Higher Plant Species Research Articles

Local representation of change and conservation of a Brazilian Caatinga refuge

A caatinga brasileira é uma das florestas tropicais secas mais ameaçadas do mundo, principalmente devido á fragmentação de habitats em função das pressões antrópicas. No entanto, as regiões montanhosas da Caatinga são consideradas refúgios de biodiversidade, com elevada riqueza de espécies vegetais, as quais são utilizadas para diversas finalidades por populações humanas locais. O presente estudo buscou identificar o conhecimento ecológico local das comunidades rurais no entorno de uma Serra na região semi-árida do Brasil, considerada um refúgio para a biodiversidade. O estudo foi realizado por meio de entrevistas semiestruturadas, com informantes-chave sendo selecionados pela técnica de amostragem de bola de neve. Segundo os informantes, a serra representa o resgate na memória de paisagens anteriores, ligadas à biodiversidade que ela contém e explicando a importância como fonte de recursos e influência nos regimes locais de chuvas. Para as populações locais, a conservação da biodiversidade da Caatinga representa mais do que apenas a preservação da fauna e flora, compreendendo também a permanência das funções dos ecossistemas para a manutenção de suas atividades.

The molecular mass and isoelectric point of plant proteomes

BackgroundCell contain diverse array of proteins with different molecular weight and isoelectric point (pI). The molecular weight and pI of protein play important role in determining the molecular biochemical function. Therefore, it was important to understand the detail regarding the molecular weight and pI of the plant proteins.ResultsA proteome-wide analysis of plant proteomes from 145 species revealed a pI range of 1.99 (epsin) to 13.96 (hypothetical protein). The spectrum of molecular mass of the plant proteins varied from 0.54 to 2236.8 kDa. A putative Type-I polyketide synthase (22244 amino acids) in Volvox carteri was found to be the largest protein in the plant kingdom. However, Type-I polyketide synthase was not found in higher plant species. Titin (806.46 kDa) and misin/midasin (730.02 kDa) were the largest proteins identified in higher plant species. The pI and molecular weight of the plant proteins showed a trimodal distribution. An acidic pI (56.44% of proteins) was found to be predominant over a basic pI (43.34% of proteins) and the abundance of acidic pI proteins was higher in unicellular algae species relative to multicellular higher plants. In contrast, the seaweed, Porphyra umbilicalis, possesses a higher proportion of basic pI proteins (70.09%). Plant proteomes were also found to contain selenocysteine (Sec), amino acid that was found only in lower eukaryotic aquatic plant lineage. Amino acid composition analysis showed Leu was high and Trp was low abundant amino acids in the plant proteome. Additionally, the plant proteomes also possess ambiguous amino acids Xaa (unknown), Asx (asparagine or aspartic acid), Glx (glutamine or glutamic acid), and Xle (leucine or isoleucine) as well.ConclusionThe diverse molecular weight and isoelectric point range of plant proteome will be helpful to understand their biochemical and functional aspects. The presence of selenocysteine proteins in lower eukaryotic organism is of interest and their expression in higher plant system can help us to understand their functional role.

First fossil record of an East Asian endemic genus Sladenia (Sladeniaceae) from its modern range: Implications for floristic evolution and conservation biology

AbstractFossil records of endemic plants play an important role in recognizing the floristic history of East Asia and thereby facilitate the conservation of plant diversity in the region. However, the fossil record of many extant East Asian endemic genera remains poorly documented thus far. Here, we report an infructescence fossil of an East Asian endemic genus, Sladenia (Sladeniaceae), from the early Miocene of southeastern Yunnan, China. The fossil is characterized by: (i) dichasial cymes; and (ii) flask‐shaped ovary with dense subparallel ribs on the surface extending from the base to the distal end of the united style. It represents the first fossil record of Sladenia in Asia, showing that the genus was established in the region at least by the early Miocene. Given that a much older fossil record of Sladeniaceae has been reported from Africa and the sister group of Sladenia is distributed only in Africa, Sladenia is not likely of East Asian origin. The present endemic status of Sladenia was possibly achieved by regional extirpation in Africa and taking refuge in East Asia. This case thus supports the “Museum” rather than “Cradle” hypothesis for the genesis of high plant species in the flora of East Asia. A comparison of the present fossil with extant Sladenia infructescence shows morphological stasis from the early Miocene to present. Such evolutionary tardiness might have resulted in the reduced fitness of the genus, which further caused its current endangered situation.

An ethnobotanical survey of useful wild plants in the north-eastern part of Croatia (Pannonian region)

Croatia, having high plant species diversity, offers an important opportunity for studying the wild plant uses in an ethnobotanical context. Comprehensive investigations were undertaken in Croatian Mediterranean areas, but little is currently known about wild plants traditionally used by local populations in the north-eastern part of Croatia situated in the Pannonian sector of Pannonio-Carpathian province. An ethnobotanical survey was undertaken at the two study areas: in the six settlements around the town of Našice and seven settlements in the area of Đakovo. A study was performed using questionnaires with 54 informants. A total of 44 plant taxa belonging to 25 families were recorded. The highest number of taxa belongs to families Asteraceae, Lamiaceae and Rosaceae. Plants were mostly used for the treatment of various disorders, while only seven taxa were used as food. Urtica dioica, Rosa canina and Matricaria chamomilla were the most important plants used for the treatment of various diseases. Comparison with traditionally used plants in neighbouring regions indicated similarity concerning plants uses and the mode of applications. The study represents a baseline for further investigations of valuable wild plants and ethnobotanical knowledge in the investigated area.

Comparative physiology and transcriptome analysis allows for identification of lncRNAs imparting tolerance to drought stress in autotetraploid cassava

BackgroundPolyploidization, pervasive among higher plant species, enhances adaptation to water deficit, but the physiological and molecular advantages need to be investigated widely. Long non-coding RNAs (lncRNAs) are involved in drought tolerance in various crops.ResultsHerein, we demonstrate that tetraploidy potentiates tolerance to drought stress in cassava (Manihot esculenta Crantz). Autotetraploidy reduces transpiration by lesser extent increasing of stomatal density, smaller stomatal aperture size, or greater stomatal closure, and reducing accumulation of H2O2 under drought stress. Transcriptome analysis of autotetraploid samples revealed down-regulation of genes involved in photosynthesis under drought stress, and less down-regulation of subtilisin-like proteases involved in increasing stomatal density. UDP-glucosyltransferases were increased more or reduced less in dehydrated leaves of autotetraploids compared with controls. Strand-specific RNA-seq data (validated by quantitative real time PCR) identified 2372 lncRNAs, and 86 autotetraploid-specific lncRNAs were differentially expressed in stressed leaves. The co-expressed network analysis indicated that LNC_001148 and LNC_000160 in autotetraploid dehydrated leaves regulated six genes encoding subtilisin-like protease above mentioned, thereby result in increasing the stomatal density to a lesser extent in autotetraploid cassava. Trans-regulatory network analysis suggested that autotetraploid-specific differentially expressed lncRNAs were associated with galactose metabolism, pentose phosphate pathway and brassinosteroid biosynthesis, etc.ConclusionTetraploidy potentiates tolerance to drought stress in cassava, and LNC_001148 and LNC_000160 mediate drought tolerance by regulating stomatal density in autotetraploid cassava.

Identification and quantitative analyses of medicinal plants in Shahgram valley, district swat, Pakistan

The traditional use of medicinal plants used by the inhabitants of Shahgram Valley, District Swat, Northern Pakistan. A total of 90 plant species from 53 families were studied through questionnaire, interviews and group discussions. However, the family Asteraceae (10%) was the most important and dominant family. Plant habit wise percentage was observed as (herb 65.55%), (shrubs 20%) and (trees 14.44%) and part used as whole plant (42.22%) fruit (15.55%), leaves (7.77%), bark (7.77%), seed (6.66%), root (6.66%), stem (3.33%), flower (3.33%), rhizome (2.22%), tuber (1.11%), shoot (1.11%), corms (1.11%) and bulb (1.11%). For the preparation of ethnomedicines, the locals use decoction (43.33%), crushed (40%), extract (11.11%), paste (4.44%) and original (1.11%). Out of 18 disease categories diuretic (16.05%) was observed as high. Route of ethnomedicines was observed high oral as (88.88%). The dose was observed as once a day (41.11%), twice (53.33%), (5.55%) thrice. Informant consensus factor (ICF) was observed high for a diuretic (0.94). Highest plant species use citation was observed for a diuretic (187) and lowest (3) for Stimulant. High FL value (100) was observed for A. bracteosa, while lowest (50.0) for M. cummunis. Among trees, M. azedarach got a first rank (22) followed by shrubs, B. lyceum (16) and herbs, A. plantago (13). The research was carried out to identify and document traditional uses of medicinal plants in the locality for new drug discovery. Medicinal flora was found towards extinction due to overgrazing and unwise utilization.

Overwintering Anuran Niche Preferences in a Series of Interconnected Ponds in Northwestern Florida

This study identified variations in pond bank gradients and associated plant assemblages to better understand niche preferences of 3 species of overwintering anurans—Acris gryllus (Southern Cricket Frog), Lithobates grylio (Pig Frog), and Lithobates sphenocephalus (Southern Leopard Frog)—in northwest Florida (Escambia County). We selected 7 regions of 4 interconnected ponds in a coastal pine flatwoods wetland. We conducted visual and auditory surveys once every week for 10 weeks from 17 January to 24 March 2017. We categorized survey areas along pond shorelines by the plant assemblage composition and species richness, pond bank steepness, and sunlight exposure. We looked for correlations between each species and specific niche characteristics. None of the anuran species studied showed a preference for the amount of sunlight or the slope of the pond bank. However, plant species richness was positively correlated with Southern Cricket Frogs and negatively correlated with Pig Frogs; thus, there was a very strong negative correlation between Pig Frogs and Southern Cricket Frogs. Southern Cricket Frogs, the smallest frog species in this study, prefers high plant species richness, possibly for increased cover from predators, and avoids potential predators like Pig Frogs. Pig Frogs prefer lower species richness, relying on open water for escape. The Southern Leopard Frog showed no vegetation preferences, possibly because the species is more adaptable and has a variety of predator evasion methods. Wetland plant assemblages are an accurate reflection of life-history habits of anurans, particularly predator evasion tactics.

The Role of MicroRNAs in Defense against Viral Phytopathogens

: MicroRNAs have been considered as an endogenous post-transcriptional gene silencing mechanism for transcription regulation. Additionally, reports are indicative of their involvement in plant viral defence. It seems that horizontal miRNA transfer from pathogenic viral and viroid genomes into plants has evolved into counter-defence mechanism(s) against their invasions. miRNAs of a green alga and 16 other higher plant species, with/without endogenous function, were searched for their energetically favorable target sites in the complete genomes of plant-specific invading viruses and viroids. Interestingly, 6524 and 250 potent target sites were found in 759 viral and 16 viroid genomes, respectively. Also, in 5589 viral encoding genes/sequences, 7583 potent target sites from 638 plant invasing viruses were found to be targeted by 1019 miRNAs (belonging to 636 miRNA families). Some miRNA families including miR171, miR156 and miR159 had wide target range in viral genomes; demonstrating possible plant-virus coevolution and at the same time a degree of conservation within different viruses. Such coevolution proposes the existence of immune response mechanism against these sub-genomic organisms, and further suggests adaptive plant-pathogen interactions, something that is known as host specificity. Herein, it was also speculated that some miRNA families such as; miR915, miR899 and miR895 with unknown or non-validated targets in plant genomes are being involved in suppression of invading viruses/viroids.

The role of MicroRNAs in defense against viral phytopathogens

MicroRNAs have been considered as an endogenous post-transcriptional gene silencing mechanism for transcription regulation. Additionally, reports are indicative of their involvement in plant viral defense. It seems that horizontal miRNA transfer from pathogenic viral and viroid genomes into plants has evolved into the counter-defense mechanism(s) against their invasions. miRNAs of a green alga and 16 other higher plant species, with/without endogenous function, were searched for their energetically favorable target sites in the complete genomes of plant-specific invading viruses and viroid. Interestingly, 6524 and 250 putative target sites were found in 759 viral and 16 viroid genomes, respectively. Also, in 5589 viral sequence or viral encoding genes, we found 7583 putative target sites from 638 plant invading viruses to be targeted by 1019 miRNAs (belonging to 636 MIRNA families). The evidence of viral/viroid miRNAs targeting plant transcriptome was lacking. The data were indicative that in only 33–40% of the cases of plant miRNAs-viral/viroid targets translation arrest occurs. Some of the MIRNA families including MIR171, MIR156, and MIR159 had a wide target range in viral genomes suggesting possible plant-virus coevolution and at the same time a degree of conservation within different viruses. This putative coevolution could suggest of immune response mechanism against these sub-genomic organisms and further suggests adaptive plant-pathogen interactions, something that is known as host specificity. Herein, we have also speculated that some MIRNA families such as; MIR915, MIR899, and MIR895 with unknown or non-validated targets in plant genomes are being involved in suppression of invading viruses/viroid.

Bioinformatical Analyses of cinnamyl alcohol dehydrogenase (CAD) proteins from higher plant species

Cinnamyl alcohol dehydrogenase (CAD) (EC 1.1.1.195) is an enzyme functioning in the reduction of various phenylpropenyl aldehyde derivatives which are precursors in lignin and lignan production. Species-specific CAD genes have been extensively identified in recent years. In this study, we used bioinformatics tools to characterize and classify plant CADs. The amino acid and nucleotide sequences of 16 CADs from different plant species were used to compare their physiological properties, phylogeny, and conserved motifs. For this purpose, sequence, phylogenetical, structural analyses of proteins were conducted using various servers. All plant CADs had the characteristic alcohol dehydrogenase (PF08240) and zinc-binding dehydrogenase domains (PF00107). According to the physicochemical analysis, it was revealed that the most of plant CADs (81.25%) were in acidic character. Sequence length (aa) and molecular weight (kDa) of CAD proteins were found in range of 356 -367 and 38.6-40.5 respectively. The highest sequence similarities were found between Sorghum bicolor and Zea mays (95.3%), Panicum virgatum and Sorghum bicolor (90.9%), and Oryza sativa and Zea mays (87.1%) respectively. Plant CADs showed divergent exon-intron structures in which exon numbers were ranged from two to six. Four monocot species (S. bicolor, P. virgatum, Z. mays, and O. sativa) have four exons, whereas Brachypodium distachyon contains only two exons. Phylogenetic analysis revealed that the CAD proteins mainly divided into two groups. The highest bootstrap values were found as follows: Fragaria vesca-Prunus persica clade (100%), Glycine maxMedicago truncatula (81%), and S. bicolor-Z. mays (72%). The 3D structures of plant CADs showed that Oryza and Vitis had the most divergent structures when compared to the other plant species. Eventually, the data represented here contribute to studies aiming at evaluating the plant CADs extensively and at identifying new CAD genes in other plants.

Structural introspection of a putative fluoride transporter in plants.

The xenobiotic fluoride is a detrimental toxin which is exported by a double-barrelled fluoride channel (Fluc) in prokaryotes and a single-barrelled fluoride exporter (FEX) in lower eukaryotes. The presence of FEX gene in higher plant species has not been reported till date. In this communication, we have identified FEXs across nine plant species belonging to five different families. Homology modelling predicted the sequential and structural conservation of crucial residues in plant FEXs. It was predicted that the N-terminal segments were the main target sites for phosphorylation. Other post-translational modifications included Arg methylation, Lys acetylation and Cys S-nitrosylation, all of which contribute to protein stability and function. FEXs were predicted to contain lipid moieties which anchor the transporters to the plasma membrane. The crystallizability along with associated properties of plant FEXs was also analyzed to facilitate future experimental analyses. The predicted RNA structure of OsFEX formed several pseudoknots, though no riboswitches could be detected from our prediction. The analysis of upstream regions of FEX in representative plants represented that this gene could be responsive to phytohormone-mediated signaling. This is the first novel report highlighting that FEX genes in plants are probably expressed in a tissue-specific pattern and possibly via a phytohormone-dependent pathway to encode functional FEX proteins during fluoride stress.

Cardenolide Intake, Sequestration, and Excretion by the Monarch Butterfly along Gradients of Plant Toxicity and Larval Ontogeny.

Monarch butterflies, Danaus plexippus, migrate long distances over which they encounter host plants that vary broadly in toxic cardenolides. Remarkably little is understood about the mechanisms of sequestration in Lepidoptera that lay eggs on host plants ranging in such toxins. Using closely-related milkweed host plants that differ more than ten-fold in cardenolide concentrations, we mechanistically address the intake, sequestration, and excretion of cardenolides by monarchs. We show that on high cardenolide plant species, adult butterflies saturate in cardenolides, resulting in lower concentrations than in leaves, while on low cardenolide plants, butterflies concentrate toxins. Butterflies appear to focus their sequestration on particular compounds, as the diversity of cardenolides is highest in plant leaves, lower in frass, and least in adult butterflies. Among the variety of cardenolides produced by the plant, sequestered compounds may be less toxic to the butterflies themselves, as they are more polar on average than those in leaves. In accordance with this, results from an in vitro assay based on inhibition of Na+/K+ ATPase (the physiological target of cardenolides) showed that on two milkweed species, including the high cardenolide A. perennis, extracts from butterflies have lower inhibitory effects than leaves when standardized by cardenolide concentration, indicating selective sequestration of less toxic compounds from these host plants. To understand how ontogeny shapes sequestration, we examined cardenolide concentrations in caterpillar body tissues and hemolymph over the course of development. Caterpillars sequestered higher concentrations of cardenolides as early instars than as late instars, but within the fifth instar, concentration increased with body mass. Although it appears that large amounts of sequestration occurs in early instars, a host switching experiment revealed that caterpillars can compensate for feeding on low cardenolide host plants with substantial sequestration in the fifth instar. We highlight commonalities and striking differences in the mechanisms of sequestration depending on host plant chemistry and developmental stage, which have important implications for monarch defense.

Planting gardens to support insect pollinators.

Global insect pollinator declines have prompted habitat restoration efforts, including pollinator-friendly gardening. Gardens can provide nectar and pollen for adult insects and offer reproductive resources, such as nesting sites and caterpillar host plants. We conducted a review and meta-analysis to examine how decisions made by gardeners on plant selection and garden maintenance influence pollinator survival, abundance, and diversity. We also considered characteristics of surrounding landscapes and the impacts of pollinator natural enemies. Our results indicated that pollinators responded positively to high plant species diversity, woody vegetation, garden size, and sun exposure and negatively to the separation of garden habitats from natural sites. Within-garden features more strongly influenced pollinators than surrounding landscape factors. Growing interest in gardening for pollinators highlights the need to better understand how gardens contribute to pollinator conservation and how some garden characteristics can enhance the attractiveness and usefulness of gardens to pollinators. Further studies examining pollinator reproduction, resource acquisition, and natural enemies in gardens and comparing gardens with other restoration efforts and to natural habitats are needed to increase the value of human-made habitats for pollinators.

Topsoil mixing or fertilization? Forest flora changes in the vicinity of badgers\u2019 (Meles meles L.) setts and latrines

AimsThe badgers may affect soil chemical properties and plant species composition in two ways: by digging burrows (topsoil mixing) and by using latrines (fertilized soils). Here is reported which kind of badgers’ activity plays a major role.MethodsSoil samples for pH, total N, NH4+, NO3− and data concerning plant species composition were collected on circular plots (N = 80) on burrow mounds, latrines and reference areas.ResultsBurrow mounds were characterized by higher pH and lower content of total N. The content of NH4+ − main component of manure, was higher in latrines than on mounds, whereas in the case of mounds, the content of NO3− was higher than in latrines. There was higher plant species richness on the burrow mounds than on the other plot types. Also plant species characterized with traits allowing them to settle on disturbed habitats were recorded at a higher number on burrow mounds. CCA analysis distinguished only one herbaceous plant aggregation associated with burrow mounds. The presence of latrines with high rate of nitrogen input did not affect plant species composition due to a low rate of soil mixing.ConclusionsSoil chemical properties and flora changes showed that badgers shape plant communities not by fertilization with excrements but, as a result of digging activity, by altering topsoil conditions.

Review on Effects of Land Use Land Cover Change on Plant Species Composition, The Case of Ethiopia

Land use is the purpose to which land is put by humans (protected areas, forestry for timber products, plantations, row-crop agriculture, pastures, or human settlements). Land cover is the ecological state and physical appearance of the land surface (closed forests, open forests, grasslands). Land use change is when the use of a particular land is changed from one to another over time, (from natural vegetation (forest) to cultivation; cultivation to grazing or from swamp to cultivation). Ethiopia has the fifth largest floral diversity in tropical Africa. Between; 6,000-7,000 species of higher plants are estimated to exist in the country of which about 780-840 (12-13%) plant species are estimated to be endemic. Ethiopia is one of the most populous countries in Africa, which is experiencing huge land use land cover (LULC) dynamics from natural vegetation to farming practices and human settlement. Existing sources indicate that about 40% of the country’s land area was covered with dense forests at the turn of the 20th century. However, the forest coverage has reached a low level of 3.56%. Agricultural expansion is, by far, the leading land-use change associated with nearly all deforestation cases (96%) while energy consumption, infrastructure development involves both settlement expansion as well as the expansion of transport networks were also the major factor driving land use land cover change and resulting in Ethiopian plant species biodiversity loss. So that, estimation of land use impacts on biodiversity, especially at landscape scale, is necessary to ensure systematic conservation planning and designing sound land use management system. Keywords : Land use, Land cover, Plant species diversity, Biodiversity DOI : 10.7176/JBAH/9-3-05

Bacterial communities associated to Chilean altiplanic native plants from the Andean grasslands soils

The rhizosphere is considered the primary place for soil microbiome differentiation and plays a key role in plant survival, especially for those subjected to environmental stress. Using high-throughput sequencing of the 16S rRNA gene, we analyzed and compared soil bacterial communities associated to four of the most abundant high altitude native plant species of the Chilean Andean grasslands. We examined three soil compartments: the rhizosphere (bacteria firmly attached to the roots), the rhizosphere-surrounding soil (bacteria loosely attached to the roots) and the bulk soil (plant-free soil). The rhizosphere microbiome was in all cases the least diverse, exposing that the bulk soil was a more complex environment. Taxonomic analysis revealed an abrupt change between the rhizosphere and the rest of the non-rhizospheric soils. Thus, while rhizobacterial communities were enriched in Proteobacteria (mainly Alphaproteobacteria), Actinobacteria (mostly Blastocatellia) dominated in bulk soils. Finally, we detected certain taxonomic rhizosphere signatures, which could be attributed to a particular genotype. Overall, our results indicate that the thin layer of soil surrounding the roots constitute a distinctive soil environment. This study contributes to expand the knowledge about soil bacterial communities in the Chilean highlands and takes the first step to understand the processes that might lead to the rhizosphere differentiation in that area.

Predatory arthropods in apple orchards across Europe: Responses to agricultural management, adjacent habitat, landscape composition and country

Local agri-environmental schemes, including hedgerows, flowering strips, organic management, and a landscape rich in semi-natural habitat patches, are assumed to enhance the presence of beneficial arthropods and their contribution to biological control in fruit crops. We studied the influence of local factors (orchard management and adjacent habitats) and of landscape composition on the abundance and community composition of predatory arthropods in apple orchards in three European countries. To elucidate how local and landscape factors influence natural enemy effectiveness in apple production systems, we calculated community energy use as a proxy for the communities’ predation potential based on biomass and metabolic rates of predatory arthropods. Predator communities were assessed by standardised beating samples taken from apple trees in 86 orchards in Germany, Spain and Sweden. Orchard management included integrated production (IP; i.e. the reduced and targeted application of synthetic agrochemicals), and organic management practices in all three countries. Predator communities differed between management types and countries. Several groups, including beetles (Coleoptera), predatory bugs (Heteroptera), flies (Diptera) and spiders (Araneae) benefited from organic management depending on country. Woody habitat and IP supported harvestmen (Opiliones). In both IP and organic orchards we detected aversive influences of a high-quality surrounding landscape on some predator groups: for example, high covers of woody habitat reduced earwig abundances in German orchards but enhanced their abundance in Sweden, and high natural plant species richness tended to reduce predatory bug abundance in Sweden and IP orchards in Spain. We conclude that predatory arthropod communities and influences of local and landscape factors are strongly shaped by orchard management, and that the influence of management differs between countries. Our results indicate that organic management improves the living conditions for effective predator communities.

Which spatial distribution model best predicts the occurrence of dominant species in semi-arid rangeland of northern Iran?

Rangelands with more than 8000 plant species occupy nearly 54.6% of the land area of Iran and thus are accounted for a rich plant genetic storage. Mazandaran province has 378,000 ha of rangelands with high plant species richness and diversity due to its climate conditions but plants distribution is at risk because of non-principle management, land use change and as a result changing environmental factors. Vegetation management strategies can be guided by models that predict plant species distribution based on governing environmental variables. This is especially useful for the dominant species that determine ecosystem processes. In fact, modelling algorithm in each SDM determines its suitability for different ecosystems. Our aim was to compare the predictive power of a number of SDMs and to evaluate the importance of a range of environmental variables as predictors in the context of semi-arid rangeland vegetation. The selected study area, the Sarkhas rangelands (northern Iran, 36°10′ 42˝ N - 51°19′ 11˝ E), covers approximately 4358.9 ha of Mazandaran province. The efficacy of four different modelling techniques as well as Ensemble model was evaluated to predict the distribution of five dominant forage plant species (Vicia villosa, Stachys lavandulifolia, Coronilla balansae, Sanguisorba minor and Alopecurus textilis). The used models included artificial neural network (ANN), boosted regression trees (BRT), classification and regression trees (CART), and random forest (RF). Ensemble, RF and CART had the highest area under curve. The AUC obtained for Vicia villosa, Stachys lavandulifolia, Coronilla balansae, Sanguisorba minor and Alopecurus textilis, were 0.90, 0.72, 0.76, 0.69 and 0.75 respectively. Ensemble model was the model that most consistently demonstrated high predictive power across species in the rangeland context investigated here. BRT exhibited the least predictive power. An importance analysis of variables showed that soil organic C according to the CART model (0.396) and K according to the RF model (0.396) were the most important environmental variables.

The role of natural products in modern drug discovery.

The global medicine market is about 1.1 trillion US dollars. About 35 percent of medicines have originated from natural products. Brazil presents the largest biodiversity in the world, with more than 50,000 species of higher plants. However, few innovative products have been developed in Brazil from active constituents derived from the Brazilian biodiversity. Scientific evidences on plants and venoms have been internationally published by Brazilian scientists over the last 4 decades; but few examples of innovative products are commercially available. Few examples include the anti-hypertensive drug captopril first identified in the venom of the Brazilian viper Bothrops jararaca by Professor Sergio Ferreira; and some phytotherapeutic agents such as Acheflan®, Syntocalmy® and Melagrião® produced by standardized plant extracts with scientific proof of safety, efficacy and quality. Still, only Acheflan® and Melagrião® are obtained from native Brazilian plants. Several issues contribute to the lack of innovative products from the Brazilian biodiversity, but in my opinion, the most challenging ones are i) the lack of specific regulations to allow researchers and companies to access biodiversity for the purposes of scientific and technological innovation; and ii) the absence of a long-term government program to support research and innovation in this field.

Comparative Analysis of Copper and Cadmium Accumulation by Macrophytes of the Chupa Inlet, Kandalaksha Bay, White Sea

The content of dry matter, copper (Cu), and cadmium (Cd) have been studied in five species of brown algae and one species of higher plants at six sampling sites in the Chupa Inlet of the Kandalaksha Bay of the White Sea. Despite a common natural geochemical background, a variability in the content of Cu and Cd has been observed in algae species which have similar systematic positions. No simple functional relationship could be established between the dry matter content and content of metals. Copper affects the accumulation of cadmium only when the Cu content is high. Species of the family Fucaceae (Fucus vesiculosus, F. serratus, and Pelvetiacanaliculata) accumulated Cu and Cd most effectively. The minimum content of Cd was found in the leaves of Triglochinmaritimum.