scholarly journals Responses of functional traits in cavity-nesting birds to logging in subtropical and temperate forests of the Americas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alejandro A. Schaaf ◽  
Daniela Gomez ◽  
Ever Tallei ◽  
Constanza G. Vivanco ◽  
Román A. Ruggera
Keyword(s):  
Functional Traits ◽  
Temperate Forests ◽  
Functional Divergence ◽  
Ecosystem Functions ◽  
Functional Changes ◽  
Point Counts ◽  
Cavity Nesting ◽  
Functional Richness ◽  
Bird Richness ◽  
Species Richness And Abundance

AbstractLogging causes changes in habitat structure, which can potentially lead to variations in taxonomic and functional richness of biodiversity. Studies on how functional traits in birds are affected by logging operations can provide an important element for the understanding of ecosystem processes. In this paper, we examined how logging in subtropical Andean forests influenced taxonomic and functional diversity of cavity-nesting birds. We used these results to compare how logging affected ecosystem functions in temperate and subtropical forests of the Americas. We used point-counts to examine the effects of logging on taxonomic and functional traits in avian communities (Functional Richness, Functional evenness, Functional Divergence, and Community-weighted mean). We found that logging changed bird richness and abundance, although it had no effect on the functional response to the measured traits. The comparison of our results with those of temperate forests of Canada and Chile reveals differences in the functional richness of birds in these habitats, with a lower impact of logging on functional traits. We highlight the importance of including functional traits in the analyses, since the reduction in the species richness and abundance may not be translated into functional changes within the ecosystem.

scholarly journals Functional Traits on Cavity-nesting Birds in Subtropical Andean Forest: Response to Logging Activity and Comparing with American Temperate Forests

2021 ◽  
Author(s):  
Alejandro A. Schaaf ◽  
Daniela Gomez ◽  
Ever Tallei ◽  
Constanza G. Vivanco ◽  
Román A. Ruggera
Keyword(s):  
Functional Traits ◽  
Temperate Forests ◽  
Functional Divergence ◽  
Functional Changes ◽  
Point Counts ◽  
Cavity Nesting ◽  
Functional Richness ◽  
Bird Richness ◽  
Community Weighted Mean ◽  
Species Richness And Abundance

Abstract Logging causes changes in habitat structure, which can potentially lead to variations in taxonomic and functional richness of biodiversity. In this paper, we examined how logging in subtropical Andean forests has influenced taxonomic and functional diversity of cavity-nesting birds. We used point-counts to examine the effects of logging on taxonomic and functional traits of avian communities (Functional Richness, Functional evenness, Functional Divergence, and Community-weighted mean). We found that logging changes bird richness and abundance, although it had no effect on the functional response to the measured traits. The comparison of our results with those of temperate forests of Canada and Chile reveals differences in the functional richness, with a lower impact of logging on functional traits. We highlight the importance of including functional traits in the analyses, since the reduction in the species richness and abundance may not translate into functional changes within the ecosystem.

Remotely sensed habitat variables are poor surrogates for functional traits of rocky reef fish assemblages

2016 ◽  
Vol 43 (4) ◽  
pp. 368-375 ◽  
Author(s):  
MELINDA A. COLEMAN ◽  
TIM INGLETON ◽  
RUSSELL B. MILLAR ◽  
PETER L. DAVIES ◽  
ALAN JORDAN ◽  
...  
Keyword(s):  
Species Richness ◽  
Functional Traits ◽  
Conservation Planning ◽  
Fish Assemblages ◽  
Remotely Sensed ◽  
Biological Data ◽  
Rocky Reef ◽  
Physical Habitat ◽  
Functional Richness ◽  
Species Richness And Abundance

SUMMARYConservation planning often relies on measures such as species richness and abundance to prioritize areas for protection. Nonetheless, alternative metrics such as functional traits have recently been shown to be useful complementary measures for detecting biological change. Timely conservation planning often precludes the collection of such detailed biological data relying instead on remotely-sensed habitat mapping as a surrogate for diversity. While there is evidence that habitat maps may predict taxonomic species richness and diversity in some coastal ecosystems, it is unknown whether similar strong relationships exist for functional traits and functional multimetrics. We compared the performance of physical habitat structural complexity obtained from high definition swath mapping in explaining variation in traditional taxonomic metrics as well as functional traits (e.g., maximum length, trophic level, gregariousness) and functional multimetrics (e.g., functional richness, dispersion) of fish assemblages. Reef complexity measures were good surrogates for fish species richness and abundance but not for functional traits or multimetrics, except functional richness at the scale of 1 m. Remotely sensed habitat maps may not be a good surrogate for predicting functional traits and multimetrics of fish assemblages, and must be used with caution when maximizing such aspects of assemblages is a priority for conservation planning.

scholarly journals Functional Divergence between Várzea and Igapó Forests: A Study of Functional Trait Diversity in the Colombian Orinoco Basin

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1172
Author(s):  
Diana Bonilla ◽  
Ana M. Aldana ◽  
Sasha Cárdenas ◽  
Adriana Sanchez
Keyword(s):  
Plant Species ◽  
Functional Diversity ◽  
Functional Traits ◽  
Community Assembly ◽  
Forest Type ◽  
Functional Divergence ◽  
Dry Matter Content ◽  
Functional Richness ◽  
Flooded Forests ◽  
The Impact

Research Highlights: Functional diversity studies help to better understand how organisms respond to different environmental conditions. Conditions in tropical flooded forests are highly variable, including levels of nutrient availability, pH, and flood depth, but few studies have explored the impact of variation in these factors on plant functional diversity. Background and Objectives: In the Orinoco basin, as in the Amazon, floodplain forests have been classified into várzea (white-water rivers, with nutrient-rich soils) and igapó (black-water rivers, associated with nutrient-poor soils). We evaluated the functional diversity of plant species in várzea and igapó, as well as the influence of external and internal filters on the plant community assembly of each forest type, and compared our results with studies in the Amazon basin. Materials and Methods: Six functional traits were recorded in the várzea and igapó forests of the Colombian Orinoco basin (one-hectare plot for each forest type, with no replicates). We evaluated plant species diversity (richness, Fisher’s α, Shannon and Simpson indices), as well as functional diversity (functional richness, functional evenness, functional divergence, and functional dispersion) and the influence of external and internal filters, based on a comparison of variance at different organizational levels. Results: A high functional differentiation between várzea and igapó was found, as well as a high functional divergence within each forest type. We also observed a greater influence of internal filters on the community assembly of both forest types, compared to external filters. Functional traits such as wood density and leaf dry matter content, showed the same patterns as the várzea and igapó forests in the Amazon. Conclusions: Despite the low taxonomic and functional richness, there is high functional divergence within flooded forests. We also show that in forests under stress (e.g., from flooding), internal filters can be key in assembling communities and promote high functional divergence. Given that the functional diversity of the várzea and igapó in the Orinoco is largely unexplored, we highlight the need for more research for the effective conservation of these flooded forests.

scholarly journals A research framework for projecting ecosystem change in highly diverse tropical mountain ecosystems

Oecologia ◽  
2021 ◽  
Author(s):  
Jörg Bendix ◽  
Nicolay Aguire ◽  
Erwin Beck ◽  
Achim Bräuning ◽  
Roland Brandl ◽  
...  
Keyword(s):  
Land Use ◽  
Functional Traits ◽  
Biomass Production ◽  
Environmental Changes ◽  
Ecosystem Functions ◽  
Ecosystem Change ◽  
Mountain Ecosystems ◽  
Abiotic Conditions ◽  
Research Framework ◽  
Tropical Mountain

AbstractTropical mountain ecosystems are threatened by climate and land-use changes. Their diversity and complexity make projections how they respond to environmental changes challenging. A suitable way are trait-based approaches, by distinguishing between response traits that determine the resistance of species to environmental changes and effect traits that are relevant for species' interactions, biotic processes, and ecosystem functions. The combination of those approaches with land surface models (LSM) linking the functional community composition to ecosystem functions provides new ways to project the response of ecosystems to environmental changes. With the interdisciplinary project RESPECT, we propose a research framework that uses a trait-based response-effect-framework (REF) to quantify relationships between abiotic conditions, the diversity of functional traits in communities, and associated biotic processes, informing a biodiversity-LSM. We apply the framework to a megadiverse tropical mountain forest. We use a plot design along an elevation and a land-use gradient to collect data on abiotic drivers, functional traits, and biotic processes. We integrate these data to build the biodiversity-LSM and illustrate how to test the model. REF results show that aboveground biomass production is not directly related to changing climatic conditions, but indirectly through associated changes in functional traits. Herbivory is directly related to changing abiotic conditions. The biodiversity-LSM informed by local functional trait and soil data improved the simulation of biomass production substantially. We conclude that local data, also derived from previous projects (platform Ecuador), are key elements of the research framework. We specify essential datasets to apply this framework to other mountain ecosystems.

scholarly journals Canopy Leaf Traits, Basal Area, and Age Predict Functional Patterns of Regenerating Communities in Secondary Subtropical Forests

2021 ◽  
Vol 4 ◽  
Author(s):  
Sandra Cristina Müller ◽  
Rodrigo Scarton Bergamin ◽  
Kauane Maiara Bordin ◽  
Joice Klipel ◽  
Milena Fermina Rosenfield
Keyword(s):  
Functional Diversity ◽  
Functional Traits ◽  
Natural Regeneration ◽  
Basal Area ◽  
Leaf Traits ◽  
Leaf Nitrogen ◽  
Ecosystem Functions ◽  
Secondary Forests ◽  
Functional Composition ◽  
Forest Age

Secondary forests originate from natural regeneration after fallow (succession) or restoration. Species assembly in these communities, which can affect ecosystem functions and successional trajectories, is very unpredictable. Trait-based trajectories can shed light on the recovery of ecosystem functions and enable predictions of how the regenerating communities will change with forest age. Regeneration communities are affected by initial conditions and also by canopy structure and functional traits that alter dispersers' attractiveness and coexistence mechanisms. Here we evaluated how community functional traits change over time and tested if functional diversity and composition of the established canopy, as well as the structure of the canopy and forest age, influence the functional structure of regenerating tree communities when compared to their reference forests. For this, we calculated dissimilarity in trait composition (community-weighted means) and in functional diversity of regenerating communities of each succession/restoration stand, using the tree stratum of nearby mature forests as baseline values. Functional trait information comprises leaf, wood density, and reproductive traits from tree species. Our community data contain information from natural successional forests and restoration sites, in the South-Brazilian Atlantic Forest. Predictor variables of functional dissimilarities were forest age, canopy structural variables, canopy functional composition, and functional diversity. Results showed leaf traits (leaf dry matter content, leaf nitrogen content, leaf nitrogen-phosphorus ratio) and seed mass varying with forest age. Canopy functional composition based on leaf traits and total basal area significantly predicted multiple trait functional dissimilarity between the regeneration component of secondary forests and their reference community values. Dissimilarity increased when the canopy was composed of species with more acquisitive traits. Difference in functional diversity was only influenced by forest age. Mid-stage secondary forests showed lower functional diversity than early-stage forests. Our results indicated the importance of canopy traits on the natural regeneration of secondary subtropical forests. If functional similarity with reference forests is a desired objective in order to recover ecosystem functions through natural regeneration, leaf functional traits of canopy trees that establish or are planted in degraded areas must be considered in the successional processes.

scholarly journals Functional divergence of bitter taste receptors in a nectar-feeding bird

2019 ◽  
Vol 15 (9) ◽  
pp. 20190461 ◽  
Author(s):  
Yi Wang ◽  
Hengwu Jiao ◽  
Peihua Jiang ◽  
Huabin Zhao
Keyword(s):  
Secondary Metabolites ◽  
Bitter Taste ◽  
Functional Divergence ◽  
Taste Receptor ◽  
Bitter Taste Receptor ◽  
Functional Changes ◽  
Nectar Feeding ◽  
Gene Copies ◽  
Plant Pollinator ◽  
Higher Sensitivity

Nectar may contain many secondary metabolites that are commonly toxic and bitter-tasting. It has been hypothesized that such bitter-tasting secondary metabolites might keep the nectar exclusive to only a few pollinators. To test this hypothesis, we examined functional changes of bitter taste receptor genes ( Tas2r s) in a species of nectar-feeding bird (Anna's hummingbird) by comparing these genes with those from two closely related insect-feeding species (chimney swift and chuck-will's widow). We previously identified a larger number of Tas2r s in the hummingbird than in its close insectivorous relatives. In the present study, we demonstrate higher sensitivity and new functions in the hummingbird Tas2r gene copies generated by a lineage-specific duplication, which has been shaped by positive selection. These results suggest that the bitter taste may lead to increased sensitivities and specialized abilities of the hummingbird to detect bitter-tasting nectar. Moreover, this study potentially supports the hypothesis that bitter-tasting nectar may have been specialized for some pollinators, thus enforcing plant–pollinator mutualism.

Mechanisms regulating spatial changes in grassland productivity following nutrient addition in northern China

2019 ◽  
Vol 41 (1) ◽  
pp. 83
Author(s):  
Na Zhao ◽  
Xinqing Shao ◽  
Chao Chen ◽  
Jiangwen Fan ◽  
Kun Wang
Keyword(s):  
Functional Traits ◽  
Plant Biomass ◽  
Northern China ◽  
Functional Trait ◽  
Community Response ◽  
Nutrient Addition ◽  
Leymus Chinensis ◽  
Ecosystem Functions ◽  
Natural Grasslands ◽  
Key Species

Plant biomass is the most fundamental component of ecosystems. The spatial stability of plant biomass is important, and the mechanisms regulating plant biomass spatial variability in variable environments are a central focus of ecology. However, they have rarely been explored. We conducted an experiment to test how diversity and functional traits affected variation in biomass and community response to nutrient availability in three plant communities: natural; forb, legume, and bunchgrass; and rhizomatous grass. We found that biomass stability rarely changed with increasing taxonomic species richness and functional group richness but declined with increasing Shannon–Weiner indices (the combination of richness and evenness) and functional trait diversity. However, differences in plant species composition generated different responses in both the amount and spatial variation of biomass following nutrient addition. Because rhizomatous grasses are weakly competitive in nutrient-poor conditions, interaction between resource-acquisitive (grass) and stress-tolerant (forb) species in the natural community conferred the greatest overall stability. The rapid nutrient acquisition ability of the rhizomatous grass Leymus chinensis was stimulated in nutrient-abundant conditions. The functional traits of this dominant species overrode the diversity interaction effects of the natural and forb, legume, and bunchgrass communities. This ultimately resulted in the rhizomatous grass community being the most stable. Community stability was strongly determined by a few key species, particularly rhizomatous grasses, rather than by the average response of all species, thereby supporting the mass ratio hypothesis. Our results indicated that rhizomatous grasses could provide vegetative productivity to reduce soil loss and prevent degradation of L. chinensis-dominant grassland. Thus, protecting specific species is critical for maintaining rangeland ecosystem functions. Moreover, the conservation importance of grasses, non-leguminous forbs, legumes, or even rare species could not be ignored. Maintaining stability mechanisms in natural grasslands is complex, and therefore, further studies need to focus on finding a unified mechanism that can regulate appreciable biomass variation under shifting environmental conditions.

scholarly journals The costs of ignoring species detectability on functional diversity estimation

The Auk ◽  
2020 ◽  
Vol 137 (4) ◽  
Author(s):  
Facundo Xavier Palacio ◽  
René E Maragliano ◽  
Diego Montalti
Keyword(s):  
Functional Diversity ◽  
Functional Divergence ◽  
Habitat Type ◽  
Species Traits ◽  
Bird Communities ◽  
Imperfect Detection ◽  
East Central ◽  
Functional Types ◽  
Functional Richness ◽  
Species Occupancy

Abstract Functional diversity (FD) approaches have been increasingly used to understand ecosystem functioning in bird communities. These approaches typically rely on the assumption that species are perfectly detected in the field, despite the fact that imperfect detection represents a ubiquitous source of bias in biodiversity studies. This may be notably important in FD studies, because detection may depend on the functional traits used to compute FD metrics. However, little effort has been devoted to account for imperfect detection in FD studies, and therefore the degree to which species traits and detectability affects FD remains poorly understood. We predict that observed FD metrics may either underestimate or overestimate detection-corrected FD, because FD has multiple independent dimensions with different data properties. We assessed whether detection was related to bird traits (body mass, diet, and foraging stratum), accounting for habitat type, season, and phylogeny. We then used a multi-species occupancy model to obtain detection-corrected FD metrics (functional richness [FRic], functional evenness [FEve], and functional divergence [FDiv]), and compared observed and detection-corrected FD estimates in bird communities from east-central Argentina. Some functional types of birds (raptors and insectivores) were more easily overlooked, whereas others (seed and leaf eaters) were more easily detected. Some observed FD metrics underestimated detection-corrected FD (FRic and FDiv), whereas some others (FEve) overestimated detection-corrected FD. Both observed and detection-corrected FRic revealed differences between seasons, but not between habitat types. However, detection-corrected FEve and FDiv showed differences between seasons, contrary to observed estimates. Our results indicate that failure to account for unequal ease of detecting species can lead to erroneous estimates of FD because some functional types of birds are more easily overlooked. We outline some guidelines to help ornithologists identifying under which circumstances detection may be a concern and warn against the indiscriminate use of FD metrics without accounting for species detection.

scholarly journals Composition of Cavity-Nesting Bird Communities in Montane Aspen Woodland Fragments: The Roles of Landscape Context and Forest Structure

The Condor ◽  
2002 ◽  
Vol 104 (4) ◽  
pp. 890-896 ◽  
Author(s):  
Joshua J. Lawler ◽  
Thomas C. Edwards
Keyword(s):  
Populus Tremuloides ◽  
Bird Communities ◽  
Landscape Context ◽  
Glaucomys Sabrinus ◽  
Northern Flying Squirrel ◽  
Nest Boxes ◽  
Cavity Nesters ◽  
Cavity Nesting ◽  
Structure Tree ◽  
Species Richness And Abundance

Abstract We compared cavity-nesting bird communities in aspen (Populus tremuloides) woodland fragments classified on the basis of vegetation structure (tree density) and landscape context (surrounding vegetation). We found very few cavity nesters in fragments predominantly surrounded by forests. Fragments adjacent to meadows contained more species and a greater abundance of cavity nesters. Species richness and abundance were higher in sparsely than in densely treed meadow fragments. Because secondary cavity nesters are often limited by cavity availability, we augmented natural cavities with nest boxes. Although only five boxes contained bird nests, these were all in sparse aspen fragments predominantly surrounded by meadows. However, we found 25 northern flying squirrel (Glaucomys sabrinus) nests in boxes, none of which were in sparse meadow fragments. In addition to highlighting the importance of landscape context in avian and mammalian habitat relationships, our results suggest that predator or competitor interactions may help structure this cavity-nester community. Composición de las Comunidades de Aves que Nidifican en Cavidades en los Fragmentos de Bosque Montano de Álamo: El Papel del Contexto del Paisaje y la Estructura del Bosque Resumen. Comparamos comunidades de aves que nidifican en cavidades en fragmentos de bosque de álamo (Populus tremuloides) clasificados en base a la estructura de la vegetación (densidad de árboles) y al contexto del paisaje (vegetación circundante). Encontramos muy pocas aves que nidifican en cavidades en los fragmentos rodeados predominantemente por bosque. Los fragmentos adyacentes a prados presentaron más especies y mayor abundancia de aves. La riqueza y la abundancia de especies fueron mayores en fragmentos con baja densidad de árboles que estuvieron rodeados por prados. Debido a que las aves que nidifican en cavidades secundarias están a menudo limitadas por la disponibilidad de cavidades, aumentamos las cavidades naturales con cajas de anidaje. Aunque solamente cinco cajas contuvieron nidos de aves, éstas estuvieron todas en los fragmentos con baja densidad de álamos rodeados predominantemente por prados. Sin embargo, encontramos 25 nidos de ardillas voladoras norteñas (Glaucomys sabrinus) en las cajas de anidaje, de las cuales ninguna estuvo en fragmentos con baja densidad de árboles rodeados por prado. Nuestros resultados destacan la importancia del contexto del paisaje en las relaciones entre el hábitat y las aves y mamíferos, y sugieren que las interacciones con depredadores o competidores pueden influenciar la estructura de la comunidades de aves que anidan en cavidades.

scholarly journals Treeline ecotones shape the distribution of avian species richness and functional diversity in south temperate mountains

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tomás A. Altamirano ◽  
Devin R. de Zwaan ◽  
José Tomás Ibarra ◽  
Scott Wilson ◽  
Kathy Martin
Keyword(s):  
Species Richness ◽  
Functional Diversity ◽  
Functional Traits ◽  
Habitat Structure ◽  
Environmental Gradients ◽  
Montane Forest ◽  
Avian Species ◽  
Point Counts ◽  
Mountain Habitats ◽  
Elevational Range

Abstract Mountains produce distinct environmental gradients that may constrain or facilitate both the presence of avian species and/or specific combinations of functional traits. We addressed species richness and functional diversity to understand the relative importance of habitat structure and elevation in shaping avian diversity patterns in the south temperate Andes, Chile. During 2010–2018, we conducted 2202 point-counts in four mountain habitats (successional montane forest, old-growth montane forest, subalpine, and alpine) from 211 to 1,768 m in elevation and assembled trait data associated with resource use for each species to estimate species richness and functional diversity and turnover. We detected 74 species. Alpine specialists included 16 species (22%) occurring only above treeline with a mean elevational range of 298 m, while bird communities below treeline (78%) occupied a mean elevational range of 1,081 m. Treeline was an inflection line, above which species composition changed by 91% and there was a greater turnover in functional traits (2–3 times greater than communities below treeline). Alpine birds were almost exclusively migratory, inhabiting a restricted elevational range, and breeding in rock cavities. We conclude that elevation and habitat heterogeneity structure avian trait distributions and community composition, with a diverse ecotonal sub-alpine and a distinct alpine community.

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