomass, bare ground, less flowering species during the flight period, less flowering stems, and increased presence of nonnative and invasive species. Poweshiek skipperling is at high risk of imminent extirpation, and we recommend that the management regimes be adjusted to plan for a consistent supply of habitat conditions and plant species composition exemplified by our intermediate burn sites. We suggest fire return intervals of 4–6 y using patch burns in combination with grazing, permitted at times that minimize the impact on immature stages of Poweshiek skipperling. This management is needed to provide suitable habitat conditions to maintain the current population and allow for successful restocking and recovery.

Past, present, and future predictions on the suitable habitat of the Slender racer (Orientocoluber spinalis) using species distribution models.

Species distribution models (SDMs) across past, present, and future timelines provide insights into the current distribution of these species and their reaction to climate change. Specifically, if a species is threatened or not well‐known, the information may be critical to understand that species. In this study, we computed SDMs for Orientocoluber spinalis, a monotypic snake genus found in central and northeast Asia, across the past (last interglacial, last glacial maximum, and mid‐Holocene), present, and future (2070s). The goal of the study was to understand the shifts in distribution across time, and the climatic factors primarily affecting the distribution of the species. We found the suitable habitat of O. spinalis to be persistently located in cold‐dry winter and hot summer climatic areas where annual mean temperature, isothermality, and annual mean precipitation were important for suitable habitat conditions. Since the last glacial maximum, the suitable habitat of the species has consistently shifted northward. Despite the increase in suitable habitat, the rapid alterations in weather regimes because of climate change in the near future are likely to greatly threaten the southern populations of O. spinalis, especially in South Korea and China. To cope with such potential future threats, understanding the ecological requirements of the species and developing conservation plans are urgently needed.

Response of Soil Fauna to the Shift in a Riparian Landscape along an Urban-Rural Habitat Gradient.

Urbanization is accelerating worldwide, resulting in drastic alterations of natural riverbanks, which seriously affects the ecological functions and services of riparian landscapes. Our understanding of how anthropogenic activities influence soil animal communities within riparian zones is scarce. The soil fauna represents an important biotic component of the soil ecosystem and greatly contributes to soil structure and fertility formation. We investigated the richness, abundance, diversity, and distribution of soil animal groups, including macro- and mesofauna, in different riparian landscapes along an urban–rural habitat gradient. In natural riparian zones with permeable revetments, the soil fauna was richest and most abundant, mainly because of the low levels of human disturbance and the more suitable habitat conditions. Different soil animal groups responded differently to revetment type and distance from the water flow. The hygrophilous soil mesofauna, requiring a more humid environment, was more sensitive to shifts in revetment types, the location on the riverbank, and the seasons. In summer, when precipitation in the study area was highest, the abundance of the hygrophilous soil mesofauna was significantly higher than in autumn. Distance from the water flow significantly affected the abundance of the hygrophilous soil mesofauna. Our results demonstrated that hygrophilous soil mesofauna can serve as a good indicator in riparian zones, reflecting the hydrological conditions. We also observed interactions between revetment type and distance from the water flow; the distance effect was stronger in the natural riparian zone with a permeable revetment type. Our results highlight the importance of anthropogenic effects on soil ecosystem processes and functions in riparian landscapes, and the necessity of protecting and retaining the natural riverbank and native vegetation patches in riparian landscape planning and construction.

Varying Responses of Invertebrates to Biodynamic, Organic and Conventional Viticulture

Alternative farming methods must be deployed to mitigate the detrimental impacts of intensive agriculture on climate, biodiversity, and ecosystem services. Organic and biodynamic farming are environmental-friendly practices that progressively replace conventional agriculture. While potential biodiversity benefits of organicvs. conventional farming have been studied repeatedly, the effects of biodynamic farming on biodiversity remain ill-understood. We investigated the effects of these three main management regimes, and their interaction with ground vegetation cover, on vineyard invertebrate communities in SW Switzerland. Invertebrates were sampled three times during the vegetation season in 2016, focusing on ground-dwelling (pitfall traps) and epiphytic (sweep-netting) invertebrates, and their abundance was modelled for single, additive, and interactive influences of management and ground vegetation cover. Overall, organic and, but to a lesser degree, biodynamic vineyards provided better conditions for invertebrate abundance than conventional vineyards. On the one hand, there was a significant interaction between management and ground vegetation cover for epiphytic invertebrates with a positive linear increase in abundance in organic, a positive curvilinear relationship in biodynamic but a negative curvilinear response to vegetation cover in conventional vineyards. The abundance of ground-dwelling invertebrates was primarily affected by the management regime alone, i.e. without any interaction with ground vegetation characteristics, leading to much higher abundances in organic compared to conventional vineyards, while biodynamic did not differ from the other two regimes. We interpret the patterns as follows: organic grape production offers more suitable habitat conditions for invertebrates due to a spatially more heterogenous but also less often disturbed (compared to biodynamic management) or destroyed (compared to conventional) ground vegetation cover, in line with the predictions of the intermediate disturbance hypothesis. Biodynamic and conventional viticultural management regimes often provide a habitat that is either too mineral (conventional: ground vegetation widely eliminated) or subject to soil disturbance happening frequently through ploughing (biodynamic). We conclude that alternative farming methods do promote biodiversity in vineyard agro-ecosystems, especially so organic management.

Study on the Forming Mechanism of the High-Density Spot of Locust Coupled with Habitat Dynamic Changes and Meteorological Conditions Based on Time-Series Remote Sensing Images

The outbreak of the Asian migratory locust (Locusta migratoria migratoria) (AML) can deal a great blow to agriculture and grassland farming. The emergence of high-density locusts facilitates the outbreak of locusts. Understanding the forming mechanism of the high-density spot of locust (HDSL) is very important for locust monitoring and control. To achieve this goal, this paper took Nong’an County, which used to form an HDSL in 2017, as the study area. Firstly, based on the habitat classification system, support vector machine (SVM), random forest (RF), and maximum likelihood (ML) methods were employed to explore the best classification method for locust habitats. Then, the optimal method was applied to monitor habitat dynamic changes from 2014 to 2017 in the HDSL in Nong’an. Finally, the HDSL forming mechanism was clarified coupled with habitat dynamic changes and meteorological data. The results showed that the SVM method was the optimal method, with an accuracy of 95.28%, which is higher than the RF and ML methods by 0.25% and 8.52%, respectively. The annual increased barren land and sufficient reeds provided adequate suitable habitats for the breeding of AML. From 2014 to 2016, the temperatures during the overwintering and hatching periods were higher than the 2010–2018 average, and the precipitation during the spawning period was lower than the 2010–2018 average. The precipitation during the growing period in 2017 was 30.8 mm less than the average from 2010 to 2018. All these characteristics were conducive to the reproduction of locusts. We concluded that the suitable habitat and meteorological conditions increased the locust quantity yearly, resulting in the formation of HDSL. These results are instrumental for monitoring potential high-risk outbreak areas, which is important to improve locust control and ensure food security.

HABs in coastal upwelling systems: Insights from an exceptional red tide of the toxigenic dinoflagellate Alexandrium minutum

Alexandrium minutum blooms generally occur in semi-enclosed sites such as estuaries, harbours and lagoons, where enhanced stratification, restricted circulation and accumulation of resting cysts in the sediment set suitable habitat conditions for the proliferation of this paralytic shellfish poisoning toxigenic species. In the Galician Rías Baixas (NW Iberian Peninsula), according to weekly time-series between 1994 and 2020, blooms of A. minutum were recurrent in small, shallow estuarine bays inside the Rías de Vigo and Pontevedra, but rarely detected, and if so at low concentrations, out of these environments. However, from May to July 2018 it developed as usual in the small inner bays but then spread over both Rías (Vigo and Pontevedra) causing discoloured waters during one month and prolonged harvesting closures. Meteorological conditions during that period (rains / runoff higher than climatological averages, sustained temperature increment and oscillating wind pattern –i.e., series of upwelling-relaxation cycles), fostered optimal circumstances for the development of that extensive and massive proliferation: strong vertical stratification and the alternation of retention and dispersion processes. Simulations from a particle tracking model portrayed the observed bloom development phases: onset and development inside a small inner bay; transport within the surface layer, from these sites towards the interior parts of the Ría; and dispersion all over the embayment. Seedbeds with high concentrations of resting cysts were detected several months after the bloom, which may have favoured flourishment of A. minutum in the following two years, markedly in 2020. The present work contributes to the general understanding of the dynamics of harmful algal blooms (HABs), from which surveillance indicators of the state of marine ecosystems and their evolution can be derived. We hypothesize that the intensity and frequency of A. minutum proliferations in the Galician Rías could increase under projected climate trends.

Coupling fossil records and traditional discrimination metrics to test how genetic information improves species distribution models of the European beech Fagus sylvatica

Species distribution models (SDMs) are widely used to hindcast or forecast suitable habitat conditions during climate change. Although distant populations of a given species may show local adaptations to diverging environmental conditions, traditional SDMs disregard intraspecific variation. Yet, incorporating genetic information into SDMs could improve predictions. Here we aimed at investigating whether genetically informed SDMs would outperform traditional SDMs. Using published information on the spatial genetic structure of the European Beech Fagus sylvatica L. (1753), we built lineage-specific SDMs for each phylogenetic group of the species. We then combined all lineage-specific SDMs into a single genetically informed SDM that we compared against a traditional SDM approach. We finally compared SDMs’ predictions against independent datasets of present-day distribution as well as fossil distribution data from the Mid-Holocene, using six metrics of model performance. We found that aggregating lineage-specific SDMs into a single genetically informed SDM increased model performances to identify suitable areas currently occupied by F. sylvatica. In comparison to a traditional SDM, the genetically informed SDM we built for F. sylvatica assigned higher probabilities of occurrence during the Mid-Holocene at locations where fossil records were found. Aggregating lineage-specific SDMs into a single genetically informed SDM seems to outperform the traditional SDM approach, especially so when the aim is to identify potentially suitable areas of occupancy. This could be particularly useful for the identification of cryptic refugia that remain undetected by traditional SDMs. Genetically informed SDMs have the potential to improve our understanding of species redistribution under climate change.