Modeling landscape condition for biodiversity assessment—Application in temperate North America

Conservation decisions are well supported by predictive spatial models that indicate the relative ecological condition of a given place. The intent of this 90 m pixel landscape condition model is to use nationally available spatial data from the USA, Mexico, and Canada to express assumptions regarding the relative ecological effects of land uses on terrestrial natural communities and species. This approach emphasizes and updateable and transparent design which takes advantage of empirical biodiversity data from the USA to both calibrate and validate the model. Map layers depicting infrastructure, land use, and modified vegetation were each scored for site impact and distance decay, and then combined into one map surface. Field observations from Natural Heritage Programs, each scored for relative ecological condition (in categories A = excellent to D = poor), were used to calibrate distance decay parameters. Some 90,000 observations for at-risk species, invasive plant species, and natural communities were used for model validation. Statistically significant distinctions in ecological condition among validation samples were predicted by the resultant spatial model. Variation in landscape condition was then summarized by regional U.S. Landscape Conservation Cooperatives (LCCs) in terms of areas approximating A–D condition. Montane and desert LCCs scored on average much higher in area approximating “A” and “B” landscape condition, while LCCs with more substantial agricultural and urban footprints scored overwhelmingly within the “D” range of condition. Similar analyses illustrated range-wide scoring of landscape condition for major vegetation types across temperate North America.     

Soundness of in situ lipid biomarker analysis: Early effect of heavy metals on leaf fatty acid composition of Lactuca serriola

In previous studies we proposed the plant leaf fatty acid composition, and more precisely the ratio C18:3/(C18:0 + C18:1 + C18:2) as a tool to diagnose soil contamination ex situ. These studies led us to normalize this parameter as a biomarker of soil quality using Lactuca sativa growing under controlled conditions as the plant model species. The evaluation of the toxic effects of pollutants is more difficult to grasp in a real and more complex environment. Hence we developed a study to test the hypothesis that plant leaf fatty acid composition could be used also as a reliable tool to diagnose soil contamination in situ. We tested whether Lactuca serriola (prickly lettuce) could be used as a plant model species for such studies, primarily because it is widely distributed in various European countries and recorded at different habitats, and regarded as an ancestor of the cultivated lettuce L. sativa that was used for ex situ experiments. The results show that the lipid biomarker values were significantly lower in leaves of L. serriola grown on a metallurgic landfill soil than in leaves of plants harvested on surrounding countryside areas. To determine whether the value of the lipid biomarker in L. serriola leaves could be correlated to the soil metal content, we also measured the metal content of the soil corresponding to the rhyzospheric areas from where the prickly lettuce leaves were harvested. The results of the Principal Component Analysis (PCA) show that the lipid biomarker is negatively correlated with both Ni and Cr content. Moreover, these results show that the lipid biomarker values measured in situ were repeatable from year to year, confirm that this biomarker measured in situ would provide an early indication of a plant's exposure to metal, and could be therefore used to facilitate or strengthen the diagnosis of soil contamination.     

Evolution mechanism of non-hydraulic root-to-shoot signal during the anti-drought genetic breeding of spring wheat

The objectives of this study were to: (1) characterize the evolutional tendency of the non-hydraulic root-sourced signal (NRS) from wheat wild relatives to its modern hexaploid species, and (2) test whether species sensitivity to the NRS was allied with their drought tolerance profiles. The NRS was judged to begin when there was a significant lowering of stomatal conductance without change in leaf relative water content (RWC). The lethal soil water content (LSWC) was operationally characterized as the soil water content (SWC) at the drying lethal point of wheat plants. The threshold of soil water content (TSWC) at which the NRS was triggered, and the LSWC differed amongst six wheat species. For “MO1” and “MO4” representing ‘diploid’ species, the TSWC and the LSWC were initiated successively at about 51% FWC (field water capacity) and about 30% FWC, respectively. Conversely, “Plateau 602” and “Longchun 8139-2” (modern hexaploid species) exhibited the TSWC and the LSWC between about 68% FWC and less than 14% FWC, a much wider threshold range (TR). Increasing TSWC was significantly correlated with decreasing LSWC (r = 0.9464^**). The widened TR from the TSWC to the LSWC was also significantly correlated with longer survival days (SD) and higher maintenance ratio of grain yield (MRGY), respectively (r = 0.9411^** and 0.8068^*, respectively). Meanwhile, those species having higher TSWC had the least reduction ratio of stomatal conductance under the decreasing soil moisture from −0.2 to −1 MPa. This suggests that advances in yield performance and drought tolerance would be made evolutionally by targeted selection for an earlier onset of NRS.     

The inorganic component of green roof substrates impacts the growth of Mediterranean plant species as well as the C and N sequestration potential

Extensive green roofs substrates should meet a list of physicochemical and biochemical requirements to be used as a basis for plant growth: high water holding capacity, good aeration, low bulk density, and proper drainage are some of them. In recent years, the impact of different organic matter doses and the substrate depth on the subsequent plant growth have been deeply studied. By contrast, there are not many publications about the effect of the inorganic component of these substrates on plant development and C and N sequestration potential by the green roof system, and even more under semi-arid Mediterranean conditions. Four substrates were made by mixing the same compost, at 10% by volume, with different inorganic materials: CsB (compost, silica sand, and crushed bricks; 1:1:8), CB (compost and crushed bricks; 1:9), CSB (compost, clay-loam soil, and crushed bricks; 1:1:8), and CsS (compost, silica sand, and clay-loam soil; 1:1:8). These were placed, a depth of 10 cm, on “cultivation tables” in an experimental farm located in the SE of Spain. Two native species were sown in each substrate: Lotus creticus and Asteriscus maritimus. Physicochemical, nutritional, and biochemical properties of the substrates as well as the plant development were evaluated during a 10-month experiment. The CsB and CSB mixtures had good physicochemical properties (high porosity and acceptable water holding capacity) although the levels of C, N, and humic substances were higher in the soil-containing substrates than in the CB and CsB mixtures. The hydrolytic enzyme activity was also promoted in these mixtures. The plant growth pattern showed differences regarding the inorganic composition of the substrate; L. creticus had superior development in the CsB substrate and A. maritimus was able to grow in all tested substrate mixtures, although its cover was low, being a more versatile candidate to establish a green roof cover. The greatest C and N sequestration potential was achieved by the CsS mixture, reaching 1.06 kg TC m⁻² of green roof substrate. Therefore, substrate composition impacts the growth of native plant species as well as the C and N sequestration by the green roof system.     

Capacities of soil water reservoirs and their better regression models by combining “merged groups PCA” in Chongqing,China

Soil water resource, together with the surface and sub-surface water resource, is essential to the regional water balance and world water cycle. A total of 90 soil samples were collected from 30 different soil profiles of dry fields throughout Chongqing, China randomly to show how soil could be a crucial part of water resources by discussing their five types of calculated soil water reservoir capacities, namely the total soil water reservoir capacity (mm) (TC), soil water storage capacity (mm) (SC), unavailable soil water reservoir capacity (mm) (UC), available soil water reservoir capacity (mm) (AC), and soil dead water storage capacity (mm) (DC) in certain layer, respectively. Overall, the total soil water reservoir capacity in 0–40 cm was about 209 mm, of which 70 mm belonged to available soil water reservoir capacity. Not all the five types of soil water reservoir capacities had significant correlations between each other. Soil structure, especially the size and quantity of soil pore was mainly determined by soil particle composition (clay, silt, and sand content). The more sand and less clay led to the more soil macropores, which provided room for soil water. Thus, clay, silt, and sand content jointly produced profound influence on soil water reservoir capacities. Nevertheless, specific water capacity and topographic factors displayed weak correlations to soil water reservoir capacities, which required further research works. Ultimately, the better regression models were achieved by multiple regression analysis coupled with “merged groups PCA” than by multiple regression analysis with “all variables PCA”. UC, SC, TC and DC could be well simulated (mostly R² > 0.70; P < 0.05) through normal multiple regression analysis using original variables as well as multiple regression analysis with “merged groups PCA”. Only regression models of TC and DC were highly significant (mostly R² > 0.70; P < 0.05) through “all variables PCA” method. And there were poor coefficients of determination (R²) for AC (mostly R² < 0.40; P < 0.05) by all the three regression methods.     

Results of the implementation of the System for the Integrated Assessment of Protected Areas (SIAPA) to the protected areas of the Autonomous Region of Madrid (Spain)

The long-term conservation of biodiversity and related ecosystems goods and services of the Autonomous Region of Madrid is jeopardized by the intensive resource-consuming development model followed by the region in the past few decades. This paper presents the aggregated results of the first integrated assessment of the protected areas of the Autonomous Region of Madrid (Spain) with the System for the Integrated Assessment of Protected Areas (SIAPA). Detailed results are also provided for individual protected areas as supplementary data. The assessment was done during 2009–2010, on ten protected areas differing in their sizes (from 2.5 to 52,796 ha), protection categories (seven categories) and types of ecosystems present. Comparison of results from both assessment models of the SIAPA (the Complete Model and the Simplified Model) is also presented. The results from the Complete Model show that eight out of the ten protected areas of the Autonomous Region of Madrid are currently ineffective. The poorest partial indexes overall were: “State of Conservation” and “Social and Economic Context”. The only indexes significantly correlated with the effectiveness of a protected area were: the “State of Conservation” (r = 0.851**) and the “Social Perception and Valuation” (r = 0.786**). Although not as relevant as was thought, “Management” and the other non-significant factors are likely to influence the effectiveness of protected areas as well. The results for the Simplified Model are slightly better than those for the Complete Model, although this is probably a specific result of this assessment. The two models of the SIAPA were very significantly correlated, although their aggregated results should not be compared directly.     

Biological treatment of n-hexane and methanol in trickle bed air biofilters under acidic conditions

This study focuses on evaluating the degradation of n-hexane/methanol mixture in trickle-bed-air-biofilters (TBABs). Two different concentration ratios of methanol:n-hexane were evaluated (3:1) for TBAB “A” and (5:1) for TBAB “B”. Both TBABs were run and fed with nutrients buffered at pH 4 for encouraging the growth of fungi. The TBABs were loaded with pelletized diatomaceous earth support media and were run at an empty bed residence time of 120 s. n-Hexane loading rates (LRs) ranged from 0.9 to 13.2 g/m³ h for both TBABs. The corresponding methanol LRs varied from 2.3 to 37.7 g/m³ h and from 4.6 to 64.5 g/m³ h for TBABs “A” and “B”, respectively. Experimental results have shown that the degradation of n-hexane in presence of methanol is enhanced for n-hexane LRs less than 10.6 g/m³ h as compared to previous study for sole-fed n-hexane, but for n-hexane LRs of 13.2 g/m³ h, the performance of TBABs in eliminating n-hexane depended on the methanol to n-hexane ratios. The impact was less severe for TBAB “A” (RE 85%) as compared to TBAB “B” (RE 72%). This is attributed to the high LRs of methanol in TBAB “B”. n-Hexane performance stability was another advantage attained.     

Impacts of monosodium glutamate industrial wastewater on plant growth and soil characteristics

Research into utilization of monosodium glutamate industrial wastewater (MSGW) as a plant nutrient source was undertaken. The physico-chemical and microbiological characteristics of MSGW were analyzed in detail. Effect of MSGW on early growth of Chinese cabbage (Brassica rapa L. cv. Pekinensis) and maize (Zea mays L. cv. Bright Jean) was tested by the seed germination bioassay. Subsequently, in a greenhouse pot experiment using the same plant species, effects of MSGW application rates on the plant biomass yield, nitrogen content and soil properties were analyzed. The MSGW was characterized by high levels of N (56.7 g l^?1), organic C (344.6 g l^?1), total solids (600 g l^?1) and other minerals. At MSGW concentrations below 1%, germination indices for both the plant species were significantly (p < 0.01) higher than the control. Further, the greenhouse study results indicated significant increase in the plant biomass yield at MSGW application rates of 5000 and 7500 l ha^?1. As the MSGW dose increased, the biomass yield decreased, decreasing the N-use efficiency. Maize showed significantly higher wastewater N-use efficiency compared to the Chinese cabbage. Although the total culturable bacterial and fungal counts in the raw MSGW were low, addition of MSGW to the soil increased the soil microbial activities and soil respiration. Soil organic C was also increased by the addition of MSGW, due to the presence of significant amounts of organic C in the wastewater. This preliminary study demonstrates that by proper management of the pH and optimization of application rate, MSGW can be utilized as a nutrient source for plant growth. Further long-term field studies to evaluate the environmental impact of MSGW usage in agriculture are being designed to reduce the environmental risks associated with the reuse of this underutilized wastewater in the agriculture.     

Promoting effect of Fusarium oxysporum [f.sp. strigae] on abundance of nitrifying prokaryotes in a maize rhizosphere across soil types

The integrated application of resistant crop varieties with biological control agents (BCAs) such as the Fusarium oxysporum [f.sp. strigae] strain “Foxy-2” has shown to be effective in fighting off the weed Striga hermonthica which is parasitic to several cereals cultivated in Sub-Saharan Africa (Schaub et al., 2006; Venne et al., 2009). “Foxy-2” proliferates in the rhizosphere and has been mainly studied for its virulence and mode of action. Contrary, no understanding is available regarding its interactions with key rhizosphere microorganisms steering relevant nutrient cycles in soils including nitrogen (N). In this study, we tested the hypothesis that “Foxy-2” displaces indigenous prokaryotic, N cycling communities in the maize rhizosphere due to competition for organic resources. Consequently, we evaluated if the application of an N-rich organic residue (i.e., Tithonia diversifolia with C/N ratio = 13, lignin content = 8.9%, polyphenol content = 1.7%) compensates these presumed competition effects. In a rhizobox experiment, quantitative polymerase chain reaction was used to follow the response of rhizosphere ammonia-oxidizing archaea (AOA) and bacteria (AOB) as well as total bacteria and archaea following “Foxy-2” inoculation in two physico-chemically contrasting soils (sandy Ferric Alisol versus clayey Humic Nitisol). Soils were treated with or without “Foxy-2”, S. hermonthica seeds, and T. diversifolia residues. Contrary to our expectations, we observed a distinct soil texture dependent, promoting effect of “Foxy-2” on rhizosphere prokaryotes. Abundance of AOA and total prokaryotic communities increased in response to “Foxy-2” in the sandy soil, while AOB remained unaffected. This effect on AOA was accelerated when T. diversifolia residues were incorporated. Further, in the clayey soil, AOA abundance was promoted when exposed to S. hermonthica infestation of maize. This suggested their capability to adapt to this biotic stress situation. It was concluded that “Foxy-2” did not pose a negative effect on targeted indigenous microorganisms, but the underlying mechanisms for the observed promoting effect of AOA abundance by “Foxy-2” inoculation are yet to be understood.     

Agri-environment incentive payments and plant species richness under different management intensities in mountain meadows of Switzerland

We investigated whether agri-environmental incentive payments help to maintain biodiversity. We studied the effect of agricultural management intensity on vascular plant species richness and plant assemblages of mountain meadows in Switzerland. Other factors such as slope, altitude or accessibility (distance from farmyard) were also taken into account. Vegetation sampling was conducted at 69 sites representing five different management types, differing with respect to nutrient input and soil moisture: (i) dry extensive meadows; (ii) extensive meadows; (iii) dry low-intensive meadows; (iv) low-intensive meadows; (v) intensive meadows. There was a significant negative relationship between plant species richness and management intensity: The mean number of plant species per management type declined markedly when management intensity increased, although dry sites harboured slightly more species regardless of management intensity (dry extensive > dry low intensive > extensive > low intensive >> intensive meadows). Species richness was clearly affected by management intensity, but not so by slope, altitude or accessibility. There was a gradual shift in plant assemblages among management types with only intensive meadows differing from the other four types of differently managed meadows. We therefore found, in contrast to many studies done in the European lowlands, positive effects of incentive payments on plant species richness.     

An avifaunal survey of mesic manmade ecosystems “Oases” in algerian hot-hyperarid lands

Man made ecosystems of dry lands are key habitats due to their ecological characteristics to survey biodiversity. This study investigated bird diversity in three oases of the Northern Algerian Sahara (i.e., Biskra in 2006, Oued Souf in 2008 and Ouargla in 2009), by using the spot-mapping method. Bird density “D” (pairs/10 ha), species richness “S” (number species), diversity (Shannon index) “H′” (in bits), and evenness “E” varied from one oasis to another (Biskra: D = 98.5, S = 47, H′ = 4.49, E = 0.81; Oued Souf: D = 96, S = 33, H′ = 3.9, E = 0.77; Ouargla: D = 91.5, S = 44, H′ = 4.39, E = 0.80). Differences in bird diversity between the monitored palm groves are due to the ecological characteristics of each environment. Documented literature outlined close taxonomic similarities between bird assemblages of the study area with many Northern Saharan oases. The Hybrid Sparrow Passer domesticus x Passer. hispaniolensis and some Columbidae species including Columba livia, Streptopelia turtur, Streptopelia senegalensis, and Streptopelia decaocto were the abundant species throughout surveyed oases in which they represented more than half (55.6%) of the sum of species densities (D = 286 pairs/10 ha). These synthropic species have known a huge expansion of their distribution range throughout Algerian oases. The correspondence analysis allowed the aggregation of both families and species into oasis they belong to. One-way ANOVA was tested to analyse variations of both family and species densities between studied oases. The ANOVA revealed there was no significant variation either in family densities (p = 0.937) or in bird densities (p = 0.622) between the surveyed oases because of the small size of bird populations.     

Unusual change in activity pattern at cool temperature in a reptile (Sphenodon punctatus)

Animals that can be active both during day and night offer unique opportunities to identify factors that influence activity pattern. By experimental manipulations of temperatures under constant photoperiod, we aimed to determine if emergence, activity and thermoregulatory behaviour of juvenile tuatara (Sphenodon punctatus) varied at different temperatures (20 °C, 12 °C and 5 °C). To help clarify its activity pattern, we compared tuatara with two lizard species endemic of the South Island of New Zealand for which activity pattern is known and clearly defined: the nocturnal common gecko Woodworthia “Otago/Southland” and the diurnal McCann׳s skink Oligosoma maccanni. Tuatara showed similar responses to both species of lizards. Similar to the diurnal skinks, tuatara emerged quickly at 20 °C and 12 °C while nocturnal geckos took more time to emerge. Like nocturnal geckos, tuatara continued to be active at 5 °C, but only during the day. Interestingly, tuatara shifted from diurno-nocturnal activity at 20 °C and 12 °C to being strictly diurnal at 5 °C. We suggest that this temperature-dependent strategy maximises their survival during cold periods.     

Injury due to extravasation of thiopental and propofol: Risks/effects of local cooling/warming in rats

Inadvertent leakage of medications with vesicant properties can cause severe necrosis in tissue, which can have devastating long-term consequences. The aim of this study was to evaluate the extent of extravasation injury induced by thiopental and propofol, and the effects of cooling or warming of local tissue on extravasation injury at macroscopic and histopathologic levels. Rats were administered intradermally thiopental (2.5 mg/100 µL) or propofol (1.0 mg/100 µL). Rats were assigned randomly to three groups: control (no treatment), cooling and warming. Local cooling (18–20 °C) or warming (40–42 °C) was applied for 3 h immediately after agent injection. Lesion sizes (erythema, induration, ulceration, necrosis) were monitored after agent injection. Histopathology was evaluated in skin biopsies taken 24 h after agent injection. Thiopental injection induced severe skin injury with necrosis. Peak lesions developed within 24 h and healed gradually 18–27 days after extravasation. Propofol induced inflammation but no ulceration, and lesions healed within 1–2 days. Local cooling reduced thiopental- and propofol-induced extravasation injuries but warming strongly exacerbated the skin lesions (e.g., degeneration, necrosis) induced by extravasation of thiopental and propofol. Thiopental can be classified as a “vesicant” that causes tissue necrosis and propofol can be classified as an “irritant”. Local cooling protects (at least in part) against skin disorders induced by thiopental and propofol, whereas warming is harmful.     

Field-to-laboratory transport protocol impacts subsequent physiological biomarker response in the marine mussel,Perna canaliculus

The transfer of mussels from field to laboratory, or transplantation between clean and contaminated field settings, is a common protocol in ecotoxicology. However, collection and transport of mussels could lead to stress that may impact biomarker responses, and thus confound interpretation of results. Physiological responses (clearance rate, absorption efficiency, excretion rate, respiration rate and scope-for-growth) of green-lipped mussels (Perna canaliculus) exposed to four different transportation protocols were investigated. These protocols included immersion in site seawater (SSW), immersion in artificial seawater (ASW), and emersion (aerial transport; EMS) at two temperatures (15 °C and 5 °C). Physiological measurements were conducted after a simulated 24 h “transport” phase and a 48 h “recovery” phase. Clearance rates were significantly inhibited by the EMS 5 °C and ASW protocols relative to SSW treatment, although the clearance rate of the latter recovered after 48 h. A similar pattern was observed for excretion and respiration rates for ASW. Decreased excretion rates for EMS 15 °C and respiration rates for EMS 5 °C were also recorded relative to values for SSW following “recovery”. Negative scope-for-growth was observed for all treatments except EMS 15 °C. These data suggest transport emersed at ambient air temperatures is the best method to maintain physiological health of green-lipped mussels.     

Ecological gradients and environmental impact in the forest dwelling Haplothrips subtilissimus (Thysanoptera: Phlaeothripidae) phenotypic variability

Classification of phenotypic variability in forest dwelling arthropods, especially in applied bioindication, remains difficult due to the complex and synergic ecological interactions. Ecologically, it corresponds with the concept of alternative ontogenies in order to maintain high population fitness. The research on the geobiont Haplothrips subtilissimus (Thysanoptera: Phlaeothripidae) morphometric plasticity alongside selected ecological gradients (temperature, humidity, food availability) and the environmental impact in the xerothermous hilly oak wood (Martinský les, SW Slovakia), have revealed that (MAN(C)OVA and Kruskal–Wallis test) the head width (p < 0.001) and anterior pronotum width (p ≤ 0.002) as the only statistically significant variables. The Kruskal–Wallis test (non parametric ANOVA) revealed significant variation (more noticeable in males) in ecologically more diverse ecotone stands. A significant correlation (p < 0.001) could be shown between the morphometric parameter pairs “head width” and “anterior pronotum width” for both sexes (0.729 for females and 0.822 for males) and between anterior and posterior pronotum width only for males (0.859). Pillai's statistics revealed an interaction of soil humidity and soil temperature which confirms female body parameters depend on habitat conditions (p = 0.011). Females responded mainly to soil temperature (p = 0.018) and food availability (p = 0.030). Soil humidity interacts with the male's morphology (soil humidity p = 0.040), while the relationship to food availability (Acarina) was not statistically significant (p = 0.350). No body parameter has been significantly affected by environmental stress.     

Macrophytes in the anthropic constructions of the Venice littorals and their ecological assessment by an integration of the “CARLIT” index

A check-list of the macroalgae which colonize the artificial structures “dykes” formed by limestone blocks, placed between the northern Adriatic Sea and the Venice Lagoon to protect the wide sea inlets of Lido and Malamocco, the stone breakwaters and the submerged reefs parallel and perpendicular to the sea coastline of the Lido island “Murazzi” is presented. Macroalgae have been sampled monthly during one-year period (February 2007–January 2008) both in the lagoon inlets and along the marine coast. Flora was represented by 213 taxa: 61 Chlorophyta, 114 Rhodophyta, 38 Ochrophyta (37 Phaeophyceae, 1 Xanthophyceae), with the richest and luxuriant vegetation in the lagoon inlet areas. The application of the Rhodophyta/Chlorophyta (R/C) index and the Expert-Macrophyte Quality Index (E-MaQI) highlighted the “High” ecological status (EQR > 0.9) of the lagoon inlet areas.As E-MaQI is not applicable in marine areas, an adaptation of CARLIT to the anthropic structures of the north-western coasts of the northern Adriatic Sea and its integration with the dominant taxa is proposed.The application of the revised index to the Lido dykes and breakwaters placed along the marine littorals shows “Moderate” conditions.     

Convergence in plant traits between species within grassland communities simplifies their monitoring

Plant trait measurement is a very powerful and promising method for assessing the effects of land use change on ecosystem behavior in grasslands, but it is very time-consuming. Hence we pose the following questions for simplifying diagnosis and monitoring: (i) are plant traits (PTs) similar between plant life forms (PLF: grasses, rosettes, upright forbs, legumes) within a plant community? (ii) is it possible to define the main plant community characteristics by measuring traits on one PLF or a limited number of dominant species?Six PTs known for their ability to characterize the capacity of species to exploit resource-rich or -poor environments and for their competitive dominance in response to disturbance (specific leaf area (SLA), leaf dry matter content (LDMC), plant height (H), C and N contents, flowering time) were measured on the species of 18 plant communities located in Central Pyrenees. The experiment combined 2 fertility levels and 3 defoliation regimes (cutting, grazing). Comparisons were made between the weighted values at community, PLF and two dominant species levels. Regression analysis shows that there were significant correlations between grasses and rosettes for 4 PTs. For H, N and C:N ratio, data for both grass and rosette PLFs were close to the bisecting line. The largest difference in the intercept was observed for LDMC. On the basis of plant traits weighted for all the species, plant communities were ranked in similar ways for SLA and H (Spearman r > 0.93; p < 0.001) and to a lesser extent for LDMC (r = 0.72; p < 0.001). Convergence in weighted plant traits for different PLFs within a plant community mean that in the studied grasslands, defoliation regime and nutrient availability act as strong filters that impose, at least at PLF level, very similar PFTs. This determines a specific local community structure and composition. An application of this result in managed grasslands is the possibility of focusing on one PLF or a limited number of species for vegetation diagnosis and monitoring.     

Rhizobium indicum sp. nov., isolated from root nodules of pea (Pisum sativum) cultivated in the Indian trans-Himalayas

Three strains of rhizobia isolated from effective root nodules of pea (Pisum sativum L.) collected from the Indian trans-Himalayas were characterized using 16S rRNA, atpD and recA genes. Phylogeny of the 16S rRNA genes revealed that the newly isolated strains were members of the genus Rhizobium with ≥99.9% sequence similarity to the members within the “Rhizobium leguminosarum” group. Phylogenetic analyses based on the concatenated sequences of atpD and recA gene, and 92 core genes extracted from the genome sequences indicated that strains JKLM 12A2^T and JKLM 13E are grouped as a separate clade closely related to R. laguerreae FB206^T. In contrast, the strain JKLM 19E was placed with “R. hidalgonense” FH14^T. Whole-genome average nucleotide identity (ANI) values were 97.6% within strains JKLM 12A2^T and JKLM 13E, and less than 94% with closely related species. The digital DNA-DNA hybridization (dDDH) values were 81.45 within the two strains and less than 54.8% to closely related species. The major cellular fatty acids were C_18:1w7c in summed feature 8, C_{14:0 3OH}/C_{16:1 iso I} in summed feature 2, and C_18:0. The DNA G + C content of JKLM 12A2^T and JKLM 13E was 60.8 mol%. The data on genomic, chemotaxonomic, and phenotypic characteristics indicates that the strains JKLM 12A2^T and JKLM 13E represent a novel species, Rhizobium indicum sp. nov. The type strain is JKLM 12A2^T (= MCC 3961^T = KACC 21380^T = JCM 33658^T). However, the strain JKLM 19E represents a member of “R. hidalgonense” and the symbiovar viciae.     

Effects of rest grazing on organic carbon storage in Stipa Baicalensis steppe in Inner Mongolia

In order to evaluate the potential effects of rest grazing on organic carbon storage on the Stipa baicalensis steppe in Inner Mongolia, compared the S. baicalensis steppes after rest grazing for 3 years, 6 years, and 9 years, using potassium dichromate heating method, this study analyzed the organic carbon storage of plant and soil in the steppes among different periods of rest grazing. The results indicated that as the rest grazing years prolonged, the biomass included above-ground parts, litters and underground plant parts(roots) of the plant communities all increased, meanwhile the carbon content of the biomass increased with the rest grazing years prolonged. For the zero rest grazing (RG0) steppe and the steppes after a rest grazing of 3 years (RG3a), 6 years (RG6a), 9 years (RG9a), the carbon storage in above-ground parts of plant communities were 42.60 g C/m², 66.33 g C/m², 83.46 g C/m², 100.29 g C/m² respectively; the carbon storage of litters were 7.85 g C/m², 9.12 g C/m², 9.18 g C/m², 11.54 g C/m² separately; the carbon storage of underground plant parts (0–100 cm) were 281.40 g C/m², 576.38 g C/m², 745.33 g C/m², 1279.61 g C/m² respectively; and the carbon storage in 0–100 cm soil were 22991.14 g C/m², 24687.75 g C/m², 26564.86 g C/m²,33041.55 g C/m². The results suggested that as the rest grazing years prolonged, the organic carbon storage in plant communities and soil increased. The carbon storage of underground plant parts and soil organic carbon mainly concentrated in 0–40 cm soil. After rest grazing for 3 years, 6 years, and 9 years, the increased soil organic carbon were as the 81.14%, 85.84%, and 89.46% of the total increased carbon; From the perspective of carbon sequestration cost, the total cost of RG3a, RG6a and RG9a were 2903.40 RMB/hm², 5806.80 RMB/hm², and 8710.20 RMB/hm². The cost reduced with the extension of rest grazing years, 0.17 RMB/kg C, 0.16 RMB/kg C, 0.09 RMB/kg C for RG3a, RG6a and RG9a respectively. From the growth characteristics of grassland plants, the spring was one of the two avoid grazing periods, timely rest grazing could effectively restore and update grassland vegetation, and was beneficial to the sustainable use of grassland. From the available data, the organic carbon storage of RG9a was the highest, while the cost of carbon sequestration was the lowest. Therefore, spring rest grazing should be encouraged to continue for it was proved to be a very efficient grassland use measures.     

Response of native grasses and Cicer arietinum to soil polluted with mining wastes: Implications for the management of land adjacent to mine sites

Mine tailings are an environmental problem in Southern Spain because wind and water erosion of bare surfaces results in the dispersal of toxic metals over nearby urban or agricultural areas. Revegetation with tolerant native species may reduce this risk. We grew two grasses, Lygeum spartum and Piptatherum miliaceum, and the crop species Cicer arietinum (chickpea) under controlled conditions in pots containing a mine tailings mixed into non-polluted soil to give treatments of 0%, 25%, 50%, 75% and 100% mine tailings. We tested a neutral (pH 7.4) mine tailings which contained high concentrations of Cd, Cu, Pb and Zn. Water-extractable metal concentrations increased in proportion to the amount of tailings added. The biomass of the two grasses decreased in proportion to the rate of neutral mine-tailing addition, while the biomass of C. arietinum only decreased in relation to the control treatment. Neutron radiography revealed that root development of C. arietinum was perturbed in soil amended with the neutral tailings compared to those of the control treatment, despite a lack of toxicity symptoms in the shoots. In all treatments and for all metals, the plants accumulated higher concentrations in the roots than in shoots. The highest concentrations occurred in the roots of P. miliaceum (2500 mg kg^?1 Pb, 146 mg kg^?1 Cd, 185 mg kg^?1 Cu, 2700 mg kg^?1 Zn). C. arietinum seeds had normal concentrations of Zn (70–90 mg kg^?1) and Cu (6–9 mg kg^?1). However, the Cd concentration in this species was ～1 mg kg^?1 in the seeds and 14.5 mg kg^?1 in shoots. Consumption of these plant species by cattle and wild fauna may present a risk of toxic metals entering the food chain.