Drivers of ground-dwelling arthropod species richness and assemblage structure in the savannah biome

2016 ◽  
Author(s):  
Colin Schoeman
2004 ◽  
Vol 94 (2) ◽  
pp. 111-121 ◽  
Author(s):  
P.A.V. Borges ◽  
V.K. Brown

AbstractThe arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.


2020 ◽  
Vol 60 ◽  
pp. e20206032
Author(s):  
Walter Santos de Araújo ◽  
Kelly Christie dos Santos Costa ◽  
Luana Teixeira Silveira ◽  
Érica Vanessa Durães de Freitas ◽  
Yule Roberta Ferreira Nunes ◽  
...  

Several plant-related factors can influence the diversity of gall-inducing species communities. In the present study we performed an inventory of gall-inducing arthropods and we tested if the plant species richness and the abundance of super-host plants (Copaifera oblongifolia) influenced positively in the diversity of gall-inducing arthropod species. The study was realized in an area of Neotropical savanna (cerrado sensu stricto) in the Environmental Protection Area (EPA) of Rio Pandeiros, Minas Gerais, Brazil. Host-plant species and gall-inducing arthropods were sampled in 18 10 × 10 m plots distributed in the vegetation. In total we found 40 arthropod gall morphotypes, distributed on 17 botanical families and 29 plant species. Cecidomyiidae (Diptera) induced the most arthropod galls (85%), and the plant family Fabaceae had the greatest richness of gall morphotypes (16). The plant species Copaifera oblongifolia and Andira humilis (Fabaceae) were the most important host species with five and three morphotypes, respectively. Galling species richness was not affected by none of explanatory variables (plant species richness and abundance of super-host plants). On the other hand, galling species per plant species was negatively affected by plant species richness and positively affected by abundance of super-host plants. This is the first study of arthropod-induced galls conducted in EPA of Rio Pandeiros, Brazil. Our results corroborate previous studies that highlight the importance of super-host plants for galling arthropod diversity on a local scale.


Author(s):  
Araceli Jaquelín Mercado-Santiago ◽  
Pablo Hernández-Alcántara ◽  
Vivianne Solís-Weiss

The deepsea fauna from the southern Gulf of California is currently poorly known, with only 193 species reported to date. The aim of this study was to analyze the composition, density, species richness, and taxonomic diversity (Δ) of the deepsea polychaetes of this region. Fifteen stations (238–2900 m depth) were sampled in 2012 and 2013. Eighty-four species from 58 genera and 26 families were identified. Density ranged from 4.76 to 42.86 ind 0.1m−2 and was not significantly correlated with depth; species richness ranged from 2 to 17 species per station, the lowest (2–6 species) occurring between depths of 651 and 915 m. Four assemblages were identified associated with depth (RANOSIM = 0.43, P = 0.002) and geographic position (RANOSIM = 0.56, P = 0.001): Prionospio elhersi–Subadyte mexicana–Syllis alternata (<350 m depth) and Aricidea sp. A–Ninoe jessicae (600–1000 m) in the western gulf; Onuphis similis–Aricidea (Acmira) simplex (1300–1600 m) and Aglaophamus paucilamellata–Sthenolepis spargens (>1200 m) in the middle gulf; stations 14A and 2A, sharing only their position at the far eastern gulf, remained isolated from any other assemblage. The highest diversity was found at 1300–1600 m (Δ = 86.1) and at >2000 m (Δ = 83–98) but decreased to Δ = 61.85 at 600–1000 m. The assemblage structure based on genera and family levels were similar to those based on species (Rho > 0.6), suggesting that either of the former two could be suitable surrogates for monitoring changes at the studied depths.


2010 ◽  
Vol 25 (6) ◽  
pp. 941-954 ◽  
Author(s):  
T. Sattler ◽  
P. Duelli ◽  
M. K. Obrist ◽  
R. Arlettaz ◽  
M. Moretti

2005 ◽  
Vol 2005 ◽  
pp. 236-236
Author(s):  
A. J. Helden ◽  
A. Anderson ◽  
G. Purvis

Grassland management practices, such as grazing, strongly affects the biodiversity of grassland arthropods; increasing grazing intensity causes a general decline in species richness (Morris, 2000). One of the aims of the Rural Environment Protection Scheme (REPS) is to conserve and enhance biodiversity within Irish agricultural land (Feehan et al., 2002). In order to determine the effectiveness of this aspect of REPS, one must compare the relative biodiversity of grassland under REPS with that of conventionally managed grassland. Aiming to determine whether species richness was higher in REPS-compatible compared with a standard system of management, we measured the species richness of grassland arthropods within two contrasting grassland treatments within an experimental study of suckler beef production.


Author(s):  
Joaquim N.S. Santos ◽  
Rafaela de S. Gomes ◽  
Ruan Managna Vasconcellos ◽  
Débora de Souza Silva ◽  
Francisco Gerson Araújo

We examined the benthic macroinfauna at three strata during two seasons (winter and summer) on two sandy beaches (dissipative and reflective) in south-eastern Brazil. The hypothesis raised is that effects of morphodynamics and zonation determine the structure of macroinfauna, with dissipative beaches having comparatively higher species richness and density than the reflective beaches. Flamengo beach (dissipative) had higher species richness but lower density compared to Grumari beach (reflective). A high dissimilarity in assemblage structure (91.75%) was detected between the two beaches. Zonation in the occurrence of macroinfauna was detected for the two beaches in the two examined seasons. At Grumari beach, Emerita brasiliensis occurred mainly in stratum 1 (intertidal swept zone) while Saccocirus sp. occurred in stratum 2 (infralittoral at 0.5 m depth), whereas at Flamengo beach E. brasiliensis and Enoploides sp. had the highest density in stratum 1 (intertidal swept zone) whereas Scolelepis goodbodyi and Donax uncinata dominated in stratum 3 (infralittoral at 1.0 m depth). Scolelepis goodbodyi, Dispio uncinata, Enoploides sp., Nematoda and Trileptium sp. were associated with higher a Dean parameter and content of organic matter at Flamengo beach. In contrast, Hastula sp., Donax sp., Pisionidens indica, Hemipodus californiensis, Saccocirus sp. and Phyllodocidae were associated with the higher wave period and grain size of Grumari beach. The hypothesis that macroinfauna structure differs between the beaches and strata was confirmed, with the dissipative beaches having comparatively higher richness but lower density than the reflective beaches.


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