Exploring Nature-Based Solutions for Urban River Restoration: Insights from China's Sponge City Programme

In cities, river restoration is widely recognised as an essential Nature-based Solution (NbS) that delivers a wide range of benefits. However, rapid urbanisation and economic growth over the past four decades have led to the degradation of Chinese rivers. In response, the Chinese government introduced the Sponge City (SC) concept in 2013 as part of the 'Ecological Civilisation' era. The SC, considered a hybrid NbS, was designed to foster urban resilience, particularly against severe disasters such as floods. The nationwide SC Program (SCP) commenced in 2014. Since then, the number of participating cities has continued to grow. As a result, a large number of Chinese cities have been transitioning from traditional grey infrastructure to green/blue infrastructure with substantial investments, leading to the restoration, redesign and revitalization of urban rivers. Despite these efforts, there is a noticeable lack of research that examines urban river restoration from a multi-beneficial NbS perspective, a current global research trend. To address this research gap, the present study adopted a mixed-methods approach, combining expert interviews with bibliometric analysis, to explore the specific role of urban rivers as an NbS within the SC framework. Our study revealed an increasing scientific interest in urban river restoration beginning in 2013, viewing them as elements of sponge construction. Alongside this, there's a progressively nuanced understanding of rivers as multifunctional NbS. In addition, we identified specific challenges that impede the successful implementation of these NbS in Chinese cities. To overcome these barriers, we formulated a set of recommendations that are in harmony with China's new River Chief System policy and the Ecology Oriented Development (EOD) model. The aim is to enhance the sustainable governance of urban rivers as an NbS in the long term, thus contributing to overall sustainable development in China

Introduction

Introduction Établie en 2014 auprès de l’Université François-Rabelais de Tours, en partenariat avec l’Université d’Angers et la Mission Val de Loire, la Chaire Unesco « Fleuves et patrimoine/River Culture », est un dispositif académique qui vise à favoriser les collaborations scientifiques et pédagogiques autour de la thématique des espaces fluviaux, de leur diversité biologique, culturelle et paysagère (www.unesco-chair-river-culture.eu..

Increased geographical distribution and richness of non-native freshwater fish species in Argentina: evidence from a literature review

The present study is a full review of the non-native freshwater fish species introduced into Argentina and their relationship to the main environmental features and introduction vectors of each freshwater ecoregion. The total number of non-native freshwater fish species was compiled through a literature survey; information on spatial–temporal patterns of species records and invasion vectors was retrieved for all ten freshwater ecoregions of Argentina. Our survey revealed that 18–22 non-native fish species had been recorded up to 1999, and a total of 40 introduced fish species, of which 18 are invasive and five potentially invasive, had been registered in seven Argentinean ecoregions as of May 2020. According to georeferenced records, the rainbow trout Oncorhynchus mykiss and common carp Cyprinus carpio were the non-native fish species with the greatest number of records and largest invaded areas, probably due to their species-specific ecological traits. Invasive fish species differed clearly between the Patagonia, Lower Paraná, and Lower Uruguay ecoregions, probably because of a combination of the environmental conditions, structure of native assemblages, and invasion pathways in each ecoregion. Except for the recognized impact of non-native salmonids, the adverse effects of introduced fish species have been little studied, indicating the need for further research to clarify the role of ecological shifts triggered by the introduction and establishment of non-native fish species in Argentina. In contrast to the high diversity of aquatic species and freshwater environments, the spread and impact of invasive fish species in Argentina is little known, particularly compared with other South American countries.Fil: Espínola, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Rabuffetti, Ana Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Carrara, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Abrial, Elie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Ferlay, Elise Mathilde Charlotte. Polytechnic School Of The University Of Tours; FranciaFil: Yoya, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Blettler, Martin Cesar Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Baigún, Claudio Rafael M.. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Wantzen, Karl Matthias. Centre National de la Recherche Scientifique; FranciaFil: Neves dos Santos, Luciano. Universidade Federal do Estado do Rio de Janeiro; Brasi

Cerrado streams - characteristics of a threatened freshwater ecosystem type on the Tertiary Shields of Central South America

Cerrado is a seasonal savanna type covering 20% of the Brazilian territory, however in large areas its vegetation has been replaced by agriculture. The high plains of the Central Brazilian Shield are incised by a large number of stream valleys. In spite of their small individual size, the extension of the stream valleys is estimated to 5% of the total Cerrado area. Apart from their geographical occurrence, Cerrado streams are characterized by extremely low conductivity, weak buffering capacity and variable pH values which are a consequence of the ion poverty of the soils. The hydrographs show very stable patterns during the dry season and frequently recurring flashfloods during the rainy season. The biota of Cerrado streams reveal a range of characteristics such as a reduced proportion of shredding invertebrates, large numbers of predators, and high resistance and resilience to spates. Species traits of aquatic insects include adaptations such as small body size, polivoltine life cycles and the synchronous occurrence of different larval stages. These features make them interesting objects for the development and testing of new stream concepts. On the other hand, the biota and habitat structures are highly sensitive to inputs of inorganic sediments from erosion gullies which threaten literally all Cerrado streams in the agricultural landscapes of Mato Gross

Tropische Feuchtgebiete und ihre klimatische Bedeutung am Beispiel des Pantanals

Feuchtgebiete kommen auf der ganzen Welt vor. In den Tropengebieten sind sie, je nach Höhe und Regelmäßigkeit der Überschwemmung und Bodenart, als dichte Wälder, offene Savannen oder als Sümpfe und extensive Moore ausgeprägt. Die Dauer der Feuchtigkeitsphase ist von entscheidender Bedeutung für die Bodenbildung und für die vorherrschende Vegetation. Tropische Feuchtgebiete bilden häufig große, zusammenhängende Flächen und tragen wesentlich zum globalen Wasserhaushalt bei. Sie stehen miteinander in Verbindung, über Seen und Flüsse oder auch indirekt über das Grundwasser. Die dem Schutz der Feuchtgebiete gewidmete Ramsar-Konvention weist darauf hin, dass intakte Feuchtgebiete der Garant für die Abflussbildung in Bächen und Flüssen (und damit auch für unser Trinkwasser) sind. Aufgrund der stetig hohen tropischen Temperaturen kommt Feuchtgebieten eine Sonderrolle im globalen Klima zu. Da die biochemischen Prozesse dort schneller ablaufen als in höheren Breiten, wird organische Substanz zumeist rasch umgesetzt, was zu einer geringen Bodenbildung führt. Dies ist v.a. beim Phasenwechsel zwischen feuchten und trockenen Bedingungen der Fall, der sehr rasch erfolgen und durch menschliche Aktivitäten stark beeinflußt werden kann. Während längerer Überschwemmungsphasen hingegen entstehen anoxische Bedingungen in den Sedimenten, welche die Mineralisierung von organischer Substanz stark verringern, aber auch die Methanbildung fördern. Daher können tropische Feuchtgebiete in der Summe abwechselnd Kohlenstoffsenken und -quellen sein. Für saisonale neotropische Feuchtgebiete wurde die Überschwemmungsdauer von etwa 250 Tagen pro Jahr als »Schalter« identifiziert. In längeren Feuchteperioden speichert das System Kohlenstoff, in kürzeren Perioden setzt es Kohlenstoff frei. Tropical wetlands and their climatic significance using the example of the Pantanal: Wetlands occur all over the world. In the tropical regions, depending on the level and regularity of the flooding and the type of soil, they are pronounced as dense forests, open savannas or as swamps and extensive moors. The duration of the moisture phase is of decisive importance for soil formation and for the prevailing vegetation. Tropical wetlands often form large, contiguous areas and contribute significantly to the global water balance. They are connected to one another, via lakes and rivers or indirectly, via the groundwater. The Ramsar Convention, which is dedicated to the protection of wetlands, points out that intact wetlands are the guarantee for the formation of runoff in streams and rivers (and thus also for our top water). Due to the constantly high temperatures, tropical wetlands play a special role in the global climate. Since the biochemical processes take place there faster than at higher latitudes, organic matter is usually converted quickly, which leads to less soil formation. This is especially the case with the phase change between wet and dry conditions, which can take place very quickly and can be strongly influenced by human activities. During longer periods of flooding, however, anoxic conditions arise in the sediments, which greatly reduce the mineralization of organic matter, but also promote methane formation. Therefore, tropical wetlands can alternately be net carbon sinks oder carbon sources. For seasonal neotropical wetlands, the flood duration of around 250 days per year has been identified as a »switch«. In longer periods of humidity the system stores carbon, in shorter periods it releases carbon. Los humedales tropicales y su importancia climática utilizando el ejemplo del Pantanal: Los humedales se encuentran en todas las regiones del mundo. En las regiones tropicales, según el nivel y la regularidad de las inundaciones y el tipo de suelo, se manifiestan como bosques densos, sabanas abiertas o como pantanos y páramos extensos. La duración de la fase de humedad es de importancia decisiva para la formación del suelo y para la vegetación predominante. Los humedales tropicales a menudo forman áreas grandes y contiguas y contribuyen significativamente al balance hídrico global. Están conectados entre sí, a través de lagos y ríos o indirectamente, a través de las aguas subterráneas. La Convención de Ramsar, dedicada a la protección de los humedales, señala reiteradamente que los humedales intactos son garantía para la formación de escorrentías en arroyos y ríos (y por lo tanto también para nuestra agua potable). Debido a las constantemente elevadas temperaturas tropicales, los humedales juegan un papel especial en el clima global. Dado que los procesos bioquímicos tienen lugar allí más rápido que en latitudes más altas, la materia orgánica generalmente se convierte rápidamente, lo que conduce a una menor formación de suelo. Este es especialmente el caso del cambio de fase entre condiciones húmedas y secas, que puede tener lugar muy rápidamente y puede verse fuertemente influenciado por las actividades humanas. Durante períodos más largos de inundaciones, por otro lado, surgen condiciones anóxicas en los sedimentos, que reducen en gran medida la mineralización de la materia orgánica, pero también promueven la formación de metano. Así, en conjunto, los humedales tropicales pueden alternar entre sumideros y fuentes de carbono. Para los humedales neotropicales estacionales, la duración de la inundación de alrededor de 250 días por año se ha identificado como un »limite«. En períodos más largos de humedad, el sistema almacena carbono, en períodos más cortos libera carbono

Threats Underestimated in Freshwater Plastic Pollution: Mini-Review

Plastic pollution is one of the most acute environmental topics of our time. While there is a great scientific effort to tackle this problem, it has not always been well-coordinated or properly targeted. In this short review, we call for scientists to get involved in three crucial topics (threats) underestimated?or ignored?in freshwater systems: (i) plastic-species entanglement, (ii) plastic as nesting material, and (iii) macroplastic debris coming from mismanaged household solid waste. Reducing the knowledge gaps between marine and freshwater environments will be crucial to solute the plastic pollution problem effectively and globally. Therefore, we make a plea here to reinforce research activities on these three issues in freshwater environments worldwide.Fil: Blettler, Martin Cesar Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Wantzen, Karl Matthias. Centre National de la Recherche Scientifique; Francia. Tour University; Franci