Elevational zonation of birds,insectivores, rodents and primates on the slopes of the Andringitra Massif,Madagascar

A review is presented of the birds, lipotyphlans, rodents and lemurs occurring across an elevational transect from 720 to 2450 m within the 31160ha Parc National (PN) d'Andringitra in south-central Madagascar. The broad range of habitats within this reserve consists of lowland forest, montane forest, sclerophyllous forest, montane thicket, to open areas of bare rocks covered by geophytes. Eight different zones were surveyed across this elevational range for most of these four vertebrate orders. On the basis of these surveys and other sources of information, 106 species of birds, 16 species of Lipotyphla, 11 species of rodents (including two introduced species) and 13 species of primates are documented within the reserve. Surveys of the carnivores are incomplete, although eight species, three of which are introduced, have been recorded in the reserve. Forty-eight species of non-volant mammals are known from the Andringitra Massif, 43 of which are endemic to Madagascar. The highest species richness for birds was 85 species in the disturbed lowland forest at 720m zone and there was a subsequent reduction in the number of species at each site with increasing elevation. The two zones at 1210 and 1625 m with montane and mixed montane/sclerophyllous forest had the greatest species richness of non-volant mammals with 26 species (25 non-introduced). Lemurs showed decreasing species richness with increasing elevation. Small mammals showed broad elevational ranges and high species diversity in the middle to upper portion of the forest zone, with lipotyphlans peaking at 1990 m and rodents between 1625 and 1960 m. About 88 species of extant native rodents, carnivores, lipotyphlans and primates are currently recognized to occur on Madagascar. Thus, the PN d'Andringitra holds nearly 50% of the total known fauna of these groups from the island. This relatively small reserve plays a major role in safe-guarding a large proportion of the non-volant mammal fauna of Madagascar.     

Herpetological diversity across intact and modified habitats of Nosy Komba Island,Madagascar

A six month herpetological survey was undertaken between March and September 2015 on Nosy Komba, an island off of the north-west coast of mainland Madagascar which has undergone considerable anthropogenic modification. A total of 14 species were found that have not been previously recorded on Nosy Komba, bringing the total island diversity to 52 (41 reptiles and 11 frogs). The species assemblage, richness and abundance of four distinct habitat types were compared: closed-canopy forest, disturbed-canopy forest, shade-grown coffee plantation and mixed open plantation. The anthropogenic habitats on Nosy Komba were found to be of high conservation value for reptile species, where species richness and abundance found during surveys was equal to or higher than closed-canopy forest. By contrast, the abundance and species richness for frogs was reduced in anthropogenic habitats, especially in sun-exposed plantations. The forested areas of Nosy Komba contain twelve IUCN threatened species (9 reptiles and 3 frogs). Of these, Uroplatus henkeli, Uroplatus ebenaui, Phelsuma seippi, Zonosaurus subuniclor, Stumpffia psologlossa and Stumpffia pygmaea were also found in shade-grown coffee plantations, demonstrating the conservation value of these anthropogenic environments. Five threatened species on Nosy Komba were found exclusively in forested areas: Brookesia minima, Brookesia ebenaui, Lygodactylus madagascariensis, Rhombophryne testudo and Thamnosophis stumpffi. Our surveys demonstrate the importance of Nosy Komba for conserving regionally endemic and threatened species, and the often under-appreciated value of anthropogenic environments in species conservation, when also coupled with the protection of primary forest.     

Diversity and species composition of Araneidae,Tetragnathidae and Nephilidae in different levels of disturbed habitats in Trinidad,West Indies

ABSTRACT

An increasing amount of natural vegetation is being cleared in the tropics, prompting the questions of how disturbance influences the fauna, and the possible value of disturbed habitats as a means to conserve biodiversity. Three habitat types experiencing difference levels of disturbance farmland (most disturbed), cocoa plantations, and secondary forest (least disturbed) were examined in this study. Six localities of each of three disturbed habitat types were sampled for the spider families Araneidae, Tetragnathidae and Nephilidae, and compared to previous data from 46 localities of 16 natural habitats. Observed and estimated species richness, evenness and dominance of orb-weaving spiders differed significantly among the disturbed habitat types, with secondary forest having greater diversity than the mean for natural habitats in all these measures. Overall, disturbed habitats were not significantly different from natural habitats in species richness, evenness and dominance, and were therefore of conservation value.     

Poisonous plants of Utah

Bird species density, diversity, and species richness in relation to habitat and seasonal variations were studied in the Betatakin Canyon area of Navajo National Monument, Arizona. The two most prominent habitat types are a riparian forest deep in the canyon bottom and a mature pinyon-juniper woodland on the mesas and slopes above the canyon. One hundred thirty-five species of birds were encountered during the study and recorded by season and habitat. The avifauna assemblages demonstrate definite habitat selection into groups associated with the riparian and pinyon-juniper woodland communities. Diversity, density, and species richness were greatest in the riparian habitat during the spring and summer months. The differences in bird community composition were greater between seasons than between habitats. Pinyon pine and Gambel oak were highly selected as perch sites in the pinyon-juniper and riparian areas, respectively.     

Vegetation, soils, and hydrogeomorphology of riparian patch types of a dryland river

From a landscape perspective, riparian corridors can be viewed as mosaics of vegetation patches. We delineated 10 patch types within the floodplain of the San Pedro River (Arizona) on the basis of physiognomy, dominant overstory species, and tree size class; and we assessed differences in hydrogeomorphology, vegetation structure, plant species richness, and soil chemistry and texture. Patches of tamarisk ( Tamarix ), an introduced species, fell within the continuum of variation shown by other patch types in the landscape mosaic. Among the tree-dominated types, cottonwood-willow ( Populus-Salix ) and tamarisk patches were inundated more frequently than mesquite ( Prosopis ) patches, while cottonwood-willow patches had shallower groundwater than tamarisk or mesquite patches. Due to the wetter conditions, cottonwood-willow patches had a high relative abundance of wetland and exotic species in the understory. Tamarisk patches and wet shrublands ( Baccharis salicifolia—Salix exigua ) had high woody stem densities while cottonwood-willow patches had dense canopy cover. In association with differences in canopy cover, cottonwood-willow patches had low herbaceous species richness but high woody species richness, while tamarisk patches had high herbaceous and low woody species richness. Soil electrical conductivity, silt content, organic matter content, and available phosphorus increased from young to old stands of both tamarisk and cottonwood-willow, often resulting in greater differences between patches of different size/age class than between patches with different dominant species. Surface soil salinity (electrical conductivity) was low in all patches, including those dominated by tamarisk. Nitrate was abundant in soils of tamarisk patches (perhaps reflecting their high clay content) and wet shrubland patches. Dry shrublands ( Hymenoclea-Ericameria ) and wet shrublands were similar to young forest patches in having coarse soils with little organic matter.     

Bird community composition in relation to habitat and season in Betatakin Canyon, Navajo National Monument, Arizona

Bird species density, diversity, and species richness in relation to habitat and seasonal variations were studied in the Betatakin Canyon area of Navajo National Monument, Arizona. The two most prominent habitat types are a riparian forest deep in the canyon bottom and a mature pinyon-juniper woodland on the mesas and slopes above the canyon. One hundred thirty-five species of birds were encountered during the study and recorded by season and habitat. The avifauna assemblages demonstrate definite habitat selection into groups associated with the riparian and pinyon-juniper woodland communities. Diversity, density, and species richness were greatest in the riparian habitat during the spring and summer months. The differences in bird community composition were greater between seasons than between habitats. Pinyon pine and Gambel oak were highly selected as perch sites in the pinyon-juniper and riparian areas, respectively.     

Effects of habitat type and degradation on avian species richness in Great Basin riparian habitats

The overwhelming majority of bird species in the Great Basin region are found in riparian habitats. However, most previous research on the impact of change in habitat condition through degradation on these bird communities failed to account for the large intersite differences, in both habitat type and extent of degradation. We examined songbird communities in 4 riparian habitat types (meadows, willow-birch-, and aspen-dominated forest stands) during summers 1994 (last year of a 7-yr drought) and 1995 (following the 6th wettest winter recorded) in the Toiyabe Mountain Range of central Nevada. Habitat degradation significantly influenced bird species richness in riparian areas, but the impact was dependent upon habitat type. While meadow bird communities were affected adversely by habitat degradation, with significant drops in species richness on degraded sites, bird species richness in forested riparian habitats was consistently greater on degraded sites. Data for the 6 most common species seen during our study indicated that degradation may have influenced distribution of American Robins ( Turdus migratorius ) and Yellow Warblers ( Dendroica petechia ), but habitat type was the best predictor of abundance for House Wrens ( Troglodytes aedon ), Red-naped Sapsuckers ( Sphyrapicus nuchalis ), Warbling Vircos ( Vireo gilvus ), and Brewer's Blackbirds ( Euphagus cyanocephalus ). Avian species diversity in meadow habitats may be linked to moisture levels during specific times of the year. Diversity increased during the pre-migratory period of the dry year (1994) when compared with that of the breeding season, but was unchanged in the wet year (1995).     

Oribatid mite (Acari) community structure in steppic habitats of Burgos Province,central northern Spain

This work is a study of the communities of oribatid mites in steppic areas of Burgos Province, central northern Spain, in relation to different habitat types belonging to natural or disturbed ecosystems. The primary objective was to find the relationship between anthropogenic use of land and several diversity indices. Parameters such as abundance, species richness, real diversity (H′) and equitability (J′) of the mite communities were calculated in 20 soil plots, sampled in spring and autumn 2000, belonging to the predominant habitat types of this area: (1) cultivated lands, (2) abandoned crop lands, (3) grasslands/pastures, and (4) natural oak forests or a pine plantation. The most widespread species in the area as well as the most abundant taxa overall are documented, together with the faunistic checklist of oribatid mites identified in the study. The results show a general decline in the composition of the oribatid community, in terms of species diversity and abundance, from non‐disturbed soils to cultivated lands. The number of species (richness) was usually higher in forest soils than in disturbed ecosystems, in which the most degraded soils showed the lowest number of species. The community analysis shows the differences due to habitat type and ubiquitous bioindicator species.     

The influence of habitat features on amphibian distribution in Northeastern Greece

Environmental and isolation variables relating to abundance of breeding amphibians, species richness and community structure at different spatial scales were examined in the Dadia-Lefkimi-Soufli Forest National Park, Evros, Greece. Logistic regression and a generalized linear model were used to relate several habitat characteristics to species occurrence and species richness. The community structure responses to breeding-pond features were examined at four spatial scales using canonical correspondence analysis (CCA). The richest communities live in low-altitude ponds, with stony or clay bottoms, high solar exposure and abundant submerged and floating vegetation. The CCA models were significant (p < 0.005) and revealed the influence of altitude, percentage of field and broadleaf forest coverage, and number of water bodies on amphibian species assemblages at all four spatial scales. There is a specific need for holistic management of amphibians that will consider habitat connectivity, particularly between aquatic and terrestrial habitats, at a larger, more interconnected scale.     

Road edge effects on litter invertebrate communities of subtropical forests

We assessed road edge effects on leaf-litter macroinvertebrates in laurel and pine forests in Tenerife (Canary Islands), studying composition, abundance, richness and diversity, and the role of environmental gradients. We sorted species to the finest taxonomic resolution possible and used a morphospecies approach when necessary. In all, 15,824 invertebrates were identified from 388 litter samples (from >500 species, five major phyla and 31 orders). Alien invasive species of Oligochaeta, Pulmonata, Isopoda, Diplopoda and Hymenoptera were frequent in both forests. Richness, diversity and rarefaction pointed to a disturbance threshold within the first 10 m off the road, and edge effects were steeper in laurel forest than in pine forest. Overabundant aliens were partially responsible for highly disturbed litter assemblages on this edge zone in both forests. Proximity to road edge caused gradients of disturbance of forest structure. Litter moisture, rock and litter cover in laurel forest, and grass and canopy cover in pine forest were the best predictors of community variation. Results seemed to give some empirical support to the intermediate disturbance hypothesis. This altered road edge zone may accumulate regionally causing net reductions of ecosystem area and quality, impacting on its integrity and biodiversity.     

Diversity of Salticidae (Arachnida: Araneae) in the historical and natural reserve ‘Martín García Island’, Argentina

From Martín García Island were collected 975 jumping spiders, from five environments, using beating net and manual sampling methods. Saitis variegatus Mello-Leitão, 1941 was the most abundant (24.62%). The sandy xerophilous forest had the highest species richness (23 morphospecies) and jungle showed the greatest spider abundance (n: 384). The sandy area was the least diverse and the last in relative abundance. Salticids represented 16% of the species recorded from Argentina, and the second largest family registered. The spider fauna found could be similar to that of the Southern Brasilian region, as occurs with scorpions. Two genera and two species are new records for Argentina. In addition, three new species of jumping spiders, as well as the discovery of the unknown male and female of two species, were registered. There was no record of cosmopolitan spiders or those with a large distribution range on the Island.     

Habitat selection by small mammals in Brazilian Pampas biome

The use of microhabitats by small mammals was investigated in an area of Pampas in southern Brazil. We used 10 transect lines with 12 live-traps during six fieldwork sessions between June 2009 and April 2010. Sixteen environmental variables measured were summarized by a principal component analysis (PCA). Richness, total abundance and abundance of each species captured were correlated with the first two PCA axes. The environmental variables were also correlated with the small-mammal abundance through a canonical correspondence analysis (CCA). The first axis was related to variables that characterize forest environments, such as canopy cover and number of trees, and the second axis (with which the species richness and abundance were associated) was related to water, arthropods and herbaceous vegetation. The CCA and PCA showed a significant effect of microhabitat variables on species occurrence. In view of the great variability of environments in the study area and the correlation of the species with the environment variables measured, the degree of heterogeneity seemed to be an important factor associated with the small-mammal variation among microhabitats.     

The associated beetle fauna of Hohenbergia augusta and Vriesea friburgensis (Bromeliaceae) in southern Brazil

This work presents the first list of Coleoptera species found in Hohenbergia augusta (Vell.) E. Morren and Vriesea friburgensis Mez. (Bromeliaceae), in Santa Catarina state, Brazil, most of them identified to the species level. Beetle species richness and composition were compared between the bromeliad species and between Atlantic forest and restinga habitats. Biological information on some beetle species is reported for the first time. We also discuss the aquatic habit of the hydrophilid Lachnodacnum luederwaldti Orchymont, 1937 (Sphaeridinae) inside bromeliad phytotelms.     

Terrestrial isopods as bioindicators for environmental monitoring in olive groves and natural ecosystems

ABSTRACT

Terrestrial isopods (Crustacea: Isopoda: Oniscidea) are an important component of biodiversity as they constitute useful bioindicators for monitoring environmental quality in a variety of natural and agricultural ecosystems. In the present study, the predictive strength of several important components of biodiversity (e.g. herbaceous and woody plants, etc.) and agro-environmental factors for isopod species richness in each management system of olive groves and a natural ecosystem in central Greece was investigated. Our study highlights an increase in isopod species richness with increasing air humidity, woody plant species richness and soil organic matter in organic olive groves. It is noteworthy that woody plant species richness could be utilised as the best candidate for monitoring isopod species richness. In the conventional olive groves, isopod species richness decreases possibly due to herbicide and inorganic fertiliser application. In abandoned olive groves, isopod species richness increases with increasing soil plant litter and pH. Moreover, soil organic matter has been proved to be a positive indicator of isopod species richness in maquis ecosystems. The species Porcellio laevis can be regarded as an indicator for organic olive groves. Conclusively, this paper contributes to the integration of biodiversity conservation with ecologically sustainable agriculture, conservation of agroecosystem and natural ecosystem services and preserving landscape.     

Soil oribatid mite (Acari: Oribatida) diversity and composition in semi-deciduous forest fragments in eastern Amazonia and comparison with the surrounding savanna matrix

We recorded species abundance and richness of oribatid mites along 16 plots established in semi-deciduous forest fragments in Amazonia. The results were compared with a published dataset consisting of an inventory carried out in 38 plots in the surrounding savanna. Totals of 143 and 91 species were recorded in the forest fragments and savanna, respectively. Sørensen similarity index between both environments was 0.44. Ordination of sites according to oribatid mite species composition showed a clear separation between forest fragments and savanna. Rostrozetes ovulum, Archegozetes longisetosus and Eohypochthonius (Eohypochthonius) becki were abundant and frequent in the forest fragments but exceedingly rare in the savanna. Neoppia (Neoppia) schauenbergi, Pseudoppia sp. C, Microppia sp. A and Cosmochthonius sp. A were limited to the savanna. This study also represents an early step toward knowing which groups of species are exclusive to one or another vegetation type or are sensitive to their inherent environmental conditions.     

Impacts of nonnative plant species on production and diversity in the front range of Colorado

Nonnative plant species are considered one of the greatest threats to biodiversity, yet we still are unable to predict how production and diversity of a community will change once a species has invaded. Ponderosa pine woodlands in the Front Range of Colorado are ideal for studying the impacts of nonnative plants on production and species richness. We selected 5 sites along the northern Front Range with varying proportions of nonnative and native species and compared understory production and species richness along the gradient of nonnative species dominance. Total species production was positively and significantly related to total species richness, and total species production increased significantly with increasing nonnative species richness. There was a negative relationship between native and nonnative species production, and there was no relationship between nonnative species richness and native species richness. This study demonstrates the complex nature of species richness and productivity relationships and should serve as a starting point for future research in which a variety of other variables are considered.     

Microhabitat choice and differential use by anurans in forest streams in southeastern Brazil

The use of space by anuran amphibians during reproductive activities was studied at eight forest streams in the Reserva Particular do Patrimônio Natural Santuário do Caraça, southeastern Brazil. Identified microhabitats were classified into 18 types based on substrate and height above ground/water. A total of 440 individual anurans of 19 species was recorded in these microhabitat types. Electivity indices were calculated for the three most abundant species and indicated that specimens actively selected microhabitats. Species with broad niches (generalists) did not occur in more streams than species with narrow niches (specialists), and streams with higher species richness did not contain more specialists. Species showed high levels of overlap in microhabitat use, which were not related to the number of co‐occurring species. The distribution patterns observed in the studied anuran assemblages likely reflect specific reproductive preferences and colonization abilities rather than the result of competitive pressures.     

Effects of exotic grasses on soil seed banks in southeastern Arizona grasslands

Species richness in Madrean mixed-grass prairies dominated by native or exotic species in southeastern Arizona was characterized at the community and point scales using ten 1-m 2 quadrats nested within each of eight 1000-m 2 plots. In the 1000-m 2 plots average richness was significantly higher in oak savanna (OS, 121.0 species) than in exotic grassland on mesa tops (EMT, 52.0 species), whereas native grassland on mesa slopes (NMS, 92.5 species) and native grassland on mesa tops (NMT, 77.0 species) did not differ significantly in richness from OS or EMT. When richness was partitioned by life form, EMT was notably poorer than other community types in species of perennial grasses, perennial herbs, and summer annuals. In the 1-m 2 quadrats, OS (21.2 species), NMS (20.9 species), and NMT (20.7 species) were significantly richer than EMT (5.9 species). Cover in 1-m 2 plots was significantly higher in EMT than in NMT, NMS, or OS. Species richness at the point scale showed a unimodal relation to canopy cover, with cover accounting for 30% of the variation in number of species in 1-m2 quadrats. Competitive exclusion and allelopathy have perhaps limited species richness at the point scale in exotic grassland. There was no evidence of a species-pool effect between point and community scales, but such an effect between community and landscape scales was supported. Madrean mixed-grass prairies are landscapes with high species richness in comparison to other grassland types in North America, providing a large pool of potential colonizing species at the community scale. Beta-diversity (between communities) within the landscape of the Appleton-Whittell Research Ranch was consequently high despite a relative lack of habitat diversity.     

Land snail diversity in Wind Cave National Park, South Dakota

Eighty-two soil samples and additional hand-collection in Wind Cave National Park yielded over 2000 terrestrial gastropod specimens. The specimens represent 26 different species, including a South Dakota species of concern, Vertigo arthuri . New South Dakota state records for Gastrocopta pellucida and Vertigo tridentata were recorded. Samples from grassland habitats were less likely to contain snails and had lower species richness than samples from either forest or shrubland habitats. Canyons, creek beds, bases of limestone cliffs, and shrublands are important habitats for snails in the park.     

Cubitermes subarquatus termitaries as shelters for soil fauna in African rainforests

Most soil fauna in tropical rainforests require a pre-existing shelter for at least part of their life cycles. Among termites and ants, the most frequently encountered taxa, the availability of appropriate nesting sites is a major factor controlling the multiplication of colonies. Work carried out in five forests in southern Cameroon indicates that termitaries of Cubitermes subarquatus, whether active or abandoned, provide shelter for large numbers of invasive invertebrates, particularly ants and other termite species, and may be a determining factor in the patchy distribution of many taxa. Dissections of 90 termitaries (65 active, 25 abandoned) produced a great diversity of invasive fauna, including 354 ant colonies representing 75 species in 31 genera. Ants occurred in all abandoned termitaries but 6·1% of active termitaries had no ants present. Nevertheless, in total active termitaries sheltered more ant colonies (273) than did abandoned ones (81). Every termitary examined also sheltered founding pairs or incipient colonies of alien termites, but active C. subarquatus termitaries yielded fewer mature colonies of alien termites (56·9%) than did abandoned ones (84%).