ABSTRACT Long‐term tree‐growth records provide critical insights into how tropical montane forests respond to climatic variability over decadal to centennial timescales. In the tropical montane cloud forests of Postrervalle, Bolivia (18° S, 63° W), distinct annual rings in Juglans australis and Cedrela angustifolia allowed the development of three tree‐ring width chronologies: Los Juncos (JUN, J. australis ), Los Churcos (CHU, C. angustifolia ), and Loma de las Estacas (LDE, C. angustifolia ), spanning 207, 186, and 77 years, respectively. The chronologies include 39, 25, and 21 trees. Radial growth of J. australis was positively related to dry‐season precipitation (April–October; r = 0.52, p < 0.05) and negatively related to dry‐season temperatures (July–October; r = −0.48, p < 0.05). Growth of C. angustifolia was positively associated with wet‐season precipitation at CHU (November–March; r = 0.52, p < 0.05) and LDE (November–January; r = 0.48, p < 0.05). Negative temperature relationships occurred during July–November at CHU ( r = −0.57, p < 0.05) and January–February at LDE ( r = −0.37, p < 0.05). Narrow rings in both species were associated with warmer and drier conditions, with climatic differences emerging earlier in J. australis . At longer timescales, J. australis showed a sustained increase in standardized growth since the mid‐1970s, whereas C. angustifolia showed no comparable trend. These results reveal species‐specific climate sensitivity and provide a baseline for anticipating forest responses to ongoing climate change.
ABSTRACT Habitat selection is a key ecological process that influences resource acquisition, reproduction, survival, and therefore, fitness. Assessing this process also informs on species management and conservation. However, habitat selection has been understudied in tropical snakes, despite their great diversity and ecological importance. This omission stems from the inherent challenges of researching snakes in the field. We employed radiotelemetry to investigate the microhabitat selection patterns of the Mesoamerican rattlesnake ( Crotalus simus ), a tropical pit viper with a Nearctic origin, at its southernmost distribution. Throughout 2023 and 2024, we monitored 11 adult snakes in Nosara, Costa Rica. We compared environmental and structural features between snake‐selected sites and random sites to assess differences in habitat use between diel period (daytime/nighttime) and origin status (resident/translocated). Rattlesnakes preferred leaf litter as substrate while avoiding other substrate types. They selected higher temperatures, although the effect was stronger during daytime. Humidity preference was stronger in resident individuals and during daytime, while understory complexity was preferred by translocated individuals during the day and avoided by residents at night. All individuals preferred greater distances to water sources and semi‐open areas, favoring locations with lower canopy cover and farther from large trees. Finally, selection patterns for distances to the nearest small tree and fallen log depended on origin status. Our findings demonstrate that microhabitat selection in C. simus is non‐random and shaped by diel period and origin status. The novel insights provided here represent an important first step toward a deeper understanding of this species' ecology.
ABSTRACT Local community perceptions are crucial for effective biodiversity conservation and sustainable land use management. However, limited attention has been given to how local community perceptions and ethnobotanical knowledge shift along spatial gradients. This study investigated local perceptions of forest patch dynamics and ethnobotanical knowledge shifts across a rural–urban gradient in Central highland of Ethiopia. Data were collected via household surveys ( N = 385) and key informant free‐listing ( N = 45), and analyzed using Proportional Odds Logistic Regression (POLR), Smith's Salience Index (SSI), and Transformation‐based Principal Component Analysis (tb‐PCA). POLR modeling revealed that spatial gradient and socioeconomic factors significantly shape local community perceptions. Rural and urban respondents exhibited lower odds of perceiving forest patch coverage as stable or increasing compared to the peri‐urban baseline. Urban respondents expressed more optimism regarding plant diversity status (mean score = 1.63) despite demonstrating lower botanical knowledge (22 listed total species: 17 native, 5 exotic). Conversely, rural communities held the most pessimistic perceptions (mean score = 1.38) while retaining a high plant species recall (59 listed total species: 54 native, 5 exotic). Free‐listing salience and tb‐PCA ordination reflected a structural transition from native‐dominated ecological memory ( Juniperus procera , SSI = 0.345; Olea europaea , SSI = 0.272) in rural areas toward commercial exotics ( Eucalyptus globulus , Cupressus lusitanica ) in urban areas. Taken together, this study demonstrates a potential divergence between community perceptions and botanical ethnobotanical knowledge along the rural–urban gradient. Urban greening and restoration practices should integrate rural ethnobotanical knowledge to prevent floristic homogenization and subsequent loss of biodiversity.
ABSTRACT Urban environments can generate substantial spatial and temporal variation in pollinator assemblages, floral traits, and resource availability, yet how plant reproduction is maintained under such heterogeneous conditions remains poorly understood, particularly in tropical cities. In Nicotiana glauca (Solanaceae), floral traits and pollinator assemblages vary among natural populations, but information from urban environments is lacking. We investigated pollination dynamics and reproductive success of N. glauca across a heterogeneous urban landscape in the high tropical Andes by integrating flower visitation, floral trait variation, functional morphology, and reproductive output. Flower visitation varied strongly among visitor groups, times of day, and urban regions. Hummingbirds were the only legitimate pollinators, whereas bees acted exclusively as nectar robbers. We report Colibri coruscans and Elliotomyia chionogaster as pollinators of N. glauca for the first time. Despite pronounced spatial and temporal variation in floral traits and visitor assemblages, including complete spatial turnover between hummingbird species, fruit set remained consistently high (> 90%) across all urban regions. No fruits were produced in pollinator‐excluded flowers, suggesting dependence on animal‐mediated pollination. Although flower tube length generally exceeded hummingbird bill length, both species appeared functionally compatible with the flowers and carried pollen on their beaks during visitation. Our results show that N. glauca maintains high reproductive success across heterogeneous urban environments, through hummingbird‐mediated pollination, highlighting the resilience of some plant–pollinator interactions in rapidly urbanizing tropical landscapes.
ABSTRACT Annual meetings of the Association for Tropical Biology and Conservation (ATBC) provide a window into emerging research priorities, conceptual shifts, and methodological advances in tropical biology and conservation. Here, we synthesize lessons and outcomes from the 61st ATBC Annual Meeting (ATBC 2025) held in Oaxaca, México, and situate them within the broader trajectory of ATBC conferences to identify continuities, emerging directions, and gaps. ATBC 2025 convened 1161 participants from 63 countries, providing a timely platform to examine how research in tropical biology and conservation is responding to accelerating socioecological change. Analyses of symposia, oral and poster presentations, and plenary sessions revealed three overarching messages. First, compound disturbances—such as interactions between land‐use change and climate extremes—are increasingly reshaping tropical ecosystems and require integrative research and management approaches. Second, effective conservation and restoration depend on equity‐centered frameworks that meaningfully engage Indigenous Peoples and local communities through collaborative governance and coproduced knowledge. Third, rapid methodological innovation—from microbiome studies to artificial intelligence and remote sensing—continues to expand analytical capacity, although its transformative potential depends upon socially grounded and place‐based contexts. The meeting also highlighted science–action linkages, exemplified by the “Declaration on the Social–Ecological Impacts of Agave Monocultures for Mezcal Production” and ATBC's carbon offset initiative developed with CORENCHI, a community‐led civil association conserving tropical cloud forests in Oaxaca. Although challenges remain, ATBC 2025 illustrated the evolving role of ATBC conferences as platforms for integrative, action‐oriented science to advance conservation and sustainability in the tropics.
