Total Species Richness Research Articles

Stable-isotope based trophic metrics reveal early recovery of tropical crustacean assemblages following a trawl ban

Abstract Trawl bans are relatively uncommon, particularly at the level of an entire coastal jurisdiction, and have seldom been studied in the tropics. A permanent territory-wide trawl ban has been implemented in Hong Kong coastal waters since the beginning of 2013. We used isotope-based metrics, in addition to traditional community measurements, to determine whether benthic crustacean assemblages had shown any signs of recovery three years after the trawl ban. We expected increases in species richness, abundance and biomass as well as shifts in trophic structure, including longer food-chain length (FCL) and greater trophic diversity after the ban. We further anticipated that carnivorous crustaceans would have higher mean trophic positions (MTPoC) at the assemblage level, and broader trophic niches at the species level. Sampling was undertaken at six sites in three regions (eastern, western and southern waters) before (in 2012) and after (in 2015) the ban. In general, there were no changes in assemblage total abundance or species richness after the trawl ban, but a decrease in biomass was observed. Isotope-based metrics showed that trophic niches of the crustacean assemblages were, however, broader at all sites after the ban. The FCLs at four sites in the eastern and western waters were longer after the ban, and three of them also showed increased MTPoC. In contrast, declines in FCL and other trophic metrics were recorded at the two southern sites. Among the five most abundant carnivorous crustaceans, all species at one eastern site, three at one western site, and four at three other sites expanded their trophic niches after the trawl ban; no changes were evident at the other eastern site where carnivores were scarce. By using isotope-based trophic metrics, we detected early functional recovery of the crustacean assemblages that cannot be revealed by traditional community analyses, implying that the effectiveness of the trawl ban would be underestimated if the assessment was based on community measurements only. We, therefore, advocate the use of isotope-based trophic metrics in tandem with the community measurements for more comprehensive assessments of ecosystem responses to anthropogenic disturbances and management interventions designed to alleviate them.

Aquatic Beetles (Coleoptera) of the University of Mississippi Field Station, Lafayette County, Mississippi, USA

Aquatic beetles in the families Dryopidae, Dytiscidae, Elmidae, Gyrinidae, Haliplidae, Helophoridae, Hydraenidae, Hydrochidae, Hydrophilidae, Noteridae, and Scirtidae were collected from the University of Mississippi Field Station (UMFS) in north-central Mississippi during May 2014 through August 2019. Located in the headwaters of the Little Tallahatchie River, UMFS encompasses 318 ha and includes over 200 ponds, springs, wetlands, and streams. We collected from mesocosms, ponds, and streams to survey the aquatic beetles of UMFS. In total, 103,113 beetles representing 132 species in 55 genera and 11 families were collected. We provide new state records for 24 species of Dytiscidae, three of Gyrinidae, three of Haliplidae, two of Hydraenidae, one of Elmidae, one of Helophoridae, one of Hydrophilidae, and one of Noteridae, with comments on the distribution, abundance, habitats, and life history of other species. Singletons represented 9.8% (13) of species collected. These data were used to estimate the total aquatic beetle species richness at UMFS and assess the effectiveness of mesocosm sampling in assessing a site's aquatic beetle richness.

Wild bee (Apiformes) communities in contrasting habitats within agricultural and wooded landscapes: implications for conservation management

Abstract Semi‐natural habitats are characterized by a high diversity of wildlife. However, other areas, e.g. old fields, can also play an important role in biodiversity conservation. We assessed the species richness, abundance, and diversity of wild bees (Apiformes), including species of various functional groups in two contrasting and differently managed landscape types. For this study, we selected 15 xerothermic or sandy grasslands or extensively managed fresh meadows located in agricultural landscapes as well as 15 old fields located in wooded landscapes. The study sites differed in area, stage of succession, and management regime. We did not detect any significant differences in total species richness, abundance, and diversity of Apiformes between the two landscape types, which suggests that both semi‐natural habitats and old fields are highly attractive to bees. The two habitat types, however, differed in species composition and proportions of functional groups. We found that in wooded landscapes, eusocial, hive‐nesting, and large‐sized species increased in abundance. The collected information on the preferences of Apiformes in respect of various habitats and landscapes makes it possible to protect and restore valuable habitats through the implementation of suitable methods of management, both locally and on the scale of landscapes.

Interpolated Altitudinal Species Richness in Arghakhachi District of Nepal

The magnitude of climatic variables over space and time determines the altitudinal variation of species richness. The present study has been carried out to determine the vascular plant species richness patterns along with altitude in the Arghakhanchi district (27° 45' to 28º 06' N and 80° 45' to 83° 23' E), West Nepal. The published literature related to the altitudinal distribution of vascular plant species in Arghakhanchi district was collected and enlisted a total of 597 species. The altitudinal range of the Arghakhanchi district was 200-2300 meters above sea level (masl) which was divided equally into 21 bands of 100 m each. The total number of vascular species that occurred at each 100 m contour elevation was considered as the species richness. The objective of this study was to find the vascular plant species richness pattern in Arghakhanchi district concerning altitude and climatic variables. The generalized linear model (GLM) was applied to the total species richness against altitude, annual mean temperature (AMT), and mean annual rainfall (MAR). Total vascular species richness showed a statistically significant unimodal pattern with a maximum richness of 471 species at 1300 masl (r2= 0.91; p < 0.001). Likewise, gymnosperm, dicot, monocot, and pteridophyte species richness showed a highly significant unimodal altitudinal richness pattern. Altitudes of modeled maximum species richness were found varied according to the taxa.

Contributions of temporal and spatial variation to the diversity of soil-dwelling testate amoeba assemblages in a swampy forest

Understanding the spatial and temporal variation in protist communities is essential for comprehensive studies on diversity and biogeography, yet most research focuses on either spatial or temporal processes, ignoring their combined effects. Here we use an additive partitioning approach to estimate the contribution of temporal and spatial components to the total taxonomical (morphospecies) diversity of testate amoebae in a swampy forest (the forest-steppe zone, Russia) during a snow-free season (from April to November). Testate amoebae have been chosen as model organisms for the study because they are a diverse and abundant group of protists that play important roles in soil communities mostly as consumers in decomposer food webs. Our results indicate that seasonality considerably contributed to the variation in the total species richness (γ) of both live and empty shell assemblages of testate amoebae (48 and 38 %, respectively). The beta component of species richness related to the spatial variation among sampling plots explained 22 % of γ-diversity in live assemblages and 28 % in empty shell assemblages. Beta diversity (both as species richness and species composition) decreased towards the end of the snow-free season. Spring assemblages were dominated by hydrophilous species of testate amoebae, whereas xerophilic species were more abundant in autumn. Our results imply that the snowmelt phase could be an important factor setting the heterogeneity of testate amoeba assemblages in the early spring, whereas in the rest of snow-free season the assemblages were considerably controlled by substrate moisture. Overall, temporal sampling is essential for adequate estimates of species diversity of soil-dwelling testate amoebae.

Traditional Agroforestry Systems and Conservation of Native Plant Diversity of Seasonally Dry Tropical Forests

Traditional agroforestry systems (TAFS), which integrate crops with wildlife, are important reservoirs of human culture and technical experiences with a high capacity for biodiversity conservation. Our study aimed to evaluate the capacity of TAFS to conserve the floristic diversity of tropical dry forests (TDF) in the Tehuacán-Cuicatlán Valley, Mexico. We compared TAFS and TDF by measuring their forest cover, floristic composition, and structure, in addition to documenting the motivations of people to maintain native vegetation in their agricultural fields. We conducted a restricted randomized sampling of perennial plant species, including nine sites of TAFS and nine of TDF to determine the alpha, beta, and gamma diversity. Furthermore, we conducted semi-structured interviews with peasants who managed the agricultural plots we studied. We also performed workshops with people of the communities where surveys were performed. Our findings show that TAFS can maintain, on average, 68% of the species (95% of them native to the region) and 53% of the abundance of individuals occurring in the adjacent TDF. TAFS harbour 30% (39 species) of plants endemic to Mexico. Total species richness of TDF and TAFS were similar, as well as the effective number of species or communities estimated for the alpha, beta, and gamma diversity, but differed in the abundance of individuals. The high species turnover recorded in TDF (72%) and TAFS (74%) has profound implications for conservation, suggesting that it would be necessary to maintain several sites in order to conserve the regional diversity of native vegetation. Material, non-material, and regulatory contributions were reported to be the reason that peasants take into account maintaining natural vegetation. TAFS associated with TDF in the region (also called “Apancles”) contain an important richness, diversity, and endemism of components of natural ecosystems, as well as provide multiple socio-ecological contributions. These systems could represent a viable alternative to reconcile biological conservation with social well-being.

Salvaging bycatch data for conservation: Unexpected benefits of restored grasslands to amphibians in wetland buffer zones and ecological corridors

The degradation and loss of habitats are one of the major causes of the recent global decline of amphibian populations, and wetland ecosystems are increasingly restored to counter these effects. However, there is little information on how restoration of non-wetland habitats such as grasslands affect amphibians in wet-terrestrial habitat complexes. We studied the spatial and temporal impacts of large-scale grassland restoration in wetland buffer zones and ecological corridors on amphibians in Hortobágy National Park (E-Hungary). We used bycatch data on amphibians inadvertently collected over seven years by Barber pitfall trapping in a post-restoration monitoring of invertebrates in restored and natural grasslands. Repeated measures analyses revealed higher abundance and species richness of amphibians from year 2 to 6 after restoration than in years 7 to 10. Early phases of restoration, dominated by weedy and dicotyledonous plants, provided suitable microclimatic refuges and foraging areas to amphibians. The availability of such microhabitats decreased in later phases of restoration, dominated by grasses and a few dicotyledonous plants. Legacy effects were important because fine-scale differences in crop history and seed mixture resulted in variation in total abundance and species richness. Space-for-time substitution analyses two and seven years after restoration also confirmed the temporal differences between early and late phases of restoration. Restored grasslands did not differ from natural grasslands in total abundance, species abundances or species richness of amphibians. Our study demonstrates that increasing the area of grasslands around and among lowland marshes can be an effective tool for conservation because amphibians readily use these areas as refuges or for foraging, movement, migration and dispersal. Restoration of non-wetland habitat can benefit amphibians at the local scale by extending suitable terrestrial habitats and at the landscape scale by establishing functional connectivity between wetlands.

Plant diversity and botanical composition in an Atlantic heather-gorse dominated understory after horse grazing suspension: Comparison of a continuous and rotational management

Floristic diversity changes substantially depending on the type of land management. We evaluated the impact of a continuous (CG) and rotational (RG) grazing system on the dynamics of plant diversity and community composition in a heather-gorse understory after a two and six-year pause from horse grazing. Previously grazed sites had higher total and rare species richness and diversity than ungrazed (UN), regardless the type of grazing system. The positive impact of previous grazing on species richness was higher in CG and continued after six years in both grazing systems. Seven species of high conservation interest in heathlands were present in the studied areas. Most of them were associated to CG management and none was exclusively in RG. The reduction of the shrub component by previous horse grazing led to a decrease of gorse dominance, thus potentially reducing fire risk and increasing plant diversity. The extent of the positive effect of horse grazing controlling excessive accumulation of combustible material and favoring species richness differed when relative abundance of species, and not solely the number of species, was taken into account (Simpson’s dominance increased and Pielou’s evenness decreased after six years). Overall, the effects of previous rotational and continuous grazing on plant diversity in an Atlantic heather-gorse dominated plant community were still apparent 2 or 6 years after grazing interruption, although declined after the six-year grazing interlude. Rotational management revealed a slight advantage upon the control of gorse biomass long term, and assisted to maintain the relative abundance of species more evenly over time. The alpha and beta diversity indices confirmed that plant diversity similarity between rotational and continuous management increased after six years.

An Efficient Tool for the Maintenance of Thermophilous Oak Forest Understory—Sheep or Brush Cutter?

Research Highlights: Thermophilous oak forests are among the most species-rich forest ecosystems in Central Europe. In the temperate zone, they evolved from mixed deciduous forests due to centuries-long livestock grazing. The abandonment of traditional forms of landscape use resulted in a constant decline in the number of patches of these communities, their area and species richness, which has been ongoing for decades and calls for their urgent conservation. The commonly used approaches to the conservation of this community are the reestablishment of grazing or mechanical removal of undergrowth. However, there are a limited number of works comparing their effects on the forest herb layer separately and in combination. Background and Objectives: The purpose of our research was to evaluate the effectiveness of grazing, mechanical brush removal and their combination for the conservation of the oak forest herb layer. Materials and Methods: Our work was based on a fully crossed experimental design set in a 60-year-old oak forest. The individual and combined influences of sheep grazing and brush cutting on forest floor vegetation were compared to control plots. We surveyed plant species twice—before the application of treatments and one year later on 600 one-square-meter subplots selected randomly in the limits of twelve fenced 20 m × 20 m treated and untreated study plots. Results: Both grazing by sheep and mechanical removal served well for total plant species richness and their cover, if applied separately. But these effects were not additive—plant species richness and plant cover on plots with combined treatment did not differ from plots, where just a single treatment was applied. Application of both treatments (but separately) had positive influence on species cover of the target group of plants typical to xerothermic oak forests and non-target species of mixed deciduous forests. Mechanical removal allowed also for successful control of woody species. Active conservation measures resulted also in negative effects—we observed increase in the species richness and cover of ruderal species on grazed plots. Conclusions: Both tested methods can be used for active conservation of open oak forest understorey vegetation. The method of active conservation should be chosen depending on the goal and the species composition of the forest floor and undergrowth found at the beginning of the restoration process, however, combining of these treatments does not bring any extra advantage. In our opinion a monitoring of the reaction of vegetation on treatments is of paramount importance.

Influence of tree species richness on tree growth and intrinsic water-use efficiency after drought in tree plantations in north-eastern Italy

Recent studies have highlighted that higher species richness can increase the resistance and/or the resilience to disturbances and stresses. The present study quantifies the overall tree species richness effect on growth and intrinsic water-use efficiency (iWUE) in three target tree species (i.e. Fraxinus excelsior, Juglans spp. and Prunus avium) after drought in six deciduous plantations in the Friuli-Venezia Giulia plain, North-eastern Italy. Planting densities, management, climatic and soil characteristics were the same at all the plantations. Stands differed only for their total surface area and for their total tree species richness (3, 4, 6, 7, 8 and 9). We double-sampled 15 dominant trees for each of the three target species, we measured tree-ring width, and we removed age-related trends using a detrending function. We selected 2006 as the driest year at the sites and 2014 as the reference year using the De Martonne Index. For both years, we measured δ13C signature in tree rings to calculate iWUE. Tree species richness had a positive effect on the response to drought both in terms of normalized ring width and iWUE, but only at a lower number of consociated species (< 5), when facilitation and/or complementarity mechanisms prevailed. Instead, negative responses were typical at higher levels (≥ 5), when competition was the dominant process within the stand. Moreover, species richness had no effect on tree growth in 2014, maybe because either competition or complementarity processes did not occur, or these processes could cancel out each other, when environmental conditions were not limiting.

Rotifera of various aquatic environments of Costa Rica in reference toCentral American rotifer fauna

Detailed surveys on rarely examined aquatic ecosystems often lead to the discovery of new species of high conservation value. This study directed towards the recognition of a variety of aquatic environments in Costa Rica 40 habitats, including lakes, wetlands, and small aquatic systems, e.g., ponds, ditches, puddles, tree holes, and bromeliads established the presence of 105 species of Monogononta representing 33 genera. In total, 91 species and 19 genera were found to be new for Costa Rica, including 29 species recorded for the first time in Central America e.g., Ascomorpha klementi, Beauchampia crucigera, Brachionus mirabilis, Cephalodella panarista, Filinia saltator, Horaella brehmi, Lecane amazonica, Lecane pawlowskii, Lepadella lindaui, and Mytilina acanthophora . The application of 2 estimates of total species richness allowed us predict that 70 new rotifer species may potentially be found in Costa Rica. Thus, we assume that only about 60% of the potential Costa Rican rotifer diversity was ascertained in our study. The most diverse genus was Lecane with 36 species. Among the most frequent rotifers there were some lecanid species, e.g., Lecane bulla, Lecane hamata, Lecane closterocerca and Lecane leontina, and also Colurella obtusa, Plationus patulus, Anuraeopsis fissa, and Platyias quadricornis.

Resilience of lowland Atlantic forests in a highly fragmented landscape: Insights on the temporal scale of landscape restoration

The Atlantic forest is one of the most threatened tropical forest ecosystem in the world, and despite current knowledge, its ability to recover structure and diversity after a disturbance is still a matter of debate. Quantifying carbon stocks and species diversity in forests at different successional stages and assessing their recovery capacity is important for designing local conservation and restoration strategies. We investigated the resilience potential of lowland Atlantic forests at landscape-scale using a chronosequence approach in 160 0.1-ha permanent plots, three old-growth and 13 second-growth forests at various stages of recovery. We assessed whether tree species richness, including species with high conservation values (endemic and threatened), composition and aboveground carbon stock recover along succession; and estimated how much of the old-growth forest values the 20-yr-old secondary forests had attained and the time needed to reach old-growth forests levels. Species richness, composition and carbon stock tended to recover along the chronosequence, while endemic and threatened species showed no relationship with forest age. After 20 yr of succession, the secondary forests recovered on average 52% of total species richness, 21% of species composition and only 16% of carbon stock of old-growth forests. We predicted that the absolute recovery of lowland Atlantic forests would take eight decades to thousands of years, much longer than the 10–40 years targeted by national efforts to restore degraded ecosystems. Despite slow recovery, these regenerating forests are important for climate mitigation and biodiversity conservation as they potentially sequester 1.78 Mg C ha−1 yr−1 and harbor a number of species comparable to old-growth forests. Our findings indicate that achieving landscape restoration and conservation goals through passive restoration can be a challenge, highlighting the need to invest in management plans in areas with relatively low resilience and high biodiversity and carbon conservation values.

Diversity and succession of riparian plant communities along riverbanks bioengineered for erosion control: a case study in the foothills of the Alps and the Jura Mountains

Soil bioengineering for riverbank stabilization involves the use of living plant materials to treat unstable or eroding riverbanks. These near-natural structures may harbor a higher plant richness and vegetation cover compared to classical civil engineering structures such as ripraps, but little information exists on vegetation dynamics during secondary succession on stabilized riverbanks. We hypothesized that soil bioengineering, by means of active introduction of early successional Salix shrubs, can foster successional trajectories of riparian plant communities, unlike civil engineering. We sampled three types of riverbank stabilization structures: pure bioengineering structures, mixed structures (combining riprap and bioengineering techniques) and ripraps, across a 14-year sequence on 42 sites located along 23 different streams running through the foothills of the Alps and the Jura Mountains (France and Switzerland). We quantified species richness and density and compared the temporal patterns of four groups of species that normally appear sequentially in natural succession on riverbanks (ruderal, hygrophilous, shade-tolerant, competitive species), as well as non-native species. Plant community composition differed greatly between ripraps and the two types of bioengineered sites, and ligneous species typical of advanced successional stages (Cornus sanguinea, Corylus avellana) spontaneously established in the oldest bioengineered sites. In general, richness of total species was higher in stabilization structures using soil bioengineering (including mixed structures) than in riprapped sites. In particular, the number of shade-tolerant and competitive species in bioengineered sites was double that found at ripraps after 14 years. Yet, richness of shade-tolerant species increased over time only on purely bioengineered sites, and their density there was almost twice that in mixed structures. Neither the type of stabilization structure nor time explained the variability in richness and density of non-native species across sites. Our study showed that along streams running through foothills, where erosion processes are usually intense, vegetation of bioengineered riverbanks exhibits successional dynamics similar to those theoretically found in natural conditions. Bioengineering can therefore foster ecological processes while stabilizing eroding riverbanks along foothill streams, thus satisfying human needs for infrastructure protection with less impact on the riparian ecosystem than riprap structures.

Untangling the determinants of macrophyte beta diversity in tropical floodplain lakes: insights from ecological uniqueness and species contributions

Deconstructing beta diversity patterns into site or species contributions is a modern approach to understand the factors affecting variation in biodiversity. In this context, estimating the Local Contribution to Beta Diversity (LCBD) and the individual Species Contribution to Beta diversity (SCBD) have been shown to be a good approach to improve knowledge of the drivers of beta diversity. We examined the beta diversity of macrophytes surveyed at 49 floodplain lakes in the Pantanal Wetlands in Brazil during the dry season. We found that, unexpectedly, total species richness was not correlated to LCBD values, but the number of rare species per site was possibly related to LCBD values. Three variables from Moran’s Eigenvector Maps (MEM), water transparency and organic matter were the main variables related to LCBD values. The species with highest contributions to beta diversity were those that occurred at approximately half of the surveyed sites. The same patterns were observed when analysing macrophyte data divided by life forms. Of the life forms, floating macrophytes contributed most to beta diversity. The understanding of which factors drive variation in LCBD and which kind of species most contribute to SCBD are fundamental to performing efficient conservation and restoration programs to maintain the structural, functional and ecological diversity of the macrophyte communities in dynamic floodplain ecosystems.

An annotated checklist of the Niphargidae (Crustacea: Amphipoda) of Greece.

Despite Greece being a global hotspot of subterranean biodiversity, its hypogean fauna is largely neglected from both an ecological and conservational point of view. An overview of the Niphargidae occurring in Greece is presented as an annotated list of all available published records. These records have resulted in an updated species list reflecting taxonomic corrections and species distribution range in the Greek peninsula. A total of 23 species, attributed to 3 genera, is up to date known from Greece with a high rate of endemicity found particularly in Crete. The endemic species of Greece amount to 21 (91% of total species richness), with the remaining species distributing also in the Republic of North Macedonia. Currently, none of them is listed in the national, European or global IUCN Red Lists of Threatened Species. Considering the increasing habitat degradation due to anthropic pressure, groundwater harvesting and climate change we could lose rare and endemic species without even acknowledging their existence.

Noncrop features and heterogeneity mediate overwintering bird diversity in agricultural landscapes of southwest China.

Farmland birds are of conservation concerns around the world. In China, conservation management has focused primarily on natural habitats, whereas little attention has been given to agricultural landscapes. Although agricultural land use is intensive in China, environmental heterogeneity can be highly variable in some regions due to variations in crop and noncrop elements within a landscape. We examined how noncrop heterogeneity, crop heterogeneity, and noncrop features (noncrop vegetation and water body such as open water) influenced species richness and abundance of all birds as well as three functional groups (woodland species, agricultural land species, and agricultural wetland species) in the paddy‐dominated landscapes of Erhai water basin situated in northwest Yunnan, China. Birds, crop, and noncrop vegetation surveys in twenty 1 km × 1 km landscape plots were conducted during the winter season (from 2014 to 2015). The results revealed that bird community compositions were best explained by amounts of noncrop vegetation and compositional heterogeneity of noncrop habitat (Shannon–Wiener index). Both variables also had a positive effect on richness and abundance of woodland species. Richness of agricultural wetland species increased with increasing areas of water bodies within the landscape plot. Richness of total species was also greater in the landscapes characterized by larger areas of water bodies, high proportion of noncrop vegetation, high compositional heterogeneity of noncrop habitat, or small field patches (high crop configurational heterogeneity). Crop compositional heterogeneity did not show significant effects neither on the whole community (all birds) nor on any of the three functional groups considered. These findings suggest that total bird diversity and some functional groups, especially woodland species, would benefit from increases in the proportion of noncrop features such as woody vegetation and water bodies as well as compositional heterogeneity of noncrop features within landscape.

Hiding in Plain Sight: Elopomorph Larvae Are Important Contributors to Fish Biodiversity in a Low-Latitude Oceanic Ecosystem

Leptocephalus larvae of elopomorph fishes are a cryptic component of fish diversity in nearshore and oceanic habitats. However, identifying those leptocephali can be important in illuminating species richness in a region. Since the Deepwater Horizon oil spill in 2010, sampling of offshore fishes in the epi-, meso-, and upper bathypelagic depth strata of the northern Gulf of Mexico resulted in 8982 identifiable specimens of leptocephalus larvae or transforming juveniles, representing 90 recognized and established species and an additional 36 distinctive leptocephalus morphotypes not yet linked to a known described species. Leptocephali account for ~13% of the total species richness of fishes collected in the offshore region. A new morphotype of Muraenidae leptocephalus is described. DNA barcoding of selected specimens has further expanded the determination of several leptocephalus morphotypes.

Mangrove or mudflat: Prioritising fish habitat for conservation in a turbid tropical estuary

Mangrove habitats are typically the focus of conservation efforts in tropical estuaries because their structural complexity is thought to support greater biodiversity and nursery function than unvegetated habitats. However, evidence for this paradigm has been equivocal in turbid tropical estuaries where unvegetated mudflats are also highly productive. The present study compared the community composition, biodiversity, nursery-role and commercial fish biomass in two mangrove habitats and one mudflat habitat in the Gulf of Paria, Trinidad. A total of 12 705 fishes, comprising 63 species from 26 families, were sampled in mangrove creeks, seaward mangrove fringe and the subtidal margin of an intertidal mudflat from June 2014 to June 2015. The composition of the creek and mudflat communities were distinct, while the community of the mangrove fringe more closely resembled the mudflat than the mangrove creeks. Mean species richness (MSR), total species richness (TSR) extrapolated from species accumulation curves, and juvenile species richness (JSR) were significantly greater in the mudflat (MSR = 11.4 ± 1.0; TSR = 75 ± 14; JSR = 9.1 ± 0.8) than mangrove creeks (MSR = 9.0 ± 0.5; TSR = 49 ± 3; JSR = 6.1 ± 0.4) and the seaward mangrove fringe (MSR = 6.4 ± 0.7; TSR = 58 ± 14; JSR = 5.2 ± 0.4). Meanwhile, Shannon Weiner diversity, juvenile fish abundance and commercial fish biomass were comparable between habitats. These findings caution against the generalisation that mangroves are the most important habitat for fishes in turbid tropical estuaries. There is now a growing body of evidence that mudflats warrant consideration as important repositories of biodiversity and nursery function for juvenile fishes.

Biodiversity and carbon sequestration potential in two types of tropical rainforest, Cameroon

Implementing Mechanisms for Reducing Emissions from Deforestation and Forest Degradation (REDD +) requires knowledge of the carbon storage potential in different forest types and different key reservoirs. We investigated the relationship between tree diversity and carbon stock in two forest types in Cameroon, an evergreen forest (EGF) in the South and a semi-deciduous forest (SDF) in the East. We aimed to characterize the two forest types, evaluate carbon stocks in five forest carbon reservoirs, and assess the relationship between the carbon stocks of the three pools (living carbon, dead carbon and soil carbon) studied and the diversity of the trees. An inventory of tree species with dbh ≥5 cm was made, covering 84 quadrats (25 m × 25 m), along 7 transects. Total woody biomass and dead wood were determined by allometric equations. We found that the EGF was more diverse in tree composition than the SDF. Absolute density and basal area were significantly higher in SDF than in EGF. There was a significant difference between living carbon of 327.35 t C.ha−1 in EGF and 369.77 t C.ha−1 in SDF. The contribution of dead wood in carbon storage varied on average from 8.40 t C.ha−1 in the EGF to 11.19 t C.ha−1 in the SDF. Similarly, trees of 5 cm ≤ dbh up to 10 cm dbh varied on average from 6.17 t C.ha−1 and 5.02 tC.ha−1 respectively for EGF and SDF. There was a positive but weak correlation between total carbon and tree species richness and a positive and moderate correlation between total carbon and biological types in both forest types. The results of this study highlight the need to take into account the assessment of carbon stocks of all reservoirs, and types of forests for a successful implementation of REDD + in the Congo Basin.

New Missouri Mayfly (Ephemeroptera) State and County Records

Seven mayfly species represent new state records, and an additional eight mayfly species represent new county records for Missouri. These 15 species from eight families increased the total Ephemeroptera species richness of the state to 110. Many species reported here include habitat specialists and large-river species collected as either larvae or adults. Homoeoneuria ammophila (Spieth) was collected from the Missouri River, a species having otherwise sparse records in North America, and the predacious, widespread Pseudiron centralis (McDunnough) was collected from the Mississippi River following an absence in Missouri records for over 65 years. Ongoing threats from land-use change and climate alterations make aquatic insect distribution records critically important. Greater sampling efforts should be concentrated in large-river habitats.