Geraldo Wilson Fernandes

A global method for calculating plant CSR ecological strategies applied across biomes world‐wide

Summary nCompetitor, stress-tolerator, ruderal (CSR) theory is a prominent plant functional strategy scheme previously applied to local floras. Globally, the wide geographic and phylogenetic coverage of available values of leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA) (representing, respectively, interspecific variation in plant size and conservative vs. acquisitive resource economics) promises the general application of CSR strategies across biomes, including the tropical forests hosting a large proportion of Earths diversity. nWe used trait variation for 3068 tracheophytes (representing 198 families, six continents and 14 biomes) to create a globally calibrated CSR strategy calculator tool and investigate strategy–environment relationships across biomes world-wide. nDue to disparity in trait availability globally, co-inertia analysis was used to check correspondence between a ‘wide geographic coverage, few traits’ data set and a ‘restricted coverage, many traits’ subset of 371 species for which 14 whole-plant, flowering, seed and leaf traits (including leaf nitrogen content) were available. CSR strategy/environment relationships within biomes were investigated using fourth-corner and RLQ analyses to determine strategy/climate specializations. nStrong, significant concordance (RVxa0=xa00·597; Pxa0<xa00·0001) was evident between the 14 trait multivariate space and when only LA, LDMC and SLA were used. nBiomes such as tropical moist broadleaf forests exhibited strategy convergence (i.e. clustered around a CS/CSR median; C:S:Rxa0=xa043:42:15%), with CS-selection associated with warm, stable situations (lesser temperature seasonality), with greater annual precipitation and potential evapotranspiration. Other biomes were characterized by strategy divergence: for example, deserts varied between xeromorphic perennials such as Larrea divaricata, classified as S-selected (C:S:Rxa0=xa01:99:0%) and broadly R-selected annual herbs (e.g. Claytonia perfoliata; R/CR-selected; C:S:Rxa0=xa021:0:79%). Strategy convergence was evident for several growth habits (e.g. trees) but not others (forbs). nThe CSR strategies of vascular plants can now be compared quantitatively within and between biomes at the global scale. Through known linkages between underlying leaf traits and growth rates, herbivory and decomposition rates, this method and the strategy–environment relationships it elucidates will help to predict which kinds of species may assemble in response to changes in biogeochemical cycles, climate and land use.

OCORRÊNCIA DE PLANTAS NÃO NATIVAS E EXÓTICAS EM ÁREAS RESTAURADAS DE CAMPOS RUPESTRES

A invasao por especies de plantas nao nativas representa um enorme problema para projetos de restauracao ambiental. Estas especies tem causado muitas vezes o fracasso do processo de restauracao, a perda de estoques nativos, prejuizos economicos e, certamente, sociais. O objetivo do presente trabalho foi listar e avaliar a ocorrencia de especies nao nativas em decorrencia do asfaltamento da MG-010 em areas restauradas nos campos rupestres da cordilheira do Espinhaco, Serra do Cipo, Brasil. Foram encontradas 23 especies de plantas nao nativas invadindo as areas restauradas. Entre essas especies, destacam-se as leguminosas Cajanus cajan, Chamaecrista flexuosa, Crotalaria pallida, Crotalaria spectabilis e Mimosa pigra e, entre as gramimeas, Andropogon bicornis, A. leucostachyus, Melinis repens, M. minutiflora, Paspalum paniculatum e Urochloa brizantha. A invasao das areas restauradas, bem como a das bordas da rodovia, por essas especies esta relacionada a melhoria dos solos ao longo das rodovias causada por tecnicas que utilizam uma mistura de calcario no preparo do leito estradal. A falta de um programa de monitoramento e gestao das areas restauradas, bem como das unidades de conservacao federal na qual estao inseridas, e outro fator que resulta em falhas no processo de restauracao, colocando em risco toda a biota regional.

Patterns of orchid bee species diversity and turnover among forested plateaus of central Amazonia

The knowledge of spatial pattern and geographic beta-diversity is of great importance for biodiversity conservation and interpreting ecological information. Tropical forests, especially the Amazon Rainforest, are well known for their high species richness and low similarity in species composition between sites, both at local and regional scales. We aimed to determine the effect and relative importance of area, isolation and climate on species richness and turnover in orchid bee assemblages among plateaus in central Brazilian Amazonia. Variance partitioning techniques were applied to assess the relative effects of spatial and environmental variables on bee species richness, phylogeny and composition. We hypothesized that greater abundance and richness of orchid bees would be found on larger plateaus, with a set of core species occurring on all of them. We also hypothesized that smaller plateaus would possess lower phylogenetic diversity. We found 55 bee species distributed along the nine sampling sites (plateaus) with 17 of them being singletons. There was a significant decrease in species richness with decreasing size of plateaus, and a significant decrease in the similarity in species composition with greater distance and climatic variation among sampling sites. Phylogenetic diversity varied among the sampling sites but was directly related to species richness. Although not significantly related to plateau area, smaller or larger PDFaith were observed in the smallest and the largest plateaus, respectively.