Ecotonal Areas Research Articles

The True Mangroves of Bintuni Bay, Indonesia with Special Notes on the Existence of Amyema mackayensis (Blakely) Danser and Brownlowia argentata Kurz

This research aimed to identify true mangroves in the ecotone area of Bintuni Bay, West Papua, Indonesia. It applied a plotless transect sampling method to identify two true mangroves previously unknown to the area, namely Amyema mackayensis and Brownlowia Argentina. The presence of the species in Bintuni Bay extended its distribution to the northern area of Indonesian New Guinea. With the addition of these two new records, Bintuni Bay hosted 30 species of true mangroves.

Anurans in the ecotone between the Atlantic Forest and Cerrado in the Campos das Vertentes, southeast Brazil

Knowing the biodiversity of anurans in poorly studied regions, especially those in biomes declining in areaas a result of human activities, such as the Campos das Vertentes in Minas Gerais, Brazil, is essential for developing andimplementing management and conservation strategies for the biota and for monitoring environmental quality. Ourobjective was to inventory the anurans of forest remnants in an ecotonal area between Atlantic Forest and Cerrado inBarroso and Prados Municipalities, Minas Gerais, Brazil. From October 2020 to March 2021, four researchers sampledanurans during three nighttime hours over 24 days for a total of 168 person-hours. We recorded 26 anuran species (16in the Family Hylidae) in 13 genera and seven families. Forest fragments, such as those sampled, are important for theprotection of anurans but are disappearing rapidly, mostly due to conversion to agricultural activities. Reduction oreven local extinctions of anuran populations renders conservation actions urgent.

Alternative vegetation trajectories through passive habitat rewilding: opposite effects for animal conservation

ContextPassive habitat rewilding after rural abandonment can affect wildlife differently depending on the type of habitats that it generates.ObjectiveEvaluate and compare the effects of two alternative vegetation trajectories that occur through passive habitat rewilding in Mediterranean ecotone areas (crop-scrub and crop-pine forest transitions) on the long-term population dynamics of animal species.MethodsWe used the spur-thighed tortoise (Testudo graeca), a characteristic long-lived species of cultural landscapes, as study species. We applied a spatially explicit and individual-based model (STEPLAND) to simulate the movement and demographic processes in a long-term period, by comparing an “impact scenario” (i.e., historical land-use changes) to a “control scenario” (no land-use changes).ResultsThe two landscape scenarios resulted in different population trends. In the crop-scrub scenarios (control and impact), population densities increased similarly over time. However, the crop-pine forest scenario negatively affected population density throughout the simulation period, and showed a time-lag response of three decades. The extinction risk was 55% with a time-lag response of approximately 110 years.ConclusionsOur study highlights the need to analyse the legacy effects on long-lived ectotherms, using them as a proxy to understand the future effects of dynamic landscapes created by “passive habitat rewilding”. Our results showed how traditional agriculture in Mediterranean ecotone areas may generate “ecotone effects” (i.e. increase in demographical parameters), but also population extinction on long-lived ectotherms. Therefore, we consider it relevant to maintain traditional agricultural areas in Mediterranean landscapes, especially in ecotone areas associated with pine forests (generating mosaics with open habitats).

Seasonal and Ecological Determinants of Wild Boar Rooting on Priority Protected Grasslands

Wild ungulates can influence various trophic levels, regulating carnivore abundance and affecting habitat structure. Conservation problems can arise when high ungulate densities threaten species or habitats with conservation concern. Assessing factors influencing the intensity of their impact is important to identify appropriate measures enhancing habitat conservation. We assessed factors influencing wild boar Sus scrofa pressure on EU protected grasslands in three protected areas of central Italy, by modelling the effects of environmental variables and wild boar density on rooting activity. We seasonally estimated rooting in 126 sampling plots from spring 2019 to spring 2021, and we used faeces counts to estimate summer wild boar densities. Estimates of density and rooting varied from 3.5 to 22.2 individuals/km2 and from 1.1 to 19.2%, respectively. We detected a clear seasonal trend in rooting activity, that peaked in autumn and winter. We also found a strongly positive correlation between spring-summer rooting and summer density, across sites. Rooting intensity was negatively related to the local extent of rock cover and increased with the 1 month-cumulative rainfall, the perimeter of the grassland patch, and the forest cover around plots. These results emphasise the tendency of wild boar to exploit feeding sites in ecotonal areas, i.e., at the interface between forest and meadows, which maximises security and ease of finding food resources. Actions aiming at the protection of focal plants in grassland habitats, as well as reducing wild boar presence, are supported (e.g. fencing and/or targeting population control at vulnerable patches).

Ecosystem health assessment using multi-criteria approach in a forested ecotone area in northwest Iran

Assessing and monitoring ecosystem health are critical components of ecosystem management as they provide information on natural resource destruction and the causes and factors leading to it. The need for comprehensive and multidimensional indices for assessing and predicting the status of ecosystems has become increasingly important. The ecosystem health index (EHI) was calculated by assessing multiple criteria, including vigor, organization, and resilience criteria, in an ecotone ecosystem in Ardabil province. Different weighting approaches were used to evaluate the index value, and sub-watersheds were prioritized based on the index weighting. The EHI values varied among the studied sub-watersheds, ranging from 0.32 to 0.79, depending on the weighting method. Sub-watershed SW1 had a higher health status with a value of 0.77 compared to other studied sub-watersheds in the Iril watershed, while SW5 had a lower health status with a value of 0.34 in the equal weighting approach. The average value of the EHI for all studied sub-watersheds in the Iril watershed was found to be 0.50, indicating a relatively undesirable ecosystem health status. The EHI is a useful tool for prioritizing areas and an effective step in ecosystem management, considering the multidimensional nature of the index and the factors affecting ecosystem restoration or destruction. Assessing the extent of ecosystem degradation across various regions depends on the health status of the studied ecosystem, the feasibility of index calculation, and may involve different selection criteria.

Licófitas e samambaias de um ecótono Amazonia-Cerrado no estado do Maranhão, Nordeste do Brasil: chave de identificação de lista anotada dos táxons

Abstract We present a key to identify and an annotated list of lycophytes and ferns of the Immediate Geographical Region of São Luís, Maranhão State, which has ecotonal characteristics of Amazonian Forest, Cerrado, and Coastal Vegetation. Specimens were collected monthly between April 2020 and September 2022 in the 13 municipalities of this region. A total of 64 species were identified, including 61 species of ferns, in 18 families and 38 genera, and three species of lycophytes, in two genera and one family. The most representative families were Pteridaceae (18 species) and Polypodiaceae (nine species). The most recorded substrate of occurrence was terrestrial with 35 species (54.6%), followed by epiphytic with 15 species (23.4%), aquatic with four species (6.2%), rupicolous with three species (4.6%), and hemiepiphytic with two species (3.1%). Five species (7.8%) had more than one life form. This study expands the knowledge about the geographic distribution of fern and lycophyte species in the central region of Northern Maranhão, in Northeastern Brazil, which until now had several sampling gaps. Maranhão has a diversity that is still poorly reported and known compared to other states in South and Southeast Brazil. Therefore, floristic surveys are essential to increase what is known about the flora, especially in areas under anthropic pressure and places with few collections, such as the ecotonal areas in Maranhão.

Retrieving biodiversity data from multiple sources: making secondary data standardised and accessible.

Biodiversity data, particularly species occurrence and abundance, are indispensable for testing empirical hypothesis in natural sciences. However, datasets built for research programmes do not often meet FAIR (findable, accessible, interoperable and reusable) principles, which raises questions about data quality, accuracy and availability. The 21st century has markedly been a new era for data science and analytics and every effort to aggregate, standardise, filter and share biodiversity data from multiple sources have become increasingly necessary. In this study, we propose a framework for refining and conforming secondary biodiversity data to FAIR standards to make them available for use such as macroecological modelling and other studies. We relied on a Darwin Core base model to standardise and further facilitate the curation and validation of data related including the occurrence and abundance of multiple taxa of a region that encompasses estuarine ecosystems in an ecotonal area bordering the easternmost Amazonia. We further discuss the significance of feeding standardised public data repositories to advance scientific progress and highlight their role in contributing to the biodiversity management and conservation.

Multiple stable isotopes and geochemical approaches to elucidate groundwater reactive transport paths in mining cities: A case from the northern Anhui, China

Mining cities are ecotone areas where human and natural components interact. Indeed, the negative effects of mining activities on drinking water quality have become a serious public concern worldwide. To elucidate groundwater genesis and reactive transport path controlling the water pollution, a multi-bodies system in the Sunan Mine area in China was considered in this study. The results of the mineral phase characterizations, hydrochemical analysis, and multiple stable isotopes (δ2H/δ18O, δ34S and 87Sr/86Sr) indicated that calcite, dolomite, gypsum, quartz, halite, organic carbon, and gases (O2, CO2 and H2O) were the primary reactants in the aquifer system, accompanied by dissolution and precipitation of minerals, cation exchange, desulfation, and evaporation. An inverse hydrogeochemical model was employed to identify three paths, Path 1 demonstrated that mine water mainly originated from the Quaternary loose aquifer water (QLA), Permian fractured sandstone aquifer water (PFA), and Carbonifer fractured limestone aquifer water (CFA), accompanied by high K++Na+ and HCO3− concentrations due to the carbonate dissolution, halite dissolution, and cation exchange processes. Path 2 showed that the recharge of the CFA and Ordovician fractured limestone aquifer (OFA) occurred from the shallow recharge zone to the deeper OFA water through faults and fractures, mainly involving halite dissolution, carbonate dissolution, and gypsum dissolution. Path 3 demonstrated the interaction between the Hui River, collapsed pond water, and QLA, accompanied by gypsum dissolution, calcite dissolution, and cation exchange. Although the shallow QLA quality met the WHO drinking water standards, the pollution risk from the surface collapse pit water cannot be ignored. Therefore, effective approaches need to be considered in the study area to reduce the connection between the collapse pit water and QLA. The study results can help decision makers to predict water quality of complex water systems in ecotone areas and other similar regions worldwide.

Predicting the future of threatened birds from a Neotropical ecotone area.

Climate change affects ecosystems in different ways. These effects are particularly worrying in the Neotropical region, where species are most vulnerable to these changes because they live closer to their thermal safety limits. Thus, establishing conservation priorities, particularly for the definition of protected areas (PAs), is a priority. However, some PA systems within the Neotropics are ineffective even under the present environmental conditions. Here, we test the effectiveness of a PA system, within an ecotone in northern Brazil, in protecting 24 endangered bird species under current and future (RCP8.5) climatic scenarios. We used species distribution modeling and dispersal corridor modeling to describe the priority areas for conservation of these species. Our results indicate that several threatened bird taxa are and will potentially be protected (i.e., occur within PAs). Nonetheless, the amount of protected area is insufficient to maintain the species in the ecotone. Moreover, most taxa will probably present drastic declines in their range sizes; some are even predicted to go globally extinct soon. Thus, we highlight the location of a potentially effective system of dispersal corridors that connects PAs in the ecotone. We reinforce the need to implement public policies and raise public awareness to maintain PAs and mitigate anthropogenic effects within them, corridors, and adjacent areas, aiming to conserve the richness and diversity of these already threatened species.

Conserving localized endemic butterflies through demographic and ecological studies: Polyommatus humedasae

1.Polyommatus humedasae is an endemic species narrowly distributed in a few sites in the Aosta Valley (NW Italy). Similarly to other alpine butterflies, the survival of the species is closely linked to the conservation of semi-natural grasslands.2.Despite the species being known since 1976, this is the first comprehensive data collection and analysis on this species, firstly to understand its distribution. At Pont d'Ael, the species core site, we applied the mark-release-recapture (MRR) method to estimate population size and density. To understand the species ecology, we collected data on preimaginal stages (eggs and larvae), host plants, and vegetation composition.3.The new data on species distribution (with 5 new sites and 2 subpopulations already extinct) permitted to update the extinction risk through IUCN assessment to Critically Endangered (CR). The estimated size (881 individuals) and density (73 N/ha) of the studied population are higher than those of other endemic Polyommatus species. Data suggest the species is monophagous on Onobrychis arenaria and prefers to lay eggs where the host plant is abundant, in ecotonal areas with some shrub cover (average 8 %), high herbaceous cover (average 68 %) and on plants in better physiological conditions.4.For species such as P. humedasae, which are threaten by woody encroachment, climate change, fires and collection, we propose the application of a management plan that includes: 1) mechanical cut of wood species; 2) small herds on a rotational basis to reduce woody encroachment and maintain shrub patches; 3) dissemination events to highlight the population importance.

Discovering the diversity of tadpoles in the mid-north Brazil: morphological and molecular identification, and characterization of the habitat.

Brazil stands out for presenting the highest amphibian anuran diversity in the world. However, taxonomic studies that address characteristic of larval stage of anurans are incipient, representing only 62% of known species. We assess the species diversity of tadpoles from eastern Maranhão state, mid-northern region of Brazil based on morphological and molecular identification (i.e., 16S rRNA gene fragment), and we also provide characteristics of the habitats occupied by each species. We carried out 30 field samplings during 13 months in 16 environments along an ecotonal area, over five cities inside the limits of state of Maranhão, between the Maranhão Babaçu Forest and Cerrado ecoregions. We searched for tadpoles in a variety of water bodies, and the tadpoles that reached the developmental stage between 34 to 40 Gosner were morphologically identified. The tadpoles collected herein represent 26 species belonging to five families. The external morphology enabled the identification of 24 species, while the molecular data recognized 22 unique evolutionary units. The most represented family was Hylidae (Hylinae 11 spp., Phyllomedusinae one spp.) followed by Leptodactylidae (Leptodactylinae seven spp., Leiuperinae three spp.), Microhylidae (Gastrophryninae two spp.), and Bufonidae (two spp.). Our results show that oral morphology was the most important character for identifying tadpoles based on morphology, and the specific 16S rRNA primer was suitable for molecular identification. This study pioneers the use of both morphological and molecular data to identify tadpoles in the state of Maranhão. It also provides, for the first-time, habitat characteristic for the species. Our study reveals a high number of anuran species sampled at the larval stage in the region, identifies species that require further taxonomic and systematic attention, and extends the geographic distribution of six species, three of which represent new occurrences for the state. Our results strengthen the hypothesis that the diversity of amphibians from Maranhão is underestimated and highlight the importance of herpetological inventories in poorly sampled areas, decentralizing the knowledge of biodiversity.

The Resistance of Waters to Trophic Growth as a Result of Processes in Their Ecotone Areas (According to Phytoplankton Indicators)

The Resistance of Waters to Trophic Growth as a Result of Processes in Their Ecotone Areas (According to Phytoplankton Indicators)

The Resistance of Waters to Trophy Increases as a Result of Processes in Their Ecotone Areas (according to Phytoplankton Indicators)

According to the saprobity index, estimated by the phytoplankton biomass, the degree of organic pollution of ecotone areas (the mouth of the Il’d River and the littoral of the Volga reach of the Rybinsk reservoir) was determined. The saprobity index in protected shallow waters was 1.83 in 2009 and 2.07 in 2010; in the pelagial – 2.14 and 2.13 in 2009 and 2010 respectively. In the “river-reservoir” system, the lowest average values of the saprobity index were noted in the mouth area of the Il’d River: in 2009 – 1.94, in 2010 – 1.87, in 2011 – 1.88. In the river and the reservoir, its values were higher: 2.05 and 2.07 in 2009, 1.96 and 2.08 in 2010, and 1.97 and 1.99 in 2011 respectively. The decrease in saprobity in shallow waters and at the mouth of the river, compared to the bordering water, indicates a higher intensity of self-purification processes, which can ensure the sustainability of the ecosystem of the reservoir as a whole. Abnormal weather phenomena, in particular, high summer water temperatures, can lead to destabilization of the features of ecotone algocenoses, as a result, to a violation of the process of self-purification of the reservoir.

Butterfly Diversity in the Campus area of University of North Bengal, West Bengal, India.

Butterflies play a crucial role as bio-indicators, signaling the health of ecosystems and biodiversity, making their conservation vital. The northern region of West Bengal in eastern India is renowned for its remarkable butterfly diversity. The University of North Bengal campus, spanning 315.99 acres at the Eastern Himalayan foothills (26°42′34.03″N; 88°21′14.96″E), is home to diverse flora and fauna. The surrounding area offers a variety of habitats, including forests, grasslands, tea gardens, and wetlands, which support numerous animal species. This study aimed to assess butterfly diversity in three distinct geographical sites within the university campus: the Tea garden area (dominated by tea and rubber plants), Salkunja (a forested area with a semi-perennial stream dominated by Sal trees), and Magurmari (an area with semi-perennial streams, ponds, ephemeral water bodies, paddy fields, and grasslands). Monthly butterfly observations were conducted from December 2021 to January 2023. The study documented 55 butterfly species from six families (Hesperiidae, Lycaenidae, Nymphalidae, Papilionidae, Pieridae, and Riodinidae), with Nymphalidae being the most prevalent and Riodinidae the least. Notably, the ecotone area of Magurmari exhibited the highest butterfly species diversity. Four species protected under the Wildlife (Protection) Act (WPA), 1972, were also identified. This research aims to analyze butterfly diversity in relation to their habitats and conservation needs within the university campus, contributing to the development of a concise checklist specific to this district for effective conservation efforts. The study underscores the significant butterfly diversity found on the campus, emphasizing the urgent need for focused conservation actions.

Examining Drivers of Post-Fire Seismic Line Ecotone Regeneration in a Boreal Peatland Environment

Seismic lines are the dominant anthropogenic disturbance in the boreal forest of the Canadian province of Alberta, fragmenting over 1900 km2 of peatland areas and accounting for more than 80% of all anthropogenic disturbance in this region. The goal of this study is to determine whether the wildland fires that burn across seismic lines in peatlands result in the regeneration of woody vegetation within the ecotonal areas adjacent to seismic lines. We use a combination of seismic line and vegetation structural characteristics derived from multi-spectral airborne lidar across a post-fire peatland chronosequence. We found an increasing encroachment of shrubs and trees into seismic lines after many years since a fire, especially in fens, relative to unburned peatlands. Fens typically had shorter woody vegetation regeneration (average = 3.3 m ± 0.9 m, standard deviation) adjacent to seismic lines compared to bogs (average = 3.8 m ± 1.0 m, standard deviation), despite enhanced shrubification closer to seismic lines. The incoming solar radiation and seismic line age since the establishment of seismic line(s) were the factors most strongly correlated with enhanced shrubification, suggesting that the increased light and time since a disturbance are driving these vegetation changes. Shrub encroachment closer to seismic lines tends to occur within fens, indicating that these may be more sensitive to drying conditions and vegetation regeneration after several years post-fire/post-seismic line disturbance.

New record of Spot-Legged Turtle, Rhinoclemmys punctularia (Daudin, 1801) (Reptilia, Testudines, Geoemydidae), from an Amazon ecotonal zone in the Tocantins–Araguaia river basin, Brazil

We report a new record of Rhinoclemmys punctularia (Daudin, 1801), extending the geographic dis-tribution of this species by 450 km towards the south to the Araguaia River in the state of Pará, Brazil. The new record comes from an ecotonal area of the Cerrado and Amazon biomes, which indicates a possible adaptability of this species in fragmented environments and in agricultural areas. These new findings help enable future investi-gations better understand the distribution of R. punctularia in the southern Amazon Basin and in ecotones.

Suitability evaluation of the rural settlements in a farming-pastoral ecotone area based on machine learning maximum entropy

The suitability evaluation of rural settlements is the core foundation of planning and layout optimization. Settlements in a farming-pastoral ecotone are migrative, dynamic, and diverse, and thus their suitability changes constantly. However, our limited understanding of factors that drive this dynamic process and affect the suitability of humane settlements in the farming-pastoral ecotone hindered the high-quality development of human settlements in such areas. Here we selected the ethnic minority border area of Dalham Maomingan United Banner (DMUB) in the farming-pastoral ecotone of Northern China to evaluate the suitability of its rural settlements. A data-driven machine learning maximum entropy (Maxent) method was applied to the rural settlement datasets of DMUB in years 1996, 2010, and 2020, as well as to 13 influencing factors derived from optical images and topographical ancillary data, demonstrating that the Maxent model can quantitatively measure the contribution and importance of each factor and its variation over time. Furthermore, the results showed that factors such as distance to cultivated land, population density, and distance to road had a great influence on the early-stage distribution of settlements. However, the importance of cultivated land gradually decreased with the significantly increased effect of grassland in the later period. The influence of road factors fluctuated first increasing and then decreasing. The Maxent model was also used to automatically determine suitable range for each factor according to the response curve: elevation falling between 1450 and 1650 m approximately, slope being <7°, the aspect range about 75°-225°, the optimal distance to town and hospital being within 3000 m, and vegetation cover about 0.60–0.75. Such multi-period suitability evaluation indicated that the suitable area gradually decreased, and the settlement fragmentation was serious. The settlement suitability has been dynamically transformed, but mostly toward the unsuitable development. This study provides a decision-making basis for the site selection and planning layout of rural settlements and for the livability assessment of villages in the farming-pastoral ecotone.

Floristic similarity of lycophytes and ferns in the Amazonia/Cerrado transition zone in the central region of northern Maranhão state, Brazil

Floristic similarity studies make it possible to compare species richness between different phytophysiognomies and to assess whether species are typical of a phytophysiognomies or if they are common to two or more phytophysiognomies. The Immediate Geographic Region of São Luís (IGR), in the central region of northern Maranhão, is characterized by the presence of Amazonia, Cerrado, and coastal vegetation phytophysiognomies. The objectives of this work were to verify if the fern and lycophyte species in the IGR are similar to those in another Amazonia and Cerrado phytophysiognomies in Maranhão and Brazil. Sixty-three species of lycophytes and ferns were identified, with a predominance of individuals in the families Pteridaceae and Polypodiaceae. A similarity analysis indicated the study area has a greater affinity with the Amazonia. This is the first floristic similarity study that emphasizes ferns and lycophytes in Maranhão. However, the scarcity of floristic surveys in Maranhão and other ecotonal areas in Brazil hindered a more complex analysis of the floristic similarity of these phytophysiognomies.

The king of the Tangarás: a bird indicator of ecotonal areas between two “hotspots”

According to the literature, transition areas, border regions, and the edges of ecological systems where plant and/or animal communities share common elements are considered ecotones. The bird commonly known as the king-of-tangarás is a hybrid between the Chiroxiphia caudata species, endemic to the Atlantic Forest, and the endemic bird of the Cerrado domain, Antilophia galeata. This study compiles and analyzes the recorded areas of this bird. Based on the findings, the objective of this work is to highlight the king-of-tangarás as an indicator of ecotonal regions.

Determinants of the composition of ectoparasitic flies of bats (Diptera: Streblidae, Nycteribiidae) in the Amazon and Cerrado landscape scales and ecotonal areas.

The high diversity of bats in the Neotropics is primarily associated with various ectoparasite species on their bodies. Interactions between these animals need to be comprehensively investigated at landscape scales, focusing on understanding the patterns of diversity of species. We sought to evaluate, througt bat captures and ectoparasite sampling, the determinants of the composition of ectoparasitic flies species present in bats in in the Amazon and Cerrado biomes and ecotone areas. We used a generalized dissimilarity model (GDM) to verify what factors explained the composition of ectoparasitic flies of bats using landscape metrics, geographic distance, biome, and host composition. Twenty-four bat species haboured a total of 33 species of ectoparasitic flies. Host composition was the best predictor of fly composition, followed by the environmental variables and by biome. Geographical distance presented negligible effects. Studies on large scales tend to reveal a wide diversity of ectoparasitic flies. Host composition, as the best predictor of fly composition, may be associated with interspecific characteristics among species. We recommend studies focusing on the landscape to understand better the parasitic associations of bats and their distribution across environments.