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The northern boreal forest treeline is usually considered to be the result of climate limiting tree reproduction. Although climate also influences the cycling of nutrients, the effects of nutrient availability on the treeline have largely been ignored. Various animal activities can alter nutrient cycling, creating microsites of highly fertile soil. Red foxes (Vulpes vulpes) act as ecosystem engineers in the nutrient-poor northern boreal woodlands by concentrating soil nutrients through their denning activities, increasing white spruce (Picea glauca) tree growth. Here, we examined how denning activity affects reproduction in white spruce by determining the number cones per tree, seeds per cone (with or without endosperm, i.e., filled or not) and their viability. Overall, seed production in the study region was low, with an average of 3.7 filled seeds and 0.73 viable seeds per cone. Denning activity affected all stages of seed production, with trees on dens producing an average of two times more cones, three times more total seeds, four times more filled seeds, and 18 times more viable seeds than trees growing away from dens. While cone counts per tree were a good predictor of filled seeds per tree, they were less reliable at predicting viable seeds per tree. Additionally, the number of cones on a tree does not predict the number of filled seeds in a cone, making it difficult for granivores like squirrels and birds to assess food availability from cone abundance. Overall, these results suggest that nutrient availability can play a crucial role in tree reproduction at the treeline and denning activities can create hotspots of seed production and seed viability, acting as a potential food source for granivores and locations for tree reproduction. [ABSTRACT FROM AUTHOR]

Moles—small insectivorous mammals of the family Talpidae—are widespread across the Northern Hemisphere. These subterranean mammals are easily detected through the mounds, or molehills, they construct as surface bioproducts of tunnel systems excavated underground. The dense aggregation of these bioconstructions in a range of environments (e.g., floodplains, woodland, coastal dunes and upland regions) indicates that moles may play an important role in sediment systems. However, compared with other fossorial mammals (e.g., gophers and rabbits), the impact of moles as direct and indirect biogeomorphic agents is poorly understood. Furthermore, little is known about how molehills develop and degrade over time or how long they persist as landscape features. By examining molehills created by the European mole (Talpa europaea) over 4 months on a floodplain in Oxfordshire, UK, we provide a quantitative assessment of how these landforms evolve over time and space. Through the creation of high‐resolution digital elevation models (DEMs) using structure‐from‐motion (SfM) photogrammetry, we derive a variety of metrics describing molehill morphology and produce a detailed record of how molehills change at weekly time intervals. In addition, measurements of molehill volume are used to estimate the excavation rate of moles over a month. Findings show that (i) molehills are dynamic landforms that change in size and shape in response to phases of construction, collapse, erosion and rebuilding; (ii) rates of degradation are influenced by soil characteristics and seasonal weather conditions; (iii) molehills can persist as landscape features for several months; and (iv) moles are capable of moving a substantial volume of sediment in highly active areas (3.89 m3 ha−1 month−1). Future work is now needed to determine the geomorphic impact of T. europaea over larger spatial scales (e.g., river catchments) and longer timescales (e.g., years–decades) to determine its importance in relation to other bioturbators and within the wider sediment system. [ABSTRACT FROM AUTHOR]

Biogenic sedimentary structures offer a unique perspective for understanding the role of the biosphere in the interaction with other Earth subsystems and the building up of our planet. The record of their ancient equivalents provides a wealth of information for reconstructing the role of bioturbators as ecosystem engineers using multiple ichnological proxies and methods. In this study, we present an overview of how bioturbation has worked across a broad range of spatial and temporal scales from the perspective of ecosystem engineering. Comprehensive and systematic datasets allow analyses at regional and global spatial extents, and especially over long temporal scales where sampling intensity and rock record biases can be considered. Our results underscore the significance of the Cambrian Explosion in the establishment of modern‐style shallow marine ecosystems and of the Ordovician Radiation for their deep marine counterparts, as well as the continuous ecosystem impact of bioturbation during Palaeozoic terrestrialization. Comparable datasets for the rest of the Phanerozoic have not yet been compiled. However, preliminary information indicates that colonization of ultra‐deep tiers, the rise to prominence of regenerators, increased burrowing efficiency, and increased compartmentalization of the endobenthic ecospace, were products of the Mesozoic Marine Revolution. The trace‐fossil record offers hard data to evaluate bioturbation as a driving force in ecosystem re‐structuring and as a key factor in geobiological cycles. Models assessing these fundamental issues should be rooted empirically at different scales, from both autoecological and synecological to macroecological, making the best possible use of the rich and rapidly developing ichnological toolbox. [ABSTRACT FROM AUTHOR]

The northern boreal forest treeline is usually considered to be the result of climate limiting tree reproduction. Although climate also influences the cycling of nutrients, the effects of nutrient availability on the treeline have largely been ignored. Various animal activities can alter nutrient cycling, creating microsites of highly fertile soil. Red foxes (Vulpes vulpes) act as ecosystem engineers in the nutrient-poor northern boreal woodlands by concentrating soil nutrients through their denning activities, increasing white spruce (Picea glauca) tree growth. Here, we examined how denning activity affects reproduction in white spruce by determining the number cones per tree, seeds per cone (with or without endosperm, i.e., filled or not) and their viability. Overall, seed production in the study region was low, with an average of 3.7 filled seeds and 0.73 viable seeds per cone. Denning activity affected all stages of seed production, with trees on dens producing an average of two times more cones, three times more total seeds, four times more filled seeds, and 18 times more viable seeds than trees growing away from dens. While cone counts per tree were a good predictor of filled seeds per tree, they were less reliable at predicting viable seeds per tree. Additionally, the number of cones on a tree does not predict the number of filled seeds in a cone, making it difficult for granivores like squirrels and birds to assess food availability from cone abundance. Overall, these results suggest that nutrient availability can play a crucial role in tree reproduction at the treeline and denning activities can create hotspots of seed production and seed viability, acting as a potential food source for granivores and locations for tree reproduction.

Ecosystem engineers are organisms that modify their physical habitats in a way that alters resource availability and the structure of the communities they live in. The evolution of ecosystem engineers over the course of Earth history has thus been suggested to have been a driver of macroevolutionary and macroecological changes that are observed in the fossil record. However, the rise to dominance of ecosystem engineers has not been thoroughly reconstructed. Here, we investigate the history of bioturbation and reef‐building (two of the most important marine ecosystem engineering behaviours today) over the Phanerozoic. Using fossil occurrences from the Paleobiology Database, we reconstruct how common communities influenced by ecosystem engineers were in the oceans, how dominant ecosystem engineers were within their own communities, and the taxonomic and ecological composition of bioturbators and reef‐builders. We find that bioturbation has become an increasingly common ecosystem engineering behaviour over the Phanerozoic, while reef‐building ecosystem engineers have not become more dominant since their Devonian apex. We also identify unique bioturbation and reef‐building regimes that are characterized by different ecosystem engineering taxonomic groups, ecological modes, and dominance, suggesting that the nature of ecosystem engineering has at times rapidly shifted over the course of the Phanerozoic. These reconstructions will serve as important data for understanding how ecosystem engineers have driven changes in biodiversity and ecosystem structure over the course of Earth history. [ABSTRACT FROM AUTHOR]

Ecosystem engineers can radically reshape ecosystems by modulating the availability of resources to other organisms through modifying either physical or biological aspects of the environment. The introduction or removal of ecosystem engineers from otherwise stable ecosystems can impact the diversity of co‐occurring species, such as driving local extinctions of native taxa. While these impacts are well established over ecological timescales for a wealth of taxa, the macroevolutionary implications of the onset of ecosystem engineering behaviours are less clear. Despite this uncertainty, ecosystem engineering has been implicated in several major transitions in Earth history including the appearance of extensive bioturbation during the Cambrian substrate revolution and associated Ediacaran–Cambrian turnover, and the Great Oxygenation Event. Whether ecosystem engineers are frequently associated with turnover and extinction in deep time is not known. Here we investigate this with an eco‐evolutionary simulation framework in which we assign lineages the ability to impact the fitness of co‐occurring taxa through phenotype–environment feedback. We explore numerous conditions, including how frequently such feedback occurs, and whether ecosystem engineers modify or create niches. We show that there is no general expected outcome from the introduction of ecosystem engineers. In a minority of runs, ecosystem engineering lineages completely dominate, rendering all others extinct, but in others they persist (but do not dominate), or die out. We suggest that ecosystem engineers have complex impacts, but possess the capacity to profoundly shape diversity, and it is appropriate to consider them alongside other exogenous extinction drivers in deep time. [ABSTRACT FROM AUTHOR]

Shelter‐building insects are important ecosystem engineers, playing critical roles in structuring arthropod communities. Nonetheless, the influence of leaf shelters and arthropods on plant–associated microbiota remains largely unexplored. Arthropods that visit or inhabit plants can contribute to the leaf microbial community, resulting in significant changes in plant–microbe interactions. By artificially constructing leaf shelters, we provide evidence that shelter‐building insects influence not only the arthropod community structure but also impact the phyllosphere microbiota. Leaf shelters exhibited higher abundance and richness of arthropods, changing the associated arthropod community composition. These shelters also altered the composition and community structure of phyllosphere microbiota, promoting greater richness and diversity of bacteria at the phyllosphere. In leaf shelters, microbial diversity positively correlated with the richness and diversity of herbivores. These findings demonstrate the critical role of leaf shelters in structuring both arthropod and microbial communities through altered microhabitats and species interactions. [ABSTRACT FROM AUTHOR]

Aquaculture is the world's fastest growing food sector and accounts for more than 50% of the world's fish food supply. The significant growth in global aquaculture since the middle of the 20th century has been dubbed by the Blue Revolution. However, it is not the first Blue Revolution to take place in human history. While historically classified as low-ranking, seasonal, or starvation resources in the archaeological discourse, marine foods were vital resources that ancient communities developed and exploited using a vast array of strategies. Among these aquatic strategies was aquaculture. This first Blue Revolution was initiated during the Early Holocene, some 8,000 years ago in China, with archaeologists now documenting aquaculture across the globe. This review considers the commonalities between ancient aquacultural systems including evidence of ecosystem engineering and the development of domesticated landscapes as production systems. People of the past constructed agroecosystems to not only enhance and diversify aquatic resources, but to control the reliability of key subsistence foods and to meet the demands of ritual practice and conspicuous social stratification. These aquaculture systems were maintained for centuries, if not millennia. Worldwide research conducted on ancient aquaculture can provide critical insights into developing more ecologically sustainable, resilient, and diverse marine production systems for coastal communities today, thus, achieving industry sustainability and limiting negative environmental impacts to the world's shorelines and overexploited fisheries. [ABSTRACT FROM AUTHOR]

Conventional oil palm plantations, characterized by monocropping practices, are susceptible to pest infestations due to the lack of diversity in crop composition. This reliance on monoculture often necessitates heavy pesticide use, posing considerable risks to human health, the environment, and biodiversity. In contrast, regenerative agricultural approaches support ecosystem services, such as natural pest control, thereby reducing pesticide dependency and promoting biodiversity while maintaining productivity. The present study examined the composition of arthropod assemblages and understory plant species in chemical-free oil palm plantations, comparing farms with the integration of non-crop plant beds to those without intervention. We established either 10 square plant beds measuring 3 × 3 m or three rectangular beds measuring 9 × 3 m between the planting rows at each experimental plot. Using coloured pan traps and sticky traps, we assessed the relationship between understory plant species richness and arthropod assemblages, including the number of arthropod families, overall abundance, and selected trophic guilds. Our findings reveal that the integration of non-crop plant mixtures significantly enhances the number of arthropod families, as well as the abundance of predatory and phytophagous arthropods. Moreover, we observed that arthropod assemblages, most notably the number of families, overall abundance, abundance of scavengers and predators were significantly and positively correlated with the number of understory vegetation species. The study highlights the potential of establishing non-crop plant bed as a practical approach to enhancing habitat complexity for natural enemies, thereby fostering biodiversity and contribute to the resilience and functioning of agroecosystem within monoculture plantations.

That the activities of organisms influence their surrounding ecological communities, and the environment, has long been appreciated by palaeontologists, as has the role of these activities on both ecological and evolutionary processes. Spillover effects extend the range of ecosystem‐engineering through ecological networks, generating network effects that because of their non‐trophic nature can be challenging to track. Moreover, the cumulative effect of organismal activities can persist far beyond the lifespan of individual organisms, producing ecological inheritances that influence macroecological and macroevolutionary dynamics. This contribution surveys macroevolutionary patterns arising from ecosystem engineering, their potential contribution to evolutionary radiations, and the significance of ecosystem engineering as a public good in the success of evolutionary innovations. Anecdotally, such activities appear to have made important contributions, but considerable work is required for more rigorous understanding. I describe two challenges: the need for palaeontologists to collect abundance data in a way that facilitates comparative study, and the importance of more robust models of ecological (not just trophic) networks involving multigraphs and hypergraphs. [ABSTRACT FROM AUTHOR]

The evolutionary rise of powerful new ecosystem engineering impacts is thought to have played an important role in driving waves of biospheric change across the Ediacaran–Cambrian transition (ECT; c. 574–538 Ma). Among the most heavily cited of these is bioturbation (organism‐driven sediment disturbance) as these activities have been shown to have critical downstream geobiological impacts. In this regard priapulid worms are crucial; trace fossils thought to have been left by priapulan‐grade animals are now recognized as appearing shortly before the base of the Cambrian and represent some of the earliest examples of bed‐penetrative bioturbation. Understanding the ecosystem engineering impacts of priapulids may thus be key to reconstructing drivers of the ECT. However, priapulids are rare in modern benthic ecosystems, and thus comparatively little is known about the behaviours and impacts associated with their burrowing. Here, we present the early results of neoichnological experiments focused on understanding the ecosystem engineering impacts of priapulid worms. We observe for the first time a variety of new burrowing behaviours (including the formation of linked burrow networks and long in‐burrow residence times) hinting at larger ecosystem engineering impacts in this group than previously thought. Finally, we identify means by which these results may contribute to our understanding of tracemakers across the ECT, and the role they may have had in shaping the latest Ediacaran and earliest Cambrian biosphere. [ABSTRACT FROM AUTHOR]

For many evolutionary biologists, fitness differences cause trait frequency changes in populations, and natural selection explains the evolution of adaptations. Treating fitness differences as a cause, however, is more scientific convention rather than decree, and analyses of the causes of natural selection potentially afford richer evolutionary explanations. Unfortunately, the historical assumptions that the complexities of development leave the origins of phenotypic variation unpredictable, and that ecological processes are idiosyncratic, have hindered detailed analysis of the developmental bases of natural selection. A poorly appreciated consequence is that explanations reliant on selection potentially mask particular causal patterns important in evolution. Here, using examples of environmental modification and regulation by organisms ('niche construction', a.k.a. 'ecosystem engineering'), and developmental plastic responses to environmental conditions ('phenotypic plasticity'), I will highlight how the development and activities of organisms create developmental biases that co‐determine the nature of the response to selection, in an often surprisingly well‐regulated manner. Niche construction biases the phenotypic variation exposed to selection, often generating axes of covariation with plastically expressed morphological traits. Taxonomically shared developmental mechanisms aggregate across populations to generate statistical regularities that are easy to miss because the developmental causes of fitness differences are not currently central to the study of evolution. Recent theory and experiments suggest that how organisms develop and what organisms do cause and strengthen the relationship between key traits and fitness, thereby part‐determining the characteristics of natural selection. The findings have implications for understanding parallel evolution, macroevolutionary trends and variation in evolvability. [ABSTRACT FROM AUTHOR]

River channels, riparian and floodplain forms and dynamics are all influenced strongly by biological processes. However, the influence of macroinvertebrates on entrainment and transport of river sediments remains poorly understood. We use an energy‐based approach to explore the capacity of benthic animals to move surficial, gravel‐bed particles in field and laboratory settings and use the results to assess the relative significance of biological and physical benthic processes. Our results showed that in 11 British gravel‐bed rivers, the maximum energy content (i.e., calorific content) of macroinvertebrate communities generally matched the flow energy associated with median discharges and, at multiple sites, exceeded that of the 10‐year return interval flood. A series of laboratory experiments used to estimate the minimum energy expended by signal crayfish (Pacifastacus leniusculus) when performing geomorphic work established that crayfish move gravel particles at energy levels below that expected of the flow, complicating direct comparisons of the capacity for macroinvertebrates and fluvial flows to influence bed mobility. Our findings suggest that the influence of macroinvertebrate communities in either promoting or suppressing, the mobilisation of the bed may be large compared to equivalent values of fluvial energy. Based on these findings, we conclude that in the gravel‐bed rivers studied, the macroinvertebrate community's potential to perform geomorphic work matches or exceeds the stream power during most of the year. Although our study examined biological and fluvial energy systems separately, it is important to recognise that in nature, these systems are highly interactive. It follows that utilising the energy framework presented in this paper could lead to rapid advances in both fluvial biogeomorphology and river management and restoration. [ABSTRACT FROM AUTHOR]

Mangrove forest development critically depends on the establishment and survival of seedlings. Mechanistic insights into how water levels, waves and bed level dynamics influence the establishment process of individual mangrove seedlings are increasing. However, little is known about how spatial and temporal changes in water levels, waves and bed level dynamics across elevation gradients in mangrove forests facilitate/limit seedling dynamics. For this study, a new seedling establishment and growth model was integrated into a process‐based hydrodynamic and morphodynamic numerical model. This biophysical model was applied to a fringing mangrove forest located in the southern Firth of Thames, Aotearoa, New Zealand. This study quantifies the increasing establishment density and survival probability of mangrove seedlings from the lower‐elevated unvegetated intertidal flat toward the higher‐elevated mature mangrove forest. Three cross‐shore zones with distinctive seedling dynamics were identified: (a) a zone with daily tidal inundation where seedling dynamics are episodic and limited by the dispersal of individual propagules that rapidly anchor to the substrate by root growth, (b) a zone with daily to bi‐weekly tidal inundation where seedling dynamics respond to variations in spring‐neap tidal cycles and, (c) a zone with less than bi‐weekly inundation where seedling dynamics are governed by high propagule supply and seedling survival probability. The seedling establishment density and survival probability are dominated by annual extremes in tidal hydroperiod and bed shear stresses, respectively. The obtained parameterizations can be used to incorporate seedling dynamics in decadal‐timescale mangrove forest development models that are instrumental for mangrove management and restoration. Plain Language Summary: The growth of mangrove forests along (sub)tropical coastlines is dependent on the establishment and survival of mangrove seedlings. The seedling establishment process is influenced by tides and waves that occur along these coastlines. Previous studies have considered the conditions under which mangrove seedlings can establish and survive, but little is known about how these conditions vary along coastlines, and how these variations affect seedling establishment and survival near and inside mangrove forests. For this study, a computational model was developed that simulates how tides and waves vary from the sea toward a mangrove forest in Aotearoa New Zealand. The model is extended with the relevant processes for seedling establishment and survival. This study quantifies the density at which mangrove seedlings can establish and what their survival probability is at different bed levels across the forest. It was found that the duration of tidal inundation controls the density at which seedlings can establish, while bed dynamics due to tides and waves limit the survival of the seedlings. These obtained relations are useful for incorporating seedling establishment and survival in long‐term mangrove forest development models that can be used to develop plans for the management and restoration of mangroves. Key Points: Cross‐shore zones in mangrove seedling dynamics are identifiedWave attenuation by mangroves increases seedling survival probability substantially in the forest fringeSeedling establishment density and survival are governed by annual extremes in hydroperiod and wave‐induced bed shear stress [ABSTRACT FROM AUTHOR]

Through unfamiliar and at times marginal environments, successful colonisation of the Pacific Islands relied upon the introduction of domesticated flora and fauna as well as widespread burning to reduce forests and lowland vegetation for agricultural production. These transformations led to the extinction of avifauna, the reduction of forests, and extensive slope erosion and sedimentation into valleys and along shorelines. To date, most attention has been paid to human-induced changes to the terrestrial landscape. In this paper we present the archaeomalacological results from the deeply stratified coastal Kawela Mound, one of the oldest habitation sites in the Hawaiian Islands, with occupation beginning during the 12th century AD. We describe how anthropogenic change of the terrestrial landscape caused sediment run-off, increased shoreline turbidity, and progradation of the adjacent shoreline altering marine habitats, which is recorded in the diversity, size, and habitat preference of food shellfish harvested over nearly eight centuries. The construction of ancient stone-walled fishponds along the littoral shore provided an artificial rocky habitat for shellfish otherwise uncommon along the sandy coast. Consequently, AMS dated layers containing these shellfish provide an indirect avenue for determining the chronology of stone-walled fishponds, the construction of which was directed under the aegis of elites and thus one of the hallmarks of increasing social complexity during the last two centuries before Contact in the late 18th century. [ABSTRACT FROM AUTHOR]

The role of facilitation in shaping natural communities has primarily been studied in the context of plant assemblages, while its relevance for mobile animals remains less understood. Our study investigates whether reciprocal interspecific facilitation may exist between fire ants (Solenopsis richteri) and cavies (Cavia aperea), two mobile animals, in the SW Atlantic coast brackish marshes. Field samples showed a spatial association between ant mounds and cavies, and that ants prefer to use cavy runways for movement within the marsh. Through experiments involving transplanting the dominant plant, cordgrass (Spartina densiflora), and manipulating cavy presence in areas with and without ant mounds, we observed that cavies forage extensively (and defecate more) near ant mounds. The ants actively remove cavy droppings in their mound vicinity. These ant activities and interactions with cavy droppings led to reduced moisture and organic content while increasing nitrate and phosphate levels in marsh sediment. Consequently, this enhanced plant growth, indirectly facilitating the cavies, which preferred consuming vegetation near ant mounds. These cascading indirect effects persisted over time; even four months after cavies left the marshes, transplanted plants near ant mounds remained larger and exhibited more leaf senescence when exposed to cavy herbivory. Therefore, the networks of positive interactions appear to generate simultaneous selection among species (populations), promoting coexistence within the community. Although complex, these reciprocal facilitative effects among mobile animals may be more common than currently believed and should be further studied to gain a better understanding of the underlying mechanisms driving species coexistence in natural communities. [ABSTRACT FROM AUTHOR]

Mangrove trees influence their physical environment by exerting drag on tidal flows and waves while also stabilising the sediment bed of intertidal flats. These processes influence sediment accretion, the mangrove habitat and their resilience to sea level rise. However, little is known about the magnitude and spatial extent of the effects of mangrove forests on sediment transport and the morphology of the intertidal flat. We use manipulated simulations with an extended process‐based numerical model, to study the influence of mangrove forests on intertidal flat morphology on a yearly timescale. The model includes the influence of mangrove trees on tidal flows, waves and sediment dynamics. The model is calibrated and validated with a comprehensive set of measurement data including hydrodynamics, sediment transport and morphological processes from an expanding mangrove forest in the sediment‐rich Firth of Thames estuary in Aotearoa New Zealand. Sediment accretion on the upper intertidal flat is predominantly influenced by the characteristic morphology of the established mangrove forest, with increased bed stability at higher mudflat elevations related to prolonged aerial exposure and drying of the bed. Our results show that, in comparison to the situation without mangroves, sediment accretion increases in the most seaward fringe area of the forest. The unvegetated intertidal flat fronting the mangrove forest captures less sediment compared to the situation without mangroves. The mangrove forest drag triggers the development of a steeper, convex‐up‐shaped, upper intertidal flat profile, especially during periods with higher water levels and waves. These effects are expected to influence the development and storm‐recovery of natural and restored mangrove forests and may contribute to the resilience and persistence of mangrove‐vegetated intertidal flats for coastal flood risk reduction. [ABSTRACT FROM AUTHOR]

The end‐Neoproterozoic transition marked a gradual but permanent shift between distinct configurations of Earth's biosphere. This interval witnessed the demise of the enigmatic Ediacaran Biota, ushering in the structured trophic webs and disparate animal body plans of Phanerozoic ecosystems. However, little consensus exists on the reality, drivers, and macroevolutionary implications of end‐Neoproterozoic extinctions. Here we evaluate potential drivers of late‐Neoproterozoic turnover by addressing recent findings on Ediacaran geochronology, the persistence of classical Ediacaran macrobionts into the Cambrian, and the existence of Ediacaran crown‐group eumetazoans. Despite renewed interest in the possibility of Phanerozoic‐style 'mass extinctions' in the latest Neoproterozoic, our synthesis of the available evidence does not support extinction models based on episodic geochemical triggers, nor does it validate simple ecological interpretations centred on direct competitive displacement. Instead, we argue that the protracted and indirect effects of early bilaterian innovations, including escalations in sediment engineering, predation, and the largely understudied impacts of reef‐building, may best account for the temporal structure and possible selectivity of late‐Neoproterozoic extinctions. We integrate these processes into a generalised model of early eumetazoan‐dominated ecologies, charting the disruption of spatial and temporal isotropy on the Ediacaran benthos as a consequence of diversifying macrofaunal interactions. Given the nature of resource distribution in Ediacaran ecologies, the continuities among Ediacaran and Cambrian faunas, and the convergent origins of ecologically disruptive innovations among bilaterians we suggest that the rise of Phanerozoic‐type biotas may have been unstoppable. [ABSTRACT FROM AUTHOR]

Ants respond fast to changes in soil conditions in agricultural fields, thus they represent a practical, cheap, clean, and accurate tool to diagnose soil fertility before planting a crop. This study assesses the capacity of richness, occurrence, and activity of ant assemblages to indicate soil physicochemical properties in chayote monoculture in Veracruz, Mexico. Sampling was performed in 15 1-ha-plots and was replicated three times before planting chayote from August to October. Ants were collected using pit-fall traps and determined soil properties were texture, density, contents of organic matter (OM), nitrogen (N), and phosphorous (P), pH, and electrical conductivity (EC). In total, 20,385 ant workers belonging to 51 species, 28 genera, 9 tribes and 6 subfamilies were collected. Species richness significantly explained contents of OM, N, and P in a three-weeks sampling. Species occurrence explained clay percentage in the one-week sampling, N, and P contents in the two-weeks sampling and the aforementioned and percentages of sand and silt in the three-weeks sampling. Ant activity predicted more soil properties in the one-week sampling than in those that lasted two and three weeks.Richness, occurrence, and activity of ant assemblages are valuable tools for diagnosing texture, contents of OM, N, and P, and pH of soil before planting chayote monoculture. It contributes to the understanding of the role that ants play in agricultural fields. Therefore, soil management practices should consider indication capacity of ant assemblages to ensure growth and development of morphological structures such roots, stems, leaves, shoots, and fruits of cultivated plants.

The overall trajectory for the human–environment interaction has been punctuated by demographic boom-and-bust cycles, phases of growth/overshooting as well as of expansion/contraction in productivity. Although this pattern has been explained in terms of an interplay between population growth, social upscaling, ecosystem engineering and climate variability, the evoked demographic–resource-complexity mechanisms have not been empirically tested. By integrating proxy data for population sizes, palaeoclimate and internal societal factors into empirical modelling approaches from the population dynamic theory, we evaluated how endogenous (population sizes, warfare and social upscaling) and exogenous (climate) variables module the dynamic in past agrarian societies. We focused on the inland Atacama Desert, where populations developed agriculture activities by engineering arid and semi-arid landscapes during the last 2000 years. Our modelling approach indicates that these populations experienced a boom-and-bust dynamic over the last millennia, which was coupled to structure feedback between population sizes, hydroclimate, social upscaling, warfare and ecosystem engineering. Thus, the human–environment loop appears closely linked with cooperation, competition, limiting resources and the ability of problem-solving. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'. [ABSTRACT FROM AUTHOR]

Stream periphytons are candidate ecosystem engineers in proglacial margins. Here, we quantify the extent to which they are engineers for the case of hillslope‐fed tributaries in the terrace zones of proglacial margin alluvial plains. Candidate ecosystem engineering effects relate to periphyton‐driven changes in (1) vertical infiltration of water, which in turn could aid plant colonization and hence local surface stabilization, and (2) near‐bed hydraulics, notably near‐bed turbulence properties. We ran two flume experiments in parallel in the proglacial margin of the Otemma glacier (Switzerland), reproducing the environmental conditions found in terrace streams. In both experiments, we followed periphyton development on initially bare sediments for 28 days. Then, whilst the experiment continued undisturbed in one flume, in the second and over a further 26 days, we introduced disturbances in the form of desiccation events. Throughout the entire experiment length, we collected imagery for close‐range SfM‐MVS photogrammetry, data on vertical infiltration, and near‐bed hydraulics. The experiments showed that periphyton development significantly changed the streambed properties. First, periphyton development over the timescale of a few days reduced bed roughness and clogged the benthic interstitial space, reducing water infiltration. These effects were insensitive to the disturbance regime. Second, the changes in streambed roughness modified the near‐bed turbulent structures, and this resulted in a reduction of bursting events and in the modification of the turbulent kinetic energy at the near‐bed layer. The latter, however, appeared to be less important in these environments as compared with the impacts on infiltration. Given the low water retaining capacity of glacial sediments, the observation that periphyton can reduce vertical infiltration explains wider observations of their importance in glacial floodplains where vegetation succession is critically constrained by water availability. The relatively reduced impacts on near‐bed turbulence also contribute to explaining why disturbance in proglacial margin streams remains a key limit on ecological succession. [ABSTRACT FROM AUTHOR]

Following various assignments to Archaeocyatha, worm tubes, and finally incertae sedis, the enigmatic Ediacaran–Cambrian taxon Archaeichnium haughtoni has in recent years come to represent somewhat of a wastebasket taxon to which the indeterminate tapering tubular forms common across this interval are assigned. This 'catch‐all' status has been aided in part by both suboptimal specimen photography and the temporary loss of the holotype after its second redescription in 1978. Recent rediscovery of the A. haughtoni holotype in the collections of the Iziko South African Museum in Cape Town has enabled a much‐needed re‐assessment of this critical and cryptic taxon, with results suggesting that this material from the latest Ediacaran or earliest Cambrian of Namibia is among the earliest fossil record examples of marine worm burrow linings, and the oldest examples of linings robust enough to withstand exhumation and current transport. These traces indicate the emergence of this important animalian ecosystem engineering behaviour closer to the Ediacaran–Cambrian boundary than previously thought. [ABSTRACT FROM AUTHOR]

Organisms construct their own environments and phenotypes through the adaptive processes of habitat choice, habitat construction, and phenotypic plasticity. We examine how these processes affect the dynamics of mean fitness change through the environmental change term of the Price Equation. This tends to be ignored in evolutionary theory, owing to the emphasis on the first term describing the effect of natural selection on mean fitness (the additive genetic variance for fitness of Fisher's Fundamental Theorem). Using population genetic models and the Price Equation, we show how adaptive niche constructing traits favorably alter the distribution of environments that organisms encounter and thereby increase population mean fitness. Because niche‐constructing traits increase the frequency of higher‐fitness environments, selection favors their evolution. Furthermore, their alteration of the actual or experienced environmental distribution creates selective feedback between niche constructing traits and other traits, especially those with genotype‐by‐environment interaction for fitness. By altering the distribution of experienced environments, niche constructing traits can increase the additive genetic variance for such traits. This effect accelerates the process of overall adaption to the niche‐constructed environmental distribution and can contribute to the rapid refinement of alternative phenotypic adaptations to different environments. Our findings suggest that evolutionary biologists revisit and reevaluate the environmental term of the Price Equation: owing to adaptive niche construction, it contributes directly to positive change in mean fitness; its magnitude can be comparable to that of natural selection; and, when there is fitness G × E, it increases the additive genetic variance for fitness, the much‐celebrated first term. [ABSTRACT FROM AUTHOR]

Bioturbation, the disturbance of soil and litter by digging animals plays an important role for a variety of species and ecological processes in many ecosystems. The majority of studies globally on the ecosystem engineering effects of digging vertebrates have focussed on mammals, with birds, reptiles and amphibians remaining comparatively understudied. The loss of ecosystem engineers is a key conservation challenge, and the return of these species is increasingly seen as a priority for habitat restoration; yet this concept is highly novel when we consider urban ecosystems. The Australian brush‐turkey (Alectura lathami), historically a rainforest bird and now common in urban ecosystems, displaces significant quantities of soil and leaf litter through its foraging and nest‐building behaviour and has previously been described as an ecosystem engineer. Here, we tested the effect of brush‐turkey nest building on the decomposition rate of leaf litter, an important ecosystem process. We placed mesh bags of dried Angophora costata and Lantana camara leaves at increasing distances from brush‐turkey incubation mounds. We predicted that leaf litter closer to the nest would break down faster during the brush‐turkey breeding season due to increased turnover associated with nest mound maintenance. We found slower leaf litter decomposition in the breeding than the non‐breeding season, but a relatively greater rate of decomposition closer to the mound in the breeding season. Our results show a seasonal difference in the spatial pattern of leaf litter decomposition and movement; we interpret that brush‐turkey mound‐building behaviour was the key driver. The ecosystem services provided by brush‐turkeys are of particular interest for future research as this species is naturally recolonizing areas where it has been absent for decades, including urban areas. The effect of this species on ecosystem processes including nutrient cycling, seedbank stimulation and reduced fuel loads warrants further investigation. [ABSTRACT FROM AUTHOR]

Australian waterscapes were fashioned to meet human needs during the ancient Aboriginal past through the construction of weirs, fish traps and small dams and accompanying socio-cultural practices and institutions. Exemplary amongst Australian water cultures was that of the Gunditjmara of western Victoria, who for thousands of years practiced a sophisticated form of swamp engineering and eel farming in the volcanic landscapes of Budj Bim. Within 150 years of European colonisation, frontier violence, dispossession and hydrological alteration had put an end to the most extensive and oldest aquaculture system in the world. Recent land and water restitution measures enacted in collaborative partnerships with the wider watershed community have enabled the Gunditjmara to restore the Budj Bim wetlands and rebuild their nation. This process entails re-storying engineering and eeling: cultural practices and connections are being retold to gain recognition for the capacity to negotiate change and adapt to geological, climatological and imperial forces. Critical theory and concepts relating to waterscapes, hydro-social relations and the Anthropocene assist in interpreting the resilient efforts of a rural community to retrieve its history and find new ways to care for the past as well as the future. [ABSTRACT FROM AUTHOR]

Shelter building caterpillars act as ecosystem engineers by creating and maintaining leaf shelters, which are then colonized by other arthropods. Foliage quality has been shown to influence initial colonization by shelter-building caterpillars. However, the effects of plant quality on the interactions between ecosystem engineers and their communities have yet to be studied at the whole plant level. We examined how leaf tying caterpillars, as ecosystem engineers, impact arthropod communities on Quercus alba (white oak), and the modifying effect of foliage quality on these interactions. We removed all leaf tying caterpillars and leaf ties on 35 Q. alba saplings during the season when leaf tying caterpillars were active (June–September), and compared these leaf tie removal trees to 35 control trees whose leaf ties were left intact. Removal of these ecosystem engineers had no impact on overall arthropod species richness, but reduced species diversity, and overall arthropod abundance and that of most guilds, and changed the structure of the arthropod community as the season progressed. There was an increase in plant-level species richness with increasing number of leaf ties, consistent with Habitat Diversity Hypothesis. In turn, total arthropod density, and that of both leaf tying caterpillars and free-feeding caterpillars were affected by foliar tannin and nitrogen concentrations, and leaf water content. The engineering effect was greatest on low quality plants, consistent with the Stress-Gradient Hypothesis. Our results demonstrate that interactions between ecosystem engineering and plant quality together determine community structure of arthropods on Q. alba in Missouri. [ABSTRACT FROM AUTHOR]

Predators are widely recognized for their irreplaceable roles in influencing the abundance and traits of lower trophic levels. Predators also have irreplaceable roles in shaping community interactions and ecological processes via highly localized pathways (i.e. effects with well‐defined and measurable spatio–temporal boundaries), irrespective of their influence on prey density or behavior. We synthesized empirical and theoretical research describing how predators – particularly medium‐ and large‐sized carnivores – have indirect ecological effects confined to discrete landscape patches, processes we have termed 'patchy indirect effects (PIEs) of predation'. Predators generate PIEs via three main localized pathways: generating and distributing prey carcasses, creating ecological hotspots by concentrating nutrients derived from prey, and killing ecosystem engineers that create patches. In each pathway, the indirect effects are limited to discrete areas with measurable spatial and temporal boundaries (i.e. patches). Our synthesis reveals the diverse and complex ways that predators indirectly affect other species via patches, ranging from mediating scavenger interactions to influencing parasite/disease transmission risk, and from altering ecosystem biogeochemistry to facilitating local biodiversity. We provide basic guidelines on how these effects can be quantified at the patch and landscape scales, and discuss how predator‐mediated patches ultimately contribute to landscape heterogeneity and ecosystem functioning. Whereas density‐ and trait‐mediated indirect effects of predation generally occur through population‐scale changes, PIEs of predation occur through individual‐ and patch‐level pathways. Our synthesis provides a more holistic view of the functional role of predation in ecosystems by addressing how predators create patchy landscapes via localized pathways, in addition to influencing the abundance and behavior of lower trophic levels. [ABSTRACT FROM AUTHOR]

Ecosystem engineers modify habitats in ways that facilitate other community members by ameliorating harsh conditions. The strength of such facilitation is predicted to be influenced by both beneficiary traits and abiotic context. One key trait of animals that could control the strength of facilitation is beneficiary body size because it should determine how beneficiaries fit within and exploit stress ameliorating habitat modifications. However, few studies have measured how beneficiary body size relates to facilitation strength along environmental gradients.We examined how the strength of facilitation by net‐spinning caddisflies on invertebrate communities in streams varied along an elevation gradient and based on traits of the invertebrate beneficiaries. We measured whether use of silk retreats as habitat concentrated invertebrate density and biomass compared to surrounding rock surface habitat and whether the use of retreat habitat varied across body sizes of community members along the gradient.We found that retreats substantially concentrated the densities of a diversity of taxa including eight different Orders, and this effect was greatest at high elevations. Caddisfly retreats also concentrated invertebrate biomass more as elevation increased. Body size of invertebrates inhabiting retreats was lower than that of surrounding rock habitats at low elevation sites, however, body size between retreats and rocks converged at higher elevation sites. Additionally, the body size of invertebrates found in retreats varied within and across taxa. Specifically, caddisfly retreats functioned as a potential nursery for taxa with large maximal body sizes. However, the patterns of this taxon‐specific nursery effect were not influenced by elevation unlike the patterns observed based on community‐level body size.Collectively, our results indicate that invertebrates use retreats in earlier life stages or when they are smaller in body size independent of life stage. Furthermore, our analysis suggests that facilitation strength intensifies as elevation increases within stream invertebrate communities.Further consideration of how trait variation and environmental gradients interact to determine the strength and direction of biotic interactions will be important as species ranges and environmental conditions continue to shift. [ABSTRACT FROM AUTHOR]

Complexity theory predicts that self‐organized, regularly patterned ecosystems store more biomass and are more resilient than spatially uniform systems. Self‐organized ecosystems are well‐known from the terrestrial realm, with "tiger bushes" being the archetypical example and mussel beds and tropical coral reefs the marine examples. We here identify regular spatial patterns in cold‐water coral reefs (nicknamed "tiger reefs") from video transects and argue that these are likely the result of self‐organization. We used variograms and Lomb–Scargle analysis of seven annotated video transects to analyze spatial patterns in live coral and dead coral (i.e., skeletal remains) cover at the Logachev coral mound province (NE Atlantic Ocean) and found regular spatial patterns with length scales between 62 and 523 m in live and dead coral distribution along these transects that point to self‐organization of cold‐water coral reefs. Self‐organization theory shows that self‐organized ecosystems can withstand large environmental changes by adjusting their spatial configuration. We found indications that cold‐water corals can similarly adjust their spatial configuration, possibly providing resilience in the face of climate change. Dead coral framework remains in the environment for extended periods of time, providing a template for spatial patterns that facilitates live coral recovery. The notion of regular spatial patterns in cold‐water coral reefs is interesting for cold‐water coral restoration, as transplantation will be more successful when it follows the patterns that are naturally present. This finding also underlines that anthropogenic effects such as ocean acidification and bottom trawling that destroy the dead coral template undermine cold‐water coral resilience. Differences in the pattern periodicities of live and dead coral cover further present an interesting new angle to investigate past and present environmental conditions in cold‐water coral reefs. [ABSTRACT FROM AUTHOR]

Classic ecological theory explains species coexistence in variable environments. While spatial variation is often treated as an intrinsic feature of a landscape, it may be shaped and even generated by the resident community. All species modify their local environment to some extent, driving changes that can feed back to affect the composition and coexistence of the community, potentially over timescales very different from population dynamics. We introduce a simple nested modeling framework for community dynamics in heterogeneous environments, including the possible evolution of heterogeneity over time due to community-environment feedbacks. We use this model to derive analytical conditions for species coexistence in environments where heterogeneity is either fixed or shaped by feedbacks. Among other results, our approach reveals how dispersal and environmental specialization interact to shape realized patterns of habitat association and demonstrates that environmental feedbacks can tune landscape conditions to allow the stable coexistence of any number of species. Our flexible modeling framework helps explain feedback dynamics that arise in a wide range of ecosystems and offers a generic platform for exploring the interplay between species and landscape diversity. [ABSTRACT FROM AUTHOR]

Subterranean rodents can act as ecosystem engineers by shaping the landscape due to soil perturbation and herbivory. At the same time, their burrow density is affected by environmental conditions, vegetation and anthropogenic factors. Disentangling this complex interplay between subterranean rodents and their environment remains challenging. In our study, we analysed the interplay of abiotic conditions, vegetation patterns and human land-use and the burrow density of the giant root-rat (GRR; Tachyoryctes macrocephalus), a subterranean rodent endemic to the Afroalpine ecosystem of the Bale Mountains in south-east Ethiopia. Specifically, we examined the effects of GRR on plant species richness and vegetation cover and vice-versa, and how these reciprocal effects might be modulated by temperature, habitat wetness and grazing. Our results showed that increasing GRR burrow density led to decreased vegetation cover, and that effects of GRR on vegetation cover were slightly stronger than vice-versa. Considering the reciprocal causation models, we found that increasing plant species richness led to increased GRR burrow density, while GRR burrow density decreased as vegetation cover increased. Increases in habitat wetness and livestock grazing intensity also directly led to increased GRR burrow density. Our results stress the importance of subterranean ecosystem engineers on vegetation and highlight the vulnerability of these complex interactions to human activity.

Abstract Complexity theory predicts that self‐organized, regularly patterned ecosystems store more biomass and are more resilient than spatially uniform systems. Self‐organized ecosystems are well‐known from the terrestrial realm, with “tiger bushes” being the archetypical example and mussel beds and tropical coral reefs the marine examples. We here identify regular spatial patterns in cold‐water coral reefs (nicknamed “tiger reefs”) from video transects and argue that these are likely the result of self‐organization. We used variograms and Lomb–Scargle analysis of seven annotated video transects to analyze spatial patterns in live coral and dead coral (i.e., skeletal remains) cover at the Logachev coral mound province (NE Atlantic Ocean) and found regular spatial patterns with length scales between 62 and 523 m in live and dead coral distribution along these transects that point to self‐organization of cold‐water coral reefs. Self‐organization theory shows that self‐organized ecosystems can withstand large environmental changes by adjusting their spatial configuration. We found indications that cold‐water corals can similarly adjust their spatial configuration, possibly providing resilience in the face of climate change. Dead coral framework remains in the environment for extended periods of time, providing a template for spatial patterns that facilitates live coral recovery. The notion of regular spatial patterns in cold‐water coral reefs is interesting for cold‐water coral restoration, as transplantation will be more successful when it follows the patterns that are naturally present. This finding also underlines that anthropogenic effects such as ocean acidification and bottom trawling that destroy the dead coral template undermine cold‐water coral resilience. Differences in the pattern periodicities of live and dead coral cover further present an interesting new angle to investigate past and present environmental conditions in cold‐water coral reefs.

Rhodoliths are non-geniculate, free-living coralline red algae that can accumulate on the seafloor and form structurally complex benthic habitats supporting diverse communities known as rhodolith beds. We combined in situ rhodolith collections and imagery to quantify variability, over 9 months and at two sites, in the structural complexity and biodiversity of a subarctic Lithothamnion glaciale rhodolith bed. We show that the unconsolidated rhodolith framework is spatially heterogeneous, yet provides a temporally stable habitat to an abundant and highly diverse macrofauna encompassing 108 taxa dominated by brittle stars, chitons, bivalves, gastropods, polychaetes, sea urchins, and sea stars. Specific habitat components, including large bivalve shells, affect rhodolith morphology and resident macrofauna, with increasingly large, non-nucleated rhodoliths hosting higher macrofaunal density, biomass, and diversity than increasingly large, shell-nucleated rhodoliths. The present study's fine taxonomic resolution results strongly support the notion that rhodolith beds are biodiversity hotspots. Their spatial and temporal domains provide clear quantitative evidence that rhodolith beds provide a stable framework under the main influence of biological forcing until sporadic and unusually intense physical forcing reworks it. Our findings suggest that shallow (<20 m depth) rhodolith beds are vulnerable to ongoing and predicted increases in the frequency and severity of wave storms. [ABSTRACT FROM AUTHOR]

Vegetated coastal ecosystems such as salt marshes, dunes and seagrass meadows occur at the land–sea interface—a dynamic environment typified by harsh growing conditions. These ecosystems are known as biogeomorphic landscapes because their functioning depends on biophysical interactions by which organisms engineer landforms to their own benefit. The strength of such biogeomorphic feedbacks depends on plant traits, such as stem flexibility and shoot density.Recent work demonstrated that dune grasses with similar morphological traits can build contrasting landscapes due to differences in their spatial shoot organization. However, in contrast to dune grasses that trap and stabilize sand particles in aeolian landscapes, flow attenuation in aquatic environments can generate scouring around plant stems and cause uprooting, leading to establishment thresholds for young plants.Yet, it remains unknown how findings from aeolian landscapes translate to aquatic systems and how young clonally expanding plants in hydrodynamically exposed conditions overcome these establishment thresholds by optimizing shoot placement.Here, we measured shoot patterns of 90 establishing cordgrass patches Spartina anglica at 18 European field sites that cover a broad range of hydrodynamic conditions. Next, we carried out a field experiment to investigate how observed spatial shoot patterns affect plant–sediment feedbacks.Surprisingly, field survey analyses reveal highly consistent clustered shoot patterns, regardless of environmental conditions. Experimental results demonstrate that this clustered pattern minimizes scouring compared to densely clumped organizations typically observed in established patches.Synthesis. In contrast to earlier findings highlighting that establishing dune grasses optimize their landscape engineering capacity via a flexible shoot placement strategy, we find that cordgrass instead follows a fixed strategy that minimizes engineering effects in its early life stages. We suggest that marsh grasses avoid physical stress and associated establishment thresholds in their early life stage, and switch to an ecosystem engineering strategy once established. These findings shed new light on how plant traits interact with their environment to shape the landscape and pave the way for improved restoration designs by mimicking the natural shoot organization of establishing vegetation. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Context: Successful conservation requires a detailed understanding of critical habitats required to support different plant and animal populations. This is particularly important for rewilding programs where locally extinct species are often introduced into novel or reintroduced into areas that have been dramatically altered since they were extirpated. Objectives: Here, we explored changes in the volume of foraging pits of three engineers under different vegetation patch types and different landforms in an arid woodland in Australia based on field experiment. Methods: In this study, we examined the foraging habitat of three ecosystem engineers in the arid eastern Australia: a reintroduced mammal, the greater Bilby (Macrotis lagotis), the Small-beaked echidna (Tachyglossus aculeatus) and a varanid, Gould's sand goanna (Varanus gouldii). The soil disturbing activities of these three animals has been shown to lead to marked and persistent changes in a range of critical ecosystem functions and services. We tracked the density, size and habitat location of 4102 foraging pits over 3 years, as the measure of habitat favourability and the time taken for these foraging pits to infill (pit longevity). Results: We found that foraging was non-random, and animals tended to forage more within shrub patches when accounting for the relative cover of shrubs. There were also some differences among different habitat patch types, with generally larger echidna foraging pits beneath shrubs and trees than in the open interspaces. Pit longevity also varied among animal and patch types, with no differences for bilby or goanna pits across all patches, but greater longevity of echidna foraging pits beneath shrubs. Larger pits tended to persist for longer, and those beneath trees were closer together. Conclusion: Our work shows that foraging, and therefore the ecological effects of these animals vary with the target engineer and the biophysical features of the rewilded habitat. Land restoration programs that aim to restore degraded habitat and ecosystem functions must be cognisant of the idiosyncratic effects of different reintroduced engineers, and the makeup of different patch elements within the target restoration area. [ABSTRACT FROM AUTHOR]

Biotic interactions (e.g., predation, competition, commensalism) where organisms directly or indirectly influenced one another are of great interest to those studying the history of life but have been difficult to ascertain from fossils. Considering the usual caveats about the temporal resolution of paleontological data, traces and trace fossils in the sedimentary record can record co-occurrences of organisms or their behaviours with relatively high spatial fidelity in a location. Neoichnological studies and studies on recently buried traces, where direct trophic links or other connections between tracemakers are well-known, may help interpret when and where overlapping traces represented true biotic interactions. Examples from Holocene paleosols and other buried continental sediments in Poland include the tight association between mole and earthworm burrows, forming an ichnofabric representing a predator–prey relationship, and that of intersecting insect and root traces demonstrating the impact of trees as both ecosystem engineers and the basis for food chains. Trampling by ungulates, which leaves hoofprints and other sedimentary disturbances, may result in amensal or commensal effects on some biota in the short term and create heterogeneity that later trace-making organisms, such as invertebrate burrowers, can also respond to in turn, though such modified or composite traces may be challenging to interpret. [ABSTRACT FROM AUTHOR]

Mound-forming ants are important ecosystem engineers as they increase habitat heterogeneity, thus supporting multiple biotic interactions. How these ant-mediated changes in abiotic factors translate into temporal biotic heterogeneity, is a less studied subject. In a case study localized on a Danish heath, we investigated how ant mounds (mineral and organic mounds) affected the phenology and flowering success of five plant species growing on or between ant mounds (Lasius flavus and Formica exsecta). Specifically, we focused on the phenophases' stem elongation, flowering and seed set. All plant species showed significantly earlier phenophases on the mounds compared to control patches between mounds. These advances resulted in two distinct flowering seasons for one plant species and prolonged continuous flowering seasons for the four other species, when mound and non-mound plant seasons were combined. Likewise, stem elongation and seed set seasons were prolonged, with either two distinct seasons or one continuous season, depending on plant species. Two plant species exhibited increased survival up to the flowering stage when growing on ant mounds, since they flowered before a drought killed a large part of the population. Probable drivers behind these effects, as revealed by a structural equation model, were elevated surface temperature and other soil edaphic factors responsible for plant growth. Furthermore, the direct effects of the ant mounds were nearly twice as high for the organic mounds of F. exsecta compared with the mineral mounds of L. flavus. Possible implications are more resilient ecosystems, as prolonged seasons can mitigate phenological mismatches between interacting species. [ABSTRACT FROM AUTHOR]

Wild boar is among the most abundant ungulates in Europe and its spread is locally creating concerns as a major threat to biodiversity. However, through their rooting activity, wild boars could play an effective role in the creation of specific microhabitat resources for plants and animals. Here, we tested the hypothesis that wild boar affects the habitat suitability to threatened butterflies, by evaluating the influence of rooting on multiple key aspects of the biology and ecology of the Mediterranean endemic Zerynthia cassandra. Namely, we used Z. cassandra as a model to test the effects of wild boar rooting on adult foraging opportunities, host plant occurrence, and oviposition site selection. We found that herbaceous communities disturbed by wild boar rooting have a higher proportion of plants representing nectar resources for early-flying butterflies. We also discovered that wild boar rooting positively influences the occurrence and abundance of the larval host plant of Z. cassandra, as well as the butterfly site selection for egg-laying. Our results indicate that wild boars may locally prove beneficial to endangered butterflies by favoring habitat quality and availability, and their role as ecosystem engineers should thus be further investigated to improve species and habitat management and conservation actions. [ABSTRACT FROM AUTHOR]

Tree mortality can fundamentally affect soils, which in turn shape forest regeneration and dynamics. Here, we quantify the dynamics of soil volumes associated with tree mortality, parsing effects by mode of tree death (broken vs uprooted) and species. The concept of ecosystem biogeomorphic succession was also tested. We used repeated tree censuses carried out in ten European and North American forests, differing in species composition, climate, and disturbance regimes. Development of more than 172,000 individual trees was recorded over periods of up to 48 years, during which more than one-third of the trees died. Biogeomorphic impact of deaths was modeled using allometry and field measurements. Tree uprooting-related soil volumes accounted annually for 0.01–13.5 m3ha−1, reaching maximum values on sites with infrequent strong windstorms (European mountains). The redistribution of soils related to trees that died standing ranged annually between 0.17 and 20.7 m3ha−1 and were highest in the presence of non-stand-replacing fire (Yosemite National Park, USA). Comparison of the results with known long-term erosion rates suggests that on certain sites over the last few millennia, tree uprooting may represent a significant driver of landscape erosion. Despite the key role of severe disturbances, the data showed potential for future increases in the intensity of biogeomorphic processes. The high biogeomorphic potential in some USA sites that has not yet been realized can be activated by external changes in the disturbance regime. Forests in Central Europe, on the other hand, are more sensitive to changes in biogeomorphic processes due to species turnover. [ABSTRACT FROM AUTHOR]

Burrowing mammals strongly impact plant communities. One of the main effects is accelerating nutrient cycling and thus promoting plant growth. This mechanism is well‐studied in grasslands and alpine habitats, but less is known about this phenomenon in arid, cold mountain environments. We studied ecosystem engineering by long‐tailed marmots (Marmota caudata) by measuring the content of plant nitrogen and phosphorus, as well as nitrogen stable isotopes in plant biomass and marmot feces in a distance gradient up to 20 m from marmot burrows in an extremely arid glacier valley in Eastern Pamir, Tajikistan. We also captured aerial images of the area inhabited by marmots to study the spatial distribution of vegetation. There was a weak relationship between the presence of burrows and vegetation cover on soil not covered by burrow material. Burrow mounds were not colonized by plants, as opposed to other studies, where mounds are often microhabitats that enhance plant diversity. A significant increase in N and P in aboveground green plant biomass in the proximity of burrows was found in one out of six studied plant species. Contrary to our expectations, stable N isotopes did not give further insight into N routing. We assume that plant growth is strongly limited by water availability, which prevents them from utilizing the local increase in nutrients, certainly provided by marmot activity. The results are contrary to numerous studies, which showed that the role of burrowing animals as ecosystem engineers increases with increasing abiotic stress, including aridity. This shows a lack of this type of study at the end of the gradient of abiotic factors. The presence of marmots and their burrows has surprisingly little effect on plant nutrient content and on vegetation cover in an extremely arid, cold mountain habitat. Burrow mounds are no microhabitats, as there is no plant succession on them. The results are contrary to previous studies on the effect size of ecosystem engineering in arid environments. [ABSTRACT FROM AUTHOR]

Leaf shelter construction by herbivorous insects can improve leaf quality, sometimes changing resultant herbivory. In two experiments in a Missouri (USA) deciduous forest we quantified the impact of leaf tie construction and changes to leaf quality on subsequent leaf damage.First, using eight Quercus species, we compared damage to single leaves versus experimental leaf ties that had been stocked with either Pseudotelphusa quercinigracella (Gelechiidae) or Psilocorsis cryptolechiella (Depressariidae) to determine how initial leaf quality (total phenolics) influenced damage caused by shelter inhabitants. Skeletonization by leaf tying caterpillars and leaf edge chewing by free feeding species were 12.2× and 1.3× greater on tied than on non‐tied leaves, respectively. July and September leaf phenolic content had a slight positive effect on the probability of skeletonization, none on the probability of edge damage, and a weakly positive or negative effect on the intensity of skeletonization and edge damage, depending on leaf position.Second, we created experimental leaf ties, protected from herbivores, on the same Quercus species to determine whether tie formation changes leaf quality (total phenolics, nitrogen, water, toughness). Tie formation decreased phenolics, but this change was predicted to add only 0.8% leaf area loss.Synthesis. Herbivory increased dramatically when leaves were in ties, with the effect mostly due to the tie itself rather than a change in leaf quality. We predict that the advantages of building and using leaf ties in this system are more likely to be escape from natural enemies and changes in abiotic factors. [ABSTRACT FROM AUTHOR]

Glacier forelands are among the most rapidly changing landscapes on Earth. Stable ground is rare as geomorphic processes move sediments across large areas of glacier forelands for decades to centuries following glacier retreat. Yet, most ecological studies sample exclusively on stable terrain to fulfill chronosequence criteria, thus missing potential feedbacks between geomorphic disturbances and vegetation colonization. By influencing vegetation and soil development, such vegetation‐geomorphic disturbance feedbacks could be crucial to understand glacier foreland ecosystem development in a changing climate. We surveyed vegetation and environmental properties, including geomorphic disturbance intensities, in 105 plots located on both stable and unstable moraine terrain in two geomorphologically active glacier forelands in New Zealand and Switzerland. Our plot data showed that geomorphic disturbance intensities permanently changed from high/moderate to low/stable when vegetation reached cover values of around 40%. Around this cover value, species with response and effect traits adapted to geomorphic disturbances dominated. This suggests that such species can act as "biogeomorphic" ecosystem engineers that stabilize ground through positive feedback loops. Across floristic regions, biogeomorphic ecosystem engineer traits creating ground stabilization, such as mat growth and association with mycorrhiza, are remarkably similar. Nonmetric multidimensional scaling revealed a linked sequence of decreasing geomorphic disturbance intensities and changing species composition from pioneer to late successional species. We interpret this linked geomorphic disturbance‐vegetation succession sequence as "biogeomorphic succession," a common successional pathway in unstable river and coastal ecosystems across the world. Soil and vegetation development were related to this sequence and only advanced once biogeomorphic ecosystem engineer species covered 40%–45% of a plot, indicating a crucial role of biogeomorphic ecosystem engineer stabilization. Different topoclimatic conditions could explain variance in biogeomorphic succession timescales and ecosystem engineer root traits between the glacier forelands. As glacier foreland ground is widely unstable, we propose to consider glacier forelands as "biogeomorphic ecosystems" in which ecosystem structure and function are shaped by geomorphic disturbances and their feedbacks with adapted plant species, similar to rivers and coasts. [ABSTRACT FROM AUTHOR]

The microphytobenthos (MPB) is a key determinant of ecological processes occurring in coastal sediments, where it functions as a trophic resource, sediment stabiliser and mediator of nutrient cycling and bentho-pelagic coupling. Endobenthic bioturbators are also important components of coastal sediments, wherein they influence ecosystem functioning principally through high sediment and pore-water manipulation rates. However, understanding of how endobenthic engineer activities influence MPB components, especially in the context of global change processes, is limited. We made use of a factorial mesocosm experiment and an in situ optical tool (BenthoTorch) to quantify responses of cyanobacteria, green-algae, diatoms and total MPB biomass to (1) eutrophic vs mesotrophic and (2) high vs low temperature conditions at increasing densities of sandprawns (Kraussillichirus kraussi). These crustaceans are highly influential endobenthic engineers in southern Africa, being widely distributed in estuaries, lagoons and embayments. Findings from our experiment indicated that total MPB biomass and that of cyanobacteria and diatoms (the dominant constituents of MPB assemblages in mesocosms) decreased from controls to maximum sandprawn-density treatments, but predominantly under low temperature. Sediment boundary roughness increased with sandprawn density, suggesting that sandprawn effects on MPB biomass and that of cyanobacteria and diatoms under low temperature was likely sediment mediated, with deposition of residual burrow sediment to the sediment-water interface reducing microalgal productivity. All MPB metrics declined with high temperature, suggesting a physiological intolerance of the MPB assemblages to upper thermal conditions in our experiment or nutrient limitation due to temperature-induced increases in metabolism. Our findings highlight the potential for rising temperature to reduce MPB biomass, as has been reported for open ocean and lake phytoplankton assemblages. Our results also highlight the functional significance of sandprawns in structuring MPB assemblages in coastal ecosystems, but their sediment-mediated limitation of benthic cyanobacterial biomass may confer a degree of resilience to coastal benthic ecosystems against harmful cyanobacterial blooms. • Global change experiment understanding responses of benthic microalgae to eutrophication, warming and changes in bioturbator density. • Rising temperature depressed microalgal biomass. • Increasing sandprawn density led to a reduction in microalgal biomass. • Cyanobacterial biomass was reduced by sandprawns. • Sandprawns may be import in counteracting benthic cyanobacterial blooms in coastal ecosystems. [ABSTRACT FROM AUTHOR]

Abstract Burrowing mammals strongly impact plant communities. One of the main effects is accelerating nutrient cycling and thus promoting plant growth. This mechanism is well‐studied in grasslands and alpine habitats, but less is known about this phenomenon in arid, cold mountain environments. We studied ecosystem engineering by long‐tailed marmots (Marmota caudata) by measuring the content of plant nitrogen and phosphorus, as well as nitrogen stable isotopes in plant biomass and marmot feces in a distance gradient up to 20 m from marmot burrows in an extremely arid glacier valley in Eastern Pamir, Tajikistan. We also captured aerial images of the area inhabited by marmots to study the spatial distribution of vegetation. There was a weak relationship between the presence of burrows and vegetation cover on soil not covered by burrow material. Burrow mounds were not colonized by plants, as opposed to other studies, where mounds are often microhabitats that enhance plant diversity. A significant increase in N and P in aboveground green plant biomass in the proximity of burrows was found in one out of six studied plant species. Contrary to our expectations, stable N isotopes did not give further insight into N routing. We assume that plant growth is strongly limited by water availability, which prevents them from utilizing the local increase in nutrients, certainly provided by marmot activity. The results are contrary to numerous studies, which showed that the role of burrowing animals as ecosystem engineers increases with increasing abiotic stress, including aridity. This shows a lack of this type of study at the end of the gradient of abiotic factors.

The rapid origination and diversification of major animal body plans during the early Cambrian coincide with the rise of Earth's first animal‐built framework reefs. Given the importance of scleractinian coral reefs as ecological facilitators in modern oceans, we investigate the impact of archaeocyathan (Class Archaeocyatha) reefs as engineered ecosystems during the Cambrian radiation. In this study, we present the first high‐resolution, three‐dimensional (3D) reconstructions of branching archaeocyathide (Order Archaeocyathida) individuals from three localities on the Laurentian paleocontinent. Because branched forms in sponges and corals display phenotypic plasticity that preserve the characteristics of the surrounding growth environment, we compare morphological measurements from our fossil specimens to those of modern corals to infer the surface conditions of Earth's first reefs. These data demonstrate that archaeocyaths could withstand and influence the flow of water, accommodate photosymbionts, and build topographically complex and stable structures much like corals today. We also recognize a stepwise increase in the roughness of reef environments in the lower Cambrian, which would have laid a foundation for more abundant and diverse coevolving fauna. [ABSTRACT FROM AUTHOR]