Abundance of epigaeic arthropods in a Brazilian savanna under different fire frequencies

Fire is a major determinant of structure and dynamics in savannas, and the rapid increase of human activities in this biome has changed the natural burning regime. The effects of fire on the fauna of the cerrado (Brazilian savanna) are still poorly understood, and studies comparing sites frequently and infrequently burned are scarce. In this study, the abundance of epigaeic arthropod orders and trophic guilds was assessed in cerrado sites located in the Brazilian Central Plateau that were subjected to three burning frequencies: frequent (HighFi), intermediary (MidFi), and infrequent (LowFi). In general, we found a positive relationship between the abundance of epigaeic arthropods and fire frequency. When arthropods were analyzed by orders, the abundance of Collembola and Orthoptera was lower in the LowFi site, while for Hemiptera, it was higher in the MidFi site. No significant differences were found for Hymenoptera, Coleoptera, and Araneae. The abundance of detritivores and herbivores decreased from HighFi to LowFi, but did not change significantly for omnivores and predators. These results indicate that some arthropod groups may not only be resilient to fire effects, but actually might benefit from fire effects in the cerrado. Characterizing arthropod responses to burning frequency at high taxonomic or functional levels is important for applied studies. Based on the results of the current study, springtails and ants seem to be particularly appropriate focal groups for further exploratory studies on the effects of fire at the species level.71872

High loss of plant phylogenetic and functional diversity due to simulated extinctions of pollinators and seed dispersers in a tropical savanna

Identification of the factors driving extinctions is fundamental to conservation biology. Here, we assessed the likely consequences of extinction of pollinators and dispersers for phylogenetic and functional diversity of savanna woody plant species. Loss of phylogenetic diversity was greater than expected by chance in simulated extinctions of moth- and beetle-pollinated species, and bird- and mammal-dispersed species. In extinction simulations of bee and bat-pollinated species, the loss of functional diversity was greater than expected by chance. Two main features could drive greater loss of biodiversity than expected by chance: loss of clumped species and loss of very unique species. Pollination and dispersal modes must be taken into account in conservation plans or ecological restoration strategies, since communities may be differentially vulnerable to the loss of one of these processes. Both functional and phylogenetic components of biodiversity should be considered, as consequences of extinctions for one are not necessarily the same as for the other

On dendrograms, ordinations and functional spaces: methodological choices or pitfalls?

A number of concerns persist regarding (i) how functional spaces should be quantified, (ii) how phylogenetic richness should be calculated, (iii) and how functional beta diversity should be calculated. Because all current methods have their shortcomings we think that analytical choices are as much a matter of knowing the limitations of the data and knowing the working hypothesis. Only then can one follow their personal choice, weighing up the shortcomings of different methods that, at the end of the day, usually produce qualitatively similar results

Leaf habit does not predict leaf functional traits in cerrado woody species

Plant species with a high leaf life span (LLS) commonly have a low specific leaf area (SLA), leaf nitrogen per unit mass (N), and phosphorous concentration (P), whereas species with low LLS have a high SLA, N and P. However, LLS tends to be longer in species growing in low-nutrient soils and, therefore, differences in LLS and other leaf traits may not be consistent with a plant classification according to leaf habit. Here we investigated whether leaf habit is consistent with leaf economic spectrum trade-offs in cerrado (a Neotropical savanna) woody species. We analyzed the SLA, N and P of 125 woody species with a distinct leaf habit (deciduous, semideciduous, brevideciduous or evergreen). We also gathered data on the LLS (33 species), maximum net photosynthesis per leaf area (Aarea, 56 species) and per leaf mass (Amass, 31 species), comprising the most extensive database analyzed so far for the cerrado. Differences among leaf habit groups were tested using generalized linear mixed models and ANOVA. We did not find differences in SLA and N among species with a distinct leaf habit, but deciduous species had a higher leaf P concentration than evergreens. Species did not differ in LLS and Amass, but Aarea varied among groups. Semideciduous species had higher Aarea values than deciduous and brevideciduous species, but all other groups had similar Aarea values. Because of the small difference in the LLS, SLA, leaf N, leaf P and maximum net photosynthesis, we argue that deciduous, brevideciduous, semideciduous and evergreen species may not constitute different functional groups in cerrado woody species.Pflanzenarten mit einer hohen Blattlebensdauer (LLS) haben gemeinhin eine geringe spezifische Blattfläche (SLA), sowie geringe Stickstoff- (N) und Phosphorkonzentrationen (P), während Arten mit geringer LLS hohe SLA-, N- und P-Werte aufweisen. Indessen tendiert die LLS dahin, bei Arten, die in nährstoffarmen Böden wachsen, länger zu sein, und deshalb könnten Unterschiede hinsichtlich der LLS und anderer Blatteigenschaften nicht mit einer Einteilung der Pflanzen nach Blattwurftypen übereinstimmen. Wir untersuchten an den Gehölzarten neotropischer Savannen (cerrado), ob der Blattwurftyp mit den Zielkonflikten im Ökonomiespektrum der Blätter in Einklang steht. Wir analysierten SLA, N und P von 125 Gehölzarten aus unterschiedlichen Blattwurftypen (laubwerfend, halblaubwerfend, kurzlaubwerfend oder immergrün). Wir berücksichtigten auch LLS-Daten (33 Arten), sowie die maximale Netto-Photosynthese je Blattfläche (Aarea, 56 Arten) und je Blattmasse (Amass, 31 Arten). Unterschiede zwischen den Blattwurftypen wurden mit GLMM und ANOVA getestet. Wir fanden keine Unterschiede hinsichtlich SLA und N zwischen den Blattwurftypen, aber die Blätter blattwerfender Arten hatten eine höhere P-Konzentration als die von immergrünen Arten. Es gab keine Unterschiede hinsichtlich LLS und Amass, aber Aarea variierte zwischen den Blattwurftypen. Halblaubwerfende Arten wiesen höhere Aarea-Werte als laubwerfende und kurzlaubwerfende Arten, aber alle anderen paarweisen Unterschiede waren nicht signifikant. Angesichts der geringen Unterschiede hinsichtlich LLS, SLA, N, P und Netto-Photosynthese postulieren wir, dass laubwerfende, halblaubwerfende, kurzlaubwerfende und immergrüne Arten keine funktionellen Gruppen von neotropischen Savannengehölzen begründen

Flower functional trait responses to restoration time

Abstract Questions: (1) Do species richness, flower functional diversity and redundancy of tree and non-tree species increase with restoration age; (2) are the flower traits of the reference forest similar to those found in restored sites; and (3) does species originality, in terms of unique combinations of different set of flower traits, differ among sites? Location: Forests restored by planting a high diversity assemblage of tree species, within the Atlantic Rain Forest, Brazil. Methods: We sampled all reproductive individuals (353 species) and classified them in terms of floral type, colour, size, generalization level and openness. As most trees were planted and non-tree species (sub-shrub, shrub, herbs, epiphytes, climbers and hemi-parasitic plants) were mostly naturally established, we analysed them in separate analyses. We compared species richness, functional diversity, redundancy and originality among sites. Moreover, we identified optimal subsets of flower traits to describe vegetation succession trends. Results: (1) Flower functional diversity of tree species could be achieved after two decades of restoration, but remained far from reference values for non-tree species. The same gap regarding reference values occurred with species richness, which increased over restoration periods, although were far from the reference values. Redundancy and functional diversity are not related to restoration age. (2) Red/burgundy colour, gullet and bell-funnel shape and large size were identified as indicators of the reference forest flowers. Different indicator traits were found for each restoration sites. (3) Sites were similar regarding originality for tree and for non-tree species. Conclusion: A highly diverse species pool seems to promise to increase richness and functional diversity of tree species, but not of non-tree species. Trait analyses have important implications for restoration projects and can be used instead of species taxonomic identity, especially for highly diverse tropical forests. Such functional diversity may be advanced through a priori definition of which species from the regional pool can be used in plantings for forest restoration, with special attention to functional traits of non-tree species. Otherwise, restoration sites in highly fragmented landscapes will not reach functional diversity of reference sites, even after a five-decade period

Taxonomic, functional, and phylogenetic beta diversity patterns of stream fish assemblages in tropical agroecosystems

This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionA multi‐faceted assessment of diversity is needed to improve our understanding of the mechanisms underlying biodiversity patterns and to reveal the impacts of land use alterations on β‐diversity. In this study, we analysed stream fish β‐diversity based on taxonomic, functional, and phylogenetic facets in an intensively cultivated tropical region. We sampled 43 stream reaches in the northwest of São Paulo State, south‐eastern Brazil. Each sampling site was characterised according to catchment‐scale features, landscape dynamic indicators, local‐scale features, and distance between stream reaches as network distance (a proxy for dispersal processes). As response variables, we considered taxonomic, functional, and phylogenetic β‐diversities coupled with a null‐model approach. For each β‐diversity metric, we calculated the mean overall value and tested whether the mean value was different from that expected by chance. To examine variation in β‐diversity for the three facets and determine the relative contributions of predictor variables, we used a distance‐based approach. Taxonomic and functional β‐diversities were higher from the expected value under a null model, suggesting that community assembly of these facets was dominated by deterministic processes. In contrast, phylogenetic β‐diversity was not different from that expected by chance, suggesting that the lineage composition of these assemblages was random. Furthermore, for all three facets, there was a positive environment‐β‐diversity relationship that was determined primarily by local‐scale features, whereas catchment features and landscape dynamic indicators were not important. In addition, none of the β‐diversity facets was correlated with stream network distance, indicating that dispersal processes were not strongly structuring fish assemblages. Our study suggested that although multiple facets of stream fish β‐diversity are ruled mainly by deterministic processes (e.g. species sorting), stochasticity is also important in community assembly. An interesting finding was the mismatch between phylogenetic versus taxonomic and functional β‐diversity. It is likely that the lack of non‐random structure in phylogenetic β‐diversity is due to the variation of phylogenetic signal in some functional traits. Given that landscape dynamic indicators were not correlated with measures of β‐diversity, we suggest that the recent sugarcane expansion in our study area probably has not critically affected stream fish β‐diversity. Also, it is possible that catchment variables presented little variability and did not overwhelm the effect of local environmental variables on β‐diversity. In conclusion, our study suggests that even highly disturbed tropical agroecosystems with a pool of species that is probably decimated, can still display a relatively high β‐diversity determined mainly by species sorting. These findings suggest key environmental features that must be considered in restoration or conservation of β‐diversity in agroecosystems. Specifically, since variation in β‐diversity was explained mainly by local‐scale environmental gradients, conservation schemes would ideally protect enough sites to capture this entire gradient. Overall, the knowledge of multiple facets can foment more effective conservation and restoration actions by providing a more comprehensive view of the structuring factors of assemblages