Department of Health and Environmental Sciences

Department of Health and Environmental Sciences
Emerging and Interdisciplinary Science Building (ES)
Xi'an Jiaotong-Liverpool University
111 Ren'ai Road Suzhou Dushu Lake Science and Education Innovation District , Suzhou Industrial Park
Suzhou,Jiangsu Province,P. R. China,215123
1. Clinical Validity and Reliability of the Malay Language Translations of Gastroesophageal Reflux Disease Questionnaire and Quality of Life in Reflux and Dyspepsia Questionnaire in a Primary Care Setting

Author:Vadivelu, S;Ma, ZF;Ong, EW;Hassan, N;Hassan, NFHN;Aziz, SHSA;Kueh, YC;Lee, YY


Abstract:Background: Gastroesophageal Reflux Disease Questionnaire (GERDQ) and Quality of Life in Reflux and Dyspepsia Questionnaire (QOLRAD) are reliable tools for evaluation of GERD. Aim: We aimed to test validity and reliability of Malay language translations of GERDQ and QOLRAD in a primary care setting. Methods: The questionnaires were first translated into the Malay language (GERDQ-M and QOLRAD-M). Patients from primary care clinics with suspected GERD were recruited to complete GERDQ-M, QOLRAD-M, and Malay-translated 36-item short-form health survey (SF-36 or SF36-M), and underwent endoscopy and 24-h pH-impedance test. Results: A total of 104 (mean age 47.1 years, women 51.9%%) participants were enrolled. The sensitivity and specificity for GERDQ-M cut-off score >= 8 were 90.2 and 77.4%%, respectively. Based on this cut-off score, 54.7%% had a high probability of GERD diagnosis. GERD-M score >= 8 vs. <8 was associated with erosive esophagitis (p < 0.001), hiatus hernia (p = 0.03), greater DeMeester score (p = 0.001), and Zerbib scores for acid refluxes (p < 0.001) but not non-acid refluxes (p = 0.1). Mean total scores of QOLRAD-M and SF-36-M were correlated (r = 0.74, p < 0.001). GERDQ-M = 8, erosive esophagitis, and DeMeester >= 14.72 were associated with impaired QOLRAD-M in all domains (all p < 0.02) but this was not seen with SF-36. Conclusions: GERDQ-M and QOLRAD-M are valid and reliable tools applicable in a primary care setting. (C) 2018 S. Karger AG, Basel
2. Treatment for HIV prevention study in southwestern areas of China

Author:Chen, HH;Yang, XY;Zhu, QY;Wu, XH;Chen, L;Lu, HX;Luo, LH;Lan, GH;Ge, XM;Tang, ZZ;Shen, ZY;Pan, SW;Xing, H;Ruan, YH;Shao, YM;Yang, WM


Abstract:Background: China has ambitious to achieve significant reductions in HIV transmission and HIV-related mortality by adopting the World Health Organization's "Treat All" approach. Such a prevention strategy is needed future study on regional scale. Methods: An observational cohort study of HIV epidemiology and treatment databases was used to study the effectiveness of antiretroviral therapy on the transmission of HIV in serodiscordant couples in Guangxi of China. Results: A total of 7713 couples were entered into the cohort study analysis which included 1885 couples in the treatment-naive cohort and 5828 couples in the treated cohort. During the follow-up of 18985.29 person-years from 2003 to 2014, the average incidence of HIV was 2.4 per 100 person-years (95%% CI 2.1-2.6). HIV seroincidence rate was significantly higher among the treatment naive group (4.2 per 100 person-years, 3.7-4.8) compared with the on treatment group (1.6 per 100 person-years, 1.3-1.8). An overall 45%% reduction in risk of HIV transmission among serodiscordant couple was associated with ART treatment (adjusted Hazard Ratio [HR] 0.55, 95%% Confidence Interval [CI] 0.44-0.69). Treatment prevention had significantly effectiveness for most baseline characteristics of index partners, such as for male, female, age above 25 years, education below high school, farmer, infected by heterosexual intercourse. Conclusion: Treatment-as-prevention can be implemented in the real-world on a national or regional scale, but ART adherence and comprehensive harm reduction while implementing this strategy require further study. (C) 2018 The Authors. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.
3. The effects of the bioanode on the microbial community and element profile in paddy soil

Author:Williamson, G;Chen, Z


Abstract:In paddy soil the reductive dissolution of iron oxide and the availability of organic matter plays an important role in arsenic release under anaerobic conditions. Microbial fuel cells have been shown to reduce organic matter (OM) content and the rate in which this occurs strongly relate to the external resistance applied. In this study we investigated the effects of bioanode operating at different external resistance on the paddy soil microbial community and iron and arsenic concentration. The results show that MFC can be used to reduce soil pore water iron and arsenic concentration and the extent in which this occurs depend on the external resistance applied. The MFC is able to mitigate arsenic release by decreasing organic matter availability. Furthermore, our finding shows that external resistance had a significant influence on the bacterial community composition that develop on the bioanode however only had minimal effect on the community of the bulk soil. These findings suggest that the sMFC can influence the iron and arsenic concentration by reducing OM content and the microbial community that develop in the bioanode vicinity.
4. Macroinvertebrate drift-benthos trends in a regulated river

Author:Tonkin, JD;Death, RG


Abstract:Downstream drift plays a fundamental role in the spatial distribution and community structure of lotic macroinvertebrates. We sampled both benthic and drifting macroinvertebrates at 15 sites, in three sections of river with varying flow alteration along the Tongariro River, New Zealand. Our objectives were to examine whether (i) benthic and drift density were linearly related throughout the river, (ii) the presence of dams affected the propensity of macroinvertebrates to drift, and (iii) drift propensity was related to benthic periphyton biomass or natural longitudinal patterns down the river. More taxa were collected from the drift than the benthos, although drift and benthic samples were generally taxonomically similar, despite some structural differences. Nonetheless, differences were evident between the major groups when assessing density and relative abundance links between the benthos and drift. The presence of dams did not affect the propensity of macroinvertebrates to drift on the whole, nor was propensity affected by periphyton biomass or distance from source. These results suggest that although altered periphyton biomass in downstream sections in the Tongariro River is altering the composition of benthic and drifting macroinvertebrates, drift propensity is unaffected. However, some deviations from linear relationships between benthic and drift density are evident suggesting these links may be taxon specific.
5. Topical treatments and photodynamic therapy for actinic keratosis of the face and scalp

Author:Foley,Kelly;Gupta,Aditya K.;Martin,George;Tweed,John A.;Villanueva,Elmer;Carviel,Jessie

Source:Cochrane Database of Systematic Reviews,2019,Vol.2019

Abstract:This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of topical interventions and photodynamic therapy as monotherapy or combination therapy for treatment of actinic keratoses on the face and scalp (which includes lip, face, and scalp) of immunocompetent (i.e. normal immune response) adults.
6. Light attenuation - a more effective basis for the management of fine suspended sediment than mass concentration?

Author:Davies-Colley, RJ;Ballantine, DJ;Elliott, SH;Swales, A;Hughes, AO;Gall, MP


Abstract:Fine sediment continues to be a major diffuse pollution concern with its multiple effects on aquatic ecosystems. Mass concentrations (and loads) of fine sediment are usually measured and modelled, apparently with the assumption that environmental effects of sediment are predictable from mass concentrations. However, some severe impacts of fine sediment may not correlate well with mass concentration, notably those related to light attenuation by suspended particles. Light attenuation per unit mass concentration of suspended particulate matter in waters varies widely with particle size, shape and composition. Data for suspended sediment concentration, turbidity and visual clarity (which is inversely proportional to light beam attenuation) from 77 diverse New Zealand rivers provide valuable insights into the mutual relationships of these quantities. Our analysis of these relationships, both across multiple rivers and within individual rivers, supports the proposition that light attenuation by fine sediment is a more generally meaningful basis for environmental management than sediment mass. Furthermore, optical measurements are considerably more practical, being much cheaper (by about four-fold) to measure than mass concentrations, and amenable to continuous measurement. Mass concentration can be estimated with sufficient precision for many purposes from optical surrogates locally calibrated for particular rivers.
7. The truth is in the detail: predators attack aposematic prey with less aggression than other prey types

Author:Yamazaki, Y;Pagani-Nunez, E;Sota, T;Barnett, CRA


Abstract:Aposematic organisms are often unprofitable to predators (e.g. because of defensive chemicals) which they advertise with a conspicuous signal (e.g. bright and conspicuous colour signals). Aposematism is thought to reduce predation of prey because the colour signal increases the ability of predators to learn, recognize and remember the prey's defensive properties. The efficacy of aposematism has been extensively documented in laboratory studies, although its benefits seem to be harder to demonstrate in the field. In this study, we compared the levels of partial and overall predation among four prey types (undefended and cryptic, undefended and warning coloured, defended and cryptic, and aposematic prey). Overall, predation of warning coloured and defended (aposematic) prey was lower than the predation for cryptic and undefended prey; however, it was the same as predation of cryptic and defended prey. Moreover, aposematic prey had higher levels of partial predation (where prey was not wholly consumed by the predator) and lower attack intensities. This suggests that prey were being taste sampled, but also might be better able to survive attacks. Therefore, the benefits of aposematism may lie not only in reducing outright predation, but also in altering a predator's post-attack behaviour, thus leading to greater escape opportunities and post-attack survival of prey. These results reinforce the importance of examining predation in more detail rather than simply examining attack rates.
8. Six-year removal of co-dominant grasses alleviated competitive pressure on subdominant grasses but dominant shrub removal had neutral effects in a subalpine ecosystem

Author:Li,Wenjin;Knops,Johannes M.H.;Png,G. Kenny;Yan,Xi;Dong,Huan;Li,Jinhua;Zhou,Huakun;Sierra,Rubén Díaz

Source:Global Ecology and Conservation,2020,Vol.23

Abstract:The ‘stress-gradient hypothesis’ predicts increasing facilitative interactions with increasing environmental stress, but it remains unclear if the prevailing type of interaction (i.e. facilitative or competitive) between dominant and subordinate plant species occurring in harsh environments is dependent on the plant functional type. In addition, most plant-species removal experiments in grasslands are short-term (1–2 years), which may imprecisely reflect transient effects arising from methodological limitations. We conducted a dominant species removal experiment in a subalpine ecosystem, containing a mosaic of grass-dominated and shrub-dominated community patches, both of which are common in the subalpine zone of the Qinghai-Tibetan Plateau. We examined the direction and magnitude of the effects of three co-dominant grass and a dominant shrub species on subordinate species richness and biomass over a 6-year period. Removal of the dominant grass species alleviated their competitive pressure on subdominant grasses, which resulted in similar total and grass biomass detected in the final year of the study. By contrast, shrub removal showed no effects on its subordinate species biomass. Furthermore, neither the removal of the dominant shrubs nor the grasses altered their respective subordinate species richness. Thus, in subalpine ecosystems that experience harsh environmental conditions, our results showed that the direction of interactive effects of dominant plant species on subordinate species may be dependent on the plant functional type and are not necessarily facilitative. Furthermore, we showed that longer-term plant-removal experiment observations may be required to better determine the effects of species removal for this subalpine and other montane ecosystem(s).
9. Nitrogen addition increases sexual reproduction and improves seedling growth in the perennial rhizomatous grass Leymus chinensis

Author:Gao, S;Wang, JF;Knops, JMH;Wang, J

Source:BMC PLANT BIOLOGY,2020,Vol.20

Abstract:Background: The Eurasian steppe is an important vegetation type characterized by cold, arid and nitrogen poor conditions. At the Eastern edge, including in the Songnen grassland, the vegetation is dominated by Leymus chinensis (henceforth L. chinensis) and is increasing threatened by elevated anthropogenic nitrogen deposition. L. chinensis is a perennial grass that mainly reproduces vegetatively and its sexual reproduction is limited. However, sexual reproduction plays an important role influencing colonization after large disturbances. To develop an understanding of how elevated nitrogen deposition changes the plant community structure and functioning we need a better understanding how sexual reproduction of L. chinensis changes with nitrogen enrichment. Here we report on a field experiment where we added 10 g N m(-2) yr(-1) and examined changes in seed traits, seed germination and early seedling growth. Results: Nitrogen addition increased seed production by 79%%, contributing to this seed increases were a 28%% increase in flowering plant density, a 40%% increase in seed number per plant and a 11%% increase in seed weight. Seed size increased with a 42%% increase in large seeds and a 49%% decrease in the smallest seed size category. Seed germination success improved by 10%% for small seeds and 18%% for large seeds. Combined, the increased in seed production and improved seed quality doubled the potential seed germination. Subsequent seedling above and below-ground biomass also significantly increased. Conclusions: All aspects of L. chinensis sexual reproduction increased with nitrogen addition. Thus, L. chinensis competitive ability may increase when atmospheric nitrogen deposition increases, which may further reduce overall plant diversity in the low diversity Songnen grasslands.
10. Supernatural Explanatory Models of Health and Illness and HIV Antiretroviral Therapy Use Among Young Men Who Have Sex with Men in China

Author:Pan, SW;Smith, MK;Carpiano, RM;Fu, HY;Ong, JJ;Huang, WT;Tang, WM;Tucker, JD


Abstract:Background In China, men who have sex with men (MSM) shoulder a disproportionate HIV burden. Early initiation and adherence to HIV antiretroviral therapy (ART) will be critical to reversing the HIV epidemic in China, but ART usage remains suboptimal among MSM diagnosed with HIV. One understudied but potentially important factor underpinning suboptimal ART usage is personal belief in supernatural explanatory models of health and illness (supernatural explanatory models). This study examines associations between beliefs in supernatural explanatory models and ART usage among MSM in China. Method In 2017, an online survey was distributed nationwide throughout China by gay community-based organizations. Eligible study participants were self-identified MSM between 16 and 30 years old who had tested positive for HIV and who had seen a doctor in the last 2 years. Beliefs in supernatural explanatory models were measured using a three-item scale developed specifically for the Chinese population (range, 3-15). Results Of 73 participants, the majority were currently using ART (83.6%%) and 42.5%% expressed some endorsement of belief in supernatural explanatory models. However, among 21 participants with the strongest belief in supernatural explanatory models, prevalence of current ART usage was 61.9%%. Stronger belief in supernatural explanatory models was significantly associated with lower likelihood of current ART usage (adjusted odds ratio = 0.52; 95%% confidence interval = 0.13-0.75). Conclusion Belief in supernatural explanatory models may be a powerful predictor of ART usage among MSM living with HIV in China. Further studies are needed to corroborate these findings and elucidate mechanisms of association.
11. Elevated serum uric acid, hyperuricaemia and dietary patterns among adolescents in mainland China

Author:Zhou, H;Ma, ZF;Lu, YM;Du, YY;Shao, J;Wang, LY;Wu, Q;Pan, BY;Zhu, WX;Zhao, QH;Wei, H


Abstract:Background: Elevated serum uric acid concentrations have been associated with metabolic syndrome. However, only limited information is available on the prevalence of hyperuricaemia in adolescents. Therefore, the aim of our cross-sectional study was to study the prevalence of hyperuricaemia and dietary patterns in adolescents aged 13-16 years living in Yangzhou, China. Methods: Adolescents were asked to complete a 20-item food frequency questionnaire (FFQ) and provide an overnight fasting finger-prick sample. Principal component analysis (PCA) with varimax rotation was used to derive the dietary patterns that might be associated with high uric acid concentrations. Results: A total of 1070 adolescents were recruited. Of these, 53.6%% (n = 574) were females, and 58.5%% (n = 625) were within the normal body mass index (BMI) range. The males had a significantly higher serving size and frequency in their weekly food consumption, including meat, poultry, Chinese cereal staple foods and Western-style fast foods, than the females (all p < 0.02). The overall mean serum uric acid concentration and prevalence of hyperuricaemia were 368.6 +/- 114.5 mu mol/L and 37.9%%, respectively. The prevalence of hyperuricaemia was 4.633 times greater among the participants who were overweight and obese than among those who were underweight. On the other hand, the prevalence of hyperuricaemia was 0.694 times lower among the participants who had normal weight than those who were underweight. Conclusions: The prevalence of hyperuricaemia was relatively high in Chinese adolescents. The prevention of hyperuricaemia measures should be strengthened in adolescents to effectively control for obesity and gout, which tend to persist into adulthood.
12. Soil net nitrogen transformation rates are co-determined by multiple factors during the landscape evolution in Horqin Sandy Land

Author:Lv, P;Sun, SS;Medina-Roldan, E;Zhao, SL;Hu, Y;Guo, AX;Zuo, XA


Abstract:Vegetation restoration affects soil N cycling, which in turn strongly affects ecosystem functions, such as plant productivity and N availability. The soil N availability is a major limiting factor for restoring vegetation in semiarid grasslands and affects landscape evolution. However, few studies have focused on how landscape evolution caused by vegetation restoration affects soil N availability and transformation in semiarid sandy grasslands. Here, we conducted a 5-year field experiment from 2015 to 2019 to evaluate the growth season (May-August) changes in soil inorganic N pools and net N transformation rates along a landscape evolution gradient caused by vegetation restoration: mobile dunes, semi-fixed dunes, fixed dunes, and dune grasslands. We examined the relationship between climate factors, vegetation characteristics, soil properties, and soil net N transformation rates in different landscape types through multivariate analyses. The landscape type, sampling time, interannual variation, and their interactive effects significantly affected the soil inorganic N pool and net N transformation rate. Soil nitrate N concentration accounted for 68%% of the total inorganic N, and soil nitrification dominated the soil N transformation during landscape evolution. Redundancy analysis revealed that the changes in net N nitrification and mineralization rates during the growing season were closely correlated with climate factors, vegetation characteristics, and soil properties. Variation partitioning analysis showed that the soil net N transformation rate during the growing season was mainly affected by soil properties, whereas soil net N transformation in August for all years was mainly affected by climate factors. These results suggest that soil N availability and transformation during landscape evolution caused by vegetation restoration were co-determined by climatic factors, vegetation characteristics, and soil properties. Therefore, long-term field monitoring should be considered to improve our exploration of soil N transformation changes and their underlying mechanisms in semiarid grassland ecosystems.
13. Bifidobacterium infantis M-63 improves mental health in victims with irritable bowel syndrome developed after a major flood disaster

Author:Ma, ZF;Yusof, N;Hamid, N;Lawenko, RM;Mohammad, WMZW;Liong, MT;Sugahara, H;Odamaki, T;Xiao, J;Lee, YY


Abstract:Individuals in a community who developed irritable bowel syndrome (IBS) after major floods have significant mental health impairment. We aimed to determine if Bifidobacterium infantis M-63 was effective in improving symptoms, psychology and quality of life measures in flood-affected individuals with IBS and if the improvement was mediated by gut microbiota changes. Design was non-randomised, open-label, controlled before-and-after. Of 53 participants, 20 with IBS were given B. infantis M-63 (1x10(9) cfu/sachet/day) for three months and 33 were controls. IBS symptom severity scale, hospital anxiety and depression scale, SF-36 Questionnaire, hydrogen breath testing for small intestinal bacterial overgrowth and stools for 16S rRNA metagenomic analysis were performed before and after intervention. 11 of 20 who were given probiotics (M-63) and 20 of 33 controls completed study as per-protocol. Mental well-being was improved with M-63 vs controls for full analysis (P=0.03) and per-protocol (P=0.01) populations. Within-group differences were observed for anxiety and bodily pain (both P=0.04) in the M-63 per-protocol population. Lower ratio of Firmicutes/Bacteroidetes was observed with M-63 vs controls (P=0.01) and the lower ratio was correlated with higher post-intervention mental score (P=0.04). B. infantis M-63 is probably effective in improving mental health of victims who developed IBS after floods and this is maybe due to restoration of microbial balance and the gut-brain axis. However, our conclusion must be interpreted within the context of limited sample size.
14. Plant phenotypic functional composition effects on soil processes in a semiarid grassland

Author:Medina-Roldan, E;Huber-Sannwald, E;Arredondo, JT


Abstract:Our knowledge of plant functional group effects on ecosystem processes is relatively well established, but we know much less on how changes in plant phenotypic composition affect ecosystem functioning (i.e., phenotypic functional composition). Understanding phenotypic functional composition (PFC) is relevant in plant communities strongly dominated by a few keystone species, since alteration of phenotypic composition of these species might be a mechanisms by which land management practices such as grazing impact on ecosystem functioning. Here, we report results from a field experiment where we manipulated PFC of Bouteloua gracilis (Kunth) Lag. ex Griffiths, a keystone species in the semiarid shortgrass steppe. B. gracilis' PFC was altered by using plant genetic lines which expressed consistently either high or low leaf tissue lignin content (LC), a plant trait known to affect soil biogeochemical processes. High-LC lines came from an area subjected to low grazing intensities, whereas low-LC lines came from an area historically overgrazed. Additionally, those plant genetic lines expressing high LC also expressed high dry matter content and vice versa. We established experimental plots with High (only high-LC plants), Low (only low-LC plants), and mixed (both high- and low- LC plants, BHL) LC genetic lines; and measured selected soil processes after the application of a small water pulse. We hypothesised that those soil processes related to microbial activity and nitrogen cycling would be higher in Low plots in comparison with High and BHL plots. Phenotypic functional composition did not affect most of our soil processes including ammonium and nitrate concentrations (inorganic N), microbial activity, potential ammonium mineralization, and microbial profiles of substrate utilization). Nonetheless, we observed a general response to the water pulse so that soil inorganic N increased, but soil water content and soil microbial activity decreased 48 h after the pulse application. This general response suggests that fractions of the soil microbial community with different soil moisture optima mineralise N-rich substrates. Overall, lack of response to plant phenotypic functional composition suggests that grazing effects on soil biogeochemical processes in the shortgrass steppe are not directly mediated through how grazing affects the phenotypic functional composition of B. gracilis. (c) 2013 Elsevier Ltd. All rights reserved.
15. High Baseline CD4 Counts and Antiretroviral Therapy Cessation

Author:Pan, SW;Shen, ZY;Xing, H;Ruan, YH;Shao, YM


16. Management of COPD in Anhui Province: compliance with GOLD guidelines

Author:He, SZ;Zha, L;Li, Y;Yang, G;Zhou, Y;Villanueva, EV


17. Sulfur Redox Cycling Dependent Abiotic Ferrihydrite Reduction by a Desulfitobacterium hafniense

Author:Li, GX;Chen, XP;Wang, XN;Chen, Z;Bao, P


Abstract:Biogeochemical interactions of iron and sulfur drive their cycles in many environments, which makes understanding the mechanism of sulfur redox cycling dependent abiotic iron(III) reduction by sulfate-reducing bacteria (SRB) particularly important. Here, we present a newly isolated Desulfitobacterium hafniense strain DH with the potential of reducing sulfate, sulfite, thiosulfate, and elemental sulfur from a paddy soil. Strain DH cannot enzymatically reduce ferrihydrite, but it can abiotically reduce ferrihydrite through extracellular electron transfer with biogenic sulfide or other sulfur compounds acting as electron shuttles. Sulfite, elemental sulfur, and thiosulfate, the oxidation products of sulfide, complete the sulfur cycle between ferrihydrite and strain DH. The presence of strain DH at the ferrihydrite surface results in mineral dissolution and secondary mineralization. Proteomic analysis revealed that the expression level of sulfur reduction functional protein DsrC and a thiosulfate reductase in the sulfide/ferrihydrite amendment group was 1.79 and 1.99 times higher, respectively, than in the sulfide-only amendment setup. On the other hand, the protein expression level of DsrAB showed no significant variation. A number of carbon metabolism enzymes, including succinate dehydrogenase (2.46 fold), fumarate reductase (2.64 fold), acetyl-coenzyme A synthetase (2.64 fold) and phosphoenolpyruvate synthase (3.4 fold), were up-regulated significantly due to the stimulation of released ferrous ion that was generated during the sulfur redox cycling dependent abiotic ferrihydrite reduction process. This result confirms the important role of DsrC and thiosulfate reductase in sulfur redox cycling dependent abiotic ferrihydrite reduction. Sulfur redox cycling dependent abiotic iron oxide reduction mediated by SRB might be a widespread process in the environment.
18. Abiotic factors affect leaf litter mass loss more strongly than initial litter traits under sand burial conditions

Author:Qu, H;Zhao, XY;Wang, SK;Lian, J;Tang, X;Wang, XY;Zhang, R;Medina-Roldan, E


Abstract:Litter decomposition is an important ecosystem process and a key determinant of nutrient turnover and carbon cycling in arid and semiarid regions. Sand burial is common in arid and semiarid regions and may strongly influence litter decomposition. However, the main factors influencing litter decomposition under sand burial conditions are uncertain. We performed a litter bag experiment over 3 years to understand the effects of sand burial on litter mass loss and measured abiotic factors (light intensity, soil temperature and humidity) and initial litter traits to determine which factors most influenced litter mass losses. The leaf litters of three dominant shrubs (Artemisia halodendron, Caragana microphylla, and Salix gordejevii) in the Horqin Sandy Land of northern China were selected, and four burial depths (surface, 5 cm, 10 cm, and 20 cm) were used. The results showed that the litter from the three shrubs under the surface treatment (no burial) and at the 5 cm burial depth decomposed more rapidly than the litter that was buried at depths of 10 cm and 20 cm. This is explained because the abiotic factors on the surface and at 5 cm burial depth were conducive for the mass loss of litter. The differences in litter mass losses among the three shrubs were not significant under other burial treatments, except that A. halodendron's litter decomposed significantly faster than litter from the other two shrubs at depths of 10 cm. Species differences in litter traits were weaker than the effects of burial depths and retrieval times on litter mass loss. The stepwise regression analysis showed that light intensity and soil temperature were the most important factors influencing the mean litter mass loss of 3 years. Therefore, we concluded that relative to the initial litter traits, abiotic factors are more able to indicate the leaf litter mass loss under sand burial conditions, and abiotic factors limiting litter mass loss switch with burial depths.
19. Landscape effects on pollinator communities and pollination services in small-holder agroecosystems

Author:Zou, Y;Bianchi, FJJA;Jauker, F;Xiao, HJ;Chen, JH;Cresswell, J;Luo, SD;Huang, JK;Deng, XZ;Hou, LL;van der Werf, W


Abstract:Pollination by insects is key for the productivity of many fruit and non-graminous seed crops, but little is known about the response of pollinators to landscapes dominated by small-holder agriculture. Here we assess the relationships between landscape context, pollinator communities (density and diversity) and pollination of oilseed rape in 18 landscapes with proportions of small-holder farming ranging from 10%% to 70%% in southern China. To quantify the contribution of pollinators to oilseed rape yield, we manipulated pollinator access in a focal oilseed rape field in each landscape using open and closed cages. The pollinator communities in the focal fields were sampled using pan traps. The abundance of wild pollinators increased significantly with the proportion of cultivated land, but the diversity of the wild pollinator communities declined. The responses of pollinator abundance and diversity to cultivated land were best explained at scales of around 1000 m. The abundance of the unmanaged honey bee Apis cerana was positively associated with the proportion of cultivated land, whereas the abundance of the managed A. mellifera was not. A pollination services index (PSI) was calculated by comparing the reproductive investment in seeds between plants with or without pollinator access. PSI was positively correlated with wild pollinator abundance, but not with the abundance of honeybee species. PSI was also not significantly correlated with the area proportion of cultivated land. Our results indicate that crop dominated landscapes with numerous small fields supported an abundant, but relatively species poor bee community that delivered pollination services to oilseed rape. Conservation of (semi-)natural habitats, however, is important for maintaining the diversity of wild pollinators.
20. Wildlife trade: ban orientalism

Author:Pagani-Nunez, E


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