Fixed or mixed? Variation in tree functional types and vegetation structure in a forest-savanna ecotone in West Africa

We analysed thirty-five 400-m2 plots encompassing forest, savanna and intermediate vegetation types in an ecotonal area in Ghana, West Africa. Across all plots, fire frequency was over a period of 15 years relatively uniform (once in 2–4 years). Although woodlands were dominated by species typically associated with savanna-type formations, and with forest formations dominated by species usually associated with closed canopies, these associations were non-obligatory and with a discrete non-specialized species grouping also identified. Across all plots, crown area index, stem basal area and above-ground biomass were positively associated with higher soil exchangeable potassium and silt contents: this supporting recent suggestions of interplays between potassium and soil water storage potential as a significant influence on tropical vegetation structure. We also found an average NDVI cover increase of ~0.15% year−1 (1984–2011) with plots dominated by non-specialized species increasing more than those dominated by either forest- or savanna-affiliated species. Our results challenge the traditional view of a simple forest vs. savanna dichotomy controlled by fire, and with our newly identified third non-specialized species grouping also potentially important in understanding ecotonal responses to climate change.

Carabid beetles in peatlands - what are bog species? Clear definitions of tyrphobiontic and tyrphophilic species as used in the "Bavarian bog species basket"

Peatland species are endangered because of peat extraction and drenching of peatland in many regions, and thus are of great conservation concern. Often times, the trait of being "tyrphobiontic" or "tyrphopilous" is defined differently in the literature, yielding ambigous results. Frequently, studies of peatland fauna do not clearly define which species are characteristic of peatlands, instead focussing on other traits like red data book status etc. The group of peatland specialists should be definied by their affinity to the habitat trait of peaty soil. For many species, further factors are also relevant, like habitat tradition, elevation and regional climate, vegetation types etc., but peaty soil is a common denominator. The "Bavarian bog species basket" lists all species from different species groups that are bog species, grouping them into three clearly defined categories of peatland affinity. For carabids, a list of all 26 species in that basked is presented, and examples provided how these differ in their affinity to different bog habitats, and to bog habitats overall.

ECOLOGICAL AND FUNCTIONAL CLUSTERING OF FORESTAL SPECIES IN THE SOUTH WESTERN AMAZONIA

ABSTRACT The aim of this study was to perform ecological and functional clustering of tree species in southwestern Amazon. Developed from data from 95 permanent plots of 1 ha each, all individuals with diameter at breast height (DBH) ≥10 cm were measured. The species grouping was performed in three stages: (1) cluster analysis, using the variables: diameter annual periodic increment -(IPADAP) considering three competition levels (high, medium and low) and the 95th percentile of the diameters (P95) cumulative frequency distribution (Ward hierarchical method); (2) Discriminant analysis, using the variables P95 and IPADAP by Fisher's method and (3) subjective stage, considering the species ecological characteristics. The Ward and Fisher methods used for discriminant and cluster analyses were effective for species grouping resulting on the formation of 10 groups. Variables: IPADAP and and P95 were efficient on the formed groups discrimination.. Variations in the growth rates for the overall mean data were reduced wen calculated for each group of species.

Reassessing taxonomic relationships in the Berkheya clade (Asteraceae, Arctotideae–Gorteriinae): the utility of achene morphology

The genus Berkheya is paraphyletic with the related genera Cullumia, Cuspidia, Didelta and Heterorhachis embedded within a broader clade termed the ‘Berkheya clade’. As a contribution towards reassessment of species relationships and delimitation of species groupings within the clade, the utility of external achene morphology for supporting natural species groups within the clade was evaluated. Achenes from 67 species and 10 infraspecific taxa were examined, including representatives of each genus currently recognised in the Berkheya clade. Achene pubescence and pappus characteristics (e.g., scale shape and number of scales within a series) were indicated to be particularly variable and thus less reliable for assessment of species relationships. Of the currently recognised genera, only segregation of Cullumia was supported by achene and pappus characteristics. Species groupings implicit in Roessler’s infrageneric classification of eight series within Berkheya were to a large extent supported. However, in particular, series Speciosae was indicated to be a disparate species grouping and the distinction of series Angustae and Cruciatae is not supported by achene and pappus morphology. Achene and pappus characteristics suggest several novel species groupings (e.g. an affinity between Berkheya cuneata, B. ferox and B. spinosa). Although the taxonomic sampling in published molecular phylogenetic analyses is limited, achene and pappus morphology partially supports clades resolved in prevailing phylogenetic reconstructions for the clade. More complete sampling in future molecular phylogenetic analyses is required to test novel species affinities suggested in the present study and to explore the evolution of the achene and pappus in the Berkheya clade.

Diet and ecomorphological relationships of four cichlid species from the Cuiabá River basin

ABSTRACT Relationship between diet and morphology of cichlid were analyzed considering that the trophic apparatus determines differential food use among species. Cichlasoma dimerus and Satanoperca pappaterra showed a generalist diet, while Chaetobranchopsis australis and Crenicichla vittata consumed zooplankton and fish, respectively. Significant correlation between morphology and diet was not found, but C. australis differed from the others species in the upper mouth and longer gill rakers. The morphology data and food size segregated the cichlids into three groups. The first was comprised by C. australis, which has many and longer gill rakers and a more protractile mouth, the second by C. vittata, which have a larger and more-protruded mouth and the third by S. pappaterra and C. dimerus, with a smaller and lower mouth. The latter two groups have more widely spaced gill rakers and consumed larger food. Overall, our results showed different patterns of species grouping when considering morphological or diet data. However, to C. australis the gill rakers determine both the type and size of food.