Comparing connection to theory in Bachelor's theses: Old research university versus new regional university college

Quality of higher education is often assumed to be linked to the size of the faculty. Therefore, this study tested the hypothesis whether Bachelor's theses in ecology at a large, old research university would have more connection to theory than those at a small, young university college. The results revealed no significant difference between the universities. One potential explanation for these results is that theory is more likely to depend on the individual supervisor who may demand a clear connection to theory in Bachelor's theses. However, in the group of theses categorized as without a clear connection to theory, there were significant differences between the two universities regarding whether students were testing/developing a method or performing a case study. At the large, well-equipped research university, Bachelor's theses were significantly more likely to be based on developing/testing methods, while those at the university college more often comprised inexpensive case studies. Further studies including more universities of contrasting sizes, across countries and disciplines, are required to test the general validity of the findings.qscienc

Impacts of urbanization on the distribution of heavy metals in soils along the Huangpu River, the drinking water source for Shanghai

We investigated the horizontal and vertical distribution of heavy metals (Hg, Pb, Zn, Cu, Cd, As, Ni, and Cr) in soils in the water source protection zone for Shanghai to study the origins of these metals, their connections with urbanization, and their potential risk posed on the ecosystem. Determination of metal concentrations in 50 topsoil samples and nine soil profiles indicated that Hg, Pb, Zn, and Cu were present in significantly higher concentrations in topsoil than in deep soil layers. The spatial distributions of Hg, Pb, Zn, and Cu and contamination hotspots for these metals in the study area were similar to those near heavy industries and urban built-up areas. Emissions from automobiles resulted in increased soil concentrations of Cu, Pb, and Zn along roadsides, while high concentrations of Hg in the soil resulted from recent atmospheric deposition. Calculation of the potential ecological risk indicated that the integrative risk of these heavy metals in most areas was low, but a few sites surrounding high density of factories showed moderate risks.National Natural Science Foundation of China (Grant No. 41401588)

Impacts of different climate change regimes and extreme climatic events on an alpine meadow community

Climate variability is expected to increase in future but there exist very few experimental studies that apply different warming regimes on plant communities over several years. We studied an alpine meadow community under three warming regimes over three years. Treatments consisted of (a) a constant level of warming with open-top chambers (ca. 1.9 °C above ambient), (b) yearly stepwise increases in warming (increases of ca. 1.0, 1.9 and 3.5 °C), and (c) pulse warming, a single first-year pulse event of warming (increase of ca. 3.5 °C). Pulse warming and stepwise warming was hypothesised to cause distinct first-year and third-year effects, respectively. We found support for both hypotheses; however, the responses varied among measurement levels (whole community, canopy, bottom layer, and plant functional groups), treatments, and time. Our study revealed complex responses of the alpine plant community to the different experimentally imposed climate warming regimes. Plant cover, height and biomass frequently responded distinctly to the constant level of warming, the stepwise increase in warming and the extreme pulse-warming event. Notably, we found that stepwise warming had an accumulating effect on biomass, the responses to the different warming regimes varied among functional groups, and the short-term perturbations had negative effect on species richness and diversityNFR grant (B-AA/BU 08424) to UM

Community and species-specific responses of plant traits to 23 years of experimental warming across subarctic tundra plant communities

To improve understanding of how global warming may affect competitive interactions among plants, information on the responses of plant functional traits across species to long-term warming is needed. Here we report the effect of 23 years of experimental warming on plant traits across four different alpine subarctic plant communities: tussock tundra, Dryas heath, dry heath and wet meadow. Open-top chambers (OTCs) were used to passively warm the vegetation by 1.5–3 °C. Changes in leaf width, leaf length and plant height of 22 vascular plant species were measured. Long-term warming significantly affected all plant traits. Overall, plant species were taller, with longer and wider leaves, compared with control plots, indicating an increase in biomass in warmed plots, with 13 species having significant increases in at least one trait and only three species having negative responses. The response varied among species and plant community in which the species was sampled, indicating community-warming interactions. Thus, plant trait responses are both species- and community-specific. Importantly, we show that there is likely to be great variation between plant species in their ability to maintain positive growth responses over the longer term, which might cause shifts in their relative competitive ability.Scopu

Short-term herbivory has long-term consequences in warmed and ambient high Arctic tundra

Source at https://doi.org/10.1088/1748-9326/aa579d. Climate change is occurring across the world, with effects varying by ecosystem and region but already occurring quickly in high-latitude and high-altitude regions. Biotic interactions are important in determining ecosystem response to such changes, but few studies have been long- term in nature, especially in the High Arctic. Mesic tundra plots on Svalbard, Norway, were subjected to grazing at two different intensities by captive Barnacle geese from 2003–2005, in a factorial design with warming by Open Top Chambers. Warming manipulations were continued through 2014, when we measured vegetation structure and composition as well as growth and reproduction of three dominant species in the mesic meadow. Significantly more dead vascular plant material was found in warmed compared to ambient plots, regardless of grazing history, but in contrast to many short-term experiments no difference in the amount of living material was found. This has strong implications for nutrient and carbon cycling and could feed back into community productivity. Dominant species showed increased flowering in warmed plots, especially in those plots where grazing had been applied. However, this added sexual reproduction did not translate to substantial shifts in vegetative cover. Forbs and rushes increased slightly in warmed plots regardless of grazing, while the dominant shrub, Salix polaris , generally declined with effects dependent on grazing, and the evergreen shrub Dryas octopetala declined with previous intensive grazing . There were no treatment effects on community diversity or evenness. Thus despite no changes in total live abundance, a typical short-term response to environmental conditions, we found pronounced changes in dead biomass indicating that tundra ecosystem processes respond to medium- to long-term changes in conditions caused by 12 seasons of summer warming. We suggest that while high arctic tundra plant communities are fairly resistant to current levels of climate warming, underlying ecosystem processes are beginning to change. In addition, even short bouts of intense herbivory can have long-term consequences for some species in these communities

Temporal variations in ambient air quality indicators in Shanghai municipality, China

© 2020, The Author(s). Official data on daily PM2.5, PM10, SO2, NO2, CO, and maximum 8-h average O3 (O3_8h) concentrations from January 2015 to December 2018 were evaluated and air pollution status and dynamics in Shanghai municipality were examined. Factors affecting air quality, including meteorological factors and socio-economic indicators, were analyzed. The main findings were that: (1) Overall air quality status in Shanghai municipality has improved and number of days meeting ‘Chinese ambient air quality standards’ (CAAQS) Grade II has increased. (2) The most frequent major pollutant in Shanghai municipality is O3 (which exceeded the standard on 110 days in 2015, 84 days in 2016, 126 days in 2017, 113 days in 2018), followed by PM2.5 (120days in 2015, 104 days in 2016, 67 days in 2017, 61 days in 2018) and NO2 (50 days in 2015, 67 days in 2016, 79 days in 2017, 63 days in 2018). (3) PM2.5 pollution in winter and O3 pollution in summer are the main air quality challenges in Shanghai municipality. (4) Statistical analysis suggested that PM2.5, PM10, SO2 and NO2 concentrations were significantly negatively associated with precipitation (Prec) and atmosphere temperature (T) (p < 0.05), while the O3 concentration was significantly positively associated with Prec and T (p < 0.05). Lower accumulation of PM, SO2, NO2, and CO and more serious O3 pollution were revealed during months with higher temperature and more precipitation in Shanghai. The correlation between the socio-economic factors and the air pollutants suggest that further rigorous measures are needed to control PM2.5 and that further studies are needed to identify O3 formation mechanisms and control strategies. The results provide scientific insights into meteorological factors and socio-economic indicators influencing air pollution in Shanghai.This study was supported by the Key Research Program of Frontier Sciences (Grant No. ZDBS-LY-7011), National Key Research and Development Program of China (2017YFF0207303; 2016YFC0503004). The online sharing of air quality data by the Shanghai Environmental Monitoring Center is gratefully acknowledged

Severe vegetation degradation associated with different disturbance types in a poorly managed urban recreation destination in Iran

Recreational activities worldwide have major impacts on the environment. This study examined the impact of different kinds of recreational activities on plant communities in a highly visited park in Mashhad, Iran. Vegetation in the park was sampled along 41 random 10-m transects with different human disturbances (trails, dirt roads, campsites) and undisturbed communities. Life form spectrum, species composition, species and phylogenetic diversity were determined for all communities. Disturbance increased the frequency of therophytes, but decreased the frequency of chamaephytes and percentage vegetated area. Recreational-mediated disturbance had variable impact on species composition, but decreased species and phylogenetic diversity compared with undisturbed areas. Roads and campsites caused the greatest damage, while trails had the smallest negative impact on vegetation. This study showed that damage to (semi-)natural park vegetation differs with recreation activity. This finding can help prioritise management activities to minimise negative impacts of recreation activities on local vegetation. The current visitor load to the urban park studied here appears too high to be sustainable over time, so better monitoring and restrictions on visitor numbers may be needed to minimise the negative impacts on park vegetation. The camping impacts can be managed by creating clusters of designated campsites to spatially concentrate the impact area. Low-impact practices should be communicated to visitors.This work was fnancially supported by Iran National Science Foundation, INSF (grant number: 98026163

Quantification of ecosystem services providing socio-economic benefits to customary owners of natural resources in Pauri, western Himalaya

Climate change has negative consequences for the biophysical environment and an observable impact on flows of ecosystem services. Considering the high relevance of ecosystem services, it is imperative to analyze the present status of ecosystem services flows, for effective planning to cope with natural and anthropogenic catastrophes. It is equally important to identify drivers of natural resource deterioration. In a study conducted among 545 randomly selected households in 91 villages along an altitudinal gradient (1801 m asl (zone C)) in Pauri District, Uttarakhand, India, a multi-disciplinary bottom-up, indicator-based approach was applied for identification and normalization of indicators pertaining to ecosystem services. The greatest reduction in ecosystem services was recorded in zone A (0.56), followed by zone B (0.46) and C (0.35). The greatest estimated deterioration was seen in supportive (0.48) and regulatory (0.47) services. The perspective provided can facilitate adaptive management of ecosystems along an altitudinal gradient in the Himalayas, e.g., the district-level quantification of ecosystem services can guide policy-makers and planners towards more efficient adaptation planning and help minimize the gap between local requirements and policy/program formulation.The authors express their gratitude to the Hemvati Nandan Bahuguna Garhwal (A Central) University, Srinagar, Uttarakhand, India, for research assisstence. The authors thank editors Brian Fath and Bronwyn Hayward, and reviewers for constructive comments that improved the paper. JMA was funded by Qatar Petroleum (QUEX-CAS-QP-RD-18/19)