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We present allometric models for estimating total carbon content and above ground carbon (AGC) for the Arecaceae family, and for seven abundant neotropical palm species: the canopy species Socratea exorrhiza (n = 10) and Iriartea deltoidea (n = 10), the sub-canopy palm Euterpe precatoria (n = 10), and the understory species Asterogyne martiana (n = 15), Prestoea decurrens (n = 10), Geonoma interrupta (n = 10), and Chamaedorea tepejilote (n = 22). Understanding the allometry of functional groups such as palms is critical for improving carbon stocks estimates in tropical forests and determining how allometric differences affect species functional diversity. The research was carried out in the tropical rainforests of the Caribbean slope of Costa Rica. We harvested 87 palms of a wide range of sizes, and separated them into roots, stems, and leaves, measured their fresh and dry biomass, and calculated their carbon content, tissue density, and dry mass fraction (dmf). Our general palm model estimating total carbon content based on these seven species and 87 samples accounted for 92% of the variation across species. We generated a similar model to estimate AGC and explained 91% of the variation. We compared our AGC model with two models used to estimate palm carbon content: Goodman et al. (2013)’s and Chave et al. (2014)’s models and found that all three converged on the estimation of AGC although our model was the most parsimonious because it achieved the same efficiency with only two variables, stem diameter and stem height. To improve the accuracy of allometric models we need to incorporate more species, a greater diversity of growth forms, a wider range of sizes, a larger sample size, and more diversity of habitats dominated by palms. Estimating carbon content using allometric approaches could benefit from more consistency in data collection across plant groups.

We present allometric models to estimate total carbon content and above ground carbon (AGC) for the family Arecaceae, and for 7 abundant neotropical palm species (the canopy species Socratea exorrhiza and Iriartea deltoidea , the sub-canopy palm Euterpe precatoria , and the understory species Asterogyne martiana , Prestoea decurrens , Geonoma interrupta and Chamaedorea tepejilote ). The study was done in the tropical rainforests of the Caribbean slope of Costa Rica. We harvested 87 individuals of a wide range of sizes, and divided them into roots, stems, and leaves, weight their fresh and dry biomass, calculated the carbon content, tissue density, leaf area, and shoot:root ratios (based on biomass and carbon content). The general palm model estimating total carbon content accounted for 92% of the variation and had diameter at breast height, stem height, and dry mass fraction as predictor variables. We generated a similar model to estimate AGC, which included the same variables and explained 91% of the variation. We compared our AGC model with two models used to estimate palm carbon content: Goldman et al. (2013)´s and Chave et al. (2014)´s models and found a range of R 2 values ​​of 0.87 to 0.91. Understory palm allometry was centered around biomass allocation, whereas sub-canopy and canopy species were associated with traits related to palm size (mainly DBH, total height, and leaf area). The efficiency the allometric models depends on species identity, sample size, and size range.

Functional traits are morphological and physiological characteristics that determine growth, reproduction, and survival strategies. The leaf economics spectrum proposes two opposing life history strategies: species with an "acquisitive" strategy grow fast and exploit high-resource environments, while species with a "conservative" strategy emphasize survival and slow growth under low resource conditions. We analyzed interspecific variation in nine functional traits related to biomass allocation and tissue quality in seven Neotropical palm species from three forest strata (understory, subcanopy, and canopy). We expected that the level of resources of a stratum that a species typically exploits would determine the dominance of either the exploitative or conservative strategy, as well as the similarity in functional traits between species. If this is correct, then canopy and subcanopy species will show an acquisitive strategy emphasizing traits targeting a larger size, whereas understory species will show a conservative strategy with traits promoting efficient biomass allocation. Two principal components (57.22% of the variation) separated palm species into: a) canopy and subcanopy species whose traits were congruent with the acquisitive strategy and that emphasized large size (i.e., height, carbon content, and leaf area), and b) understory species whose traits were associated with efficient biomass allocation (i.e., dmf and tissue density). Since palms are one of the most abundant life forms in tropical forests, exploring the variation in functional traits within this group could significantly improve our understanding of plant adaptation to environmental gradients.

Introduction: Medium and large-sized mammals are threatened globally due to habitat loss and fragmentation. In Costa Rica, forest fragments that remain outside protected areas may serve as a refuge or corridor for these animals. Mammal presence in fragmented landscapes may be influenced by resource availability, which varies greatly in seasonal regions. Objective: To determine the species richness of medium and large-sized mammals in a forest fragment, and to examine if species diversity and detectability varied between the wet and dry season. Methods: We established 26 camera trap stations throughout the Municipal Forest of Atenas (Alajuela, Costa Rica), a 26.4 ha forest fragment that provides water to about 1 800 people. From August 2021 to April 2022, one camera trap was active at each station for 12-21 days throughout each season (dry and wet), for a total of 810 camera trap days. We applied rarefaction and extrapolation curves to characterize mammal’s species diversity and compare it between seasons. Results: We detected 19 species of mammals. The most frequently detected species were the White-nosed Coati (Nasua narica; 0.254 detections/camera trap day), and the Central American Agouti (Dasyprocta punctata; 0.163 detections/camera trap day). We also registered four species considered as endangered in Costa Rica, three felines: Puma concolor, Herpailurus yagouaroundi, Leopardus pardalis, and the Neotropical River Otter, Lontra longicaudis. Seasonality did not affect species diversity, but it influenced dominant species and detectability, which was greater during the wet season. Conclusions: Our study demonstrates how protecting small forest fragments, can help conserve endangered medium and large-sized mammals in human-dominated landscapes. Objective: We aimed to determine the species richness of medium and large-sized mammals in a forest fragment protected for water production, and to examine if species diversity and detectability varied between the wet and dry season. Methods: We established 26 camera trap stations throughout the Municipal Forest of Atenas (MFA), a 26-ha forest fragment that provides drinking water to about 1 800 people. From August 2021 to April 2022, one camera trap was active at each station for 12-21 days throughout each season (dry and wet), for a total of 810 camera trap days. We applied rarefaction and extrapolation curves to characterize mammal’s species diversity and compare it between seasons. Results: We detected 19 species of medium and large-sized mammals. The species with the highest frequency of detections were the White-nosed Coati (Nasua narica; 0.504 detections/camera trap day), and the Central American Agouti (Dasyprocta punctata; 0.377 detections/camera trap day). We also detected four species considered as endangered in Costa Rica, three felines: Puma concolor, Herpailurus yagouaroundi, Leopardus pardalis, and the Neotropical River Otter, Lontra longicaudis. Seasonality did not affect species diversity but influenced the detectability of dominant species. Discussion: The relatively high richness of mammals observed in the MFA is likely related to the surrounding land use, which is dominated by agroforestry systems (e. g., coffee plantations) and forest patches, that may contribute to animal mobility and serve as refuge in fragmented landscapes. Conclusions: Our study demonstrates how protecting ecosystem services, such as water, may also help conserving endangered medium and large-sized mammals in fragmented landscapes.