Insight
is our reward

Publications in Ecology by NOMIS researchers

NOMIS Researcher(s)

Published in

March 1, 2024

Most cryospheric ecosystems are energy limited. How their energetics will respond to climate change remains largely unknown. This is particularly true for glacier-fed streams, which interface with the cryosphere and initiate some of Earth’s largest river systems. Here, by studying resource stoichiometry and microbial energetics in 154 glacier-fed streams sampled by the Vanishing Glaciers project across Earth’s major mountain ranges, we show that these ecosystems and their benthic microbiome are overall carbon and phosphorus limited. Threshold elemental ratios and low carbon use efficiencies (median: 0.15) modelled from extracellular enzymatic activities corroborate resource limitation in agreement with maintenance metabolism of benthic microorganisms. Space-for-time substitution analyses suggest that glacier shrinkage will stimulate benthic primary production in glacier-fed streams, thereby relieving microbial metabolism from carbon limitation. Concomitantly, we find that increasing streamwater temperature will probably stimulate microbial growth (temperature sensitivity: 0.62 eV). Consequently, elevated microbial demands for phosphorus, but diminishing inputs from subglacial sources, may intensify phosphorus limitation as glaciers shrink. Our study thus unveils a ‘green transition’ towards autotrophy in the world’s glacier-fed streams, entailing shifts in the energetics of their microorganisms.

Research field(s)
Ecology, Environmental Sciences

NOMIS Researcher(s)

May 16, 2023

Aim: Globally distributed plant trait data are increasingly used to understand relationships between biodiversity and ecosystem processes. However, global trait databases are sparse because they are compiled from many, mostly small databases. This sparsity in both trait space completeness and geographical distribution limits the potential for both multivariate and global analyses. Thus, ‘gap-filling’ approaches are often used to impute missing trait data. Recent methods, like Bayesian hierarchical probabilistic matrix factorization (BHPMF), can impute large and sparse data sets using side information. We investigate whether BHPMF imputation leads to biases in trait space and identify aspects influencing bias to provide guidance for its usage. Innovation: We use a fully observed trait data set from which entries are randomly removed, along with extensive but sparse additional data. We use BHPMF for imputation and evaluate bias by: (1) accuracy (residuals, RMSE, trait means), (2) correlations (bi- and multivariate) and (3) taxonomic and functional clustering (valuewise, uni- and multivariate). BHPMF preserves general patterns of trait distributions but induces taxonomic clustering. Data set–external trait data had little effect on induced taxonomic clustering and stabilized trait–trait correlations. Main Conclusions: Our study extends the criteria for the evaluation of gap-filling beyond RMSE, providing insight into statistical data structure and allowing better informed use of imputed trait data, with improved practice for imputation. We expect our findings to be valuable beyond applications in plant ecology, for any study using hierarchical side information for imputation. © 2023 The Authors. Global Ecology and Biogeography published by John Wiley & Sons Ltd.

Research field(s)
Natural Sciences, Biology, Ecology

Logged and structurally degraded tropical forests are fast becoming one of the most prevalent land-use types throughout the tropics and are routinely assumed to be a net carbon sink because they experience rapid rates of tree regrowth. Yet this assumption is based on forest biomass inventories that record carbon stock recovery but fail to account for the simultaneous losses of carbon from soil and necromass. Here, we used forest plots and an eddy covariance tower to quantify and partition net ecosystem CO2 exchange in Malaysian Borneo, a region that is a hot spot for deforestation and forest degradation. Our data represent the complete carbon budget for tropical forests measured throughout a logging event and subsequent recovery and found that they constitute a substantial and persistent net carbon source. Consistent with existing literature, our study showed a significantly greater woody biomass gain across moderately and heavily logged forests compared with unlogged forests, but this was counteracted by much larger carbon losses from soil organic matter and deadwood in logged forests. We estimate an average carbon source of 1.75 ± 0.94 Mg C ha−1 yr−1 within moderately logged plots and 5.23 ± 1.23 Mg C ha−1 yr−1 in unsustainably logged and severely degraded plots, with emissions continuing at these rates for at least one-decade post-logging. Our data directly contradict the default assumption that recovering logged and degraded tropical forests are net carbon sinks, implying the amount of carbon being sequestered across the world’s tropical forests may be considerably lower than currently estimated. Copyright © 2023 the Author(s).

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

December 22, 2022

Old-growth tropical forests are widely recognized as being immensely important for their biodiversity and high biomass1. Conversely, logged tropical forests are usually characterized as degraded ecosystems2. However, whether logging results in a degradation in ecosystem functions is less clear: shifts in the strength and resilience of key ecosystem processes in large suites of species have rarely been assessed in an ecologically integrated and quantitative framework. Here we adopt an ecosystem energetics lens to gain new insight into the impacts of tropical forest disturbance on a key integrative aspect of ecological function: food pathways and community structure of birds and mammals. We focus on a gradient spanning old-growth and logged forests and oil palm plantations in Borneo. In logged forest there is a 2.5-fold increase in total resource consumption by both birds and mammals compared to that in old-growth forests, probably driven by greater resource accessibility and vegetation palatability. Most principal energetic pathways maintain high species diversity and redundancy, implying maintained resilience. Conversion of logged forest into oil palm plantation results in the collapse of most energetic pathways. Far from being degraded ecosystems, even heavily logged forests can be vibrant and diverse ecosystems with enhanced levels of ecological function.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

June 1, 2022

The shrinking of glaciers is among the most iconic consequences of climate change. Despite this, the downstream consequences for ecosystem processes and related microbiome structure and function remain poorly understood. Here, using a space-for-time substitution approach across 101 glacier-fed streams (GFSs) from six major regions worldwide, we investigated how glacier shrinkage is likely to impact the organic matter (OM) decomposition rates of benthic biofilms. To do this, we measured the activities of five common extracellular enzymes and estimated decomposition rates by using enzyme allocation equations based on stoichiometry. We found decomposition rates to average 0.0129 (% d−1), and that decreases in glacier influence (estimated by percent glacier catchment coverage, turbidity, and a glacier index) accelerates decomposition rates. To explore mechanisms behind these relationships, we further compared decomposition rates with biofilm and stream water characteristics. We found that chlorophyll-a, temperature, and stream water N:P together explained 61% of the variability in decomposition. Algal biomass, which is also increasing with glacier shrinkage, showed a particularly strong relationship with decomposition, likely indicating their importance in contributing labile organic compounds to these carbon-poor habitats. We also found high relative abundances of chytrid fungi in GFS sediments, which putatively parasitize these algae, promoting decomposition through a fungal shunt. Exploring the biofilm microbiome, we then sought to identify bacterial phylogenetic clades significantly associated with decomposition, and found numerous positively (e.g., Saprospiraceae) and negatively (e.g., Nitrospira) related clades. Lastly, using metagenomics, we found evidence of different bacterial classes possessing different proportions of EEA-encoding genes, potentially informing some of the microbial associations with decomposition rates. Our results, therefore, present new mechanistic insights into OM decomposition in GFSs by demonstrating that an algal-based “green food web” is likely to increase in importance in the future and will promote important biogeochemical shifts in these streams as glaciers vanish.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

January 1, 2022

Relational values have recently been proposed as a concept to expand our understanding of environmental values from the categories previously dominating the discourse: instrumental (nature for people’s sake) and intrinsic values (nature for its own sake). Empirical and conceptual research on relational values has so far focused on the content of relational values or their relationship to other kinds of values. In this paper, we fill a key gap in understanding exactly what relational values are and how they work; we call this the ‘syntax’ of relational values. We do so by applying the Syntax of Environmental Values Framework, which describes relational values as bidirectional, expressed by genuine respect and care on the one hand and an eudaimonic contribution to wellbeing on the other. We developed a novel interview protocol which we applied in semistructured interviews with Swiss alpine farmers. We examine how both of these directions are manifested in farmers’ relational values. Our results showed how the bidirectionality manifests in relational values of alpine farmers. Specifically, we identified three components of each directionality. The intrinsic element of relational values was constituted by: an attitude of respect, attention to the relationship and practices of care. The instrumental element of relational values was constituted by: emotional and experiential contributions for the valuer, satisfaction and joy in the relationship, and practical contributions to the activities associated with the relationship (e.g. farm management). We further elaborate on the conditions required to sustain relational values, including physical, emotional and sociopolitical conditions. These results informed an elaborated conceptual framework of relational values, and environmental valuing more generally. While specifically derived from our dataset, we believe our conclusions could directly or in a modified form, apply to diverse cases of relational valuing. In sum, this paper offers a concrete step towards better characterizing, distinguishing and applying the relational values concept. Read the free Plain Language Summary for this article on the Journal blog.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

September 1, 2021

Science, as both a body of knowledge and a process of acquiring new knowledge, is widely regarded as playing a central role in biodiversity conservation. Science undoubtedly enhances our understanding of the drivers of biodiversity loss and assists in the formulation of practical and policy responses, but it has not yet proved sufficiently influential to reverse global trends of biodiversity decline. This review seeks to critically examine the science of biodiversity conservation and to identify any hidden assumptions that, once interrogated and explored, may assist in improving conservation science, policy and practice. By drawing on existing reviews of the literature, this review describes the major themes of the literature and examines the historical shifts in the framing of conservation. It highlights the dominance of research philosophies that view conservation through a primarily ecological lens, changes in the goal(s) of conservation and a lack of clarity over the role(s) of science in biodiversity conservation. Finally, this review offers a simple framework to more clearly and consistently conceptualize the role(s) of science in biodiversity conservation in the future. Greater critical reflection on how conservation science might better accommodate multiple knowledges, goals and values could assist in ‘opening up’ new, legitimate pathways for biodiversity conservation.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

August 1, 2021

Decades of research and policy interventions on biodiversity have insufficiently addressed the dual issues of biodiversity degradation and social justice. New approaches are therefore needed. We devised a research and action agenda that calls for a collective task of revisiting biodiversity toward the goal of sustaining diverse and just futures for life on Earth. Revisiting biodiversity involves critically reflecting on past and present research, policy, and practice concerning biodiversity to inspire creative thinking about the future. The agenda was developed through a 2-year dialogue process that involved close to 300 experts from diverse disciplines and locations. This process was informed by social science insights that show biodiversity research and action is underpinned by choices about how problems are conceptualized. Recognizing knowledge, action, and ethics as inseparable, we synthesized a set of principles that help navigate the task of revisiting biodiversity. The agenda articulates 4 thematic areas for future research. First, researchers need to revisit biodiversity narratives by challenging conceptualizations that exclude diversity and entrench the separation of humans, cultures, economies, and societies from nature. Second, researchers should focus on the relationships between the Anthropocene, biodiversity, and culture by considering humanity and biodiversity as tied together in specific contexts. Third, researchers should focus on nature and economies by better accounting for the interacting structures of economic and financial systems as core drivers of biodiversity loss. Finally, researchers should enable transformative biodiversity research and action by reconfiguring relationships between human and nonhuman communities in and through science, policy, and practice. Revisiting biodiversity necessitates a renewed focus on dialogue among biodiversity communities and beyond that critically reflects on the past to channel research and action toward fostering just and diverse futures for human and nonhuman life on Earth.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

March 1, 2021

Future global environmental change will have a significant impact on biodiversity through the intersecting forces of climate change, urbanization, human population growth, overexploitation, and pollution. This presents a fundamental challenge to conservation approaches, which seek to conserve past or current assemblages of species or ecosystems in situ. This review canvases diverse approaches to biodiversity futures, including social science scholarship on the Anthropocene and futures thinking alongside models and scenarios from the biophysical science community. It argues that charting biodiversity futures requires processes that must include broad sections of academia and the conservation community to ask what desirable futures look like, and for whom. These efforts confront political and philosophical questions about levels of acceptable loss, and how trade-offs can be made in ways that address the injustices in the distribution of costs and benefits across and within human and non-human life forms. As such, this review proposes that charting biodiversity futures is inherently normative and political. Drawing on diverse scholarship united under a banner of ‘futures thinking’ this review presents an array of methods, approaches and concepts that provide a foundation from which to consider research and decision-making that enables action in the context of contested and uncertain biodiversity futures.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

January 22, 2021

The upcoming Convention on Biological Diversity (CBD) meeting, and adoption of the new Global Biodiversity Framework, represent an opportunity to transform humanity’s relationship with nature. Restoring nature while meeting human needs requires a bold vision, including mainstreaming biodiversity conservation in society. We present a framework that could support this: the Mitigation and Conservation Hierarchy. This places the Mitigation Hierarchy for mitigating and compensating the biodiversity impacts of developments (1, avoid; 2, minimize; 3, restore; and 4, offset, toward a target such as “no net loss” of biodiversity) within a broader framing encompassing all conservation actions. We illustrate its application by national governments, sub-national levels (specifically the city of London, a fishery, and Indigenous groups), companies, and individuals. The Mitigation and Conservation Hierarchy supports the choice of actions to conserve and restore nature, and evaluation of the effectiveness of those actions, across sectors and scales. It can guide actions toward a sustainable future for people and nature, supporting the CBD’s vision. The adoption of the new Global Biodiversity Framework requires mainstreaming of biodiversity conservation into society. The Mitigation and Conservation Hierarchy places the Mitigation Hierarchy (1, avoid; 2, minimize; 3, restore; and 4, offset biodiversity impacts) within a broader framing encompassing all conservation actions. We illustrate its application by national governments, sub-national levels, companies, and individuals. This integrated framework supports the choice of actions to conserve and restore nature, and evaluation of their effectiveness, across sectors and scales.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

December 1, 2020

Narratives shape human understanding and underscore policy, practice and action. From individuals to multilateral institutions, humans act based on collective stories. As such, narratives have important implications for revisiting biodiversity. There have been growing calls for a ‘new narrative’ to underpin efforts to address biodiversity decline that, for example, foreground optimism, a more people-centred narrative or technological advances. This review presents some of the main contemporary narratives from within the biodiversity space to reflect on their underpinning categories, myths and causal assumptions. It begins by reviewing various interpretations of narrative, which range from critical views where narrative is a heuristic for understanding structures of domination, to advocacy approaches where it is a tool for reimagining ontologies and transitioning to sustainable futures. The work reveals how the conservation space is flush with narratives. As such, efforts to search for a ‘new narrative’ for conservation can be usefully informed by social science scholarship on narratives and related constructs and should reflect critically on the power of narrative to entrench old ways of thought and practice and, alternatively, make space for new ones. Importantly, the transformative potential of narrative may not lie in superficial changes in messaging, but in using narrative to bring multiple ways of knowing into productive dialogue to revisit biodiversity and foster critical reflection.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

October 27, 2020

Glacier-fed streams (GFS) are harsh ecosystems dominated by microbial life organized in benthic biofilms, yet the biodiversity and ecosystem functions provided by these communities remain under-appreciated. To better understand the microbial processes and communities contributing to GFS ecosystems, it is necessary to leverage high throughput sequencing. Low biomass and high inorganic particle load in GFS sediment samples may affect nucleic acid extraction efficiency using extraction methods tailored to other extreme environments such as deep-sea sediments. Here, we benchmarked the utility and efficacy of four extraction protocols, including an up-scaled phenolchloroform protocol. We found that established protocols for comparable sample types consistently failed to yield sufficient high-quality DNA, delineating the extreme character of GFS. The methods differed in the success of downstream applications such as library preparation and sequencing. An adapted phenol-chloroform-based extraction method resulted in higher yields and better recovered the expected taxonomic profile and abundance of reconstructed genomes when compared to commercially-available methods. Affordable and straight-forward, this method consistently recapitulated the abundance and genomes of a mock community, including eukaryotes. Moreover, by increasing the amount of input sediment, the protocol is readily adjustable to the microbial load of the processed samples without compromising protocol efficiency. Our study provides a first systematic and extensive analysis of the different options for extraction of nucleic acids from glacier-fed streams for high-throughput sequencing applications, which may be applied to other extreme environments.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

June 19, 2020

Plants emit an extraordinary diversity of chemicals that provide information about their identity and mediate their interactions with insects. However, most studies of this have focused on a few model species in controlled environments, limiting our capacity to understand plant-insect chemical communication in ecological communities. Here, by integrating information theory with ecological and evolutionary theories, we show that a stable information structure of plant volatile organic compounds (VOCs) can emerge from a conflicting information process between plants and herbivores. We corroborate this information “arms race” theory with field data recording plant-VOC associations and plant-herbivore interactions in a tropical dry forest. We reveal that plant VOC redundancy and herbivore specialization can be explained by a conflicting information transfer. Information-based communication approaches can increase our understanding of species interactions across trophic levels.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

May 1, 2020

Mountains are facing growing environmental, social, and economic challenges. Accordingly, effective policies and management approaches are needed to safeguard their inhabitants, their ecosystems, their biodiversity, and the livelihoods they support. The formulation and implementation of such policies and approaches requires a thorough understanding of, and extensive knowledge about, the interactions between nature and people particular to mountain social-ecological systems. Here, we applied the conceptual framework of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services to assess and compare the contents of 631 abstracts on the interactions among biodiversity, ecosystem services, human wellbeing, and drivers of change, and formulate a set of research recommendations. Our comparative assessment of literature pertained to the Andes, the East African mountains, the European Alps, and the Hindu Kush Himalaya. It revealed interesting differences between mountain systems, in particular in the relative importance given in the literature to individual drivers of change and to the ecosystem services delivered along elevational gradients. Based on our analysis and with reference to alternative conceptual frameworks of mountain social-ecological systems, we propose future research directions and options. In particular, we recommend improving biodiversity information, generating spatially explicit knowledge on ecosystem services, integrating knowledge and action along elevational gradients, generating knowledge on interacting effects of global change drivers, delivering knowledge that is relevant for transformative action toward sustainable mountain development, and using comprehensive concepts and codesigned approaches to effectively address knowledge gaps.

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

Published in

January 1, 2020

The water-energy-food nexus concept is criticized as not yet fit for deeply integrated and contested governance agendas. One problem is how to achieve equitable risk governance and management where there is low consensus on priorities, poor inclusion and coordination of risk assessment procedures, and a weak emphasis placed on cross-scale and sectoral interactions over time. Participatory system dynamics modeling processes and analyses are promising approaches for such challenges but are currently underutilized in nexus research and policy. This paper shares our experience implementing one such analysis in the Mekong river basin, a paradigmatic example for international nexus research. Our transdisciplinary research design combined participatory causal loop diagramming processes, scenario modeling, and a new resilience analysis method to identify and test anticipated water-energy-food risks in Kratie and Stung Treng provinces in northeastern Cambodia. Our process generated new understanding of potential cross-sectoral and cross-level risks from major hydropower development in the region. The results showed expected trade-offs between national level infrastructure programs and local level food security, but also some new insights into the effects local population increases may have on local food production and consumption even before hydropower developments are built. The analysis shows the benefit of evaluating risks in the nexus at different system levels and over time because of how system dynamics and inflection points are taken into account. Additionally, our case illustrates the contribution participatory system-thinking processes can make to risk assessment procedures for complex systems transitions. We originally anticipated that any new capacity reported by partners and participants would come from our modeling results produced at the end of the process. However, participants in the modeling procedures also found the experience powerful the information sharing, rapid risk assessment, and personal learning it enabled. A lesson from our experience reinforces a message from the transdisciplinary research field that has not yet been absorbed into the nexus research and policy field wholeheartedly: we do not have to wait for perfect data and incontestable results before making a positive contribution to anticipating and responding to risks that emerge from nexus relations if we apply participatory and systems-thinking informed approaches.

Research field(s)
Natural Sciences, Biology, Ecology