Differences In Species Assemblages Research Articles

Fishing in the gene-pool: implementing trawl-associated eDNA metaprobe for large scale monitoring of fish assemblages

AbstractMarine biodiversity monitoring in the Mediterranean’s increasingly threatened ecosystems is crucial for effective ecosystem conservation and management. Here, we leveraged the Mediterranean International Trawl Survey program (MEDITS) to implement eDNA sampling through the recently tested ‘metaprobe’ procedure and characterize fish assemblages in three separate areas off the Italian coasts: Northern Adriatic Sea (NoAS), Ligurian and Northern Tyrrhenian Sea (LNTS), and Sardinian Sea (SaS). By combining the information from two homologous mitochondrial 12S metabarcodes––i.e., Elas02 and Tele02 targeting elasmobranchs and teleosts, respectively––we identified 108 species, over 60% of which overlapped with those caught by the trawl net. We produced an accurate reconstruction of fish community composition of the examined sites, reflecting differences in species assemblages linked with both geographic area and depth range. Metaprobe eDNA data consistently returned a biodiversity ‘bonus’ mostly consisting of pelagic taxa not captured through bottom trawl surveys, including rare and endangered taxa (e.g., elasmobranchs). Overall, the spatial characterisation of the assemblages across the surveyed areas was better delineated and more robust using eDNA metabarcoding than trawl data. Our results support the operationalisation of the metaprobe as a simple, inexpensive, versatile sampling tool, in association with pre-existing ship surveys, to overcome many of the limitations of marine data collection and strengthen marine management.

Monitoring vital signs: Wetland vegetation responses to hydrological resources in the Macquarie Marshes NSW, Australia

AbstractHuman intervention through damming, diversion and extraction of water resources has created regulated dryland river systems. As a result, connectivity between river channels and floodplain wetlands has diminished. Wetland function is fundamentally linked to water availability: flooding exchanges water, nutrients, sediments and biota with the floodplain. Water allocation for environmental flows may mitigate wetland degradation following river regulation by improving hydrological connectivity between rivers and floodplain wetlands. We report the results (2014–15 to 2018–19) of a vegetation monitoring program in the Macquarie Marshes in north western New South Wales. As part of the long‐term program, we monitored semi‐permanent wetland (Water Couch (Paspalum distichum) grassland or sedgeland dominated) and River Red Gum (Eucalyptus camaldulensis) forest/woodland communities along with environmental and water resource availability predictors. During the five‐year period, we found linear and nonlinear responses of functional group abundance and species richness to the water year and to time since last inundation. We also found differences in species assemblages in response to the flow and flooding regime, particularly water year and inundation duration. These results indicated that wetlands continued to express dry and wet phase responses. We also observed a depressed response to the large 2016–17 flood event by a subset of semi‐permanent wetland sites that had not been inundated in 3 years, compared with sites that were more recently inundated. This result indicated that environmental water management, along with protection of natural inundation events, may improve the resilience of floodplain wetlands: increased hydrological connectivity may promote a stronger wetland response when floods occur. Our results indicate that inundation, in part comprised of managed environmental flows, is a primary driver of species assemblage and functional group representation in semi‐arid floodplain wetlands.

Understanding patterns and pathways of exotic perennial grass invasion in South‐eastern Australian grassy communities

AbstractAimExotic perennial grasses (EPGs) are significant invaders of native grassy communities. We sought to determine how the profile of invading perennial grasses varies among different climatic regions and different grassy communities, to understand at which scale management is best undertaken. We investigated whether invader occurrence was related to specific plant traits.LocationNew South Wales, Australia.MethodField surveys of EPGs at 139 sites from nine grassy communities across four regions were assessed for variation in invasion profiles amongst regions and communities. We used a ranking of invasion risk based on plant characteristics to identify grasses likely to be more invasive and tested whether this ranking predicted the level of invasion in the survey.ResultsUsing multivariate analysis, we found that all communities were significantly invaded. These assemblages were distinct regionally, and for most plant communities. Five widespread invaders were established in all regions and communities. Invasion by pasture grasses (termed trade‐off species) was the most significant threat, coupled with capacity to develop long‐term seed banks and use allelopathy. Species with higher risk rankings were recorded in more sites, although a few grasses had much greater occurrences than their ranking predicted.ConclusionsGrassy communities across all regions were invaded by a suite of EPGs, some that have not been considered as problematic previously. Higher levels of invasion were associated with higher ranked species based on plant traits, indicating that our risk assessment is valuable as a management prioritization tool. Findings support community level management, although some species are important widespread invaders and could be managed at larger scales. Differences in species assemblages compared to nearby agricultural areas confirm different invasion pathways, with significant invasion from pasture grasses. Aided by the risk assessment tool, we propose that EPG management in native communities considers the climatic, community (including surrounding) and species level for prioritization.

Widespread homogenization of plant communities in the Anthropocene

Native biodiversity decline and non-native species spread are major features of the Anthropocene. Both processes can drive biotic homogenization by reducing trait and phylogenetic differences in species assemblages between regions, thus diminishing the regional distinctiveness of biotas and likely have negative impacts on key ecosystem functions. However, a global assessment of this phenomenon is lacking. Here, using a dataset of >200,000 plant species, we demonstrate widespread and temporal decreases in species and phylogenetic turnover across grain sizes and spatial extents. The extent of homogenization within major biomes is pronounced and is overwhelmingly explained by non-native species naturalizations. Asia and North America are major sources of non-native species; however, the species they export tend to be phylogenetically close to recipient floras. Australia, the Pacific and Europe, in contrast, contribute fewer species to the global pool of non-natives, but represent a disproportionate amount of phylogenetic diversity. The timeline of most naturalisations coincides with widespread human migration within the last ~500 years, and demonstrates the profound influence humans exert on regional biotas beyond changes in species richness.

Spatial trends of Potamogetonaceae along an altitudinal gradient

Studying the effect of altitude on species distribution may help us to predict the response of species to future climate changes, which will likely cause upward migration of vegetation zones. In this study, we aimed to analyze distribution and abundance patterns of Potamogetonaceae along an altitudinal gradient and to determine the species characterizing a priori defined five altitudinal groups. We included 294 sampling for 19 species from 141 wetlands across Turkey with an elevation gradient of 2700 m. Analysis of similarities (ANOSIM) found significant differences in species assemblages only between some altitudinal groups. Seven species were found in either high or low altitudes. Stuckenia pectinata had the highest contribution to all groups except one in analysis of similarity percentages. Detrended correspondence analysis revealed a clear altitudinal gradient by placing species under six clusters. Even widespread species occurring in all altitudes showed a tendency of altitudinal preference. The results were inferred from our physicochemical measurements for the species and relevant literature. Exclusively highland species were found in waters with similar physical and chemical properties (i.e. low electrical conductivity, salinity, and ammonium concentrations). However, lowland species were sampled from very diverse aquatic habitats. Among the lowland species Potamogeton acutifolius was found under low values for the above-mentioned physicochemical water parameters but Althenia orientalis showed extremely high values, as well as Potamogeton coloratus and Potamogeton nodosus. Understanding elevational distribution of macrophytes is especially important due to difficulties in their upward migration and availability of suitable aquatic habitats.

Temporal Variations of Micro Benthic Assemblage in the Sangu River Estuary, Bangladesh

Temporal distribution of shellfish assemblages, together with water quality data, was conducted in the Sangu river estuary of Bangladesh to assess shellfish's diversity index during winter, pre-monsoon, and monsoon and post-monsoon periods. A total of 15 species of shellfish belonging to 9 families was recorded of which  Acetes  sp. (25.18%),  Matuta victor  (18.77%),  Exopalaemon styliferus  (18.28%),  Parapenaeopsis sculptilis  (14.22%) were found to be most dominant species during the study period. Significant temporal differences were observed for water temperature, salinity, water transparency, P H  and DO. The diversity indices, Shannon-Wiener diversity index and Margalef richness index showed a significant difference among the seasons while no significant difference was observed in the Pielou’s evenness index and Simpson dominance index. The analysis of similarity (ANOSIM) was used to test for significant differences in species assemblages between sampling seasons. At the similarity of 74.8%, three groups were attained while winter and pre-monsoon showed separate clustering from other groups. The Non-metric Multidimensional Scaling (nMDS) showed 50% similarity in all seasons based on Bray-Curtis similarity matrix. The CCA ordination indicated that temperature was the most important environmental parameter shaping the shellfish assemblage structure.

A tale of two habitats: preliminary comparison of fish abundance and diversity between saltmarsh- and mangrove-dominated creeks in the Nahoon Estuary, South Africa

A preliminary assessment of abundance and richness of fishes utilising saltmarsh and mangrove habitats in the Nahoon Estuary, situated on the eastern coast of South Africa, was undertaken during July 2017. The structural composition and complexity of the two habitats were assessed and underwater cameras were used to provide preliminary insight into the use of the different habitats by fish taxa. The saltmarsh habitat had a higher fractal dimension and density of stems than the mangrove habitat. The species richness of fishes was slightly higher in the mangroves than in the saltmarsh, with nine and seven taxa recorded in the two habitats, respectively. The mean relative abundance of fishes was higher in the saltmarsh than in the mangroves and this was mainly due to the dominance of shoaling estuarine zooplanktivores in the saltmarsh. The mean relative abundance of estuary- associated marine fish species was, however, higher in the mangroves, which may be indicative of greater nursery use of this habitat by marine fishes. Although this is the first study to simultaneously assess the role of both saltmarsh and mangroves as fish habitat in estuaries of temperate South Africa, the findings are preliminary, and further study on seasonal differences in species assemblages is recommended.

The Influence of Canopy Cover on the Ecological Function of A Key Autogenic Ecosystem Engineer

Intertidal fucoid algae can function as ecosystem engineers across temperate marine regions. In this investigation, we assessed the function of the alga dominating rocky reefs in temperate Australia and New Zealand, Hormosira banksii. Invertebrate and algal species assemblages were examined within areas of full H. banksii canopy, areas where it was naturally patchy or absent (within its potential range on the shore) and areas where the intact canopy was experimentally disturbed. Differences in species assemblages were detected between areas with natural variation in H. banksii cover (full, patchy, negligible), with defined species associated with areas of full cover. Differences were also detected between experimentally manipulated and naturally patchy areas of canopy cover. Species assemblages altered in response to canopy manipulations and did not recover even twelve months after initial sampling. Both light intensity and temperature were buffered by full canopies compared to patchy canopies and exposed rock. This study allows us to predict the consequences to the intertidal community due to the loss of canopy cover, which may result from a range of disturbances such as trampling, storm damage, sand burial and prolonged exposure to extreme temperature, and further allow for improved management of this key autogenic ecosystem engineer.

Herbarium specimens reveal substantial and unexpected variation in phenological sensitivity across the eastern United States.

Phenology is a key biological trait that can determine an organism's survival and provides one of the clearest indicators of the effects of recent climatic change. Long time-series observations of plant phenology collected at continental scales could clarify latitudinal and regional patterns of plant responses and illuminate drivers of that variation, but few such datasets exist. Here, we use the web tool CrowdCurio to crowdsource phenological data from over 7000 herbarium specimens representing 30 diverse flowering plant species distributed across the eastern United States. Our results, spanning 120 years and generated from over 2000 crowdsourcers, illustrate numerous aspects of continental-scale plant reproductive phenology. First, they support prior studies that found plant reproductive phenology significantly advances in response to warming, especially for early-flowering species. Second, they reveal that fruiting in populations from warmer, lower latitudes is significantly more phenologically sensitive to temperature than that for populations from colder, higher-latitude regions. Last, we found that variation in phenological sensitivities to climate within species between regions was of similar magnitude to variation between species. Overall, our results suggest that phenological responses to anthropogenic climate change will be heterogeneous within communities and across regions, with large amounts of regional variability driven by local adaptation, phenotypic plasticity and differences in species assemblages. As millions of imaged herbarium specimens become available online, they will play an increasingly critical role in revealing large-scale patterns within assemblages and across continents that ultimately can improve forecasts of the impacts of climatic change on the structure and function of ecosystems.This article is part of the theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.

Sacred sites as habitats of culturally important plant species in an Indian megacity

Cultural ecosystem services related to urban green spaces contribute significantly to liveable cities. While previous studies highlight the intersection of cultural ecosystem services with societal values, spiritual or religious values associated with urban nature have received less attention. In India, as in other parts of the world, sacred sites are known for their biological richness, but analyses from urban sacred sites are largely missing. Based on a stratified random sampling approach, we analysed the cultivated and wild plant species assemblages of 69 sacred sites in the megacity of Bengaluru, India, in relation to biological and cultural features, and parameters related to the urban matrix and type of sacred sites (temple vs. katte). Unlike other urban studies, we found a dominance of native species in the cultivated and spontaneous species pools (121 species in total), with Ficus religiosa and Azadirachta indica as most frequently planted species. Culturally relevant species prevailed in the species pool (89%), with overlaps between religious (36%), medicinal (50%) and ornamental (62%) plants; only 11% of species were weeds. Urban matrix parameters (age of development, housing density) and size and type of sacred sites were related to differences in species assemblages. We identified key species for different classes of age and housing density, and for types of sacred sites. Our study demonstrates that urban sacred sites have an important potential in harbouring both native and culturally significant species that can support urban livelihoods in developing countries by a range of cultural and provisioning ecosystem services, including medicinal uses. As such sites are conserved by communities for spiritual or cultural beliefs, local biodiversity can be enhanced, e.g. by adapting management practices through community participation. This would strengthen the important contribution of sacred sites within the green infrastructure of rapidly growing megacities.

Long‐term phosphite application maintains species assemblages, richness and structure of plant communities invaded by Phytophthora cinnamomi

AbstractThe impact of the plant pathogen Phytophthora cinnamomi and the fungicide phosphite on species assemblages, richness, abundance and vegetation structure was quantified at three sites in Kwongkan communities in the Southwest Australian Floristic Region. Healthy and diseased vegetation treated with phosphite over 7–16 years was compared with non‐treated healthy and diseased vegetation. After site differences, disease had the greatest effect on species assemblages, species richness and richness within families. Disease significantly reduced cover in the upper and lower shrub layers and increased sedge and bare ground cover. Seventeen of 21 species assessed from the families Ericaceae, Fabaceae, Myrtaceae and Proteaceae were significantly less abundant in non‐treated diseased vegetation. In diseased habitats, phosphite treatment significantly reduced the loss of shrub cover and reduced bare ground and sedge cover. In multivariate analysis of species assemblages, phosphite‐treated diseased plots grouped more closely with healthy plots. Seven of 17 susceptible species were significantly more abundant in phosphite‐treated diseased plots compared with diseased non‐treated plots. The abundance of seven of 10 Phytophthora‐susceptible species was significantly higher along transects in phosphite‐treated vegetation. Comparison of the floristics of healthy non‐treated with healthy‐treated plots showed no significant differences in species assemblages. Of 21 species assessed, three increased in abundance and only one decreased significantly in phosphite‐treated healthy plots. In three Kwongkan communities of the SWAFR, P. cinnamomi had a profound impact on species assemblages, richness, abundance and vegetation structure. There was no evidence of adverse effects of phosphite treatment on phosphorus‐sensitive species, even after fire. Treatment with phosphite enhanced the survival of key susceptible species and mitigated disease‐mediated changes in vegetation structure. In the absence of alternative methods of control in native communities, phosphite will continue to play an important role in the protection of high priority species and communities at risk of extinction due to P. cinnamomi.

Predators and competitors of the mountain pine beetle Dendroctonus ponderosae (Coleoptera: Curculionidae) in stands of changing forest composition associated with elevation

Abstract The mountain pine beetle Dendroctonus ponderosae (Coleoptera: Curculionidae) is an irruptive tree‐killing bark beetle native to pine stands in western North America. The primary hosts are lodgepole and ponderosa pines. Recent rising temperatures, however, have allowed these beetles to survive at higher elevations more commonly than in the past, thus threatening whitebark pine, a keystone species of high elevation ecosystems and a highly susceptible host. The extent to which risk in whitebark pine stands may be mitigated by predators or competitors is unknown. We compared the communities of coleopteran predators and competitors of D. ponderosae in sites of varying elevation and species composition in Montana and Wyoming, U.S.A. Sites were selected for low to moderate levels of tree mortality, where the potential of natural enemies to prevent D. ponderosae from transitioning into outbreaks would be most relevant. Insect populations were evaluated using unbaited flight‐intercept panel traps and pheromone‐baited multiple funnel traps. Only the predatory beetle species Thanasimus undatulus (Coleoptera: Cleridae) was captured in these non‐outbreak stands. Based on the pheromone‐baited traps, predator load was higher at low‐elevation stands dominated by lodgepole pine than high‐elevation stands dominated by whitebark pine. Phloeophagous insects were more prevalent in the mid‐ and higher‐elevation sites, although most of the species captured would not likely compete substantially for resources with D. ponderosae. We also observed differences in species assemblages between the Montana and Wyoming sites, as well as differing utilities of baited and unbaited traps at low versus moderate tree mortality levels.

Tropical Rainforest and Human-Modified Landscapes Support Unique Butterfly Communities That Differ in Abundance and Diversity.

Tropical forests account for at least 50% of documented diversity, but anthropogenic activities are converting forests to agriculture and urban areas at an alarming rate, with potentially strong effects on insect abundance and diversity. However, the questions remain whether insect populations are uniformly affected by land conversion and if insect conservation can occur in agricultural margins and urban gardens. We compare butterfly populations in tropical secondary forests to those found in sugarcane and urban areas in coastal Guyana and evaluate the potential for particular butterfly communities to inhabit human-modified landscapes. Butterflies were sampled for 1 yr using fruit-baited traps in three separated geographical locations on the coast. We used nonmetric multidimensional scaling to assess differences in species assemblages and a generalized linear mixed model to evaluate abundance, species richness, evenness, and diversity. The secondary forests in all three locations supported higher butterfly abundance and diversity than other human-modified areas, although the magnitude of this effect varied by season and location. However, each land use supported its own type of butterfly community, as species composition was different across the three land uses. Sugarcane field margins and urban gardens supported populations of butterflies rarely found in our tropical secondary forest sites. Land management practices that encourage forest conservation along with butterfly-friendly activities in human settlements and agricultural areas could improve butterfly conservation. To this end, butterfly conservation in Guyana and other tropical landscapes would benefit from a shift from inadvertently to actively making the landscape attractive for butterflies.

Catastrophic wind and salvage harvesting effects on woodland plants

Compound disturbances may result in novel forest successional and developmental patterns. This study investigated effects of post-wind disturbance salvage harvesting, a unique compound disturbance of which the ecological consequences are unresolved, in fire-restored longleaf pine woodlands of the Alabama Fall Line Hills, a characteristically biodiverse and rare ecosystem. Plot-level data were collected May–June 2016 in areas undisturbed, wind-disturbed, and compound-disturbed (salvage harvested within seven months of an April 2011 EF3 tornado). Disturbance-mediated differences in (1) physical site conditions, (2) woody plant composition and structure, and (3) ground flora (herbaceous and woody plants≤1m in height) were assessed. Multivariate analyses revealed distinct differences in ground flora across disturbance categories. Biophysical drivers most correlated with differences in species assemblages included volume of coarse woody debris, sapling density, percent canopy cover, and basal area. Unharvested wind-disturbed plots had the greatest diversity of saplings and ground flora, and had indicator species with unique habitat requirements (specialists). Indicator species of compound-disturbed plots were mostly generalists that also had a relatively high frequency and abundance in the other disturbance categories. Reduced plant diversity on compound-disturbed plots was attributed to salvage harvest-mediated reductions in habitat heterogeneity and resource availability. Thus, leaving patches unharvested within salvaged stands is recommended to promote stand-scale plant diversity.

Low planktic foraminiferal diversity and abundance observed in a spring 2013 west–east Mediterranean Sea plankton tow transect

Abstract. Planktic foraminifera were collected with 150 µm BONGO nets from the upper 200 m water depth at 20 stations across the Mediterranean Sea between 2 May and 2 June 2013. The main aim is to characterize the species distribution and test the covariance between foraminiferal area density (ρA) and seawater carbonate chemistry in a biogeochemical gradient including ultraoligotrophic conditions. Average foraminifera abundances are 1.42 ± 1.43 ind. 10 m−3 (ranging from 0.11 to 5.20 ind. 10 m−3), including 12 morphospecies. Large differences in species assemblages and total abundances are observed between the different Mediterranean sub-basins, with an overall dominance of spinose, symbiont-bearing species indicating oligotrophic conditions. The highest values in absolute abundance are found in the Strait of Gibraltar and the Alboran Sea. The western basin is dominated by Globorotalia inflata and Globigerina bulloides at slightly lower standing stocks than in the eastern basin. In contrast, the planktic foraminiferal assemblage in the warmer, saltier, and more nutrient-limited eastern basin is dominated by Globigerinoides ruber (white). These new results, when combined with previous findings, suggest that temperature-induced surface water stratification and food availability are the main factors controlling foraminiferal distribution. In the oligotrophic and highly alkaline and supersaturated with respect to calcite and aragonite Mediterranean surface water, standing stocks and ρA of G. ruber (white) and G. bulloides are affected by both food availability and seawater carbonate chemistry. Rapid warming increased surface ocean stratification impacting food availability and changes in trophic conditions could be the causes of reduced foraminiferal abundance, diversity, and species-specific changes in planktic foraminiferal calcification.

Littoral benthic macroinvertebrate response to water‐level fluctuations in three reservoirs of the Willamette River Basin, Oregon

AbstractHigh‐head dams throughout the Willamette River Basin, Oregon create deep reservoirs that undergo inter‐seasonal and intra‐seasonal water‐level fluctuations (WLFs). The magnitude of WLFs is dependent on competing objectives of flood control, recreation, and water releases to maintain downstream habitat and facilitate migration of Endangered Species Act–listed salmonids. These reservoirs are drawn down to minimum conservation pool in winter, refilled to full pool by late spring and undergo variable WLFs, typically between 4 and 15 m, throughout summer. Here, we investigate the impact of seasonal WLFs on the density, biomass, and species composition of littoral benthic macroinvertebrates at Fall Creek, Hills Creek, and Lookout Point reservoirs. We sampled the submerged littoral zone during spring and summer using an adapted quadrat sampling method and assessed differences in species assemblages using a non‐parametric multivariate statistical technique. Descriptors of variation in substrate, WLF, temperature, and depth were incorporated to identify environmental variables associated with variation in assemblage composition. We hypothesized that density and biomass would decrease and assemblage composition would shift between seasons in response to WLFs. We found statistically significant differences in assemblage composition between seasons and among reservoirs, but density and biomass did not respond similarly. Observed variation in assemblages was associated with surface water temperature, water depth, substrate, and WLF. None of these variables alone explained observed variation. We provide evidence that seasonal WLFs influence macroinvertebrate assemblage composition and alter habitat characteristics. Our procedure effectively quantifies changes in species assemblages in impounded systems with low densities and dynamic littoral zones and can inform water management decisions with relatively modest costs.

Floodplain connectivity facilitates significant export of zooplankton to the main River Murray channel during a flood event

This study assessed the role that floods play in providing lateral connectivity between riverine habitats and floodplains, stimulating productivity and contributing zooplankton from the floodplain to the river channel. The study took place on the Chowilla Floodplain of the River Murray, Australia, and the adjacent River Murray Channel throughout the 2010–2011 floods. We found that a considerable transfer of zooplankton from the floodplain into the river channel occurred. Average zooplankton abundance was higher on the floodplain than the main river channel and increased the zooplankton abundance in the river channel downstream. At the peak of the flood, flows reached ~93 000 megalitres per day (ML d−1), inundating ~67 km2 of floodplain. At the time of this study, up to 6.3 ± 1.6 (SD) tonnes per day of zooplankton (dryweight) was being exported from the Chowilla floodplain. Differences in species assemblages were also observed within the River Murray, which seemed to be caused by the influence of the Chowilla Floodplain. This study demonstrated that floodplains provide significant zooplankton biomass, which constitutes a resource input into the riverine food web. These results provide some evidence for the Flood Pulse Concept, which highlights the importance of lateral hydrological connectivity between riverine habitats and floodplains in stimulating productivity and providing a linkage between habitats for biota. Management of regulated lowland rivers should consider not only the provision of water to the floodplain, but also the return of the floodplain waters to the river to sustain riverine food webs .

Restoration of Young Forests in Eastern Finland: Benefits for Saproxylic Beetles (Coleoptera)

AbstractEffective fire suppression in combination with intensive forestry has caused a large number of dead wood‐dependent (saproxylic) species to become threatened in Fennoscandia. In order to return the fire disturbance dynamics and to increase the amount of dead wood, restoration actions are urgently needed. We studied the effects of restoring young (under 30 years old) pine‐dominated (Pinus sylvestris L.) forest stands on saproxylic beetle assemblages in eastern Finland, focusing especially on rare, red‐listed, and pyrophilous (RRLP) species. Our experiment included a restoration treatment including two tree felling levels for fuel load (10 or 20 m3/ha) followed by burning, and an untreated control. We sampled beetles before restoration in 2005, during the year of restoration in 2006, and in two post‐treatment years in 2007 and 2011. Both restoration treatments increased the number of saproxylic and RRLP species. The species richness increased most in the year of restoration in 2006 and this trend continued in the following year 2007, but no differences in species assemblages were detected between the two fuel load levels. By 2011, however, the species richness and abundance had declined back to the pre‐treatment level. We suggest that restoration burning can also be directed to young forests where biodiversity values are initially low. On the basis of the observed decline in the species richness, we suggest that fire could be introduced in neighboring areas in approximately 5‐year intervals to maintain populations of the most demanding pyrophilous species.

Influence of surface water availability on mammal distributions in Nonggang National Nature Reserve, Guangxi, China

Surface water is a major limiting factor affecting animal activities in karst ecosystems. From March, 2006 to June, 2007 and from October, 2010 to May, 2011, infra-red camera traps were installed along animal trails and temporary rain pools in Nonggang National Nature Reserve, Guangxi, China, to monitor mammal diversity and relative abundance. In total, 19 species from 17 genera, 12 families, and 5 orders were recorded, including two State Key Protection Class I species, the François' langur (Trachypithecus francoisi) and Assam macaque (Macaca assamensis). Although 42% of species only occurred in one of the microhabitats, differences in species assemblages between trails and pools were not significant. The results of our observation indicated that camera trapping was effective in monitoring medium to large sized mammals, and for recording illegal hunting. In addition, our results suggest that authorities should reinforce patrolling, especially at water pools during the dry season, and eradicate unsustainable extraction of underground water. Moreover, based on the advantages of large inhibited environments to animal species, especially to large predators, we also recommend connecting the three isolated sections of the reserve to promote species recovery and dispersal.

Growth response of natural phytoplankton to enrichment of urea and other forms of dissolved nitrogen

The Broadwater of Myall Lakes, NWS Australia is brackish water which has a high variation in water quality in particular salinity and nutrient concentration. In these experiments, we determined the growth and species assemblages of natural phytoplankton community exposed to nutrient enrichment. Laboratory incubation condition was used to measure 10 days biomass and group-specific response of phytoplankton community. Four experimental occasions were conducted in autumn (April and May, 2005) and early summer (November and December, 2005) with two experiments each season. Biomass of phytoplankton was determined based on chlorophyll fluorescence, extracted chlorophyll a and cell abundance of phytoplankton, and community structure/species assemblages was based on manual identification until genus level using upright light microscope. During four experiment events, chlorophyll growth response was significantly higher in N+P treatment than control and N treatment only, with slow growth rate occurring 24 to 48 h following nutrient addition. There was an inconsistent trend of biomass in terms of cell abundance in respond to nutrient enrichment between experiment occasions, except for May experiment. Generally, our study found that the greatest difference of phytoplankton growth/biomass at the Broadwater of Myall Lakes was at site level instead of nutrient treatments. Our study also revealed that urea and other forms of dissolved N stimulated growth of group specific of phytoplankton, with P addition contributed considerably to changing in community structure of phytoplankton. The result of this study suggest that urea was not a factor for Cyanobacteria bloom as compared to the other dissolved N forms, consequently urea does not give a further enhance for Cyanobacteria bloom formation in The Broadwater of Myall Lakes system. This study revealed that enrichment of different forms of dissolved nitrogen stimulated the growth of phytoplankton taxa in ways that resulted in significant differences in species assemblages among treatments for most sites. Extra addition of P can initiate bloom conditions for cyanobacteria. In order to reduce this possibility, P flow from catchment areas has to be prevented. Key words: Phytoplankton, community structure, nutrient, urea