Ecoregions Research Articles

Integrative description of a new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Shennongjia, Central China.

A new species of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Xiangxi River, Shennongjia Forestry District, Hubei Province, China, is described on the basis of an integrative approach, involving morphology, and molecular systematics. The new species Dugesia saccaria A-T. Wang & Sluys, sp. nov. is characterized by the following features: a dumb-bell-shaped, muscularized hump located just anterior to the knee-shaped bend in the bursal canal; a ventrally displaced ejaculatory duct, which, however, opens terminally through the dorsal portion of the blunt tip of the penis papilla; a ventrally located seminal vesicle, giving rise to a vertically running duct that eventually curves downwards to communicate with the ejaculatory duct via a small diaphragm; oviducts opening asymmetrically into the dorsal portion of the common atrium and at the knee-shaped part of the bursal canal. The phylogenetic position of the new species was determined using four molecular markers (18S rDNA; ITS-1; 28S rDNA; COI), which suggested that it groups with other species of Dugesia from the Australasian and Oriental biogeographical regions.

Ecological Zoning Based on Value–Risk in the Wuling Mountains Area of Hunan Province

Based on land use data from the Wuling Mountains area of Hunan Province for 2000, 2010, and 2020, we used tools such as frastats4.8 and ArcGIS10.8 to construct a model for assessing ecosystem service value and the ecological risk index. We divided the area into four regions based on ecosystem service value and ecological risk indicators, which served as the foundation for ecological zoning and a proposed strategy for an ecological security pattern that suits the ecology of the region. The results showed a general increase in both ecosystem service value and ecological risk in the study area from 2000 to 2020. The annual ecosystem service value exceeded CNY 300 × 109, with forests providing more than 77% of this value, and the regulating services value accounted for 68% of the total value. The mean ecological risk indexes for the periods of 2000, 2010, and 2020 were 0.0384, 0.0383, and 0.0395, respectively. The sizes of the four zones within the study area remained relatively stable: the ecological barrier zone accounted for more than 53% over three years; the ecological improvement zone, approximately 32%; the ecological control zone comprised 8.62% of the total area in 2000, and this proportion rose to 9.56% in 2020. The ecological conservation zone had the smallest proportion of the total area among the four zones. Our research provides a comprehensive analytical framework for constructing ecological security patterns in other developing countries and offers a new perspective for regional ecological zoning management and conservation planning.

Large-scale cultural heritage conservation and utilization based on cultural ecology corridors: a case study of the Dongjiang-Hanjiang River Basin in Guangdong, China

In the field of world heritage conservation, there has been broad consensus on carrying out heritage conservation research on the basis of spatial integration and interregional and international cooperation. However, there are still many deficiencies in the integration of culture with the environment, regional economic and social development, and the regional, holistic and multimodal conservation and utilization of cultural heritage sites. In China, the Dongjiang-Hanjiang River Basin is a representative area of substantial cultural and ecological value for both Guangdong Province and the whole country. This paper uses the morphological spatial pattern analysis and the minimum cumulative resistance model to integrate cultural ecology sources and establish a cross-regional and large-scale cultural ecology network system that includes 1 main corridor, 22 important corridors and 17 secondary corridors. In addition, based on identified cultural landscape nodes and cultural ecology services, the economy of the cultural ecology corridor could be developed with large-scale co-construction, co-governance and shared working mechanisms to overcome administrative limits and realize the conservation and utilization of multimodal and large-scale heritage sites. This approach has strong theoretical and practical significance for innovative methods in cultural ecology research, as well as for new content in the research of Lingnan culture, ecosystem restoration, and the economic and social development of towns and villages. This article supplements unilateral studies of regional culture and ecology and demonstrates an in-depth application of cultural ecology theory.

Effects of climate and environmental heterogeneity on the phylogenetic structure of regional angiosperm floras worldwide

The tendency of species to retain ancestral ecological distributions (phylogenetic niche conservatism) is thought to influence which species from a species pool can persist in a particular environment. Thus, investigating the relationships between measures of phylogenetic structure and environmental variables at a global scale can help understand the variation in species richness and phylogenetic structure in biological assemblages across the world. Here, we analyze a comprehensive data set including 341,846 species in 391 angiosperm floras worldwide to explore the relationships between measures of phylogenetic structure and environmental variables for angiosperms in regional floras across the world and for each of individual continental (biogeographic) regions. We find that the global phylogenetic structure of angiosperms shows clear and meaningful relationships with environmental factors. Current climatic variables have the highest predictive power, especially on phylogenetic metrics reflecting recent evolutionary relationships that are also related to current environmental heterogeneity, presumably because this favors plant speciation in various ways. We also find evidence that past climatic conditions, and particularly refugial conditions, play an important role in determining the phylogenetic structure of regional floras. The relationships between environmental conditions and phylogenetic metrics differ between continents, reflecting the different evolutionary histories of their floras.

Role of Rare Species on Phytoplankton Size–Abundance Relationships and Size Structure across Different Biogeographical Areas

Phytoplankton guilds are commonly characterised by dominance effects, while the main contribution to biological diversity is given by rare species. Here, we analysed the influence of rare species on taxonomic and functional diversity, which is described by taxa richness and composition, cell size, and size–abundance relationships in phytoplankton guilds. We explore these relationships at global and regional scales by analysing phytoplankton guilds from five biogeographical regions: the Northern Atlantic Ocean (Scotland), the South-Western Atlantic Ocean (Brazil), the South-Western Pacific Ocean (Australia), the Indo-Pacific Ocean (Maldives), and the Mediterranean Sea (Greece and Turkey). We have comparatively analysed the phytoplankton taxonomic diversity of the whole dataset and with the datasets obtained by progressively subtracting taxa occurring in the last 1%, 5%, 10%, and 25% of both numerical abundance and overall biomass. Globally, 306 taxa were identified across five ecoregions with only 27 taxa accounting for 75% of overall numerical abundance and biomass; almost 50% of taxa were lost on every step. The removal of 1% of most rare taxa significantly affected the phytoplankton size–abundance relationships and body-size structure, strongly impacting on small taxa. The progressive removal of additional rare taxa did not further affect phytoplankton size–abundance relationships and size structure.

Biogeographic analysis of population density of white-tailed deer in Mexico: Importance of the Protected Natural Areas and Wildlife Management Units

The white-tailed deer Odocoileus virginianus is the wildlife species with the greatest geographic distribution and economic importance in Mexico. This article presents a biogeographic analysis of the population density of this deer species by federal states, vegetation types, biogeographic provinces, and field methods, based on 200 selected studies. Estimates are highly variable and potentially biased due to the different field designs and statistical analyses. The national average density was estimated at 6.9 deer/km2 (SD = 5.1); specifically, 75.5 % of the estimates were less than 10 deer/km2, and only 5.5 % were greater than 15 deer/km2. The highest densities were obtained in the northern region by applying the strip transect counts; while estimations using the fecal group count method were more variable and were the most used method in temperate and tropical dry forest regions. The states with the highest densities were Coahuila, Tamaulipas, Jalisco, Morelos, Michoacán, and Durango. The highest densities were estimated in the xerophilous scrublands of the northeast, intermediate for temperate, tropical dry, and sub-deciduous forests; and the lowest in the tropical wet forest. The highest densities were reported for the Tamaulipeca province followed by the Altiplano Chihuahuense, Sierra Madre Occidental, Costa Pacífica, and Depresión del Balsas. The results of this analysis could guide management strategies for the conservation and sustainable use of this species in extensive UMAs and ANPs, and also to test ecological hypotheses. However, applying more rigorous field design and statistical analysis is important to obtain confident estimates of population density and other demographic parameters to monitor population dynamics.

The geno-geo-climate nexus: contributions of geographic and ecological factors in shaping the genomic divergence of two closely related threatened rainforest species of Fontainea Heckel (Euphorbiaceae)

ContextProcesses that shape genomic and ecological divergence can reveal important evolutionary dynamics to inform the conservation of threatened species. Fontainea is a genus of rainforest shrubs and small trees including critically endangered and threatened species restricted to narrow, but complex geographic and ecological regions. Several species of Fontainea are subject to spatially explicit conditions and experience limited intra-specific gene flow, likely generating genetic differentiation and local adaptation.ObjectivesHere, we explored the genetic and ecological mechanisms underlying patterns of diversification in two, closely related threatened Fontainea species. Our aim was to compare spatial patterns of genetic variation between the vulnerable Fontainea australis (Southern Fontainea) and critically endangered F. oraria (Coastal Fontainea), endemic to the heterogeneous subtropical region of central, eastern Australia, where large-scale clearing has severely reduced rainforest habitat to a fraction (< 1%) of its pre-European settlement extent.MethodsWe used a set of 10,000 reduced-representation markers to infer genetic relationships and the drivers of spatial genetic variation across the two species. In addition, we employed a combination of univariate and multivariate genome-environment association analysis using a set of topo-climatic variables to explore potential patterns of local adaptation as a factor impacting genomic divergence.ResultsOur study revealed that Coastal Fontainea have a close genetic relationship with Southern Fontainea. We showed that isolation by distance has played a key role in their genetic variation, indicating that vicariance can explain the spatial genetic distribution of the two species. Genotype-environment analyses showed a strong association with temperature and topographic features, suggesting adaptation to localised thermal environments. We used a multivariate redundancy analysis to identify a range of putatively adapted loci associated with local environmental conditions.ConclusionsDivergent selection at the local-habitat scale as a result of dispersal limitations and environmental heterogeneity (including physical barriers) are likely contributors to adaptive divergence between the two Fontainea species. Our findings have presented evidence to indicate that Southern and Coastal Fontainea were comprised of distinct genetic groups and ecotypes, that together may form a single species continuum, with further phenotype research suggested to confirm the current species boundaries. Proactive conservation actions, including assisted migration to enhance the resilience of populations lacking stress-tolerant single nucleotide polymorphisms (SNPs) may be required to secure the long-term future of both taxa. This is especially vital for the critically endangered Coastal Fontainea given projections of habitat decline for the species under future climate scenarios.

Research on the Current Situation and Countermeasures of Regional Ecological Agriculture Development in Shaanxi Province

The vigorous development of regional ecological agriculture in Shaanxi Province can effectively solve the problems of resource utilization and environmental protection, promote the adjustment of rural industrial structure and rural revitalization. In order to further promote the development of ecological agriculture in Shaanxi Province, this article focuses on the current situation of regional ecological agriculture development in Shaanxi Province, analyzes the problems existing in the development of regional ecological agriculture in Shaanxi Province, and conducts in-depth analysis from three levels: resource allocation, government supervision, and technological development. It explores the path of sustainable development of ecological agriculture and proposes effective measures to promote the healthy, harmonious, and sustainable development of ecological economy in Shaanxi Province. It also provides ideas and references for the development of ecological agriculture in other regions of China.

New Asian Andrena species, with notes on the subgenus Cnemidandrena (Hymenoptera: Andrenidae).

Asia is the worlds largest continent and comprises most of the Holarctic biogeographic region. The genus Andrena is principally distributed through the Holarctic, but it remains understudied in Asia. The subgenus Cnemidandrena Hedicke, 1933 is distributed across Asia with some species reaching south to the Tibetan Plateau. However, some southern members display an unusual morphology, including A. (Cnemidandrena) kishidai chagyabensis Wu, 1982 (newly recorded for Bhutan, India, and Nepal) and A. (Cnemidandrena) granulitergorum Tadauchi & Xu, 2002 (newly recorded for Nepal). The male of A. granulitergorum is described for the first time, A. (Cnemidandrena) rufina Morawitz, 1876 is reported from Kyrgyzstan, Afghanistan, and Kashmir for the first time, and possible senior synonyms for Asian A. (Cnemidandrena) are suggested. To contribute to an improved understanding of localised Asian Andrena diversity, the following new species are described: A. (Cnemidandrena) textrix sp. nov. from China, A. (incertae sedis) liebigi sp. nov. and A. (Troandrena) monfaredi sp. nov. from Iran, and A. (incertae sedis) quercorum sp. nov. from Turkey. These results further confirm that additional taxonomic work is needed to harmonise Andrena species concepts across the different biogeographic regions of Asia.

Environment and traits affect parasite and host species positions but not roles in flea-mammal networks.

We studied spatial variation in the effects of environment and network size on species positions and roles in multiple flea-mammal networks from four biogeographic realms. We asked whether species positions (measured as species strength [SS], the degree of interaction specialization [d'], and the eigenvector centrality [C]) or the roles of fleas and their hosts in the interaction networks: (a) are repeatable/conserved within a flea or a host species; (b) vary in dependence on environmental variables and/or network size; and (c) the effects of environment and network size on species positions or roles in the networks depend on species traits. The repeatability analysis of species position indices for 441 flea and 429 host species, occurring in at least two networks, demonstrated that the repeatability of SS, d', and C within a species was significant, although not especially high, suggesting that the indices' values were affected by local factors. The majority of flea and host species in the majority of networks demonstrated a peripheral role. A value of at least one index of species position was significantly affected by environmental variables or network size in 41 and 36, respectively, of the 52 flea and 52 host species that occurred in multiple networks. In both fleas and hosts, the occurrence of the significant effect of environment or network size on at least one index of species position, but not on a species' role in a network, was associated with some species traits.

Are fire intensity and burn severity associated? Advancing our understanding of FRP and NBR metrics from Himawari-8/9 and Sentinel-2

Burn severity has been widely studied. Typical approaches use spectral differencing indices from remotely sensed data to extrapolate in-situ severity assessments. Next generation geostationary data offer near-continuous fire behaviour information, which has been used for fire detection and monitoring but remains underutilized for fire impact estimation. Here, we explore the association between remotely sensed fire intensity metrics and spectral differencing severity indices to understand whether and where they describe similar wildfire effects. The commonly used Differenced Normalised Burn Ratio (dNBR) severity index was calculated for Advanced Himawari Imager (AHI − 2 km) and Sentinel-2 (20 m) data and compared to different Fire Radiative Power (FRP) metrics derived from fire hotspot detections from AHI data across Australia. The comparison was implemented through different stratifications based on biogeographical region, land cover, fire type, and percentage of AHI pixel burned (fire fractional cover). The results indicate that FRP and dNBR metrics do not correlate in most scenarios, noting correlations being marginally stronger for hotter fires. However, correlations become significantly stronger when data are grouped using fire type information and fire fractional cover, with correlations peaking (R = 0.75) for large fires that burned 41–60 % of an AHI pixel. In conclusion, remotely sensed fire intensity and severity proxies capture different aspects of wildfire impact, that only correlate with each other after using auxiliary data. Spectral differencing severity metrics have been used extensively during the past decades, however high-frequency fire intensity estimations have the potential to augment the existing information and reveal new ways of characterizing wildfire impact over large areas.

Targeting ocean conservation outcomes through threat reduction

Nations have committed to reductions in the global rate of species extinctions through the Sustainable Development Goals 14 and 15, for ocean and terrestrial species, respectively. Biodiversity loss is worsening despite rapid growth in the number and extent of protected areas, both at sea and on land. Resolving this requires targeting the locations and actions that will deliver positive conservation outcomes for biodiversity. The Species Threat Abatement and Restoration (STAR) metric, developed by a consortium of experts, quantifies the contributions that abating threats and restoring habitats in specific places offer towards reducing extinction risk based on the IUCN Red List of Threatened SpeciesTM. STAR is now recommended as an appropriate metric by recent disclosure frameworks for companies to report their impacts on nature and STAR has seen widespread uptake within the private sector. However, it is currently only available for the terrestrial realm. We extend the coverage of the threat abatement component of the STAR metric (START), used to identify locations where positive interventions could make a large contribution to reducing global species extinction risk and where developments that increase threats to species should be mitigated, to the marine realm for 1646 marine species. Reducing unsustainable fishing provides the greatest opportunity to lower species extinction risk, comprising 43% of the marine START score. Three-quarters (75%) of the global marine START score falls entirely outside the boundaries of protected areas and only 2.7% falls within no-take protected areas. The STAR metric can be used both to guide protected area expansion and to target other actions, such as establishment and enforcement of fishing limits, to recover biodiversity.

Does the Construction of a Power Transmission Line (PTL) in a Coastal Mountainous Area Affect the Regional Ecological Security?—Taking Fujian Tangyuan PTL as an Example

Does the Construction of a Power Transmission Line (PTL) in a Coastal Mountainous Area Affect the Regional Ecological Security?—Taking Fujian Tangyuan PTL as an Example

Synthesis of the land carbon fluxes of the Amazon region between 2010 and 2020

The Amazon is the largest continuous tropical forest in the world and plays a key role in the global carbon cycle. Human-induced disturbances and climate change have impacted the Amazon carbon balance. Here we conduct a comprehensive synthesis of existing state-of-the-art estimates of the contemporary land carbon fluxes in the Amazon using a set of bottom-up methods (i.e., dynamic vegetation models and bookkeeping models) and a top-down inversion (atmospheric inversion model) over the Brazilian Amazon and the whole Biogeographical Amazon domain. Over the whole biogeographical Amazon region bottom-up methodologies suggest a small average carbon sink over 2010-2020, in contrast to a small carbon source simulated by top-down inversion (2010-2018). However, these estimates are not significantly different from one another when accounting for their large individual uncertainties, highlighting remaining knowledge gaps, and the urgent need to reduce such uncertainties. Nevertheless, both methodologies agreed that the Brazilian Amazon has been a net carbon source during recent climate extremes and that the south-eastern Amazon was a net land carbon source over the whole study period (2010-2020). Overall, our results point to increasing human-induced disturbances (deforestation and forest degradation by wildfires) and reduction in the old-growth forest sink during drought.

Identification of intercity ecological synergy regions and measurement of the corresponding policy network structure: A network analysis perspective

The development and governance of modern cities have gradually broken through the boundaries of administrative units. In recent times, with intercity ecological space becoming the focus of a series of development and conservation actions, identifying the intercity ecological synergy regions (maintaining connectivity within the ecological space to ensure the continuity of species migration and landscape) and realizing its collaborative governance has become extremely important to maintain sustainable regional development. Cross-border ecological governance involves many actors and forms a complex relationship network. At present, there are few quantitative evaluation methods for this problem, which limits our ability to manage the ecological space between cities. This paper uses the network method to establish and analyze the related ecological and policy networks in Shenzhen. The study results show that the ecological synergy regions are locally concentrated along the fringes of Shenzhen City, and the links between different levels of actors in the policy network are relatively weak. The action objects of ecological governance designated by different cities form convergence or divergence patterns, making it challenging to organize spatially integrated actions among different cities. Finally, suggestions for structural optimization are proposed concerning the policy network associated with the ecological synergy regions from the aspects of spatial implementation pathways and planning strategies.

A collection and analysis of amphibians and reptiles from Nicaragua with new country and departmental records

Nicaragua is a biodiverse country, but documented herpetological specimens are underrepresented compared to neighboring countries. In 2018 we conducted a collaborative expedition between the University of Michigan Museum of Zoology and Nicaraguan biologists. We visited sites in the Pacific Low&amp;#8209; lands, Caribbean Lowlands, and the Central Highlands, representing the three major biogeographic regions of Nicaragua. We collected specimens of 100 species from a total of 106 encountered. We provide acces&amp;#8209; sion numbers and morphological, genetic, and ecological information for these specimens. We recorded 23 new departmental records and the first country record of Metlapilcoatlus indomitus (Smith &amp; Ferrari&amp;#8209;Castro, 2008), filling gaps in the known distribution of the species within Nicaragua and across Central America. When available for each species, we provide range maps and comparative genetic trees including conspecific reference sequences from the region, making this work a significant addition to existing checklists of the herpetofauna in Nicaragua.

Sovereignty, ecology, and regional imperatives: formulating normative foundations for regional ecological justice

ABSTRACT I will outline four justifications of regional ecological obligations calling for different political authorities to collaborate for ecological reasons: through voluntary agreement between political entities united by an ecological region; by a shared regional history or cultural relations to an ecological region; with reference to ‘place-based’ duties with an ecological basis; or by obligations to an extended set of individual right-holders. None are conclusive reasons but show that there are normative grounds for regional collaboration of separate political authorities. The article contributes to discussion on, despite its practical relevance, a much neglected concept in political philosophy.

A Ten-Year Record Shows Warming Inside the Belize Barrier Reef Lagoon

The Belize Barrier Reef system (BBR) in the western Caribbean’s Gulf of Honduras contains a large region of lagoon coral reef, seagrass and mangrove habitat. As the largest lagoon habitat within the Caribbean, this region experiences differing oceanographic and temperature conditions as compared to deeper offshore areas. The occurrence of several endemic species within the Gulf of Honduras area and inside the Belize lagoon supports the hypothesis that this area is a unique biogeographic region. Consequently, the ecological effects of temperature increase due to global climate change may have a long-term adverse impact on this region’s unique marine species. This study reports an in situ temperature record over a ten-year period (2004–2014) collected from a coral reef offshore of Wee Wee Cay within the South Water Cay Marine Reserve of Belize. There was a steady increase in temperature during the decade.

Soil Composition of the Tovuzchay Basin of Azerbaijan by Ecological Regions

One of the environmental problems that the relevant structures are currently closely addressing is the protection and restoration of soil fertility. In this regard, the effective and correct use of land resources in the region, as well as the protection of agricultural land, have become urgent problems. In order to organize environmental monitoring carried out on the basis of the relevant program, environmental observations of diagnostic indicators of soil fertility were carried out. Tovuzchay river basin is divided into ecological regions: watershed, transit and accumulation areas, the closedness of the territories in relation to other river basins, their separation by natural boundaries (watersheds) are factors that increase the accuracy of observations.

Regional Ecological Security Assessment Based on the Pressure–State–Response Framework: The Demonstration Zone of Yangtze River Delta as an Example

Ecological security is related to human well-being, is closely linked to a region’s sustainable development, and is an essential cornerstone of any national security system. The Demonstration Zone of Green and Integrated Ecological Development (DZGIED) of the Yangtze River Delta is a critical point in implementing the integrated development strategy of the Yangtze River Delta. This paper used the Pressure–State–Response (PSR) framework to evaluate the regional ecological security (RES) in the DZGIED based on multi-source remote sensing and GIS data. And the analysis was conducted from the overall and administrative division perspective. The results show that (1) from 2000 to 2020, the ecological security of the DZGIED shows a slight decline overall. The RES decreased from 0.60 to 0.53. The RES level is kept above the critical security level and needs further improvement. (2) Significant differences in the RES across townships, with more pronounced changes in extreme values. The ecological security status of more than 80% of the townships shows solid positive spatial correlations. The ecological security of the DZGIED is more critical to the central area. (3) Human disturbance is the most important factor causing the decline in ecological security and the impact of environmental safety on the central area is more enormous. (4) The ecological security state of the DZGIED shows an improving trend, but it is still necessary to promote the construction of various demonstration projects. This paper aims to ensure the sustainable development of the DZGIED in the future and to provide guidance for policy formulation on ecological safety in the DZGIED from the perspective of administrative divisions. It also provides a reference for small-scale regional ecological safety evaluation studies such as townships.