Species Accumulation Curves Research Articles

Effects of high‐carbon wood ash biochar on volunteer vegetation establishment and community composition on metal mine tailings

Pyrolyzed organic waste, also known as biochar, is commonly used as a soil amendment and has recently been promoted to remediate metal mine tailings by increasing substrate pH, enhancing water and nutrient retention, and reducing bioavailability of toxic metals. Bottom ash from bioenergy facilities can contain high levels of charcoal residue, and thus qualify as a type of biochar according to international standards; the availability of this material at low costs makes it of particular interest in the context of tailings remediation. Naturally recruiting vegetation is critical in areas of primary succession such as mine tailings, and thus understanding vegetation responses on these substrates is essential. We examined responses of naturally regenerated “volunteer” vegetation to additions of high‐carbon wood ash biochar at a range of application rates (from 0 to 30 metric tons [t]/ha) at two gold mine tailings sites in northern Ontario, Canada over a 2‐year period. Volunteer vegetation cover increased with biochar dosage, peaking at 10–20 t/ha. Wood ash biochar amendments altered substrate physical properties (pH, electrical conductivity [EC], bulk density, total carbon [TC], and nitrogen [TN]), but effects varied by site and with dosage. Substrate TC and EC increased significantly with dosage at both sites with highest measures detected in the 10–20 t/ha amendment range. Species composition showed site‐ and dosage‐specific responses to biochar additions; however, species accumulation curves consistently showed peak species richness at intermediate dosages in both sites and both years of growth. Observed changes in volunteer vegetation suggest that low to moderate dosage applications of high‐carbon wood ash biochar can be highly beneficial for revegetation of mine tailings, but that wood ash impurities can result in deleterious effects at high dosages. Results from these field experiments demonstrate the potential of wood ash in tailings restoration and incentivizes additional in situ experiments to further discern site‐specific mechanisms.

Diversity, abundance, and conservation status of woody species in a West African dry forest

AbstractThis study presents data on woody plant species richness and diversity of an inaccessible dry forest of Tula Mountains Woodland (TMW) located in the northeast of Nigeria. TMW supports a minimally disturbed mosaic of dry forest‐woodland. We sampled woody species in 190 plots of size 0.01‐ha, spaced 50 m apart on series of line transects. We found a total of 133 woody species belonging to 88 genera and 39 families in 1.9 ha area sampled in total. Out of 133 species, 120 were identified to species level, and 113 were recorded as trees, shrubs and lianas with diameter at breast height (dbh) ≥ 5 cm. Species accumulation curve was non‐asymptotic. Fisher's logseries model suggests that the plots sampled in the dry forest communities of TMW are represented by a high number of rare species. Of 120 identified species, 46 (38%) lacked evaluation on conservation status by IUCN. Out of 74 (62%) evaluated species, 2 were listed as critically endangered, 3 were vulnerable, and 69 were of least concern. In the TMW, 27% of woody species were restricted to Sudanian savannah biome, 61% occurred in Sudanian and Zambezian savannah biome. TMW serves as refugia for native plant species and plant communities in northeastern Nigeria.

Birdlife, a tourist attraction for the southern portion of Bacalar Lagoon, Quintana Roo, Mexico.

The Bacalar Lagoon (BL) in Quintana Roo, Mexico; is an area of high interest due to its tourist potential. However, the changes in landuse patterns, urbanization, extensive cattle ranching and rapidly expanding agriculture, have generated negative impacts on areas of adjacent plan communities and wildlife habitats. The objective of this study has to evaluate the level of vegetation conservation in the southern portion of the BL through the avifauna present in sites with contrasting degrees of conservation. Additionally, change "and their habitat preference(s) in the different communities" to and their habitat use preferences in the different communities. To evaluate the level of conservation of the BL, field visits and botanical collections were carried out to identify species. For the counting and identification of birds, monthly surveys were made through coastal tours along the cenote Xul-ha in 2.5 km transects. Four transects were established: two for sites characterized as semi-conserved and two with disturbed sites. A total richness of 40 taxa was observed, which corresponds to 8.1% of the Quintana Roo avifauna and 32% to wetland birds (125 species). The species accumulation curves indicated that semi-conserved and disturbed sites tend to reach asymptotes and with a coverage percentage greater than 90%. In terms of diversity and community structure, no significant differences were observed. However, the semi-conserved and disturbed sites each have 11 unique species and share 18 species. The LB has an intermediate diversity of bird species compared to studies at the Mexican level, the habitat is important for the conservation of birdlife; as it functions as a reservoir of diversity. Strategies has been suggested that promote sustainable tourism, support the restoration of natural vegetation; and facilitate the economic development of the region.

Diversity of benthic diatoms in the Baltic Sea: alpha and beta diversity, environmental drivers, and diversity-biomass relationships

Benthic diatoms are crucial for the functioning of ecosystems, but their diversity patterns along large gradients are poorly studied. By using 3 self-collected data sets along large environmental gradients in the Baltic Sea, represented over spatial scales of 60, 1300, and 2300 km, I investigated whether different aspects of diversity follow general patterns or are context- and region-specific. General diversity patterns along different gradients would likely indicate high resilience of benthic diatoms against differences and changes in the environment, whereas context-dependent patterns would possibly suggest that environmental change is likely to modify diatom communities and that region-specific differences should be considered when designing ecosystem management. I investigated the effect of environmental conditions on taxonomic and functional diatom diversity with distance-based redundancy analyses, variability of taxonomic diversity with species accumulation curves, taxonomic and functional aspects of spatial beta diversity with pairwise Bray-Curtis dissimilarity indices and Mantel tests, and diversity-biomass relationships with generalized linear models. The effect of environment on diatom communities was context-dependent, and different factors controlled communities along different gradients. Diversity varied along gradients and correlated with salinity in a U-shaped way. Beta diversity followed a general pattern of high taxonomic but low functional beta diversity along all gradients. Relationships between diatom diversity and ecosystem biomass were weak along all gradients. These results suggest that although the regional diversity of diatoms seems resilient, environmental change is likely to modify the local diversity of diatom communities. Finding out how these changes will affect ecosystem functioning requires further investigation.

Molluscs along a salinity gradient in a hypersaline coastal lagoon, southern Gulf of Mexico

Abstract Molluscs are a diverse phylum in coastal lagoons because the numerous taxa collectively display broad ranges of optima and tolerance with respect to ambient conditions. We report on the taxonomic composition, habitat preferences and feeding guilds of molluscs from Río Lagartos coastal lagoon, Mexico. Molluscs were collected in the rainy season (September/October 2017), during the winter (Nortes) season (February 2018) and at the end of the warm, dry season (May 2018). Samples were taken using a Ponar dredge, a cylindrical PVC core barrel, or a beach seine. We studied the abiotic characteristics (sediment grain-size distributions, submersed aquatic vegetation abundance and salinity) to explore assemblage differences across the broad salinity gradient that characterizes the system (~30–78 PSU). Molluscs were represented by 39 species, 34 genera, 23 families and two classes. Stenohaline species were more numerous overall than euryhaline species, but their occurrence in samples was low (<20% of the samples). Stenohaline taxa lived primarily in environments characterized by marine salinity, and few were found under hypersaline conditions. We collected a smaller number of species than did studies carried out in the lagoon >35 years ago. Species accumulation curves revealed that the full species richness was not captured in our study. Euhaline environments displayed greater mollusc species richness and had a larger proportion of amount (mass) of submersed aquatic vegetation. In the hypersaline environments, species richness may be favoured by the lower dominance of sands. Suspension feeders were the most diverse group in both the euhaline and hyperhaline environments.

Understorey species distinguish late successional and ancient forests after decades of minimum human intervention: A case study from Slovenia

The main species composition drivers in temperate deciduous forests are environmental conditions, a stand's age and the site history, e.g., the succession stage and past land use, as well as disturbance regime and current management. We compared plant species diversity and composition in late successional and ancient forests, co-occurring on the same small river island applying species accumulation curves and nonmetric multidimensional scaling, respectively. Given the island's geomorphological characteristics, we expected these to be very similar before human intervention in the past. The forests experienced differing disturbance regimes in the past, while over the last 30 years, human intervention has been the same and reduced to a minimum. The ancient forest in this study had two major characteristics defining it as old, mature forest: continuity of presence for more than 200 years and specific composition. The late successional forest experienced major disturbance in the 20th century and was allowed natural regeneration by bordering on the ancient forest, representing a potential species pool, and by decades of minimum human intervention. Our results showed that, even though there was no difference in species richness, we could still detect differences between the forests, particularly in the abundance and species composition of the understorey, among which geophytes had the most indicative importance. To make our results useful on a broader scale, we composed from the literature a species list of plants indicative for ancient forest and tested its application. These results are important for distinguishing between old and mature secondary stands and particularly for identifying old forest stands, which should be conserved and, in the case of fragmented landscapes, included in a network connecting forest fragments.

Diversity of duckweed (<i>Lemnaceae</i>) associated yeasts and their plant growth promoting characteristics

<abstract> <p>The diversity of duckweed (<italic>Lemnaceae</italic>) associated yeasts was studied using a culture-dependent method. A total of 252 yeast strains were isolated from 53 duckweed samples out of the 72 samples collected from 16 provinces in Thailand. Yeast identification was conducted based on the D1/D2 region of the large subunit (LSU) rRNA gene sequence analysis. It revealed that 55.2% and 44.8% yeast species were Ascomycota and Basidiomycota duckweed associated yeasts, respectively. Among all, <italic>Papiliotrema laurentii</italic>, a basidiomycetous yeast, was found as the most prevalent species showing a relative of frequency and frequency of occurrence of 21.8% and 25%, respectively. In this study, high diversity index values were shown, indicated by the Shannon-Wiener index (<italic>H′</italic>), Shannon equitability index (<italic>E<sub>H</sub></italic>) and Simpson diversity index (<italic>1-D</italic>) values of 3.48, 0.86 and 0.96, respectively. The present results revealed that the yeast community on duckweed had increased species diversity, with evenness among species. Principal coordinate analysis (PCoA) revealed no marked differences in yeast communities among duckweed genera. The species accumulation curve showed that the observed species richness was lower than expected. Investigation of the plant growth promoting traits of the isolated yeast on duckweed revealed that 178 yeast strains produced indole-3-acetic acid (IAA) at levels ranging from 0.08–688.93 mg/L. Moreover, siderophore production and phosphate solubilization were also studied. One hundred and seventy-three yeast strains produced siderophores and exhibited siderophores that showed 0.94–2.55 activity units (AU). One hundred six yeast strains showed phosphate solubilization activity, expressed as solubilization efficiency (SE) units, in the range of 0.32–2.13 SE. This work indicates that duckweed associated yeast is a potential microbial resource that can be used for plant growth promotion.</p> </abstract>

Comparative Diversity of Bats in Two Contrasting Habitats in Terengganu

Differentiations in the habitat and resource utilisation lead to segregation and specialisation of niches for bats within the structurally complex tropical rainforest in Malaysia. This research aims to characterise chiropterans’ assemblages found in two different habitat types in Tasik Kenyir (dipterocarp forest) and Setiu (oil palm plantation). A total of 48 sampling nights were conducted within two years period from March 2017 to March 2019 which covered four sampling sites in Tasik Kenyir and four sites at Setiu. Two standard four-bank harp traps and 10 mist nets were deployed throughout the study at every site to capture bats at understory levels. This makes a total of 576 sampling efforts for both areas. Song Meter SM2bats and Echo Meter Touch from Wildlife Acoustic were used to record the echolocation of insectivorous bats. The total number of individuals and species observed were used to determine species diversity, richness, and evenness. Paleontological statistic software was used to generate the rank abundance and species accumulation curves. Bray-Curtis similarity index was used to generalise the index that represents the relative abundance of the sampling sites. A total of 835 individuals comprising 31 species from six families were captured at both study areas. Out of 835 individuals, 695 were captured within Tasik Kenyir comprising 27 species from six families (H = 2.381) while 140 individuals were captured in Setiu comprising 20 species from five families (H = 2.40). The diversity of bats in Tasik Kenyir was hypothesised to be higher than in Setiu as the habitat possess a larger undisturbed forest. However, the result showed the opposite in which no significant difference was detected from the diversity index calculated between these two areas. Detailed studies need to be conducted to determine if some areas are used as transient habitats for bats.

Nectarivore butterflies (Lepidoptera: Papilionoidea) from an Urban Forest Fragment in Manaus, Amazonas

Lepidoptera is a diverse and abundant group of insects, widely used in biodiversity and conservation studies, as it has great social appeal. From this perspective, this study was aimed to conduct a survey of flower – visiting butterfly species in Bosque da Ciência, at the Instituto Nacional de Pesquisas da Amazônia (INPA), an urban forest fragment open to public visitation in the State of Amazonas, Brazil. Thus, attractive plants for nectarivorous butterflies were observed, and the best location and conditions for viewing such diversity, as well as a guide for their identification was proposed. Forty-three species of flower – visiting butterflies were identified, among which Anthoptus epictetus (Fabricius), Ascia monuste (Linnaeus), Anartia jatrophae (Linnaeus), Eurema albula (Cramer) were observed to be more frequent. According to the species accumulation curve, the species richness of butterflies would be higher if greater collection effort were employed. The period of greatest flight activity and flower - visitation occurred from 9 am to 11 am. Of the six attractive plants identified, Stachytarpheta cayennensis (Rich.) and Lantana camara L. were the most visited, so we consider that these species are important for butterfly attractiveness. The butterflies of Bosque da Ciência are a representation of the nectarivores guild of the city of Manaus, Amazonas, and the establishment of an attractive butterfly garden in this place can contribute to the promotion of environmental education by stimulating the knowledge and awareness for biodiversity preservation.

Disentangling the Drivers of the Sampling Bias of Freshwater Fish across Europe

The Wallacean shortfall refers to the knowledge gap in biodiversity distributions. There is still limited knowledge for freshwater fish species despite the importance of focusing conservation efforts towards this group due to their alarming extinction risk and the increasing human pressure on freshwater ecosystems. Here, we addressed the Wallacean shortfall for freshwater fish faunas across Europe by using the completeness indicator derived from species accumulation curves to quantify the fish sampling efforts. The multiple potential drivers of completeness that were previously related to the sampling efforts for other species (i.e., population density, nature reserves, or distance to cities) were tested using a 10 × 10 km2 grid resolution, as well as environmental (e.g., climatic) factors. Our results suggested that although there was an overall spatial pattern at the European level, the completeness was highly country-dependent. Accessibility parameters explained the sampling efforts, as for other taxa. Likewise, climate factors were related to survey completeness, possibly pointing to the river conditions required for fish sampling. The survey effort map we provide can be used to optimize future sampling, aiming at filling the data gaps in undersampled regions like the eastern European countries, as well as to account for the current bias in any ecological modeling using such data, with important implications for conservation and management.

Arctiini Leach, [1815] (Lepidoptera, Erebidae, Arctiinae) in a savanna areas of the Environmental Protection Area Alter do Chão, Santarém, Pará, Brazil

The richness and abundance of representatives of Arctiini (Lepidoptera: Erebidae: Arctiinae) was studied considering 88 representative points of savanna in the Alter do Chão Environmental Protection Area (APA), in the municipality of Santarém, state of Pará, Brazil. Moths were sampled monthly from December 2014 to December 2016 (except May 2015), with a light trap, Pennsylvania model, during a new moon night from 6:00 p.m. to 6:00 a.m. the following day. Abundance (N), richness (S) and diversity index (H’), Shannon uniformity (J’) index and Berger-Parker (BP) dominance were analyzed. Wealth estimators “Chao” (1st and 2nd order), “Jackknife” (1st and 2nd order) and “Bootstrap” were also used. A total of 1,375 specimens (N) belonging to 122 species (S) were captured. Idalusmulticolor (Rothschild, 1909) and Pheialateralis Klages, 1906 appear as new records for the Brazilian Amazon. The values for the analyzed parameters were H’= 3.25, J’= 0.67 and BP = 0.33. The estimators and “Bootstrap” (140) and “Jackknife 2nd order” (180) measured that between 14% and 33% of species can still be found, respectively, as shown by the species accumulation curve. The results of this study indicate changes in the faunal composition with an equivalent distribution of species between the Ctenuchina and Phaegopterina subtribes, quite different from anthropized and forested areas that present a predominance of Phaegopterina. In this way, the conservation of savanna fragments present in the APA Alter do Chão contributes to the maintenance of the local fauna and expands the knowledge of Arctiini in the Amazon.

High polychaete diversity in the Gulf of Guinea (West African continental margin): The influence of local and intermediate scale ecological factors on a background of regional patterns

The Tropical East Atlantic is one of the least studied areas in the world's oceans, and thus a blank spot on the map of marine studies. Shaped by dynamic currents and shifting water masses, it is a key region in discussions about marine ecology, biodiversity, and zoogeography, while facing numerous, poorly understood, and unmonitored threats associated with climate change, acidification, and pollution. Polychaete diversity was assessed along four transects along the Ghana coast, from shallow to deep bottoms and distributed along the whole upwelling marine ecoregion. Despite high sampling effort, steep species accumulation curves demonstrated the necessity of further sampling in the region. We observed zonation of fauna by depth, and a decrease in species richness from 25 m to 1000 m depth. Polychaete communities were influenced by sediment type, presence of oxygen minimum zones, and local disturbances caused by elevated barium concentrations. Similar evenness along the depth gradient reflected the importance of rare species in the community structure. Differences in phylogenetic diversity, as reflected by taxonomic distinctness, were small, which suggested high ecosystem stability. The highly variable species richness at small scale (meters) showed the importance of ecological factors giving rise to microhabitat diversity, although we also noticed intermediate scale (50–300 km) differences affecting community structure. About 44 % of the species were rare (i.e. recorded only in three or fewer samples), highlighting the level of patchiness, while one fifth was distributed on all transects, therefore along the whole upwelling ecoregion, demonstrating the influence of the regional species pool on local communities at particular stations. Our study yielded 253 species, increasing the number of polychaetes known from this region by at least 50 %. This casts doubt on previous findings regarding Atlantic bioregionalization, biodiversity estimates and endemism, which appear to have been more pronouncedly affected by sampling bias than previously thought.

Monitoring diversity and abundance of mammals with camera-traps: a case study of Manas National Park, Assam, India

Information on the status and distribution of species within a geographical area is vital for developing effective conservation plans. We conducted camera-trapping (n = 473) to determine diversity, species composition, relative abundance index, sampling effort, and conservation status of mammals in forested habitats of Manas National Park, Assam, India. Camera stations accumulated data over 11,388 trap nights over three sampling years: 2017–2019. Camera-traps recorded 34 mammalian species belonging to seven orders, 15 families, and 29 genera, with 22,738 independent records. Among them, 17 species are globally threatened or 50% of the recorded species. The species accumulation curve reached an asymptote, indicating an adequate sampling design for obtaining a robust inventory of the mammalian community. Despite a history of ethnopolitical conflict, almost all mammals expected to occur in the park were detected. Our study will enable future evaluations of the recovery process in terms of changes in mammal abundance over time.

Complementary Sampling Methods to Improve the Monitoring of Coastal Lagoons

Monitoring the ecological status of marine coastal lagoons requires the integration of multiple indices. However, the efficacy of monitoring programs is complicated by the diverse array of habitats that conform coastal lagoons. In this study, we compared four sampling methods (25-m and 50-m beach seines, beam trawl and Riley push net) in the Ria Formosa coastal lagoon (South Portugal) for assessing fish assemblage and diversity. We compared species richness and assemblage structure with species accumulation curves and multivariate analysis, and assessed diversity patterns using taxonomic, phylogenetic and functional diversity indices. Variation in fish assemblage structure was mostly explained by gear type, and almost all diversity metrics varied not only according to sampling method but also depending on habitat characteristics and season. Based on operational costs and diversity patterns captured by each gear, we conclude that the combined use of 25-m beach seine and beam trawl is the preferred approach. The proposed methodology will provide the data necessary for assessment of ecological status of coastal lagoons.

Estimating species richness and density of a bird community in a coastal lagoon on the Mexican Pacific

In this study we assess the bias in estimates of bird richness in a tropical wetland. We used 18 months of data from point counts to estimate the species richness in a coastal lagoon in Oaxaca and computed eight species richness estimators. We evaluated estimate inaccuracy using the sum of total richness that we obtained with combined sampling techniques between 2006 and 2010. We selected the richness estimator of minimum inaccuracy and used randomized species accumulation curves to investigate differences in species densities obtained with 10 and 20-minute counts. To ascertain if habitat type influenced richness estimates, we compared the bird diversity associated with contrasting mangrove and estuarine environments. The total richness for the lagoon was 185 species and the jackknife 2 richness estimator showed the minimum inaccuracy. The randomized accumulation curves of 10 and 20 minutes displayed partially overlapping confidence intervals and an increasing time lag between the count durations at equivalent densities. The rarefaction curves from contrasting habitat types showed significantly higher richness and species density in the estuary while the jackknife 2 estimator indicated similar sample coverage in both habitats. We identify important consequences of the sampling methodology that we used and conclude that point count sampling resulted in incomplete species detection but facilitated comparative analyses.

Benthic megafaunal biodiversity of the Charlie-Gibbs fracture zone: spatial variation, potential drivers, and conservation status

The Charlie-Gibbs Fracture Zone (CGFZ) is a prominent geological feature offsetting the Mid-Atlantic Ridge (MAR), consisting of two parallel fractures, creating a highly variable seafloor bathymetry. It has been defined as the most important latitudinal biodiversity transitional zone on the MAR. Despite this recognition, the faunal communities living on the fracture zone have not been extensively described. A remotely operated vehicle (ROV) was utilised during the TOSCA (Tectonic Ocean Spreading at the Charlie-Gibbs Fracture Zone) survey. The survey included five ROV video transects at depths between 560 and 2900 m. The objectives of the study were to use this video footage to quantify benthic megafaunal density and biodiversity patterns on the CGFZ and their environmental drivers. Species accumulation curves and generalised additive modelling show that depth and the presence of hard substrates play an important role in explaining species richness and abundance at the CGFZ. Coral taxa showed highest abundance between depths of 1500 and 2000 m, while sponge taxa were more abundant between 1750 and 2250 m. A dense sponge aggregation was identified on a ridge feature at 2250 m depth. The high biodiversity and presence of dense sponge aggregations and coral gardens found in this study highlight the need for detailed surveys to help support decisions made by governing bodies on the protection status of the CGFZ.

50 Years of Cumulative Open-Source Data Confirm Stable and Robust Biodiversity Distribution Patterns for Macrofungi.

Fungi are a hyper-diverse kingdom that contributes significantly to the regulation of the global carbon and nutrient cycle. However, our understanding of the distribution of fungal diversity is often hindered by a lack of data, especially on a large spatial scale. Open biodiversity data may provide a solution, but concerns about the potential spatial and temporal bias in species occurrence data arising from different observers and sampling protocols challenge their utility. The theory of species accumulation curves predicts that the cumulative number of species reaches an asymptote when the sampling effort is sufficiently large. Thus, we hypothesize that open biodiversity data could be used to reveal large-scale macrofungal diversity patterns if these datasets are accumulated long enough. Here, we tested our hypothesis with 50 years of macrofungal occurrence records in Norway and Sweden that were downloaded from the Global Biodiversity Information Facility (GBIF). We first grouped the data into five temporal subsamples with different cumulative sampling efforts (i.e., accumulation of data for 10, 20, 30, 40 and 50 years). We then predicted the macrofungal diversity and distribution at each subsample using the maximum entropy (MaxEnt) species distribution model. The results revealed that the cumulative number of macrofungal species stabilized into distinct distribution patterns with localized hotspots of predicted macrofungal diversity with sampling efforts greater than approximately 30 years. Our research demonstrates the utility and importance of the long-term accumulated open biodiversity data in studying macrofungal diversity and distribution at the national level.

Species accumulation in small–large vs large–small order: more species but not all species?

Although groups of small habitat patches often support more species than large patches of equal total area, their biodiversity value remains controversial. An important line of evidence in this debate compares species accumulation curves, where patches are ordered from small–large and large–small (aka ‘SLOSS analysis’). However, this method counts species equally and is unable to distinguish patch size dependence in species’ occupancies. Moreover, because of the species–area relationship, richness differences typically only contribute to accumulation in small–large order, maximizing the probability of adding species in this direction. Using a null model to control for this, I tested 202 published datasets from archipelagos, habitat islands and fragments for patch size dependence in species accumulation and compared conclusions regarding relative species accumulation with SLOSS analysis. Relative to null model expectations, species accumulation was on average 2.7% higher in large–small than small–large order. The effect was strongest in archipelagos (5%), intermediate for fragments (1.5%) and smallest for habitat islands (1.1%). There was no difference in effect size among taxonomic groups, but each shared this same trend. Results suggest most meta-communities include species that either prefer, or depend upon, larger habitat patches. Relative to SLOSS analysis, null models found lower frequency of greater small-patch importance for species representation (e.g., for fragments: 69 vs 16% respectively) and increased frequency for large patches (fragments: 3 vs 25%). I suggest SLOSS analysis provides unreliable inference on species accumulation and the outcome largely depends on island species–area relationships, not the relative diversity value of small vs large patches.

Diversity, Structural, and Regeneration Analysis of Woody Species in the Afromontane Dry Forest of Harego, Northeastern Ethiopia

The study was conducted in the Harego dry Afromontane forest, Northeastern Ethiopia, to analyze woody species composition, diversity, structure, and regeneration status. To collect the vegetation data, a total of 67 sample plots measuring 400 m 2 20 m × 20 m were laid systematically. Species identity, abundance, height, and diameter at breast height (DBH) were recorded for each sample plot. Diversity, structural, and regeneration status were analyzed for the forest. A total of 50 woody species representing 35 families and 44 genera were identified and recorded. According to the IUCN Red List Category, Rhus glutinosa A. Rich and Prunus africana (Hook.f.) Kalkm. are vulnerable species. Fabaceae was the dominant family, and of the total species, 27 were shrubs, 19 were trees, and 4 were climbers. The species accumulation curve indicates that the majority of plant species in the study area were captured by our sampling efforts. The values of true Shannon (N1 = 17) and true Simpson (N2 = 11) indicate that species in the Harego forest are more or less evenly distributed. The abundance-frequency ratio of all woody species (WI = >0.05) indicates the heterogeneity of species composition. The total density and basal area were 4400 stems ha−1 and 9.66 m2 ha−1, respectively. The majority of the species fallen into the lower IVI classes. The diameter and height class distribution revealed an inverted J-shape. The increase in population demand and disturbance shows a high variation in stand structure and hampered natural regeneration, which needs immediate conservation actions.

Taxonomic uncertainty and the challenge of estimating global species richness

Taxonomic uncertainty and the challenge of estimating global species richness