Causes and consequences of recent degradation of the Magdalena River basin, Colombia

The Magdalena River in Colombia is one of the world's largest (discharge = 7100 m3 s−1) tropical rivers, hosting > 170 aquatic vertebrate species. However, concise synthesis of the current ecological and environmental status is lacking. By documenting the anthropogenic stressors impacting the river on time scales ranging from centuries to decades, we found that the river system is subject to the compounding impacts of climate change, river impoundment, invasive alien species (IAS), catchment deforestation, and water pollution. We show that the Magdalena is a woefully understudied ecosystem relative to its critical importance to Colombia's economy, culture, and biodiversity compared with other similarly sized tropical rivers. We emphasize the need for research on (1) IAS population and ecological dynamics, (2) river damming and its links with IAS and climate change, and (3) land-use changes as well as identifying sources of water pollution and strategies for mitigation

Data for wetlandscapes and their changes around the world

Geography and associated hydrological, hydroclimate and land-use conditions and their changes determine the states and dynamics of wetlands and their ecosystem services. The influences of these controls are not limited to just the local scale of each individual wetland but extend over larger landscape areas that integrate multiple wetlands and their total hydrological catchment – the wetlandscape. However, the data and knowledge of conditions and changes over entire wetlandscapes are still scarce, limiting the capacity to accurately understand and manage critical wetland ecosystems and their services under global change. We present a new Wetlandscape Change Information Database (WetCID), consisting of geographic, hydrological, hydroclimate and land-use information and data for 27 wetlandscapes around the world. This combines survey-based local information with geographic shapefiles and gridded datasets of large-scale hydroclimate and land-use conditions and their changes over whole wetlandscapes. Temporally, WetCID contains 30-year time series of data for mean monthly precipitation and temperature and annual land-use conditions. The survey-based site information includes local knowledge on the wetlands, hydrology, hydroclimate and land uses within each wetlandscape and on the availability and accessibility of associated local data. This novel database (available through PANGAEA https://doi.org/10.1594/PANGAEA.907398; Ghajarnia et al., 2019) can support site assessments; cross-regional comparisons; and scenario analyses of the roles and impacts of land use, hydroclimatic and wetland conditions, and changes in whole-wetlandscape functions and ecosystem services

Priorities and interactions of Sustainable Development Goals (SDGs) with focus on wetlands

Wetlands are often vital physical and social components of a country's natural capital, as well as providers of ecosystem services to local and national communities. We performed a network analysis to prioritize Sustainable Development Goal (SDG) targets for sustainable development in iconic wetlands and wetlandscapes around the world. The analysis was based on the information and perceptions on 45 wetlandscapes worldwide by 49 wetland researchers of the GlobalWetland Ecohydrological Network (GWEN). We identified three 2030 Agenda targets of high priority across the wetlandscapes needed to achieve sustainable development: Target 6.3-'Improve water quality'; 2.4-'Sustainable food production'; and 12.2-'Sustainable management of resources'. Moreover, we found specific feedback mechanisms and synergies between SDG targets in the context of wetlands. The most consistent reinforcing interactions were the influence of Target 12.2 on 8.4-'Efficient resource consumption'; and that of Target 6.3 on 12.2. The wetlandscapes could be differentiated in four bundles of distinctive priority SDG-targets: 'Basic human needs', 'Sustainable tourism', 'Environmental impact in urban wetlands', and 'Improving and conserving environment'. In general, we find that the SDG groups, targets, and interactions stress that maintaining good water quality and a 'wise use' of wetlandscapes are vital to attaining sustainable development within these sensitive ecosystems. © 2019 by the authors

Correction: Priorities and interactions of sustainable development goals (SDGs) with focus on wetlands. Water 2019, 11, 619 doi: 10.3390/w11030619

10.3390/w12010088Water (Switzerland)1218

Ecosystem services of wetlands and wetlandscapes under hydro-climatic change : Impacts of water flow and inundation patterns

Wetlands provide ecosystem services valuable for human society and are therefore often considered as nature based solution to different environmental problems. However, with centuries of wetland degradation due to anthropogenic pressures, such as agricultural expansion and forest industry, as well as pressures from climate change, there are large challenges for sustainable wetland management. Thus, for wetland protection and restoration practices to be successful, a deepened understanding on the actual mechanisms controlling wetland functions is required. Understanding how wetlands are connected, with and influenced, by their surrounding environment is also needed. Although most pressures experienced by wetlands operate on scales beyond the individual wetland scale, relatively few studies have thus far addressed large-scale functions and ecosystem service provision from hydrologically interconnected wetlands at the scale of wetlandscapes (i.e., the wetlands’ aggregated hydrological catchments in the landscape). The aim of this thesis is to investigate ecosystem service delivery from wetlands and wetlandscapes under hydro-climatic changes, considering 25 different wetlandscapes located in four different climate zones of the world. The thesis also systematically quantifies ecohydrological characteristics important for ecosystem service delivery and biodiversity support of wetlands and wetlandscapes in the Norrström Drainage basin located near Stockholm, Sweden.  Conducted hydro-climatic analyses showed that impacts of climate change on wetlandscapes cannot be fully understood from average changes in climatic variables of the climate zones within which the wetlandscapes are located. This may be due to the fact that wetlands are not randomly and evenly distributed within climate zones, but may be located in areas subject to stronger climatic changes than regional means. In addition, anthropogenic pressures were on average shown to have higher impacts on runoff in wetlandscapes in comparison to climate change. The pressures however showed relatively large variability between different wetlandscapes, which needs to be considered in mitigation strategies against wetland degradation and deterioration. Similarly, regarding wetlandscape ecohydrological characteristics, results indicated that there are variability between wetlandscapes of different sizes, where larger wetlandscapes showed features that can support ecosystem services to larger degree than small wetlandscapes. Large spatial variability in wetland ecohydrological characteristics was also seen within a wetlandscape. For instance, water storage dynamics and buffering capacity varied depending on the position of the wetland in the landscape. These differences in hydrological conditions were shown to result in different inundation dynamics between wetlands, which for instance also showed to impact insect community composition. Overall, this thesis shows that assessments of wetland ecosystem services need to be addressed using a wetlandscape approach, combined with actual on site hydrological measurements. The approach used in this thesis could help decrease uncertainties related to the impacts of hydro-climatic changes and anthropogenic pressures on wetlands and wetlandscapes, supporting location-specific wetland management strategies related to creation, restoration and sustainable use of wetlands and their ecosystems

Connecting Hydrological Processes to the Hypersaline Conditions of the Wetland Complex of Ciénaga Grande de Santa Marta, Colombia

Wetlands and coastal wetlands are important ecosystems for many aquatic and terrestrial flora and fauna as well as for the sustainable development of humans. Unfortunately, many of the world’s wetlands and coastal wetlands are subjected to degradation due to both natural processes and human activities changing the hydrodynamics of the area. As such, many coastal wetlands have been affected by hypersaline conditions consequently contributing to the degradation of both flora and fauna. This has also been true for the wetland complex of Ciénaga Grande de Santa Marta (CGSM), Colombia, where hypersalinity has been associated to constructions reducing freshwater inputs to the lagoon. As hydrological processes build up wetlands, it is crucial to understand how these processes impact wetlands and specifically the occurrence of hypersaline conditions. At the same time, not much is known about the hydrological conditions of wetlands, which is also the case for the wetland complex of CGSM. As such, this study focuses on disentangling the hydrological processes affecting the salinity levels of the wetland complex of CGSM by analysing the seasonal salinity patterns in both time (from the year of 2000 until 2015) and space. The analysis of the temporal pattern of salinity was also analysed statistically in relation to climatological data. The results from the temporal pattern of salinity showed a minor trend in increased salinity levels for the wetland in general, and by season, throughout the studied period. A rather strong correlation between salinity and climatological factors could also be identified. Moreover, the salinity for some areas within the wetland complex were higher during the wet season for some years,  compared to the dry season. The results from the spatial patterns of salinity showed that the salinity of the wetland was generally higher further away from the fresh water sources, by the outlet to the open sea, and especially for the area of Ciénaga de Ahuyama. The salinity patterns in space changed as the rain period started creating a division of the wetland complex into a high-salinity western area (main lagoon) and a low-salinity eastern area. This could be due to the relatively higher amount of fresh water inputs from rivers fed by precipitation on the mountains of Sierra Nevada de Santa Marta, east of the wetland complex,  compared to the relative small amount of freshwater from the channel of Aguas Negras in the western part of the wetland complex. Lack of correlation between salinity and channel dredging efforts questions the effectiveness of ongoing remediation strategies in the western section of the CGSM, while salinity levels in the eastern section are mainly regulated naturally via unrestricted freshwater inputs

Ecosystem services of wetlands and wetlandscapes under hydro-climatic change : Impacts of water flow and inundation patterns

Wetlands provide ecosystem services valuable for human society and are therefore often considered as nature based solution to different environmental problems. However, with centuries of wetland degradation due to anthropogenic pressures, such as agricultural expansion and forest industry, as well as pressures from climate change, there are large challenges for sustainable wetland management. Thus, for wetland protection and restoration practices to be successful, a deepened understanding on the actual mechanisms controlling wetland functions is required. Understanding how wetlands are connected, with and influenced, by their surrounding environment is also needed. Although most pressures experienced by wetlands operate on scales beyond the individual wetland scale, relatively few studies have thus far addressed large-scale functions and ecosystem service provision from hydrologically interconnected wetlands at the scale of wetlandscapes (i.e., the wetlands’ aggregated hydrological catchments in the landscape). The aim of this thesis is to investigate ecosystem service delivery from wetlands and wetlandscapes under hydro-climatic changes, considering 25 different wetlandscapes located in four different climate zones of the world. The thesis also systematically quantifies ecohydrological characteristics important for ecosystem service delivery and biodiversity support of wetlands and wetlandscapes in the Norrström Drainage basin located near Stockholm, Sweden.  Conducted hydro-climatic analyses showed that impacts of climate change on wetlandscapes cannot be fully understood from average changes in climatic variables of the climate zones within which the wetlandscapes are located. This may be due to the fact that wetlands are not randomly and evenly distributed within climate zones, but may be located in areas subject to stronger climatic changes than regional means. In addition, anthropogenic pressures were on average shown to have higher impacts on runoff in wetlandscapes in comparison to climate change. The pressures however showed relatively large variability between different wetlandscapes, which needs to be considered in mitigation strategies against wetland degradation and deterioration. Similarly, regarding wetlandscape ecohydrological characteristics, results indicated that there are variability between wetlandscapes of different sizes, where larger wetlandscapes showed features that can support ecosystem services to larger degree than small wetlandscapes. Large spatial variability in wetland ecohydrological characteristics was also seen within a wetlandscape. For instance, water storage dynamics and buffering capacity varied depending on the position of the wetland in the landscape. These differences in hydrological conditions were shown to result in different inundation dynamics between wetlands, which for instance also showed to impact insect community composition. Overall, this thesis shows that assessments of wetland ecosystem services need to be addressed using a wetlandscape approach, combined with actual on site hydrological measurements. The approach used in this thesis could help decrease uncertainties related to the impacts of hydro-climatic changes and anthropogenic pressures on wetlands and wetlandscapes, supporting location-specific wetland management strategies related to creation, restoration and sustainable use of wetlands and their ecosystems

Connecting Wetland Flooding Patterns to Insect Abundance Using High-Resolution Inundation Frequency Data

Flood dynamics are important drivers of wetland biodiversity. With current climate and land-use changes affecting overall water cycling, many wetland ecosystems are at risk of degradation, affecting biodiversity support negatively. This emphasizes a need for understanding possible correlations between specific hydrological conditions and biodiversity support in wetlands, at least in terms of species composition. In this study, we used high resolution hydrological monitoring of water levels and insect sampling in a depressional wetland to investigate possible correlations between inundation patterns and insect abundance. Our results show that there is a high spatial and temporal heterogeneity in wetland inundation patterns and that this heterogeneity explains variation in insect abundance. This creates episodes of downstream wet and upstream dry conditions. In addition, the spatial variability was high between grid cells of 2 meter’s resolution. There were also indications that distance to stream affected insect community structure. The findings from this work show that that the local hydrological conditions can create heterogeneity in habitat conditions, which in turn lead to refuge habitats for species vulnerable to changes in inundation condition. This study also highlights the importance of acknowledging quantitative hydrological methods when assessing the relation to insect communities.

Global assessment of accountability in water and sanitation services using GLAAS data

The Global Analysis and Assessment of Sanitation and Drinking-Water (GLAAS) is one of UN-Water’s regular reports. Its focuses include aspects of investment and the enabling environment for the delivery of water, sanitation and hygiene services. Accountability refers to the mechanisms through which duty bearers, elected officials and service providers report to rights holders and other stakeholders within the service delivery framework. Accountability contributes to good sector performance and the overall sustainability of services. The aim of this study was to evaluate the level of accountability in the drinking-water and sanitation sector globally, based on the available data from the GLAAS survey of 2014. To achieve this, accountability was defined from a human rights perspective, and particularised for water and sanitation. Next the quantitative and open-ended questions from the GLAAS survey that related to this definition were analysed for all 94 responding countries. Comparisons were drawn between water and sanitation services in urban and rural settings, and regional trends were identified. The results show higher levels of accountability for water than sanitation services, and limited information on wastewater. Potential means to strengthen accountability in water and sanitation globally are seen to include improving access to information on the services provided, enacting participation policies and increasing the capacity of regulatory institutions. Particular attention should be paid to rural services. The GLAAS survey could be modified for a better understanding of the accountability mechanisms for WASH service provision

Anlagda våtmarker som flödesbuffrare : Hur skapar vi synergieffekter medbiologisk mångfald och pollinering?

Anlagda våtmarker har använts som naturbaserade lösningar på miljöproblem sedan 1990-talet i Sverige, framför allt i jordbrukslandskapet. Inledningsvis var huvudsyftet kostnadseffektiva åtgärder för att minska övergödningseffekter i havet men även våtmarkers positiva effekt på den biologiska mångfalden betonades tidigt. Under det senaste decenniet har anlagda våtmarker också diskuterats som lösning på andra miljönyttor, som flödesbuffring, vattenmagasinering och för att hålla kvar kol i organogena marker. För de senare ekosystemtjänsterna är forskningsläget emellertid osäkert och för vissa, såsom flödesbuffring, har det saknats faktiska mätdata. Denna brist är speciellt tydligt på de större landskapsskalor som behöver studeras för att exempelvis förstå våtmarkers och våtmarkslandskapens förmåga att förhindra översvämning lokalt och av nedströms belägna områden. I frånvaro av mätdata har förväntade positiva effekter i stället modellerats fram genom att utgå från parametrar som nederbörd och avrinningsområdens egenskaper.  För att studera betydelsen av anlagda våtmarker i jordbrukslandskapet på flödesbuffring, dvs vattenmagasineringsförmågan, samt hur denna förmåga påverkar biologisk mångfald, har projektet samlat ett konsortium av experter och forskare inom framför allt ekologi och hydrologi. Inom ramen för projektet har en omfattande och strategisk provtagning genomförts under 3 år, av hydrologiska och ekologiska parametrar samt biologisk mångfald. Förutom dessa fältmätningar har även markägarnas åsikter kring värdet av sina anlagda våtmarker undersökts.  Resultaten visar att anlagda våtmarker i jordbrukslandskapet har en stor potential att fungera som flödesutjämnare och buffra vatten både i den enskilda våtmarken och på landskapsnivå. Samtidigt gynnas en stor mängd organismgrupper, inklusive specialiserade våtmarksarter på nationella hotlistor. Resultaten visar också att för både flödesbuffring och biologisk mångfald finns flera avgörande parametrar vad gäller placering och design som styr hur väl en våtmark faktiskt levererar dessa ekosystemtjänster.  De anlagda våtmarkerna i studien är huvudsakligen grävda dammar optimerade för näringsavskiljning och var därigenom relativt små och tog huvudsakligen emot dräneringsvatten från åkermark. Trots storleken bidrog de undersökta våtmarkerna till att dämpa högflöden med 3–17 %, vilket är i paritet med mätningar från natur­liga våtmarker i tidigare studier (cirka 10 %). Det visade sig också att våtmarkerna bibehöll sina buffrande funktioner både under kortare högflödesperioder samt under ett år med hög årsnederbörd, vilket indikerar att de kan fungera med liknande effektivitet i ett framtida klimat med högre avrinning. Vid extremnederbörd fram­står dock de buffrade volymerna i dessa små våtmarker som otillräckliga för att kunna fungera som (enskild) åtgärd, både idag och i framtiden.  Till skillnad från naturliga våtmarker fanns inga starka samband mellan flödesbuffringen i studiens anlagda våtmarker och deras position i avrinningsområdet. Varken våtmarkens höjd över havet eller nerströms/uppströms placering i avrinningsområdet påverkade buffringsförmågan. Det fanns dock andra faktorer som påverkade våtmarkernas buffring, som att buffringen ökade med storleken på våtmarkens tillrinningsområden. Den effekten var delvis oväntad eftersom våt­marker med stora tillrinningsområde borde fyllas snabbare, vara fulla under längre tid och därmed buffra mindre effektivt. Resultaten tyder dock på att den tekniska utformningen på våtmarkerna ger dem god buffringskapacitet trots hög hydrologisk belastning. Resultaten visar också att det finns marginal för att förbättra buffringen genom tekniska anläggningsmekanismer, särskilt i fråga om tömningsmöjligheterna och reglerbarheten i utloppskonstruktionerna. Våra data visar att endast 47 % av den teoretiska volymförändringspotentialen utnyttjades i våtmarkerna, vilket kan medge ökad buffringspotential genom aktiv tömning/sänkning inför stora neder­bördssituationer.  De kraftiga vattennivåvariationerna i många av våtmarkerna, i kombination med förekomst av både flacka partier och brantare släntlutning, var positivt för artrikedomen hos flera organismgrupper. Generellt gynnades mångfalden hos flera grupper av större strandvåtmarker och flacka stränder, men det fanns undantag. Till exempel gynnades nätbyggande spindlar av brantare stränder. Ett oväntat resultat var också den begränsade eller till och med negativa effekten av betande djur, vilket går stick i stäv med rekommendationer i manualer för våtmarksanlägg­ning och skötsel. Sannolikt gynnas leddjuren av att vegetationen hålls kort men samtidigt kan de rent fysiska effekterna av trampet missgynna artgrupper som har sin larvutveckling i blöt jord. För att förstå dessa samband behövs mer forskning som går in på mekanismer samt hur effekten påverkas av djurslag, djurtäthet och jordart. För insekter som utvecklas i vatten, som trollsländor, sågs inga samband med hydrologiska parametrar, men det var uppenbart att små, anlagda våtmarker är veritabla artöar för trollsländor. Totalt noterades 68 % av alla Sveriges arter på en yta (800 km2) som motsvarar 0,0015 % av Sveriges yta. Artsammansättning skilde sig mellan våtmarker och för att nå höga artantal på landskapsnivå kan det därför vara en fördel med många olika våtmarker i en region. För pollinatörer, särskilt bin, fanns korrelation mellan förekomst och storleken på våtmarkernas minsta vattenareal (dvs, när de är som mest uttorkade).  Markägarenkäten visade att markägarna överlag ser mest nyttor, snarare än problem, med anlagda våtmarker. Mest notabelt var den höga nöjdheten med våtmarker (91 %) samt att en mycket stor andel markägare (83 %) använder sin våtmark för personlig rekreation, där skridskoåkning var populärast.  Slutsatsen från studierna är att anlagda våtmarker som konstruerats för närings­avskiljning och i viss mån biologisk mångfald kan fungera bra som flödesbuffrare. Dessutom finns stor potential för ökad buffringskapacitet genom att både utform­ning (inte minst in- och utloppslösningar och aktiv nivåstyrning i våtmarkerna), läge och skötsel har en stor påverkan på den totala effekten. Dessutom verkar det finnas möjliga synergieffekter mellan vattennivåvariationer och artrikedomen av leddjur, men för att nå en hög biologisk mångfald i anlagda våtmarker bör stränderna vara heterogena eller att olika våtmarker har olika struktur