Period Of Environmental Change Research Articles

A global database of soil seed bank richness, density, and abundance.

A soil seed bank is the collective name for viable seeds that are stored naturally in the soil. At the species or population level, the ability to form a seed bank represents a strategy for (re)colonization following a disturbance or other change in the local environmental conditions. At the community level, seed banks are thought to buffer local diversity during periods of environmental change and are often studied in relation to the potential for passive habitat restoration. The role that seed banks play in plant population and community dynamics, as well as their importance in the agricultural sector, means that they have been widely studied in ecological research. This database is the result of a comprehensive literature search, including all seed bank studies from the Web of Science from which data could be extracted, as well as an additional search of the Russian language literature. The database contains information on the species richness, seed density, and/or seed abundance in 3096 records from at least 1929 locations across the world's seven continents, extracted from 1442 studies published between 1940 and 2020. Records are grouped into five broad habitat categories (aquatic, arable, forest, grassland-including shrubland-and wetland), including information relating to habitat degradation from, or restoration to other habitats (total 14 combinations). Sampling protocols were also extracted for each record, and the database was extensively checked for errors. The location of each record was then used to extract summary climate data and biome classification from external published databases. The database has several potential uses. The large geographical spread relative to many other global biodiversity datasets is relevant for investigating patterns of diversity in biogeographical or macroecological contexts. Habitat type and status (intact, degraded, and restored) can be used to provide insights for biodiversity conservation, while the potential effects of sampling method and effort can be used to inform optimized data collection for future seed bank studies. This database is released under the CC-BY license.

North Atlantic right whale Eubalaena glacialis prey selection in Cape Cod Bay

North Atlantic right whales Eubalaena glacialis have been observed feeding in Cape Cod Bay (CCB) for over 8 decades, making CCB the most consistent known feeding habitat under shifting ocean and climate conditions. Determining the composition of the right whales’ prey resource in a stable feeding habitat during a period of environmental change will inform conservation efforts throughout their habitat range. We compared zooplankton sampled in the paths of skim-feeding right whales to the bay-wide zooplankton resource in CCB over 23 yr. The dominant zooplankton taxa in CCB were Pseudocalanus complex, Calanus finmarchicus, and Centropages spp. during the winter/spring seasons. The succession of these 3 dominant taxa—Centropages spp. to Pseudocalanus complex (day of the year [DOY] mean ± SD: 34 ± 3) to C. finmarchicus (DOY 92 ± 3)—has provided right whales with a stable, multi-month food resource in a small portion of their greater North Atlantic habitat. We found that right whales targeted aggregations of non-dominant prey groups: Pseudocalanus complex and Centropages spp. aggregations when Centropages spp. dominated the bay-wide zooplankton community; Pseudocalanus complex patches and C. finmarchicus patches when Pseudocalanus dominated; and primarily C. finmarchicus copepodite stage CIV and CV aggregations when CIII dominated bay-wide abundances. Over the time series, we found that Centropages spp. abundance increased and C. finmarchicus decreased only at the beginning of the season. CCB remains a critical foraging habitat for right whales due to the phenological cycle of their prey and limited inter-annual changes in prey abundance.

A biotic perspective on the Oligo-Miocene evolution of the Maldives carbonate platform from forward stratigraphic modelling (Indian Ocean)

Forward stratigraphic modelling is a fast-developing modelling approach, used to test conceptual models, and predict stratigraphic architecture and depositional facies from basin to reservoir scales. Published subsurface applications demonstrate its added value by integrating multidisciplinary data as well as geological concepts into its constraints. When applied to carbonate depositional systems, composed of multiple sediment factories, the co-operating and interdependent production mechanisms remain poorly studied. By applying the technique to a well-studied section of the Maldives carbonate platform, a specific model design—adapted to the geological age and setting, and constrained by available data—sheds light on the interaction of its carbonate producers. The results yield a naturalistic depositional facies distribution and offer insight in the changing relationship between biotic communities during the platform evolution. After calibration, the reference model unequivocally links the formerly proposed genetic model to the seismostratigraphic architecture. Furthermore, the results show how environmental changes (seemingly of secondary impact compared to changes in physical accommodation in the stratigraphic record) can induce substantial fluctuations in carbonate production rates of biotic communities, affect the ecological accommodation, and thus impact the platform architecture. Therefore, it is crucial to treat carbonate production rates during periods of environmental change as variables with associated uncertainties in a forward stratigraphic model setup.

Variation in the behaviour of an obligate corallivore is influenced by resource availability

Marine environments are subject to increasing disturbance events, and coral reef ecosystems are particularly vulnerable. During periods of environmental change, organisms respond initially through rapid behavioural modifications. Whilst mean population level modifications to behaviour are well documented, how these shifts vary between individuals, and the relative trade-offs that are induced, are unknown. We test whether the frequency and time invested in different behaviours varies both between and within individuals with varying resource availability. To do this, we quantify differences in four key behavioural categories (aggression, exploration, feeding and sociability) at two sites of different resource availability, using an obligate corallivore butterflyfish species (Chaetodon lunulatus). Individuals on a low resource site held larger territories, investing more time in exploration, which was traded off with less time invested on aggression, feeding and sociability. Repeatability measures indicated that behavioural differences between sites could plausibly be driven by both plasticity of behaviour within individuals and habitat patchiness within feeding territories. By combining population-level means, co-correlation of different behaviours and individual-level analyses, we reveal potential mechanisms behind behavioural variation in C. lunulatus due to differences in resource availability.Significance statementUsing observational methods, we identify differences in the behaviour of an obligate corallivorous butterflyfish (Chaetodon lunulatus) between a high and a low resource site. We use a combination of density surveys, territory mapping and behavioural observation methods in a comparative analysis to relate behaviour directly to the environment in which it occurs. Bringing together insights from game theory and optimal foraging, we also use our results to highlight how understanding the correlations of different behaviours can inform our understanding of the extent to which behaviours are plastic or fixed. Furthermore, by considering how multiple behaviours are correlated, we move away from exploring individual behaviours in isolation and provide an in-depth insight into how differences in behaviour both between individuals and at the population level can affect responses to declining resource availability.

Local melt contamination and global climate impact: Dating the emplacement of Karoo LIP sills into organic-rich shale

The emplacement of Large Igneous Provinces (LIPs) is commonly correlated with global climate change, and environmental and biological crises. To establish this complex causative link, chemical proxies from marine sedimentary sections must be temporally tied to LIP activity through high-precision geochronology. The temporal link is often ambiguous, especially as periods of environmental change are commonly shorter than the full duration of magmatic and volcanic activity in a LIP. Most importantly, temporal relations need to be established through precise and accurate U-Pb geochronology; however, mafic rocks are often undersaturated in zircon or baddeleyite. New U-Pb age determinations of pegmatitic pods from Karoo LIP dolerite sills into the Ecca Group of the Karoo Basin yield single crystal dates with uncertainties below 50 ka, which allow for a new, detailed assessment of this intrusive event. These samples yield complicated age spectra and Hf geochemistry, which indicate that localized assimilation of sedimentary rocks enabled zircon saturation within these mafic melts. Zircon crystallization age interpretations from these data indicate that sill emplacement within the Ecca Group was coeval across the basin within uncertainty of U-Pb dating, and therefore represents a period of particularly high magma flux. Since the Ecca Group is locally exceptionally rich in organic matter, the widespread and rapid sill-related contact metamorphism generated a significant volume of thermogenic volatiles. Given the temporal overlap of the emplacement of sills between 183.147 ± 0.059 Ma and 183.187 ± 0.133 Ma and the timing of the global Toarcian Oceanic Anoxic Event (TOAE), our data support a causal link between this discrete period of high flux emplacement of Karoo sills into the Ecca Group and the global climate change that took place during the Early Jurassic.

Remotely sensed vegetation productivity predicts breeding activity and drought refuges for a threatened bird in semi‐arid Australia

AbstractRefuges play a critical role protecting species against the effects of climate change. Managing high priority refuges could improve species resilience and facilitate dispersal during periods of environmental change. In this study, we identified drought refuges in semi‐arid Australia for a threatened bird, the malleefowl Leipoa ocellata. Using a Poisson regression model, we quantified the effect of remotely sensed vegetation indices, rainfall, soil moisture and site characteristics on malleefowl breeding activity at 144 sites surveyed from 2000 to 2017 during and after drought. We tested the effect of two vegetation productivity indices on malleefowl breeding activity – the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) – averaged across three temporal and three spatial scales during the mound building and incubation stage of the breeding cycle. We found that NDVI and EVI were better predictors of malleefowl breeding activity than soil moisture and winter rainfall. The model with the lowest Akaike information criterion value contained NDVI averaged over 3 months (June–August) and a 1‐km radius. Malleefowl breeding activity had a strong positive association with NDVI (0.42 ± se 0.03) and a negative association with slope (−0.34 ± se 0.03) and vegetation patch size (−0.23 ± se 0.02). We found the proportion of refugia (top 20% of predicted breeding activity) in protected areas was highly variable, decreasing from 42% in an extreme wet year (2011) to 14% in an extreme drought year (2007). Expanding the reserve network to include refugia predicted to occur in the south of semi‐arid Victoria could improve resilience of malleefowl to climate change. We demonstrate how remotely sensed vegetation indices combined with citizen science data can identify where to protect native vegetation with high, stable productivity. Our approach could be applied to a broad range of species in semi‐arid regions vulnerable to climate change.

Problematizing Indigeneity in sub-Saharan Africa: Implications for natural resource management

There is considerable evidence in the literature of the nature of Indigeneity in Africa, yet few studies explore the complexity of definitions of the concept at different spatial scales. This paper builds on existing scholarship by problematizing ‘Indigeneity’ at both regional and national scales through a critical analysis and synthesis of contemporary literature across sub-Saharan Africa, in association with a specific case study from northern Ghana. In generating the review, the concomitant implications for natural resource management and associated conflicts are analyzed. The paper argues that the definitions and conceptualizations of Indigeneity are heterogeneous with numerous ambiguities and complexities at regional and national scales, which have contemporary implications for both acute and prolonged issues of natural resource allocation and management. Claims of Indigeneity in relation to climate change-driven migration and settlement processes are facilitating support for resource access and utilization, but also generating a myriad of problems linked to overlapping and disputed claims. The ambiguity of claims of Indigeneity by vulnerable individuals and groups also has latent implications. Political misunderstandings or conflicts over natural resources are becoming more widespread across Africa during a period of environmental change. Understanding the complexity of Indigeneity at both regional and national scales will provide important opportunities to inform effective policy for the sustainable and equitable distribution and management of resources in sub-Saharan Africa.

Community genomics: a community-wide perspective on within-species genetic diversity.

Community genomics: a community-wide perspective on within-species genetic diversity.

Long‐term resilience in microcrustacean communities despite environmental changes

AbstractThe ability of communities to withstand stress or maintain their species composition over extended periods of environmental changes is a matter of major concern. Here, we utilize a dataset where microcrustacean communities were related to water chemistry in 82 boreal‐alpine lakes over a 50‐yr time span (1968 and 2016), with the same person involved in sampling both times ensuring identical sites and sampling protocols. Over this time span, there has been a 1–2°C increase in mean annual temperatures and prolonged growing seasons. Also, the strong changes in SO4 deposition and acidification, peaking in the early 1980s, followed by a recovery period, have caused not only an increase in pH but also a pronounced browning (elevated DOC) and reduced levels of Ca over the past three decades. Despite this, the microcrustacean diversity and community composition have remained remarkably stable, and this holds both for the species‐rich larger, boreal sites and the species‐poor alpine sites. While likely there are interannual fluctuations in species abundance, and perhaps species may also be missing for certain periods, a combination of local refugia, resting egg seed‐banks and a regional recolonization that may occur at the meta‐population level, aims at maintaining a strong stability in community composition.

Phylogenetic and functional structures of succession in plant communities on mounds of Marmota himalayana in alpine regions on the northeast edge of the Qinghai–Tibet Plateau

Few studies have examined the succession of plant communities in the alpine zone. Studying the succession of plant communities is helpful to understand how species diversity is formed and maintained. In this study, we used species inventories, a molecular phylogeny, and trait data to detect patterns of phylogenetic and functional community structure in successional plant communities growing on the mounds of Himalayan marmots (Marmota himalayana) on the southeast edge of the Qinghai-Tibet Plateau. We found that phylogenetic and functional diversities of plant communities on marmot mounds tended to cluster during the early to medium stages of succession, then trended toward overdispersion from medium to late stages. Alpine species in early and late stages of succession were phylogenetically and functionally overdispersed, suggesting that such communities were assembled mainly through species interactions, especially competition. At the medium and late stages of succession, alpine communities growing on marmot mounds were phylogenetically and functionally clustered, implying that the communities were primarily structured by environmental filtering. During the medium and late stages of succession the phylogenetic and functional structures of plant communities on marmot mounds differed significantly from those on neighboring sites. Our results indicate that environmental filtering and species interactions can change plant community composition at different successional stages. Assembly of plant communities on marmot mounds was promoted by a combination of traits that may provide advantages for survival and adaptation during periods of environmental change.

Facies analysis and environmental interpretation of a late Pleistocene coastal lagoon sedimentary sequence containing a Coprinisphaera-bearing terrestrial episode (Kisimayo, southern Somalia)

For the first time, we here report trace fossils of dung beetle brood balls (Coprinisphaera ichnogenus) in late Pleistocene sediments from Somalia. The sediments containing these traces represent a lagoonal sedimentary sequence, cropping out along some quarry walls in the outskirts of the Kisimayo town. The terrestrial ichnofossils are accompanied by some shells of the giant land snail Achatina, which confirms the subaerial exposure. Indeed, the rock, generally strongly weathered, shows a texture of a foraminiferal packstone-grainstone, rich in bivalve and gastropod molds, of marine origin. The related facies stack is indicative of a period of environmental changes, which took place in a sheltered shallow water coastal area of a tropical carbonate shelf. For a short time, due to a slight lowering in sea-level, this lagoonal area experienced subaerial conditions with accumulation of wave- and wind-driven marine sand in a backshore zone, so allowing the development of environmental conditions suitable for the appearance of terrestrial trace fossils and Achatina. The discovery of Coprinisphaera represents one of the rare African records of the ichnogenus; it is also a unique example for the Indian Ocean’s African coast of a terrestrial episode being found within a lagoonal sequence.

Facing Change through Diversity: Resilience and Diversification of Plant Management Strategies during the Mid to Late Holocene Transition at the Monte Castelo Shellmound, SW Amazonia

Recent advances in the archaeology of lowland South America are furthering our understanding of the Holocene development of plant cultivation and domestication, cultural niche construction, and relationships between environmental changes and cultural strategies of food production. This article offers new data on plant and landscape management and mobility in Southwestern Amazonia during a period of environmental change at the Middle to Late Holocene transition, based on archaeobotanical analysis of the Monte Castelo shellmound, occupied between 6000 and 650 yr BP and located in a modern, seasonally flooded savanna–forest mosaic. Through diachronic comparisons of carbonized plant remains, phytoliths, and starch grains, we construct an ecology of resource use and explore its implications for the long-term history of landscape formation, resource management practices, and mobility. We show how, despite important changes visible in the archaeological record of the shellmound during this period, there persisted an ancient, local, and resilient pattern of plant management which implies a degree of stability in both subsistence and settlement patterns over the last 6000 years. This pattern is characterized by management practices that relied on increasingly diversified, rather than intensive, food production systems. Our findings have important implications in debates regarding the history of settlement permanence, population growth, and carrying capacity in the Amazon basin.

The Origin and Spread of Locally Adaptive Seasonal Camouflage in Snowshoe Hares.

AbstractAdaptation is central to population persistence in the face of environmental change, yet we seldom precisely understand the origin and spread of adaptive variation in natural populations. Snowshoe hares (Lepus americanus) along the Pacific Northwest coast have evolved brown winter camouflage through positive selection on recessive variation at the Agouti pigmentation gene introgressed from black-tailed jackrabbits (Lepus californicus). Here, we combine new and published whole-genome and exome sequences with targeted genotyping of Agouti to investigate the evolutionary history of local seasonal camouflage adaptation in the Pacific Northwest. We find evidence of significantly elevated inbreeding and mutational load in coastal winter-brown hares, consistent with a recent range expansion into temperate coastal environments that incurred indirect fitness costs. The genome-wide distribution of introgression tract lengths supports a pulse of hybridization near the end of the last glacial maximum, which may have facilitated range expansion via introgression of winter-brown camouflage variation. However, signatures of a selective sweep at Agouti indicate a much more recent spread of winter-brown camouflage. Through simulations, we show that the delay between the hybrid origin and subsequent selective sweep of the recessive winter-brown allele can be largely attributed to the limits of natural selection imposed by simple allelic dominance. We argue that while hybridization during periods of environmental change may provide a critical reservoir of adaptive variation at range edges, the probability and pace of local adaptation will strongly depend on population demography and the genetic architecture of introgressed variation.

The Late Quaternary pollen sequence of Toll Cave, a palaeontological site with evidence of human activities in northeastern Spain

Palynological investigations of Toll Cave, a carnivore and archaeological cave site in northeastern Spain, are presented. The inferred vegetation reveals the long-term permanence of mixed pine-oak forests through a long period of environmental changes within the interval MIS 4 to MIS 1, and probably before. A relatively high diversity of woody taxa is found, including conifers, mesophytic angiosperms, Mediterranean forest, and xerothermic scrub. The most outstanding findings include the abundance of Pinus, evergreen Quercus, and Juniperus; the continuous occurrences of deciduous Quercus, Acer, Castanea, Betula, Fraxinus, Buxus, Olea, Salix, and Erica, and the presence of Abies, Taxus, Carpinus betulus, Tilia, Populus, Celtis, Juglans, Ulmus, Calicotome, Cistus, Ephedra fragilis, Myrtus, Pistacia, Rhamnus and Viburnum. Together with the pollen record of the nearby Teixoneres Cave, this new data suggest the existence of woodland refugia during the coldest and most arid stages of the upper Pleistocene across this relatively high-latitude region within the Iberian Peninsula. This study also supports the occurrence of forest ecosystems within the Mediterranean-Eurosiberian ecotone of the Iberian Peninsula in the vicinity of Homo habitats, including Neanderthals.

Temporal Dynamics of the Gut Bacteriome and Mycobiome in the Weanling Pig.

Weaning is a period of environmental changes and stress that results in significant alterations to the piglet gut microbiome and is associated with a predisposition to disease, making potential interventions of interest to the swine industry. In other animals, interactions between the bacteriome and mycobiome can result in altered nutrient absorption and susceptibility to disease, but these interactions remain poorly understood in pigs. Recently, we assessed the colonization dynamics of fungi and bacteria in the gastrointestinal tract of piglets at a single time point post-weaning (day 35) and inferred interactions were found between fungal and bacterial members of the porcine gut ecosystem. In this study, we performed a longitudinal assessment of the fecal bacteriome and mycobiome of piglets from birth through the weaning transition. Piglet feces in this study showed a dramatic shift over time in the bacterial and fungal communities, as well as an increase in network connectivity between the two kingdoms. The piglet fecal bacteriome showed a relatively stable and predictable pattern of development from Bacteroidaceae to Prevotellaceae, as seen in other studies, while the mycobiome demonstrated a loss in diversity over time with a post-weaning population dominated by Saccharomycetaceae. The mycobiome demonstrated a more transient community that is likely driven by factors such as diet or environmental exposure rather than an organized pattern of colonization and succession evidenced by fecal sample taxonomic clustering with nursey feed samples post-weaning. Due to the potential tractability of the community, the mycobiome may be a viable candidate for potential microbial interventions that will alter piglet health and growth during the weaning transition.

Pleistocene-dated biogeographic barriers drove divergence within the Australo-Papuan region in a sex-specific manner: an example in a widespread Australian songbird

Understanding how environmental change has shaped species evolution can inform predictions of how future climate change might continue to do so. Research of widespread biological systems spanning multiple climates that have been subject to environmental change can yield generalizable inferences about the neutral and adaptive processes driving lineage divergence during periods of environmental change. We contribute to the growing body of multi-locus phylogeographic studies investigating the effect of Pleistocene climate change on species evolution by focusing on a widespread Australo-Papuan songbird with several mitochondrial lineages that diverged during the Pleistocene, the grey shrike-thrush (Colluricincla harmonica). We employed multi-locus phylogenetic, population genetic and coalescent analyses to (1) assess whether nuclear genetic diversity suggests a history congruent with that based on phenotypically defined subspecies ranges, mitochondrial clade boundaries and putative biogeographical barriers, (2) estimate genetic diversity within and genetic differentiation and gene flow among regional populations and (3) estimate population divergence times. The five currently recognized subspecies of grey shrike-thrush are genetically differentiated in nuclear and mitochondrial genomes, but connected by low levels of gene flow. Divergences among these populations are concordant with recognized historical biogeographical barriers and date to the Pleistocene. Discordance in the order of population divergence events based on mitochondrial and nuclear genomes suggests a history of sex-biased gene flow and/or mitochondrial introgression at secondary contacts. This study demonstrates that climate change can impact sexes with different dispersal biology in different ways. Incongruence between population and mitochondrial trees calls for a genome-wide investigation into dispersal, mitochondrial introgression and mitonuclear evolution.

Managerial Friction and Land‐Use Policy Punctuations in the Fragmented Metropolis

Despite the portrayal of bureaucratic organizations as resistant to change, public managers have some ability to strategically move land‐use processes out of incrementalism, even when bureaucratic lethargy acts as a drag. This article examines managerial influence in land‐use policy by synthesizing theories of political markets and punctuated equilibrium. An information‐processing logic is developed to explain why local government managers shift from “inward” to “outward” land‐use management strategies in periods of environmental change. "Managerial friction” is defined as a strategic managerial adjustment producing punctuated land‐use policy change in the face of environmental changing conditions. Hypotheses are tested using data on Florida local government comprehensive plan amendments and a Bayesian methodological approach. The evidence suggests managerial friction can be distinguished from the effects of environmental and political complexity as well as other forms of institutional friction, including management turnover, legislative institutions, and bureaucratic structure.

Variations in benthic foraminiferal assemblages in the Tagus mud belt during the last 5700 years: Implications for Tagus River discharge

We analyzed a 10-m sediment core retrieved at 82 m water depth off the coast of the Tagus River (Western Iberian Margin, Portugal) to investigate a linkage between variations in benthic foraminiferal assemblages and Tagus River discharge over the last 5700 years. Benthic foraminiferal assemblages were studied at high resolution in combination with the stable carbon and oxygen isotopic composition of fossil shells of Nonion scaphum, bulk and molecular organic matter properties (TOC, TN, C/N ratio, δ13CTOC, δ15Nbulk, and BIT index), magnetic susceptibility, and XRF analyses. Three periods of environmental changes were identified: 1) high Tagus River discharge in 5750–2200 calendar year before present (cal yr BP), 2) lower discharge characterized by intense upwelling conditions (2250–1250 cal yr BP), and 3) both intense upwelling and Tagus River discharge (1250 cal yr BP-present). The data reveal alternating intense upwelling periods, as shown by the dominance of Cassidulina carinata, Valvulineria bradyana, or Bulimina marginata, whereas periods of increased river discharge are indicated by increase of N. scaphum, Ammonia beccarii, and Planorbulina mediterranensis. The Tagus River discharge was the strongest during the first period, transporting riverine material further offshore and preventing the establishment of a mud belt on the mid-shelf (around 100 m depth). During the second period, a decrease in Tagus River discharge favored the formation of the Tagus mud belt and strongly influenced the benthic environment by creating an organic matter stock. During the third period, intense upwelling and increased Tagus River discharge were recorded by benthic foraminiferal distribution, with an increase of terrestrial elements present in the mud belt. Furthermore, our results showed that variations in benthic foraminiferal assemblages corresponded to the well-known climatic periods in the study area, such as the Roman Period, the Dark Ages, the Medieval Warm Period, and the Little Ice Age. Our study strongly suggests that benthic foraminiferal assemblages can be used as a bio-indicator to trace the influence of past river discharge.

Identifying spatially and temporally transferrable surrogate measures of species richness

We developed a transferable method to identify indicator species and environmental variables that explain considerable variation in species richness. We applied this method to birds and butterflies and conducted novel, rigorous external evaluations of the spatial and temporal transferability of such indicator species. We collected data in the central Great Basin (Lander, Nye, and Eureka Counties, Nevada) and western Great Basin (Mono County, California and Mineral, Douglas, and Lyon Counties, Nevada), United States. We used Bayesian model selection to identify sets of five species that best explained observed variation in species richness of the same or the other taxonomic group in either subregion. We then built random forest models that included only the five identified indicator species and externally tested these models with new data from the other subregion (central or western Great Basin) or a later time in the same subregion. We compared the predictive accuracy of indicator-species only models to that of models based on environmental variables or on both indicator species and environmental variables. In external evaluations, models based on same-taxon indicator species predicted 34–52% of the variation in species richness of birds and 40–70% of the variation in species richness of butterflies. Comparable models based on environmental variables predicted 11–46% of the variation in species richness of birds and 12–67% of the variation in species richness of butterflies. Models based on same-taxon indicator species predicted more variation in species richness than those based on environmental variables in seven of eight cases. Our results suggested that the predictive accuracy and spatial and temporal transferability of models based on indicator species can exceed that of models based on environmental variables. If mechanistic responses to environmental change are consistent through time, tracking the occurrence of a subset of an assemblage during periods of environmental change may allow inference to species richness of the assemblage.

Expansion of the known distribution of Asiatic mouflon (Ovis orientalis) in the Late Pleistocene of the Southern Levant.

Wild sheep (Ovis orientalis) bones recovered from the Natufian site of Shubayqa 1 demonstrate a wider distribution of mouflon in the Late Pleistocene of the Southern Levant than previously known. Early Epipalaeolithic sites are common in the limestone steppe region of eastern Jordan but have yielded only a handful of caprine bones that cannot be identified to species level and few faunal remains from excavated Late Epipalaeolithic sites have been reported. Analysis of animal bone from Shubayqa 1 suggests a significant population of wild sheep could be found concentrated in the basalt desert environment of eastern Jordan during the Late Pleistocene, especially where higher rainfall over the Jebel Druze provided more water. A population of wild sheep was still present in the Pre-Pottery Neolithic A when the nearby site of Shubayqa 6 was occupied. Hunting of diverse, locally available resources including wild sheep at the end of the Pleistocene illustrates the flexible and adaptive exploitation strategies that hunter-forager groups engaged in. This provides further evidence to the increasing body of data showing the creative and opportunistic approach of terminal Pleistocene groups allowing continued occupation even in more marginal environments in a period of environmental change.