pinecone/core-2020-05-10-deduplication huggingface dataset:
Competition for nutrients and light: testing advances in resource competition with a natural phytoplankton community

A key challenge in ecology is to understand how nutrients and light affect the biodiversity and community structure of phytoplankton and plant communities. According to resource competition models, ratios of limiting nutrients are major determinants of species composition. At high nutrient levels, however, species interactions may shift to competition for light, which might make nutrient ratios less relevant. The "nutrient-load hypothesis" merges these two perspectives, by extending the classic model of competition for two nutrients to include competition for light. Here, we test five key predictions of the nutrient-load hypothesis using multispecies competition experiments. A marine phytoplankton community sampled from the North Sea was inoculated in laboratory chemostats provided with different nitrogen (N) and phosphorus (P) loads to induce either single resource limitation or co-limitation of N, P, and light. Four of the five predictions were validated by the experiments. In particular, different resource limitations favored the dominance of different species. Increasing nutrient loads caused changes in phytoplankton species composition, even if the N:P ratio of the nutrient loads remained constant, by shifting the species interactions from competition for nutrients to competition for light. In all treatments, small species became dominant whereas larger species were competitively excluded, supporting the common view that small cell size provides a competitive advantage under resource-limited conditions. Contrary to expectation, all treatments led to coexistence of diatoms, cyanobacteria and green algae, resulting in a higher diversity of species than predicted by theory. Because the coexisting species comprised three phyla with different photosynthetic pigments, we speculate that niche differentiation in the light spectrum might play a role. Our results show that mechanistic resource competition models that integrate nutrient-based and light-based approaches provide an important step forward to understand and predict how changing nutrient loads affect community composition
Negligible effect of competition on coral colony growth

MD was supported by the ERC (BioTIME 250189) and the Scottish Funding Council (MASTS –HR09011). JM, AB and SC were supported by fellowships from the Australian Research Council (FT110100609, FT0990652 and DP0880544, respectively).Competition is an important determinant of assemblage structure and population regulation, often resulting in decreased growth, fecundity or survival. In corals, most studies testing for an effect of competition on demographic traits, such as growth, have been experimental and often impose very high levels of competition upon colonies. To more realistically assess the role of competition on coral traits, multispecies studies in the wild are required. Here, we use 5 yr of data that includes 11 coral species on the reef crest at Lizard Island on the Great Barrier Reef to quantify the effect of competition on growth. Additionally, we test whether species differ in their susceptibility to direct‐contact (overgrowth and digestion) and overtopping competition, and whether species from some morphological groups are more likely to compete with one another than with species from other morphological groups. We also investigate the relationships between competitive ability and three key traits: growth rate, mechanical stability and fecundity. In contrast to most previous work using field manipulations of competition, we found a negligible effect of competition on growth. Acropora species consistently won overtopping encounters but lost in direct‐contact encounters, and these results were consistent among the four Acropora morphological groups. In contrast, the massive Goniastrea spp. were poor at overtopping but generally won direct‐contact encounters. Only tabular colonies were disproportionally more likely to compete against one another than with other morphologies. This propensity increases intraspecific relative to interspecific competition, a phenomenon that can promote coexistence when it is present among dominant competitors. Good competitors grew more quickly and had higher fecundity but were less mechanically stable, implying a tradeoff between performance during disturbance vs. performance in the absence of disturbance. We conclude that competition among adults is less likely to influence community dynamics than previously thought. If competition does have an effect, it is more likely to occur at life‐stages other than adults.Publisher PDFPeer reviewe
Climate change alterations to ecosystem dominance: how might sponge-dominated reefs function?

Anthropogenic stressors are impacting ecological systems across the world. Of particular concern are the recent rapid changes occurring in coral reef systems. With ongoing degradation from both local and global stressors, future reefs are likely to function differently to current coral-dominated ecosystems. Determining key attributes of future reef states is critical to reliably predict outcomes for ecosystem service provision. Here we explore the impacts of changing sponge dominance on coral reefs. Qualitative modelling of reef futures suggests that changing sponge dominance due to increased sponge abundance will have different outcomes for other trophic levels compared with increased sponge dominance as a result of declining coral abundance. By exploring uncertainty in the model outcomes we identify the need to: i) quantify changes in carbon flow through sponges, ii) determine the importance of food limitation for sponges, iii) assess the ubiquity of the recently described \u27sponge loop\u27, iv) determine the competitive relationships between sponges and other benthic taxa, particularly algae, and v) understand how changing dominance of other organisms alters trophic pathways and energy flows through ecosystems. Addressing these knowledge gaps will facilitate development of more complex models that assess functional attributes of sponge-dominated reef ecosystems. This article is protected by copyright. All rights reserved
Landscape heterogeneity strengthens the relationship between β-diversity and ecosystem function.

Consensus has emerged in the literature that increased biodiversity enhances the capacity of ecosystems to perform multiple functions. However, most biodiversity/ecosystem function studies focus on a single ecosystem, or on landscapes of homogenous ecosystems. Here, we investigate how increased landscape-level environmental dissimilarity may affect the relationship between different metrics of diversity (α, β, or γ) and ecosystem function. We produced a suite of simulated landscapes, each of which contained four experimental outdoor aquatic mesocosms. Differences in temperature and nutrient conditions of the mesocosms allowed us to simulate landscapes containing a range of within-landscape environmental heterogeneities. We found that the variation in ecosystem functions was primarily controlled by environmental conditions, with diversity metrics accounting for a smaller (but significant) amount of variation in function. When landscapes were more homogeneous, α, β, and γ diversity was not associated with differences in primary production, and only γ was associated with changes in decomposition. In these homogeneous landscapes, differences in these two ecosystem functions were most strongly related to nutrient and temperature conditions in the ecosystems. However, as landscape-level environmental dissimilarity increased, the relationship between α, β, or γ and ecosystem functions strengthened, with β being a greater predictor of variation in decomposition at the highest levels of environmental dissimilarity than α or γ. We propose that when all ecosystems in a landscape have similar environmental conditions, species sorting is likely to generate a single community composition that is well suited to those environmental conditions, β is low, and the efficiency of diversity-ecosystem function couplings is similar across communities. Under this low β, the effect of abiotic conditions on ecosystem function will be most apparent. However, when environmental conditions vary among ecosystems, species sorting pressures are different among ecosystems, producing different communities among locations in a landscape. These conditions lead to stronger relationships between β and the magnitude of ecosystem functions. Our results illustrate that abiotic conditions and the homogeneity of communities influence ecosystem function expressed at the landscape scale
Community-wide consequences of sexual dimorphism: evidence from nectar microbes in dioecious plants

花の性別により微生物が異なることを発見 --雄花と雌花が蜜や昆虫を介して細菌や酵母に与える効果を検証--. 京都大学プレスリリース. 2018-09-18.Intraspecific trait variation is receiving renewed interest as a factor affecting the structure of multi‐species communities within and across trophic levels. One pervasive form of intraspecific trait variation is sexual dimorphism in animals and plants, which might exert large effects particularly on the communities of host‐associated organisms, but the extent of these effects is not well understood. We investigated whether host‐associated microbial communities developed differently in the floral nectar of female and male individuals of the dioecious shrubs, Eurya emarginata and E. japonica. We found that nectar‐colonizing microbes such as bacteria and fungi were more than twice as prevalent and, overall, more than 10 times as abundant in male flowers as in female flowers. Microbial species composition also differed between flower sexes. To examine potential mechanisms behind these differences, we manipulated the frequency of flower visitation by animals and the order of arrival of microbial species to nectar. Animal visitation frequency affected microbial communities more greatly in male flowers, while arrival order affected them more in female flowers. These sex‐specific effects appeared attributable to differences in how animals and microbes altered the chemical characteristics of nectar that limited microbial growth. Taken together, our results provide evidence that sexual dimorphism can have large effects on the structure of host‐associated communities
Favorable effect of mycorrhizae on biomass production efficiency exceeds their carbon cost in a fertilization experiment

Biomass production efficiency (BPE), the ratio of biomass production to photosynthesis, varies greatly among ecosystems and typically increases with increasing nutrient availability. Reduced carbon partitioning to mycorrhizal fungi (i.e., per unit photosynthesis) is the hypothesized underlying mechanism, as mycorrhizal abundance and plant dependence on these symbionts typically decrease with increasing nutrient availability. In a mesocosm experiment with Zea mays, we investigated the effect of nitrogen (N) and phosphorus (P) addition and of mycorrhizal inoculation on BPE. Photosynthesis and respiration were measured at mesocosm scale and at leaf scale. The growth of arbuscular mycorrhizal fungi (AMF) was assessed with ingrowth bags while also making use of the difference in δ13 C between C4 plants and C3 soil. Mesocosms without AMF, that is, with pasteurized soil, were used to further explore the role of AMF. Plant growth, photosynthesis, and BPE were positively affected by P, but not by N addition. AMF biomass also was slightly higher under P addition, but carbon partitioning to AMF was significantly lower than without P addition. Interestingly, in the absence of AMF, plants that did not receive P died prematurely. Our study confirmed the hypothesis that BPE increases with increasing nutrient availability, and that carbon partitioning to AMF plays a key role in this nutrient effect. The comparison of inoculated vs. pasteurized mesocosms further suggested a lower carbon cost of nutrient uptake via AMF than via other mechanisms under nutrient rich conditions
Eating at high elevation: An herbivorous beetle from alpine rock outcrops relies on ammonia-absorbing lichens

The flightless endemic New Zealand beetle, Protodendrophagus antipodes Thomas 2003 (Coleoptera: Silvanidae: Brontinae: Brontini; Fig. 1a, b), is unique among its tribe of 12 globally distributed genera in exchanging the forest for an alpine existence. Until recently, P. antipodes was thought to be rare, known only from a handful of specimens from above the tree line in mountains in the northern part of New Zealand's South Island. Following the discovery of the beetle's favored habitat of alpine rock outcrop crevices (Fig. 1c), they have been found by J. Marris at 19 of 24 localities examined, along much of the 700 km length of the South Island mountains and from 1,500 m to over 2,000 m elevation
The bioelements, the elementome, and the biogeochemical niche

Every living creature on Earth is made of atoms of the various bioelements that are harnessed in the construction of molecules, tissues, organisms, and communities, as we know them. Organisms need these bioelements in specific quantities and proportions to survive and grow. Distinct species have different functions and life strategies, and have therefore developed distinct structures and adopted a certain combination of metabolic and physiological processes. Each species is thus also expected to have different requirements for each bioelement. We therefore propose that a "biogeochemical niche" can be associated with the classical ecological niche of each species. We show from field data examples that a biogeochemical niche is characterized by a particular elementome defined as the content of all (or at least most) bioelements. The differences in elementome among species are a function of taxonomy and phylogenetic distance, sympatry (the bioelemental compositions should differ more among coexisting than among non-coexisting species to avoid competitive pressure), and homeostasis with a continuum between high homeostasis/low plasticity and low homeostasis/high plasticity. This proposed biogeochemical niche hypothesis has the advantage relative to other associated theoretical niche hypotheses that it can be easily characterized by actual quantification of a measurable trait: the elementome of a given organism or a community, being potentially applicable across taxa and habitats. The changes in bioelemental availability can determine genotypic selection and therefore have a feedback on ecosystem function and organization, and, at the end, become another driving factor of the evolution of life and the environment
Partner support, social-cognitive variables and their role in adherence to self-monitoring of blood glucose in type 2 diabetes

In Portugal, diabetes affects 11.7% of the population, of whom about 90% have type 2
diabetes. Patients and their partners are affected and the latter have a direct impact on
patients’ adaptation to diabetes. A large proportion of patients, at diagnosis, have to
readjust their daily routines in order to integrate self-care behaviours related to diabetes.
The goal of this study was to analyse the relationship among partner support,
social-cognitive variables about self-monitoring of blood glucose (SMBG) (intentions,
attitudes, subjective norms, perceived behaviour control, action planning and coping
planning), adherence and glycaemic control in type 2 diabetes patients, diagnosed in the
past 12 months.
A total of 179 people with diabetes participated in the study. The instruments used
were: Multidimensional Diabetes Questionnaire; Revised Summary of Diabetes Self-Care
Activities Scale; and Planned Behavior Questionnaire – Self-Monitoring of Blood Glucose.
Glycaemic control was assessed by HbA1c.
The perception of positive support from partners and intention to perform SMBG
predicted adherence to SMBG. Furthermore, positive support mediated the relationship
between intention and adherence to SMBG. Positive and negative partner support were
positively associated with intention, action and coping planning and adherence to SMBG.
Good metabolic control was negatively associated with negative support.
The results show the importance of partners’ support and social-cognitive variables,
regarding self-monitoring of blood glucose, on patients’ adherenceFundação para a Ciência e Tecnologia (FCT
Factors affecting uptake of an education and physical activity programme for newly diagnosed type 2 diabetes.

Background:\ud
Intensive lifestyle intervention involving weight reduction and moderate physical activity has been shown to help regulate, and even prevent, type 2 diabetes.\ud
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Aim:\ud
This study sought to explore factors affecting uptake of an education and physical activity programme for those diagnosed with type 2 diabetes.\ud
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Method:\ud
Focus group discussions were conducted with individuals who completed the programme and semi-structured interviews were conducted with those who declined the invitation to attend. Data were analysed using a thematic framework approach and key similarities and differences between the groups were identified.\ud
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Results:\ud
The 11 programme participants studied appeared to have received clearer messages about the severity of unmanaged diabetes, whereas the 10 non-attenders studied felt that co-morbidities posed greater risks to their health. There were major concerns among both groups about undertaking exercise, and strategies for diabetes management focused heavily on dietary modification.\ud
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Conclusion:\ud
The findings of this study suggest that fears and lack of understanding about both diabetes and exercise can act as barriers to engaging in physical activity. These findings are supported by the literature and highlight the need for more tailored programmes of lifestyle intervention for those with type 2 diabetes
The Mechanics of Virtue: Lessons on Public Participation from Implementing the Water Framework Directive in the Netherlands

Public participation is often presented as a virtue (a normative good), but the strategy comes with its own mechanical flaws. Policy debates and the literature have for a long time been dominated by this idea of public participation as a virtue, but recently the literature has become more critical, addressing the instrumental and substantive aspects of public participation. This article engages with and adds to the literature by presenting the use of public participation in implementing the European Water Framework Directive in the Netherlands. The study traces and discusses a number of mechanistic issues related to public participation
Growing Green Democracy? Barriers to Ecological Modernization in Democratizing States

Ecological modernization has established an important position in the field of environmental politics. The adoption of technocratic solutions to environmental challenges is attractive to policymakers. Ecological modernization enables such an approach, in combination with mechanisms for participation and reflexive policy development. However, there are questions regarding the applicability of the concept to political contexts differing from those in the Northern European states in which it first emerged. This paper examines the challenges associated with adopting ecological modernization in the context of democratization and draws on analysis of the development of environmental politics in Bulgaria to illustrate the difficulties identified. The findings suggest that the adoption of ecological modernization during a period of democratization may lead to the hardening of closed technocratic policy-making, limiting wider participation and preventing the development of stronger and more reflexive forms of ecological modernization
What Roles are There for Government in Voluntary Environmental Programmes?

This article seeks to understand to a greater extent why and how governments are involved in voluntary environmental programmes (VEPs). A better understanding of the role(s) of government in VEPs is of relevance because the current VEP literature considers such involvement one of the key conditions that may explain VEP performance. Building on the existing VEP literature, the article maps, describes and contrasts the roles of governments in 40 VEPs in the building sector in Australia, the Netherlands, Singapore and the United States. It finds that governments are involved in almost all of these VEPs (95 per cent) and that governments predominantly take up traditional roles (i.e. initiating and leading VEPs and monitoring and enforcing VEPs), sometimes combined with innovative roles (i.e. supporting VEPs or assembling VEPs). This, the article argues, leaves opportunities for other modes of involvement unexplored, particularly those in which governments take up only innovative roles in VEPs
The Indignados as a socio-environmental movement. Framing the crisis and democracy

This study analyzes the framing processes of the Indignados movement in Barcelona, as an exemplar of the latest wave of protests, and argues that it expresses a new ecological-economic way out of the crisis. It finds that the movement was not just a reaction to the economic crisis and austerity policies, but that it put forward a metapolitical critique of the social imaginary and (neo)liberal representative democracy. The diagnostic frames of the movement denunciate the subjugation of politics and justice to economics, and reject the logic of economism. The prognostic frames of the movement advance a vision of socio-ecological sustainability and of "real democracy", each articulated differently by a "pragmatist" and an "autonomist" faction within the movement. It argues that frames are overarching outer boundaries that accommodate different ideologies. Ideologies can nevertheless also be put into question by antagonizing frames. Furthermore, through the lens of the Indignados critique, the distinction between materialist and post-materialist values that characterizes the New Social Movement literature is criticised, as "real democracy" is connected to social and environmental justice as well as to a critique of economism and the "imperial mode of living"
Multi-level reinforcement in European climate and energy governance: mobilizing economic interests at the sub-national levels

This article explains the relatively successful performance of the European Union (EU) in climate and energy governance by two factors: (1) multi-level reinforcement and (2) the mobilization of economic interests at different levels of governance through low-carbon industrial policy. The article adds to the literature by further developing existing arguments on multi-level reinforcement in climate and energy policy. We stress the point that economic co-benefits of climate protection have been successfully mobilized at all levels of governance, including the sub-national level, in recent times. This is illustrated by examples from pioneer countries as well as laggards and waverers in terms of national climate and energy policy. While it is far from certain whether the EU will indeed deliver the needed CO2 reductions to reach its internationally agreed targets, this paper, nevertheless, highlights why the EU system of climate governance remains relatively robust in light of the various challenges it currently faces. (c) 2017 The Authors. Environmental Policy and Governance published by ERP Environment and John Wiley & Sons Lt