Experimental Ecosystems Research Articles

Beyond the economic boundaries to account for ecosystem services

Ecosystem services (ES) accounts are essential to quantify and monitor the contribution of ecosystems to human well-being. The System of Environmental and Economic Accounting – Experimental Ecosystem Accounting (SEEA EEA) is the first attempt to provide a set of standards to compile ecosystem accounts. We argue for the inclusion of an ecological perspective in the SEEA EEA that considers ecosystems to be more than input providers to the economy. Ecosystems can act as accounting units capable of producing, consuming and recording changes in regeneration and absorption rates. To account for that we propose (i) to identify ES typologies according to the way in which energy, biomass and information is released to generate services; (ii) to use these typologies to define the concepts of ES potential, ES potential flows, ES demand and ES actual flows; and (iii) to build the ES capacity accounts in monetary terms based on these concepts. These arguments are illustrated with case studies for water purification and crop pollination accounts in European countries. Extending the production boundary would allow the measurement of the sustainable use of ES and the establishment of causality between the use of ES and the value accrued by the economic actors and households.

Ecosystem services accounts: Valuing the actual flow of nature-based recreation from ecosystems to people

Natural capital accounting aims to measure changes in the stock of natural assets (i.e., soil, air, water and all living things) and to integrate the value of ecosystem services into accounting systems that will contribute to better ecosystems management. This study develops ecosystem services accounts at the European Union level, using nature-based recreation as a case study and following the current international accounting framework: System of Environmental-Economic Accounting – Experimental Ecosystem Accounting (SEEA EEA). We adapt and integrate different biophysical and socio-economic models, illustrating the workflow necessary for ecosystem services accounts: from a biophysical assessment of nature-based recreation to an economic valuation and compilation of the accounting tables. The biophysical assessment of nature-based recreation is based on spatially explicit models for assessing different components of ecosystem services: potential, demand and actual flow. Deriving maps of ecosystem service potential and demand is a key step in quantifying the actual flow of the service used, which is determined by the spatial relationship (i.e., proximity in the case of nature-based recreation) between service potential and demand. The nature-based recreation accounts for 2012 show an actual flow of 40 million potential visits to ‘high-quality areas for daily recreation’, with a total value of EUR 50 billion. This constitutes an important contribution of ecosystems to people's lives that has increased by 26% since 2000. Practical examples of ecosystem services accounts, as shown in this study, are required to derive recommendations and further develop the conceptual and methodological framework proposed by the SEEA EEA. This paper highlights the importance of using spatially explicit models for ecosystem services accounts. Mapping the different components of ecosystem services allows proper identification of the drivers of changes in the actual service flow derived from ecosystems, socio-economic systems and/or their spatial relationship. This will contribute to achieving one of the main goals of ecosystem accounts, namely measuring changes in natural capital, but it will also support decision-making that targets the enhancement of ecosystems, their services and the benefits they provide.

Experimental ecosystem accounting for coastal and marine areas: A pilot application of the SEEA-EEA in Long Island coastal bays

Recent international efforts have focused on the development of metrics to supplement or adjust Gross Domestic Product (GDP) to better account for the broader environmental and social impacts of economic development. In this regard, the United Nations System of Environmental-Economic Accounting, through its Experimental Ecosystem Accounting (EEA) work, is developing a standardized approach to accounting for the value of ecosystem services generated by ecosystems and documenting the relationships between ecosystem services and economic activity. Limited examples exist of the application of the EEA approach to coastal and marine habitats. The purpose of the current paper is therefore to develop a pilot process for applying the EEA within a coastal area, using South Shore Long Island Bays as a case study. Indicators of ecosystem condition and ecosystem services are proposed, data are compiled for the study site, and population of EEA tables as proposed by the United Nations is undertaken. Results indicate significant data gaps for marine and coastal areas that may limit the immediate ability to compile these ecosystem accounts. However, based on identified data gaps and implementation challenges, the process undertaken at the pilot site also provides guidance for potential future research activities.

Ecosystem Effects of Morphological and Life History Traits in Two Divergent Zooplankton Populations

Little is known about the ecosystem effects of locally adapted populations. The filter feeding copepod Eurytemora affinis is an abundant and important zooplankton in coastal waters that consist of a cryptic species complex with locally adapted populations. We used a mesocosm setup to investigate population and ecosystem interactions of two populations from the Baltic Sea with different morphology and life history traits. One population is laterally wider, larger-sized, more fecund, and have higher growth rate than the other. The experimental ecosystems varied in algae community (pelagic algae, and pelagic algae + benthic diatoms) with two resource supply scenarios. Results showed that the large-sized population is a more effective grazer. In low resource supply the small-sized population starved, whereas the large-sized population was unaffected, resulting in a larger population increase of both nauplii and copepodites than for the small-sized population. Addition of benthic diatoms to the pelagic algae community had much more negative effects on the reproduction of the large-sized population. This suggests that the large-sized population feed near benthic to a greater extent than the small-sized population, and that filamentous benthic diatoms interfere with the grazing process. Despite the negative effects of benthic diatoms, the large-sized population could maintain similar or higher reproduction than the small-sized population. In addition, the high grazing efficiency of the large-sized population resulted in a different community composition of algae. Specifically, flagellated species and small sized benthic diatoms were more grazed upon by the large-sized population. Our results show that morphologically divergent, yet phylogenetically closely related zooplankton populations can have different ecosystem functions, and in turn have different population increase in response to resource supply and algae community.

A critical review of ecosystem accounting and services frameworks

Ecological economists currently face an important opportunity to influence national policies and global awareness regarding ecosystems. Ecosystem services (ES) frameworks, including the Intergovernmental Panel on Biodiversity and Ecosystem Services (IPBES) and the System of Environmental Economic Accounting Experimental Ecosystem Accounting (SEEA EEA) will influence how national measurement systems integrate the value of ecosystems and their services into national planning and monitoring progress towards the Sustainable Development Goals (SDGs). Decision-makers are, however, faced with an embarrassment of riches. There is a multitude of ES frameworks, but no formal and integrative evaluation of the entire set exists. We review the IPBES, the SEEA EEA and 14 other ES frameworks using criteria designed to address operational and convergence considerations for national ecosystem accounting. While the frameworks reviewed incorporate many strengths, none fulfils all the criteria of a comprehensive national ecosystem accounting framework. We conclude with suggestions for conceptual, measurement and process developments to broaden the appeal, utility and acceptance of future frameworks. Considering these suggestions could substantially contribute to the development of ecosystem accounting frameworks that foster a constructive dialogue amongst the many disciplines, national contexts and viewpoints involved in understanding, measuring and making decisions about ecosystems.

A small closed ecosystem with an estimated portion of human metabolism

The study describes a small closed ecosystem used to test technologies to be further employed in full-scale manned closed ecosystems. The experimental ecosystem is designed to use a certain portion of human metabolism, which is included in the gas, water, and organic waste loops of the system. In this experimental ecosystem, gas and water loops are fully closed, and the model enables processing of human waste and plant inedible biomass. A physicochemical method is used to remove pollutants from the air in the system. A human takes part in the gas exchange of the system through its respiration loop. This experimental ecosystem can be used for testing and improving new technologies to be further used in the future space stations.

Using the raz‐rru method to examine linkages between substrate, biofilm colonisation and stream metabolism in open‐canopy streams

Abstract Understanding the mechanisms that control gross primary production (GPP) and ecosystem respiration (ER) is important in open‐canopy streams, particularly as their prevalence increases across the landscape with the expansion of human land use. We measured resazurin (raz) transformation to resorufin (rru) as an indicator of ER in two contrasting experimental stream systems to examine the linkages between underlying substrate, biofilm colonisation and stream metabolism in open‐canopy systems. We implemented a gradient of biofilm coverage (0%–100%) in 20 recirculating streams and found that raz transformation (kτ) increased proportionally with algal biomass and gross primary production (GPP). We then conducted multiple short‐term additions of raz over a 5‐month biofilm colonisation sequence in four groundwater‐fed, experimental streams (Q = 1.5 L/s, 50 m long) at the Notre Dame Linked Experimental Ecosystem Facility (ND‐LEEF). Streams at ND‐LEEF were lined with two different substrate sizes (pea gravel vs. cobble) and two levels of heterogeneity (alternating sections vs. well‐mixed). We found that longitudinal patterns of kτ varied with substrate type and heterogeneity on the majority of sampling days. Temporal patterns of kτ over the trajectory of biofilm growth were similar among streams, with “peak” kτ occurring after three months of biofilm growth; kτ decreased with the onset of algal senescence and decreasing temperatures. Raz transformation was also positively correlated with algal biomass and GPP in the streams at ND‐LEEF, which varied with substrate composition. Overall, the raz‐rru method identified spatial and temporal variability in the linkages between substrate, algal biofilms, and metabolism in open‐canopy streams.

Sustainability assessment and causality nexus through ecosystem service accounting: The case of water purification in Europe

The paper builds on the Supply and Use Tables module within the System of integrated Environmental and Economic Accounts - Experimental Ecosystem Accounts (SEEA EEA) developed by the UN. We explore the evolution of Supply and Use Tables from the System of National Accounts (SNA) to the System of integrated Environmental and Economic Accounts - Central Framework (SEEA CF) and then to the SEEA EEA, and we propose a further extension: we propose that ecosystem types should be treated as accounting units able to produce, consume and exhibit changes in regeneration and absorption rates. The implications are first explained in the methodological section and then shown in the application where the water purification service is tested against two major policy issues: sustainability assessment (we show how to assess whether the ecosystem service is used sustainably by comparing the quantification of potential and actual flow) and causality nexus (we quantify the connection between the value of agricultural production and that of the ecosystem service used). The paper highlights how the overall outcomes change when considering different scales. A contrast emerges, for example, between the positive balance at the continental scale, where water purification services appear to be used sustainably (thanks to the high potential flow of Northern European countries) and the negative balance of almost all European countries when considered at a national scale. Taking advantage of the experimental opportunities offered by operating with external satellite accounts, we are able to show how the proposed complementary tables could support policy action.

Impacts of warming on top-down and bottom-up controls of periphyton production

Global warming profoundly impacts the functioning of aquatic ecosystems. Nonetheless, the effect of warming on primary producers is poorly understood, especially periphyton production, which is affected both directly and indirectly by temperature-sensitive top-down and bottom-up controls. Here, we study the impact of warming on gross primary production in experimental ecosystems with near-realistic foodwebs during spring and early summer. We used indoor mesocosms following a temperate temperature regime (control) and a warmed (+4 °C) treatment to measure biomass and production of phytoplankton and periphyton. The mesocosms’ primary production was dominated by periphyton (>82%) during the studied period (April-June). Until May, periphyton production and biomass were significantly higher in the warm treatment (up to 98% greater biomass compared to the control) due to direct temperature effects on growth and indirect effects resulting from higher sediment phosphorus release. Subsequently, enhanced grazer abundances seem to have counteracted the positive temperature effect causing a decline in periphyton biomass and production in June. We thus show, within our studied period, seasonally distinct effects of warming on periphyton, which can significantly affect overall ecosystem primary production and functioning.

Assessment of seismic vibratory impact on experimental lakes ecosystems

The paper deals with the assessment of seismic vibratory impact on experimental lakes ecosystems. Changes of chemical and zooplanktonic composition of experimental lakes before vibration works were studied. Crucian carps were used for the assessment of vibratory impact. Hydrochemical researches included definition of organoleptic indicators, dissolved gases, biogenous elements, organic substance and the main ions, polluting substances and metals. The chemical analysis is carried out by standard hydrochemistry techniques. 18 samples on quantitative and qualitative structure of a zooplankton were collected and processed. Zooplankton organisms definition was carried out by means of widely used determinants. For icthyological researches fish caught in Nidzhili Lake was used. The bioanalysis was carried out by standard ichthyology techniques. The conducted pilot studies have shown that such quantitative and qualitative water condition changes and such vibratory impact on zooplanktonic organisms and crucians condition which we consider reaching catastrophic influences. If to take into account intensity and efficiency of fish, zooplanktonic and bentosny organisms restoration in the studied lakes, it is possible to consider that there are no cardinal changes in hydrobionts and fish fauna as a result of vibratory impact. It is also possible to assume that the essential part of such changes remains out of attention and opportunities of modern monitoring.

Designing a framework for marine ecosystem assets accounting

Marine ecosystem assets accounting is a cornerstone of the marine resource assets management; however, it is facing an imperfect accounting system in the current situation. Based on the System of Environmental Economic Accounting (SEEA) Experimental Ecosystem Accounting, this paper initially combines the key concepts, the objectives, the extent, and the tabular structure in measuring the ecosystem assets. Subsequently, with the marine ecosystems as the research object, this paper attempts to design the accounting tables for the marine ecosystems extent, marine ecosystems conditions and the expected service flows of the marine ecosystems in physical terms. Furthermore, the technical issues such as trade-off, pricing and the choice of asset discount rate on expected marine ecosystem services are explored. With the accounting of the expected marine ecosystem services in monetary terms, the calculation of the marine ecosystem assets using the net present value method is possible, and the marine ecosystem assets accounts can be compiled. Finally, this paper proposes the existing challenges and directs the need for further research in designing the framework of marine ecosystem assets accounts.

Bridging the gap between ecosystem service indicators and ecosystem accounting in Finland

In this paper, we examine how progress on ecosystem service indicators could contribute to ecosystem accounting within the scope of environmental-economic accounting in Finland. We propose an integration framework and examine the integration of ecosystem service indicators into environmental-economic accounting with two case studies relevant for Finland: (1) water-related ecosystem services and (2) the ecosystem services of fish provisioning in marine ecosystems. In light of these case studies, we evaluate the relevance of existing Finnish ecosystem service indicators, the data availability for ecosystem accounting in Finland, and the applicability of the System of Environmental-Economic Accounting ö Experimental Ecosystem Accounting (SEEA-EEA) framework to integrate Finnish ecosystem service indicators and other relevant data into environmental-economic accounts. The results indicate that the present ecosystem service indicators can assist in creating a basis for ecosystem accounting, but the indicators require further elaboration to be more compatible with the existing environmental-economic accounting system.

Envisioning future innovative experimental ecosystems through the foresight approach. Case: Design Factory

Change makers are visionaries who wish to bring change to their respective fields. As technological change is accelerating, it is relevant to consider, how the way and what we teach can evolve with the future to remain meaningful and pioneering. Design Factory at Aalto University, as an innovative experimental ecosystem with interdisciplinary principles and new teaching methodologies has been successful in and at the forefront in educating the students to be change-makers. The paper presents a case study of holistically anticipating plausible futures for innovative experimental ecosystems utilizing a foresight approach. We analyze how the ways of working, spaces, and teaching methods of one such ecosystem, Design Factory at Aalto University in Finland, could support students learning in the year 20 × 6 {x = 2, 3}. We present the process of drawing virtual lines that connect trends, future drivers, visions, and scenarios using a contemporary approach that fuses qualitative and quantitative methods. The results from the study are six future scenarios for the Design Factory, that have implications for innovation ecosystems in general. These results are expected to further foster or trigger new research and development experiments, directions for building radical environments, new teaching methods and ways of working.

Diversity-dependent temporal divergence of ecosystem functioning in experimental ecosystems.

The effects of biodiversity on ecosystem functioning generally increase over time but the underlying processes remain unclear. Using 26 long-term grassland and forest experimental ecosystems we demonstrate that biodiversity-ecosystem functioning relationships strengthen mainly by greater increases in functioning in high-diversity communities in grasslands and forests. In grasslands, biodiversity effects also strengthen due to decreases in functioning in low-diversity communities. Contrasting trends across grasslands are associated with differences in soil characteristics.

Trophic dynamics in a simple experimental ecosystem: Interactions among centipedes, Collembola and introduced earthworms

Invasive earthworms in North America are known to have dramatic influences on soil ecosystems, including negative effects on other soil fauna. In general, studies examining this phenomenon have focused on invasive earthworm impacts on organisms at the same or lower trophic level as the earthworms themselves (i.e., detritivores and decomposers). In contrast, there have been relatively few studies of invasive earthworm impacts on higher trophic levels or food web interactions. Invasive earthworms might alter food webs either directly as prey items, or indirectly through their profound alteration of soil physical characteristics, which might in turn alter established predator/prey interactions. In this study, we created experimental mesocosms to investigate the influence of an invasive earthworm on a native predator-prey interaction. We incubated several combinations of a widespread Asian invasive earthworm (Amynthas agrestis), a generalist centipede predator (family: Cryptopidae), and a putative microarthropod prey species (Sinella curviseta) in an experiment to determine their interactions. We hypothesized that collembolan abundance would be reduced in mesocosms containing centipedes. We further hypothesized that earthworm feeding on litter substrate in the mesocosms would reduce the complexity of the substrate, and thus increase the likelihood of centipede/collembolan encounters, with the ultimate effect of more pronounced reduction of Collembola populations in mesocosms containing both earthworms and centipedes. Unexpectedly, we found that earthworms had a negative effect on collembolan abundance early in the incubation and that centipedes did not. Collembolan populations were less variable through time in the presence of earthworms, suggesting that invasive earthworms exerted some regulatory pressure on food or habitat supply for the collembolans. Centipedes lost biomass when only Collembola were available for food, but gained biomass when incubated with earthworms. We noted a simultaneous significant decrease in earthworm biomass (mainly in the form of earthworm mortality) in experimental units that contained centipedes relative to those without centipedes. Taken together, these results suggest that this invasive earthworm may represent a novel prey resource for the centipedes, and that their presence in ecosystems could have consequences on both higher and lower trophic levels.

Removal of aluminum by aquatic plants Ceratophyllum demersum and Chara fragilis from water of experimental ecosystems

Changes in the concentration of the aluminum ions in water of experimental systems (microcosms) have been studied. The Al ion concentration was measured by the fluorescent method. As macrophytes for microcosm incubation served hornwort Ceratophyllum demersum and stonewort Chara fragilis, with the latter hydrobiont used for the first time in similar experiments. It has been convincingly proven that, in the microcosms with the aquatic plants tested, the Al ion concentration decreased much faster than in the macrophyte-free control microcosms. The data obtained suggest that Ceratophyllum demersum and Chara fragilis are promising candidates for phytoremediation applications.

Physical and monetary ecosystem service accounts for Europe: A case study for in-stream nitrogen retention

In this paper we present a case study of integrated ecosystem and economic accounting based on the System of Environmental Economic Accounting — Experimental Ecosystem Accounts (SEEA-EEA). We develop accounts, in physical and monetary terms, for the water purification ecosystem service in Europe over a 20-year time period (1985–2005). The estimation of nitrogen retention is based on the GREEN biophysical model, within which we impose a sustainability threshold to obtain the physical indicators of capacity – the ability of an ecosystem to sustainably supply ecosystem services. Key messages of our paper pertain the notion of capacity, operationalized in accounting terms with reference to individual ecosystem services rather than to the ecosystem as a whole, and intended as the stock that provides the sustainable flow of the service. The study clarifies the difference between sustainable flow and actual flow of the service, which should be calculated jointly so as to enable an assessment of the sustainability of current use of ecosystem services. Finally, by distinguishing the notion of ‘process’ (referred to the ecosystem) from that of ‘capacity’ (pertaining specific services) and proposing a methodology to calculate capacity and flow, we suggest an implementable way to operationalize the SEEA-EEA accounts.

The potential of carbon dioxide capture and sequestration with algae

Algae are generally accepted as an excellent option for greenhouse gas control, but the ecological niche of algal CO2 bio-fixation is not completely understood today. This study showed an excellent CO2 uptake rate of 159mgL−1day−1 and CO2 consumption efficiency of 93% in comparison to the continuously stirred tank reactor (178mgL−1day−1 and 96%). Thus, the experimental ecosystem that imitated the freshwater algal niche had a similar CO2 uptake performance to the artificial ideal mixing reactor prototype. To investigate terrestrial plants as a carbon sink, we compared CO2 fixation rates among species, geographic areas, plant ages, and lignin contents; in the tropical zone, forest plantations had higher growth rates, higher lignin content, and higher CO2 uptake rates. In addition, natural forests and old plantations had the highest CO2 consumption efficiency. Furthermore, we found that algae had the highest CO2 uptake rates and CO2 consumption efficiency, a characteristic that is not found in other plants. Therefore, algae were able to accumulate large carbon stores within a short period of time and were able to play a critical role as a biological sink in the carbon cycle.

Challenges and Directions for the Advancement of Estuarine Ecosystem Science

Estuarine ecosystem ecology is a dynamic field of study that has historically focused on a spectrum of compelling research topics, and here we present a series of perspectives on the major challenges to be overcome and key research questions to be addressed toward making progress over the coming decades. The challenges we identify include (1) maintaining and improving spatially distributed time-series datasets, (2) maximizing innovation by harnessing new technologies, (3) resuscitating experimental ecosystem research for estuaries, (4) integrating diagnostic ecological models into ecosystem research, and (5) improving basic science by linking it to applied research. We also raise a number of key research questions for the field, including (1) how does food web function respond to changing climate and nutrients, (2) what are likely trajectories of ecosystem recovery in response to restoration, (3) how does climate alter seasonality of estuarine ecosystem processes, (4) how do estuaries affect the global carbon budget and what are key feedbacks, and (5) how will tidal wetland ecosystems respond to sea level rise and climate change? Looking ahead, we envision that the field of estuarine ecosystem ecology will continue to build upon its rich tradition to address fundamental research questions with an expanded toolkit and enlightened perspective to focus basic science on the knowledge needs of society.

Cross-habitat effects shape the ecosystem consequences of co-invasion by a pelagic and a benthic consumer.

Invasive species can have major impacts on ecosystems, yet little work has addressed the combined effects of multiple invaders that exploit different habitats. Two common invaders in aquatic systems are pelagic fishes and crayfishes. Pelagic-oriented fish effects are typically strong on the pelagic food web, whereas crayfish effects are strong on the benthic food web. Thus, co-invasion may generate strong ecological responses in both habitats. We tested the effects of co-invasion on experimental pond ecosystems using two widespread invasive species, one pelagic (western mosquitofish) and one benthic (red swamp crayfish). As expected, mosquitofish had strong effects on the pelagic food web, reducing the abundance of Daphnia and causing a strong trophic cascade (increase in phytoplankton). Crayfish had strong effects on the benthic food web, reducing the abundance of benthic filamentous algae. Yet, we also found evidence for important cross-habitat effects. Mosquitofish treatments reduced the biomass of benthic filamentous algae, and crayfish treatments increased Daphnia and phytoplankton abundance. Combined effects of mosquitofish and crayfish were primarily positively or negatively additive, and completely offsetting for some responses, including gross primary production (GPP). Though co-invasion did not affect GPP, it strongly shifted primary production from the benthos into the water column. Effects on snail abundance revealed an interaction; snail abundance decreased only in the presence of both invaders. These results suggest that cross-habitat effects of co-invaders may lead to a variety of ecological outcomes; some of which may be unpredictable based on an understanding of each invader alone.