Wiener Diversity Index Research Articles

Dietary habits of the polkadot skate Dipturus chinensis in the East China Sea

We investigated the dietary habits of the polkadot skate, Dipturus chinensis (Japanese name: Gangi-ei), in the East China Sea by analyzing the stomach contents of 529 individuals. Of these, 18 (3.40%) had empty stomachs. The mean and maximum fullness indices (FIs) were 0.67% and 6.12%, respectively. The mean FI of female skates > 500 mm in total length (TL) was higher than that of males and smaller females. The most dominant prey category was crustaceans, which included shrimps, crabs, and anomurans, followed by fishes. Cephalopods were additionally observed. Dipturus chinensis fed on a wide variety of crustacean taxa, and among them, Caridea and Galatheidae were particularly common. Fishes that could be identified were mostly demersal fishes, such as Callionymidae, Triglidae, and Rajidae. Some juvenile D. chinensis were also observed, indicating that cannibalism occurs in this species. Even though dental sexual dimorphism was observed in large size classes (mainly > 500 mm TL), the diet of males and females significantly overlapped. Size-related dietary shifts from small crustaceans, such as shrimps and anomurans, to relatively fast-swimming prey, such as fishes, crabs, and cephalopods, were observed in all seasons. The composition of these prey categories varied among seasons. Shannon–Wiener diversity indices calculated for each size class ranged from 2.01 to 2.51, indicating D. chinensis are generalist predators. As size increased, trophic level increased from 3.58 to 3.85, indicating that larger specimens are at a slightly higher trophic level than smaller specimens. These results suggest that D. chinensis are middle-trophic-level generalist predators that utilize diverse prey depending on their size and the season, and thus play an influential role in the demersal ecosystem of the East China Sea.

Diversity of terrestrial isopod species in the Chambi National Park (Kasserine, Tunisia)

AbstractDiversity of terrestrial isopods across habitats and altitude was studied in the National Park of Chambi (central Tunisia). Samples were collected over five years in seven sites (S1–S7), within an altitudinal range from 750 to 1,500 m a.s.l. Twelve species belonging to five families were identified, with one endemic species (Porcellio djahizi) to this area, and three species were present in all sites (P. djahizi, Leptotrichus panzerii and Armadillidium tunisiense). Agnaridae represented by Hemilepistus reaumurii species was the most abundant family (58.77%) and found in only one site. Our results showed differences in species richness between sites. Indeed, S2 and S3 (900 and 1,050 m) showed the highest species richness with 11 species each. This result validates the hypothesis of mid‐elevational richness peak and contradicts the theory of large sampling regimes in determining the relationship between species richness and elevation. Terrestrial isopod species richness in the Chambi Mountain tends to decrease with altitude: 11 species in S2 and S3 to four species in S7. The highest Shannon–Wiener diversity index value was observed in S2 (H′ = 3.21 bits). Canonical correspondence analysis revealed that H. reaumurii was positively correlated with temperature whereas A. tunisiense and P. djahizi were the only species positively correlated with altitude.

The Study of Homegarden Agrobiodiversity, Practices of Homegardening and Its Role for <i>In-Situ</i> Conservation of Plant Biodiversity in Eastern Hararghe, Kombolcha Town Oromia Regional State Ethiopia

Homegarden plays a vital role for the livelihood of the people living in town. Homegarden agrobiodiversity was studied to highlight homegarden frequency, types, plant species, growth form and associated indigenous knowledge. The research was conducted during January to April 2017. A total of 180 randomly selected households were included in the survey. Ethnobotanical data were collected from purposively selected 60 homegardens using observations and semi-structured interviews while markets survey was conducted through structured questionnaire for homegarden products. Data were analyzed using descriptive and inferential statistics and similarity and Shannon wiener diversity index. The results indicated that 128 (71%) of the households were practicing home gardening. The homegarden plant composition gave 78 species belonging to 35 families. The representative families and number of species under each family were founded that the family Solonaceae, and Rutaceae rank top of the list (6 species) each followed by Fabaceae and Lamiaceae (5 species each) and Asteraceae, Poaceae, Rosaceae and Brassicaceae (4 species) each. Catha edulis, Lantana camara and Ruta chalepensis had the highest frequency of species followed by the families Asteraceae, Rutaceae and Poaceae. Catha edulis, Rhammus prinoides and Ruta chalepensis were among the families found in homegardens. It can be concluded that homegrdens of Kombolcha are rich in biodiversity. The present study showed the existing status of homegardens and local knowledge contribution to the farming systems in conservation of the biological diversity. In addition, plant species providing substantial benefits and factors combined to determining homegarden diversity are documented.

Preliminary Studies on the Occurrence and Abundance of Zooplankton Major Taxa in Keamari, Karachi- Backwaters

A preliminary study was conducted on the occurrence and abundance of zooplankton in the Karachi backwaters. Zooplankton sampling was conducted on monthly basis and the study was carried out on the basis of three seasons including pre-monsoon (January to May), monsoon (June to September) and post-monsoon (October to December) from a permanent station Napier Mole bridge (24o50’34’’.90 N, 66o59’17’’.55 E) during June 1996 to May 1998. The hydrographic parameters including air temperature (oC), water temperature (oC), salinity (ppt), dissolved oxygen (mg/L), pH, and transparency (cm) were recorded. Total 14 groups of zooplankton were recorded; hydromedusae, copepoda, mysids, amphipoda, acetes, lucifer, chaetognath, penaeid pl, caridean pl, zoea, megalopa, squilla larvae, fish larvae, fish eggs and others. Pre-monsoon season shows highest number of individuals and copepods were found to be the dominant group in all seasons. Zooplankton diversity, equitability and margalef index were measured seasonally. Highest shannon – wiener diversity index H' = (1.83), equitability E= (0.69) and margalef species richness Index d= (1.37) were measured in post-monsoon season. Statistical analysis (ANOVA) was performed in between seasons and zooplanktonic groups. No significant difference (at P>0.05, 0.148) was observed between zooplankton and seasons.

Diversity and structural composition of species in dipterocarp forests: a study from Fasiakhali Wildlife Sanctuary, Bangladesh

Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large, old Garjan (Dipterocarpus spp.) trees. The present study assessed composition, structure and diversity of the species in this protected area. A total of 32 trees species were recorded with DBH ≥ 11 cm belonging to 24 genera and 19 families. The forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance indices. Dipterocarpus turbinatus was the most dominant species with maximum relative density, frequency, dominance, and importance value index. Syzygium firmum and Tectona grandis followed in terms of dominance. The structural composition indicated higher number of individuals in the medium growth classes (41 to < 511 cm DBH and 16–20 m height ranges), whereas D. turbinatus was the only species that dominated most of the growth classes. Poor stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation, increased grazing and encroachments. This study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of Bangladesh. It will also contribute to identifying threatened plants to undertake D. turbinatus based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.

Temporal heterogeneity of prokaryotic micro-organism communities in sediment of traditional freshwater cultured fish ponds in Southwest China

ABSTRACTThe temporal heterogeneity of prokaryotic microorganism communities in sediment of traditional freshwater cultured fish ponds in Southwest China were investigated by 16S rRNA clone libraries. The result indicated that a total of 47 archaea clones and 392 bacterial clones were recovered from three samples, among them, the bacteria Mitsuaria chitosanitabida, Prolixibacter bellariivorans and Flavihumibacter petaseus and archaea Methanoregula formicica were dominant in the cultivation 1 year (Y1) sample, the bacteria Cetobacterium somerae, Allochromatium vinosum and Rhabdochromatium marinum and archaea Methanolinea tarda were dominant in the cultivation 2 years (Y2) sample, the bacteria Cetobacterium somerae and Bacteroides fragilis and archaea Methanolinea tarda were dominant in the cultivation 4 years (Y4) sample. The Shannon–Wiener (H) diversity index and the Simpson dominancy index respectively varied from 2.23 to 2.37 and from 7.30 to 9.04 for three gene libraries. Maximum operational taxonomic unit (OTU) richness was respectively estimated with two different models SChao1 and SACE, and it revealed SChao1 15 and SACE 15 for Y1, SChao1 15.25 and SACE 15 for Y2, SChao1 12 and SACE 12 for Y4. However, the B. fragilis which was found in the Y4 sample was 99% similar to the human and animal pathogen B. fragilis. No pathogenic organisms related to humans or animals were found at any other sample. Mentionable, the more detailed information about the safety of fish pond cultivation environment should receive more attention and further studies.

A rare temperate terrestrial orchid selects similar Tulasnella taxa in ex situ and in situ environments

Mycorrhizal symbiosis in orchids is unique in that fungal presence is considered a requirement for germination as well as for further development. Additionally, orchid fungal associations can exhibit high specificity in nature. Yet, an important ecological question remains unanswered: ‘With which orchid mycorrhizal fungi (OMF) do un-inoculated orchid seedlings form symbiosis when cultured ex situ?’ Simultaneously, it is asserted that orchid conservation efforts involving ex situ plant culture should exclusively utilize natural symbionts of the respective orchid taxa. We present a first comparison of OMF communities within the roots of asymbiotically cultured plants of the rare orchid Platanthera chapmanii grown ex situ (ES), and those occurring naturally in situ (IS). Nuclear ribosomal internal transcribed spacer (nrITS) barcoding region was used to identify peloton forming OMF from roots collected between 2012 and 2014 from both growing environments. Our 114 sequences clustered into 11 operational taxonomic units (OTUs) belonging to four closely related clades of the fungal family Tulasnellaceae. Shannon–Wiener (H) and Simpson diversity (D) indices were similar (p = 0.81 for both) for ES and IS OMF communities. Beta diversity comparisons also showed similarity between ES and IS treatments based on weighted (p = 0.10) and unweighted (p = 0.20) Bray–Curtis dissimilarity matrices. Bayesian and Maximum Likelihood (ML) phylograms clustered ES and IS derived fungal OTUs into the same clades. Our data suggest that P. chapmanii: (1) forms symbiosis with taxonomically similar fungi in ex situ culture and in its native soil, and (2) exhibits a narrow phylogenetic breadth of mycorrhizal fungal OTUs within the Tulasnellaceae.

Zooplankton diversity as indicators of pollution in warm monomictic Dal–Nigeen lake

The study aimed to assess the zooplankton diversity in Dal–Nigeen lake located in Srinagar, India. Zooplankton is a secondary producer which acts as the intermediate link between phytoplankton and fish in aquatic environment. Zooplankton diversity in the lake was monitored during autumn 2012 and summer 2013. Among zooplankton single species belonging to protozoa, 11 species to rotifera, 3 species to cladocera, and 2 species with single larval stage belonging to copepod were identified. Percent composition of zooplankton communities revealed that rotifera was the most dominant group followed by copepoda in summer, while rotifera was the most dominant group followed by cladocera in autumn season. The Shannon–Wiener diversity index (SWI) in summer varied from 1.29 to 3.63 and from 1.43 to 3.67 in autumn indicating moderate-to-good level of zooplankton diversity in the lake and low-to-medium impact of organic pollution from the anthropogenic activities. The study indicates that species abundance was lower in summer as compared to autumn season which may be due thereby to variation in environmental characteristics of the lake water.

Assessment of physicochemical water quality and phytoplankton diversity in Narikulam reservoir in Kanniyakumari district, Tamilnadu, India

Increase in human population and development causes adverse impact on ecosystems. Planktons are sensitive to different environmental conditions and good indicators of water quality. Study was carried out on phytoplankton and some physicochemical properties of Narikulam water reservoir during summer 2011. In the present study, phytoplankton density, diversity, compositions were considered for ecological monitoring and water quality assessment. Samples were collected from 12 different locations on two consecutive days. The identifications, compositions and diversity index analyses were carried out in the laboratory. Five phytoplankton groups were identified in the water samples comprising 48 genera. Chlorophyceae, Cyanophyceae, Bacillariophyceae, Euglenophyceae and Dinophyceae were found in the decreasing abundance. Shannon–Wiener Diversity Index (SWI) values varied from 1.97 to 3.78, with one outlier indicating moderate to good levels of phytoplankton diversity. No remarkable organic pollution was indicated by Palmer’s Pollution Index (2–12) in reservoir. The study revealed that Narikulam water reservoir was apparently unpolluted and free from adverse environmental conditions; therefore, water was suitable for domestic use and irrigation.

Lentic and lotic assemblages of zooplankton in a tropical reservoir, and their association with water quality conditions

Zooplankton assemblages in relation to water quality parameters at lentic and lotic habitats of Air Itam Reservoir, Penang, Malaysia, were analysed. Five sampling stations were designated, including three stations located in the reservoir (Stations A, B, and C) and two stations in the upstream inflow and downstream outflow (Stations D and E, respectively). The most common and dominant zooplankton found in the lake were Polyarthra vulgaris, Ceriodaphnia cornuta, Mesocyclops leuckarti, and Thermocyclops crassus. Water Quality Index, calculated as recommended by the Malaysian Department of Environment, ranged between 88.46 and 93.6, showed that the reservoir was clean. Low numbers of species and value of the Shannon–Wiener Diversity Index were recorded at stations located upstream and downstream of the reservoir. Cluster analysis based on the abundance of zooplankton species distinguished the sampling stations into two groups (lentic and lotic groups, comprised of Stations A, B, and C; and Stations D and E, respectively). This study showed that zooplankton occurrence and abundance were associated with the quality of their environment, and zooplankton community provides information about the reservoir ecosystem, thus reflecting the importance of biomonitoring in lake assessment and management.

Rice straw decomposition affects diversity and dynamics of soil fungal community, but not bacteria

Straw decomposition increased amounts of soil organic carbon and changed microbial biomass. But the different impacts of rice straw decomposition on the succession of bacterial and fungal community composition in field conditions were poorly understood. The objective of this study was to investigate the development of soil bacterial and fungal communities during rice straw decomposition in field conditions, and the relationship between soil chemical/physical properties and the evolution of microbial communities. A 1-year field study (90, 180, 270, and 360 days) was conducted, including the straw decomposition soil and control (no straw decomposition soil). The bulk soil samples (0–15-cm depths) from three replicate plots per treatment were collected for the analysis of soil properties and of microbial diversity parameters. Soil bacterial and fungal community structures and population sizes were determined by applying PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR). The bacterial and fungal community diversity was evaluated using the following parameters: Shannon–Wiener diversity index, richness, and evenness. Moreover, the relationship between soil properties and the changes of microbial communities was analyzed using redundancy analysis (RDA). The results showed that, in contrast to bacteria, the soil fungal population size and diversity indices were significantly increased during different time points of rice straw decomposition, and reached to the highest value at 360 days. When compared with the bacterial DGGE profiles, the fungal DGGE profiles significantly changed between the straw decomposition soil and control, and the dominant soil fungal genera varied apparently. Bacterial 16S ribosomal RNA (rRNA) and fungal 18S rRNA gene sequences obtained from the main DGGE bands were further sequenced, among which Penicillium sp., Aspergillus sp., and Acremonium sp. have the ability to degrade cellulose. RDA suggested that the soil available P, organic C, pH, and bulk density were the main factors influencing the variation in the fungal community structures and diversities. The fungal community structures displayed distinct successions during rice straw decomposition. But such finding was not observed in bacterial communities. The ratio of fungi to bacteria measured by qPCR was higher in the straw decomposition soil compared with the findings in control, indicating that fungi predominated in straw decomposition. Especially, our study deduced that the diversified cellulolytic fungal genera highly enriched in rice straw decomposition soils had great potential of mining novel cellulose-decomposing enzymes.

Integrated trophic position decreases in more diverse communities of stream food webs

The relationship between biodiversity and ecosystem functioning is an important theme in environmental sciences. We propose a new index for configuration of the biomass pyramid in an ecosystem, named integrated trophic position (iTP). The iTP is defined as a sum of trophic positions (i.e. the average number of steps involved in biomass transfer) of all the animals in a food web integrated by their individual biomass. The observed iTP for stream macroinvertebrates ranged from 2.39 to 2.79 and was negatively correlated with the species density and the Shannon–Wiener diversity index of the local community. The results indicate a lower efficiency of biomass transfer in more diverse communities, which may be explained by the variance in edibility hypothesis and/or the trophic omnivory hypothesis. We found a negative effect of biodiversity on ecosystem functioning.

Anthropogenic noise reduces bird species richness and diversity in urban parks

Anthropogenic noise is becoming more prevalent in the world and has been shown to affect many animal species, including birds. The impact of such noise was measured in Neotropical urban parks to assess how the noise affects avifauna diversity and species richness. We sampled bird species, and concurrently measured sound pressure (noise) levels (Leq, equivalent noise levels) in eight urban green areas or parks located in a large city (Belo Horizonte) in south‐eastern Brazil over a 1‐year period. The diversity of sampled points was measured by means of total species richness, Fisher's alpha and Shannon–Wiener diversity indices. Noise levels within all parks were greater than those in natural areas. We found that an increase in noise levels and the area of open habitats surrounding sampling points were negatively related to species richness. Social factors reflecting increased urbanization, such as higher incomes, were also negatively correlated with bird species richness. However, noise was the factor that explained most of the variance. These results suggest that anthropogenic noise can have a significant negative impact on the conservation value of urban parks for bird species.

Studies on ecology, fish diversity and fisheries of Ken–Betwa rivers (India): Proposed for inter-linking

The Ken and Betwa rivers traversing through Central India are the major tributaries of the river Yamuna. Both rivers originate above 550 m above sea level in the Vindhya region. An interlinking project proposed for the rivers envisages diversion of water from Ken basin to the Betwa. The river sediment is alkaline and dominated by sand (78–89%) in both rivers. Oxygen-rich alkaline water and moderate values of chemical parameters show the pollution free and productive nature of both the rivers. There was no statistically significant difference in water quality between the Ken and Betwa rivers, except for total alkalinity. The biotic parameters were observed in similar ranges and moderate condition. A total of 61 planktonic forms were recorded from the rivers out of which 55 were phytoplankton. For the first time, 89 fish species belonging to 10 orders, 26 families, and 62 genera have been recorded in the river Ken, while 81 species classified under 10 orders, 24 families, and 55 genera were found in the Betwa. Exotic fish species were also observed in the downstream stretches of both rivers. Out of the total fish species, 77 were common to both rivers, 12 were found only in the Ken River, and 4 species were restricted to the Betwa. Analysis of relative abundance showed dominance of Labeo boggut in the Ken and Osteobrama cotio in the Betwa River. On comparison of the Shannon–Wiener Diversity and Evenness Indices of fish diversity, these indicated slightly higher values in the Ken (3.76 and 0.842) than the Betwa (3.66 and 0.835). A total of nine near-threatened fish species was recorded in the rivers. Both rivers have already been obstructed by many developmental projects; the proposed interlinking would further negatively impact the ecology and fisheries.

Diatom communities in thermo-mineral springs of Galicia (NW Spain)

The species composition of diatom assemblages was studied in five unpolluted thermo-mineral springs in Galicia (NW Spain). Three are considered hot and two cold, and some contain hydrogen sulphide. A total of 68 taxa (24 genera) have been recorded. The Shannon–Wiener diversity index (H′) ranged between 0.63 and 2.01. The nMDS ordination showed that diatom assemblage composition was influenced mostly by conductivity, temperature and hydrogen sulphide concentration. Diatom assemblages found in the Galician springs differed from those in springs of other geographical locations with similar physical and chemical characteristics. The most species-rich genera were Nitzschia and Achnanthidium with 10 and 8 species, respectively. Achnanthidium exiguum and Achnanthidium saprophilum had the widest distribution. Denticula thermalis and Achnanthidium caledonicum were found in environments with relatively low mineralization and low temperature, whereas Rhopalodia gibberula, Rhopalodia operculata and Fragilaria crotonensis were found in mineral-rich springs with high temperatures. Achnanthidium exiguum, A. saprophilum, Achnanthes coarctata, Achnanthes exigua var. elliptica, Mayamaea atomus, Eunotia implicata, Gomphonema minusculum, Gomphonema minutum and Cosmioneis pusilla were present in the spring with high H2S content.

Diversity of Wild Bees along Elevational Gradient in an Agricultural Area in Central Java, Indonesia

Increases in mean temperature affect the diversity and abundance of wild bees in agricultural ecosystems. Pollinator community composition is expected to change along an elevational gradient due to differences in the daily ambient temperature. This study investigated the diversity and abundance of wild bees in an agricultural area along an elevational gradient in Central Java, Indonesia. Wild bees were collected using a sweep net in 40 green bean (Phaseolus vulgaris) cultivation sampling locations at seven different elevations (8, 108, 224, 424, 644, 893, and 1017 m above sea level). Species diversity was determined using the Shannon–Wiener diversity index. We identified 932 individuals from 8 species of wild bee belonging to 3 families. The family Apidae was predominant, with 6 species, while only 1 species was found from each of Megachilidae and Halictidae. Across the study sites, diversity increased with increasing elevation (H′= 1.4,D= 0.25, andE= 0.78 at low elevation toH′= 2.04,D= 0.13, andE= 0.96 at high elevation), and higher numbers of species were found at middle and high elevations. Species richness and abundance increased linearly with increasing elevation, and species diversity was highest at middle elevations.

Benthic mollusc assemblages in West Antarctica: taxa composition and ecological insights

Although different studies in Antarctica have dealt with benthic communities, few studies have focused on molluscan assemblages and their ecology. During the austral summer of 2011, 17 stations between depths of 68.5 and 754m were sampled in West Antarctica using a demersal bottom trawl pilot net on board RV ARA Puerto Deseado. In all, 1848 specimens of shelled molluscs were recorded. Gastropods were the most diverse group (species richness=74) and bivalves were the most abundant (n=1344). Shannon–Wiener diversity index values ranged between 0.58 and 2.99, with great variation at different stations. Cluster analysis using the Bray–Curtis coefficient showed three distinct assemblages types: one dominated by suspension feeders; a second with representatives from different trophic groups, including suspension feeders, grazers, scavengers, predators and deposit feeders; and a third, more differentiated, with few taxa and dominated by deposit feeders. Finally, multivariate analysis suggests that bivalves were more sensitive to temperature, whereas gastropods were more sensitive to depth.

Investigation of phytosociological parameters and physico-chemical properties of soil in tropical semi-evergreen forests of Eastern Himalaya

The study of floral diversity in forest and its development are incomplete without taking consideration of plant-soil interactions. So with this view in mind, the present study was conducted in tropical semi-evergreen forests of the Mokukchung district, Nagaland, in eastern Himalaya. The aim of the study was to investigate the phytosociological parameters in relation to soil properties. Seven sites were randomly selected to study the soil properties at up to one meter in depth and a phytosociological study was carried out in nearby areas via the quadrate method. In the studied sites, the richness of tree species varied from 4 to 15 ha−1, with Gmelina arborea and Duabanga grandifloras being the common species. The highest total basal area was recorded in 10 mile village (47,998.16 cm2 ha−1) followed by Minkong village site (32,704.66 cm2 ha−1). Soil physical and chemical properties—i.e. bulk density (BD), soil pH, organic carbon (OC), available nitrogen (N), available phosphorus (P), and available potassium (K) were analyzed using standard procedures. Significant differences were observed in the soil properties. The basal area of species showed significant positive correlation in terms of available K (0.754) and OM (0.302) content in soil, and the Shannon–Wiener diversity index (H) is also positively correlated with the available N content (0.402). The undisturbed nature of the sites played an important role in maintaining the soil fertility and floral diversity of the sites. Moreover, sites with maximum productivity and soil fertility are considered as potential carbon sequestration areas in the region while sites with the low soil fertility need restoration.

Above-ground arthropod community structure and influence of structural-retention management in southern Patagonian scrublands, Argentina

Southern Patagonia’s landscape hosts several semi-natural habitats, traditionally used for sheep production, such as Mulguraea tridens and Lepidophyllum cupressiforme scrublands. Mulguraea scrublands are managed via mechanical shredding to remove shrubs and increase grass availability, alternating with structural-retention strips. We analyzed the influence of structural-retention management (with cut and retention strips) in Mulguraea scrublands with regards to above-ground arthropod community structure, as well as differences between the two natural scrubland types. We worked in Santa Cruz Province (Argentina) with pitfall traps during two summers in the first 2 years after mechanical shredding. Richness, abundance, occurrence frequency, Shannon–Wiener diversity and Pielou evenness indices, and similarity among assemblages were evaluated using univariate and multivariate statistical tests. Complementarily, we described vegetation ground cover and microclimate. We collected 3279 individuals from 38 species belonging to Insecta and Arachnida Classes. Shannon–Wiener diversity and Pielou evenness indices, as well as the overall assemblages, differed significantly between managed cut strips and natural Mulguraea scrublands, mainly due to the loss and introduction of species from surrounding environments; abundance also differed in the first sampling year compared to the second year. Likewise, managed retention strips allowed the partial maintenance of arthropod community structure and had a microclimate that was similar to natural Mulguraea scrublands, although assemblages in managed cut and retention strips became more similar among themselves in the second sampling year. On the other hand, richness, abundance and assemblage of both natural scrubland types differed significantly, with 87 % more indicator species in Mulguraea than in Lepidophyllum scrublands. Greater dissimilarity occurred between both natural scrubland types in dryer years, which could be related with an El Nino Southern Oscillation event. If arthropod community structure changes prove stable over time, mechanical shredding with structural-retention management would allow for an increase in the sheep carrying capacity, while reducing impacts to the arthropod community, thus providing a viable compromise between productivity and conservation in a fragile arid environment. More studies are necessary to evaluate long term changes in above-ground arthropod community structure of scrublands in arid zones of southern Patagonia.

Effects of soil and climatic factors on arbuscular mycorrhizal fungi in rhizosphere soil underRobinia pseudoacaciain theLoessPlateau,China

We explored arbuscular mycorrhizal fungi (AMF) in the rhizosphere soil underRobinia pseudoacaciaL.,Leguminosae (black locust), and evaluated the relations between their diversity and soil and climatic factors in the semi‐aridLoessPlateau of northwestChina. A total of 23AMFspecies were identified at six sites. Of these, six belonged to the genusFunneliformis(Glomeraceae), five toRhizophagus(Glomeraceae), three toGlomus(Glomeraceae), two toAcaulospora(Acaulosporaceae), two toClaroideoglomus(Claroideoglomeraceae), two toSeptoglomus(Glomeraceae), one toAmbispora(Ambisporaceae), one toScutellospora(Gigasporaceae) and one toSclerocystis(Glomeraceae). The species that occurred in the largest proportion of soil samples wereRhizophagus intraradices(75%) andFunneliformis dimorphicum(66.7%). Soil‐available potassium was positively correlated with mycorrhizal colonization and species richness. Spore density was negatively correlated with soilpH, whereas theShannon–Wiener diversity index was positively correlated with total potassium. Most of the soil and climatic factors measured affected theAMFindices directly rather than indirectly. The relative abundances of 13AMFspecies were strongly affected by precipitation, temperature, total nitrogen, ammonium nitrogen and available potassium. This suggests thatAMFspecies are diverse andFunneliformiswas the most common and dominantAMFgenus in the rhizosphere soil under black locust in theLoessPlateau. Precipitation directly affectedAMFstatus and diversity in this distinctive semi‐arid ecosystem.HighlightsAnalysis of the effects of soil and climatic factors on mycorrhizal colonization andAMFdiversity of black locust.Improved understanding ofAMFcommunities and their function in soil under black locust.Precipitation was the strongest direct factor that affectedAMFin the semi‐arid region.Funneliformiswas the most commonAMFgenus in rhizosphere soil under black locust.