Ecology History Research Articles

Land-use change is associated with multi-century loss of elephant ecosystems in Asia

Understanding historic patterns of land use and land cover change across large temporal and spatial scales is critical for developing effective biodiversity conservation management and policy. We quantify the extent and fragmentation of suitable habitat across the continental range of Asian elephants (Elephas maximus) based on present-day occurrence data and land-use variables between 850 and 2015 A.D. We found that following centuries of relative stability, over 64% (3.36 million km2) of suitable elephant habitat across Asia was lost since the year 1700, coincident with colonial-era land-use practices in South Asia and subsequent agricultural intensification in Southeast Asia. Average patch size dropped 83% from approximately 99,000–16,000 km2 and the area occupied by the largest patch decreased 83% from ~ 4 million km2 (45% of area) to 54,000 km2 (~ 7.5% of area). Whereas 100% of the area within 100 km of the current elephant range could have been considered suitable habitat in the year 1700, over half was unsuitable by 2015, driving potential conflict with people. These losses reflect long-term decline of non-forested ecosystems, exceeding estimates of deforestation within this century. Societies must consider ecological histories in addition to proximate threats to develop more just and sustainable land-use and conservation strategies.

Adaptation of Life Form Categorisation of Ellenberg and Mueller-Dombois to the Hungarian Flora

The categorisation of plant species according to their life form has a long history in plant ecology. The most popular system worldwide and also in Hungary is Raunkiaer’s categorisation according to the position of buds (meristems) surviving the adverse season. The original system contains only seven categories, resulting in high diversity within each category. Therefore, different refinements are suggested. This paper aims to apply an internationally accepted refinement of Raunkiaer’s categorisation, the Ellenberg and Mueller-Dombois system, to the Hungarian flora.

The Oriental Cockroach Blatta orientalis L. Recovered from Early Roman London: Implications for Past Distribution and Roman Trade

ABSTRACT This paper describes the recovery and identification of oothecae of the oriental cockroach (Blatta orientalis L.) from deposits associated with an Early Romano-British bakery oven from Roman Londinium (now modern-day London). The ecology, behaviour and past archaeological history of this species are presented. The implications of finding this species for our understanding of the movement and importation of stored products and other materials by the Roman Army and citizenry is outlined.

Zooarchaeological assemblages contextualize the historical ecology and harvest of fur-bearing mammals in Vermont

Shifting baselines can skew species harvest guidelines and lead to potentially inaccurate assessments of population status and range. The North American Fur Trade (~1600–1900 CE) profoundly impacted the continent’s socio-ecological systems, but its legacies are often not incorporated in management discussions. We apply a conservation paleobiology lens to address shifting baselines of nine species of fur-bearing mammals in Vermont, including seven mesocarnivores and two semi-aquatic rodents. Using a database maintained by the Vermont Division for Historic Preservation, we identified 25 existing radiocarbon dates of fur-bearer associated features from 16 archaeological localities spanning the Early-Late Holocene. We also generated 7 new radiocarbon dates on beaver and muskrat bones from the Ewing (VT-CH-005), Bohannon (VT-GI-026), and Chimney Point (VT-AD-329) localities. Our new radiocarbon dates cluster within the Late Holocene, immediately prior to and throughout the European contact period, and overlap with The Beaver Wars. We recover a ~8,000 year record of beaver harvest, affirming the millennial scale importance of beavers, a species that is often the focus of human-wildlife conflict research. Comparison of zooarchaeological occurrences with digitized natural history specimens and community science observations reveals geographic range continuity for most species except for the American marten, which was historically extirpated, and confirms the native status of the red fox. While taphonomic constraints make our dataset a conservative assessment, our case studies demonstrate how wildlife managers can employ zooarchaeological data to better understand long-term properties of coupled socio-ecological systems and highlight the cultural importance of these species to Indigenous trade networks prior to the Fur Trade in Vermont.

Coastal Archaeology and Historical Ecology for a Changing Planet

Our ocean planet is home to diverse marine environments and organisms that played an important role in human evolution and ecology. Today, coastal marine ecosystems are dramatically degraded and threatened by climate change, habitat destruction, overfishing, and more, leaving key questions about the future of ocean ecosystems in increasingly unstable times. Archaeology provides perspectives on past marine ecosystems and people’s role in shaping and influencing coastal environments prior to the dramatic changes of the postindustrial era. Drawing on archaeological research from the California Coast and the Chesapeake Bay, I explore how an understanding of long-term human interactions with marine ecosystems can help address contemporary environmental challenges and better prepare us for an uncertain future. Although clear examples of archaeological research guiding present-day biological conservation management and policy are limited, there are important signs of success. These include collaboration with Indigenous communities; growing recognition by biologists, ecologists, and other scientists of the significance of archaeological and historical ecological perspectives; and continued emphasis on the links between environmental conservation and social justice.

Notes on an interspecific interaction between distant taxa: Observation of active cohabitation and communal nesting resources between Gehyra mutilata (Wiegmann, 1834) and two vespid wasp species

AbstractTropical ecosystems are biodiverse and ecologically complex, supporting nearly half of the global herpetofauna. Ecological interactions play a role in the maintenance of species diversity with a range of ecological interactions occurring within and among species in tropical ecosystems. Incidental observations of ecological interactions provide an important contribution to the understanding of the ecology and natural history of species. Here, we report an interspecific interaction between distant taxa, the Four‐Clawed Gecko (Gehyra mutilata) utilizing an active communal nesting site and shared nesting resources with two vespid wasp species (Eumeninae and Polistinae), where previous observations documented species utilizing abandoned nesting resources. This is the first known record of three species actively cohabitating in a shared nesting resource. This observation, with one or all species positively benefiting from the ecological interaction, likely indicates a mutualistic or commensal ecological interaction. Incidental observations such as the present study are likely to reveal that interspecific ecological interactions including communal nesting are more widespread than previously thought and the co‐utilization of existing nesting resources presents an advantage for taxa. Observations such as these provide the basis for understanding the complex network of ecological interactions occurring in tropical rainforests.

Riparian Invasive Alien Plant Species in Southern Transylvania (Romania): History of Introduction, Chorology and Ecology

Abstract The establishment and spread of invasive alien plant species (IAPS) outside their natural habitats have irreversibly affected native biodiversity in almost every habitat type. For Southern Transylvania, we recognise that there are about 200 adventive plants. From those, we selected 18 IAPS that occupy riparian habitats, the most common, abundant, frequent or with higher impact on habitats and human health. We studied the history of their introduction in the study area, their distribution paths and means of spreading in the wild, their chorology and ecology.

Notes on the distribution, ecology, and life history of Maotoweta virescens (Orthoptera, Rhaphidophoridae, Macropathinae) and a comparison of two survey methods

When described in 2014, Maotoweta virescens was believed to be one of New Zealand’s rarest cave wētā (Rhaphidophoridae). Here, we present new information about the distribution, ecology, and life history of the species. M. virescens has now been recorded from indigenous forest sites throughout the length of the western South Island, where it can occur in relatively high abundance. M. virescens shows a close association with arboreal mosses, particularly Weymouthia mollis, roosting within them during the day and feeding on them at night. The wētā has also been documented feeding on lichens and dead insects. The species is hypothesized to have a lifecycle of approximately one year, closely linked to season. Eggs are thought to hatch out relatively quickly after being laid in summer and early autumn, with the species overwintering as nymphs and maturing the following late spring through to early-autumn. Further work is required to fully understand its biology. A comparison was made between active night searching and vegetation beating as two different methods for the detection and monitoring of M. virescens. Beating of W. mollis and other suitable M. virescens microhabitats was found to be significantly more effective than night searching. Our results show that M. virescens is widespread and can occur at relatively high densities within South Island temperate forests, with the species’ perceived rarity to date largely owing to a lack of survey effort and the past use of ineffective sampling methods.

Determinants of Microbial-Derived Dissolved Organic Matter Diversity in Antarctic Lakes.

Identifying drivers of the molecular composition of dissolved organic matter (DOM) is essential to understand the global carbon cycle, but an unambiguous interpretation of observed patterns is challenging due to the presence of confounding factors that affect the DOM composition. Here, we show, by combining ultrahigh-resolution mass spectrometry and nuclear magnetic resonance spectroscopy, that the DOM molecular composition varies considerably among 43 lakes in East Antarctica that are isolated from terrestrial inputs and human influence. The DOM composition in these lakes is primarily driven by differences in the degree of photodegradation, sulfurization, and pH. Remarkable molecular beta-diversity of DOM was found that rivals the dissimilarity between DOM of rivers and the deep ocean, which was driven by environmental dissimilarity rather than the spatial distance. Our results emphasize that the extensive molecular diversity of DOM can arise even in one of the most pristine and organic matter source-limited environments on Earth, but at the same time the DOM composition is predictable by environmental variables and the lakes' ecological history.

Coloniality and development impact intraclutch consistency of avian eggs: a comparative analysis of theindividual repeatability of eggshell size and shape metrics.

In oviparous animals, egg morphology is considered an aspect of the extended phenotype of the laying mother and, thus, can be directly assessed for consistency both within and between individual females. Despite a recently renewed interest in the evolution and mechanics of avian eggshell morphology, we still lack a large-scale, comparative understanding of which egg traits are individually plastic and whether individual consistency is shaped by ecological and life history traits at the species level. Here, we aimed to understand whether intraclutch repeatability per se of different eggshell metrics is an evolving trait that responds to selection pressures from socio-ecological contexts across a diverse group of avian species for which clutch-level eggshell morphology data were available to us. Coloniality, ontogeny, and incubation period had significant impacts on the comparative patterns of relative individual repeatability among two egg metrics (i.e., size and shape), whereas other life history traits (including adult size, clutch size, nest type, migration, breeding latitude, host status of brood parasitism) did not have statistical impacts. Our results also demonstrate that individual consistency has a more widespread phylogenetic distribution than expected by evolutionary contingency across avian diversity. Future analyses should also incorporate the effects of intra- and interspecific covariation in other morphological and physiological traits on the evolution of individual consistency, especially those relevant to egg recognition, including eggshell color and maculation.

Evolution of the Yangtze River and its biodiversity

Documenting the origins of megadiverse (sub)tropical aquatic ecosystems is an important goal for studies of evolution and ecology. Nonetheless, the geological and ecological establishment of the modern Yangtze River remains poorly understood. Here, we reconstruct the geographic and ecological history of an endemic clade of East Asian fishes based on the mitochondrial phylogenomics analysis of Cyprinidae using 15 fossil calibrations. We estimate an ancestral condition of benthic spawning with demersal or adhesive eggs in southern East Asia before ∼23 Ma and a derived condition of riverine spawning with semibuoyant eggs in the Yangtze by ∼18 Ma. These results imply the formation of Yangtze riverine ecosystems around the Oligocene-Miocene boundary in response to plateau uplift and monsoon strengthening. Some of these cyprinids reverted to benthic spawning with adhesive eggs by ∼15 Ma, a time of rising to peak net diversification rates,indicating the formation of potamo-lacustrine ecosystems by the mid-Miocene during a strong East Asian summer monsoon. Our study provides increased spatiotemporal resolution for the co-evolutionary histories of the Yangtze River and its biodiversity and highlights biological evidence concerning the geomorphological dynamics of the Yangtze River.

Aliphatic hydrocarbons in the lichen class Lecanoromycetes and their potential use as chemotaxonomic indicators and biomarkers

Lichens are found in a wide range of terrestrial habitats and have important roles in terrestrial ecosystems. However, because lichens are easily decomposed and are rarely preserved as fossils, their paleoenvironmental ecology and evolutionary history remain a mystery. We performed lipid analyses on 29 lichen samples belonging to Lecanoromycetes, the largest class of lichens, from several locations in Japan, to determine their potential for use as taxonomic tools and biomarkers. We found that the lichens contained aliphatic hydrocarbons, including n-alkanes, alkenes, and long-chain branched alkanes, fernenes, diploptene, and hop-21-ene. Lichens with a green algal photobiont (photosynthetic symbiotic algae) contained 1,8-heptadecadiene or 6,9-heptadecadiene and 8- and 7-heptadecene, whereas lichens with cyanobacteria as a photobiont did not contain the heptadecadienes but did contain octadecene, nonadecene and nonadecadiene. These differences in characteristics could be attributed to phylogenetic differences in the photobionts that comprised the lichens, indicating that the alkene composition could be used for lichen chemotaxonomy. Although additional research is needed to confirm that this signal gets preserved in sedimentary archives, our results suggest a previously unknown origin for the C17–C19 alkenes in sediments and imply that these components could be used to reconstruct the past composition of lichens.

The effects of ecology and behavior on the evolution of coloration in Coraciiformes

Abstract What drives the evolution of plumage color in birds? Bird color is likely to be under both natural and sexual selection where natural selection may favor evolution toward crypsis or camouflage whereas sexual selection may favor evolution toward conspicuousness. The responses to selection are predicted to relate to species’ ecology, behavior, and life history. Key hypotheses have focused on habitat and light environment, breeding strategy, territoriality, and hunting behavior. We tested these potential causes of color variation in the Coraciiformes, a colorful clade of non-passerine birds, using phylogenetic comparative methods and data on chromatic and achromatic properties of plumage coloration measured from museum specimens. We found that correlates of color evolution in Coraciiformes vary across body regions and depend on the focal color property (chromatic or achromatic properties of plumage coloration). While the light environment showed widespread effects on coloration in multiple body regions for both color properties, selection pressures related to behavioral characteristics had more spatially localized effects (e.g. territoriality on achromatic properties of wing feathers and hunting strategy on chromatic properties of belly feathers). Our results reveal both general patterns that may hold across other bird clades and more nuanced effects of selection that are likely to be mediated through the visual ecology of the signaler and receiver and the behavioral characteristics of Coraciiform species.

The Yale Geochronometric Laboratory and the Rewriting of Global Environmental History.

Beginning in the nineteenth century, scientists speculated that the Pleistocene megafauna-species such as the giant ground sloth, wooly mammoth, and saber-tooth cat-perished because of rapid climate change accompanying the end of the most recent Ice Age. In the 1950s, a small network of ecologists challenged this view in collaboration with archeologists who used the new tool of radiocarbon dating. The Pleistocene overkill hypothesis imagined human hunting, not climate change, to be the primary cause of megafaunal extinction. This article situates the Pleistocene overkill hypothesis in a broader history of the emergence of historical ecology as a distinct sub-discipline of paleoecology. Tracing the work of the Yale Geochronometric Laboratory and an interdisciplinary research network that included Paul Sears, Richard Foster Flint, Edward Deevey, Kathryn Clisby, and Paul S. Martin, it reveals how both the methods and the meaning of studying fossil pollen shifted between the 1910s and 1960s. First used as a tool for fossil fuel extraction, fossil pollen became a means of envisioning climatic history, and ultimately, a means of reimagining global ecological history. First through pollen stratigraphy and then through radiocarbon dating, ecologists reconstructed past biotic communities and rethought the role of humans in these communities. By the 1980s, the discipline of historical ecology would reshape physical environments through the practice of ecological restoration.

Trans-generational immune priming is not mediated by the sex of the parent primed: a meta-analysis of invertebrate data.

Traditionally, only vertebrates were thought capable of acquired immune responses, such as the ability to transfer immunological experience vertically to their offspring (known as trans-generational immune priming, TGIP). Increasing evidence challenges this belief and it is now clear that invertebrates also have the ability to exhibit functionally equivalent TGIP. This has led to a surge in papers exploring invertebrate TGIP, with most focusing on the costs, benefits or factors that affect the evolution of this trait. Whilst many studies have found support for the phenomenon, not all studies do, and there is considerable variation in the strength of positive results. To address this, we conducted a meta-analysis to answer the question: what is the overall effect of TGIP in invertebrates? Then, to understand the specific factors that affect its presence and intensity, we conducted a moderator analysis. Our results corroborate that TGIP occurs in invertebrates (demonstrated by a large, positive effect size). The strength of the positive effect was related to if and how offspring were immune challenged (i.e. whether they were challenged with the same or different insult as their parents or not challenged at all). Interestingly, there was no effect of the ecology or life history of the species or the sex of the parent or the offspring primed, and responses were comparable across different immune elicitors. Our publication bias testing suggests that the literature may suffer from some level of positive-result bias. However, even after accounting for potential bias, our effect size remains positive. Publication bias testing can be influenced by diversity in the data set, which was considerable in our data, even after moderator analysis. It is therefore conceivable that differences among studies could be caused by other moderators that were unable to be included in our meta-analysis. Nonetheless, our results suggest that TGIP does occur in invertebrates, whilst providing some potential avenues to examine the factors that account for variation in effect sizes.

Integrating Historical Ecology and Environmental Justice

Environmental justice studies (EJS) provides a framework for interdisciplinary research and advocacy in the realm of cultural heritage research and management. Ethnobiologists, in particular those who focus on environmental archaeology, are no strangers to the heritage arena as our scholarship commonly concerns “cultural keystone places,” which are rich with meaning for one or more groups of people. Three dimensions and three core concepts of EJS can serve as guideposts to research centering on these significant places. These EJS concepts align and intersect with core principles of historical ecology (HE), particularly through the study of landscapes as complex systems. This paper highlights how environmental justice and HE can be conceptually integrated. This EJS-HE framework is relevant to research design in environmental archaeology and more broadly ethnobiology, a framing to be adopted at the beginning of the research process that explicitly considers whether a research question is ethical to approach within a particular heritage context.

Editorial: Welcome to Wildlife Letters

Editorial: Welcome to <i>Wildlife Letters</i>

Population genomics and phylogeography of four Australasian waterfowl

ABSTRACT Biogeographic barriers can restrict gene flow, but variation in ecological drivers of dispersal influences the effectiveness of these barriers among different species. Detailed information about the genetic connectivity and movement of waterfowl across biogeographic barriers in northern Australia and Papua New Guinea is limited. We compared genetic connectivity for four species of Australasian waterfowl that vary in their capacity and predisposition for dispersal: Radjah Shelduck (Radjah radjah), Wandering Whistling Duck (Dendrocygna arcuata), Green Pygmy Goose (Nettapus pulchellus), and Pacific Black Duck (Anas superciliosa). We obtained >3,700 loci from double-digest restriction-associated DNA sequencing for 15 to 40 individuals per species and found idiosyncratic patterns of population structure among the four species. The mostly sedentary Radjah Shelduck exhibited clear genetic differences between New Guinea and Australia as well as among locations within Australia. Although the population structure was consistent with isolation by distance, the Torres Strait and Carpentaria Barrier contributed more to genetic differences than geographic distance alone. In contrast, the presumed sedentary Green Pygmy Goose did not show obvious structure. Likewise, populations of the more dispersive Wandering Whistling Duck and Pacific Black Duck were unstructured and genetically indistinguishable between southern New Guinea and northern Australia. Our data suggest that some Australo-Papuan biogeographical barriers are insufficient to impede gene flow in waterfowl species capable of dispersing great distances. In sedentary species like the Radjah Shelduck, these barriers, perhaps coupled with its ecology and natural history, restrict gene flow. Our findings bring new insight into the population ecology of Australo-Papuan waterfowl.

Forest ecology and fire history of the mixed conifer forest belt in the Italian Alps from Late Roman fires to the 20th century under cultural and climate pressure

We reconstructed vegetation, fire and watershed history during the Late Roman-Early Middle Ages and in the last three centuries in a mixed conifer forest forming the middle mountain elevational belt in the inner Alpine region, analyzing co-registered micro-botanical data, charcoal particles, sediment lithology, nutrients, and modern pollen deposition from a high-resolution peat record in Valmalenco (Italian Alps). During Late Roman Age the site hosted a dump mixed conifer forest dominated by Picea abies and Abies alba on peaty forest soil, locally affected by fires which also triggered episodes of hillslope denudation. Fire frequency increases during Early Middle Ages dry and warm phases, favoring Alnus viridis and Larix, while Abies alba and Alnus glutinosa type maintained a main role in the pre- and post-fire. Specifically, Abies alba, nowadays eradicated from the Valmalenco watershed, withstood the local regime of low intensity surface fires for more than a millennium, from the Late Roman throughout the Early Middle Ages. Larix, Alnus viridis and Fraxinus excelsior abundance in modern vegetation is ascribed to effects of intensified disturbance in the Early Modern Age, and to further woodland thickening triggered by fire suppression and abandonment after the Second World War.

Epigenetic potential: Promoter CpG content positively covaries with lifespan and is dependent on gene function among vertebrates.

Variation in DNA methylation is associated with many ecological and life history traits, including niche breadth and lifespan. In vertebrates, DNA methylation occurs almost exclusively at "CpG" dinucleotides. Yet, how variation in the CpG content of the genome impacts organismal ecology has been largely overlooked. Here, we explore associations between promoter CpG content, lifespan and niche breadth among 60, amniote vertebrate species. The CpG content of 16 functionally relevant gene promoters was strongly, positively associated with lifespan in mammals and reptiles, but was not related to niche breadth. Possibly, by providing more substrate for CpG methylation to occur, high promoter CpG content extends the time taken for deleterious, age-related errors in CpG methylation patterns to accumulate, thereby extending lifespan. The association between CpG content and lifespan was driven by gene promoters with intermediate CpG enrichment-those known to be predisposed to regulation by methylation. Our findings provide novel support for the idea that high CpG content has been selected for in long-lived species to preserve the capacity for gene expression regulation by CpG methylation. Intriguingly, promoter CpG content was also dependent on gene function in our study; immune genes had on average 20% less CpG sites than metabolic- and stress-related genes.