Major Microhabitats Research Articles

A Multi-landscape Assessment of Leptospira Prevalence on a Diversity of Small Mammals.

Leptospirosis is a major zoonotic disease, especially in the tropics, and rodents were known to be carriers of this bacterium. There was established information on Leptospira prevalence among animal reservoirs in human-dominated landscapes from previous literature. However, there was very little focus given comparing the prevalence of Leptospira in a wide range of habitats. An extensive sampling of small mammals from various landscapes was carried out, covering oil palm plantations, paddy fields, recreational forests, semi-urbans, and wet markets in Peninsular Malaysia. This study aims to determine the prevalence of pathogenic Leptospira in a diversity of small mammals across different landscapes. Cage-trapping was deployed for small mammals' trappings, and the kidneys of captured individuals were extracted, for screening of pathogenic Leptospira by polymerase chain reaction (PCR) using LipL32 primer. Eight microhabitat parameters were measured at each study site. Out of 357 individuals captured, 21 (5.9%) were positive for pathogenic Leptospira of which recreational forest had the highest prevalence (8.8%) for landscape types, whereas Sundamys muelleri shows the highest prevalence (50%) among small mammals' species. Microhabitat analysis reveals that rubbish quantity (p < 0.05) significantly influenced the Leptospira prevalence among small mammals. Furthermore, nMDS analysis indicates that the presence of faeces, food waste, and exposure to humans in each landscape type also were linked with high prevalence of pathogenic Leptospira among the small mammals. This study supplements previous studies on pathogenic Leptospira prevalence across different landscape types, and the major microhabitat factors associated with Leptospira prevalence. This information is crucial for epidemiological surveillance and habitat management to curb the possibility of the disease outbreaks.

Differences in microhabitat and morphology of two sympatric congeneric species Palaquium maliliensis and Palaquium obovatum in the education forest of Hasanuddin University

Two species of Palaquium (P. maliliensis and P. obovatum) were found coexist in same habitat in the educational forest of Hasanuddin University (Unhas). Two or more species are living in a habitat could be formed from similar parent through genetic isolation process without geographic isolation and was classified as sympatric congeneric species. So far, sympatric congeneric species is still controversial among researchers. Based on this case, the purpose of this study was to determine the microhabitat and morphological differences between the two species. The methods of the study were conducted by purposively selecting 21 samples of P. maliliensis and 20 samples of P. obovatum at the tree level. In each samples found, the microhabitat characteristics (topographic position and slope) and morphological characteristics (leaf, buttress root, and morphological in general) were observed. Morphological measurement data were analyzed with correlation test for intra-species variable and real difference test for inter-species variable. This study concluded that the slope was one of the major microhabitat factors that has driven the process of sympatric speciation between P. maliliensis and P. obovatum. In morphological characteristics, differences between P. maliliensis and P. obovatum appeared in the form of leaves.

Microhabitat selection and distribution of functional feeding groups of mayfly larvae (Ephemeroptera) in lotic karst habitats

Research examining mayfly ecology in karst streams and rivers has increased in recent years, though microhabitat preferences remain poorly characterized. We examined mayfly assemblage taxonomy, functional feeding groups and microhabitat preferences in two contrasting lotic Dinaric karst catchments, one pristine and one anthropogenically impacted. At monthly intervals over a one-year period, all major microhabitats (i.e.dominated by boulders, cobbles, sand, silt, mosses, or angiosperms) were sampled at sites spanning springs, upper, middle and lower river reaches, and tufa barriers. In both catchments, mayfly species richness was comparable among microhabitats, while mayfly abundance was highest on mosses and lowest on silt. NMDS ordination did not group assemblages according to microhabitat type, which may reflect the greater influence of physical and chemical water properties. In both catchments and all microhabitats, mayfly assemblages were dominated by grazers/scrapers at upstream sites and by detritivores at downstream sites. Active filter feeders were more abundant in microhabitats with silt substrates and lower current velocities. This study demonstrated that certain mayfly species strongly preferred a specific microhabitat type, reflecting their water current preferences and feeding strategies, while other species shifted between microhabitats, likely in search of food resources and shelter. The results emphasize the importance of habitat heterogeneity in supporting diverse communities in karst rivers.

Nesting tree characteristics of heronry birds of urban ecosystems in peninsular India: implications for habitat management.

Wetland ecosystems, particularly the mangrove forest, are the primary wild habitat of heronry birds. However, urban ecosystems have become a favorite breeding habitat of these birds. To provide inputs into the habitat management for conservation of these birds, we investigated the quantitative and qualitative characteristics of nesting trees of heronry birds in the urban environment of the North Kerala region of peninsular India. Census on nesting trees was done in 3 major microhabitats of the urban ecosystem: avenues of national highways and towns, nonresidential plots, and residential areas apart from the mangrove islets in the peri-urban locality. The study found that 174 trees of 22 species hosted 1,928 heronry bird nests in the urban habitats; mangrove forests, although plentiful in the study area, hosted only about 20% of the total nests encountered in the study. Rain trees Samanea saman (43.7%) were the most available nesting tree. The greatest number of nests and nesting trees were encountered on the roads of urban areas, followed by nonresidential areas and residential areas. The differences in the observed frequencies of nesting trees in 3 microhabitats and in 3 types of roads (national highways > state highways > small pocket road) were significant. Canopy spread, girth size, and quality of the trees predicted the tree selection of the heronry birds in urban environments. Therefore, we recommend proper management and notification of the identified nesting trees as protected sites for the conservation of herorny birds.

Micro-habitats Utilizations, Feeding Niche Overlapping, and Management Systems Impacts on Community Tolerances of Wasp Species within Oil Palm Plantations.

A study on micro-habitats utilizations, feeding niche overlapping, and management systems impacts pertaining to hymenopteran community were evaluated at five chosen oil palm age stands within FELDA Sungai Tekam oil palm plantations, Pahang. Samplings were done within the duration of one year, employing the standard Malaise traps, starting from February 2013 till February 2014, involving both hot and wet seasons. 60 species, from 17 families and 35 subfamilies were successfully collected during the sampling periods. Eight defined micro-habitats were elaborated, with the subdivisions of major, minor, stable, and risky micro-habitat types. Management systems impacts were associated with the applications of chemical herbicides and fertilizers. Species groups were formed using Two-Way Hierarchical Cluster Dendrogram, following 75% of information remaining. Three species groups were formed for hot and wet seasons respectively, with the first group involved nearly half of the overall hymenopteran community. Beneficial nectariferous plants, heaps of chipped rotting oil palm trunks, and remnants of rotting forest logs were all the prominent micro-habitats associated will all cases of hymenopteran species groups, for both cases of major and minor micro-habitat types. Application of BASTA, Glyphosate-Type-A and Type-B herbicides, as well as NK-Mix, Borax, and GML chemical fertilizers were all highly correlated with hymenopteran species groups, showing the high tolerance of most hymenopteran species towards the employed management systems, with reference to minor micro-habitats. Strong feeding ecological niches and plexus values between species of similar species groups formed were specifically associated with discrete but connected minor micro-habitats with weaker food chains, collectively forming larger stable food webs within major micro-habitats. Suggestions on maintaining minor micro-habitats for the survival of most hymenopteran community, as well as the sustenance of their food sources were also discussed.

Micro-habitats Utilizations, Feeding Niche Overlapping, and Management Systems Impacts on Community Tolerances of Wasp Species within Oil Palm Plantations.

A study on micro-habitats utilizations, feeding niche overlapping, and management systems impacts pertaining to hymenopteran community were evaluated at five chosen oil palm age stands within FELDA Sungai Tekam oil palm plantations, Pahang. Samplings were done within the duration of one year, employing the standard Malaise traps, starting from February 2013 till February 2014, involving both hot and wet seasons. 60 species, from 17 families and 35 subfamilies were successfully collected during the sampling periods. Eight defined micro-habitats were elaborated, with the subdivisions of major, minor, stable, and risky micro-habitat types. Management systems impacts were associated with the applications of chemical herbicides and fertilizers. Species groups were formed using Two-Way Hierarchical Cluster Dendrogram, following 75% of information remaining. Three species groups were formed for hot and wet seasons respectively, with the first group involved nearly half of the overall hymenopteran community. Beneficial nectariferous plants, heaps of chipped rotting oil palm trunks, and remnants of rotting forest logs were all the prominent micro-habitats associated will all cases of hymenopteran species groups, for both cases of major and minor micro-habitat types. Application of BASTA, Glyphosate-Type-A and Type-B herbicides, as well as NK-Mix, Borax, and GML chemical fertilizers were all highly correlated with hymenopteran species groups, showing the high tolerance of most hymenopteran species towards the employed management systems, with reference to minor micro-habitats. Strong feeding ecological niches and plexus values between species of similar species groups formed were specifically associated with discrete but connected minor micro-habitats with weaker food chains, collectively forming larger stable food webs within major micro-habitats. Suggestions on maintaining minor micro-habitats for the survival of most hymenopteran community, as well as the sustenance of their food sources were also discussed.Â

Foraging and microhabitat use by crustacean‑feeding wrasses on coral reefs

Crustaceans are an important component of coral reef ecosystems, occupying a broad range of microhabitats, but achieving the greatest biomass in dead coral and coral rubble. These 2 microhabitats are therefore hypothesised to be focal foraging locations for crustacean-feeding fishes. The present study investigated the relationship between foraging in wrasses (Labridae), a major group of crustacean predators, and 5 major microhabitats on a coral reef: live coral, dead coral, coral rubble, sand and the epilithic algal matrix (EAM). Although the greatest biomass of crustaceans typically occurs in dead coral and coral rubble, crustacean-feeding wrasses displayed positive selection for a more diverse range of microhabitats. In contrast, sand and live coral were not positively selected by any taxa. The relationships between crustacean predators and their prey appear to be more complicated than previously assumed, and may be mediated by habitat structure, preferred prey, predation risk and behavioural and morphological adaptations.

Benthic Crustacea on coral reefs: a quantitative survey

Benthic crustaceans are an important component of the coral reef fauna, yet our understanding of their ecological significance is incomplete. To determine the community structure, abundance, biomass and productivity of benthic Crustacea at Lizard Island, a mid-shelf reef on the Great Barrier Reef, Australia, we investigated 5 major microhabitats: dead coral, coral rubble, sand, epilithic algal matrix (EAM) and fine-branching live coral. Crustacean communities differed significantly among habitats, with the exception of dead coral and coral rubble. Dead coral was the most important microhabitat type in terms of crustacean abundance (7838 ± 628 ind. 100 cm-2, mean ± SE), biomass (0.75 ± 0.13 g m-2, wet weight) and estimated productivity (0.17 ± 0.043 g 100 cm-2 yr-1 ash free dry weight). These values were 2 to 3 orders of magnitude greater than those for the least important habitats (EAM and fine-branching live coral). Despite their abundance, the average crustacean body length was just 0.79 ± 0.32 mm, largely due to the dominance of harpacticoid copepods. In contrast, decapods exhibited very low abundances, but yielded the greatest biomass and productivity and were particularly abundant in dead coral and coral rubble. The results highlight the importance of small crustaceans and dead coral microhabitats as valuable contributors to the trophic structure of coral reefs.

Forest Soil Heterogeneity and Soil Sampling Protocols on Limestone Outctops: Example from SW China

Forest soil heterogeneity of outcrop karst was studied by testing soil organic carbon at a selected 20 m × 30 m plot set up in Maolan primitive karst forest area, southern Guizhou Province, China. 90 microhabitats in the plot are roughly classified into 7 distinct microhabitat There was great heterogeneity in the plot not only for soil distribution but for great difference of soil organic carbon content. Soil organic carbon (SOC) contents were much higher, ranging from 40.1 g/kg to 203.5 g/kg. The CV (coefficient of variation) value of SOC from 38 soil sampling points, 22 sampling microhabitats, each microhabitat type, and individual microhabitat was 43%, 41%, 2.2% to 42%, 14% to 57.3% respectively. This showed high soil heterogeneity in terms of soil distributing pattern, size and soil organic carbon SOC content in outcropped karst. Different methods were applied to calculate SOC content in the plot. Small discrepancies suggested that the mixed soil samples collected from the major microhabitat types covering 95% soil distributing area were capable of representing soil nutrient status of the whole plot.

Habitat selection of the long‐nosed bandicoot, Perameles nasuta (Mammalia, Peramelidae), in a patchy urban environment

Abstract Habitat selection in an omnivorous marsupial, the long‐nosed bandicoot, Perameles nasuta Geoffroy, was investigated in an urban environment with both natural and highly modified habitats at North Head, New South Wales, Australia. Habitat use at both macro‐ and microhabitat scales was determined using live‐trapping, and P. nasuta was shown to be a habitat specialist at this site. At night, animals used open grass macrohabitats disproportionately more for foraging than other macrohabitats. Trap‐revealed macrohabitat use was supported by radiotracking three males. Lack of understorey and absence of leaf litter were the major microhabitat features affecting habitat choice, although soil type probably also had some effect. Open areas may provide a more abundant and/or accessible food supply for P. nasuta, although better manoeuvrability or increased visibility to detect predators may also be important. Diurnal nest sites, located using radiotracking, were primarily in dense scrub vegetation, often comprising introduced species of plants. The dependence of P. nasuta on: (i) dense undergrowth for diurnal nesting and temporary nocturnal sheltering; and (ii) open areas for foraging indicates the importance of conserving a mosaic of open and dense vegetation to ensure the continued persistence of this endangered population at North Head.

Positive and negative interactions between environmental conditions affecting Cercocarpus ledifolius seedling survival

We evaluated the balance between positive and negative effects of environmental conditions on first-year seedling survival of the tree Cercocarpus ledifolius during two summers, 1996 and 1997. The experimental design was fully crossed with two levels of water, with and without supplementation, two levels of herbivory, with and without protection, and three major microhabitats, open interspaces, under the canopy of Artemisia tridentata shrubs, and under the canopy of mature C. ledifolius trees. Effects of drought and herbivory on seedling survival depended on the year. Water supplementation and herbivory protection during the dry summer of 1996 (27.7mm) generally increased seedling survival. Additionally, survival tended to be greatest beneath C. ledifolius canopies. More important ecologically were the significant interactions. In 1996, water supplementation increased survival more with than without herbivory protection. The three-way interaction, treatment-microhabitat combination, was most important; by far the greatest survival was in the water supplementation and herbivory protection in the tree microhabitat. During the wet summer of 1997 (158.5mm), neither water supplementation, herbivory protection, nor microhabitat were significant as main effects. The water-supplemented and herbivory-protected treatment again combined to yield highest survival, but this time in open interspaces rather than beneath trees. Our study shows how the importance of individual limiting factors and the relative favorableness of particular microhabitats appear to change across years depending on environmental conditions.

On the patterns of abundance and diversity of macrolichens of Chopta-Tunganath in the Garhwal Himalaya.

A total of 3211 colonies of macrolichens, from twelve 50 m x 10 m plots distributed across four macrohabitat (vegetation) types between 1500 m-3700 m in the Chopta-Tunganath landscape of the Garhwal Himalaya, yielded 13 families with 15 genera and 85 species. Lobaria retigera stood out as a broad-niched generalist species with moderate levels of abundance in all the three major microhabitats, viz. rock, soil and wood across 83% of all the plots sampled, whereas Umbilicaria indica emerged as an abundantly occurring specialist confined to rock substrates. Heterodermia incana and Leptogium javanicum appeared to be rare members of the community as they were encountered only once during the field survey. Woody microhabitats turned out to be richer than rock and soil substrates for macrolichens. Amongst the macrohabitats, middle altitude (2500-2800 m) Quercus forest was richest in species and genera followed by high altitude (2900-3200 m) Rhododendron forest, higher altitude grasslands (3300-3700 m) and then the lower elevation (1500 m) Quercus forest. Species, genus and family level alpha- as well as beta-diversities were significantly correlated with each other, implying that higher taxonomic ranks such as genera may be used as surrogates for species thus facilitating cost- and time-effective periodic monitoring of the biodiversity of macrolichens. Dynamics of the diversity of lichen communities in relation to various forms of environmental disturbance including livestock grazing and tourism as dominant land use activities in the higher Himalaya need further research.

Variations saisonnières de la recherche alimentaire et partage des ressources par une guilde de passereaux insectivores

The foraging behaviour of a guild of insectivorous gleaning birds in relation to food availability was studied from October 1983 to August 1984 in a Larch (Larix decidua) forest of the Alpes Maritimes, Southern France. Seasonal changes occured through the winter, both in the use of microhabitats by the birds and in their searching behaviour. Resource partitioning between species was related to food availability in each microhabitat. The foraging behaviour of the various species on Larch twigs changed as food resources declined in abundance. The exploitation of this microhabitat by the Goldcrest (Regulus regulus) decreased rapidly, whereas blue tits (Parus caeruleus) and coal tits (P. ater) progressively changed their searching behaviour, using «perching» postures instead of «hanging». Microhabitat segregation at that time of the year was quite likely the result of differing morphological adaptations as it is the case for the Goldcrest. During the breeding season, microhabitat niche overlap significantly increased among guild members. However, this overlap was not caused by changes in food availability in the major microhabitats. It was due to (1) the growth of needles on Larch twigs, involving changes in food searching techniques of the guild species, and (2) to the change in food habits, from a granivorous to an insectivorous diet, of the willow tits (Parus montanus) when they were raising their young. A decrease of the competitive interactions for microhabitats between guild members can also result from a change in their spatial organisation ; the birds which form mixed-species flocks in winter time scatter into territorial breeding pairs during spring. Some interspecific segregation might also be imputable to interspecific territoriality.

Données préliminaires sur l’écologie des Termites

Nineteen species of termites have been found within the 1 Km2 reference quadrat of Fété Olé. Eight species (Bellicositermes bellicosus, Psammotermes hybostoma, Odontotermes smeathmani and five species of Trinervitermes) feed entirely upon grass material, whereas seven species are wood-eaters, three are fungus-growers and only three are humivorous. The distribution of the various species is undoubtedly influenced by soil conditions. Only four species are found in each of the four major micro-habitats (table II). The mounds of Bellicositermes bellicosus are conspicuous components of the local landscape. The density of living colonies reach 0.5/ha and the volume of earth used for mound-building averages 20-25 m3/ha. Population estimates for colonies of Bellicositermes bellicosus at various stages of growth are given in table IX. The standing crop biomass averages 4,750-5000, g/ha for Bellicositermes bellicosus and 750-900 g/ha for Trinervitermes trinervius (fresh weight). An estimate of the trophic impact of Bellicositermes bellicosus upon the grass cover has been attempted (table VIII). This species alone is able to consume at least 5.4 % of the grass produced in the quadrat as a whole. In the shallow depressions, where this termite is particularly abundant, it can consume up to 49.2 % of the grass produced. An attempt has been made to estimate the production of sexuals in two species : Bellicositermes bellicosus and Trinervitermes trinervius. The production of sexuals of these two species is respectively of 10,000 -20,000/ha (2,800 g/ha, fresh weight) and 15,000/ha (500 g/ha, fresh weight). Swarming takes place at different times of the year in different species : Rhino termitidae, Amitermitinae and Termitinae generally swarm at the beginning, and Nasutitermitinae at the end, of the rains.