Related Papers
Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology
Vincent Vos
In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary ...
bioRxiv
The Maximum Entropy Formalism of statistical mechanics in a biological application: a quantitative analysis of tropical forest ecology
2021 •
Marcelo Pansonato
In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain almost ten times more of local relative abundances then constraints based on either directional or stabilizing selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale dat...
Minding The Gap: Range Size And Economic Use Drive Functional Trait Data Shortfall In The Atlantic Forest
2020 •
Ênio Sosinski
ABSTRACTBiodiversity shortfalls are knowledge gaps that may result from uneven sampling through time and space and human interest biases. Gaps in data of functional traits of species may add uncertainty in functional diversity and structure measures and hinder inference on ecosystem functioning and ecosystem services, with negative implications for conservation and restoration practices, such as in Atlantic Forest hotspot. Here we investigate which are the potential drivers of trait data gaps and where geographically they are in the Atlantic Forest. We quantified trait gaps for four key plant functional traits of 2335 trees species, and evaluated which factors drive trait gap at the species and at the geographical level. At the species level, we found larger trait gaps for small-ranged and with no economic use. At the geographical level, we found larger gaps at the Atlantic Forest east coast. Trait gaps were higher away from urban areas, and among species with smaller mean range siz...
From plant populations to communities: using hierarchical trait environment relationships to reveal within ecosystem filtering
Vincent Maire
Explaining the existence of highly diverse plant communities under strong abiotic filtering is a long-standing challenge in ecology. Hierarchical aspects of abiotic and biotic filters are rarely taken into account and studies focus mainly on community-level aggregated patterns. Because variations in biotic conditions might take place in short abiotic gradient and within the tolerance of species in regional pool, it is likely that biotic filtering will select individuals within species and adjust population characteristics. To challenge this idea, we replicated a diversity gradient in four highly contrasted wetlands with an almost complete species turn-over, sampling individuals in communities irrespective of their taxonomic identities or status. Using hierarchical distributional modelling, we analyzed the variation of the mean and dispersion of functional trait space at the ecosystem, community and species level. We found that the abiotic differences between ecosystems filtered spec...
Unravelling associations between tree seedling performance, herbivory, competition, and facilitation in high nature value farmlands
Maria Caldeira
Herbivory, plant facilitation, and competition have complex impacts on tree regeneration which are seldom investigated together. Grazing exclosure experiments have allowed to quantify the effects of large herbivores on tree regeneration dynamics but have often ignored the effect of herbivorous insects. We experimentally tested how folivory (percentage of leaf damaged by insects), and microenvironment (tree canopy cover and herbs) jointly alter performance (growth and survival) of seedlings of two dominant Mediterranean oak species within ungulate exclosures. An agroforestry system dominated by cork oak (Quercus suber) and holm oak (Q. rotundifolia) was assessed in south east Portugal. We aimed also to determine whether the two oak species differ in the interdependences between folivory, microenvironment, covaring factors, and seedling performance. Unexpectedly, under the low to moderate insect defoliation occurred in our 3 year field study, growth and survival of cork and holm oak s...
Auxin-driven ecophysiological diversification of leaves in domesticated tomato
2021 •
Luan Rosa
Heterobaric leaves have bundle sheath extensions (BSEs) that compartmentalise the parenchyma, whereas hom*obaric leaves do not. The presence of BSEs affects leaf hydraulics and photosynthetic rate. The tomato (Solanum lycopersicum) obscuravenosa (obv) mutant lacks BSEs. Here we identify the obv gene and the causative mutation, a non-synonymous amino acid change that disrupts a C2H2 zinc finger motif in a putative transcription factor. This mutation exists as a rare polymorphism in the natural range of wild tomatoes, but has increased in frequency in domesticated tomatoes, suggesting that the latter diversified into heterobaric and hom*obaric leaf types. The obv mutant displays reduced vein density, leaf hydraulic conductance and photosynthetic assimilation rate. We show that these and other effects on plant development, including changes in leaf insertion angle, leaf margin serration, minor vein density and fruit shape, are controlled by OBV via changes in auxin signalling. Loss of fu...
Trait variation between and within Andes and coastal mountain ranges in the iconic South American tree Araucaria araucana in Chile
2022 •
Jorge Veloso González
As global commitments to restoration are underway, science is needed to support capacity to achieve meaningful gains for ecosystems and human communities. In Chile, identification and generation of appropriate plant material is a barrier to achieving major restoration goals under the Paris Climate Agreement. Understanding genetic differentiation among plant populations is needed to maximize restoration success. For Araucaria araucana, a highly threatened iconic South American tree, this information is greatly needed to guide restoration and conservation efforts because this species occurs across a strong climate gradient. We grew seedlings from 12 populations of A. araucana across its range in Chile in a common garden to assess regional (coastal versus Andes mountain ranges) and population variation in key plant traits and relate this variation to environmental variables. We demonstrate that A. araucana is differentiated within regions and populations across its range in Chile by a ...
Evidence for alternate stable states in an Ecuadorian Andean Cloud Forest
2021 •
Mika Peck
We analyzed a set of historical data from rapid vegetation inventories in a tropical montane cloud forest in northern Andean Ecuador. Trees in plots from several types of forest were counted and measured, including: (1) primary forest, including mature and recently closed-canopy sites and naturally formed gaps, (2) abandoned pasture, and (3) abandoned, intensively-farmed sites. The goal of the study was to understand in a specific period of time the similarities and differences among natural and anthropogenic disturbances and their potential long term effect on the forest plant community. We found that mature and intermediate close canopy sites are similar. Primary forest sites were observed as resilient to gap-forming disturbances: naturally-formed gaps are quickly colonized by old-forest-associated plant species, and return to an old-forest-type community of trees in a short time. In contrast, forests regenerating from anthropogenic disturbance appear to have multiple possible sta...
bioRxiv (Cold Spring Harbor Laboratory)
Exploring the role of abiotic factors on the seedling recruitment of three plant species in the Colombian Amazon
2022 •
Pablo Stevenson
Drivers of plant traits and forest functional composition in coastal plant communities of the Atlantic Forest
Camilla Rozindo Dias Milanez
The severe deforestation of Brazil's Atlantic Forest and increasing effects of climate change underscore the need to understand how tree species respond to climate and soil drivers. We studied 42 plots of coastal restinga forest, which is highly diverse and spans strong environmental gradients. We determined the forest physiognomy and functional composition, which are physical properties of a community that respond to climate and soil properties, to elucidate which factors drive community-level traits. To identify the most important environmental drivers of coastal Atlantic forest functional composition, we performed a forest inventory of all plants of diameter 5 cm and above. We collected wood samples and leaves from ~85% of the most abundant plant species and estimated height, aboveground biomass (AGB), and basal area of individual plants, and the community-weighted specific leaf area (SLA). In addition to plant traits, we measured water table depth and 25 physicochemical soil...
