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The importance of conservation and ecological restoration of the rare and economically important tree Phoebe zhennan is increasingly recognized. To this purpose, phosphorus (P) addition has been proposed to improve soil biological attributes and face the anticipated drought under climate change, though few studies have investigated its effect on the interaction between the soil microorganisms and plant host, as well as on ecosystem productivity. We investigated the effect of P addition on soil chemical properties, microbial communities, and enzyme activities in a soil planted with P. zhennan under two levels of water treatments (optimum water and drought treatments). P additions had no significant effect on microbial communities, dissolved organic nitrogen (DON), pH and soil moisture (SM), though the available P (aP) increased. Compared with no P treatment, alkaline phosphate and β-fructofuranosidase activities increased with P additions in the drought treatment. Drought decreased the total phospholipid-derived fatty acids (PLFAs), arbuscular mycorrhiza fungi (AMF), and fungi PLFAs compared to the well-watered. These findings indicated that P additions does not ameliorate the impact of drought on soil microbial communities and enzyme activities, except alkaline phosphate and β-fructofuranosidase, and P may not be responsible for regulating biochemical processes essential for maintaining the fertility of soil planted with P. zhennan under drought conditions. It is hypothesized that the lack of effects of P addition on the majority of the microbial properties could be due to the soil mechanism employed by P. zhennan to tolerate harsh conditions.

Environmental variables such as soil moisture and phosphorus (P) might influence above- and below-ground biodiversity. In this study, we investigated the rarely reported individual and interactive multifactor effects of soil moisture and phosphorus addition with the type of above-ground tree species (biological interactions) on the soil nematode community structure. We established a completely randomized experimental design with two plant types (N2-fixer and non-nitrogen fixer) and different combinations of water treatments and P additions (i.e., water with P addition, water only, drought with P addition, and drought only) in a greenhouse and investigated their effects on the soil chemical properties and nematode community. Soil samples were collected at the end of the experiment and were analyzed for soil moisture content (SM), available phosphorus (aP), nitrate nitrogen (NO3−–N), ammonium nitrogen (NH4+–N), dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and nematode community. The following trophic groups were assigned to the nematodes: bacterivores (Ba), fungivores (Fu), omnivores–predators (Op), and plant parasites (PP). The channel index (CI), enrichment index (EI), maturity index (MI), genus richness (GR), and Simpson dominance (Ig) were adopted to indicate the indices of the nematode food web. Phosphorus addition and its interaction with water treatments had no statistically significant effects on the soil nematode community, but there were significant decreasing (p

A current challenge for ecological research in agriculture is to identify ways in which to improve the resilience of the soil food web to extreme climate events, such as severe rainfall. Plant species composition influence soil biota communities differently, which might affect the recovery of soil food web after extreme rainfall. We compared the effects of rainfall stress up on the soil microbial food web in three planting systems: a monoculture of the focal species Zanthoxylum bungeanum and mixed cultures of Z. bungeanum and Medicago sativa or Z. bungeanum and Glycine max. We tested the effect of the presence of a legume on the recovery of trophic interactions between microorganisms and nematodes after extreme rainfall. Our results indicated that all chemical properties of the soil recovered to control levels (normal rainfall) in the three planting systems 45 days after exposure to extreme rain. However, on day 45, the bulk microbial community differed from controls in the monoculture treatment, but not in the two mixed planting treatments. The nematode community did not fully recover in the monoculture or Z. bungeanum and M. sativa treatments, while nematode populations in the combined Z. bungeanum and G. max treatment were indistinguishable from controls. G. max performed better than M. sativa in terms of increasing the resilience of microbial and nematode communities to extreme rainfall. Soil microbial biomass and nematode density were positively correlated with the available carbon and nitrogen content in soil, demonstrating a link between soil health and biological properties. This study demonstrated that certain leguminous plants can stabilize the soil food web via interactions with soil biota communities after extreme rainfall.

Extreme precipitation as global change greatly affects above- and below-ground biodiversity. Soil macrofauna play a key role in the agroforestry ecosystem processes. Extreme precipitation might negatively impact soil macrofauna by changing soil water content. Particularly, whether cropping types are beneficial to alleviate response of soil macrofauna to extreme precipitation remains unexplored. Effects of simulated extreme precipitation of 1 month on soil macrofauna were studied under Chinese prickly ash (Zanthoxylum bungeanum) intercropped with soybean (Glycine max), Chinese prickly ash intercropped with sweet pepper (Capsicum annuum), and Chinese prickly ash monoculture. Soil macrofauna and soil samples were collected in three soil depths (0–10, 10–20, and 20–30 cm) per plot. The abundance, diversity, and vertical distribution of soil macrofauna were analyzed for each sample at genus and trophic level. Each sieved soil sample was analyzed for soil water content, soil nitrate nitrogen (NO3−–N), ammonium nitrogen (NH4+–N) and organic matter. Descriptive statistics and significance tests on raw data were carried out using the SPSS 16.0 software at P

Nematodes play a significant role in soil biogeochemical cycling. However, our understanding of their community carbon budget response for a shift in the environmental conditions of natural and planted forests is limited. Therefore, we investigated the nematode community composition, daily carbon used in production and daily carbon budget, environmental variables, and the interaction among trophic groups in the moss, litter and 0–5 cm soil layers of natural subalpine spruce forest and plantations in western Sichuan, China. The result revealed that plantations increased the total nematode daily carbon budget by approximately 52% through the herbivore channel in the 0–5 cm soil layer. The herbivorous nematodes’ daily carbon budget and production in the moss layer of plantations decreased by approximately 60% compared to natural forests. Nematode daily carbon used in production and carbon budget had a strong negative correlation with genus richness. The water content and total carbon was the most important environmental factor that affected the nematode carbon budget and production, respectively. However, the environmental factors indirectly affect the daily carbon budget of herbivore nematodes through omnivore top-down control in subalpine forest ecosystems. Our findings highlight that the planted ecosystems have a certain capacity to maintain abundance, richness, and carbon budget of soil nematode but increase the risk of herbivorous pests.

Background: We aimed to characterise the geographical distribution of Sorensen-based multi-site dissimilarity (beta(sor)) and its underlying true turnover (beta(sim)) and nestedness (beta(sne)) components for Chinese Lauraceae and to analyse their relationships to current climate and past climate change. Methods: We used ensembles of small models (ESMs) to map the current distributions of 353 Lauraceae species in China and calculated beta(sor) and its beta(sim) and beta(sne) components. We tested the relationship between beta(sor), beta s(ne) and beta(sim) with current climate and past climate change related predictors using a series of simultaneous autoregressive (SAR(err)) models. Results: Spatial distribution of beta(sor) of Lauraceae is positively correlated with latitude, showing an inverse relationship to the latitudinal alpha-diversity (species richness) gradient. High beta(sor) occurs at the boundaries of the warm temperate and subtropical zones and at the Qinghai-Tibet Plateau due to high beta(sne). The optimized SAR(err) model explains beta(sor) and beta(sne) well, but not beta(sim). Current mean annual temperature determines beta(sor) and beta(sne) of Lauraceae more than anomalies and velocities of temperature or precipitation since the Last Glacial Maximum. Conclusions: Current low temperatures and high climatic heterogeneity are the main factors explaining the high multi-site beta-diversity of Lauraceae. In contrast to analyses of the beta-diversity of entire species assemblages, studies of single plant families can provide complementary insights into the drivers of beta-diversity of evolutionarily more narrowly defined entities.

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios., This research was supported by a grant from DOB Ecology to T.W.C., a grant from the Netherlands Organization for Scientific Research (grant 016.Veni.181.078) to S.G., grants from NSF (OPP 1115245, 1341736, 0840979) to B.J.A., by a Ramon y Cajal fellow award (RYC-2016-19939) to R.C.H., a grant from UNEP & Global Environment Facility to J.E.C., a grant from NERC (NE/M017036/1) to T.C., a grant from FAPEMIG/FAPESP/VALE S.A.(CRA-RDP-00136-10) to L.B.C., through the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) awarded to S.R.C., a grant from CNPq PROTAX (562346/2010-4) to J.M.d.C.C., a grant from DFG (CRC990) to V.K. and S.S., a grant from the MSHE of Russia (AAAA-A17-117112850234-5) to A.A.K., grants from the Chinese Academy of Sciences (XDB15010402) and the National Natural Science Foundation of China (41877047) to Q.L., grants from the National Natural Science Foundation of China (31330011, 31170484) to W.L., grants from NERC (NE/M017036/1) to M.M., grants from the Spanish Ministry of Innovation (CGL2009-14686-C02-01/ 02, CGL2013-43675-P) to J.A.R.M., grants from NSF (DEB-0450537, DEB-1145440) to P.M., T.O.P. and K. Powers, grants from the German Academic Exchange Service (PKZ 91540366) and NAFOSTED (106.05 – 2017.330) to T.A.D.N., by an ARC Discovery project (DP150104199) to U.N.N., by the National Key Research and Development Program of China (2016YFC0502101) and the National Natural Science Foundation of China (31370632) to K. Pan, a grant from the Natural Environment Research Council (NERC) to D.G.W., a grant from BAPHIQ (106AS-9.5.1-BQ-B3) J.-i.Y. The James Hutton Institute receives financial support from the Scottish Government Rural and Environment Science and Analytical Services (RESAS) division. Investigations in northwest Russia were carried out under state order for IB KarRC RAS and are partially supported by the Russian Foundation for Basic Research (18-34-00849). We thank E. Clark and A. Orgiazzi for review of the manuscript; and R. Bouharroud, Z. Ferji, L. Jackson and E. Mzough for providing data.

Water and nutrients, particularly phosphorus (P), are the two most limiting factors for dwarf bamboo growth in tropical and subtropical areas. Dwarf bamboo is highly sensitive to water stress and often causes severe P deficiency in its growing soils due to the characteristics of shallower roots and expeditious growth. However, little is known about its photoprotective response to soil water deficit and the underlying mechanisms regulated by P application. In this study, a completely randomized design with two factors of two water regimes (well-watered and water-stressed) and two P levels (with and without P application) was arranged to investigate this issue in dwarf bamboo (Fargesia rufa) plants. Water stress not only decreased water status and photochemical activity but also increased lipid peroxidation due to reactive oxygen species (ROS) accumulation irrespective of P application. In this case, thermal dissipation and antioxidative defense were promoted. Moreover, the role of the water−water cycle under this stress still could not be ignored because it accounted for a large proportion of total energy (JPSII). P application significantly enhanced photochemical activity accompanied by increased chlorophyll content in water-stressed plants. Meanwhile, P application remarkably reduced thermal dissipation and hardly affected photorespiration and the water−water cycle under water stress. Although P application only enhanced ascorbate (AsA) level, ROS, particularly hydrogen peroxide (H2O2), and lipid peroxidation were significantly reduced in water-stressed plants. Therefore, P application can improve the photosynthetic capacity by regulating the redistribution of energy absorbed by PSII antennae and independently activating of the H2O2-scavenging function of AsA to alleviate oxidative damage in F. rufa plants, thereby improving their survival under water stress conditions.

Latitude, climate and vegetation type are key factors in the distribution of soil nematodes. The diversity of most aboveground organisms increases with decreasing latitude, but the macro-ecological diversity and geographic distribution patterns of belowground animals have been poorly studied. The large-scale geographic distribution patterns of soil nematodes were examined in terms of their abundance and their driving forces, with a view towards ascertaining whether the large-scale patterns (LSP) of distribution and diversity of soil nematodes were driven by latitude, climate and vegetation type. A literature review representing multiple vegetation types across latitudinal gradients was conducted, and information was gathered pertaining to soil nematodes throughout the globe. Different databases, such as Google Scholar, Web of Sciences, Scopus and PubMed, were searched to collect data published in English-language journals. A correlational analysis between soil nematode diversity and latitude, mean annual precipitation and mean annual temperature was performed. The present review also compared the abundance and genus of soil nematodes among different vegetation types. The LSP of the soil nematodes was unimodal, and a higher nematode abundance was recorded at latitudes between 30 and 55°. A significant correlation was observed between the latitude and species richness index, whereas latitude explained 65.9% of the variation in the species richness index across plots. Nematode abundance showed a distinct peak at a mean annual temperature of approximately 8 °C, but no significant correlation was found between the nematode abundance and mean annual precipitation. The highest mean value of soil nematode abundance was recorded in temperate coniferous forests, followed by tropical forest, grassland, temperate broadleaf forest, crop field and garden, desert and polar vegetation types. The mature index of soil nematodes was negatively correlated with latitude. A redundancy analysis (RDA) showed that the composition of the trophic group of the soil was greatly influenced by latitude (LA) and mean annual precipitation (MAP). The number of the soil nematode genera was found to be highest in temperate broadleaf forests, followed by tropical forest, grassland, temperate coniferous forest, crop field and garden, desert and polar vegetation types. Soil nematodes exhibited large-scale distribution patterns along latitudes on a global scale as a result of hydrothermal conditions, plant growth and human activities.

As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns., This research was supported by a grant from DOB Ecology to T.W.C., a grant from the Netherlands Organization for Scientific Research (grant 016.Veni.181.078) to S.G., grants from NSF (OPP 1115245, 1341736, 0840979) to B.J.A., by a Ramon y Cajal fellow award (RYC-2016-19939) to R.C.H., a grant from UNEP & Global Environment Facility to J.E.C., grants from NERC’s Soil Security Programme to R.D.B. (NE/M017028/1) T.C. (NE/M017036/1), a grant from FAPEMIG/FAPESP/VALE S.A.(CRA-RDP-00136-10) to L.B.C., through the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) awarded to S.R.C., a grant from CNPq PROTAX (562346/2010-4) to J.M.d.C.C., a grant from DFG (CRC990) to V.K. and S.S., a grant from the MSHE of Russia (AAAA-A17-117112850234-5) to A.A.K., grants from the Chinese Academy of Sciences (XDB15010402) and the National Natural Science Foundation of China (41877047) to Q.L., grants from the National Natural Science Foundation of China (31330011, 31170484) to W.L., grants from NERC (NE/ M017036/1) to M.M., grants from the Spanish Ministry of Innovation (CGL2009-14686-C02-01/02, CGL2013- 43675-P) to J.A.R.M., grant from the Spanish Ministry of Innovation (RYC-2016-19939) to R.C.H., grants from NSF (DEB-0450537, DEB-1145440) to P.M., T.O.P. and K. Powers, grants from the German Academic Exchange Service (PKZ 91540366) and NAFOSTED (106.05–2017.330) to T.A.D.N., by an ARC Discovery project (DP150104199) to U.N.N., by the National Key Research and Development Program of China (2016YFC0502101) and the National Natural Science Foundation of China (31370632) to K. Pan, a ERC Research Council Advanced grant (ERC-Adv 323020 SPECIALS) to W.H.v.d.P, a grant from the Natural Environment Research Council (NERC) to D.G.W., a grant from BAPHIQ (106AS-9.5.1-BQ-B3) to J.-i.Y., a grant from the Russian Foundation for Basic Research (18-29-05076) to A.V.T. The James Hutton Institute receives financial support from the Scottish Government Rural and Environment Science and Analytical Services (RESAS) division. Investigations in Northwest Russia were carried out under state order for IB KarRC RAS and are partially supported by the Russian Foundation for Basic Research (18-34-00849).

Ammonia oxidizing bacteria (AOB), Ammonia oxidizing archaea (AOA) and methane oxidizing bacteria (MOB) play cogent roles in oxidation and nitrification processes, and hence have important ecological functions in several ecosystems. However, their distribution and compositional differences in different long-term flooded paddy fields (FPFs) management at different soil depths remains under-investigated. Using qPCR and phylogenetic analysis, this study investigated the abundance, niches, and compositional differences of AOA, AOB, and MOB along with their potential nitrification and oxidation rate in three soil layers from three FPFs (ShaPingBa (SPB), HeChuan (HC), and JiDi (JD)) in Chongqing, China. In all the FPFs, CH4 oxidation occurred mainly in the surface (0&ndash, 3 cm) and subsurface layers (3&ndash, 5 cm). A significant difference in potential methane oxidation and nitrification rates was observed among the three FPFs, in which SPB had the highest. The higher amoA genes are the marker for abundance of AOA compared to AOB while pmoA genes, which is the marker for MOB abundance and diversity, indicated their significant role in the nitrification process across the three FPFs. The phylogenetic analysis revealed that AOA were mainly composed of Nitrososphaera, Nitrosospumilus, and Nitrosotalea, while the genus Nitrosomonas accounted for the greatest proportion of AOB in the three soil layers. MOB were mainly composed of Methylocaldum and Methylocystis genera. Overall, this finding pointed to niche differences as well as suitability of the surface and subsurface soil environments for the co-occurrence of ammonia oxidation and methane oxidation in FPFs.

Intercropping may improve community stability and yield under climate change. Here, we set up a field experiment to evaluate the advantages of cultivating Z anthoxylum bungeanum with Capsicum annum, and Z. bungeanum with Glycine max as intercrops, compared with cultivating Z. bungeanum in monoculture. Effects of extreme drought stress conditions on morphological, physiological, and biochemical traits of the three crop species cultivated in the three contrasting planting systems were compared. Results showed that extreme drought conditions induced negative impacts on Z. bungeanum grown in monoculture, due to reduced growth and metabolic impairment. However, limited stomatal conductance, reduced transpiration rate (Tr), and increased water use efficiency, carotenoid content, catalase activity, and accumulation of soluble sugars in Z. bungeanum indicated its adaptive strategies for tolerance of extreme drought stress conditions. Compared with cultivation in monoculture, intercropping with C. annum had positive effects on Z. bungeanum under extreme drought stress conditions, as a result of improved crown diameter, leaf relative water content (LRWC), net photosynthetic rate, and proline content, while intercropping with G. max under extreme drought stress conditions increased net CO2 assimilation rates, LRWC, Tr, and superoxide dismutase (SOD) activity. In conclusion, Z. bungeanum has an effective defense mechanism for extreme drought stress tolerance. Intercropping with G. max enhanced this tolerance potential primarily through its physio-biochemical adjustments, rather than as a result of nitrogen fixation by G. max.

Studying the pattern of species richness is crucial in understanding the diversity and distribution of organisms in the earth. Climate and human influences are the major driving factors that directly influence the large‐scale distributions of plant species, including gymnosperms. Understanding how gymnosperms respond to climate, topography, and human‐induced changes is useful in predicting the impacts of global change. Here, we attempt to evaluate how climatic and human‐induced processes could affect the spatial richness patterns of gymnosperms in China. Initially, we divided a map of the country into grid cells of 50 × 50 km2 spatial resolution and plotted the geographical coordinate distribution occurrence of 236 native gymnosperm taxa. The gymnosperm taxa were separated into three response variables: (a) all species, (b) endemic species, and (c) nonendemic species, based on their distribution. The species richness patterns of these response variables to four predictor sets were also evaluated: (a) energy–water, (b) climatic seasonality, (c) habitat heterogeneity, and (d) human influences. We performed generalized linear models (GLMs) and variation partitioning analyses to determine the effect of predictors on spatial richness patterns. The results showed that the distribution pattern of species richness was highest in the southwestern mountainous area and Taiwan in China. We found a significant relationship between the predictor variable set and species richness pattern. Further, our findings provide evidence that climatic seasonality is the most important factor in explaining distinct fractions of variations in the species richness patterns of all studied response variables. Moreover, it was found that energy–water was the best predictor set to determine the richness pattern of all species and endemic species, while habitat heterogeneity has a better influence on nonendemic species. Therefore, we conclude that with the current climate fluctuations as a result of climate change and increasing human activities, gymnosperms might face a high risk of extinction., China is one of the global biodiversity hot spot and an important ecological region to study the distribution of gymnosperms including endemic species. Here in this study, we try to evaluate the role of environmental‐ and human‐induced variables in determining the spatial pattern of species richness of gymnosperms. Our findings support that spatial richness pattern of all species of gymnosperms in China is mainly favored by climatic seasonality while energy–water and habitat heterogeneity variables have profound effect on endemic and nonendemic species, respectively.

Due to the low efficiency of the current measurement of water quality, we designed a hexacopter that can automatically measure water quality. The dynamic model of hexacopter is derived using Newton-Eulerian’s law. In order to ensure the stability of the drone when hovering over the surface of the water, dynamic inversion control (DIC) based on nonlinear feedback is proposed to control the attitude of the UAV. To further reduce the long settling time and overshoot of the controller, an error compensator based on proportional integral derivative (PID) is introduced in the control system. Simulation result shows the good performance of the proposed DIC-PID algorithm comparing to the system without error compensated controller. The designed water quality measurement system can sample and analyze the water quality in real time. Details of the water quality measurement system are presented to verify the high-efficiency of the designed UAV.

Cancer is a serious health problem and the second leading cause of death around the globe. Present review is an attempt to provide utmost information based on ethno-pharmacological and toxicological aspects of anti-cancer plants of the world. A total of 276 articles published in English journals and containing maximum ethnomedicinal information were reviewed using several data sources such as; Google scholar, Web of Science, Scopus, PubMed and floras of different countries. A total of 199 anti-cancer plants were recorded in present review and results indicated that traditional medicines are mostly being use in developing countries for cancer treatment. Traditionally and scientifically skin and breast cancer types gained more focus. Seventy plants were reportedly analyzed for in-vitro activities while 32 plants were having in-vivo reports. Twenty nine pure compounds (mostly phenolic) were reportedly isolated from anti-cancer plants and tested against different cancer cell lines. Inspite having better efficiency of ethnomedicines as compared to synthetic drugs, several plants have also shown toxic effects on living system. Therefore, we invite researchers attention to carry out detailed ethno-pharmacological and toxicological studies on un-explored anti-cancer plants in order to provide reliable knowledge to the patients and develop novel anti-cancer drugs. Copyright © 2017 John Wiley & Sons, Ltd.

Aim of the present research is to investigate the effect of nitrogen (N) and phosphorus (P) on soil food webs (microbes, nematodes and microarthropods) trophic interactions in agriculture ecosystems. A complete randomized block design experiment of N and P fertilization was initiated in 2010 with four treatments: (1) P-addition, (2) N-addition, (3) NP-addition and (4) control. After 4 years of fertilization, compared with control, N-addition had a negative effect on microarthropods and clarify indirectly by significantly (P

Changes to global climate patterns have the potential to alter the structure of soil microbial communities which are key components of terrestrial ecosystems. High altitude ecosystems are both temperature and Nitrogen-limited and the biota therein is sensitive to these conditions. Temperatures and nitrogen (N) depositions in the eastern Qinghai–Tibet Plateau are predicted to sharp rise by the end of this century. This study aimed to better understand the effects of warming and N addition treatments alone and in combination on an alpine meadow ecosystem near the timberline zone in the eastern region of the Qinghai–Tibet Plateau. The field experiment included replicated plots with an ambient treatment alone or with low N (5 g N m −2 a −1 ), intermediate N (15 g N m −2 a −1 ), and high N (30 g N m −2 a −1 ) (Control, LN, MN, HN) and open top chambers warming treatment alone, or LN and HN additions (W, WLN, WHN) to study the interactive effects of the warming and N additions on the soil microbial community as determined by phospholipid fatty acids (PLFAs). Microbial communities and their allied soil and plant properties were examined after 3 years of the treatments. The strength of the relationship between the treatments and their direct and indirect effects on the microbial communities, soil and plant properties were determined using a structural equation model (SEqM). The results indicated that N addition significantly changed surface soil microbial communities, in particular, decreased the fungi: bacteria ratio (F:B) ( p p p

Abies georgei var. smithii (Abies George I varsmithorr. II (Viguie et Gaussen) Cheng et l.) belongs to Abies of Pinaceae, which is distributed in the southeast of Tibet, southwest of Sichuan and northwest of Yunnan. In this study, Abies georgei var. smithii in Sejila Mountain of southeastern Tibet was studied, the contents of Malondialdehyde (MDA), proline (pro), hydrogen peroxide (H2O2), soluble sugar and chlorophyll as well as the activities of superoxide dismutase (SOD) and superoxide dismutase (SOD) in the leaves, twigs, tree stems and roots of Abies georgei var. smithii were measured at different altitudes in the growing and non-growing seasons, single factor analysis of variance and multiple comparison were used to process the data. The results showed that the contents of Malondialdehyde (MDA), proline (pro) and hydrogen peroxide (H2O2) in the roots of Abies georgei var. smithii were significantly higher than those of other tissues in both growing and non-growing seasons, the content of chlorophyll in the leaves increased at first and then decreased with the elevation gradient, on the contrary, the ratio of chlorophyll a/b (CHLA/CHLB) increased with the elevation gradient. The activities of Peroxidase (POD) and superoxide dismutase (SOD) were the lowest. When the altitude was more than 4300m, the activities of POD and SOD decreased. The results showed that the physiological resistance of Abies georgei var. smithii decreased when the elevation was over 3900m, which was not beneficial to the growth and development of Abies georgei var. smithii, therefore, the distribution of Abies georgei var. smithii along the higher elevation gradient was limited by the unfavorable environmental factors at high altitude.

Forest fire is a recurrent and serious problem which stirs major environmental, economic, and social concerns. Information on the temporal-spatial distribution of ignition probability and identifying the factors that drive the pattern of forest fire occurrences are the most challenging issues over the world. In this study, the spatial distribution and temporal variation in forest fire occurrence were examined by applying the Maximum Entropy (Maxent) algorithm. Redundancy analyses were used to determine the contributions of driving factors (forest fire policy, human interventions, and biophysical variables) to the forest fire occurrences. In addition, the strength of the relationship between the forest fire policy, human interventions, and biophysical variables and their direct and indirect effects on forest fire occurrences were determined using structural equation models (SEMs). Our results showed the Maxent model was suitable for predictive modeling of the distribution of forest fire occurrences in southwestern China. The predicted area of forest fire occurrences in southwestern China during 2000-2017 was 3.25 x 10(5) km(2) which mostly concentrated in the southern region. There was an increasing trend of forest fire crossing national and provincial borders. According to the temporal pattern of forest fire occurrences, additional ignition probability areas including the central Yunnan and the eastern Sichuan were found in spring when compared to those in winter. Moreover, forest fire policy is the main driver underlying the ignition, followed by biophysical factors and human interventions. These should be considered as key elements in the design of forest fire prevention programmes. Although the explanatory power of driving factors varied, national border distance (NBD) and conductive index (CI) that represented effects of forest fire policy were constantly the key driving variables. In addition, there is heterogeneity among the biophysical factors. The meteorological factors significantly affected on ignition probability in different temporal scale, while the effects of topographic factors were smaller. Human interventions had no significant direct effect on ignition probability, while they via fire policy had a significant positive indirect effect on the probability of fire occurrence. The results suggest that we should strengthen the administrative capacities to prevent forest fires, and improve the fire prevention publicity and education on the residents living near the national border and/or in low population density areas to get higher awareness and compliance of forest fire policies for local residents.

Land use/land cover (LULC) changes impact the structure and functioning of ecosystems, which consequently influences the provisioning of a range of ecosystem services (ES). There is a growing consensus regarding the merit of integrating the evaluation of ES into regional policy planning. The Yangtze River is the world's third longest and supports more than 6% of its population. However, assessing the potential impacts of different resource management policies upon ES is complicated in the Yangtze basin. To remedy this, here we designed a scenario analysis-based approach that used remotely sensed data and GIS (geographic information system) to analyze the relationships between ES (i.e., water flow regulation, water purification) and policies envisioned to improve human welfare in the Chongqing municipality, in the upper reaches of the Three Gorges Reservoir Area (TGRA) in the Yangtze basin. This watershed area has high population density and suffers from severe flood hazard and critical pollution issues. The GEOMOD modeling technique was used to predict LULC changes according to policy planning alternatives, producing scenarios by 2050 for the TGRA watershed. The GIS-based ES model (InVEST model) was developed as a tool to inform the decision-making process with the intention of aligning conservation measures with economic development. We examine policy effectiveness by comparing three scenarios for 2050: scenario-1 maintains the current policy, with no considerations of ES; scenario-2 integrates ES into policy planning; and scenario-3 integrates ES into policy planning considering the needs of local people. Our scenario-based LULC change analysis showed that the land with large increases in water flow regulation (i.e., values ≤-3000 × 10

Alnus cremastogyne, a broad-leaved tree endemic to south-western China, has both commercial and restoration importance. However, little is known of its morphological, physiological and biochemical responses to drought and phosphorous (P) application. A randomized experimental design was used to investigate how drought affected A. cremastogyne seedlings, and the role that P applications play in these responses. Drought had significant negative effects on A. cremastogyne growth and metabolism, as revealed by reduced biomass (leaf, shoot and root), leaf area, stem diameter, plant height, photosynthetic rate, leaf relative water content, and photosynthetic pigments, and a weakened antioxidative defence mechanism and high lipid peroxidation level. However, the reduced leaf area and enhanced osmolyte (proline and soluble sugars) accumulation suggests drought avoidance and tolerance strategies in this tree. Applying P significantly improved the leaf relative water content and photosynthetic rate of drought-stressed seedlings, which may reflect increased anti-oxidative enzyme (superoxide dismutase, catalase and peroxidase) activities, osmolyte accumulation, soluble proteins, and decreased lipid peroxidation levels. However, P had only a slight or negligible effect on the well-watered plants. A. cremastogyne is sensitive to drought stress, but P facilitates and improves its metabolism primarily via biochemical and physiological rather than morphological adjustments, regardless of water availability., Instituto de Fisiología Vegetal

Land use/Land cover (LULC) changes as a result of policy planning influence ecosystem structures, processes, and functions, which are the basis for providing a wide range of ecosystem services (ES). There is an increasing consensus about the importance of integrating ES into ecological policy but quantifying the potential impacts of different policy on ES has proven difficult. We designed a remote sensing, geographic information system and scenario analysis-based approach to estimate and analyze the relationship between ES (soil conservation and carbon sequestration) and ecological policy designed to improve human welfare in the Chongqing municipality in the upper reaches of the Three Gorges Reservoir Area, China, a densely populated, highly modified watershed with serious soil erosion and flood hazard. Three alternative scenarios in 2050 were modeled for the Three Gorges Reservoir Area watershed. The model GEOMOD was used to predict future LULC changes due to policy planning. The ES models (Universal Soil Loss Equation model and Carnegie-Ames-Stanford Approach model) were designed to inform decisions, with an aim to align economic forces with conservation. We examine policy effectiveness by comparing scenarios for 2050 (Scenario1: Maintain current policy with no considerations of ES, Scenario2: Integrate ES into policy planning, Scenario3: Integrate ES into policy planning in view of the need of local people). Scenario-based LULC change analysis revealed that if the current afforestation policy continues (scenario 1), total ES would be further increased in 2050 due to expansion of forest cover. However, by targeting policy to improve ES provision (scenarios 2 and 3), ecological risks of soil loss can be significantly reduced and carbon sequestration enhanced. Scenario 3, thus, provided the best future environmental development scenario considering the need of local people in each region for ES. This scenario will theoretically help the Three Gorges Dam to harvest more ecological benefits through improvements in soil conservation and carbon sequestration. This study highlights the observation that including ES in policy planning and has a great potential to generate opportunities to maximize ES. This study highlights that including ES in policy planning has a great potential to generate opportunities to maximize ES. Hence, there is a need to encourage proper implementation of ecological policy to maintain and improve ES.

Recently, quadrotor has become one of the hotspots in robot research. To design an efficient controller for a quadrotor UAV is always challenging to for its under-actuated, strong coupling and nonlinearity. In this paper, a double closed-loop cascaded linear quadratic regulator (LQR) controller is proposed to track the referred position and attitude respectively. In order to solve the problem of tedious parameter setting, a parameter self-tuning control structure based on Simultaneous Perturbation Stochastic Approximation (SPSA) is designed and the parameters in the position and attitude controller are optimized respectively. By comparing with the original LQR controller, the simulation results show that the parameter-optimized controller improves the dynamic performance and control effect both in position control and attitude control, which verifies the correctness and feasibility of the proposed method.

Polybrominated diphenyl ethers (PBDEs) are extremely incessant anthropogenic contaminants found in the environment, with dreadful risk to aquatic ecosystems. However, there is a limited amount of data concerning their impacts on freshwater organisms. 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) are significant components of total PBDEs in water. The sublethal effects of BDE-47, BDE-209 and their binary mixtures on the aquatic organism Daphnia magna were investigated in acute and chronic exposure experiments. Immobilization and heartbeat were studied in daphnids after 48 h of exposure. Mortality rate, breed number, Cholinesterase (ChE), Glutathione S-transferases (GST) and Catalase (CAT) activities were evaluated after 21 days of exposure. The results showed that at 100 and 200 μg/L concentration of BDE-47, immobilization rate of daphnids were inhibited by 44.0 ± 16.7% and 88.0 ± 10.9%, respectively. The binary mixture of BDE-47 and BDE-209 had uncongenial effects on immobilization of D. magna under acute toxicity test. BDE-209 significantly increased the heartbeat rate of daphnids, which increased even further when combined with BDE-47. After 21 days of exposure, daphnids exposed to single BDE-47 were physiologically altered. The combination of BDE-47 with BDE-209 significantly decreased the mortality rate of daphnids. Irrespective of the concentration, higher numbers of offsprings were produced in the mixtures compared to BDE-47 treatment alone. ChE activities significantly (p 0.05) decreased at concentrations of 2 and 4 μg/L in single BDE-47 treatment, while GST activity significantly (p 0.05) decreased at 0.5 μg/L. CAT activities significantly increased with BDE-47 treatments in all the tested concentrations (p 0.05). The mixtures significantly affect ChE (p 0.05), GST (p 0.05) and CAT activities (p 0.05). The results illustrated that the toxicity of the mixture of PBDE congeners exposed to aquatic organisms may have antagonistic effects. The 21 days chronic test in this study suggests that acute toxicity tests, i.e. 48-h tests, using Daphnia may lead to underestimation of risks associated with PBDEs, especially, BDE-209. Hence, there is a necessity to re-examine PBDE congeners' environmental risk in aquatic organisms.

Dwarf bamboo (Fargesia rufa Yi), one of the staple foods for the endangered giant pandas, is highly susceptible to water deficit due to its shallow roots. In the face of climate change, maintenance and improvement in its productivity is very necessary for the management of the giant pandas' habitats. However, the regulatory mechanisms underlying plant responses to water deficit are poorly known. To investigate the effects of P application on photosynthetic C and N metabolism, water use efficiency (WUE) and growth of dwarf bamboo under water deficit, a completely randomized design with two factors of two watering (well-watered and water-stressed) and two P regimes (with and without P fertilization) was arranged. P application hardly changed growth, net CO2 assimilation rate (P(n)) and WUE in well-watered plants but significantly increased relative growth rate (RGR) and P(n) in water-stressed plants. The effect of P application on RGR under water stress was mostly associated with physiological adjustments rather than with differences in biomass allocation. P application maintained the balance of C metabolism in well-watered plants, but altered the proportion of nitrogenous compounds in N metabolism. By contrast, P application remarkably increased sucrose-metabolizing enzymes activities with an obvious decrease in sucrose content in water-stressed plants, suggesting an accelerated sucrose metabolism. Activation of nitrogen-metabolizing enzymes in water-stressed plants was attenuated after P application, thus slowing nitrate reduction and ammonium assimilation. P application hardly enlarged the phenotypic plasticity of dwarf bamboo in response to water in the short term. Generally, these examined traits of dwarf bamboo displayed weak or negligible responses to water-P interaction. In conclusion, P application could accelerate P(n) and sucrose metabolism and slow N metabolism in water-stressed dwarf bamboo, and as a result improved RGR and alleviated damage from soil water deficit.

Differential regulations of C and N metabolism in dwarf bamboo improve the capacity of osmotic adjustment, and also their metabolites may play an important role for protection against membrane lipid peroxidation under drought, thus accelerating recovery after rewatering. Dwarf bamboo (Fargesia rufa Yi), is a staple food for the endangered giant panda, but little is known about the impact of drought on bamboo species and its recovery mechanism. This study investigated the response of carbon (C) and nitrogen (N) metabolism to drought and subsequent recovery, and the relationship of their metabolites with lipid peroxidation. Photochemistry was reversibly down-regulated after drought, but a longer recovery time is needed. The accelerated degradation of starch due to a rapid increase in amylase activity resulted in higher soluble sugar only in severe drought-stressed plants after 30 days of drought. Sucrose content was not affected by drought because of the relative increases in activities of invertase, sucrose synthase, and sucrose phosphate synthase. As nitrate concentration increased in parallel with nitrate reductase activity, ammonium (NH4 +) production was enhanced by drought. Also, activated glutamine synthetase/glutamate synthase cycle stimulated NH4 + assimilation, while hydrolysis of soluble proteins was accelerated, resulting in accumulation of amino acids. After rewatering, re-balancing of C metabolism has gradually begun, but a stronger N metabolism was still observed. The notable positive correlations between MDA and the contents of starch and proline after 15 days of drought as well as between MDA and the contents of soluble sugar, NSC and proline after 30 days of drought were displayed. We conclude that dwarf bamboo may not only differently regulate its C and N metabolism to improve the capacity of osmotic adjustment but also employ its different metabolites protect against membrane lipid peroxidation under different intensities and duration of drought, thus accelerating its recovery after rewatering.

Three Gorges Reservoir in China was running since June 2003, and its impacts on soil erosion (SE) and soil conservation (SC) have attracted major public attentions. We quantified the soil conservation service of ecosystems in the Three Gorges Reservoir Area (TGRA) based on a GIS platform using the universal soil loss equation. We revealed the changes of spatial and temporal patterns of soil conservation (SC) and soil erosion (SE) after project construction as well as impact factors on local SE and SC. Results showed that the total amounts and mean capacity of soil conservation services in the TGRA were 15.38-billion t a−1 and 2134.73 t ha−1 a−1, respectively. Northeast reservoir area owned better services than the southwest, and the regions with a capacity of >5000 t ha−1 a−1 were primary located in mountain areas. An increasing trend in SC appeared in the TRGA and “with increasing SC” totaled 22690.5 km2 (38.9%), while the areas “with decreasing SC” amounted to 3460.4 km2 (5.9%) between 2000 and 2010. Moreover, the pattern of changing SC was continuous in this area. The spatial characteristics of soil conservation service in the TGRA were primarily affected by slope, climate and terrain features. In addition, the reforestation and/or forest protection would contribute to soil erosion control in the TGRA. The results revealed a great spatial heterogeneity of soil conservation service in this region, which may provide useful suggestions for land management, soil erosion control and ecosystem protection in the TGRA in China.

Sweet potato is a high-yield food crop with strong adaptation and is widely cultivated in southwestern China. Adjusting crop planting distance and planting density to improve the yield and productivity of intercropping systems has become an important management practice around the globe. However, little is known about the response of the sweet potato yield and photosynthetic characteristics to intercropping with walnut saplings. Field experiments were conducted in a split-plot arrangement, e.g., three plant densities (Dl, low, 4 plants/m2; Dm, moderate, 8 plants/m2; and Dh, high, 12 plants/m2) were randomly assigned (subplot) to three planting distances (P1, 0.25 n; P2, 0.5 n; and P3, n) (main plot). The results showed that with increasing plant distance, the yield of high-density sweet potatoes decreased significantly (P

A laboratory microcosm experiment was conducted to evaluate the effects of the four single-species (Pinus tabulaeformis (Pt), Pinus radiata (Pr), Cercidiphyllum japonicum (Cj), and Ostryopsis davidiana (Od) litters from southwestern China and mixed pine-broadleaf (Pt + Cj, Pr + Cj, Pt + Od, Pr + Od) litters on soil microbial activities and dissolved organic carbon (DOC). Microcosms with the local typical soil and litterbags containing the eight litter types were incubated with 60% water field capacity for 84 days at 20 C. The results showed that the dynamics of soil microbial parameters and DOC were influenced by the litter types with different initial chemical quality. Due to their initial poor nutrient contents, the Pt and Pr litter treatments always showed lower soil microbial activities and DOC at each sampling compared with the Cj and Od litter treatments. However, compared with the single-species pine litter treatments, the inclusion of broadleaf Cj or Od litter into pine litter significantly increased soil microbial activities, and the concentrations of soil DOC during the whole incubation process. The current work thus provided a good implication for plantation management that it should be appropriate to consider Cj as an ameliorative species or retain Od in the pine plantations to improve soil conditions.

The responses of the antioxidant defense system in plant species to drought stress are still relatively unknown. In order to further understand how the system responds to drought stress, the leaves of Fargesia denudata seedlings were investigated. Antioxidant enzyme activities, antioxidant contents, hydrogen peroxide (H2O2), superoxide anion (O 2 ·− ) and MDA contents in the seedling leaves were measured under well-watered (WW), moderate drought-stressed (MD), and severe drought-stressed (SD) treatments. Although drought stress significantly increased H2O2 and O 2 ·− levels in F. denudata leaves, only weak lipid peroxidation was observed. This is attributed to the higher superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) activities in F. denudata leaves during the entire drought period. Reduced and oxidized ascorbate (AsA and DHA) contents were almost not affected by drought except that DHA under SD showed an obvious increase on day 30. Furthermore, reduced glutathione (GSH) content under drought stress significantly decreased, while oxidized glutathione (GSSG) markedly increased under SD on days 30 and 45 as well as under MD on day 30; as a result, the ratio GSH/GSSG declined considerably. These results indicated that GSH was involved in scavenging H2O2 and O 2 ·− under drought stress and it was more sensitive to drought stress in scavenging H2O2 and O 2 ·− than AsA. As a result, a highly efficient antioxidant defense system in drought-stressed F. denudate leaves operated mainly through the synergistic functioning of SOD, CAT, APX, MDHAR, DHAR, GR, and GSH against oxidative damage.

The distribution of forests can be hindcast or forecast when robust data and validation proofs are available. Distribution consequences for temperate coniferous forests during the Quaternary and future climatic fluctuations are little understood in China. Temperate coniferous forests are subdivided into two types where Pinus, Keteleeria, Tsuga and Cupressus species characterize the warm forests while Abies, Picea, Larix and Juniperus species characterize the cold forests. Both forest types were investigated using 12,675 unique records in the MaxEnt model to infer distribution patterns during six time periods: the present time, mid-Holocene, Last Glacial Maximum, Last Interglacial and the near- and far-future (2050, 2070). The results showed that the mean temperature of the driest quarter, followed by the temperature annual range and the precipitation of the warmest quarter were the most important variables controlling forests distribution. Suitable areas capable of supporting the presence of warm coniferous forests were highly contracted during the Quaternary; meanwhile, the cold coniferous forests expanded westwards from the last glacial maximum through the mid-Holocene to the present. The predicted future distributions showed a significant range-shift of warm forests northeastwards in response to climate change while cold coniferous forests are expected to migrate towards the Tibetan Plateau. Under increased global warming, the bioclimatic variables of the past and future periods were used as ecological indicators for the identification of areas showing “climatic stability”, and predicted to be refugia for coniferous forests and as good tools for conservation planning in Sichuan and the Hengduan-Tibetan migration corridor.

Dwarf bamboo is an ecologically and economically important forest resource that is widespread in mountainous regions of eastern Asia and southern America. Fargesia denudata, one of the most important dwarf bamboos, is a staple food of the giant panda, but our knowledge about how F. denudata copes with drought stress is very limited. The objective of this study was to determine the responses of carbon (C) and nitrogen (N) metabolism to drought in leaves and roots of F. denudata plants. Plants were subjected to three water treatments, well-watered [WW, 85 % relative soil water content (RSWC)], moderate drought (MD, 50 % RSWC), and severe drought (SD, 30 % RSWC), for two consecutive years during the sprouting period. Plant growth parameters, levels of carbohydrates and N compounds, and activities of key enzymes involved in C and N metabolism were analyzed. In young leaves, C metabolism was in balance after drought stress, but nitrate (NO3−) reduction and ammonium (NH4+) assimilation were accelerated. In old leaves, drought stress decreased carbohydrate contents by spurring the activities of the main enzymes that participate in C metabolism, whereas N metabolism was enhanced only under SD. Roots showed unchanged C metabolism parameters under MD, together with stable NO3− reduction and the key enzymes related to NH4+ assimilation, whereas they were stimulated by SD. Hydrolysates of carbohydrates in old leaves could be transferred into roots, but only to meet MD. Meanwhile, roots could allocate more N nutrition to young leaves and less to old leaves. These changes regulated the overall metabolic balance of F. denudata. Consequently, the results indicate that different organs with various response strategies will be well adapted to different drought intensities for ensuring regular growth of F. denudata plants at the whole-plant level.

Environmental pollution with heavy metals is a serious issue worldwide posing threats to humans, animals and plants and to the stability of overall ecosystem. Chromium (Cr) is one of most hazardous heavy metals with a high carcinogenic and recalcitrant nature. Aim of the present study was to select low-cost biosorbent using wheat straw and Eupatorium adenophorum through simple carbonization process, capable of removing Cr (VI) efficiently from wastewater. From studied plants a low cost adsorbent was prepared for removing Cr (VI) from aqueous solution following very simple carbonization method excluding activation process. Several factors such as pH, contact time, sorbent dosage and temperature were investigated for attaining ideal condition. For analysis of adsorption equilibrium isotherm data, Langmuir, Freundlich and Temkin models were used while pseudo-first-order, pseudo-second-order, external diffusion and intra-particle diffusion models were used for the analysis of kinetic data. The obtained results revealed that 99.9% of Cr (VI) removal was observed in the solution with a pH of 1.0. Among all the tested models Langmuir model fitted more closely according to the data obtained. Increase in adsorption capacity was observed with increasing temperature revealing endothermic nature of Cr (VI). The maximum Cr (VI) adsorption potential of E. adenophorum and wheat straw was 89.22 mg per 1 gram adsorbent at 308K. Kinetic data of absorption precisely followed pseudo-second-order model. Present study revealed highest potential of E. adenophorum and wheat straw for producing low cost adsorbent and to remove Cr (VI) from contaminated water.

An agroforestry experiment was conducted that involved four planting systems: monoculture of the focal species Zanthoxylum bungeanum and mixed cultures of Z. bungeanum and Capsicum annuum, Z. bungeanum and Medicago sativa and Z. bungeanum and Glycine max. Soil microbial food web (microorganisms and nematodes) was investigated under manipulated extreme rainfall in the four planting systems to assess whether presence of neighbor species alleviated the magnitude of extreme rainfall on nutrient uptake of the focal species by increasing the stability of soil food web. Our results indicate that in the focal species and G. max mixed culture, leaf nitrogen contents of the focal species were higher than in the monoculture and in the other mixed cultures under extreme rainfall. This result was mainly due to the significant increase under extreme rainfall of G. max species root biomass, resulting in enhanced microbial resistance and subsequent net nitrogen mineralization rate and leaf nitrogen uptake for the focal species. Differences in functional traits of neighbors had additive effects and led to a marked divergence of soil food-web resistance and nutrient uptake of the focal species. Climate change can indirectly alleviate focal species via its influence on their neighbors.

Dwarf bamboo-dominated forests are often subjected to temporary periods of drought due to rising air temperature and decreasing rainfall. Nevertheless, the relationship among CO2 assimilation, photoprotective pathways and metabolism of reactive oxygen species (ROS) remains unexplored in bamboo species. Changes in leaf gas exchange, chlorophyll fluorescence, energy partitioning, antioxidative system and compounds related to ROS metabolism in Fargesia rufa plants subjected to drought and subsequent rewatering were analyzed. Drought resulted in a reversible inhibition of photochemistry, particularly net CO2 assimilation, and lipid peroxidation due to ROS accumulation. Meanwhile, photoprotective pathways, including the water–water cycle (especially for moderate drought), and adjustment in antenna pigments, thermal dissipation and antioxidative defense capacity at organelle levels (especially for severe drought), were up-regulated at the stress phase. Conversely, photorespiration was down-regulated after drought stress. As a result, rewatering restored most of the photochemical activity under drought, especially moderate drought. Moreover, thermal dissipation under severe drought was still operated for avoiding high ROS levels after rewatering. Therefore, the synergistic function of these photoprotective pathways except photorespiration can protect the photosynthetic apparatus from oxidative damage in response to varying intensities of drought stress when CO2 assimilation is restricted. This is helpful for the gradual recovery of photosynthetic capacity after rewatering. Thus, F. rufa plants can withstand drought and is capable of survival in such environment. Highlights: 1. The effects of drought and subsequent rewatering on Fargesia rufa were studied. 2. Drought resulted in a reversible inhibition of photochemistry. 3. Photoprotective pathways except photorespiration were up-regulated at the drought phase. 4. Rewatering rapidly restored photochemical activity, especially under moderate drought. 5. Fargesia rufa plant is capable of resisting and surviving drought environment.

Background Leishmaniasis and malaria are the two most common parasitic diseases and responsible for large number of deaths per year particularly in developing countries like Pakistan. Majority of Pakistan population rely on medicinal plants due to their low socio-economic status. The present review was designed to gather utmost fragmented published data on traditionally used medicinal plants against leishmaniasis and malaria in Pakistan and their scientific validation. Methods Pub Med, Google Scholar, Web of Science, ISI Web of knowledge and Flora of Pakistan were searched for the collection of data on ethnomedicinal plants. Total 89 articles were reviewed for present study which was mostly published in English. We selected only those articles in which complete information was given regarding traditional uses of medicinal plants in Pakistan. Results Total of 56 plants (malaria 33, leishmaniasis 23) was found to be used traditionally against reported parasites. Leaves were the most focused plant part both in traditional use and in in vitro screening against both parasites. Most extensively used plant families against Leishmaniasis and Malaria were Lamiaceae and Asteraceae respectively. Out of 56 documented plants only 15 plants (Plasmodia 4, Leishmania 11) were assessed in vitro against these parasites. Mostly crude and ethanolic plant extracts were checked against Leishmania and Plasmodia respectively and showed good inhibition zone. Four pure compounds like artemisinin, physalins and sitosterol extracted from different plants proved their efficacy against these parasites. Conclusions Present review provides the efficacy and reliability of ethnomedicinal practices and also invites the attention of chemists, pharmacologist and pharmacist to scientifically validate unexplored plants that could lead toward the development of novel anti-malarial and anti-leishmanial drugs.

Cancer is a serious health problem and the second leading cause of death around the globe. Present review is an attempt to provide utmost information based on ethno-pharmacological and toxicological aspects of anti-cancer plants of the world. A total of 276 articles published in English journals and containing maximum ethnomedicinal information were reviewed using several data sources such as; Google scholar, Web of Science, Scopus, PubMed and floras of different countries. A total of 199 anti-cancer plants were recorded in present review and results indicated that traditional medicines are mostly being use in developing countries for cancer treatment. Traditionally and scientifically skin and breast cancer types gained more focus. Seventy plants were reportedly analyzed for in-vitro activities while 32 plants were having in-vivo reports. Twenty nine pure compounds (mostly phenolic) were reportedly isolated from anti-cancer plants and tested against different cancer cell lines. Inspite having better efficiency of ethnomedicines as compared to synthetic drugs, several plants have also shown toxic effects on living system. Therefore, we invite researchers attention to carry out detailed ethno-pharmacological and toxicological studies on un-explored anti-cancer plants in order to provide reliable knowledge to the patients and develop novel anti-cancer drugs. Copyright © 2017 John WileySons, Ltd.

The relationships between floral morphology and the particular pollinator, flower shelter function and reproductive success as well as details of the breeding system of Dendrobiuin jiajiangense were investigated at Fotang Mountains in Jiajiang County, Sichuan Province, China. D. jiajiangense is pollinator-specific, being pollinated by Andrena parvula. There exists considerable mechanical fit between the floral morphology of D. jiajiangense and A. parvula. Importantly, A. parvula uses D. jiajiangense flowers as shelter both during rainy weather and at night during sunny weather. This significantly increase the pollination success of D. jiajiangens. D. jiajiangense is self-compatible but pollinator-dependent for fruit set. Fruit set of D. jiajiangens was 100% after hand-self-pollination, but seed viability was normally greatly reduced. (C) 2012 Elsevier GmbH. All rights reserved.

†Background and Aims Allocation of resources to floral traits often declines distally within inflorescences in flowering plants. Architecture and resource competition have been proposed as underlying mechanisms. The aim of the present study is to assess the relative importance of resource competition and architectural effects in pollen and ovule production on racemes of Hosta ventricosa, an apomictic perennial herb. †Methods Combinations of two defoliation treatments (intact and defoliated) and two fruit-set treatments (nofruit and fruit) were created, and the roles of architecture and resource competition at each resource level were assessed. †Key Results Pollen and ovule number per flower increased after defoliation, but pollen to ovule ratio per flower did not change. Pollen, ovules and the pollen to ovule ratio per flower declined distally on racemes at each resource level. In the intact treatment, fruit development of early flowers did not affect either pollen or ovule number of late flowers. In the defoliated treatment, fruit development of early flowers reduced both pollen and ovule numbers of late flowers due to over-compensation caused by defoliation. Late flowers on defoliated fruit racemes produced less pollen than intact fruit racemes but the same number of ovules; therefore, the reduction in pollen number was not caused by over-compensation. In addition, the fruit-set rate of early flowers during flowering was higher in intact racemes than in defoliated racemes. †Conclusions In flowering plants, the relative importance of architecture and resource competition in allocation to pollen and ovules may vary with the resource pools or the overall resource availability of maternal plants.

Purpose Hoop pine (Araucaria cunninghamii) is a nitrogen (N)-demanding native Australian softwood plantation species. Litter quality and its effects on soil mineral N and 15N transformations have not been well studied in the hoop pine plantation and adjacent native forest. The present study was conducted to determine the impact of 15N injection depth and litter additions on the dynamics and fate of mineral 15N and also to compare the difference in litter quality, 15N dynamics, and fate between the hoop pine plantation (HP) and the adjacent native forest (NF).

The effect of enhanced ultraviolet-B on allelopathic potential of Zanthoxylum bungeanum was investigated. A significant inhibitory effect on germination rate of crop seeds under bioassay was observed at 25 g l(-1) and 50 g l(-1) by extracts from Zanthoxylum leaf both treated with enhanced ultraviolet-B radiation and untreated control. Medicago sativa and lettuce were more sensitive than radish to the extract from Zanthoxylum leaf treated with enhanced UV-B radiation, as the germination rates of M. sativa and lettuce were significantly reduced compared to control at 25 g l(-1) and 50 g l(-1), and so did alfalfa at 12.5 g l(-1). However, as for radish (Raphanus sativus) there was no significant reduction in germination rate at any concentration under bioassay compared to control. Content of UV-B absorbing compounds and total phenols in Zanthoxylum seedlings responded positively to enhanced UV-B radiation. The results suggest that the allelopathic potential of Z. bungeanum was generally improved under enhanced UV-B radiation. (c) 2008 Elsevier B.V. All rights reserved.

Hoop pine (Araucaria cunninghamii) is a nitrogen (N) demanding indigenous Australia softwood species with plantations in Southeast Queensland, Australia. Soil fertility has declined with increasing rotations and comparison study of N cycling between hoop pine plantations, and adjacent native forest (NF) is required to develop effective forest management for enhancing sustainable forest production and promoting environmental benefits. Field in situ mineral 15N transformations in these two forest ecosystems have not been studied. Hence, the present study was to compare the differences in soil nutrients, N transformations, 15N fluxes, and fate between the hoop pine plantation and the adjacent native forest. The study sites were in Yarraman State Forest (26°52′ S, 151°51′ E), Southeastern Queensland, Australia. The in situ core incubation method was used in the field experiments. Mineral N was determined using a LACHAT Quickchem Automated Ion Analyzer. 15N were performed using an isotope ratio mass spectrometer with a Eurovector elemental analyzer. All statistical tests were carried out by the SPSS 11.0 for Windows statistical software package. Soil total C and N were significantly higher in the NF than in the 53-year-old hoop pine plantation. Concentrations of NO3 – were significantly higher in the NF soil than in the plantation soil. The plantation soil had significantly higher 15N and 13C natural abundances than the NF soil. The NF soil had significantly lower C/N ratios than the plantation soil. NO3 ––N was dominated in mineral N pools in both NF and plantation soils, accounting for 91.6% and 70.3% of the total mineral N pools, respectively. Rates of net nitrification and net N mineralization were, respectively, four and three times higher in the NF soil than in the plantation soil. The 15NO3 ––N and mineral 15N were significantly higher in the NF soil than in the plantation soil. Significant difference in 15NH4 +–N was found in the NF soil before and after the incubation. The NF soil had significantly higher NO3 ––N, mineral N, total N and C but lower δ15N, δ13C, and C/N ratios than the plantation soil. Moreover, the rates of soil net N mineralization and nitrification were significantly higher, but ammonification rate was lower in the NF than in the plantation. The NF soil had many more dynamic N transformations than the plantation soil due to the combination of multiple species and layers and, thus, stimulation of microbial activity and alteration of C and N pool sizes in favor of the N transformations by soil microbes. The net rate of N and 15N transformation demonstrated differences in N dynamic related to the variation in tree species between the two ecosystems. The change of land use and trees species had significant impacts on soil nutrients and N cycling processes. The plantation had larger losses of N than the NF. The NO3 ––N and 15NO3 ––N dominated in the mineral N and 15N pools in both forest ecosystems. Native forest soil had strong N dynamic compared with the plantation soil. Composition of multiple tree species with different ecological niches in the plantation could promote the soil ecosystem sustainability. The 15N isotope dilution technique in the field can be quite useful for studying in situ mineral 15N transformations and fate to further understand actual N dynamics in natural forest soils.

This study was carried out to compare the ecological function of exotic pine (Pinus radiata—Pr) and native pine (Pinus tabulaeformis—Pt) in terms of litter decomposition and its related N dynamics and to evaluate if the presence of broad-leaved tree species (Cercidiphyllum japonicum—Cj) or shrub species (Ostryopsis davidiana—Od) litter would promote the decomposition of pine needles and N cycling. Mass remaining, N release of the four single-species litters and mixed-species (Pt + Cj; Pr + Cj; Pt + Od; Pr + Od) litters and soil N dynamics were measured at microcosm scale during an 84-day incubation period. The Pt and Pr litter, with poorer substrate quality, indicated slower decomposition rates than did the Cj and Od litter. Due to their high C/N ratios, the N mass of Pt and Pr litter continuously increased during the early stage of decomposition, which showed that Pt and Pr litter immobilized exogenous N by microbes. No significant differences of soil inorganic, dissolved organic and microbial biomass N were found between the Pt and Pr microcosm at each sampling. The results showed that the exotic Pr performed similar ecological function to the native Pt in terms of litter decomposition and N dynamics during the early stage. The presence of Cj or Od litter increased the decomposition rates of pine needle litter and also dramatically increased soil N availability. So it is feasible for plantation managers to consider the use of Cj as an ameliorative species or to retain Od in pine plantations to promote the decomposition of pine litter and increase nutrient circulation. The results also suggested that different species litters induced different soil dissolved organic nitrogen (DON). As a major soluble N pool in soil, DON developed a different changing tendency over time compared with inorganic N, and should be included into soil N dynamic under the condition of our study.

The rhizome, stem and leaf aqueous extracts of ginger were assayed at 10, 20, 40, and 80 g l−1 for their effects on seed germination and early seedling growth of soybean and chive. All aqueous extracts at all concentrations inhibited seed germination, seedling growth, water uptake and lipase activity of soybean and chive compared with the control, and the degree of inhibition increased with the incremental extracts concentration. The degree of toxicity of different ginger plant parts can be classified in order of decreasing inhibition as stem > leaf > rhizome. The results of this study suggest that rhizome, stem and leaf of ginger contain water-soluble allelochemicals which could inhibit seed germination and seedling growth of soybean and chive. The rhizome is the main harvested part of ginger. The residue (mainly stems and leaves) of the ginger plant should be removed from the field so as to diminish its inhibitory effect. Further work is needed to specify and verify the allelochemicals produced by this plant. The results of this study suggest that ginger allelochemicals are heterotoxic, and thus intercropping should not be practiced using ginger.

Nitrate (NO 3 - -N) and ammonium (NH 4 + -N) fertilizers are the main forms of chemical inorganic nitrogen fertilizers that are widely used in agro-ecosystem for high yield. However, the responses of soil nematode food web to different forms and rates of inorganic nitrogen fertilizers are not well understood. The objective of this study was to determine the responses of soil nematode food web to the applications of inorganic nitrogen fertilizers in a continuous cucumber ( Cucumis sativus L.) cropping system. Nitrate (NaNO 3 ) and ammonium (NH 4 HCO 3 ) fertilizers were applied to cucumber plants at the nitrogen (N) rate of 0, 67.5, 135.0 and 202.5 kg N hm - 2 before planting. It was conducted in a randomized complete block design with 4 replications at Huaizi village, Leshan district, Sichuan province, Southwestern China. The effects were analyzed at the stages of seedling, blooming and fruiting, respectively. The results indicated that the numbers of nematodes were significantly higher in soils with the addition of 67.5 kg N hm -2 than the control at the seedling and blooming stages. Nematode number strongly increased at the seedling stage and decreased at the blooming and fruiting stages in nitrate-treated soils compared to the ammonium-treated. The percentage of herbivores to total nematodes significantly decreased while that of bacterivores increased with a fertilizer rate less than 135 kg N hm - 2 at the seedling and fruiting stages. Nitrate significantly reduced the percentage of herbivores, and increased that of bacterivores to total nematodes by comparison with ammonium at the blooming and fruiting stages. The application of nitrate significantly increased nematode diversity and evenness, and decreased dominance at the blooming stage relative to ammonium. Nitrate significantly decreased the values of channel index at the blooming stage and maturity index at the seedling stage in comparison with ammonium, respectively. Enrichment index and structural index strongly increased at the seedling stage, and decreased at the blooming and fruiting stages under the treatment of nitrate relative to ammonium. The results suggested responses of nematode food web dependent on the rates and forms of inorganic nitrogen fertilizers and stages of cucumber growth.