Brazilian Biome Research Articles

Essential oil from leaves of Myrciaria floribunda (H. West ex Willd.) O. Berg has antinociceptive and anti-inflammatory potential.

Myrciaria floribunda is a plant that is distributed across different Brazilian biomes such as the Amazon, Caatinga, Cerrado, and Atlantic Forest, and it possesses antioxidant, antimicrobial, and anticancer properties. The antinociceptive and anti-inflammatory properties of the essential oil from M. floribunda leaves (MfEO) were examined in this study using mouse models. Gas chromatography-mass spectrometry was employed to describe the oil, and the results revealed that δ-cadinene, bicyclogermacrene, α-cadinol, and epi-α-muurolol predominated in the chemical profile. The oil stimulated a decrease in nociception in the chemical and thermal models used to evaluate acute antinociceptive activity. Findings from the use of pain pathway blockers to study the presumed underlying mechanism indicated opioid pathway activity. The anti-edematogenic effect, decreased cell migration, and generation of pro-inflammatory cytokines provided evidence of the anti-inflammatory potential of the essential oil from M. floribunda. According to this research, the essential oil from M. floribunda can effectively alleviate acute pain and inflammation.

The Brazilian Atlantic Forest genetic resources in patents and the challenges to control the economic use of biodiversity

The Atlantic Forest is the Brazilian biome with the greatest variety of plant species. Despite the potential of resources that can be used in the development of products and technologies, several species are imminently threatened with extinction. This study analyzes the technologies developed with native species of the Atlantic Forest, and their holders, using patent analysis. It also investigates methodological restrictions and gaps in information sources to relate the use of genetic resources to patented technologies, and also relates the use of these resources to the production and commercialization of products. We found that 92% of patents with native flora of the Atlantic Forest were developed and filled outside Brazil. The patents are mainly in the areas of agriculture livestock, medical or cosmetic preparations, food and beverages, and water, sewage, or waste treatment. The procedures for examining applications for patents, and control procedures for accessing biodiversity have limitations in identifying and monitoring the origin of genetic resources. The lack of transparent access to biodiversity results in the patent analysis as one of the main strategies used to evaluate the misappropriation of traditional knowledge associated with genetic resources, since patents have descriptive details of inventions and worldwide publicity.

Vegetações amazônicas e terras indígenas ameaçadas pelas próximas mudanças climáticas: Previsão de impacto nos biomas brasileiros

AbstractChanges in vegetation cover due to increasing frequencies of extreme climate events and anthropogenic pressure are already underway; so, predicting the impacts of the near‐future climate will be essential for developing mitigation strategies. We modelled the responses of Brazilian biomes to a future scenario (2070) of steady increases in atmospheric CO levels, adding soil data to better represent the multidimensional space of the environmental suitability of each biome. We also assessed the effects of changes in environmental suitability on the Brazilian network of protected areas and projected those effects on 1 km resolution maps. The area predicted to be affected by future climate change in Brazil and the consequent loss of suitable habitat surface is 2.59 Mkm2 – larger than the combined areas of Central America and Mexico – leading the current vegetation to a progressive replacement. We project major changes in the vegetation of the Amazon basin, with the replacement of rainforest by dryer vegetation in the southern and eastern regions of that basin, and the opening of a dry corridor in Pará State. We also project an expansion of 41% of the current caatinga cover in the Brazilian semiarid region, with large losses of suitable habitat surface of the current deciduous forest. Approximately, 37% of the coverage of protected areas in Brazil will be affected – with greater damage to indigenous lands. The speed of current environmental change is now unprecedented for the post‐glacial era, and will almost certainly lead to increased rates of extinction and the collapse of transition ecosystems. We propose the urgent creation of protected areas in regions designed without significant impacts, but contiguous to those that will be more seriously affected by climate change. Those areas will act as refugia preserving biodiversity, ecosystem services, and the cultural heritages of traditional populations.

Using land inequality to inform restoration strategies for the Brazilian dry forest

Forest and landscape restoration aims not only to restore ecosystems but to improve people's livelihoods. However, mapping of restoration often neglects key socioeconomic aspects such as land-access inequalities. In this article, we quantify and describe the distribution of vegetation deficits (areas that demand mandatory restoration) across small and large rural properties across 1,204 municipalities of the Brazilian Caatinga biome. We mapped 313,537 ha of vegetation deficit, i.e. areas previously cleared that will need to be restored for legal compliance. This vegetation deficit is almost equally shared between 141,144 smallholders and only 2,986 in large properties. Around half of this vegetation deficit is spatially clumped mainly in the East and along the main river basin of the region dominated by rich large-holders. On the other hand, spatially scattered and poor small landowners hold around another half of the vegetation deficit across several municipalities. Because of such an unequal distribution of native vegetation deficit, we propose three different restoration strategies to account for land-access inequalities and socioeconomic differences at the municipality level. This is one of the first studies to clearly address land inequality and socioeconomic profile of landowners to inform adapted restoration strategies. Restoration planning that ignores land concentration and socioeconomic contexts may reproduce inequalities known to be one of the main causes of ecosystem degradation across Global South countries.

The Role of Private Reserves of Natural Heritage (RPPN) on natural vegetation dynamics in Brazilian biomes

Despite having the richest biodiversity in the world, Brazil has lost vegetation cover in all biomes, with the agribusiness being an important driver of such changes. Different governance systems, decentralized actions and public policies have been developed to control deforestation, and in this study, we focus on the role of Private Reserves of Natural Heritage (RPPN) as an instrument for the conservation and recovery of natural vegetation. Therefore, we raise the following questions: How many RPPNs are there and what are their spatial distribution? Are RPPNs an important mean of conservation/restoration of Brazilian biomes? Do they contribute (at statistically significant levels) to the conservation of natural vegetation within their respective rural properties compared with rural properties without private reserves? Thus, we investigated the natural vegetation cover (between 1990 and 2018) in rural properties with and without RPPNs looking at the municipalities where RPPNs are found, and analyzing the results at country and biome levels. The results indicate that RPPNs are significantly associated with gains in natural vegetation cover in the Cerrado, Caatinga and Atlantic Forest biomes. We conclude that RPPNs have great potential in recovering natural landscapes associated to the Brazilian biomes. However, their few numbers across the Brazilian territory (1750 units of RPPN) and spatially highly concentrated in the Cerrado and Atlantic Forest, challenges the capacity of this conservation strategy to deal with the environmental degradation promoted by the expansion of economics activities across the country.

Morphometric Analysis of a Trapdoor Spider (Araneae, Idiopidae) across Different Brazilian Biomes Reveals the Geographic Variation of Spiders from the Caatinga Biome

Widespread species are exposed to different environmental drivers and can consequently present variations in body shape and/or size. Trapdoor spiders of the genus Idiops are generally associated with a sedentary lifestyle and limited dispersion. However, the species Idiops pirassununguensis has a wide distribution, occurring in a diverse range of distinct environmental conditions, with their presence recorded in the Amazon, Caatinga, and Cerrado Brazilian biomes. We investigated how their morphological variation is structured regarding the biomes in which they occur through a morphometric analysis of the linear measurements and morphogeometric shapes of 64 specimens. Combining different methods proved to be a valuable approach to understanding how the spider’s morphology varies in different environments. The results were congruent and complementary, indicating intraspecific geographic variation, with the Caatinga specimens being distinct from their biome conspecifics. In Caatinga, a biome with periods of severe drought and warm climate, I. pirassununguensis specimens were found to be smaller, in addition to having narrower and elongated sternums and shorter legs. The morphological structuring herein is consistent with the results found comparing animals from Caatinga and other Brazilian biomes. Despite differences in their non-sexual structures, the specimens share a set of diagnostic sexual characteristics for the species, allowing all individuals to be classified as belonging to the same species.

Black fly species and their association with Brazilian biomes

The family Simuliidae occurs widely around the globe, except in the Antarctic region, deserts, and islands that lack water streams. Because fresh stream water environments are breeding grounds for their immature forms. This study sought to relate and compare Brazilian biomes based on their simuliid faunas. After gathering information on the distribution patterns of Simuliid species included in the most recent global taxonomic review, a table on their presence in the Brazilian territory was prepared, indicating the regions in which the different species were present in each biome. Subsequently, correspondence and cluster analyses were performed to determine the biomes with which the species were most associated and the similarities of the simuliid faunas among those biomes, respectively. The correspondence analysis showed that most species were predominantly associated with three biomes: The Amazon, Cerrado, and Atlantic Forest, while the cluster analysis showed that the simuliid faunas of the Cerrado and Atlantic Forest are similar and that when taken together, these two biomes are similar to the Amazon biome.

Streamflow prediction based on machine learning models and rainfall estimated by remote sensing in the Brazilian Savanna and Amazon biomes transition

Streamflow prediction based on machine learning models and rainfall estimated by remote sensing in the Brazilian Savanna and Amazon biomes transition

Shotgun Metagenomic Sequencing Reveals Virome Composition of Mosquitoes from a Transition Ecosystem of North-Northeast Brazil.

A wide diversity of pathogenic mosquito-borne viruses circulate in the Brazilian Amazon, and the intense deforestation can contribute to the spread of these viruses. In this context, this study aimed to investigate the viral diversity in mosquitoes of the genera Aedes, Culex, Haemagogus, and Sabethes from a transition area between the Amazon, Cerrado, and Caatinga biomes in Brazil. Metagenomic high-throughput sequencing was used to characterize the virome of 20 mosquito pools. A total of 15 virus-like genomes were identified, comprising species genomically close to insect-specific viruses of the families Iflaviridae, Metaviridae, Lispiviridae, Rhabdoviridae, Xinmoviridae, and Parvoviridae and species of plant viruses of the families Solemoviridae, Virgaviridae, and Partitiviridae. However, sequences of viruses associated with human and animal diseases were not detected. Most of the recovered genomes were divergent from those previously described. These findings reveal that there are a large number of unknown viruses to be explored in the middle-north of Brazil.

Remote sensing environmental indicators for monitoring spatial and temporal dynamics of weather and vegetation conditions: applications for Brazilian biomes.

The SAFER (Simple Algorithm for Evapotranspiration Retrieving) algorithm and the radiation use efficiency (RUE) model were coupled to test large-scale remote sensing environmental indicators in Brazilian biomes. MODIS MOD13Q1 reflectance product and gridded weather data for the year 2016 were used to demonstrate the suitability of the algorithm to monitor the dynamics of environmental remote sensing indicators along a year in the Brazilian biomes, Amazon, Caatinga, Cerrado, Pantanal, Atlantic Forest, and Pampa. Significant spatial and temporal variations in precipitation (P), actual evapotranspiration (ET), and biomass production (BIO) yielded differences on water balance (WB = P-ET) and water productivity (WP = ET/BIO). The highest WB and WP differences were detected in the wettest biomes, Amazon, Atlantic Forest, and Pampa, when compared with the driest biome, Caatinga. Rainfall distribution along the year affected the magnitude of the evaporative fraction (ETf), i.e., the ET to reference evapotranspiration (ET0) ratio. However, there was a gap between ETf and WB, which may be related to the time needed for recovering good soil moisture conditions after rainfalls. For some biomes, BIO related most to the levels of absorbed photosynthetically active radiation (Amazon and Atlantic Forest), while for others, BIO followed most the soil moisture levels, depicted by ETf (Caatinga, Cerrado, Pantanal, and Pampa). The large-scale modeling showed suitability for monitoring the water and vegetation conditions, making way to detect anomalies for specific periods along the year by using historical images and weather data, with strong potential to support public policies for management and conservation of natural resources and with possibilities for replication of the methods in other countries.

Circumscription of Abarema (Leguminosae, Caesalpinioideae, Mimosoid clade)

The genus Abarema (Caesalpinioideae, Mimosoid clade), as traditionally circumscribed, emerged as polyphyletic in recent phylogenetic studies. The type species of the genus, Abarema cochliacarpos, is positioned within the Inga clade, separate from the remaining species previously included in the genus (now combined to Punjuba and Jupunba genera). Here we present the new circumscription of Abarema. The two species included in the genus occur in the Atlantic Forest and Caatinga biomes in Brazil. We provide a morphological description of Abarema and its two species, an identification key, conservation status and a geographic distribution map.

Capixaba ant species inventory is far from complete: A local scale assessment of the ants (Formicidae) reveals the importance of diversity studies and entomological collections

The Atlantic Forest is the third largest biome in Brazil, the most sampled, and has the second highest diversity of ant species described. However, these data are spatially very heterogeneous, with the central region of the Atlantic Forest being better sampled. There is a visible gap from the south of Bahia to the north of Rio de Janeiro, comprising the entire state of Espírito Santo. Knowing this biodiversity gap, in this work, we list the ant fauna (Hymenoptera, Formicidae) deposited in the Coleção Entomológica of the Reserva Natural Vale (CERNV), located in the municipality of Linhares, Espírito Santo. The CERNV has 143 ants collected from August 1984, belonging to 63 species, 29 genera, and eight subfamilies. Of the 143 records, 94 are ant workers (66%), 27 queens (19%), and 22 males (15%). Seventy three percent of the ant workers are identified, 52% of queens and 36% of males. The species with the most individuals deposited are Camponotus sp. (15 records), Eciton burchellii (8), Atta sexdens (7), Neoponera villosa (7), and Solenopsis sp. (6). Among the identified ants, 12 species were recorded for the first time in the state of Espírito Santo, Brazil. The collection still holds workers (and probably unidentified males) of a species considered endangered, Dinoponera lucida. We can observe the importance of biological collections for the knowledge of biodiversity, local and regional since species are recorded for the first time in a state whose biome is widely studied, helping to fill in Linnean and Wallacean shortfalls.

Toward a forest transition across the Brazilian Atlantic Forest biome

The world has entered the United Nations Decade on Ecosystem Restoration (2021–2030), yet many regions of the world still face environmental degradation. In this context a question arises: under what conditions may a given region shift from a trajectory of environmental degradation to environmental recovery? Answering this question constitutes an important endeavor for the scientific community, policymakers, and organizations leading the planning and implementation of restoration projects. This study examines some of the human-environment conditions underpinning the net gains in natural forest cover in a region that has experienced environmental degradation: the Atlantic Forest biome, Brazil. Using land-use/cover (LULC) data, we assessed the loss and successive gain in forest cover during the 1987–2001 and 2001–2015 periods. Municipality-level statistics on agriculture and economy, together with LULC and biophysical data, were used to develop models for assessing forest cover trajectories. Of the 1,972 municipalities experiencing net forest loss during the 1987–2001 period, 59% shifted their trajectory to a net gain during the 2001–2015 period. This shift, known as forest transition, followed a complex socio-economic pathway characterized by (i) the stagnation of traditional agricultural activities favoring the replacement of pasturelands by mechanized agriculture, and (ii) the emergence of non-agricultural rural activities together with multifunctional landscapes. Furthermore, a trend of decrease in precipitation seems to be associated with land abandonment, thus, favoring the return of natural vegetation. Our findings suggest that forest transition at the biome level is possible if environmental and land regulations take advantage of specific context-dependent situations that foster net forest gains.

Soil carbon and nitrogen stocks following forest conversion to long-term pasture in Amazon rainforest-Cerrado transition environment

The conversion of Amazon rainforest to grasslands has significant implications for regional and global carbon cycling. The description of affected organic pools and their extent is crucial for accurate prediction of forest-to-pasture conversions. We assessed soil C and N stocks in granulometric fractions of soil organic matter (SOM), particulate organic matter (POM) and mineral-associated organic matter (MAOM), following forest-to-pasture conversion in transition environments of the Brazilian Amazon rainforest and Cerrado biomes. Five study situations (SS) were selected in the Lontra River basin, Tocantins state, Brazil. The situations were established by the association between vegetation and soil classes: OFAr (Ombrophilous Forest on Orthodystric Arenosol); OFPt (Ombrophilous Forest on Petric Plinthosol); DCFr (Dense Cerrado on Acric Petroplinthic Ferralsol); DCAc (Dense Cerrado on Haplic Acrisol); and CSAr (Cerrado Sensu Stricto on Orthodystric Arenosol). In each SS, soil samples were collected in pasture areas with different planting times (between 10 and 30 years), in addition to a reference area with natural vegetation. DCFrP30 (30-y-old pasture) and DCFrNV (natural vegetation area) were statistically similar, both having the highest mean C stocks (0–20 cm: 41.5 ± 6.6 t C/ha; 0–40 cm: 64.6 ± 12.3 t C/ha; 0–60 cm: 85.0 ± 14.8 t C/ha; 0–100 cm: 102 ± 21.8 t C/ha) and N stocks (0–20 cm: 3.5 ± 0.6 t C/ha; 0–40 cm: 5.3 ± 0.9 t C/ha; 0–60 cm: 6.9 ± 1.1 t C/ha; 0–100 cm: 8.1 ± 1.5 t C/ha), especially in MAOM. The highest C-C3 (δ13C ≈ −27‰) losses occurred in newer pastures of OFAr and CSAr and in DCFr, while C-C4 (δ13C ≈ −14‰) gains were greater in POM and in 20-y-old pastures of OFPt and DCFr. Our results demonstrate significant change in stocks and distribution of soil C and N in SOM granulometric fractions following the conversion of forest to pasture. Moreover, the results give important insight into the development of strategies focused on the recovery and conservation of environmental quality and mitigation of climate change, particularly for the Amazon region where Cerrado-Amazon rainforest transition areas have been incorporated into agricultural land in recent years.

Phytochemical study of Magonia pubescens A. St.-Hil. and cytotoxicity of branches aqueous extract on breast cancer and leukemia cells

Magonia pubescens is a natural species from the Brazilian cerrado biome. Its fruits and seeds are used in the treatment of seborrheic dermatitis, a common inflammatory skin disease. In this work, the known compounds lapachol, stigmasterol, maniladiol and scopoletin were isolated from hexane and dichloromethane extracts of M. pubescens branches. The aqueous extract of this material was fractioned through a liquid-liquid partition and the obtained fractions were analyzed by UHPLC-MS/MS. The results obtained were compared with data from three databases, leading to the putative identification of 51 compounds from different classes, including flavonoids, saponins and triterpenes. The cytotoxicity of aqueous fractions was assayed against breast cancer (MDA-MB-231) and leukemia (THP-1 and K562) cells. The best activity was observed for fraction AE3 against MDA-MB-231 cells (IC50 30.72 µg.mL−1).

Soil enzymatic activity in Brazilian biomes under native vegetation and contrasting cropping and management

Enzymatic activity is a useful indicator for the evaluation of soil biological components. However, a detailed analysis of such indicators in Brazilian soils is lacking. In this study, the activity of soil enzymes was evaluated using data from 73 publications covering 57 locations across all six biomes and eight soil orders out of the 13 that occur in Brazil. The results indicated a wide variation of enzymatic activity in soils, where the means in μg p-nitrophenol g−1 soil h−1 were 569, 116, 112, and 80 for acid phosphatase, alkaline phosphatase, β-glucosidase, and arylsulfatase, respectively. Likewise, values of 148 μg reducing sugars g−1 soil day−1 for cellulase, 57 μg triphenyl tetrazolium formazan g−1 soil day−1 for dehydrogenase, and 38 μg N-NH4+ g−1 soil h−1 for urease were recorded. Soil organic matter and microbial biomass were the best attributes correlated with enzymatic activity, followed by clay content and pH. A more detailed analysis of the acid phosphatase, arylsulfatase, and β-glucosidase activities showed that land-use effects were more pronounced in the Atlantic Forest and Cerrado than in the Caatinga biome. Soils under non-tillage and integrated crop-livestock systems showed higher enzymatic activity than soils under conventional tillage. Soils housing higher biodiversity and delivering higher crop yields also presented higher enzymatic activity, especially in terms of arylsulfatase and β-glucosidase. Enzymatic activity has been shown to be a versatile indicator of soil quality, as it can elucidate how to achieve high-quality standards in tropical and subtropical soils.

Cytotoxic screening of plants from the Brazilian Atlantic Forest has led to the identification of Casearia arborea and Sorocea hilarii as sources of antitumor compounds

In the present study, we have evaluated the cytotoxic activity of 282 extracts from 72 native plant species of the Brazilian Atlantic Forest biome. As a result, Casearia arborea and Sorocea hilarii leaves extracts showed cytotoxic activity against three tumour cell lines tested (B16F10, SW480 and Jurkat). After bioassay-guided fractionation, the bioactive fractions were submitted to the dereplication study via High-performance Liquid Chromatography, connected to High-resolution Mass Spectrometry (HPLC-ESI-QTOF/MS) analysis, combined with a Global Natural Products Social Molecular Networking (GNPS) tool. A combination of bioactivity-guided and dereplication approaches resulted in the putative annotation of 27 clerodane diterpenes and 9 flavonoids as main compounds present in the cytotoxic fractions of C. arborea. Regarding the active fraction of S. hilarii, 10 megastigmans, 17 spirostane steroids derivatives and 2 lignans were putatively identified. In conclusion, Casearia arborea and Sorocea hilarii are potential sources of antitumor compounds.

Determination of the critical threshold for the occurrence of fires in the Parque Nacional de Brasília (Brazil) through temporal analysis using spectral índices

The Brazilian Savannah is one of the largest biomes in Brazil. Unfortunately, human pressure is aggravating the degradation processes of the biome and, together with the drought processes, fire events are a major concern. Monitoring tools must be designed, especially those involving the concepts of remote sensing, in anticipation of the fire phenomenon, mitigating the devastating effects. Therefore, the present research aims to determine the critical threshold for the occurrence of fires through the diagnosis of the conditions of greenness, humidity and senescence of the vegetation using the temporal analysis of Sentinel-2 images in the Parque Nacional de Brasília. Therefore, it is necessary to quantitatively determine each condition through the analysis of past events, determining the criticality threshold that conditions the region to present conditions that favor the onset of a fire, as well as the construction of an algorithm, in the Google Earth Engine. The study area is the Parque Nacional de Brasília, with the image data collection Harmonized Sentinel-2 MSI: MultiSpectral Instrument, Level-1C inside the Google Earth Engine. The algorithm aims to build a masking system to remove materials from the scenes, as well as the calculation of the NDVI, NDII, PSRI and dNBR indices, extracting the data through the mask of burned pixels. It was possible to identify six periods of fire occurrence, the data extraction allowed the statistical determination of the threshold, which was 0,580 for the NDVI, 0,015 for the NDII and 0,150 for the PSRI.

Pseudobombax parvifolium Hydroalcoholic Bark Extract: Chemical Characterisation and Cytotoxic, Mutagenic, and Preclinical Aspects Associated with a Protective Effect on Oxidative Stress.

Plants have long been used in traditional medicine to treat illnesses. Nevertheless, their chemical diversity requires studies to establish the extract dosage and its safe use. Pseudobombax parvifolium, an endemic species of the Brazilian Caatinga biome, is commonly used in folk medicine, due to its anti-inflammatory properties related to cellular oxidative stress; however, its biological properties have scarcely been studied. In this study, we chemically characterized the P. parvifolium hydroalcoholic bark extract (EBHE) and evaluated its cytotoxic, mutagenic, and preclinical aspects, as well as its antioxidant effect. Our phytochemical analysis revealed a significative total polyphenol content and identified loliolide for the first time in this species. Cytotoxicity, mutagenicity, and acute oral and repeated dose indicated no toxic effects on cell culture, Drosophila melanogaster, and Wistar rat exposure to different EBHE concentrations, respectively. Furthermore, we observed a significant decrease in lipid peroxidation and a mild hypoglycemic and hypolipidemic effect with repeated oral dosing of EBHE. Although there were no significant changes in glutathione content, we did observe a significant increase in superoxide dismutase at a dose of 400 mg/kg and in glutathione peroxidase at doses of 100, 200, and 400 mg/kg. These findings suggest that EBHE has potential as a source of bioactive molecules, and it can be used safely in traditional medicine and in the development of herbal medicines for application in the public health system.

Tree community structure in a reserve area at the Federal Goiano Institute – Rio Verde Campus

The Cerrado Biome is the second largest biome in Brazil, it has a rich diversity of fauna and flora, it no longer has its original coverage, even the protected reserves suffer from anthropic actions and invasive plants and animals. In addition, the cerrado has a diversity of habitats and numerous plant species that are at risk of extinction. Therefore, tools such as a floristic survey and a phytosociological study are used to study degraded areas that suffer from anthropic action and modified fragments. Thus, this work aimed to evaluate the floristic composition and structure of the shrub-tree community in a reserve area located at Instituto Federal Goiano. Fifteen systematized plots of 20x20m were established, spaced 10m apart and distributed in four transects, totaling 0.6 ha of sampling. All tree individuals with CAP ≥ 10 cm were numbered using aluminum plates. Circumference measurements were obtained using a tape measure and height was estimated. Classic phytosociological parameters were calculated. A total of 618 individuals distributed in 21 families and 41 species were sampled. Six individuals were not identified. The Shannon diversity index was 2.56 and the Pielou evenness was 0.69. It is concluded that the diversity of species found within the plots is much lower than it should be, with low species variability and the distribution of individuals is disproportionate.