Important Refuge Research Articles

Habitat engineering by an apex predator generates spatial trophic dynamics across a temporal environmental stress gradient.

Ecosystem engineering is a facilitative interaction that generates bottom-up extrinsic variability that may increase species coexistence, particularly along a stress/disturbance gradient. American alligators (Alligator mississippiensis) create and maintain 'alligator ponds' that serve as dry-season refuges for other animals. During seasonal water recession, these ponds present an opportunity to examine predictions of the stress-gradient (SGH) and intermediate disturbance hypotheses (IDH). To test the assumption that engineering would facilitate species coexistence in ponds along a stress gradient (seasonal drying), we modelled fish catch-per-unit-effort (CPUE) in ponds and marshes using a long-term dataset (1997-2022). Stomach contents (n = 1677 from 46 species) and stable isotopes of carbon and nitrogen (n = 3978 representing 91 taxa) from 2018 to 2019 were used to evaluate effects of engineering on trophic dynamics. We quantified diets, trophic niche areas, trophic positions and basal-resource use among habitats and between seasons. As environmental stress increases, we used seasonal changes in trophic niche areas as a proxy for competition to examine SGH and IDH. Across long-term data, fish CPUE increased by a factor of 12 in alligator ponds as the marsh dried. This validates the assumption that ponds are an important dry-season refuge. We found that 73% of diet shifts occurred during the dry season but that diets differed among habitats in only 11% of comparisons. From wet season to dry season, both stomach contents and stable isotopes revealed changes in niche areas. Direction of change depended on trophic guild but was opposite between stable-isotope and stomach-content niches, except for detritivores. Stomach-content niches generally increased suggesting decreased competition in the dry season consistent with existing theory, but stable-isotope niches yielded the opposite. This may result from a temporal mismatch with stomach contents reflecting diets over hours, while stable isotopes integrate diet over weeks. Consumptive effects may have a stronger effect than competition on niche areas over longer time intervals. Overall, our results demonstrated that alligators ameliorated dry-season stress by engineering deep-water habitats and altering food-web dynamics. We propose that ecosystem engineers facilitate coexistence at intermediate values of stress/disturbance consistent with predictions of both the SGH and IDH.

More than garden plants: extending the conversation of urban gardens as an important refuge for Australian birds

Abstract Inadequacies in public protected area networks dictates that private land will play an important role in the conservation of biodiversity in the coming decades. Household gardens are a key example of private lands that can serve as refuges for biodiversity, with birds as a popular flagship for garden biodiversity. Discussion has focused heavily on the species of plant a resident might select to attract birds to their garden. In this paper, we describe additional and important factors that should form part of this broader conversation on gardens for birds and biodiversity, with a specific aim of drawing attention to species that are at risk of localised extinctions in modern urban landscapes – urban adaptors. We present our commentary in two themes: (a) mitigating threats to birds in the urban environment and (b) enhancing the habitat value of the urban environment for a broader range of bird species. We provide a synthesis of the research of recent years that has explored the urban environment and its ability to support birds, but importantly, we extend on this by bringing together topics that have been somewhat lacking in the discussion to date. In a new approach to this conversation, this paper brings together key topics that can no longer be considered in isolation if we are to make significant conservation gains in the environments were most Australians now reside.

Updated checklist of Angiosperms in an exceptional area of the Serra do Teixeira National Park (PARNA), Paraíba, Brazil

The Caatinga is the largest Seasonally Dry Tropical Forest (SDTF) in South America with diverse geomorphological features. The “altitude marshes”, exceptional areas with altitudes above 700 m that were established in the humid mountains of the Caatinga, shelter vegetation characteristic of other phytogeographic domains. Despite the importance of these areas for the Brazilian semi-arid region, several of them still remain unknown, or little known, floristically. This study aims to update the floristic inventory of angiosperms in the recently created Serra do Teixeira National Park (PARNA), previously called Pico do Jabre State Park, in the State of Paraíba, Northeast Brazil. The checklist was prepared through field trips between 2018 and 2020 and compiled from a list of species published in 2004. The study compiled 335 species distributed in 70 families and 220 genera, while Fabaceae, Malvaceae and Asteraceae were the most representative families. Species richness depending on altitude was initially observed to be increasing, however, upon reaching intermediate levels of the altitudinal gradient, a decline in richness was observed, which continued to decrease until the top of the massif. Of the total number of documented species, there are representatives widely distributed in the Brazilian territory (141 spp.) as well as species also associated with the phytogeographical domains of Caatinga (281 spp.), Cerrado (254 spp.), Atlantic Forest (263 spp.), Amazon (157 spp.), Pampa (76 spp.) and Pantanal (82 spp.). The results demonstrate that the PARNA of Serra do Teixeira constitutes an important refuge for plant biodiversity, especially in the semi-arid region of Paraíba and Brazil.

Islands of lichen diversity in urban environments: a hidden richness in botanical gardens

Botanical gardens in city centres are green islands, offering a sanctuary for diverse plant and fungal species amidst urban landscapes. Although lichens are not usually a primary focus in botanical gardens, these spaces can serve as important refuges. In this work, the epiphytic lichen biota has been investigated in the Botanic Garden of Pisa, to uncover the hidden elements of biodiversity of botanical gardens in terms of non-target organisms. A total of 57 epiphytic lichen taxa and one non-lichenized fungus were recorded, including several threatened species. Two species, Arthopyrenia platypyrenia and Coenogonium tavaresianum, are new records for Tuscany, while Lecania cyrtellina is so far known in the region as occurring only in the Botanic Garden of Pisa. Lichen colonization reflects the richness of tree species, while the diffused presence of nitrogen-tolerant lichens could be associated with urban environmental conditions. Comments on Arthopyrenia platypyrenia, Coenogonium tavaresianum, Gyalecta liguriensis, Lecania cyrtellina, Lecanographa amylacea, Micarea misella, Porina borreri, and Waynea stoechadiana are given.

Herpetofauna del campus El Cerrillo de la Universidad Autónoma del Estado de México

The El Cerrillo campus, Piedras Blancas, Toluca de Lerdo, State of Mexico, is part of Universidad Autónoma del Estado de México. This campus stands out as a space where academic, agricultural, and livestock activities converge. We documented the amphibian and reptile species present on the campus, recording 14 species in total, five of which are amphibians and nine reptiles. Nine of these species are listed under risk categories according to the NOM-059-SEMARNAT-2010. Additionally, all recorded species, except Spea multiplicate and Thamnophis eques, are endemic to Mexico, with one species being exclusive to the State of Mexico. Despite being in a disturbed area, El Cerrillo remains as an important refuge for local wildlife, highlighting its ecological and scientific value in the region.

Problems and challenges of lichen inventory in a changing environment: The case of the “Mszar” and “Redykajny” reserves in Olsztyn

The paper presents the state of knowledge of the lichen biota of the “Mszar” and “Redykajny” nature reserves, located in the “Las Miejski” urban forest complex in Olsztyn (north-eastern Poland). The results of the inventory conducted in 2024 are described, which are compared with published data collected in 1999–2001. So far, a total of 118 lichenized and three non-lichenized fungi have been identified in this area. Recent studies did not confirm the occurrence of 18 species, but at the same time showed 32 species new to the study area. The article discusses possible causes of changes in the species composition of the lichen biota over almost 25 years and the effectiveness of various methods of collecting data in the field. The results prove that both reserves are still important refuges of forest lichen biodiversity on a scale larger than just the area of Olsztyn’s urban forests.

Life on Green Patches: Diversity and Seasonal Changes of Butterfly Communities Associated With Wastelands of the Post-Industrial Central European City.

Urban wastelands are among the most neglected urban habitats. Our study demonstrated that those spatially restricted patches of vegetation are an important refuge for various species of butterflies. We have assessed the diversity, distribution patterns, and seasonal changes of butterfly communities based on two-year (2019-2020), quantitative studies at 5 urban wastelands in a large post-industrial city in Central Poland. Forty-six species of butterflies were recorded in the city. We have noticed homogeneity of fauna, although all investigated sites were characterised by high diversity and co-occurrence of species associated with different habitats (e.g., grasslands, woodlands). Most of the species were common in Central Poland, although we have also recorded the presence of more specialised butterflies. Bray-Curtis similarity analysis reflected mostly seasonal changes in species composition. Seasonal patterns were very similar at all investigated sites and during both seasons, pointing to relative stability. Urban wastelands hosted from 34 to 41 species. This pattern results from the high diversity of microhabitats and the co-occurrence of various plant species at single sites, which is very important for plant-dependent organisms like butterflies.

Temporal and spatial use of a freshwater lake by upstream and downstream migrating adult Atlantic salmon Salmo salar.

Atlantic salmon Salmo salar typically enter fresh water several months prior to spawning and just as pools can provide areas of refuge in river systems, lakes may also provide important refuge habitat during the spawning migration. Using acoustic telemetry we examined the spatial and temporal movements of wild and a ranched strain of Atlantic salmon in a freshwater lake where the main spawning areas were located upstream of the lake. Over the study period (2011-2014), returning adult wild salmon spent an average of 228 days in fresh water and 90% of that time in the lake. On entering the lake, most wild salmon moved quickly to the northern part of the lake, close to the main inflow, spending an average 76% of the time in this location. The average number of days wild fish were absent from the lake during the main spawning period varied between years, ranging from 10 to 26 days for females and 32 to 35 days for males. Seventy four per cent (17/23) of salmon spawners returned to the lake and two salmon subsequently died in the lake post-spawning. Atypically, two salmon were resident in the lake for the whole period in 2013/14. During the study, wild salmon were detected at depths within the top 5 m for 73% of the time. Median depths post-spawning were greater than in the pre-spawning period, when salmon were found to spend extensive periods at depths in excess of 10 m. In July 2013, when the lake was stratified, thermal regulation behaviour was observed in wild salmon, whereby salmon moved to cooler deeper water when water temperatures at 1 m exceeded 20°C. In contrast to wild salmon, the majority of ranch salmon returned to the traps downstream of the lake prior to the spawning period, which would be expected as they were released as smolts below the freshwater lake. Ranch fish spent an average 80% of the time in the vicinity of receivers in the south of the lake and an average 98% of the time within the top 5 m. However, two ranch females were resident in the lake until the following spring and one ranch female moved upstream into the river during the spawning period. Clearly, in this catchment the lake provides an important habitat for migrating adult salmon. In the context of climate change, where thermal and hydrological regimes in rivers are expected to change in response to changes in air temperature and precipitation patterns, the availability of deep lakes that stratify in the summer and cool water refuges in river systems is likely to play a key role in the sustenance and conservation of salmonid species. Information about the migration patterns of Atlantic salmon in undisturbed freshwater systems may also assist in resolving issues associated with fish passage in impacted rivers and inform management decisions.

Ptačí diverzita v historickém zámeckém parku – implikace pro ochranu biodiverzity v hospodářských lesích

Long-term trends of abundance and diversity of forest birds have been very stable over past decades in European managed forests. It can be caused by high heterogeneity on habitat scale. In European cultural landscapes, there is another habitat very similar to managed forests, and that is a historic manor park. The parks can even show higher bird diversity than managed forests. However, there is an evident knowledge gap related to long-term changes of bird abundance and diversity in the habitats of manor parks. In this study we observed long-term changes of bird community in the historic manor park Čechy pod Kosířem (Czech Republic) using comparison of bird territory mapping in 2022–2023 with older bird studies in this locality. We gained an overview of bird community changes in the manor park for the period of 1997–2023. Results show that the bird community in historic manor park was remarkably unvarying in abundance and diversity. Historic manor parks can be considered as important refuges for forest bird diversity in cultural landscapes. We discuss the research implications for conserving bird diversity in managed forests especially in connection with large old trees preservation providing heterogeneity of nest habitats.

Refuge identification as a climate adaptation strategy to promote fish persistence during drought

AbstractClimate change is leading to global increases in extreme events, such as drought, that threaten the persistence of freshwater biodiversity. Identification and management of drought refuges, areas that promote resistance and resilience to drought, will be critical for preserving and recovering aquatic biodiversity in the face of climate change and increasing human water use. Although several reviews have addressed the effects of droughts and highlighted the role of refuges, a need remains on how to identify functional refuges that can be used in a drought management framework to support fish assemblages. We synthesize literature on drought refuges and propose a framework to identify and manage functional refuges that incorporate species physiological tolerances, behaviours and life‐history strategies. Stream pools, perennial reaches and off‐channel habitat were identified as important drought refuges for fish. The ability of refuges to improve species resistance and resilience to drought requires careful consideration of the biology of the target species and targeted management to promote persistence, quality and connectivity of refuges. Case studies illustrate that management of drought refuges can be challenging because of competing demands for water, incomplete knowledge of ecological requirements for target species and the increasing occurrence of multi‐year droughts. Climate adaptation is increasingly important, and drought refuges can increase fish resistance and resilience to climate‐related drought across the riverscape.

Are evergreen mistletoes on deciduous hosts arthropod winter refugia?

ABSTRACT Deciduousness is rare among native New Zealand trees, however, non-native deciduous trees now dominate many landscapes. The native evergreen mistletoe Ileostylus micranthus parasitises many non-native deciduous trees, so may be a critically important winter refuge for foliage-dwelling arthropods in deciduous trees. We compared arthropod communities on mistletoes and their evergreen or deciduous hosts in Dunedin, Otago. Foliage samples of 19 hosts and 19 mistletoes parasitising them were collected in summer and winter. Summer samples harboured 1335 arthropods including 1216 mites (Arachnida: Acari), mostly in domatia of two hosts. Winter samples harboured 60 arthropods including 19 mites. Mites were only identified to order but the 160 non-mite arthropods recovered were identified to 26 species or morphospecies in 23 families and 11 orders. The most common non-mite arthropods on hosts were mealybugs (Hemiptera: Pseudococcidae), while bark lice (Psocoptera) were most common on mistletoes. Mistletoes hosted 13 non-mite taxa not found on hosts, which were more likely to be native than those also or only found on hosts. Significantly more non-mite arthropods were found on mistletoes in winter than on their deciduous hosts. There was no difference between mistletoes and evergreen hosts in non-mite arthropod abundance. Mistletoes on deciduous hosts supported higher non-mite arthropod taxonomic richness in winter and over both seasons than their hosts. Despite the small number of non-mite arthropods recovered, our study adds to evidence that mistletoes are important habitat refugia for arboreal arthropods during suboptimal climatic periods, which in our study was during winter on deciduous host trees.

Effects of isolation on invertebrate biodiversity among the bladderwrack Fucus vesiculosus

Geographic isolation is a factor that is known to affect species composition and diversity in marine systems. In this study, we tested the effects of geographic isolation on invertebrate fauna living among the belt-forming foundation species Fucus vesiculosus in the northern Baltic Sea. Sampling was carried out on reefs with varying levels of isolation (0.5, 1 and 2 km) in July 2021 in the Åland islands (between 59.96°N 20.24°E and 59.75°N 20.84°E). The total number of taxa, abundance, Shannon-Wiener index, Pielou’s evenness and biomass were calculated and the effects of isolation were tested using generalised linear models. Multivariate methods were used to analyse differences in the invertebrate community composition. Although the number of taxa and Shannon´s diversity index did not vary along the isolation gradient, the total abundance of fauna decreased with increasing isolation. In addition, some taxa-specific patterns were observed, e.g. the abundance of insect larvae decreased with isolation while isopods were more numerous in the most isolated locations. As diversity and the number of taxa were similar regardless of isolation, shallow Fucus vesiculosus belts likely act as important biodiversity refuges and potential stepping-stones for invertebrates in remote outer archipelago areas. In a changing climate, these kinds of refuges aiding species dispersal are likely to be even more important, and should be considered in conservation planning.

Scale dependency of taxonomic and functional diversity in pristine and recovered loess steppic grasslands

Widespread campaigns on forest restoration and various tree planting actions lower the awareness of the importance of grasslands for carbon sequestration and biodiversity conservation. Even lower attention is given to the conservation of biodiversity and ecosystem functioning in remnants of ancient, so-called pristine grasslands. Pristine grasslands generally harbour high biodiversity, and even small patches can act as important refuges for many plant and animal species in urbanised or agricultural landscapes. Spontaneous succession of grassland is frequently viewed as a cost-effective tool for grassland restoration, but its applicability is strongly dependent on many local to landscape-scale factors, and the recovery is often slow. It is therefore essential to monitor the success of grassland restoration projects that rely on spontaneous succession. We compared the species diversity and functional attributes of pristine and recovered grasslands by studying the taxonomic and functional diversity in thirteen (8 pristine and 5 recovered) loess steppic grasslands using differently sized sampling plots from 0.01 to 100 m2. Our results indicate that there are remarkable differences in taxonomic and functional diversity between pristine and recovered grasslands. We also found that during secondary succession there is a likely functional saturation of the species assembly in the first few decades of recovery, and while patterns and structure of recovered grasslands became quite similar to those of pristine grasslands, species richness and diversity still remained much lower. Pristine grasslands support considerable plant diversity, and species composition is slow to recover if destroyed by agricultural land use. This underlines the importance of preserving existing pristine grassland remnants, which might serve as sources of species for future restoration measures.

Identifying remnant biodiversity hotspots in Southern Asia reveals disequilibrium in mammalian communities

Identification of highly biodiverse areas has become a crucial step in protecting species richness, especially considering the rapid collapse of biodiversity and the limited funds available to avert, far less to reverse, these trends. Therefore, we aimed to identify the most important areas for the conservation of specified mammalian groups in Southern Asia, a region rich in biodiversity hotspots threatened by increasing rates of habitat loss and other anthropogenic activities. To achieve this, we modelled the occupancy of ungulates and of small, medium and large carnivorans at 20 study sites across the region and identified hotspots of species richness. We analysed the variation of estimated space use between different species groups and ranked areas according to their predicted importance for mammalian species conservation. Our results reveal a significant positive correlation in the spatial utilization patterns of competitive carnivores, yet no correlation among carnivores and their prey species, suggesting that anthropogenic impacts in the region are constraining species to coexist in only the few remaining suitable areas, superseding interactions between species guilds. Although the rank of site importance varied amongst species groups, we were able to identify a consensus on sites that are crucial for the conservation of all groups considered. Most of these top-ranking sites were located in the peninsular region of Thailand. We argue that, of the areas assessed, these sites represent the most important refuges for species conservation in the region, and their protection is critical for the maintenance of the biodiversity in Southern Asia.

Paleosol charcoal: 12,700 years of high-altitude mediterranean vegetation history in relation to forest fires in the southwestern baetic cordillera (Spain)

Mountain forests are sensitive ecosystems. This is why in recent years the dynamics of these forest ecotones have been researched from several different approaches. One of these has been the paleoecological perspective, which is particularly interesting in the mountainous areas of the Mediterranean region, where interactions between climate, vegetation and anthropic activities have been documented for millennia. This is the case of the Sierra de las Nieves Natural Park (southwestern Baetic Cordillera), a mountainous area that constitutes an important refuge for flora in southern Iberian Peninsula. At present, endemic trees such as Abies pinsapo and Quercus faginea subs. alpestris are found. However, its strategic geographical location may also have served in the past as a refuge for other tree taxa. In order to reconstruct the vegetation history in this protected natural area, this research aims to use pedoanthracological analysis in an unexplored area of this mountainous system. The results obtained have allowed to identify a new paleopopulation of Abies, a finding that provides new keys on the paleobiogeography of this species. This is the oldest evidence of this genus and at the highest altitude of those found to date in the southwestern Baetic Cordillera, which would confirm that this fir tree was present in high elevations of the Sierra de las Nieves during the Pleistocene-Holocene transition. Likewise, the first anthracological evidence of Pinus nigra/sylvestris type in the southwestern end of the Baetic Cordillera has been obtained. Forest fires could have been one of the main factors which would be determined the shaping and evolution of the vegetation landscape, as suggested by the fire events identified from the soil analysis. This information can be useful for the conservation and adaptive management of the most threatened forests and their habitats in the face of global change.

Forest pollinator richness declines with distance into burned areas

The effects of prescribed fire on forest pollinator communities are complex and incompletely understood. One of the least-studied questions concerns how these organisms are affected by the size, or spatial scale, of fire. We sought to address this by sampling bees (Hymenoptera: Apoidea), butterflies (Lepidoptera), and hover flies (Diptera: Syrphidae) at different distances along 500 m transects into forests burned every three years in the southeastern United States. We found combined pollinator richness to decline significantly with distance, being about 23.9 % lower near the centers of burn units than near the edges, and this did not change with time since fire. These patterns held true when small and large pollinators were analyzed separately, as well as for the richness of bees and butterflies (but not hover flies), and regardless of bee nesting guild. We found no relationship between the abundance of all pollinators and distance. However, the abundance of small pollinators decreased with distance whereas that of large pollinators increased. A competing model provided no support for the alternative hypothesis that the observed effects of distance can be explained by the length of road edges nearby as opposed to distance from unburned habitat. The richness and abundance of all pollinators combined and most taxonomic groups and species analyzed separately increased with increasing canopy openness as well as with increasing plant richness. Although pollinator richness declined with distance into large burns and small species appear to be particularly sensitive, we also found the richness and abundance of pollinators to decrease with time since fire. Our results show that fire can improve local conditions for pollinators but that unburned habitats serve as important refugia or sources of flowers following fire, underscoring the importance of pyrodiversity in managed landscapes.

COSMARIUM RETUSIFORME VAR. INCRASSATUM GUTWIŃSKI 1890 (ZYGNEMATOPHYCEAE, STREPTOPHYTA) – NEW RECORD OF RARE DESMID IN UKRAINE

Purpose. Adding a new taxon of the genus Cosmarium to the desmids flora of Chernihiv Polesie. Methodology. The landscape reserve of national significance “Zamglai” is one of the largest eutrophic swamps in the Chernihiv Polesie, which is an important refugium of hydrophilic phytodiversity of the forest zone, a place of concentration of a number of rare species of the boreal group and representatives of various biotic complexes. During the field research of the Zamglai bog complex, algal samples were collected and fixed with 4 % formalin for further study in laboratory conditions; pH and electrical conductivity of water were measured with a portable pH and conductivity meter. Microscopic examination of the samples was carried out using a light microscope equipped with a camera for taking microphotos. Identification manuals and monographs of the leading Ukrainian (Palamar-Mordvintseva, 1986, 2005) and European desmidiologists (Lenzenweger, 1999) were used for species identification.The iconotype provided in the original description of the newly recorded taxon (Gutwiński, 1892) was used. Scientific novelty. The second record in Ukrainian desmidioflora of a rare taxon from the genus Cosmarium is documented. Previously it was discovered 134 years ago (Gutwiński 1890) in the Roztochchia-Opillja mountain region, namely in the vicinity of Lemberg (former Kingdom of Galicia and Lodomeria, a part of the Austro-Hungarian Monarchy – now Lviv, Ukraine). This taxon was found by the authors for the first time in the Ukrainian Polesie (Chernihiv Polesie). Description, cell dimensions and microphotographs in three views are included in this publication. Conclusions. The description and photographs of the three cell views of the taxon given in the article fill the gaps in the illustrative material of the national reference publications (Palamar-Mordvintseva 1986: 167, fig. 37 item 16) and create better conditions for identification and new records of this taxon in Ukraine. The distribution area of Cosmarium retusiforme var. incrassatum Gutwiński 1890 has been expanded. The flora of desmids of the Ukrainian Polesie is enriched with a new infraspecific taxon.

The potential range of west Asian apple species Malus orientalis Uglitzk. under climate change

The wild relatives of cultivated apples would be an ideal source of diversity for breeding new varieties, which could potentially grow in diverse habitats shaped by climate change. However, there is still a lack of knowledge about the potential distribution of these species. The aim of the presented work was the understand the impacts of climate change on the potential distribution and habitat fragmentation of Caucasian crab apple (Malus orientalis Uglitzk.) and the designation of areas of high interest according to climatic conditions. We used the MaxEnt models and Morphological-Spatial Analysis (MSPA) to evaluate the potential distribution, suitability changes, habitat fragmentation, and connectivity throughout the species range in Turkey, Armenia, Georgia, Russia, and Iran. The results revealed that the potentially suitable range of M. orientalis encompasses 858,877 km², 635,279 km² and 456,795 km² under the present, RCP4.5 and RCP8.5 scenario, respectively. The range fragmentation analysis demonstrated a notable shift in the edge/core ratio, which increased from 50.95% in the current scenario to even 67.70% in the future. The northern part of the range (Armenia, northern Georgia, southern Russia), as well as the central and western parts of Hyrcania will be a core of the species range with suitable habitats and a high connectivity between M. orientalis populations and could work as major refugia for the studied species. However, in the Zagros and central Turkey, the potential range will shrink due to the lack of suitable climatic conditions, and the edge/core ratio will grow. In the southern part of the range, a decline of M. orientalis habitats is expected due to changing climatic conditions. The future outlook suggests that the Hyrcanian forest and the Caucasus region could serve as important refuges for M. orientalis. This study helps to understand spatial changes in species’ range in response to climate change and can help develop conservation strategies. This is all the more important given the species’ potential use in future breeding programs aimed at enriching the gene pool of cultivated apple varieties.

Kelp holdfast microclimates buffer invertebrate inhabitants from extreme temperatures

Climate change is altering environmental conditions, with microclimates providing small-scale refuges within otherwise challenging environments. Durvillaea (southern bull kelp; rimurapa) is a genus of large intertidal fucoid algae, and some species harbour diverse invertebrate communities in their holdfasts. We hypothesised that animal-excavated Durvillaea holdfasts provide a thermal refuge for epibiont species, and tested this hypothesis using the exemplar species D. poha. Using a southern Aotearoa New Zealand population as a case-study, we found extreme temperatures outside the holdfast were 4.4 °C higher in summer and 6.9 °C lower in winter than inside the holdfast. A microclimate model of the holdfasts was built and used to forecast microclimates under 2100 conditions. Temperatures are predicted to increase by 2–3 °C, which may exceed the tolerances of D. poha. However, if D. poha or a similar congeneric persists, temperatures inside holdfasts will remain less extreme than the external environment. The thermal tolerances of two Durvillaea-associated invertebrates, the trochid gastropod Cantharidus antipodum and the amphipod Parawaldeckia kidderi, were also assessed; C. antipodum, but not P. kidderi, displayed metabolic depression at temperatures above and below those inside holdfasts, suggesting that they would be vulnerable outside the holdfast and with future warming. Microclimates, such as those within D. poha holdfasts or holdfasts of similar species, will therefore be important refuges for the survival of species both at the northern (retreating edge) and southern (expanding edge) limits of their distributions.

More trees and fewer roads: the importance of local and landscape features for insectivorous bats in open urban green spaces

Context Urbanisation poses new challenges for wildlife worldwide, and recent research suggests that urban parks, although highly modified, may act as important refuges. Insectivorous bats can persist in urban landscapes and play an important role in keeping insect populations in balance. Previous research on use of urban landscapes by these bats has often focused on patches of remnant bushland within cities, but their use of highly modified open spaces is not well understood. Aims We aimed to determine the use of open green spaces (e.g. open parks, sports ovals) by insectivorous bats in Melbourne, Australia and to identify landscape factors that influence their presence and activity level. Methods We conducted passive acoustic surveys at 35 sites across greater Melbourne. Once species were identified from the echolocation call data, we modelled species richness, total activity and activity of individual species against landscape and weather variables, using Generalised Linear Mixed Models and Generalised Additive Mixed Models. Key results Across 557 detector nights, we identified at least 11 of the 17 species recorded to occur in Melbourne. Both species richness and activity were greater in areas with more nearby trees and lesser in areas with more roads. There were weaker species-specific relationships between bat activity and both distance to the nearest water source and Normalised Difference Vegetation Index. Species richness and activity levels were lower on nights with a lower temperature at dusk, higher rainfall and stronger wind. Conclusions Our results show that multiple bat species consistently use Melbourne’s open green spaces, highlighting the potential habitat value of these areas, especially those surrounded by high tree densities and fewer roads. Implications Insectivorous bats play important roles within ecosystems and bring benefits to human society. To encourage the diversity and activity of insectivorous bats in urban landscapes, we recommend retaining and increasing indigenous vegetation surrounding open areas in urban parks, as well as more strategic planning of new urban parks that further increases tree density in cities.