The distribution of ants on the Wessel and English Company Islands, in the seasonal tropics of Australia’s Northern Territory

1998 ◽  
Vol 46 (6) ◽  
pp. 557 ◽  
Author(s):  
J. C. Z. Woinarski ◽  
Hanna Reichel ◽  
A. N. Andersen

A total of 74 ant species (from 23 genera) was recorded from 195 quadrats (50 × 50 m) from 39 continental islands off Arnhem Land, Northern Territory. In general, the ant fauna comprised generalist species widespread on the north Australian mainland. The functional group composition was also comparable to that of similar environments on the north Australian mainland. The ant fauna was not tightly structured. There were few habitat specialists, no species showed a clear preference for smaller islands, and only a few species showed unequivocal preferences for larger islands. There were no clear cases of congeneric, or otherwise ecologically similar, species replacing each other on different islands. In contrast to the north Australian mainland, there were no significant differences between habitats in ant species richness. However, the functional group composition varied significantly between the eight main habitats sampled across the islands, in a manner consistent with that reported for the mainland. The number of ant species recorded per island was most closely related to island size (80% of the deviance explained), but there was only slight or no relationship between island size and the number of species at the quadrat scale. Functional group composition varied between islands, with small islands supporting a relatively high proportion of Generalised Myrmicinae species. Low-lying (and presumably intermittently inundated) islands supported a higher proportion of Dominant Dolichoderinae and few Specialist Predators and Tropical Climate Specialist species. Very small islands supported a relatively high proportion of Dominant Dolichoderinae species. These differences are largely attributable to inter-island differences in habitat availability and disturbance regimes, and to differences between functional groups in dispersability, competitive ability and ecological flexibility. Species richness was little influenced by the extent of island isolation. Patterning in the ant fauna of these islands parallels that reported for islands elsewhere.

1999 ◽  
Vol 47 (1) ◽  
pp. 87 ◽  
Author(s):  
J. C. Z. Woinarski ◽  
C. Palmer ◽  
A. Fisher ◽  
K. Brennan ◽  
R. Southgate ◽  
...  

Eighteen non-marine mammal species (including seven species of bats) were recorded from a total of 49 islands in the Wessel and English Company island chains off north-eastern Arnhem Land, Northern Territory. Most individual species were restricted to, or had higher incidence on, larger islands, and species richness as a whole increased as island size increased. The most notable exception was the semi-aquatic Hydromys chrysogaster, which occurred relatively equitably across island sizes; this species, two bat species and the macropod Petrogale brachyotis were recorded from islands smaller than 10 ha. However, the variation between islands in the number of native terrestrial mammal species was not best predicted by island size, but rather by a combination of sampling effort and altitude (which explained 64% of the deviance in species richness), or altitude and distance to larger land mass (explaining 63% of deviance). Richness–area patterns for individual islands in these chains were reasonably consistent with those of other islands sampled in northern Australia. However, the fauna of the Wessel and English Company groups as a whole was less rich than that of the Pellew and Kimberley islands, and individual islands appeared to have lower species richness than comparable mainland areas. Species that were notably absent or that were recorded from relatively few islands include large macropods, Tachyglossus aculeatus, Antechinus bellus, Phascogale tapoatafa, Sminthopsis spp., Mesembriomys gouldii, Rattus colletti, Leggadina lakedownensis and Pseudomys calabyi. Some of these species may be absent through lack of suitable habitat; others have presumably disappeared since isolation, possibly due to Aboriginal hunting. Richness at the quadrat (50 × 50 m) scale was generally very low. Habitat relationships are described for the 7 species recorded from more than 5 quadrats. At a quadrat-scale, the richness of native mammals was greater on islands larger than 1000 ha than on islands smaller than 1000 ha. Quadrat-scale species richness varied significantly among the islands sampled by the most quadrats (even when the comparison was restricted to either of the two most extensive vegetation types), but this variation was not closely related to either area or altitude. The two most frequently recorded species, the rodents Melomys burtoni and Zyzomys argurus, showed distinct habitat segregation on islands where both were present, but tended to expand their habitat range on islands where only one of the species occurred. The most notable conservation feature of the mammal fauna of the Wessel and English Company Islands is the occurrence of the golden bandicoot, Isoodon auratus, a vulnerable species apparently now extinct on the Northern Territory mainland. Four feral animal species (Rattus rattus, Canis familiaris, Bubalus bubalis and Capra hircus) were recorded from a total of 6 islands.


2016 ◽  
Vol 38 (5) ◽  
pp. 511 ◽  
Author(s):  
Zhao Na ◽  
Wang Zhengwen ◽  
Shao Xinqing ◽  
Wang Kun

The diversity–stability relationship has been addressed and debated for decades, but how this relationship is affected by nutrient availability remains contentious. In the present study we assessed the effects of plant diversity, in terms of species richness, functional group composition and functional trait diversity, on the spatial stability of net primary productivity (NPP) following nitrogen and phosphorus application. In addition, we explored how functional traits at the species level contribute to the spatial stability of NPP. The results support the hypothesis that greater diversity leads to higher spatial stability. This relationship was highly dependent on soil nutrient availability, and increasing species richness or functional trait diversity significantly increased spatial variation of NPP under a high N fertilisation level. The effects of high mineral fertilisation rates may perhaps have masked the effects of plant diversity. Although species richness or functional trait diversity of the original and modified communities from which species with particular functional traits had been removed were significantly different, there were no differences in the coefficients of variation in the NPP of those communities. The lack of difference demonstrated that the relationship between spatial variability and biodiversity depended on the measure of diversity applied and that the functional group composition exerted a stronger effect than other diversity measures. Further analyses revealed that spatial stability of NPP was enhanced with increased diversity in vegetative plant height, rooting depth and the presence of legume, and diminished with diversity in the root system type and life cycle under some fertilisation treatments. The present study demonstrates that the relationship between biodiversity and ecosystem functioning is variable with different diversity, identity and environmental factors. Evaluating the contribution of particular traits to community stability will ultimately help us better understand the mechanisms underlying the diversity–stability relationship.


1997 ◽  
Vol 45 (5) ◽  
pp. 523 ◽  
Author(s):  
C. Vanderwoude ◽  
A. N. Andersen ◽  
A. P. N. House

The biogeography and structure of ant communities were examined over a 12-month period at a dry open eucalypt forest in south-eastern Queensland. Three sites were monitored, each with a distinct long-term burning history: burned annually since 1952, burned periodically since 1973, and unburned since 1946. A total of 89 species from 42 genera was recorded over all trapping periods, with the richest genera being Iridomyrmex, Camponotus and Pheidole, each with eight species. Site species richness was 74, 63 and 43, respectively, at the annually burned, periodically burned and the unburned site. We compared the ant community in this forest with those at other forested sites in eastern Australia. Overall, the south-eastern Queensland community was located on the overlap between the Bassian and Torresian zones (not dominated by either element), while the functional-group composition resembled those of both tropical savannas and cool-temperate woodlands. There were readily discernible differences between sites in terms of biogeographical and functional-group composition; and between the unburned site and both burned sites in terms of abundance and species richness. The relative abundance of Iridomyrmex spp. increased with burning frequency while the relative abundance of Bassian species decreased with burning frequency. Species richness and abundance at the burned sites were similar, but substantially higher than at the unburned site. The community characteristics of the three sites were readily distinguishable, indicating that ant communities may play a valuable role in detecting ecological changes in forested landscapes in south- eastern Queensland.


2017 ◽  
Vol 149 (4) ◽  
pp. 491-503 ◽  
Author(s):  
Aaron J. Bell ◽  
Iain D. Phillips ◽  
Scott E. Nielsen ◽  
John R. Spence

AbstractWe tested the applicability of the “passive sampling” hypothesis and theory of island biogeography (TIB) for explaining the diversity of forest-dwelling carabid assemblages (Carabidae: Coleoptera) on 30 forested islands (0.2–980.7 ha) in Lac la Ronge and the adjacent mainland in Saskatchewan, Canada. Species richness per unit area increased with distance to mainland with diversity being highest on the most isolated islands. We detected neither a positive species-area relationship, nor significant differences in species richness among island size classes, or between islands and the mainland. Nonetheless, carabid assemblages distinctly differed on islands <1 ha in area and gradually approached the structure of mainland assemblages as island area increased. Small islands were characterised by abundant populations of small-bodied, winged species and few if any large-bodied, flightless species like Carabus taedatus Fabricius. Our findings suggest that neither the “passive sampling” hypothesis nor the theory of island biogeography adequately explain carabid beetle diversity patterns observed among islands in Lac la Ronge. Instead, we hypothesise that population processes such as higher extinction rates of large-bodied, flightless species and the associated release of smaller-bodied, flying species from intra-guild predation on small islands contribute to observed differences in the structure of carabid assemblages between islands.


2007 ◽  
Vol 55 (6) ◽  
pp. 363 ◽  
Author(s):  
Alan N. Andersen ◽  
Laura T. van Ingen ◽  
Ricardo I. Campos

Rainforest in the tropical savanna landscapes of monsoonal Australia is of high biogeographic interest because it occurs as numerous small and isolated patches, and supports a fauna that contrasts markedly with that of the surrounding savanna. The overall ant fauna of monsoonal rainforest is known reasonably well, but with just one exception (Holmes Jungle in Darwin) the faunas of individual rainforest patches have been only superficially studied. This paper comprehensively documents an ant fauna of a spring-fed rainforest patch at the Territory Wildlife Park (TWP) near Darwin, contrasts it with that of surrounding savanna, and compares it with the Holmes Jungle fauna. Ants were sampled at 21 locations within the TWP rainforest, using Winkler sacs for litter-dwelling species (160 samples), standard pitfall traps for ground-active species (75 traps), and baited pitfall traps taped to trees for arboreal species (75 traps). In total, 43 species were collected, with 35 recorded in leaf litter, 24 in ground pitfall traps and 12 in arboreal pitfall traps. Species of Paratrechina and Pheidole collectively comprised 75% of all individuals recorded. Species richness was far higher in the surrounding savanna, and the rainforest and savanna faunas had markedly different species and functional group composition. The rainforest fauna at TWP was remarkably similar to that at Holmes Jungle. The rainforest/savanna contrast in ant diversity across northern Australia is the reverse of that occurring in Neotropical savanna landscapes.


2008 ◽  
Vol 19 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Jaan Liira ◽  
Torsten Schmidt ◽  
Tsipe Aavik ◽  
Paul Arens ◽  
Isabel Augenstein ◽  
...  

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 170
Author(s):  
Gladys N. Benitez ◽  
Glenn D. Aguilar ◽  
Dan Blanchon

The spatial distribution of corticolous lichens on the iconic New Zealand pōhutukawa (Metrosideros excelsa) tree was investigated from a survey of urban parks and forests across the city of Auckland in the North Island of New Zealand. Lichens were identified from ten randomly selected trees at 20 sampling sites, with 10 sites classified as coastal and another 10 as inland sites. Lichen data were correlated with distance from sea, distance from major roads, distance from native forests, mean tree DBH (diameter at breast height) and the seven-year average of measured NO2 over the area. A total of 33 lichen species were found with coastal sites harboring significantly higher average lichen species per tree as well as higher site species richness. We found mild hotspots in two sites for average lichen species per tree and another two separate sites for species richness, with all hotspots at the coast. A positive correlation between lichen species richness and DBH was found. Sites in coastal locations were more similar to each other in terms of lichen community composition than they were to adjacent inland sites and some species were only found at coastal sites. The average number of lichen species per tree was negatively correlated with distance from the coast, suggesting that the characteristic lichen flora found on pōhutukawa may be reliant on coastal microclimates. There were no correlations with distance from major roads, and a slight positive correlation between NO2 levels and average lichen species per tree.


Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 239
Author(s):  
Wei Wang ◽  
Long Liang ◽  
Yaoli Peng ◽  
Maria Holuszko

Micro-Fourier transform infrared (micro-FTIR) spectroscopy was used to correlate the surface chemistry of low rank coal with hydrophobicity. Six square areas without mineral impurities on low rank coal surfaces were selected as testing areas. A specially-designed methodology was applied to conduct micro-FTIR measurements and contact angle tests on the same testing area. A series of semi-quantitative functional group ratios derived from micro-FTIR spectra were correlated with contact angles, and the determination coefficients of linear regression were calculated and compared in order to identify the structure of the functional group ratios. Finally, two semi-quantitative ratios composed of aliphatic carbon hydrogen, aromatic carbon hydrogen and two different types of carbonyl groups were proposed as indicators of low rank coal hydrophobicity. This work provided a rapid way to predict low rank coal hydrophobicity through its functional group composition and helped us understand the hydrophobicity heterogeneity of low rank coal from the perspective of its surface chemistry.


Author(s):  
Katherine C Kral-O’Brien ◽  
Adrienne K Antonsen ◽  
Torre J Hovick ◽  
Ryan F Limb ◽  
Jason P Harmon

Abstract Many methods are used to survey butterfly populations, with line transect and area surveys being prominent. Observers are typically limited to search within 5 or 10 m from the line, while observers are unrestricted in larger specified search regions in area surveys. Although methods differ slightly, the selection is often based on producing defendable data for conservation, maximizing data quality, and minimizing effort. To guide method selection, we compared butterfly surveys using 1) line versus area methods and 2) varying width transects (5 m, 10 m, or unrestricted) using count data from surveys in North Dakota from 2015 to 2018. Between line and area surveys, we detected more individuals with area surveys, even when accounting for effort. However, both methods accumulated new species at similar rates. When comparing transect methodology, we detected nearly 60% more individuals and nine more species when transect width increased from 5 m to unrestricted, despite similar effort across methodology. Overall, we found line surveys slightly less efficient at detecting individuals, but they collected similar species richness to area surveys when accounting for effort. Additionally, line surveys allow the use of unrestricted-width transects with distance sampling procedures, which were more effective at detecting species and individuals while providing a means to correct count data over the same transect length. Methods that reduce effort and accurately depict communities are especially important for conservation when long-term datasets are unavailable.


1887 ◽  
Vol 42 (251-257) ◽  
pp. 316-318

Carriacou is a small island situated about twenty miles to the north of the island of Grenada, the chief of the Windward group, and furnished an excellent site for the observation of the last solar eclipse. Most of the observers sent by the Eclipse Committee of the Royal Society to the West Indies in August of last year remained at Grenada, or on the small islands in its immediate vicinity, whilst Mr. Maunder and myself occupied the more distant northern station, where the totality was slightly diminished in duration. The work proposed for Mr. Maunder was to secure a series of photographs of the corona, with exposures of 40s. and under, and also to obtain two photographs of the spectrum of the corona with the longest exposures possible.


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