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1. Forest type and leaf habit mediate thermal and drought tolerance across a tropical elevational gradient

   https://doi.org/10.1111/1365-2435.70328  

   Terry, Caitlin N; Ortiz‐Colín, Perla; Powers, Jennifer S; Vargas_G, German; Guadamúz, Adrián; Hulshof, Catherine M (June 2026, Functional Ecology)

   Abstract Understanding how local climate patterns select for thermal and drought tolerance traits is needed to predict differential responses to climate change across complex ecosystems. Here, we used high‐throughput methods to measure traits that confer heat and drought tolerance across a tropical climatic variability gradient and examined how forest type and leaf habit mediate these traits.We estimated thermotolerance thresholds (Tcrit, T50, T95), drought tolerance traits (water potential at turgor loss point [𝝭_TLP] and osmotic potential [𝞹_osm]), and morphological traits (wood density and leaf mass per area [LMA]) for 92 woody plant species across six sites along a tropical dry‐to‐wet gradient in Área de Conservación Guanacaste, Costa Rica.Among evergreen species, T95 weakly declined with elevation, LMA was positively associated with T50 and T95, and greater drought tolerance values were found at lower elevations and with greater wood density. Among deciduous species, no significant associations were found between tolerance traits and elevation or wood density, though LMA was positively associated with T50.T95 was higher on average among seasonal dry and ecotonal forest species compared with wet forest species. Additionally, evergreen species from dry and ecotonal forests exhibited greater drought tolerance than those from wet forests, whereas drought tolerance indices did not differ among deciduous species across forest types. These results point to multiple adaptive pathways for evergreen species and provide evidence that evergreen trees face greater drought‐induced selection pressure.Surprisingly, thermal tolerance traits were largely decoupled with drought tolerance traits, suggesting that coordination among traits that confer tolerance to environmental stressors is not generalizable in tropical forests. Read the freePlain Language Summaryfor this article on the Journal blog. 

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2. Forest composition and diversity buffer microclimates and enhance productivity

   https://doi.org/10.1111/1365-2745.70347  

   Park, Maria H; Guzmán_Q, J Antonio; Dyalsingh, Hannah; Scott, Allison; Cavender‐Bares, Jeannine (May 2026, Journal of Ecology)

   Abstract Tree diversity may play a role in buffering forest ecosystems against climate extremes. We asked how diverse tree communities could (1) influence local atmospheric water demand, and (2) how changes in microclimate could be linked to the productivity of trees within forest communities.To assess forest canopy characteristics and calculate above‐ground productivity, we measured plant fractional cover using UAV‐LiDAR and conducted growth inventories in 148 forest plots of a young temperate tree diversity experiment. We monitored the microclimate and tracked soil moisture in a subset of forest plots to understand the relative influence of above‐ground and below‐ground water status on tree growth. Gas exchange, spectral reflectance and leaf mass per area were measured on four tree species distributed throughout the experiment to assess the influence of microclimate on tree physiology.We found that fast‐growing, early successional tree species increased forest cover, which was linked to buffered daily amplitudes of vapour pressure deficits (VPD) within forest plots and increases in the annual wood production of slower‐growing, shade‐tolerant tree species. In assemblages with more buffered microclimates, several slower‐growing tree species showed increased leaf water content and reduced physiological stress. Plots with reduced amplitude in VPD exhibited greater complementarity and productivity relative to those with higher variability.Synthesis. Our findings show that tree diversity and the proportion of fast‐growing, early successional tree species can increase canopy cover and buffer the microclimates of young forests, benefiting the physiology and productivity of slower‐growing, shade tolerant tree species. We reason that a self‐reinforcing dynamic of tree growth and microclimate buffering is likely at play. In the context of a rapidly changing climate, our findings suggest that diverse forest communities can shape local microenvironments to support sustainable ecosystem functioning. 

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3. Reaching new heights: Arboreal ant diversity in a North American temperate forest ecosystem

   https://doi.org/10.1111/icad.12788  

   Kirchner, Michelle; Sorenson, Clyde; Blaimer, Bonnie B; Youngsteadt, Elsa (November 2024, Insect Conservation and Diversity)

   Abstract Most canopy insect research takes place in tropical forests, where communities are highly vertically stratified. However, temperate forest canopies also provide critical resources to many species and are under intense pressure from global change drivers. The relative lack of knowledge regarding temperate canopy insect ecology impedes our forest management and conservation decisions such that we may be losing temperate canopy biodiversity before we know it exists.We directly compared ant diversity and community composition on the ground and in the tree canopy of North American temperate deciduous forests for the first time. We also evaluated two canopy sampling methods—baits and hand collections.We collected 34 ant species from 102 trees across seven sites. Ant diversity was greater on the ground than in the canopy, and species turnover created distinct communities across vertical strata. Only 12% of species were exclusively arboreal, but 47% were collected in both strata, indicating the canopy is an important resource for temperate ants, even if they are not restricted there.Baiting and hand‐collecting recovered similar species richness, but whether baits captured a subset of hand‐collected species or a unique assemblage was site‐dependent. Nevertheless, we suggest that these methods are most effective in conjunction.Hand collection allowed us to document arboreal nests of 10 species, including the invasive needle ant,Brachyponera chinensis, which was previously thought to be strictly terrestrial.Our results emphasise the importance of including the canopy in temperate forest ecology and conservation assessments. 

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4. Shifts in wood anatomical traits after a major hurricane

   https://doi.org/10.1111/1365-2435.14451  

   Ziemińska, Kasia; Bibbo, Silvia; Farrar, Samuel; Thompson, Jill; Uriarte, María; Ziaco, Emanuele; Zimmerman, Jess K.; Muscarella, Robert (December 2023, Functional Ecology)

   Abstract Trait variation across individuals and species influences the resistance and resilience of ecosystems to disturbance, and the ability of individuals to capitalize on postdisturbance conditions. In trees, the anatomical structure of xylem directly affects plant function and, consequently, it is a valuable lens through which to understand resistance and resilience to disturbance.To determine how hurricanes affect wood anatomy of tropical trees, we characterized a set of anatomical traits in wood produced before and after a major hurricane for 65 individuals of 10 Puerto Rican tree species. We quantified variation at different scales (among and within species, and within individuals) and determined trait shifts between the pre‐ and posthurricane periods. We also assessed correlations between traits and growth rates.While the majority of anatomical trait variation occurred among species, we also observed substantial variation within species and individuals. Within individuals, we found significant shifts for some traits that generally reflected increased hydraulic conductivity in the posthurricane period. We found weak evidence for an association between individual xylem anatomical traits and diameter growth rates.Ultimately, within‐individual variation of xylem anatomical traits observed in our study could be related to posthurricane recovery and overall growth (e.g. canopy filling). Other factors, however, likely decouple a relationship between xylem anatomy and diameter growth. While adjustments of wood anatomy may enable individual trees to capitalize on favourable postdisturbance conditions, these may also influence their future responses or vulnerability to subsequent disturbances. Read the freePlain Language Summaryfor this article on the Journal blog. 

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5. Mangrove Damage, Delayed Mortality, and Early Recovery Following Hurricane Irma at Two Landfall Sites in Southwest Florida, USA

   https://doi.org/10.1007/s12237-019-00564-8  

   Radabaugh, Kara R.; Moyer, Ryan P.; Chappel, Amanda R.; Dontis, Emma E.; Russo, Christine E.; Joyse, Kristen M.; Bownik, Melissa W.; Goeckner, Audrey H.; Khan, Nicole S. (April 2019, Estuaries and Coasts)

   Mangrove forests along the coastlines of the tropical and sub-tropical western Atlantic are intermittently impacted by hurricanes and can be damaged by high-speed winds, high-energy storm surges, and storm surge sediment deposits that suffocate tree roots. This study quantified trends in damage, delayed mortality, and early signs of below- and aboveground recovery in mangrove forests in the Lower Florida Keys and Ten Thousand Islands following direct hits by Hurricane Irma in September 2017. Mangrove trees suffered 19% mortality at sites in the Lower Florida Keys and 11% in the Ten Thousand Islands 2–3 months post-storm; 9 months post-storm, mortality in these locations increased to 36% and 20%, respectively. Delayed mortality of mangrove trees was associated with the presence of a carbonate mud storm surge deposit on the forest floor. Mortality and severe branch damage were more common for mangrove trees than for mangrove saplings. Canopy coverage increased from 40% cover 1–2 months post-storm to 60% cover 3–6 months post-storm. Canopy coverage remained the same 9 months post-storm, providing light to an understory of predominantly Rhizophora mangle (red mangrove) seedlings. Soil shear strength was higher in the Lower Florida Keys and varied with depth; no significant trends were found in shear strength between fringe or basin plots. Rates of root growth, as assessed using root in-growth bags, were relatively low at 0.01–11.0 g m−2 month−1 and were higher in the Ten Thousand Islands. This study demonstrated that significant delayed mangrove mortality can occur 3–9 months after a hurricane has passed, with some mortality attributable to smothering by storm surge deposits. 

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