Intestinal ciliate fauna of the Asian elephant from Gaziantep,Turkey and the description of Brevitentaculum antebum n. g., n. sp.

The aims of this investigation were to identify and quantify ciliates inhabiting the large intestine of Asian elephants living in Gaziantep Zoo, Turkey, and to describe a new suctorian genus and species. Species composition and distribution of intestinal ciliates voided in the feces of two Asian elephants were examined. Fifteen species of intestinal ciliates, representing 7 genera, were identified. One new suctorian genus and species, Brevitentaculum antebum n. g., n. sp., was described. This new species has two short truncated terminal projections, with two longitudinally lined bands located between the two projections, near the convex surface of the cell. Short clavate-like tentacles are in two fascicles near each base of terminal projections on the flattened surface of the body. Ciliate densities in the two fecal samples were 4.5 × 10⁴ mL⁻¹ and 10 × 10⁴ mL⁻¹.     

Relative growth rate,biomass partitioning and nutrient allocation in seedlings of two threatened trees grown under different light conditions

The present study investigates the variation in the relative growth, biomass and nutrient allocation in two threatened tree species viz. Magnolia punduana Hook.f. & Th. and Elaeocarpus prunifolius Wall. ex Müll. Berol. grown under three different levels of irradiance. The irradiance ranged between 1 and 12 mol m^?2 d^?1. Results showed that the highest relative growth rate (RGR) was achieved under the intermediate light treatment for both the species (mean: 0.005 mg mg^?1 d^?1). The growth response coefficient (GRC) model revealed that net assimilation rate (NAR) was the factor driving the RGR in both species. A significant positive correlation was found between NAR and RGR (R² = 0.33, p = 0.000) whereas specific leaf area (SLA) and leaf mass fraction (LMF) was negatively correlated to RGR. Overall, multiple regression of the studied species based on the independent variables viz. NAR, SLA, and LMF showed a significant relation with RGR (F(3,50,53 = 13.001, p = 0.000, R² = 0.43). The biomass distribution in the studied species is in agreement with the “balanced-growth hypothesis” where high irradiance increased allocation to below ground biomass fraction and decreased irradiance increased allocation to the above ground fraction. The highest nitrogen concentration in leaves was observed under the intermediate light treatment. Overall seedlings growth under intermediate light had a higher mean RGR indicating the species' preference for partial light conditions. Long-term experiments under varied light conditions as in the present study would provide useful insight into plant growth strategies in varied environmental conditions.     

Anmerkungen zur Haltung von Asiatischen Kurzkrallenottern (Amblonyx cinereus) in Zoologischen Gärten Europas

We report on keeping conditions of the Asian small-clawed otter Amblonyx cinereus in European Zoos. In 2007 434 individuals were kept in 86 Zoos. 50% of these zoos keep their otters in groups from seven up to 21 individuals, similarly as suggested for the wild. The area available for each individual in 51 enclosures ranges from 5.2 m² to 464 m² in enclosures, where otters are held together with larger animals (apes, lions etc.).     

Treatment of domestic wastewater in tropical,subsurface flow constructed wetlands planted with Canna and Heliconia

Constructed wetlands have a good potential for wastewater treatment in developing countries due to the simple operation and low implementation costs. Ornamental plants like Canna and Heliconia are used in the wetlands to increase their aesthetic value and these two species were compared in this study. Six pilot scale horizontal subsurface flow constructed wetland units were constructed at the Asian Institute of Technology (AIT) campus in Bangkok, Thailand, of which three were planted with Heliconia psittacorum L.f. × H. Spathocircinata (Aristeguieta) and three with Canna × generalis L. Bailey. The beds were loaded with domestic wastewater in four trials with hydraulic loading rates ranging from 55 to 440 mm d^?1 corresponding to nominal detention times between 12 h and 4 days. Both plant species grew well in the systems and especially Canna had high growth rates (3100 ± 470 g DW m^?2 yr^?1) compared to Heliconia (550 ± 90 g DW m^?2 yr^?1). TSS mass removal rates were very high with efficiencies >88% even at hydraulic loading rates of 440 mm d^?1. COD mass removal rates varied between 42 and 83% depending on the loading rates. The removal rate constants for COD as fitted by the first-order k–C^* model were estimated to be 0.283 and 0.271 m d^?1 for Canna and Heliconia beds, respectively (C^* = 28.1 and 26.7 mg l^?1). Removals of nitrogen (N) and phosphorus (P) were low compared to the loading rates, but removal of total-N was higher in the beds planted with Canna than in beds with Heliconia because of the higher growth rate of Canna. It is concluded that ornamental species like Canna and Heliconia can be used to enhance the aesthetic appearance and hence the public acceptance of wastewater treatment systems in tropical climates. Canna is the preferred species from a treatment perspective because of its more vigorous growth, but since Heliconia has an economic potential as cut flowers may be preferred in many cases.     

Structural indicators of richness and rarity of epiphytic lichens on Corylus avellana in two different forest types within a nature reserve in south-western Norway

Abstract:Epiphytic lichens (and some non-lichenized fungi) on 34 coppices (204 stems) ofCorylus avellana were investigated in a 140 ha study area in south-western Norway. A total of 65 species were recorded on a total bark area of 63 m². Corylus in broad-leaved deciduous forest supported more species of macrolichens, and fewer species of microlichens, than Corylus in pine forest. The macrolichen flora of the deciduous forest differed from that of the pine forest by having a rich flora of species belonging to the Lobarion alliance. OldCorylus coppices with tall stems (>8 m), large girth (>8 cm diameter at breast height) and a noticeable cover of macrolichens (>10% of bark area) supported the highest number of rare species, and overall, species of macrolichens. More than 50% cover of microlichens indicated richness and rarity of microlichens on Corylus.     

Dispersal pattern of airborne emissions from an aluminium smelter in Ouro Preto,Brazil, as expressed by foliar fluoride accumulation in eight plant species

In order to evaluate the dispersal pattern of airborne fluoride emissions, from a single source in the city of Ouro Preto, Brazil, the fluoride impact on some herbaceous plant species was studied using the plants as passive bioindicators. Foliar fluoride contents of eight species collected at different distances from an aluminium smelter were analyzed. The plant species were: Baccaharis dracunculifolia, Bidens pilosa, Borreria verticillata, Calopogonium mucunoides, Erigeron bonariensis, Hedychium coronarium, Ipomoea purpurea and Ipomoea cairica. In all species the fluoride accumulation decreased exponentially with the distance from the emission source. There was specific and distinct variation in fluoride accumulation among the species, a group of high-accumulator species (B. dracunculifolia and Bidens pilosa) and a group of low-accumulator species (I. cairica, H. coronarium and Borreria verticillata). C. mucunoides and E. bonariensis occupied an intermediate position. There was a pattern of plant contamination response during the periods analyzed. The plants nearest to the emission source, between 0.4 km northwest and 1.1 km east, showed fluoride contamination traits in leaves reaching values between 100 and 500 μg g⁻¹. Moreover, fluoride contents higher than 1000 μg g⁻¹ were found in these plants. At the most distant stations, situated 2.9 km northwest and 6 km east from the factory, the fluoride content of the dry matter was less than 10 μg g⁻¹ showing that plants at those distances were submitted to minimum contamination. There were different patterns of tolerance among the species analyzed. While B. dracunculifolia accumulated fluoride up to 1500 μg g⁻¹ in dry matter without any signs of injury, Borreria verticillata showed severe necrosis in leaves, but the fluoride content found was not higher than 120 μg g⁻¹.     

Diversity and spatial clustering of shade trees affect cacao yield and pathogen pressure in Costa Rican agroforests

The importance of the spatial organisation of individuals in explaining species coexistence within a community is widely recognised. However, few analyses of spatial structure have been performed on tropical agroforests.The main objective of this study was to highlight the links between spatial organisation of shade trees on the one hand, and shade tree species richness and cacao yield on the other, using data from 29 cacao agroforests in Costa Rica.A method of spatial statistics, Ripley's K-function, was used to analyse the spatial organisation of shade and cacao trees in the study plots. For each stand, the X and Y coordinates of ≥2.5-m-tall trees were recorded. In each plot we also assessed shade tree species richness and cacao yield (with total number of pods = number of pods damaged by frosty pod rot + number of healthy pods).Three types of stands were identified: the first was characterised by significant clustering of shade trees, the highest shade tree species richness (S = 6), and the highest number of damaged pods (139 pods ha^?1 year^?1). The second type was characterised by random spatial organisation of shade trees. The third type showed a trend towards regular organisation. Species richness of shade trees did not differ significantly between the last two types (S = 4 for both), nor did the number of damaged pods (56 pods ha^?1 year^?1 and 67 pods ha^?1 year^?1 respectively).Although the trends were not statistically significant for all the variables in our data set, the clustered spatial structure appears to favour a synergy between environmental (tree species richness), and provisioning (cacao production) services.     

Vibrio aestivus sp. nov. and Vibrio quintilis sp. nov., related to Marisflavi and Gazogenes clades,respectively

Two new Vibrio species, Vibrio aestivus and Vibrio quintilis, are described after a polyphasic characterization of strains M22^T, M61 and M62^T, isolated from seawater collected off a beach on the East coast of Spain (Valencia). All three strains are Gram negative, mesophilic, slightly halophilic, fermentative rods. V. aestivus (M22^T = CECT 7558^T = CAIM 1861^T = KCTC 23860^T and M61 = CECT 7559 = CAIM 1862 = KCTC 23861) is oxidase positive, reduces nitrates to nitrites, is negative for Voges Proskauer, arginine dihydrolase and indole and non hydrolytic on most substrates tested. The 16S rRNA gene sequences of M22^T and M61 are most similar to Vibrio marisflavi (97.1–97.2%) but phylogenetic analysis using NJ, MP and ML methods display Vibrio stylophorae (96.2% similarity) as sibling species. The three species form a deep clade in the genus Vibrio. Average Nucleotide Identity (ANI) values, determined as a measure of overall genomic resemblance, confirmed that strains M22^T and M61 are members of the same species, different to V. marisflavi CECT 7928^T.V. quintilis (M62^T = CECT 7734^T = CAIM 1863^T = KCTC 23833^T) is aerogenic, arginine dihydrolase and Voges Proskauer positive, oxidase negative and unable to reduce nitrate, traits shared by most species in the Gazogenes clade. It is unpigmented and does not grow on TCBS Agar. 16S rRNA gene similarities to its nearest species, Vibrio aerogenes and Vibrio mangrovi, are 97.6% and 96.0% respectively. Strain M62^T and V. aerogenes CECT 7868^T display ANI values well below the 95% boundary for genomic species.     

Testing the effectiveness of surrogates for assessing biological diversity of arthropods in cereal agricultural landscapes

Agricultural intensification is altering biodiversity patterns worldwide. Rapid and effective methods are needed to monitor these changes in farmland biodiversity, but it becomes both a cost- and time-prohibitive task, particularly for hyper-diverse groups such as arthropods. We evaluated the effectiveness of surrogates in irrigated and rainfed wheat fields in a Mediterranean farmland in NW Spain in order to get a rapid tool to assess arthropod biodiversity. We studied six groups with different ecological needs (i.e. Aphididae, Aphidiinae, Coccinellidae, Formicidae, Heteroptera and Syrphidae) at species level (147 species), genus (105), family (10, only Heteroptera) and order (19) level. Higher taxa, cross-taxa and subset-taxa or total richness approaches were tested as well as the correlation in composition between levels for the selected groups, and the influence of farming regime. Genus richness was a good surrogate of species richness in all six groups studied (R² = 0.38–0.60), like family and order were for Heteroptera (R² = 0.37 and 0.29, respectively). Cross-taxa analyses showed that Aphididae and Aphidiinae genera (R² = 0.19 and 0.30, respectively) and species (R² = 0.20 and 0.28, respectively) were good surrogates for Aphidiinae and Aphididae species respectively. Coccinellidae genera (R² = 0.26) and species (R² = 0.25) were good surrogates for Heteroptera species. Finally, Aphididae and Coccinellidae both at genera (R² = 0.14 and 0.20, respectively) and at species levels (R² = 0.12–0.22, respectively) were good surrogates for total species richness of all groups. Genera composition was the best surrogate for the species composition within each group. Farming regime had no influence on the relationships between surrogates and species patterns in most cases. Our results suggest that genera level is a useful surrogate for all the studied groups and family is appropriate for Heteroptera. Genus level provided a saving of 15% of identification time in Aphididae and 80% for Coccinellidae. This proves its usefulness to asses and monitor biodiversity in wheat croplands and the possibility to reduce costs.     

Altitude modifies species richness–nutrient indicator value relationships in a country-wide survey of grassland vegetation

Nutrient enrichment is a threat to botanical diversity in Europe, and its assessment is part of biodiversity monitoring schemes. In Switzerland, this is done by calculating the average nutrient (N) indicator value of the vegetation based on a country-wide systematic vegetation survey. However, it is questionable whether N values indicate eutrophication and resulting species loss equally well across an entire country, which includes wide topographic gradients and distinct biogeographic regions. Here we analyze vascular plant species lists from 415 grassland plots (10 m²) between 365 and 2770 m a.s.l. throughout Switzerland to investigate how the relationship between N value and species richness differs with altitude and among regions. The N value strongly decreased with altitude (piecewise regression: r² = 0.77), particularly between 800 and 2000 m a.s.l., where this decrease was related to a decreasing proportion of fertilized grasslands. In the alpine belt, lower N values were associated with a greater frequency of acidic soils and a restricted species pool. Vascular plant species richness was maximal at intermediate altitude (piecewise regression: r² = 0.33) and intermediate N value (polynomial regression: r² = 0.46). When analyzed separately by altitudinal belt, the relationship between species richness and N value was negative in the lowlands and montane belt but unimodal in the subalpine belt. In the alpine belt, soil pH (R indicator values) explained most of the variation in species richness. Two indices of between-plot diversity (floristic dissimilarity and the contribution of individual plots to total species richness) were negatively related to N values from the lowlands to the subalpine belt but not in the alpine belt. All relationships differed little among the biogeographic regions of Switzerland, but they might be modified by changes in management and by the expansion of common lowland species into mountain grasslands.     

Towards an optimal sampling strategy for Alexandrium catenella (Dinophyceae) benthic resting cysts

The study proposes methodological developments to optimize sampling strategy of resting cysts of Alexandrium catenella to estimate their abundance with a predefined error. This work also aims to provide information on spatial distribution of resting cysts in sediments. The distribution mode of A. catenella resting cysts related to the abundance variability was studied through sediment cores sampling on four different spatial scales and using Ludox CLX gradient density method. The quantification method underestimates by a factor of 2 the resting cysts abundance in one gram of sediment. Application of Taylor's power law allowed us to define a compromise between sampling effort and abundance estimation error. In the case of A. catenella resting cysts from Thau lagoon, the optimal sampling strategy consists of sampling 10 stations on a surface of 2 km² for a given coefficient of variability (C) of 15%, sampling 3 sediment cores at each station (C = 30%) and counting only one replicate by core (C = 18%). Results related to the application of Taylor's power law are closely dependent on resting cyst density and aggregation in a given sediment. In our area, A. catenella resting cysts are mainly observed in the upper 3 cm of sediment. Horizontally, their heterogeneity is lower on 10 cm² surface and tends to stabilize itself beyond a surface of 10 m². Each author has to carry out this pre-sampling effort for his own resting cysts-forming species, in his own area, in order to increase accuracy of resting cyst mapping.     

The seed bank in a subtropical freshwater marsh: implications for wetland restoration

Seed bank samples were collected from Huli Marsh, a subtropical shallow water mountainous marsh in Hunan Province, South China. Core samples were divided into upper and lower layers (each 5 cm in depth) and allowed to germinate in three water levels (0, 5 and 10 cm) over a 4-month period. A total of 51 species germinated and the mean density was 9211 ± 7188 seedlings m⁻². In the top 5 cm 41 species and 5747 ± 5111 seedlings m⁻² germinated, whereas 40 species and 3464 ± 3363 seedlings m⁻² did so from 5–10 cm. Germinated seedling density was significantly higher in the upper layer, largely due to differences in eight species. With increasing experimental water depth, less seedlings germinated: respectively, 9788 ± 7157 m⁻², 2050 ± 2412 m⁻² and 1978 ± 2616 m⁻², of 44, 21 and 19 species, submerged under 0, 5 or 10 cm. Seven species could emerge only in 0 water level. Vallisneria natans occurred only in 5 cm water, whereas Ottelia alismoides occurred in 10 cm water. In the vegetation survey of the marsh, 25 species were recorded, which was less than half of the species recorded in the seed bank. The top 10 dominants in the standing vegetation, accounting for 89% of vegetation abundance, represented only 10% in the seed bank. Twenty germinated species that also occurred in the standing vegetation accounted for 56% of the total seed bank. Our observed number of species germinating from a Chinese wetland seed bank is within the range observed elsewhere in the northern hemisphere (15–113 species).     

Diversity and heavy metal tolerance of endophytic fungi from six dominant plant species in a Pb–Zn mine wasteland in China

The diversity and metal tolerance of endophytic fungi from six dominant plant species in a Pb–Zn mine wasteland in Yunnan, China were investigated. Four hundred and ninety-five endophytic fungi were isolated from 690 tissue segments. The endophytic fungal colonization extent and isolation extent ranged from 59 % to 75 %, and 0.42–0.93, respectively, and a positive correlation was detected between them. Stems harboured more endophytic fungi than leaves in each plant species, and the average colonization extent of stems was 82 %, being significantly higher than that of leaves (47 %) (P ≤ 0.001, chi-square test). The fungi were identified to 20 taxa in which Phoma, Alternaria and Peyronellaea were the dominant genera and the relative frequencies of them were 39.6 %, 19.0 % and 20.4 %, respectively. Metal tolerance test showed that 3.6 mM Pb²⁺ or 11.5 mM Zn²⁺ exhibited the greatest toxicity to some isolates and they did not grow on the metal-amended media. In contrast, some isolates were growth stimulated in the presence of tested metals. The isolates of Phoma were more sensitive to Zn²⁺ than the isolates of Alternaria and Peyronellaea. However, the sensitivity of isolates to Pb²⁺ was not significantly different among Phoma, Alternaria, Peyronellaea and other taxa (P > 0.05, chi-square test). Our results suggested that fungal endophyte colonization in Pb–Zn polluted plants is moderately abundant and some isolates have a marked adaptation to Pb²⁺ and Zn²⁺ metals, which has a potential application in phytoremediation in this area.     

Abundance and distribution of toxic Alexandrium tamarense resting cysts in the sediments of the Chukchi Sea and the eastern Bering Sea

Abundance and distribution of the toxic dinoflagellate Alexandrium tamarense species complex resting cyst were investigated in the eastern Bering Sea and the Chukchi Sea for the first time. Sediment samples (top 0–3 cm depth) were collected from the continental shelf of the eastern Bering Sea (17 stations) and the Chukchi Sea (13 stations) together with a long core sample (top 0–21 cm depth) from one station in the Chukchi Sea during 2009–2012. The cysts were enumerated using the primuline staining method. Species identification of the cysts was carried out with multiplex PCR assay and the plate morphology of vegetative cells germinated from cysts in the both areas. Alexandrium cysts were widely detected in the both areas, ranging from not detected (<1 cysts cm⁻³) to 835 cysts cm⁻³ wet sediment in the eastern Bering Sea and from not detected (<1 cysts cm⁻³) to 10,600 cysts cm⁻³ in the Chukchi Sea, and all isolated cysts were genetically and morphologically identified as the North American clade A. tamarense. Their cysts were mainly distributed in the shallow continental shelf where the water depth was less than 100 m in both areas. The cysts were detected from the deep layer (18–21 cm depth of sediment core) of the long core sample. The present study confirmed the abundant existence of A. tamarense with wide range of distribution in these areas. This fact suggests that A. tamarense vegetative cells have appeared in the water column in the both areas. Furthermore, these abundant cyst depositions indicate that this species originally distributed in the Arctic and subarctic regions and well adapted to the environments in the marginal ice zone.     

Increasing nitrogen depositions can reduce lichen viability and limit winter food for an endangered Chinese monkey

Increasing economic growth and industrial development in China is starting to impact even remote areas such as the Shennongjia nature reserve, where nitrogen pollution is becoming a major environmental threat. The epiphytic lichen flora is particularly rich in this area and is one of the components of this habitat most sensitive to nitrogen pollution. Since lichens represent an important food resource for the endangered monkey species Rhinopithecus roxellana, a reduction in lichen availability would have harmful consequences for the conservation of its habitat in the Shennongjia Mountains. To investigate the effects of increased nitrogen availability on the local lichen communities, so far scarcely considered, we conducted a one-year field experiment measuring growth, survival, and phosphomonoesterase activity of the widespread species Usnea luridorufa in response to nitrogen (up to 50 kg N ha⁻¹ year⁻¹ deposition) and phosphorus supply. Growth and survival of thalli and propagules of U. luridorufa decreased when treated with N deposition >12.05 kg N ha⁻¹ year⁻¹ and >2.14 kg N ha⁻¹ year⁻¹, respectively. The important role of phosphorus availability in relation to nitrogen supply was demonstrated by the increase in phosphomonoesterase activity with increasing nitrogen availability until a nitrogen toxicity threshold was reached. However, the high concentration of phosphorus in rainwater showed that phosphorus is not a limiting nutrient in the area.The results make a contribution to the knowledge of the negative effects of increased N deposition in the Shennongjia forest ecosystem.     

Temperature and rate of seed consumption by ground beetles (Carabidae)

Predation is a key source of seed mortality in many weed species and thus is a part of natural control. In the field, the intensity of seed predation by invertebrates varies during the course of a year. One source of this variation is fluctuations in ambient temperature. Here, the effect of temperature on seed consumption is investigated for the first time, using two abundant carabid seed predators, Pseudoophonus rufipes and Harpalus affinis (Coleoptera: Carabidae), and dandelion (Taraxacum officinale) as a model system. Field collected individuals were sexed, kept at one of six constant temperatures between 10 and 28 °C and provided with a surplus of seed. Seed consumption was recorded over a period of 4 days. Averaged over all the temperatures, the smaller H. affinis consumed 12.2 seeds day^?1 and larger P. rufipes 29 seeds day^?1. On average, females consumed more seeds than males. Seed consumption by both species increased with temperature. In H. affinis the increase was linear and different for males and females. In P. rufipes the consumption was similar in both sexes but curvilinear because there was no further increase in consumption above 20 °C. Assuming a linear relationship between temperature and consumption at up to 20 °C we calculated the temperature at which seed consumption ceased (?0.1 to 0.3 °C in H. affinis and 6.3–6.9 °C in P. rufipes) and the increment in seed consumption per 1 °C increase in temperature above this threshold (0.4–1.0 and 1.5–4.2 seeds individual^?1 day^?1, respectively) for the two species. Thus, it is possible to calculate the average daily consumption of each species over a range of temperatures up to 20 °C.     

The relationship between Pseudo-nitzschia (Peragallo) and domoic acid in Scottish shellfish

The diatom genus Pseudo-nitzschia (Peragallo) associated with the production of domoic acid (DA), the toxin reposnsible for amnesic shellfish poisoning, is abundant in Scottish waters. A two year study examined the relationship between Pseudo-nitzschia cells in the water column and DA concentration in blue mussels (Mytilus edulis) at two sites, and king scallops (Pecten maximus) at one site. The rate of DA uptake and depuration differed greatly between the two species with M. edulis whole tissue accumulating and depurating 7 μg g⁻¹ (now expressed as mg kg⁻¹) per week. In contrast, it took 12 weeks for DA to depurate from P. maximus gonad tissue from a concentration of 68 μg g⁻¹ (now mg kg⁻¹) to <20 μg g⁻¹ (now mg kg^‐1). The DA depuration rate from P. maximus whole tissue was <5% per week during both years of the study. Correlations between the Pseudo-nitzschia cell densities and toxin concentrations were weak to moderate for M. edulis and weak for P. maximus. Seasonal diversity on a species level was observed within the Pseudo-nitzschia genus at both sites with more DA toxicity associated with summer/autumn Pseudo-nitzschia blooms when P. australis was observed in phytoplankton samples. This study reveals the marked difference in DA uptake and depuration in two shellfish species of commercial importance in Scotland. The use of these shellfish species to act as a proxy for DA in the environment still requires investigation.     

Dynamic response of woody vegetation on fencing protection in semi-arid areas; Case study: Pilot exclosure on the Firmihin Plateau,Socotra Island

Woody vegetation dynamics and Dracaena cinnabari regeneration have been studied for five years in the conditions of Socotra Island. Woody plants were measured regularly inside and outside the exclosure area, and the growth and survival of D. cinnabari seedlings were observed. In the exclosure of about 1000 m² a total of 49 species were identified, including 23 endemics, growing in the average density of 3.82 specimens per m². The fenced area was overgrown relatively rapidly by dense grass cover – reaching approx. 2.7 t/ha. Species growth dynamics inside and outside the exclosure shows that grazing had a marked impact, leading to the elimination of trees and shrubs. All grazed species grew noticeably in the exclosure, in the average of 50 cm in 5 years. D. cinnabari as the dominant flagship species of Socotra has been studied with regards to regeneration dynamics. Observations indicate that probability of its seedlings survival increases with their age. No seedlings germinated from the seeds sown in the experiment, however, outplanted seedlings performed relatively well. Field observations show that D. cinnabari seed germination is triggered when the seed reaches a protected micro-habitat with a developed humus layer and high relative humidity in the soil lasts for at least two days.