Extinction Research Articles

Evolución de la biodiversidad amazónica: una revisión

ABSTRACT Amazonia (defined herein as the Amazon basin) is home to the greatest concentration of biodiversity on Earth, providing unique genetic resources and ecological functions that contribute to ecosystem services globally. The lengthy and complex evolutionary history of this region has produced heterogeneous landscapes and riverscapes at multiple scales, altered the geographic and genetic connections among populations, and impacted rates of adaptation, speciation, and extinction. In turn, ecologically diverse Amazonian biotas promoted further diversification, species coexistence, and coevolution, with biodiversity accumulating over tens of millions of years. Important events in Amazonian history included: (i) late Cretaceous and early Paleogene origin of major rainforest plant and animal groups; (ii) Eocene-Oligocene global cooling with rainforests contracting to tropical latitudes separating Atlantic coastal and Amazonian rainforests; (iii) Miocene uplift of central and northern Andes that separated Pacific coastal and Amazonian rainforests, spurred formation of mega-wetlands in the western Amazon, and contributed to the origin of the modern transcontinental Amazon River; (iv) late Neogene formation of the Panamanian Isthmus that facilitated the Great American Biotic Interchange; (v) Pleistocene climate oscillations followed by late Pleistocene-Holocene human colonization and megafaunal extinctions; and (vi) modern era of widespread anthropogenic deforestation, defaunation, and ecological transformations of regional landscapes and global climates. Amazonian conservation requires decade-scale investments into biodiversity documentation and monitoring to leverage existing scientific capacity, and strategic habitat planning to allow continuity of evolutionary and ecological processes now and into the future.

Predicting the responses of European grassland communities to climate and land cover change.

European grasslands are among the most species-rich ecosystems on small spatial scales. However, human-induced activities like land use and climate change pose significant threats to this diversity. To explore how climate and land cover change will affect biodiversity and community composition in grassland ecosystems, we conducted joint species distribution models (SDMs) on the extensive vegetation-plot database sPlotOpen to project distributions of 1178 grassland species across Europe under current conditions and three future scenarios. We further compared model accuracy and computational efficiency between joint SDMs (JSDMs) and stacked SDMs, especially for rare species. Our results show that: (i) grassland communities in the mountain ranges are expected to suffer high rates of species loss, while those in western, northern and eastern Europe will experience substantial turnover; (ii) scaling anomalies were observed in the predicted species richness, reflecting regional differences in the dominant drivers of assembly processes; (iii) JSDMs did not outperform stacked SDMs in predictive power but demonstrated superior efficiency in model fitting and predicting; and (iv) incorporating co-occurrence datasets improved the model performance in predicting the distribution of rare species. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

A freshwater ecosystem once existed in the Rajasthan desert: evidence from a fossil of the aquatic herb Nelumbo

Nelumbonaceae encompasses aquatic plant lineages that represent major components in the modern tropical wetland ecosystems of India. The group is characterized by its distinctive reproductive receptacle incorporating in situ fruitlets and vegetative organs that are well-represented in the fossil record. Unusually, though, no Nelumbo reproductive fossils have yet been identified from the Cenozoic of India. Here, we report the first such fossil reproductive organ from the aquatic perennial herb Nelumbo, which was recovered in the lower Eocene Palana Formation at the Gurha lignite mine in Rajasthan, western India. The fossil preserves an aggregate fruit with 28 indehiscent, apocarpous and globose to oblong fruitlets embedded within an accrescent receptacle, and a single small central cavity or apical remains of a stigma in each fruitlet. Comparisons with extant and extinct Nelumbo species support attribution to Nelumbo sp. Our unexpected discovery of a fully aquatic plant in the Rajasthan Basin during the early Eocene indicates that a freshwater ecosystem existed there ca 55 ± 10 million years ago; this contrasts starkly with the arid climatic conditions predominant in Rajasthan today. Raman Patel† [ ramanpatel2142@gmail.com ], Department of Geology, Hemvati Nandan Bahuguna Garhwal University, Srinagar, 246174 Uttarakhand, India Ashif Ali† [ aashifli0011@gmail.com ], Palaeobotany, Palynology, and Plant Evolution Laboratory, Department of Botany, Sidho-Kanho-Birsha University, Ranchi Road, Purulia-723104, India Rajendra Singh Rana [ rajendra.rana1@gmail.com ], Department of Geology, Hemvati Nandan Bahuguna Garhwal University, Srinagar, 246174 Uttarakhand, India Mahasin Ali Khan* [ khan.mahasinali@gmail.com ], Palaeobotany, Palynology, and Plant Evolution Laboratory, Department of Botany, Sidho-Kanho-Birsha University, Ranchi Road, Purulia-723104, India.

Conservation of Sacred Groves of Rajasthan through Folkloric Beliefs

Sacred groves or sacred woods are groves of trees, related to traditional, religious & cultural beliefs & these areas are dedicated to local deities & ancestor spirits. They can be found as a section of a forest. They are excellent illustrations of in-situ conservation. These groves, which are around the nation in villages & cities, plains, and mountain areas, represent a priceless genetic diversity that helps to preserve our environment in many ways. Many extinct species that could have perished otherwise have been saved because of these virgin forest regions. Besides protecting biological diversity, the entire ecosystem aids in water & soil conservation. In the case of Rajasthan, sacred woods can be considered as one of the preservers of priceless ancient religious practices & traditional beliefs. Therefore, sacred forests offer humanity certain crucial ecological functions. In recent times, drastic changes around the globe have also impacted both religious practices and biological integrity. The destruction of the historic heritage has several causes, some of which need to be investigated, including changes in social beliefs, modernity, and the eroding of cultural practices. It becomes important to spread awareness of the management and conservation of various ecosystem services as well as to suggest management and conservation as an alternative strategy for the sustainability of forestry around human settlements.

Persistence and Stochastic Extinction in a Lotka–Volterra Predator–Prey Stochastically Perturbed Model

The classical Lotka–Volterra predator–prey model is globally stable and uniformly persistent. However, in real-life biosystems, the extinction of species due to stochastic effects is possible and may occur if the magnitudes of the stochastic effects are large enough. In this paper, we consider the classical Lotka–Volterra predator–prey model under stochastic perturbations. For this model, using an analytical technique based on the direct Lyapunov method and a development of the ideas of R.Z. Khasminskii, we find the precise sufficient conditions for the stochastic extinction of one and both species and, thus, the precise necessary conditions for the stochastic system’s persistence. The stochastic extinction occurs via a process known as the stabilization by noise of the Khasminskii type. Therefore, in order to establish the sufficient conditions for extinction, we found the conditions for this stabilization. The analytical results are illustrated by numerical simulations.

Recent Advances in Studies of Genomic DNA Methylation and its Involvement in Regulating Drought Stress Response in Crops

As global arid conditions worsen and groundwater resources diminish, drought stress has emerged as a critical impediment to plant growth and development globally, notably causing declines in crop yields and even the extinction of certain cultivated species. Numerous studies on drought resistance have demonstrated that DNA methylation dynamically interacts with plant responses to drought stress by modulating gene expression and developmental processes. However, the precise mechanisms underlying these interactions remain elusive. This article consolidates the latest research on the role of DNA methylation in plant responses to drought stress across various species, focusing on methods of methylation detection, mechanisms of methylation pattern alteration (including DNA de novo methylation, DNA maintenance methylation, and DNA demethylation), and overall responses to drought conditions. While many studies have observed significant shifts in genome-wide or gene promoter methylation levels in drought-stressed plants, the identification of specific genes and pathways involved remains limited. This review aims to furnish a reference for detailed research into plant responses to drought stress through epigenetic approaches, striving to identify drought resistance genes regulated by DNA methylation, specific signaling pathways, and their molecular mechanisms of action.

Evolution, Evil, Co-Creation and the Value of the World

This article builds on and supplements an earlier one in this journal about theodicy. It focuses on species extinctions and on the possible role of humanity as fallible co-creators. Christopher Southgate has suggested that co-creators might shoulder the task of curtailing extinctions. In appraising this view, I distinguish between extinctions resulting from evolution, which humans have limited power to reverse, but which are held to be indispensable for the evolution of complexity, consciousness and self-consciousness, and those caused by humanity itself, which humans should reduce, even if they cannot be halted. Human creativity, however, extends further to the development of skills, trades, the arts and literature. Church Fathers, such as Ambrose, Theodoret and Cosmas Indicopleustes, held that God left the creation incomplete so that humanity could enhance it; certainly, human creativity has introduced agriculture, navigation, technology and culture, adding to the value of the world. Granted belief in creation, this can be understood as co-creation. Granted the value that humanity continues to add to the world, the belief that such creativity flows from the creator’s overall plan emerges as a coherent one.

Regional differences of functional and taxonomic bird diversity in tropical agroforests of Peru

AbstractDiversity and functionality of bird communities in tropical agroforests are shaped by their surrounding landscape, particularly the extent and type of natural forest. However, most evidence comes from tropical rainforest landscapes, whereas the bearing of such trends in other forest types remains understudied. We compared functional and beta diversity of bird communities in 23 cacao agroforests embedded in landscapes of two contrasting Peruvian regions: seasonally‐dry tropical forests and subtropical rainforests from the Andean foothills. Strong climatic seasonality affects both landscapes, but forest vegetation structure and complexity differ. We found higher bird species richness (n = 179 spp) and higher species turnover in the subtropical forest than in the dry forest landscape (n = 64 spp). Only in the dry forest landscape, distance from forest increased dissimilarity driven by species loss, that is, the nestedness component of beta diversity. This points to the importance of conserving dry tropical forests within the broader landscape matrix, with known benefits for pest control and cacao yield. Functional diversity indices were not influenced by forest distance in either landscape, but the proportion of insects in birds' diet decreased by 27% along a 1 km distance gradient from forest in the subtropical forest landscape. In the dry forest landscape, however, it decreased by only 3% across the same distance gradient. Far from forest (≥1 km), forest specialization decreased by ~33% and 20% in the subtropical and dry forest landscapes, respectively. These differences indicate that regionally‐adapted agroforest management is paramount for conserving bird diversity and ecosystem services as pest control. Procuring high‐canopy shade trees and adequate microhabitats for insectivorous species is essential to maintain biocontrol services in the subtropical forest. Conversely, in the dry forest enhancing low‐canopy vegetation with a focus on frugivores and ensuring forest closeness to agroforests may maximize bird diversity and their ecosystem services. A complete version of this article is translated to Spanish in the supplements.

A new species of Eocene soldier beetle, a Malthodes (Coleoptera: Cantharidae: Malthininae) in Baltic amber

ABSTRACT A new species of soldier beetle (Cantharidae) from Eocene Baltic amber, Malthodes maierae sp. nov., is described and illustrated from a male specimen discovered in Russia. The new species differs from the hundreds of known extant and extinct species of Malthodes Kiesenwetter, 1852. The last abdominal segments, which are substantially modified on the male to hold the female during mating, differ considerably in Malthodes species and are very important diagnostic elements for this genus. The exact evolutionary forces driving these manifold modifications are unknown, but they are likely related to sexual selection, mate recognition, antagonistic coevolution, or varying habitats, or a combination of these factors. The Zoobank LSID for this is: urn:lsid:zoobank.org:pub:DC13FC31-BD71-4C3D-9536-B70AF65FB699

Germination niche of co-occurring threatened native and alien species: a case study in Lindernia procumbens and L. dubia

AbstractPlant invasions have a negative impact on biodiversity and lead to species loss. Although studies on traits promoting invasiveness have been largely developed, comparative studies on germination traits of closely related native versus alien invasive species, which also take into account threatened species, are lacking. We analysed the germination requirements of two congeneric Lindernia species inhabiting paddy field in Northern Italy. Germination tests were conducted exposing seeds of both species across a broad range of temperature and conditions (i.e., cold-wet stratification, dark condition, alternate temperature, gibberellic acid). The invasive L. dubia showed higher and faster germination, occurring over a broader range of temperatures compared to the native threatened L. procumbens, along with a lighter non-deep physiological dormancy. These results show a competitive advantage of the alien species already in the early stages of plant regeneration and provide a comprehensive overview of the germination requirements, necessary for the development of future conservation and management plans.

Preventing Loss of Animal Species Under Human-Caused Climate Change

Preventing Loss of Animal Species Under Human-Caused Climate Change

The global pattern of epiphytic liverwort disparity: insights from Frullania

The geographical and ecological patterns of morphological disparity are crucial to understand how species are assembled within communities in the context of the evolutionary history, morphological evolution and ecological interactions. However, with limited exceptions, rather few studies have been conducted on the global pattern of disparity, particularly in early land plants. Here we explored the spatial accumulation of disparity in a morphologically variable and species rich liverwort genus Frullania in order to test the hypothesis of latitude disparity gradient. We compiled a morphological data set consisting of eight continuous traits for 244 currently accepted species, and scored the species distribution into 19 floristic regions worldwide. By reconstructing the morphospace of all defined regions and comparisons, we identified a general Gondwana-Laurasia pattern of disparity in Frullania. This likely results from an increase of ecological opportunities and / or relaxed constraints towards low latitudes. The lowest disparity occurred in arid tropical regions, largely due to a high extinction rate as a consequence of paleoaridification. There was weak correlation between species diversity and disparity at different spatial scales. Furthermore, long-distance dispersal may have partially shaped the present-day distribution of Frullania disparity, given its frequency and the great contribution of widely distributed species to local morphospace. This study not only highlighted the crucial roles of paleoenvironmental changes, ecological opportunities, and efficient dispersal on the global pattern of plant disparity, but also implied its dependence on the ecological and physiological function of traits.

Managing Forests for Biodiversity Conservation and Climate Change Mitigation.

We include biodiversity impacts in forest management decision making by incorporating the countryside species area relationship model into the partial equilibrium model GLOBIOM-Forest. We tested three forest management intensities (low, medium, and high) and limited biodiversity loss via an additional constraint on regional species loss. We analyzed two scenarios for climate change mitigation. RCP1.9, the higher mitigation scenario, has more biodiversity loss than the reference RCP7.0, suggesting a trade-off between climate change mitigation, with increased bioenergy use, and biodiversity conservation in forests. This trade-off can be alleviated with biodiversity-conscious forest management by (1) shifting biomass production destined to bioenergy from forests to energy crops, (2) increasing areas under unmanaged secondary forest, (3) reducing forest management intensity, and (4) reallocating biomass production between and within regions. With these mechanisms, it is possible to reduce potential global biodiversity loss by 10% with minor changes in economic outcomes. The global aggregated reduction in biodiversity impacts does not imply that biodiversity impacts are reduced in each ecoregion. We exemplify how to connect an ecologic and an economic model to identify trade-offs, challenges, and possibilities for improved decisions. We acknowledge the limitations of this approach, especially of measuring and projecting biodiversity loss.

Weaving feathers of intangible and tangible knowledge: Historical records and human‐bird interactions in the Marquesas Islands

AbstractBirds fulfilled an essential role in ancient Polynesian cultures. They were prized for their bones and colourful feathers, fat, and protein; their cultural importance is further highlighted in Polynesian oral histories. This research investigates the dynamics of human‐bird interactions over time in the Marquesas Archipelago as known from archaeology, oral histories, ethnohistorical records, and museum collections. I analyse the range of avian taxa represented across the various datasets and their cultural uses. The results demonstrate that while some species are represented across one or more datasets, understanding the full extent of species’ cultural roles and use requires more than one thread of analysis, particularly for those taxa with limited or no archaeological signature. Two forms of managed resource use emerge from this study. One is tapu (prohibition of use), and the second is the conservative use of birds as a resource such as restricted feather collecting. Red feathers, represented in museum objects and historical accounts, highlight multiple taxa being used for specific adornment types. The combined analyses provide insights into the loss and persistence of species, as well as aspects of Marquesan cultural management.

The rediscovery of a relict unlocks the first global phylogeny of whip spiders (Amblypygi).

Asymmetrical rates of cladogenesis and extinction abound in the Tree of Life, resulting in numerous minute clades that are dwarfed by larger sister groups. Such taxa are commonly regarded as phylogenetic relicts or "living fossils" when they exhibit an ancient first appearance in the fossil record and prolonged external morphological stasis, particularly in comparison to their more diversified sister groups. Due to their special status, various phylogenetic relicts tend to be well-studied and prioritized for conservation. A notable exception to this trend is found within Amblypygi ("whip spiders"), a visually striking order of functionally hexapodous arachnids that are notable for their antenniform first walking leg pair (the eponymous "whips"). Paleoamblypygi, the putative sister group to the remaining Amblypygi, is known from Late Carboniferous and Eocene deposits, but is survived by a single living species, Paracharon caecus Hansen, 1921, that was last collected in 1899. Due to the absence of genomic sequence-grade tissue for this vital taxon, there is no global molecular phylogeny for Amblypygi to date, nor a fossil-calibrated estimation of divergences within the group. Here, we report a previously unknown species of Paleoamblypygi from a cave site in Colombia. Capitalizing upon this discovery, we generated the first molecular phylogeny of Amblypygi, integrating ultraconserved element sequencing with legacy Sanger datasets and including described extant genera. To quantify the impact of sampling Paleoamblypygi on divergence time estimation, we performed in silico experiments with pruning of Paracharon. We demonstrate that the omission of relicts has a significant impact on the accuracy of node dating approaches that outweighs the impact of excluding ingroup fossils, which bears upon the ancestral range reconstruction for the group. Our results underscore the imperative for biodiversity discovery efforts in elucidating the phylogenetic relationships of "dark taxa", and especially phylogenetic relicts in tropical and subtropical habitats. The lack of reciprocal monophyly for Charontidae and Charinidae leads us to subsume them into one family, Charontidae, new synonymy.

Evaluating dynamic tree-species-shifting and height development caused by ungulate browsing in forest regeneration using a process-based modeling approach

Ungulate browsing can prevent the successful regeneration and development of forest-owner-intended and climate-resilient admixed tree species, compromising the future provision of multiple ecosystem services. A reduction of the height increment of palatable tree species caused by ungulate browsing results in a competition shift in favor of less palatable species. While this key process of losing admixed tree species is well understood, forest growth models have not yet captured its full complexity. Therefore, our objectives were to simulate (i) the loss of susceptible tree species from different browsing regimes and its impact on stand development, (ii) changes in the height increment of saplings and trees, and (iii) the shifts in social status during stand development without pre-defined limits a sapling can resist browsing. To address these objectives, we used the process-based model iLand to simulate the exposure of Norway spruce, Silver fir, and European beech stands to varying browsing densities. We successfully reproduced expected dynamic shifts in species composition and height development 24 years after establishment, depending on ungulate pressure and species-specific competitive strength. Stand composition and growth differences already occur with slight changes in ungulate density. When saplings remained in stand structure, independent of the number being browsed, our results led to more individuals with substantially smaller dimensions. We found that dynamic tree species shifting can be simulated realistically by a process-based modeling approach, which can be used to show the strong impact of ungulates on stand development.

Extinction selectivity obscures patterns of trait‐dependent endangerment in Columbiformes

AbstractAimUnderstanding how extinction has occurred in the recent past is crucial to unravel its main drivers as well as to implement effective conservation practices to minimize global biodiversity loss. It has long been hypothesized that extinction risk is not randomly distributed among traits of species. However, the actual traits making species more prone to extinction may have been overlooked because already extinct species are often not considered in comparative analyses of extinction risk. We characterized the drivers of extinction in a cosmopolitan bird clade, including Holocene and contemporary extinctions potentially related to human impacts and provided evidence of an ‘extinction selectivity’ in species traits.LocationGlobal.Time periodAnthropocene.Major taxa studiedColumbiformes clade, pigeons and doves.MethodsWe constructed a new phylogenetic hypothesis of the Columbiformes, a cosmopolitan bird clade consisting of 33 recently extinct and 351 extant species. Then, we integrated data on geography, behaviour and morphology to reveal the drivers of extinction risk. We used phylogenetic generalized least square models to test the effect of geography, behaviour and morphology in the risk of extinction and identified differences in the drivers of extinction when including versus excluding recently extinct species.ResultsOur analysis revealed that Columbiformes endemic to islands with ground‐foraging habits, weak flying abilities, migratory behaviour and larger body sizes are more vulnerable to extinction. Our results also show that excluding recently extinct species identifies extinction drivers different from those when including recently extinct species.Main conclusionsOnly by accurately identifying the traits that increase extinction risk we can develop targeted conservation measures that promote the long‐term persistence of threatened species. Extinction selectivity has important implications for the conservation of biological communities and ultimately ecosystem functioning, considering the critical role Columbiformes often play as seed dispersers.

The Representation of The Ecological Crisis in Indonesian Novels: How Does The Social-Ecological System Occur?

Abstract. While Indonesian novels have been explored for their depiction of ecological crises, there has yet to be a detailed examination of how these narratives reflect the ensuing socio-ecological systems. This study investigates the portrayal of socio-ecological systems within Indonesian novels in the context of ecological crises. Employing qualitative methods and content analysis, this research utilizes the updated socio-ecological systems framework proposed by McGinnis and Ostrom (2014). The findings reveal various aspects of the crises represented, including forest destruction, forest fires, air pollution, animal extinction, and the degradation of natural reserves. Furthermore, the ecological crisis that has occurred actually gives rise to a socio-ecological system that represents the internal relationships among the resource system, government system, resource unit, and actors, and is influenced by external factors such as the social, economic, and political settings, and related ecosystems. Additionally, this representation of the socio-ecological system provides insights into the conditions of the ecological crisis in Indonesia, particularly in palm oil plantations and nature reserves.Keywords: Ecological Crisis, Social-Ecological System, Indonesian Novels, Ecocriticism

Neoliberalism, World-System Position, and Biodiversity Loss

Several studies provide evidence that social, economic, political, and conservation-related factors impact cross-national biodiversity loss. One theoretical argument concerning biodiversity loss that has not been directly assessed involves the relationship between species loss and neoliberalism. Generally, neoliberalism promotes free markets. This has become a dominant philosophy across nations (though the strength of neoliberalism varies cross-nationally) and affects how nations interact with one another as resource users and providers. Given how neoliberal policies work to integrate nations into a single global capitalist economy, we assess neoliberalism’s effects on threatened species alongside a nation’s position in the global world-system. The current study examines nine sets of negative binomial regression models analyzing the effect of neoliberalism, world-system position, and a set of control variables on species biodiversity loss across a sample of 104 countries for which all relevant data were available. We find some support that neoliberalism increases biodiversity loss in fully assessed species (birds and amphibians). We also find support for the hypothesis that there is more biodiversity loss in the periphery and semi-periphery of the world-system (compared with core countries) in fully assessed threatened species. We argue that the results support previous research showing the sociological drivers of biodiversity loss.

Interactive effects of drought and deforestation on multitrophic communities and aquatic ecosystem functions in the Neotropics-a test using tank bromeliads.

Together with the intensification of dry seasons in Neotropical regions, increasing deforestation is expected to exacerbate species extinctions, something that could lead to dramatic shifts in multitrophic communities and ecosystem functions. Recent studies suggest that the effects of habitat loss are greater where precipitation has decreased. Yet, experimental studies of the pure and interactive effects of drought and deforestation at ecosystem level remain scarce. Here, we used rainshelters and transplantation from rainforest to open areas of natural microcosms (the aquatic ecosystem and microbial-faunal food web found within the rainwater-filled leaves of tank bromeliads) to emulate drought and deforestation in a full factorial experimental design. We analysed the pure and interactive effects of our treatments on functional community structure (including microorganisms, detritivore and predatory invertebrates), and on leaf litter decomposition in tank bromeliad ecosystems. Drought or deforestation alone had a moderate impact on biomass at the various trophic level, but did not eliminate species. However, their interaction synergistically reduced the biomass of all invertebrate functional groups and bacteria. Predators were the most impacted trophic group as they were totally eliminated, while detritivore biomass was reduced by about 95%. Fungal biomass was either unaffected or boosted by our treatments. Decomposition was essentially driven by microbial activity, and did not change across treatments involving deforestation and/or drought. Our results suggest that highly resistant microorganisms such as fungi (plus a few detritivores) maintain key ecosystem functions in the face of drought and habitat change. We conclude that habitat destruction compounds the problems of climate change, that the impacts of the two phenomena on food webs are mutually reinforcing, and that the stability of ecosystem functions depends on the resistance of a core group of organisms. Assuming that taking global action is more challenging than taking local-regional actions, policy-makers should be encouraged to implement environmental action plans that will halt habitat destruction, to dampen any detrimental interactive effect with the impacts of global climate change.