ABSTRACT
Human land use changes are threatening the integrity and health of coastal ecosystems worldwide. Intensified land use for anthropogenic purposes increases sedimentation rates, pollutants, and nutrient concentrations into adjacent coastal areas, often with detrimental effects on marine life and ecosystem functioning. However, how these factors interact to influence ecosystem health in mangrove forests is poorly understood. This study investigates the effects of catchment human land use on mangrove forest architecture and sedimentary attributes at a landscape-scale. Thirty sites were selected along a gradient of human land use within a narrow latitudinal range, to minimise the effects of varying climatic conditions. Land use was quantified using spatial analysis tools with existing land use databases (LCDB5). Twenty-six forest architectural and sedimentary variables were collected from each site. The results revealed a significant effect of human land use on ten out of 26 environmental variables. Eutrophication, characterised by changes in redox potential, pH, and sediment nutrient concentrations, was strongly associated with increasing human land use. The δ15N values of sediments and leaves also indicated increased anthropogenic nitrogen input. Furthermore, the study identified a positive correlation between human land use and tree density, indicating that increased nutrient delivery from catchments contributes to enhanced mangrove growth. Propagule and seedling densities were also positively correlated with human land use, suggesting potential recruitment success mechanisms. This research underpins the complex interactions between human land use and mangrove ecosystems, revealing changes in carbon dynamics, potential alterations in ecosystem services, and a need for holistic management approaches that consider the interconnectedness of species and their environment. These findings provide essential insights for regional ecosystem models, coastal management, and restoration strategies to address the impacts of human pressures on temperate mangrove forests, even in estuaries that may be relatively healthy.
Subject(s)
Environmental Monitoring , Wetlands , Forests , Conservation of Natural Resources , EutrophicationABSTRACT
Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha-1 in the top 30 cm and 231 ± 134 Mg SOC ha-1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies.
ABSTRACT
The waters around New Zealand are a global hotspot of biodiversity for deep-water corals; approximately one sixth of the known deep-water coral species of the world have been recorded in the region. Deep-water corals are vulnerable to climate-related stressors and from the damaging effects of commercial fisheries. Current protection measures do not account for the vulnerability of deep-water corals to future climatic conditions, which are predicted to alter the distribution of suitable habitat for them. Using recently developed habitat suitability models for 12 taxa of deep-water corals fitted to current and future seafloor environmental conditions (under different future climatic conditions: SSP2 - 4.5 and SSP3 - 7.0) we explore possible levels of spatial protection using the decision-support tool Zonation. Specifically, we assess the impact of bottom trawling on predictions of current distributions of deep-water corals, and then assess the effectiveness of possible protection for deep-water corals, while accounting for habitat refugia under future climatic conditions. The cumulative impact of bottom trawling was predicted to impact all taxa, but particularly the reef-forming corals. Core areas of suitable habitat were predicted to decrease under future climatic conditions for many taxa. We found that designing protection using current day predictions alone, having accounted for the impacts of historic fishing impacts, was unlikely to provide adequate conservation for deep water-corals under future climate change. Accounting for future distributions in spatial planning identified areas which may provide climate refugia whilst still providing efficient protection for current distributions. These gains in conservation value may be particularly important given the predicted reduction in suitable habitat for deep-water corals due to bottom fishing and climate change. Finally, the possible impact that protection measures may have on deep-water fisheries was assessed using a measure of current fishing value (kg km-2 fish) and future fishing value (predicted under future climate change scenarios).
ABSTRACT
To halt further destruction of the biosphere, most people and societies around the globe need to transform their relationships with nature. The internationally agreed vision under the Convention of Biological Diversity-Living in harmony with nature-is that "By 2050, biodiversity is valued, conserved, restored and wisely used, maintaining ecosystem services, sustaining a healthy planet and delivering benefits essential for all people". In this context, there are a variety of debates between alternative perspectives on how to achieve this vision. Yet, scenarios and models that are able to explore these debates in the context of "living in harmony with nature" have not been widely developed. To address this gap, the Nature Futures Framework has been developed to catalyse the development of new scenarios and models that embrace a plurality of perspectives on desirable futures for nature and people. In this paper, members of the IPBES task force on scenarios and models provide an example of how the Nature Futures Framework can be implemented for the development of illustrative narratives representing a diversity of desirable nature futures: information that can be used to assess and develop scenarios and models whilst acknowledging the underpinning value perspectives on nature. Here, the term illustrative reflects the multiple ways in which desired nature futures can be captured by these narratives. In addition, to explore the interdependence between narratives, and therefore their potential to be translated into scenarios and models, the six narratives developed here were assessed around three areas of the transformative change debate, specifically, (1) land sparing vs. land sharing, (2) Half Earth vs. Whole Earth conservation, and (3) green growth vs. post-growth economic development. The paper concludes with an assessment of how the Nature Futures Framework could be used to assist in developing and articulating transformative pathways towards desirable nature futures. Supplementary Information: The online version contains supplementary material available at 10.1007/s11625-023-01316-1.
ABSTRACT
Current food production and consumption trends are inconsistent with the Convention on Biological Diversity's 2050 vision of living in harmony with nature. Here, we examine how, and under what conditions, the post-2020 biodiversity framework can support transformative change in food systems. Our analysis of actions proposed in four science-policy fora reveals that subsidy reform, valuation, food waste reduction, sustainability standards, life cycle assessments, sustainable diets, mainstreaming biodiversity, and strengthening governance can support more sustainable food production and consumption. By considering barriers and opportunities of implementing these actions in Peru and the United Kingdom, we derive potential targets and indicators for the post-2020 biodiversity framework. For targets to support transformation, genuine political commitment, accountability and compliance, and wider enabling conditions and actions by diverse agents are needed to shift food systems onto a sustainable path.
Subject(s)
Food , Refuse Disposal , Biodiversity , Conservation of Natural Resources , Diet , PeruABSTRACT
Unvegetated, intertidal sandflats play a critical role in estuarine carbon and nutrient dynamics. However, these ecosystems are under increasing threat from anthropogenic stressors, especially nitrogen enrichment. While research in this area typically focuses on sediment-water exchanges of carbon and nutrients during tidal inundation, there remain significant gaps in our understanding of GHG (Greenhouse Gas) fluxes during tidal emergence. Here we use in situ benthic chambers to quantify GHG fluxes during tidal emergence and investigate the impact of nitrogen enrichment on these fluxes. Our results demonstrate significant differences in magnitude and direction of GHG fluxes between emerged and submerged flats, demonstrating the importance of considering tidal state when estimating GHG emissions from intertidal flats. These responses were related to differences in microphytobenthic and macrofaunal activity, illustrating the important role of ecology in mediating fluxes from intertidal flats. Our results further demonstrate that nitrogen enrichment of 600 gN m-2 was associated with, on average, a 1.65x increase in CO2 uptake under light (photosynthetically active) conditions and a 1.35x increase in CO2 emission under dark conditions, a 3.8x increase in CH4 emission and a 15x increase in N2O emission overall. This is particularly significant given the large area intertidal flats cover globally, and their increasing exposure to anthropogenic stressors.
ABSTRACT
Estuaries are subject to disturbance by land-based sediment and nutrient inputs, resulting in changes to the ecosystems and the functions and services that they support. Spatial mapping tools that identify how functional hotspots in the estuary may shift in location and intensity under different disturbance scenarios highlight to managers the trajectory of change and the value of active management and restoration, but to date these tools are only available in the most intensively researched ecosystems. Using empirical data derived from long-term monitoring and multi-habitat field experiments we developed future scenarios representing different impacts of environmental degradation on estuarine ecosystem functions that are important for supporting ecosystem services. We used the spatial prioritization software Zonation in a novel fashion to assess effects of different disturbance scenarios on critical soft-sediment ecosystem processes (nutrient fluxes and sediment erodibility measures) that are influenced by macrofaunal communities and local environment conditions. We compared estimates of current conditions with three scenarios linked to changes in land-use and resulting downstream impacts on estuarine ecosystems to determine how disturbance influences the distribution of high value areas for ecosystem function. Scenarios investigated the implications of habitat degradation associated with sediment deposition and declines in large sediment-dwelling animal abundance whose behavior has important influences on ecosystem function. Our analyses demonstrate decreases in the majority of ecosystem processes under scenarios associated with disturbances. These results suggest that it is important to restore biodiversity and ecosystem function and that the application of Zonation in this context offers a simple, rapid and cost-effective way of identifying priority actions and locations for restoration, and how these shift due to multiple impacts.
Subject(s)
Ecosystem , Estuaries , Animals , BiodiversityABSTRACT
Abstract: Extensive anthropogenic activities driven by the demand for agriculture and forestry products have led to dramatic reductions in biodiversity worldwide and significant changes in the provisioning of ecosystem services. These trends are expected to continue in the future as the world continues to develop without much consideration of the role that nature plays in sustaining human livelihoods. Scenarios and models can be important tools to help policy- and decision-makers foresee the impact of their decisions; thus, increasing capacity in creating such models and scenarios is of utmost importance. However, postgraduate training schools that focus on this topic are still rare. Here we present and reflect on the experience of the São Paulo School of Advanced Science on Scenarios and Modelling on Biodiversity and Ecosystem Services to Support Human Well-Being (SPSAS Scenarios). In addition, we introduce the Special Issue of Biota Neotropica that resulted from the activities taking place during the SPSAS Scenarios. In total, nine case studies emerged from the activities carried out during SPSAS Scenarios. These focused on a variety of ecosystems, their current drivers of change and expected trends, as well as on the development of alternative positive scenarios applying the recently developed Nature Futures Framework. We emphasize the need to increase capacity in scenario and modelling skills in order to address some of the existing gaps in producing policy-relevant scenarios and models for biodiversity and ecosystem services.
Resumo: Atividades antropogênicas extensas, impulsionadas pela demanda por produtos da agricultura e da silvicultura, têm levado a reduções dramáticas na biodiversidade mundial e a mudanças significativas no provimento de serviços ecossistêmicos. Estas tendências devem continuar no futuro, pois o mundo continua a se desenvolver sem muita consideração pelo papel que a natureza desempenha em sustentar a subsistência humana. Cenários e modelos são ferramentas importantes para ajudar os tomadores de decisão a preverem o impacto de suas decisões, auxiliando na definição das melhores opções para políticas de conservação e uso sustentável; portanto o aumento da capacidade para o desenvolvimento de modelos e cenários é de suma importância. Entretanto, ainda são raros os cursos de pós-graduação que foquem na capacitação de profissionais para o desenvolvimento de modelos e cenários em biodiversidade e serviços ecossistêmicos. Neste trabalho apresentamos a experiência da Escola São Paulo de Ciências Avançadas de Cenários e Modelagem em Biodiversidade e Serviços Ecossistêmicos para Apoiar o Bem-Estar Humano (SPSAS Scenarios). Adicionalmente, apresentamos neste Número Especial da Biota Neotropica os resultados dos exercícios de modelagem e cenários desenvolvidos no decorrer da SPSAS Scenarios. No total, as atividades realizadas durante o SPSAS Scenarios resultaram em nove estudos de caso. Estes se concentraram em uma diversidade de ecossistemas, nos atuais drivers de mudança e as respectivas tendências, bem como nas alternativas de desenvolvimento visando cenários mais positivos propostos recentemente no contexto da Framework Futuros para Natureza da Plataforma Intergovernamental de Biodiversidade e Serviços Ecossistêmicos (IPBES). Enfatizamos aqui a necessidade de acelerar a capacitação de profissionais que trabalhem com cenários e modelagem de forma a preencher algumas lacunas existentes na produção de cenários e modelos relevantes para a tomada de decisão em biodiversidade e serviços ecossistêmicos
ABSTRACT
The trace elemental composition of biogenic calcium carbonate (CaCO3) structures is thought to reflect environmental conditions at their time of formation. As CaCO3 structures such as shell are deposited incrementally, sequential analysis of these structures allows reconstructions of animal movements. However, variation driven by genetics or ontogeny may interact with the environment to influence CaCO3 composition. This study examined how genetics, ontogeny, and the environment influence shell composition of the bivalve Perna canaliculus. We cultured genetically distinct families at two sites in situ and in the laboratory. Analyses were performed on shell formed immediately prior to harvest on all animals as well as on shell formed early in life only on animals grown in the laboratory. Discriminant analysis using 8 elements (Co, Ti, Li, Sr, Mn, Ba, Mg, Pb, Ci, Ni) classified 80% of individuals grown in situ to their family and 92% to growth site. Generalised linear models showed genetics influenced all elements, and ontogeny affected seven of eight elements. This demonstrates that although genetics and ontogeny influence shell composition, environmental factors dominate. The location at which shell material formed can be identified if environmental differences exist. Where no environmental differences exist, genetically isolated populations can still be identified.
Subject(s)
Animal Shells/metabolism , Perna , Animals , Perna/genetics , Perna/metabolismABSTRACT
Analysis of the biological traits (e.g., feeding mode and size) that control how organisms interact with their environment has been used to identify environmental drivers of, or impacts on, species and to explain the importance of biodiversity loss. Biological trait analysis (BTA) could also be used within risk-assessment frameworks or in conservation planning if one understands the groups of traits that predict the sensitivity of habitats or communities to specific human activities. Deriving sensitivities from BTA should extend sensitivity predictions to a variety of habitats, especially those in which it would be difficult to conduct experiments (e.g., due to depth or risk to human life) and to scales beyond the norm of most experiments. We used data on epibenthos, collected via video along transects at 27 sites in a relatively pristine region of the seafloor, to determine scales of natural spatial variability of derived sensitivities and the degree to which predictions of sensitivity differed among 3 stressors (extraction of species, sedimentation, and suspended sediments) or were affected by underlying community compositions. We used 3 metrics (weighted abundance, abundance of highly sensitive species, and number of highly sensitive species) to derive sensitivity to these stressors and simulated the ability of these metrics to detect a range of stressor intensities. Regardless of spatial patterns of sensitivities across the sampled area, BTA distinguished differences in sensitivity to different stressors. The BTA also successfully separated differences in community composition from differences in sensitivity to stressors. Conversely, the 3 metrics differed widely in their ability to detect simulated impacts and likely reflect underlying ecological processes, suggesting that use of multiple metrics would be informative for spatial planning and allocating conservation priorities. Our results suggest BTA could be used as a first step in strategic prioritization of protected areas and as an underlying layer for spatial planning.
Subject(s)
Biodiversity , Conservation of Natural Resources , Ecology , Ecosystem , Human Activities , HumansABSTRACT
Macrofauna are important contributors to estuarine ecosystem services within and outside of seagrass beds. Here we documented the natural recolonisation of a temperate seagrass (Zostera muelleri) community over 15 years in an urban estuary (Waitemata Harbour, North Island, New Zealand). We also investigated the change in macrofaunal communities in relation to seagrass cover over time, from transition from bare sandflat to seagrass. Colonisation by seagrass was associated with an increase in macrofaunal species diversity (from an average of 32 species per core in 2001 to 46 species per core in 2015) and abundance (from 482 to 2273 individuals per core), as well as an increase in sediment mud (from 4.09% to 12.37%) and organic matter content (from 0.90% to 1.41%). The most abundant species within both seagrass and adjacent unvegetated sandflat were similar, the polychaetes Heteromastus filiformis, Aricidea sp., and Prionospio aucklandica, and the amphipod Paracalliope novizealandiae. The difference in macrofaunal community structure between seagrass and unvegetated sandflat was primarily associated with higher abundance of P. novizealandiae and lower abundance of Pseudopolydora sp. in seagrass. A successional effect was observed in macrofaunal communities over the 15 years following seagrass expansion, primarily associated with an increase in the abundance of Aricidea sp., H. filiformis, and P. novizealandiae, and a reduction in the abundance of the bivalve Linucula hartvigiana. This study is the first to document long-term changes in seagrass and their associated communities during a natural recolonisation event, providing insight into timeframes required both for the regrowth of a seagrass meadow from initial colonisation of individual patches, as well as the trajectories and timeframes of change from a sandflat to a seagrass-associated macrofaunal community. This research enhances our understanding of how changes in seagrass distributions due to seagrass loss or restoration may affect macrofaunal community composition and ultimately ecosystem function.
Subject(s)
Amphipoda/growth & development , Bivalvia/growth & development , Polychaeta/growth & development , Zosteraceae/growth & development , Amphipoda/classification , Animals , Biodiversity , Bivalvia/classification , Cluster Analysis , Estuaries , Geologic Sediments , New Zealand , Polychaeta/classification , Urban RenewalABSTRACT
The loss of mangrove ecosystems is associated with numerous impacts on coastal and estuarine function, including sediment carbon and nutrient cycling. In this study we compared in situ fluxes of carbon dioxide (CO2) from the sediment to the atmosphere, and fluxes of dissolved inorganic nutrients and oxygen across the sediment-water interface, in intact and cleared mangrove and sandflat ecosystems in a temperate estuary. Measurements were made 20 and 25months after mangrove clearance, in summer and winter, respectively. Sediment CO2 efflux was over two-fold higher from cleared than intact mangrove ecosystems at 20 and 25months after mangrove clearance. The higher CO2 efflux from the cleared site was explained by an increase in respiration of dead root material along with sediment disturbance following mangrove clearance. In contrast, sediment CO2 efflux from the sandflat site was negligible (≤9.13±1.18mmolm-2d-1), associated with lower sediment organic matter content. The fluxes of inorganic nutrients (NH4+, NOx and PO43-) from intact and cleared mangrove sediments were low (≤20.37±18.66µmolm-2h-1). The highest NH4+ fluxes were measured at the sandflat site (69.21±13.49µmolm-2h-1). Lower inorganic nutrient fluxes within the cleared and intact mangrove sites compared to the sandflat site were associated with lower abundance of larger burrowing macrofauna. Further, a higher fraction of organic matter, silt and clay content in mangrove sediments may have limited nutrient exchange.
ABSTRACT
Detrital subsidies from marine macrophytes are prevalent in temperate estuaries, and their role in structuring benthic macrofaunal communities is well documented, but the resulting impact on ecosystem function is not understood. We conducted a field experiment to test the effects of detrital decay on soft-sediment primary production, community metabolism and nutrient regeneration (measures of ecosystem function). Twenty four (2 m(2)) plots were established on an intertidal sandflat, to which we added 0 or 220 g DW m(-2) of detritus from either mangroves (Avicennia marina), seagrass (Zostera muelleri), or kelp (Ecklonia radiata) (n = 6 plots per treatment). Then, after 4, 17 and 46 d we measured ecosystem function, macrofaunal community structure and sediment properties. We hypothesized that (1) detrital decay would stimulate benthic primary production either by supplying nutrients to the benthic macrophytes, or by altering the macrofaunal community; and (2) ecosystem responses would depend on the stage and rate of macrophyte decay (a function of source). Avicennia detritus decayed the slowest with a half-life (t50) of 46 d, while Zostera and Ecklonia had t50 values of 28 and 2.6 d, respectively. However, ecosystem responses were not related to these differences. Instead, we found transient effects (up to 17 d) of Avicennia and Ecklonia detritus on benthic primary production, where initially (4 d) these detrital sources suppressed primary production, but after 17 d, primary production was stimulated in Avicennia plots relative to controls. Other ecosystem function response variables and the macrofaunal community composition were not altered by the addition of detritus, but did vary with time. By sampling ecosystem function temporally, we were able to capture the in situ transient effects of detrital subsidies on important benthic ecosystem functions.
Subject(s)
Aquatic Organisms/growth & development , Ecosystem , Geologic Sediments , Time FactorsABSTRACT
The ocean provides food, economic activity, and cultural value for a large proportion of humanity. Our knowledge of marine ecosystems lags behind that of terrestrial ecosystems, limiting effective protection of marine resources. We describe the outcome of 2 workshops in 2011 and 2012 to establish a list of important questions, which, if answered, would substantially improve our ability to conserve and manage the world's marine resources. Participants included individuals from academia, government, and nongovernment organizations with broad experience across disciplines, marine ecosystems, and countries that vary in levels of development. Contributors from the fields of science, conservation, industry, and government submitted questions to our workshops, which we distilled into a list of priority research questions. Through this process, we identified 71 key questions. We grouped these into 8 subject categories, each pertaining to a broad component of marine conservation: fisheries, climate change, other anthropogenic threats, ecosystems, marine citizenship, policy, societal and cultural considerations, and scientific enterprise. Our questions address many issues that are specific to marine conservation, and will serve as a road map to funders and researchers to develop programs that can greatly benefit marine conservation.
Subject(s)
Biodiversity , Conservation of Natural Resources , Ecosystem , Oceans and SeasABSTRACT
Managing coral reefs for resilience to climate change is a popular concept but has been difficult to implement because the empirical scientific evidence has either not been evaluated or is sometimes unsupportive of theory, which leads to uncertainty when considering methods and identifying priority reefs. We asked experts and reviewed the scientific literature for guidance on the multiple physical and biological factors that affect the ability of coral reefs to resist and recover from climate disturbance. Eleven key factors to inform decisions based on scaling scientific evidence and the achievability of quantifying the factors were identified. Factors important to resistance and recovery, which are important components of resilience, were not strongly related, and should be assessed independently. The abundance of resistant (heat-tolerant) coral species and past temperature variability were perceived to provide the greatest resistance to climate change, while coral recruitment rates, and macroalgae abundance were most influential in the recovery process. Based on the 11 key factors, we tested an evidence-based framework for climate change resilience in an Indonesian marine protected area. The results suggest our evidence-weighted framework improved upon existing un-weighted methods in terms of characterizing resilience and distinguishing priority sites. The evaluation supports the concept that, despite high ecological complexity, relatively few strong variables can be important in influencing ecosystem dynamics. This is the first rigorous assessment of factors promoting coral reef resilience based on their perceived importance, empirical evidence, and feasibility of measurement. There were few differences between scientists' perceptions of factor importance and the scientific evidence found in journal publications but more before and after impact studies will be required to fully test the validity of all the factors. The methods here will increase the feasibility and defensibility of including key resilience metrics in evaluations of coral reefs, as well as reduce costs. Adaptation, marine protected areas, priority setting, resistance, recovery.