OecologiaPub Date : 2025-03-04DOI: 10.1007/s00442-025-05682-8
Maya R Rayle, Jesse L Brunner, Nicole C Dahrouge, Erin L Keller, Tracy A G Rittenhouse
{"title":"Infection intensity and severity of Ranavirus transmission in juvenile wood frogs.","authors":"Maya R Rayle, Jesse L Brunner, Nicole C Dahrouge, Erin L Keller, Tracy A G Rittenhouse","doi":"10.1007/s00442-025-05682-8","DOIUrl":"10.1007/s00442-025-05682-8","url":null,"abstract":"<p><p>Ranaviruses are responsible for mass die offs of wood frog (Lithobates sylvaticus) tadpoles. What happens in between epidemics is less clear, but juvenile (metamorphosed) stages are hypothesized to move Ranaviruses among wetlands and introduce or reintroduce these viruses into wetlands, initiating new outbreaks. A key question is under what circumstances can juvenile L. sylvaticus infect susceptible conspecifics. We examined Ranavirus transmission between juvenile L. sylvaticus in two settings: first, we measured transmission from a Ranavirus-infected frog to a co-housed susceptible frog via cohabitation over a range of exposure periods. Second, we measured indirect transmission to susceptible frogs from a contaminated environment after a range of waiting times (i.e., from when the infected frog was removed to when the susceptible frog was exposed to the environment). We present evidence that juvenile frogs directly transmitted Ranavirus to susceptible frogs in all exposure periods (99.2% infected), with as little as 1 h of co-housing resulting in 95.8% of susceptibles infected. Indirectly, 96.8% of susceptible frogs became infected after as long as 48 h waiting times. Neither exposure period nor wait times influenced the probability of infection, because these probabilities are already high. In our linear regression models, susceptible frog viral load was significantly correlated with exposure period and cohort for the cohabitation experiment, while wait time was significantly correlated with viral load for the sequential habitation experiment. Collectively, our results suggest that Ranavirus transmission readily occurs between recently metamorphosed wood frogs and via terrestrial environmental exposure.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 3","pages":"46"},"PeriodicalIF":2.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11880146/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143542953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-03-01DOI: 10.1007/s00442-025-05675-7
Alison K Post, Andrew D Richardson
{"title":"Predicting end-of-season timing across diverse North American grasslands.","authors":"Alison K Post, Andrew D Richardson","doi":"10.1007/s00442-025-05675-7","DOIUrl":"10.1007/s00442-025-05675-7","url":null,"abstract":"<p><p>Climate change is altering the timing of seasonal vegetation cycles (phenology), with cascading consequences on larger ecosystem processes. Therefore, understanding the drivers of vegetation phenology is critical to predicting ecological impacts of climate change. While numerous phenology models exist to predict the timing of the start of the growing season (SOS), there are fewer end-of-season (EOS) models, and most perform poorly in grasslands, since they were made for forests. Our objective was to develop an improved EOS grassland phenology model. We used repeat digital imagery from the PhenoCam Network to extract EOS dates for 44 diverse North American grassland sites (212 site-years) that we fit to 20 new and 3 existing EOS models. All new EOS models (RMSE = 22-33 days between observed and predicted dates) performed substantially better than existing ones (RMSE = 43-46 days). The top model predicted EOS after surpassing a threshold of either accumulated cold temperatures or dryness, but only after a certain number of days following SOS. Including SOS date improved all model fits, indicating a strong correlation between start- and end-of-season timing. Model performance was further improved by independently optimizing parameters for six distinct climate regions (RMSE = 4-19 days). While the best model varied slightly by region, most included similar drivers as the top all-sites model. Thus, across diverse grassland sites, EOS is influenced by both weather (temperature, moisture) and SOS timing. Incorporating these new EOS models into Earth System Models should improve predictions of grassland dynamics and associated ecosystem processes.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 3","pages":"44"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143531692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-03-01DOI: 10.1007/s00442-025-05676-6
Lucie Thel, Christophe Bonenfant, Simon Chamaillé-Jammes
{"title":"Good moms: dependent young and their mothers cope better than others with longer dry season in plains zebras.","authors":"Lucie Thel, Christophe Bonenfant, Simon Chamaillé-Jammes","doi":"10.1007/s00442-025-05676-6","DOIUrl":"10.1007/s00442-025-05676-6","url":null,"abstract":"<p><p>In large herbivores, the timing of births often coincides with the seasonal peak of food resources availability, likely to improve juvenile survival and reduce reproduction costs. Some species, however, breed year-round, even in seasonal environments. Demographic processes, such as to what extent being born during the lean season reduces survival of juveniles and reproductive females, remain understudied in large mammals inhabiting tropical ecosystems. We investigated survival rates in plains zebras (Equus quagga) in Hwange National Park (Zimbabwe), a highly seasonal savanna ecosystem. We used capture-recapture models to analyse long-term demographic data (2008-2019). We investigated the effect of seasonality as a categorical (wet versus dry season) and continuous (duration of the dry season) variable on survival. We found little variability in early juvenile survival (φ = 0.458 ± 0.044 SE, < 6 m.o.), whereas late juvenile and yearling survivals were higher and decreased with increasing length of the dry season (from 0.850 ± 0.095 SE to 0.480 ± 0.120 SE). Female survival was high (> 0.703 ± 0.057 SE and up to 0.995 ± 0.006 SE) but decreased with exposure to the dry season in non-reproductive females. The probability of females becoming reproductive in the following year was not affected by the length of the dry season (0.423 and 0.420 for reproductive and non-reproductive females, respectively). Our results highlight the importance of individual quality in reproductive performance, as reproductive females seem to buffer the effect of environmental variability on their own survival and that of their foal.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 3","pages":"45"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-02-28DOI: 10.1007/s00442-025-05680-w
Rolando O Santos, W Ryan James, Jennifer S Rehage, Cody W Eggenberger, Justin S Lesser, Christopher J Madden
{"title":"Trophic niche dynamics of two fish mesoconsumers in adjacent coastal habitats with varying nutrient regimes.","authors":"Rolando O Santos, W Ryan James, Jennifer S Rehage, Cody W Eggenberger, Justin S Lesser, Christopher J Madden","doi":"10.1007/s00442-025-05680-w","DOIUrl":"10.1007/s00442-025-05680-w","url":null,"abstract":"<p><p>Changes of consumers' trophic niches, the n-dimensional biotic space that allows a species to satisfy its minimum requirements for population growth, are driven in part by shifts in the degree of individual resource use specialization within a population. Individual specialization results from complex trade-offs in inter- and intraspecific competition as organisms reduce niche overlap within a population or with heterospecifics. It is vital to build empirical knowledge on the trophic niche dynamics of consumers, given the role that niche dynamics play in food web stability, species coexistence, and population resilience, especially quantifying the trophic niche's expansion and contraction of coastal fish populations experiencing increasing frequency of environmental disturbance and habitat transformation. In coastal ecosystems, disturbances alter the connectivity, productivity, and nutrient regimes of aquatic habitats, which could lead to significant shifts in consumers' trophic niches. We investigated the trophic niche dynamics of two fish species Centropomus undecimalis (Common Snook) and Megalops atlanticus (Atlantic Tarpon), across two adjacent coastal lake systems of varying nutrient regimes (eutrophic vs. mesotrophic) and hydrological connectivity. In both systems, Snook had larger trophic niches than Tarpon. Also, the trophic niche size in the eutrophic system was larger than the mesotrophic system for both species. Snook and Tarpon used different prey resources, resulting in low niche overlap between species in both systems. Our results highlight how altered hydrological connectivity, and nutrient regimes can shift trophic niche dynamics of higher trophic-level consumers, likely due to changes in prey landscapes and shifts in the foraging ecology of species.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 3","pages":"43"},"PeriodicalIF":2.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143531710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-02-28DOI: 10.1007/s00442-025-05684-6
A Floren, P Horchler, P Sprick, T Müller
{"title":"The ecological role of Fraxinus for species diversity in floodplain forests.","authors":"A Floren, P Horchler, P Sprick, T Müller","doi":"10.1007/s00442-025-05684-6","DOIUrl":"10.1007/s00442-025-05684-6","url":null,"abstract":"<p><p>Little is known about the importance of different tree species in maintaining diversity and function. To address this, we fogged 99 trees (30 Fraxinus excelsior, 30 F. pennsylvanica, 21 Quercus robur, 12 Ulmus laevis and 6 Tilia cordata) in Elbe floodplain forests, resulting in 182,179 arthropods including 25,861 (14.2%) beetles. Ninety-two percent of all beetles and 65% of all species were canopy associated. Tourist beetles of the ground contributed 35% to the arboreal richness but only 8% to overall abundance, suggesting little influence on trophic interactions. The highest alpha and beta diversity was recorded on Fraxinus trees, mainly due to the high number of tourists in low abundance. On the contrary, Quercus or Ulmus were characterised by large numbers of associated species. The beetle communities, and even more so the entire communities of all orders, were dominated by predators, suggesting strong top-down control of herbivore populations. Phytophages were significantly more abundant on Quercus and Ulmus, while they represented less than 10% on the ashes. F. excelsior is a keystone species, and this includes the ability to maintain biodiversity and communities with different functional profiles. As a result of ash dieback and drought, F. excelsior has been severely reduced in these forests. Our extensive data show that F. excelsior and F. pennsylvanica are similar in many ecological features due to their taxonomic relationship, resulting in a similar diversity and functional composition of arthropod communities, indicating that F. pennsylvanica can at least partially fill the ecological role of the common ash.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 3","pages":"42"},"PeriodicalIF":2.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143524041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-02-28DOI: 10.1007/s00442-025-05683-7
François Brassard, Brett P Murphy, Simon Ferrier, Alan N Andersen
{"title":"Large-scale pyrodiversity is not needed to beget ant diversity in an Australian tropical savanna.","authors":"François Brassard, Brett P Murphy, Simon Ferrier, Alan N Andersen","doi":"10.1007/s00442-025-05683-7","DOIUrl":"10.1007/s00442-025-05683-7","url":null,"abstract":"<p><p>The hypothesis that pyrodiversity begets biodiversity is foundational to conservation management in fire-prone ecosystems and has received extensive research attention. However, empirical evidence for the hypothesis remains ambivalent. Moreover, few studies directly assess the key question of how much pyrodiversity is needed to conserve all species within a community. A novel way of addressing this is to use the biodiversity-maximisation approach developed for reserve selection as part of strategic conservation planning. We apply this approach to an ant dataset from a long-term fire experiment in northern Australia to establish how many of the six experimental fire treatments are required to represent all local ant diversity. We identified the treatment combinations required to maximise species richness and geometric mean abundance. We repeated this for six fire-activity classes based on cumulative fire intensity experienced by plots over the course of the experiment. We found that a very limited number of fire treatments or fire activity classes were needed to represent all of the highly diverse ant species and to maximise the geometric mean abundance of ants. We attribute this to the substantial small-scale heterogeneity of fire behaviour and vegetation structure within individual fire treatments. We conclude that high pyrodiversity at larger spatial scales is not required for sustaining ant biodiversity in our study system. We believe that a reserve selection approach is a powerful method for assessing how much pyrodiversity is needed to conserve biodiversity and recommend that it be applied to other taxa and other ecosystems.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 3","pages":"41"},"PeriodicalIF":2.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11870973/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143524038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-02-27DOI: 10.1007/s00442-025-05677-5
David P Gregovich, Gretchen H Roffler, Christina M Prokopenko
{"title":"Vegetation influences wolf fine-scale habitat selection and movement rate in a logged coastal rainforest.","authors":"David P Gregovich, Gretchen H Roffler, Christina M Prokopenko","doi":"10.1007/s00442-025-05677-5","DOIUrl":"10.1007/s00442-025-05677-5","url":null,"abstract":"<p><p>Vegetation and its modification by humans can shape wildlife habitat selection and movement. A better understanding of how wolves select and move through natural and human modified vegetative cover can be used to implement forest management that considers impacts on wolves and their prey. We analyzed fine-scale wolf habitat selection and movement in a coastal temperate rainforest (Prince of Wales Island, Alaska, USA) in relation to: (1) young (≤ 30 years) and old (> 30 years) logged areas, (2) continuous measures of vegetative cover (as estimated via LiDAR), and (3) distance to roads, using integrated step-selection analysis (iSSA). Wolves selected areas with less forest canopy and understory cover at the population level, although they switched to selecting understory when within logged forest stands. The continuous canopy and understory measures vary at a fine spatial scale and thus appear to better explain fine-scale wolf selection and movement than categorical landcover classes representing the age of logged stands. Wolf selection of young (≤ 30 years) and old (> 30 years) successional logged areas, and areas near roads, was mixed across individuals. All individual wolves avoided canopy cover, but varied in their selection of logged stands, understory, and roads. Similarly, there was variability in movement rate response across individual wolves, although at the population level wolves moved faster through old (> 30 years) logged areas and through areas with less understory vegetation. Open vegetation including that present recently after logging is selected by wolves, and facilitates wolf movement, but this effect may be ephemeral as vegetation undergoes succession.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 3","pages":"40"},"PeriodicalIF":2.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11868358/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143516208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-02-26DOI: 10.1007/s00442-025-05678-4
Guillermo G Gordaliza, José Carlos Miranda García-Rovés, Rosana López, Ismael Aranda, Luis Gil, Ramón Perea, Jesús Rodríguez-Calcerrada
{"title":"Herbivory legacy modifies leaf economic spectrum and drought tolerance in two tree species.","authors":"Guillermo G Gordaliza, José Carlos Miranda García-Rovés, Rosana López, Ismael Aranda, Luis Gil, Ramón Perea, Jesús Rodríguez-Calcerrada","doi":"10.1007/s00442-025-05678-4","DOIUrl":"10.1007/s00442-025-05678-4","url":null,"abstract":"<p><p>The concurring effect of herbivory by wild ungulates and drought events is experiencing a notable increase in Mediterranean and temperate forests. While many studies have addressed the influence of drought on plant susceptibility to herbivory, it appears crucial to comprehend the impact of prolonged browsing on the physiological response of plants to increasing water deficit. To this end, we analyzed the effect of long-term recurrent herbivory by ungulates on physiological, biochemical, anatomical and morphological variables of Ilex aquifolium and Fagus sylvatica saplings during the growing seasons of 2018 and 2019 in a mixed sub-Mediterranean forest. We compared plants growing within an exclosure fence since 2006 (unbrowsed) with plants growing outside (browsed) that were also fenced during the study to investigate herbivory legacy. Twelve years of herbivory pressure modified significantly plant functional performance. Independently of the species, browsed plants showed higher root-to-shoot ratio, stem cross-sectional area-to-leaf area ratio, predawn leaf water potential, leaf nitrogen concentration and leaf gas exchange rates than unbrowsed plants. Moreover, browsed plants had lower leaf bulk modulus of elasticity, and higher osmotic potential at full turgor and turgor loss point. Thus, herbivory modified the leaf economic spectrum towards a more resource-acquisitive and less water stress tolerant type. These results suggest that, once browsing has subsided, plants continue to reflect some legacy effects that make them more vulnerable to further abiotic and biotic stresses, which has implications for forest regeneration.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 2","pages":"39"},"PeriodicalIF":2.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11865174/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143502353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-02-25DOI: 10.1007/s00442-025-05679-3
T'ai H Roulston, Anne Larsen, Amber D Slatosky
{"title":"Death and diminishment: parasitoid flies (Diptera: Conopidae) reduce foraging efficiency before killing their bumblebee host.","authors":"T'ai H Roulston, Anne Larsen, Amber D Slatosky","doi":"10.1007/s00442-025-05679-3","DOIUrl":"10.1007/s00442-025-05679-3","url":null,"abstract":"<p><p>Host-parasitoid interactions typically result in either a dead parasitoid or a dead host. Understanding the effects of parasitoid success on a host can be estimated primarily as how much an early death curtails host reproduction. When parasitoids attack the nonreproductive caste of social insects, however, the effects are not the reduced reproduction of the host but rather the sum reduction in host contributions to its colony. In addition to the loss of host workdays due to premature death, there is potential for additional cost through reduction in foraging efficiency as the infection develops. To better understand these pre-lethal effects, we allowed conopid parasitoid flies (Conopidae) to infect workers from a colony of the bumblebee Bombus impatiens (Apidae) in the lab and then moved the colony to an outdoor location. Bumblebee foragers were monitored using RFID technology and an automated analytical balance positioned between the colony and the outside environment. We found that infected bumblebees foraged similarly to uninfected workers halfway through their fatal infections. Starting at day 6-7, however, infected bees took fewer trips per day, which resulted in a significant reduction in resources returned to the colony over the last 3 days of the experiment. Both infected and uninfected bees were likely to remain out of the colony at night after their fourth day foraging, but infected bees started staying out sooner. These pre-lethal effects of a developing parasitoid add to the negative effects of a shortened lifespan on host contribution to its colony.</p>","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 2","pages":"38"},"PeriodicalIF":2.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11861133/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143502340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OecologiaPub Date : 2025-02-24DOI: 10.1007/s00442-025-05674-8
Jenna M Zukswert, Matthew A Vadeboncoeur, Timothy J Fahey, Ruth D Yanai
{"title":"Correction: Treatment effects of nitrogen and phosphorus addition on foliar traits in six northern hardwood tree species.","authors":"Jenna M Zukswert, Matthew A Vadeboncoeur, Timothy J Fahey, Ruth D Yanai","doi":"10.1007/s00442-025-05674-8","DOIUrl":"10.1007/s00442-025-05674-8","url":null,"abstract":"","PeriodicalId":19473,"journal":{"name":"Oecologia","volume":"207 2","pages":"37"},"PeriodicalIF":2.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143483749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}