Publications by authors named "Patricia Alvarez-Loayza"

Article Synopsis
  • * Analysis of data from over 1 million forest plots and thousands of tree species shows that wood density varies significantly by latitude, being up to 30% denser in tropical forests compared to boreal forests, and is influenced mainly by temperature and soil moisture.
  • * The research also finds that disturbances like human activity and fire alter wood density at local levels, affecting forest carbon stock estimates by up to 21%, emphasizing the importance of understanding environmental impacts on forest ecosystems.
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Tree growth and longevity trade-offs fundamentally shape the terrestrial carbon balance. Yet, we lack a unified understanding of how such trade-offs vary across the world's forests. By mapping life history traits for a wide range of species across the Americas, we reveal considerable variation in life expectancies from 10 centimeters in diameter (ranging from 1.

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Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system. Remote-sensing estimates to quantify carbon losses from global forests are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced and satellite-derived approaches to evaluate the scale of the global forest carbon potential outside agricultural and urban lands.

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Phenology has long been hypothesized as an avenue for niche partitioning or interspecific facilitation, both promoting species coexistence. Tropical plant communities exhibit striking diversity in reproductive phenology, but many are also noted for large synchronous reproductive events. Here we study whether the phenology of seed fall in such communities is nonrandom, the temporal scales of phenological patterns, and ecological factors that drive reproductive phenology.

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Article Synopsis
  • * Researchers used camera traps to gather a comprehensive data set of 154,123 records from 317 species of mammals, birds, and reptiles across eight Amazonian countries.
  • * This extensive data set facilitates new ecological research on the impacts of habitat loss and climate change in the Amazon, and its use is encouraged with proper citation.
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Purpose: To better understand clinic attendees' perceptions of nonsterile glove (NSG) use during vaccination and their concern for the environment.

Design: This was a cross-sectional, self-administered, in-person survey.

Methods: A nonrandom volunteer sample of vaccination clinic attendees ( = 789) completed a survey assessing their perception of NSG use during influenza vaccination administration and their concern for the environment.

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Article Synopsis
  • The study highlights the uncertainty in how tropical forests' carbon storage responds to climate change, particularly the effects of long-term drying and warming.
  • Analysis of 590 permanent plots across the tropics finds that maximum temperature significantly reduces aboveground biomass, affecting carbon storage more in hotter forests.
  • The results indicate that tropical forests have greater resilience to temperature changes than short-term studies suggest, emphasizing the need for forest protection and climate stabilization for long-term adaptation.
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Carnivores have long been used as model organisms to examine mechanisms that allow coexistence among ecologically similar species. Interactions between carnivores, including competition and predation, comprise important processes regulating local community structure and diversity. We use data from an intensive camera-trapping monitoring program across eight Neotropical forest sites to describe the patterns of spatiotemporal organization of a guild of five sympatric cat species: jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yagouaroundi) and margay (Leopardus wiedii).

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Article Synopsis
  • Monitoring was conducted over 8.4 years across 289 seed traps in an Amazonian floodplain forest, revealing that each 0.5-m site annually receives only three to four species of tree seeds. * The number of seed species arriving at each site increased over time, indicating a random pattern of seed arrival, with yearly captures varying significantly throughout the study period. * Dispersal limitation appears to be a major factor in seed establishment, with over 99% of seeds failing to reach suitable sites, suggesting that understanding larger-scale dispersal processes is crucial for comprehending forest diversity and composition.
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Treefall gaps have long been a central feature of discussions about the maintenance of tree diversity in both temperate and tropical forests. Gaps expose parts of the forest floor to direct sunlight and create a distinctive microenvironment that can favor the recruitment into the community of so-called gap pioneers. This traditional view enjoys strong empirical support, yet has been cast into doubt by a much-cited article claiming that gaps are inherently "neutral" in their contribution to forest dynamics.

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Article Synopsis
  • The study investigates how natural enemies impact plant populations and species coexistence, focusing on two palm species, Attalea phalerata and Astrocaryum murumuru, in Manu National Park, Peru.
  • Researchers conducted seed predation experiments and analyzed the distribution and biomass of the palms to assess Janzen-Connell effects at different life stages.
  • Results showed that the strength of these effects varied: Attalea phalerata had negative effects on seedling recruitment near adult trees, while Astrocaryum murumuru maintained high recruitment, illustrating how phenology and shade tolerance influence these interactions.*
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Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified.

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The biodiversity-productivity relationship (BPR) is foundational to our understanding of the global extinction crisis and its impacts on ecosystem functioning. Understanding BPR is critical for the accurate valuation and effective conservation of biodiversity. Using ground-sourced data from 777,126 permanent plots, spanning 44 countries and most terrestrial biomes, we reveal a globally consistent positive concave-down BPR, showing that continued biodiversity loss would result in an accelerating decline in forest productivity worldwide.

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The conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon stock conservation will provide benefits to biodiversity in part because whether forests that contain high carbon density in their aboveground biomass also contain high animal diversity is unknown. Here, we empirically examined medium to large bodied ground-dwelling mammal and bird (hereafter "wildlife") diversity and carbon stock levels within the tropics using camera trap and vegetation data from a pantropical network of sites.

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Defaunation is causing declines of large-seeded animal-dispersed trees in tropical forests worldwide, but whether and how these declines will affect carbon storage across this biome is unclear. Here we show, using a pan-tropical data set, that simulated declines of large-seeded animal-dispersed trees have contrasting effects on aboveground carbon stocks across Earth's tropical forests. In our simulations, African, American and South Asian forests, which have high proportions of animal-dispersed species, consistently show carbon losses (2-12%), but Southeast Asian and Australian forests, where there are more abiotically dispersed species, show little to no carbon losses or marginal gains (±1%).

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Extinction rates in the Anthropocene are three orders of magnitude higher than background and disproportionately occur in the tropics, home of half the world's species. Despite global efforts to combat tropical species extinctions, lack of high-quality, objective information on tropical biodiversity has hampered quantitative evaluation of conservation strategies. In particular, the scarcity of population-level monitoring in tropical forests has stymied assessment of biodiversity outcomes, such as the status and trends of animal populations in protected areas.

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The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼ 40,000 and ∼ 53,000, i.e.

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While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few 'hyperdominant' species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing and producing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carbon cycling, and whether dominant species are characterized by specific functional traits.

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Tall canopy trees produce many more seeds than do understory treelets, yet, on average, both classes of trees achieve the same lifetime fitness. Using concurrent data on seedfall (8 years) and sapling recruitment (12 years) from a long-established tree plot at the Cocha Cashu Biological Station in Peru, we show that a 40-m canopy tree must produce roughly 13 times the mass of seeds to generate a sapling as a 5-m understory treelet. Mature tree height accounted for 41% of the variance in seed mass per sapling recruit in a simple univariate regression, whereas a multivariate model that included both intrinsic (seed mass, tree height, and dispersal mode) and extrinsic factors (sapling mortality as a surrogate for microsite quality) explained only 31% of the variance in number of seeds per sapling recruit.

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