Undisturbed Areas Research Articles

Human–wildlife interactions on the tidal flats of the Bijagós Archipelago: does shellfishing affect migratory shorebirds?

The Bijagós Archipelago in West Africa is home to an ethnic group with a rich cultural heritage that is tightly linked to nature. The Bijagós people have a shared cultural identity, but management of natural resources varies between islands due to island‐specific context with regards to socio‐political organization and strength of cultural heritage. Across the archipelago, bivalves harvested manually from the mudflats are an important part of the Bijagós people's diet, economy, and culture. Migratory shorebirds share the use of these mudflats during their non‐breeding season, consuming macrobenthos such as crustaceans and bivalves, including those harvested by local people. At the end of their stay in the Bijagós, just before taking off for their migratory flight, it is particularly important that shorebirds have access to undisturbed feeding areas with suitable food resources. In this study we start by exploring shellfishing patterns across different management regimes (via questionnaires to local shellfishers), then assess seasonal variation in the direct impact of shellfishing on shorebirds (through competition for resources and space), and finally quantify the indirect impact of sediment disturbance due to shellfishing upon shorebird prey availability with an experimental approach. Results indicate that bivalve resources are better managed in areas with formal protection, while traditional management based on cultural beliefs results in poorer stock conditions. Interestingly, the high density of shellfishers in mid‐winter (14.4 ind. km−2) decreased markedly towards shorebirds' fuelling period, when they benefit the most from reduced disturbance on the mudflats. Regardless of the season, no direct competition for resources was detected due to differences in targeted sizes. Indirect impacts caused by sediment disturbance during shellfishing were also mostly absent, causing only a small reduction on shorebirds prey density but with no effect on the available biomass.

Effects of aerial liming on soil chemical and biological properties in metal contaminated and inaccessible lands in Ontario (Canada).

The manual addition of lime to soil, in addition to tree planting and fertilization have been the dominant strategy described in restoration protocols for ecosystems damaged by acid rain and metal contamination. Investigations on aerial-limed soils in inaccessible lands are limited. The objective of this study was to assess the effects of aerial liming on soil pH, organic matter, microbial biomass, and enzymatic activities, and aboveground plant population quality in metal-contaminated lands in northern Ontario, Canada. Soil samples were collected from three sites around the City of Greater Sudbury with each pair being composed of a reclaimed (areal-limed) site and an adjacent undisturbed (unlimed) area. Soil physico-chemistry, microbial biomass (assessed by Phospholipid fatty acid analysis) and enzymatic activities were analyzed. Soil pH was higher in limed sites compared to unlimed at recently restored sites (Baby Lake and Wahnapitae) but not at the oldest reclaimed site (HWY 80 N). Organic matter was higher in limed areas compared to the unlimed reference site only at most recently reclaimed site at Baby Lake. Aboveground plant population health was visibly improved in limed sites compared to unlimed areas. Metal concentrations of iron (Fe) and arsenic (As), total microbial biomasses, gram-negative bacterial, fungal, and eukaryotic biomasses were all significantly increased in the limed soils compared to the unlimed samples. The same trend was observed for the activities of three of the enzymes tested, β-N-acetylglucosaminidase (BG), aryl sulfatase (AS), and glycine aminopeptidase (GAP). Interestingly, strong positive correlations between the levels of soil organic matter, microbial biomasses, and NAGase and ALP activities were observed. Although expensive, aerial liming is effective in restoring inaccessible sites impacted by smelting operations where other methods cannot easily be used.

Impact of winch-assisted logging machinery on soil disturbance in the mountainous forests of Western Carpathians

IntroductionTimber harvesting on steep terrain is a challenge in terms of economic viability, safety, and environmental performance. Felling with chainsaws and use of yarders seems optimal in this environment. However, using mobile traction winches allows for the safe work of ground-based technologies even in these challenging conditions.MethodsOur study assessed the impact of winch-assisted cut-to-length harvesting on soil disturbance in young forest stands (up to 40 years old) across slopes of 14.9°-27.4° (27–52%). Utilizing 78 measurement points (i.e., 234 measurements), we analyzed soil samples from trail ruts, between ruts, and undisturbed areas for soil bulk density (g.cm−3) and soil moisture content (%), simultaneously measuring penetration resistance (MPa), penetration depth (cm) and rut depth (cm).ResultsThe results highlighted that areas without winch assistance experienced the most significant increases in soil bulk density (up to 22.35%) and penetration resistance (up to 26.8%), though these differences were not statistically significant. Linear mixed effects models did not confirm a significant effect (p > 0.05) of a traction winch on the soil bulk density (g cm−3) and penetration resistance (MPa) in the ruts of the forwarding trails. Mean forwarding trail profile depths ranged from 4.63 to 7.28 cm, with the maximum depths between 10.86 and 17.25 cm, showing deeper ruts in non-assisted areas. Moreover, the presence of the traction winch (p < 0.05) significantly affected the maximal depth of the forwarding trail rut.ConclusionThe findings suggest that winch-assisted harvesting may mitigate soil disturbance (rut depths) on steep slopes, offering a sustainable option for utilizing ground-based machinery with reduced environmental impact.

Diversity of bacterial communities in wetlands of Calakmul Biosphere Reserve: a comparative analysis between conserved and semi-urbanized zones in pre-Mayan Train era

BackgroundThe Calakmul Biosphere Reserve (CBR) is known for its rich animal and plant biodiversity, yet its microbial communities remain largely unknown. The reserve does not possess permanent bodies of water; nevertheless, seasonal depressions associated with fractures create wetlands, known locally as aguadas. Given the recent construction of the Maya train that crosses the CRB, it is essential to assess the biodiversity of its microorganisms and recognize their potential as a valuable source of goods. This evaluation is pivotal in mitigating potential mismanagement of the forest ecosystem. To enhance comprehension of microbial communities, we characterized the microbiota in three different wetlands. Ag-UD1 and Ag-UD2 wetlands are located in a zone without human disturbances, while the third, Ag-SU3, is in a semi-urbanized zone. Sampling was carried out over three years (2017, 2018, and 2019), enabling the monitoring of spatiotemporal variations in bacterial community diversity. The characterization of microbiome composition was conducted using 16S rRNA metabarcoding. Concurrently, the genomic potential of select samples was examined through shotgun metagenomics.ResultsStatistical analysis of alpha and beta diversity indices showed significant differences among the bacterial communities found in undisturbed sites Ag-UD1 and Ag-UD2 compared to Ag-SU3. However, no significant differences were observed among sites belonging to the undisturbed area. Furthermore, a comparative analysis at the zone level reveals substantial divergence among the communities, indicating that the geographic location of the samples significantly influences these patterns. The bacterial communities in the CBR wetlands predominantly consist of genera from phyla Actinobacteria, Acidobacteria, and Proteobacteria.ConclusionThis characterization has identified the composition of microbial communities and provided the initial overview of the metabolic capacities of the microbiomes inhabiting the aguadas across diverse conservation zones. The three sites exhibit distinct microbial compositions, suggesting that variables such as chemical composition, natural and anthropogenic disturbances, vegetation, and fauna may play a pivotal role in determining the microbial structure of the aguadas. This study establishes a foundational baseline for evaluating the impact of climatic factors and human interventions on critical environments such as wetlands.

Potential impacts of refugee camps on wetland herpetofauna in Uganda

Wetlands are one of the world’s fastest shrinking ecosystems, yet they are home to roughly 43% of all reptile and amphibian species. Sub-Saharan Africa has the fastest growing human population on the planet while also experiencing significant internal migrations of displaced peoples who settle in refugee camps. These camps are often in remote and previously undisturbed areas where interactions with wildlife are common. Reptiles and amphibians can be used to assess the health and resilience of habitats as a result of their sensitivity to environmental conditions. We sampled the herpetofauna of five wetlands located around two major refugee camps in Uganda using time-constrained visual encounter surveys during both nighttime and daytime. We provide baseline data on these wetland populations and compared them using alpha and beta diversity indices. These are the first data for refugee camp herpetofaunal communities, allowing for future comparisons of the effects of increased human pressure within these camps as well as the ability to better incorporate education and management to help conserve these wetlands and the species that inhabit them.

Trends in habitat quality and habitat degradation in terrestrial protected areas.

Protected areas are typically considered a cornerstone of conservation programs and play a fundamental role in protecting natural areas and biodiversity. Human-driven land-use and land-cover (LULC) changes lead to habitat loss and biodiversity loss inside protected areas, impairing their effectiveness. However, the global dynamics of habitat quality and habitat degradation in protected areas remain unclear. We used the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model based on global annual remotely sensed data to examine the spatial and temporal trends in habitat quality and degradation in global terrestrial protected areas. Habitat quality represented the ability of habitats to provide suitable conditions for the persistence of individuals and populations, and habitat degradation represented the impacts on habitats from human-driven LULC changes in the surrounding landscape. Based on a linear mixed-effects modeling method, we also explored the relationship between habitat degradation trends and protected area characteristics, biophysical factors, and socioeconomic factors. Habitat quality declined by 0.005 (0.6%) and habitat degradation increased by 0.002 (11%) from 1992 to 2020 globally, and similar trends occurred even in remote or restrictively managed protected areas. Habitat degradation was attributed primarily to nonirrigated cropland (62%) and urbanization (27%) in 2020. Increases in elevation, gross domestic production per capita, and human population density and decreases in agricultural suitability were associated with accelerated habitat degradation. Our results suggest that human-induced LULC changes have expanded from already-exploited areas into relatively undisturbed areas, and that in wealthy countries in particular, degradation is related to rapid urbanization and increasing demand for agricultural products.

Evaluation of changes in soil physical properties 20 years after skidding operations

ABSTRACT Soil degradation can negatively impact its physical and chemical properties over the long term. We investigated the natural recovery of physical properties of disturbed soils on an abandoned machine operating trail in a deciduous mountain forest in northern Iran. The machine operating trail hadn’t been used for the last 20 years. Dry bulk density and total porosity were assessed for three levels of traffic intensity (light, moderate, and heavily trafficked trails) and two levels of slope gradients (gentle, ≤20%, and steep, >20%), in four different soil depths (0–10, 10.1–20, 20.1–30, and 30.1–40 cm) as well as in undisturbed (control) areas. Over the course of the 20-year recovery period, it was observed that in the depth intervals of 0–10, 10.1–20, 20.1–30, and 30.1–40 cm, trails subjected to heavy traffic on gently sloping terrain displayed mean values that exhibited an increase of 78%, 62%, 55%, and 47% in bulk density, respectively, and a decrease of 27%, 26%, 28%, and 27% in total porosity, respectively, when compared to undisturbed soil. In the case of steep slopes, analogous assessments indicated an increase of 82%, 69%, 39%, and 31% in bulk density, respectively, and a reduction of 28%, 29%, 26%, and 24% in total porosity, respectively, within the aforementioned depth intervals. However, in the case of lightly trafficked trails situated on gentle slopes, there was a discernible amelioration in surface soil compaction. Our findings consequently suggest that the natural recovery of soil physical properties in the study area extends beyond the examined timeframe of twenty years.

Disturbance amplifies sensitivity of dryland productivity to precipitation variability.

Variability of the terrestrial global carbon sink is largely determined by the response of dryland productivity to annual precipitation. Despite extensive disturbance in drylands, how disturbance alters productivity-precipitation relationships remains poorly understood. Using remote-sensing to pair more than 5600 km of natural gas pipeline corridors with neighboring undisturbed areas in North American drylands, we found that disturbance reduced average annual production 6 to 29% and caused up to a fivefold increase in the sensitivity of net primary productivity (NPP) to interannual variation in precipitation. Disturbance impacts were larger and longer-lasting at locations with higher precipitation (>450 mm mean annual precipitation). Disturbance effects on NPP dynamics were mostly explained by shifts from woody to herbaceous vegetation. Severe disturbance will amplify effects of increasing precipitation variability on NPP in drylands.

Post-mined reclamation condition assessment by Normalized Difference Vegetation Index (NDVI)

Post-mined reclamation is an essential phase in coal mining operations, ensuring that the ex-mining area can function again according to its intended purpose in the future. This study aimed to elucidate the differences in planting years of post-mined reclamation at a coal mine in the Paringin area, South Kalimantan, Indonesia, and compared them to undisturbed areas for the years 2003 and 2023. NDVI was used for land cover analysis based on the Ministry of Energy and Mineral Resource Regulation, and the ultimate criterion for 100% success in post-mined reclamation is vegetation canopy coverage. The NDVI results showed an improvement in NDVI values for the post-mined reclamation area from 2003 to 2023, indicating an improvement in land cover due to the revegetation process. In 2023, the NDVI results of the post-mined reclamation for eight and twenty years of tree planting showed NDVI values of 0.6-0.7 (moderate vegetation). However, the results of field observations of the twenty-year post-mined reclamation tree condition indicate the non-survival of fast-growing tree species, such as Albizia chinensis. The composition of fast-growing and local tree species, with a minimum proportion of 60:40, and systematic tree distribution across the post-mined reclamation area are required to maintain canopy coverage of the post-mined reclamation area in the long term. Fast-growing tree species, as pioneers, have short to medium life periods. Therefore, the ultimate criterion for 100% success in post-mined reclamation for canopy coverage should be based on local tree species, serving as the basis for releasing the reclamation bond.

IMPROVEMENT OF ELEMENTARY COMPONENT OF DAMAGED SUBSTRATES BY SAPONITE CLAY INCLUSION

In this proposed article, the impact on the elemental composition of sand substrates is determined using the example of the Andriykovetskyi quarry-dump complex and the Barsukivskyi sand pit, which are located in the Central Podillya region in the conditions of the Right-Bank Forest-Steppe. It was determined, that saponite clay contains a significant amount of macro- and micro- elements, and the directions of this use depend on the composition and origin of saponite: in agriculture, in industry, in construction, an application as a sorbent or as meliorant, etc. It is noted that the use of saponite as an ameliorant is an economical and cost-effective method of reclamation, which allows to reduce the burden on the environment caused by the extraction of minerals, pollution of the territory by heavy metals, the conduct of hostilities, etc. General scientific (analysis), statistical (statistical analysis) and laboratory methods (Fourier-transform spectroscopy) were used to assess the qualitative composition of inorganic and organic components of sand-saponite mixtures and to determine saponite clay as a potentially fertile material. To conduct the research, an averaged sample of sand was taken from the Andriykovetskyi quarry and dump complex and from the Barsukivskyi sand pit. For comparison with reference values, a zonal soil sample was taken from undisturbed areas. Saponite from the Tashkiv deposit with a fraction of 0.1 mm was used for sand-saponite mixtures, the ratio of sand substrate to saponite is 70% to 30%. According to the results of the study of the qualitative composition of the inorganic component, it was determined, that saponite has a positive effect on the composition of the sand-saponite mixture in terms of providing plants with nutrients, such as macro- and micro- elements (Mg, K, Na, Cu, Zn, Ca). This confirms the positive effect of saponite on plant growth, which was obtained by us in previous biotesting experiments, and is explained by the fact that the elements of the sand-saponite substrate are available to plants as a result of their transition into the substrate solution. Adding saponite to the substrate of sand pits also increases the content of organic substances, which accelerates the processes of humification and the formation of soil aggregates: humic acid contributes to the bonding of soil particles; carbohydrates sucrose, fructose, glucose and lactose create a nutrient environment for plants; stearates and stearic acid are the main soap components, lauric acid is a foaming catalyst, their presence in sand-saponite mixtures indicates their transition from saponite. When comparing the samples of sand-saponite mixtures of the Andriykovetskyi quarry-dump complex and the Barsukivskyi sand pit, it was concluded that the processes of soil formation began in the substrate of the Andriykovetskyi quarry-dump complex, since the composition of organic matter is greater here.

Effect of Hydrocarbon Pollution on the Fungal Communities of the White and Barents Sea Littoral Sediments

The effect of hydrocarbon pollution on the fungal communities of littoral sediments of the cold-water White and Barents seas was investigated. The samples were collected at locations with different levels of pollution with oil products, from ports to relatively undisturbed areas. Using the diesel fuel-containing medium resulted in detection of hydrocarbon-degrading fungi in almost all studied samples, although in all cases they were less diverse than sugar-degrading fungi. In this relatively small group, Penicillium chrysogenum and Penicillium brevicompactum were the most common organisms. Fungal communities isolated on a sugar-containing medium exhibited higher diversity and abundance, with being the most common sugar degraders. The major factors affecting the structure of the fungal communities were the percentage of hydrocarbons in the total mass of organic carbon in the samples in the case of hydrocarbon-degrading fungi and location, for sugar degraders. In the experiment, the highest hydrocarbon-degrading activity was shown for Penicillium chrysogenum (the loss of residual hydrocarbons was 77.4%), Cadophora fastigiata (72%), and Tolypocladium inflatum (67.2%).

Relationship Between Fine Root Biomass and Soil Physico-chemical Properties of Grassland Ecosystem in Bhadrapur Municipality of Jhapa district, Eastern Nepal

This study investigated the distribution of fine root biomass and various soil properties in a grassland ecosystem within Bhadrapur Municipality, Nepal. Soil samples were systematically collected from randomly selected blocks in undisturbed, disturbed, and roadside areas during the late rainy season. Analyses included soil texture, moisture content, temperature, pH, and quantification of fine root biomass (FRB; <5 mm diameter) within the top 15 cm soil depth. Results showed the mean FRB was significantly higher in undisturbed areas (7.77 t/ha) compared to disturbed (7.053 t/ha) and roadside (1.76 t/ha) areas. Across all sites, FRB exhibited a positive correlation with soil moisture content. Soil pH was slightly more acidic in undisturbed versus disturbed and roadside areas. Soil temperature demonstrated a positive correlation with FRB in undisturbed and roadside areas but a negative correlation in disturbed areas. Additionally, FRB negatively correlated with sand content in disturbed and roadside areas. The findings highlight how soil moisture is a key driver of fine root proliferation in this grassland ecosystem. Variations in soil texture, pH, and temperature between sites reveal their influence on root growth dynamics. Understanding these root-soil interactions has implications for sustainable grassland management, biodiversity conservation, and ecosystem resilience under changing environmental conditions.

Scenic degradation and visual pollution along the Agadir coastline (Morocco): Analysis and management

Visual pollution refers to the degradation of landscape aesthetics, manifesting as visible deterioration. On the Agadir coast in Morocco, factors such as urbanization, erosion, marine wracking, litter, sewage, beach driving, and animal waste contribute to this issue, which detracts from coastal scenery. This study employs the coastal scenery evaluation system (CSES) to conduct a scenic assessment of 40 coastal sites, aiming to describe the current state of visual pollution and inform management interventions. The CSES utilizes a checklist comprising 18 physical and 8 human parameters to calculate a scenic evaluation index (D value), which categorizes coastal sites into five classes. These range from Class I — typically undisturbed natural areas with pristine scenic qualities — to Class V — which are degraded natural areas significantly impacted by human activities. The scenic evaluation classified these sites into three classes. Four sites (10 %) were classified as Class III, fifteen (37.5 %) as Class IV, and twenty-one (52.5 %) as Class V. No sites were classified as Classes I or II. The assessments presented here offer a comprehensive overview of the Agadir coastal scenery and establish a baseline for developing strategies to address visual pollution.

Bridging biodiversity and gardening: Unravelling the interplay of socio-demographic factors, garden practices, and garden characteristics

The expansion of urban areas threatens biodiversity and disrupts ecological relationships, thereby impeding key ecosystem services. To avert irreversible consequences, there is a focus on improving the biodiversity value of domestic gardens. We employ machine learning and network analysis and examine gardening practices and garden owners’ environmental consciousness in Hungary through a questionnaire-based study to untangle the interplay among socio-demographic factors, garden management and -characteristics. We found that the activities determined as biodiversity-positive were widespread among respondents, but ubiquitous pesticide use (62.14%), lack of undisturbed areas (49.52%), and frequent mowing (32.06%) were also present. Middle-aged respondents demonstrated more biodiversity-supporting activities than those over 55, who had long-term gardening experience and were predominantly conventional gardeners. Respondents of towns showed the least biodiversity-positive activities, whereas those living in cities and the countryside fared better. Additionally, multiple interconnected garden characteristics revealed various types of gardens distinguished by care practices and use, such as gardens for food self-provisioning, ornamental gardens, or those prioritizing biodiversity support. Our results show that garden owners use pesticides independently of socio-demographic parameters, gardening practices, or garden characteristics, suggesting widespread pesticide use in Hungary. Our findings suggest that strategies to promote biodiversity-friendly gardening may not be equally suitable for all gardener owners with different cultural backgrounds, environmental consciousness and gardening habits. Factors like differences between societal groups underscore the preference for in-person programs over online information transfer in several cases, for instance, among the elderly and those living in the countryside. We offer fresh perspectives on the intricate connections between garden diversity, characteristics, and practices, and it lays the groundwork for future research into the sociological drivers of gardening practices in Eastern Europe. Our work emphasises that optimizing gardens for multiple ecosystem services, including biodiversity conservation and enhancing human well-being, requires a nuanced understanding of both ecological and socio-demographic factors.

Rainfall and soil properties driver the temporal dynamics of arbuscular mycorrhizal fungal assemblages in a seasonally dry tropical forest

The Seasonally Dry Tropical Forests (SDTF), distributed from Mexico to northern Argentina, are habitat to a unique biodiversity. Among these forests, the Caatinga stands out, occupying a large part of the Brazilian Northeast and is subject to cycles of anthropic disturbance and abandonment of exploited areas. Understanding how microbial communities respond to environmental changes is crucial, especially considering the various ecosystem services provided by microorganisms. Among soil microorganisms, arbuscular mycorrhizal fungi (AMF) play a significant role in the maintenance of terrestrial ecosystems. In this study, we aimed to evaluate the structure, composition, and distribution of AMF assemblages, as well as their main drivers, in regeneration areas of the Caatinga. Soil samples were collected in the Catimbau National Park (Pernambuco State), including an old-growth forest representing undisturbed areas, and in early, intermediate, and late regeneration areas. The composition of AMF assemblages differed among regenerating areas and old-growth forest, but their distribution is not related and conditioned to plant assemblages. Instead, soil properties and rainfall are the main factors structuring these assemblages in SDTF. A total of 83 taxa of AMF were identified. Glomus and Acaulospora, which exhibit respectively ruderal and stress-tolerant life strategies were the most abundant genera. The highest number of unique AMF species was recorded in the old-growth forest, contrasting with the late regeneration areas which had the lowest number. The results showed that deterministic processes (soil and rainfall) are structuring the AMF assemblages in areas under regeneration process in SDTF. Plants and AMF do not recover simultaneously over the evaluated regeneration times.

Nexus between carbon stock, biomass, and CO2 emission of woody species composition: evidence from Ise-Ekiti Forest Reserve, Southwestern Nigeria

The carbon stock, biomass, and CO2 emissions in woody species play crucial roles in understanding and managing ecosystems. Understanding these aspects is crucial for sustainable forest management, conservation, and mitigating the impact of woody species on global carbon dynamics and climate change. This study examined the nexus between carbon stock, biomass, and CO2 emission of woody plant composition in disturbed and undisturbed areas in Southwestern Nigeria. The study involved the random establishment of plots in the disturbed and undisturbed areas and, in each plot, the woody plants were enumerated and identified to the species level. The results showed that total biomass (102.645 Mg ha-1), total carbon stock (51.323 Mg C ha-1), and total CO2 emission (188.354 Mg C ha-1) values of tree species in undisturbed plots were higher than the values of total biomass (70.768 Mg ha-1), total carbon stock (35.384 Mg C ha-1), and total CO2 emission (129.859 Mg C ha-1) recorded in disturbed plots. The results also revealed that total biomass (0.123 Mg ha-1), total carbon stock (0.061 Mg C ha-1), and total CO2 emission (0.225 Mg C ha-1 ) values of shrub species recorded in disturbed plots were higher than values of total biomass (0.067 Mg ha-1), total carbon stock (0.034 Mg C ha-1) and total CO2 content (0.124 Mg C ha-1) recorded in undisturbed plots, respectively. The findings showed that in undisturbed and disturbed plots of shrubs, biomass, carbon and CO2 emissions have a strong positive correlation of 1.000**. While biomass, carbon, and CO2 emission have a very strong positive correlation (0.999**) in undisturbed plots of trees, the biomass, carbon, and CO2 emission have moderate to strong positive correlations (0.458** to 0.974**) in disturbed plots of the tree. The study concluded that while biomass, carbon stock, and CO2 emission values of tree species were higher in undisturbed plots than in disturbed plots, the biomass, carbon stock, and CO2 emission values of shrub species were lower in undisturbed plots than in disturbed plots. It also concluded that the main purpose of establishing reserve forests is not totally achieved as human activities occurring in reserve forests still contribute to the increment of climate change.

A case study on the function of turf algae as suitable habitat for peracarid crustaceans in disturbed environments from SW Mediterranean Sea

ABSTRACT In the summer of 2014, a field study was carried out in four coastal rocky bottoms from the southeast coast of Spain. In this region, dense canopies of Ericaria mediterranea characterize the undisturbed areas and cover much of the infralittoral stage. Turfs composed of the coralline algae Ellisolandia elongata replace the canopy in places where any anthropogenic disturbance occurs. The main objective of this study was to compare the peracarid fauna inhabiting within the two types of phytal substrate, and to conduct several statistical analyses to detect significant differences between the two assemblages. Contrary to expected, the analyses showed that in E. elongata there was a higher population density of peracarids, as well as higher species richness and values for α-diversity indexes. However, none of these differences was statistically significant, although site-to-site comparison indicated greater differences between locations with the same physical cover. The data pointed out that the assemblage that inhabits the coralline turfs in the area was not an impoverished version of that found in pristine locations, so these algae can act as a suitable habitat for peracarids in case of mild human disturbance.

Identification and biocontrol potential of entomopathogenic nematodes, Steinernema siamkayai occurring in western Thailand against the common cutworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae) under laboratory and screenhouse conditions

AbstractThe common cutworm, Spodoptera litura, is a serious insect pest of many vegetables and crops worldwide. Entomopathogenic nematodes (EPN) have been utilized as biological control agents for controlling various insect pests, including the larvae of S. litura. Many indigenous EPN have been recognized to be more effective in specific field applications. Among the 160 soil samples collected in undisturbed areas of western Thailand, three samples tested positive for EPN. Three indigenous EPN were identified as Steinernema siamkayai namely, EPNKU63, EPNKU70 and EPNKU85, based on ITS and D2/D3 expansion region analysis of the 28s rRNA genes. Additionally, genetic analysis of the symbiotic bacteria using recA rRNA sequences confirmed their identity as Xenorhabdus stockiae namely, PEPNKU63, PEPNKU70 and PEPNKU85. To evaluate their initial biocontrol potential against the 6th instar larvae of Galleria mellonella, virulence assays were conducted. The application of 100 infective juveniles (IJs)/insects resulted in the mortality of 80–100% of G. mellonella larvae after 72 h. When symbiotic bacteria were applied at 1 × 106 cells/insect, they exhibited 63–93% mortality against G. mellonella larvae after 120 h. In further laboratory tests, three S. siamkayai isolates achieved 100% mortality of 3rd instar Spodoptera litura larvae within 72 h, with LC50 values ranging from 29 to 30 IJs/insect. In screenhouse experiments, it was revealed that all S. siamkayai isolates displayed substantial virulence, ranging from 62% to 74%, against 3rd instar S. litura larvae within 72 h. This study demonstrates the biocontrol potential of S. siamkayai in controlling S. litura larvae.

Temperature-driven homogenization of an ant community over 60 years in a montane ecosystem.

Identifying the mechanisms underlying the changes in the distribution of species is critical to accurately predict how species have responded and will respond to climate change. Here, we take advantage of a late-1950s study on ant assemblages in a canyon near Boulder, Colorado, USA, to understand how and why species distributions have changed over a 60-year period. Community composition changed over 60 years with increasing compositional similarity among ant assemblages. Community composition differed significantly between the periods, with aspect and tree cover influencing composition. Species that foraged in broader temperature ranges became more widespread over the 60-year period. Our work highlights that shifts in community composition and biotic homogenization can occur even in undisturbed areas without strong habitat degradation. We also show the power of pairing historical and contemporary data and encourage more mechanistic studies to predict species changes under climate change.

Mapping alien and native forest dynamics in Chile using Earth observation time series analysis

Chile is a global biodiversity hotspot and hosts a large proportion of the southern hemisphere’s temperate forests. The Chilean Valdivian temperate forest is a vulnerable ecosystem containing a highly ecologically valuable species assemblage. Productive forest plantations have involved deforestation of, and alien species introduction into, this ecosystem. This process has already severely impacted the western part of Chile (the Coastal Range) and is now occurring in the eastern part (the Andes), with forestry plantations promoted by government subsidies between 1974 and 2012. Archive Landsat satellite imagery classification and Google Earth Engine are used to assess land cover change over a 31-year period with a focus on alien species (Pinaceae and Eucalyptus spp.) spread and native (Nothofagus spp. and Araucaria araucana) deforestation. Results show a clear land cover pattern based on elevation: a higher altitude, relatively undisturbed area dominated by native forest (the Andes), and a lower altitude area where most human activity and related land covers are located (the valley area). The valley is highly dynamic because of constant land cover change due to forestry. Overall, Araucaria araucana cover has decreased over the study period, while Nothofagus spp. has remained relatively stable. Alien Pinaceae has decreased, while Eucalyptus spp. has remained stable. However, the results indicate that change analysis over long periods conceal dynamism. For example, Eucalyptus spp. sharply decreased between the 1980s and the 1990s and surged afterwards. Also, even though Nothofagus spp. cover dominates throughout the study period, change analysis shows a high degree of change in the valley area, indicating newly established Nothofagus spp. patches. Over the study period, long rotation Pinaceae plantations for timber have given way to shorter rotation forestry (alien Eucalyptus spp., native Nothofagus spp.) for pulp and local uses resulting from discontinuation of forest subsidies. In the absence of subsidies, only large-scale plantations can engage in long rotation forestry, as smallholders need the more stable income provided by shorter rotation forestry. Although higher elevations (the Andes) are dominated by native forest, several abandoned alien forest plantations may be the source of biological invasion. In addition, native forest degradation as a result of Araucaria araucana loss and shrub encroachment is occurring. Earth observation methods are key for forest and alien species monitoring and landscape management. They can enhance traditional, ground-based forest surveys and provide continuous and even retrospective monitoring of forest change thanks to the wide availability of current and historical satellite data.