Forest fires create substrates critical for saproxylic and fire-favoured species, but fire suppression has reduced their availability, contributing to declines in these pyrophilous species populations. While beetle responses to fire have been commonly studied in pine-dominated (Pinus sylvestris) forests, much less is known about how burned birch (Betula pendula/pubescens), another fire-favoured tree species, supports beetle communities. We assess differences in beetle communities between prescribed-burned birch and pine in boreal forests of Sweden, 0-2 years post-fire. We analysed beetle species richness, abundance and species assemblage on birches and pines of varying diameters and used tree vitality and char height as proxies for fire severity. In general, birches hosted higher beetle species richness than pines with distinct beetle community composition, driven by their higher mortality post-fire, whereas the number of red-listed species was higher on pines. Neither species richness nor abundance was related to tree diameter. Beetle abundance on birch increased with char height of the trunk, whereas species richness decreased, suggesting an increase in specialized species. Implications for insect conservation: Birch, even with small diameters, contributes to the conservation of saproxylic and pyrophilous beetle diversity following prescribed burning and should be retained and promoted alongside pine in prescribed burning and post-fire restoration planning.
Agricultural intensification and the loss of floral resources are suspected factors in bumble bee declines in North America. Understanding the effects of land use on bumble bee communities at the local and landscape scale is important to support conservation efforts. We surveyed 55 prairie and grassland sites in a highly agricultural landscape in 2023 and 2024. We used a multispecies occupancy model to estimate effects of site characteristics on both community-level and species-level occupancy probability. We also evaluated the relationship between species richness and the land cover within 1.6 km of sites. We detected 13 species of bumble bees, including four that are threatened or endangered. Bumble bee community occupancy probability was positively associated with local plant diversity (beta = 0.545, 95% CRI: 0.0293, 1.22) and was generally higher in more forested landscapes (beta = 0.530, 95% CRI: -0.0727, 1.24), but this varied greatly among species. Species richness was significantly lower at sites with high corn/soybean land cover (Spearman's rank correlation coefficient rho = -0.318, 95% CRI: -0.570, -0.0705) and significantly greater at sites with high forest cover within 1.6 km (rho = 0.491, 95% CRI: 0.273, 0.687). Maintaining sites with a continuous availability of flowering plants during bumble bee foraging periods within proximity to forests may be an effective means of sustaining diverse bumble bee communities in highly agricultural landscapes.
Although butterflies are abundant in tropical and subtropical grassland, savanna and shrubland biomes in sub-Saharan Africa, they are often overlooked in land-use planning in the tropics and rarely assessed for their responses to conservation interventions. We compared butterfly diversity patterns across a protection gradient in the Katavi-Rukwa Ecosystem (KRE), western Tanzania. We surveyed 105 randomly selected sites spanning national park (NP), game reserve (GR), game-controlled areas (GCA), forest reserve (FR) and unprotected areas (UA) during the 2021 dry season. Species were classified by habitat specialization, larval host-plant specialization and wingspan. Environmental variables were derived from remote sensing and spatial datasets. We analysed butterfly richness, abundance, functional composition and assemblage structure, and evaluated the influence of environmental conditions, habitat type and protection status using generalized linear models, multivariate ordination, PERMANOVA and additive diversity partitioning. We recorded the highest butterfly richness and abundance in GR, while NP supported comparatively lower richness and abundance. Vegetation productivity (EVI), percent bare soil cover and human population density were significant drivers of assemblage structure. Through regression analysis, EVI and human population density emerged as key predictors of species richness, with higher productivity supporting greater richness and higher human population density associated with reduced species richness. Additive partitioning analysis revealed that beta-diversity, particularly turnover among protection types, was the main contributor to total richness. We recommend conservation strategies in KRE to move beyond formal protection status and consider the role of moderately managed landscapes and environmental conditions in maintaining butterfly diversity. Ingawa vipepeo wanapatikana kwa wingi katika biomu za nyanda za majani za kitropiki na nusutropiki, savanna, na maeneo ya vichaka kusini mwa Jangwa la Sahara, mara nyingi hupuuzwa katika mipango ya matumizi bora ya ardhi katika maeneo ya tropiki na ni nadra kutathminiwa kuhusu namna wanavyoitikia afua za uhifadhi. Kutokana na unyeti wao kwa afua hizo, tulilinganisha mifumo ya anuwai ya vipepeo katika maeneo yenye hadhi tofauti za uhifadhi ndani ya Mfumo-ikolojia wa Katavi-Rukwa (KRE) magharibi mwa Tanzania. Tulifanya utafiti katika maeneo 105 yaliyochaguliwa kwa nasibu, yakihusisha madaraja matano ya hadhi ya kisheria ya uhifadhi: hifadhi ya taifa (NP), pori la akiba (GR), maeneo tengefu ya wanyamapori (GCA), hifadhi ya misitu (FR), na maeneo yasiyohifadhiwa (UA), wakati wa msimu wa kiangazi wa mwaka 2021. Tulitumia uchambuzi wa kitakwimu kutathmini aina na wingi wa vipepeo katika madaraja matano ya uhifadhi. Tulirekodi aina na wingi mkubwa zaidi wa spishi za vipepeo katika mapori ya akiba na maeneo tengefu ya wanyamapori ikilinganishwa na hifadhi ya taifa yenye ulinzi mkali. Kwa kutumia Canonical Analysis of Principal Coordinates, tulibaini kuwa EVI, asilimia ya udongo ulio wazi, na msongamano wa watu ni viashiria muhimu vilivyoathiri muundo wa jamii za vipepeo. Kupitia generalized linear models, tija ya uoto wa, iliyopimwa kwa EVI, na msongamano wa watu viliibuka kuwa viashiria muhimu vya utajiri wa spishi. Tija kubwa ya uoto iliunga mkono utajiri mkubwa wa spishi, ilhali msongamano mkubwa wa watu ulihusishwa na kupungua kwa utajiri wa spishi. Uchambuzi wa mgawanyo wa ziada ulionyesha kuwa beta-anuwai kati ya aina za uhifadhi ndiyo iliyochangia zaidi utajiri wa jumla wa spishi Tunapendekeza mikakati ya uhifadhi katika KRE ipanue mtazamo zaidi ya hadhi rasmi za uhifadhi na izingatie mchango wa mandhari zinazosimamiwa kwa kiwango cha wastani pamoja na hali za kimazingira katika kudumisha anuwai ya vipepeo.
Studying insect decline in human-dominated landscapes, especially in intensively managed agricultural areas, requires understanding its drivers. Studies of cavity-nesting bees and wasps with trap nests provide information on the number of locally reproducing species and their potential offspring, and how this relates to local resources and landscape diversity. We investigated insect communities across all major habitat types in agricultural landscapes in Germany using a grid-based design to evenly and proportionally cover the major habitats of our landscapes. The landscape plots covered a gradient from complex landscapes with a variety of habitats to simple landscapes dominated by arable land. At the local scale, we found that bee species richness was highest in grasslands and traditional orchards and lowest in forests, mirroring patterns of local floral resources. However, unlike wasp richness, bee richness was unaffected by local hedgerow cover. Wasp species richness was highest in forests, followed by orchards and lowest in grasslands and arable land. Brood cell abundance of the dominant bee species (Osmia bicornis, O. cornuta) was highest in orchards and lowest in forests, whereas the dominant wasp species (Ancistrocerus nigricornis, Trypoxylon figulus) showed the opposite pattern. Neither group was affected by hedgerows. At the landscape scale, landscape diversity neither affected species richness nor the number of brood cells of bees and wasps. Our results highlight the importance of local habitat diversity in agricultural landscapes for supporting diverse cavity-nesting bee and wasp communities, as bees benefit from flower-rich grasslands and orchards, while wasps rely on forest resources. To counteract insect decline, conservation efforts should target both seminatural and managed habitats.
Abstract Subterranean ecosystems harbour fauna moulded by extreme and stable conditions such as absence of light, narrow temperature ranges, high humidity and low availability of organic matter. The adaptations of cave fauna, coupled with the isolation of populations, often lead to a higher incidence of endemics and greater vulnerability to environmental changes. These ecosystems face severe threats caused by pollution and overexploitation, habitat loss and climate change, particularly evident in areas of increased human pressure as capitals of countries. In Portugal, more than 100 endemic cave‐adapted species have been identified, and close to its capital, highly urbanized and industrialized, the Greater Lisbon area hosts several unique endemic subterranean species that lack protection measures. We assessed the invertebrate faunal biodiversity and the conservation status of caves in the Greater Lisbon area. Our results show that arthropods dominate, in abundance and richness, the caves of the Greater Lisbon area, followed by molluscs. Ten endemic subterranean species were found, and of the 20 troglobionts recorded, 11 were found in only one cave, 5 in two caves and 4 in three or more. The overall most diverse was Poço Velho Cave, and the most troglobiont‐diverse was Alvide Cave, both in Cascais. Based on our results, we propose a preliminary conservation priority hierarchy for the studied caves. Our findings reveal that Greater Lisbon harbours irreplaceable subterranean habitats, that support diverse and exclusive invertebrate fauna, which face tremendous threats to their survival, underscoring the need for targeted conservation planning and biodiversity monitoring.
