scholarly journals BIOGEOGRAPHICAL ANALYSIS OF SCARABAEINAE AND GEOTRUPINAE ALONG A TRANSECT IN CENTRAL MEXICO (COLEOPTERA, SCARABAEOIDEA)

2008 ◽  
Vol 40 (2) ◽  
pp. 273 ◽  
Author(s):  
Gonzalo Halffter ◽  
José R. Verdú ◽  
Juan Márquez ◽  
Claudia E. Moreno
Keyword(s):  
Species Composition ◽  
Transition Zone ◽  
Gulf Coast ◽  
Cloud Forest ◽  
Distribution Patterns ◽  
Mountain Range ◽  
Old World ◽  
High Plateau ◽  
Mexican Transition Zone ◽  
Tropical Lowlands

Scarabaeinae and Geotrupinae (Coleoptera, Scarabaeoidea) species composition is analyzed along a 150 km long altitudinal transect that runs S-NE in the Mexican Transition zone. The transect is located in the state of Hidalgo in central-eastern Mexico. The spatial unit of analysis is the landscape. The transect crosses five different landscapes. As terms of reference for studying the geographic distribution of the species, the entomofauna distribution patterns for the Mexican Transition zone were used. The transect includes all the patterns established by Halffter for this zone. Only genera with northern origins were found in landscape of the Pachuca Sierra (mountain range). The two landscapes of the High Plateau (temperate and arid) have one genus with a northern origin (<em>Onthophagus</em>), along with species belonging to genera with Neotropical origins that evolved on the High Plateau. For the landscapes of the zacualtipán Sierra and the slope down to the Gulf–Las Huastecas region genera of Neotropical affinity dominate, and there are also some species with a tropical distribution and of northern-Old World origin. The relationship between the mountains and the phyletic lineages or genera of northern origin and of recent entry into the Mexican Transition zone is confirmed, as is that between the tropical lowlands and the Neotropical lines or genera, also recent arrivals. Taxa that arrived a long time ago, of either origin, do not exhibit this geographic-ecological dependence. The Hidalgo Transect is compared with two other, similar transects sampled in the Mexican Transition zone: the Cofre de Perote–Gulf Coast transect (Veracruz) and that of Manantlán (Jalisco). In the mountain landscapes, High Plateau and Tropical Lowlands, there were no important differences in the species composition of the groups studied. In contrast, in the Transition landscape (zacualtipán in the Hidalgo Transect) there were very notable differences. In the Cofre de Perote transect, an important functional group is missing from the treeless habitats: the roller Scarabaeinae. For the same landscape, in Manantlán, lineages with Neotropical affinities are represented by a single species which completely dominates the beetles of northern affinities. This contrasts markedly with the Hidalgo and Cofre de Perote transects where, in the Transition landscape, Neotropical taxa are well represented. It appears that, unlike the tropical lowlands where (geologically recent) penetration of Neotropical taxa is massive in all three transects, in the transition landscapes (originally covered by cloud forest) the penetration of Neotropical taxa is highly variable, and depends on the mountain range in which they are found. In the Conclusions section, we analyze how the beetle fauna with different distribution patterns have contributed to the composition of the fauna of the Hidalgo Transect and in general that of the Mexican Transition zone, resulting in a mixture (genera with northern-Old World affinity, and genera with Neotropical affinities) that give the Mexican Transition zone its unique character.

scholarly journals Changes of bat species composition over altitudinal gradients on northern and southern aspects of the Soutpansberg mountain range, South Africa

Mammalia ◽  
2017 ◽  
Vol 81 (1) ◽  
Author(s):  
Sina M. Weier ◽  
Valerie M.G. Linden ◽  
Ian Gaigher ◽  
Patrick J.C. White ◽  
Peter J. Taylor
Keyword(s):  
South Africa ◽  
Species Composition ◽  
Species Distribution ◽  
Climate Model ◽  
Habitat Type ◽  
Distribution Patterns ◽  
Mountain Range ◽  
Altitudinal Distribution ◽  
Primary Determinant ◽  
Linear Decline

AbstractIn order to gain insight into the pattern of bat species composition over altitude and the environmental variables driving the observed pattern, we compared data from moist southern and drier northern aspects of the Soutpansberg range in northern South Africa. Acoustical monitoring and additional capturing of bats was used for analysis of species distribution patterns and comparisons of community composition. Bat activity generally followed a linear decline with increasing altitude, possibly related to reproductive females preferring lower altitudes. Species richness followed a hump-shaped distribution on the northern aspect and across the transect, whereas a pattern of a linear decline was observed on the southern aspect. Our study strongly supports a previously published climate model for insectivorous bats which assumes that water availability linked with temperature determines the shape of altitudinal distribution in bat species. Step-wise selection from multiple regression models retained habitat type and/or measures of habitat structure in all final models, supporting several other studies in that vegetation correlated to altitude is a primary determinant of bat species distribution over altitude. This study also supports that the Soutpansberg is a biodiversity hotspot for bats and emphasises that conservation efforts should by no means ignore the lower altitudes.

The germinable soil seedbank of Eucalyptus victrix grassy woodlands at Roy Hill station, Pilbara district, Western Australia

2004 ◽  
Vol 26 (1) ◽  
pp. 17 ◽  
Author(s):  
R. A. Graham ◽  
S. K. Florentine ◽  
J. E. D. Fox ◽  
T. M. Luong
Keyword(s):  
Species Composition ◽  
Western Australia ◽  
Perennial Grass ◽  
Summer Rainfall ◽  
Distribution Patterns ◽  
Grass Species ◽  
Surface Areas ◽  
Hill Station ◽  
Soil Seedbank ◽  
Germinable Seed

The paper reports soil seedbank species composition, of Eucalyptus victrix grassy woodlands, of the upper Fortescue River in the Pilbara District, Western Australia. In this study, our objectives were to investigate germinable soil seedbanks and species composition in response to three simulated seasons, using emergence. Variation in seed density from three depths was tested. Four field sites were sampled. Thirty samples were collected in late spring, after seed rain and before summer rainfall. From each sample spot, three soil depths (surface, 1–5, and 6–10 cm) were segregated from beneath surface areas of 100 cm2. Samples were later incubated in a glasshouse to simulate three different seasonal conditions (autumn, winter and spring). Germinating seedlings were recorded on emergence and grown until identified. Forty-one species germinated, comprising 11 grasses (7 annuals and 4 perennials), 25 annual herbs and 5 perennial herbs. Distribution patterns of germinable seed in both the important annual grass Eragrostis japonica and the perennial Eragrostis setifolia (a preferred cattle fodder species), suggest that seedbank accumulation differs among species and between sites. In part, this may be associated with the absence of grazing. Species with most total germinable seed were E. japonica (Poaceae; 603/m2), and the annual herbs Calotis multicaulis (Asteraceae; 346/m2), and Mimulus gracilis (Scrophulariaceae; 168/m2). Perennial grass seed was sparse. Spring simulation gave most germination (1059), followed by autumn (892) and winter (376) sets. Greatest species diversity was produced from the spring simulation (33 species), followed by autumn (26), and winter (22). Of the total germination, 92% came from 17 species that were represented in all three simulations. Of the 1227 grass seedlings counted, most were recruited from the surface soil (735), followed by the 5 (310) and 10 (182) cm depths. Marginally more grass seedlings germinated from the spring simulation (558) than the autumn set (523). Only 11.9% of grass germinants came from the winter simulation. All grass species recruited from the soil seedbanks had a C4 photosynthetic pathway. Except for Cenchrus ciliaris all grass species are native to Australia. Of the four sites sampled, one fenced to exclude cattle five years earlier had significantly more germination than the three unfenced sites. Seedbank sampling produced several new records for plants in the areas sampled.

Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen

2007 ◽  
Vol 19 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Niek J.M. Gremmen ◽  
Bart van de Vijver ◽  
Yves Frenot ◽  
Marc Lebouvier
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Altitudinal Gradient ◽  
Cross Validation ◽  
Strong Relationship ◽  
Distribution Patterns ◽  
Common Species ◽  
Important Variable ◽  
Diatom Species ◽  
Expected Species Richness

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.

scholarly journals DISTRIBUTION OF BRYOPHYTES OF AGALYK BASIN (KARATEPA MOUNTAINS OF ZERAVSHAN MOUNTAIN RANGE)

2015 ◽  
Vol 4 (2) ◽  
pp. 80-82
Author(s):  
Holmurod Akimovich Zhalov
Keyword(s):  
Species Composition ◽  
Point Of View ◽  
Mountain Range ◽  
Decayed Wood ◽  
Moss Species ◽  
Comparative Analyses ◽  
Wide Range ◽  
Identification Of Species ◽  
Characteristic Features ◽  
Research Period

From bryological point of view Zeravshan mountain range remains one of the least studied region. Identification of species composition of true mosses and their ecological-biological peculiarities were not earlier aimed for this region. In the territory of Agalyk basin Karatepa mountains can be divided into four types of substrates where moss species occur: soil, bark of living trees, decayed wood, stones. Characteristics of substrate groups become complicated due to wide range of ecological valency of moss species. Most species select not only one, but several substrates for their settling. During the research period in the soils of Agaliksay basin 20 species were recorded belonging to 13 genera and 10 family. On decayed wood 9 species were recorded belonging to 7 genera and 5 family. On the bark of living trees 15 moss species were recorded belonging to 8 genera and 6 family. Epilyte bryophytes occurred on rocky substrates. On rocky substrates of Agaliksay basin 34 moss species were recorded from 16 genera and 13 family. On the basis of results obtained during the study of substrate groups of mosses in Agaliksay basin, we have conducted comparative analyses of studied substrate groups with the purpose of determining their characteristic features.

scholarly journals Higher Variability in Fungi Compared to Bacteria in the Foraging Honey Bee Gut

2020 ◽  
Author(s):  
Leslie E. Decker ◽  
Priscilla A. San Juan ◽  
Magdalena L. Warren ◽  
Cory E. Duckworth ◽  
Cheng Gao ◽  
...  
Keyword(s):  
Species Composition ◽  
Microbial Communities ◽  
Honey Bee ◽  
Honey Bees ◽  
Plant Pathogens ◽  
Distribution Patterns ◽  
Model System ◽  
Pathogen Transmission ◽  
Host Health ◽  
Gut Symbionts

AbstractMicrobial communities in the honey bee gut have emerged as a model system to understand the effects of host-associated microbes on animals and plants. The specific distribution patterns of bacterial associates among honey bee gut regions remains a key finding within the field. The mid- and hindgut of foraging bees house a deterministic set of core species that affect host health. In contrast, the crop, or honey stomach, contains a more diverse set of bacteria that is highly variable in composition among individual bees. Whether this contrast between the two gut regions also applies to fungi, another major group of gut-associated microbes, remains unclear despite their potential influence on host health. In honey bees caught foraging at four sites across the San Francisco Peninsula, we found that fungi were much less distinct in species composition between the crop and the mid- and hindgut than bacteria. Unlike bacteria, fungi were highly variable in composition throughout the gut, and much of this variation was attributable to bee collection site. These patterns suggest that the fungi may be passengers rather than functionally significant gut symbionts. However, many of the fungi we found in the bees have been recognized as plant pathogens. Assuming that some fungi remain viable after passage through the gut, the distribution patterns we report here point to the potential importance of honey bees as vectors of fungal pathogens and suggest a more prominent role of honey bees in plant pathogen transmission than generally thought.Importance (Nontechnical explanation of why the work was undertaken)Along with bacteria, fungi make up a significant portion of animal- and plant-associated microbial communities. However, we have only begun to describe these fungi, much less examine their effects on most animals and plants. The honey bee, Apis mellifera, has emerged as a model system for studying host-associated microbes. Honey bees contain well-characterized bacteria specialized to inhabit different regions of the gut. Fungi also exist in the honey bee gut, but their composition and function remain largely undescribed. Here we show that, unlike bacteria, fungi vary substantially in species composition throughout the honey bee gut, contingent on where the bees are sampled. This observation suggests that fungi may be transient passengers and therefore unimportant as gut symbionts. However, our findings also indicate that honey bees could be major vectors of infectious plant diseases as many of the fungi we found in the honey bee gut are recognized as plant pathogens.

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