Riverine landscapes: Biodiversity patterns, disturbance regimes, and aquatic conservation

“There are reports that freshwater ecosystems are faced with higher threats and risks of destruction than any other major world ecosystems (Allan and Flecker, 1993; Ward, 1998) and that globally freshwater fauna faces high risks of extinction (Richter et al., 1997).”

“Watershed management is a complex issue, requiring information on a diversity of variables, including both terrestrial and aquatic ecosystem components (Ward, 1998).”

“…has led to an increased view of rivers as spatially continuous lateral and longitudinal mosaics with rich heterogeneity resulting from linked physical-biological processes acting at a range of scales [Schlosser, 1991, Ward, 1998, Fausch et al., 2002, Wiens, 2002, Carbonneau et al., 2012].”

“…= -0,0595x + 9,6685 R² = 0,9814 0 0,5 1 1,5 2 2,5 3 3,5 6080100120140160180200 62 holística producto de la extensa serie interconectada de biotipos y gradientes ambientales que, con sus comunidades bióticas, constituyen en sí los sistemas fluviales (Ward, 1998).”

“Therefore, negative human impacts happening on land can influence surrounding river systems via spatial flows of organisms, resources, and pollutants (Birk et al., 2020; N ˜ oges et al., 2016; Ward, 1998).”

“This framing conceptualizes fluvial environments as heterogenous, multiscale and multidimensional systems that dynamically adjust in space and time (Fausch et al. 2002; Torgersen et al. 2022; Ward 1998; Wheaton et al. 2019).”

“Landscape disturbance associated with land use has negatively affected stream habitat (e.g. reductions in water quality and degradation) and altered the structure and function of many ecosystems (Allan, 2004; Maloney & Weller, 2011; Ward, 1998).”

“This phenomenon has been widely reported in ecological literature for both fish and macroinvertebrates (Minshall et al. 1985; Ward 1998; Paller et al. 2006) and implies there is a threshold in stream size after which richness can be expected to plateau or decrease with increasing streamflow.”

“Dependiendo del orden del río puede tener impactos en las llanuras de inun-dación, lo que influye en vegetación ribereña, la disminución de microhábitats y afectaciones en los ciclos biológicos de especies acuáticas nativas (Kondolf, 1997; Ward, 1998; García de Jalón, 2008).”

“, 1989), river science (Ward, 1998; Latterell et al., 2006; Thorp et al., 2006), as well as in biogeomorphology (Phillips, 1995; Bouma et al.”

“There is international concern for the loss of biodiversity (Simberloff 1998; Sotherton 1998; Suter 1998; Ward 1998; Cabeza and Moilanen 2006; Garden et al. 2006), particularly associated with habitat fragments in the periurban context (Buxton et al.”

“Therefore, a high richness of phytoplankton taxa is expected, especially in its middle stretch, where all these scenarios coexist (Vannote et al., 1980; Ward, 1998; Tockner et al., 2002).”

“Open riparian habitats are more strongly affected by solar radiation and wind effects resulting in higher ambient soil and instream water temperatures and lower relative humidity (Moore et al. 2005).”

“According to the River Continuum Concept, the longitudinal (upstream– downstream) biodiversity pattern forms in response to continuous changes in environmental conditions (RCC; Ward, 1989; Ward, 1998; Vannote et al., 1980).”

“Large rivers are dynamic systems with high variability in spatio-temporal physicochemical characteristics and biotic assemblages [4].”

“For most rivers of intermediate size, this translates into 48 an increasing pattern of α-diversity in the downstream direction, which has been validated empirically 49 [Ward, 1998], in particular for fish [Muneepeerakul et al.”

“As a result, most rivers lost their natural dynamics and patterns with a consequent decline in habitat and species diversity (Ward 1998, Buijse et al. 2002, Pedroli et al. 2002, Lorenz et al. 2009, Tockner et al. 2009, Hauer et al. 2016).”

“Low values of standard deviations indicate more stable habitat conditions which favour taxonomic diversity (Ward, 1998; Gallardo et al., 2008; Obolewski, 2011a; Obolewski & Glińska-Lewczuk, 2011).”

“Regardless of size or type, all floodplains rely on inundation from high flows of adjoining waterways (Junk et al., 1989; Walker et al., 1995; Ward, 1998) and have spatial and temporal complexity that makes them amongst the most dynamic ecosystems on earth (Kingsford, 2000).”

“The connections are equally manifested in a longitudinal (between river reaches or between tributaries and the trunk river), horizontal (slopes-floodplain-channel) as well as vertical sense (channel-groundwater) (Ward, 1997).”

“Expanding the view of the stream in a landscape ecology approach helped organize large complex systems (Frissel et al., 1986 ; Wu and Loucks, 1995; Ward, 1998; Weins, 2002; Naiman et al., 2005; Thorp et al., 2008).”

“,1980), biodiversity should exhibit a unimodal pattern (Vannote & Sweeney, 1980; Ward, 1998) with maximum values in the middle reaches (stream order 4 or 5).”

“Habitat Intrinsic Potential The findings from this study corroborate with the working hypothesis set forth by Steel (2003) and Ward (1998) that landscape characteristics affect stream habitat and thus affect salmonid populations.”

“…(Xia et al. 2018; Xu et al. 2024) or natural disturbances associated to the riverbank like erosion or flooding, both of which are more frequent and intense in this zone (Ward 1998; Abernethy and Willby 1999; Nakamura et al. 2000; Lite et al. 2005; Formann et al. 2014; Sharpe and Kemp 2021).”

“Oxbow lakes belong to ecosystems that can persist for centuries and millennia, playing a vital role as habitat for many species of fauna and fl ora and storage of pollutants in fl oodplains (Thomas et al., 2022; Tockner and Stanford, 2002; Ward, 1998).”

“This understanding emphasizes that the success of conservation strategies often hinges on fostering synergies be-tween flora and fish populations, essential for achieving long-term ecological stability and resilience in freshwater environments (Ward 1998; Lyons et al. 2005).”

“…Giese (Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA) and Lisa A. Schulte (Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA) O xbow lakes are among the most biologically diverse aquatic systems in the world (Ward 1988).”

“In natural alluvial landscapes, the extension of wetlands is influenced by many factors such as the hydrological cycle, the landscape morphology and the riverine regime, which can lead wetlands to evolve into terrestrial environments (Ward, 1997).”

“Whereas, episodic disturbances from climatically driven high-flow events tend to reset successional stages in riverscapes and regulate aquatic food webs by decreasing abundance of predator-resistant primary consumers that support diverse food chains (Ward 1998; Power et al. 2013).”

“The focus on solving spatial relationships in the landscape culminated with the development of the concept of habitat continuity (Ward, 1998), which received considerable attention in terrestrial landscape ecology.”

“Aquatic ecosystems are particularly affected by anthropogenic impacts (Dudgeon et al., 2006; Richter, Braun, Mendelson, & Master, 1997; Sand-Jensen, Riis, Vestergaard, & Larsen, 2000; Ward, 1998).”

“To deal with the greater demands on the world’s freshwater barriers are constructed for power generation, flood control and irrigation, resulting in degradation of river ecosystems [1,2,3,4].”

“It not only disturbs the riparian vegetation by its scouring effect (Brown and Peet, 2003; Ward, 1998), but also brings great quantities of sediments (Davis et al., 2000; Tabacchi et al., 1998), as well as numerous propagules (Fraaije et al., 2015; Holle and Simberloff, 2005) from the upstream…”

“These changes not only affect water quality but also modify riparian landscapes, increasing the input of agrochemicals into aquatic systems and posing severe risks to biodiversity and ecological processes (Ward 1998; Townsend et al. 2003; Viglizzo et al. 2003; Allan 2004).”

“Freshwater fishes depend on rivers or lakes for survival and are facing a greater potential for extinction than terrestrial and marine species (Ward, 1998).”

“These populations also show regional stenotopy, linked to specific biotopes at the northern limit of the species distribution, and occur sympatrically with other animal and plant species con - nected with the river phenomenon (Ward 1998; Chmelař et al. 2023).”

“Assim, as perturbações em conjunto aos gradientes ambientais podem agir positivamente entre a conectividade e a heterogeneidade espaço-temporal, elevando a riqueza biológica local (Ward, 1998).”

“The most well-known modifications are channel fixing and expulsion of riparian vegetation (Naiman and Décamps, 1997; Ward, 1998).”

“Most large rivers of Europe and Central Asia have suffered from flow regulation and human activities (Dynesius & Nilsson 1994; Ward 1998), and temporary pools have disappeared dramatically as a result of agriculture intensification and urbanization (Bouahim et al.”

“83 In floodplains like the Pantanal, the flood pulses drive important seasonal ecosystem 84 changes [9, 10], activating ecological processes that control both the spatial and temporal 85 distribution of organisms as well as their life-history strategies.”

“These floods are capable of uprooting trees and shrubs, moving boulders in the riverbed and creating large habitat structures such as oxbow lakes (Ward 1998).”

“Biodiversity patterns are directly and indirectly influenced by the gcornorphology of riverine landscapes (WARD, 1998).”

“Ward and Tockner (2001) recognised a range of major environments in river corridors that contribute biodiversity to lotic ecosystems (Fig.”

“However, freshwater fishes and their ecosystems are among the most threatened fishes and ecosystems in the World (Ward, 1998; Malmqvist and Rundle, 2002; Dudgeon and others, 2006).”

“Less flooding reduces these interactions decreasing the species diversity and heterogeneity in the floodplain (Ward, 1998).”

“Aquatic ecosystems include their often extensive and interconnected riparian zones within environmental gradients that cross spatiotemporal scales (Ward 1998).”

“Starting in the 1960s, most streams have been modified through the creation of straight, artificial channels, and levees, designed to control flood water movement and flooding (Ward, 1998; Woo, 2010).”

“Riparian zones interact with the surface water, sub-surface water, and the land, shaping the riverine ecosystem (Thorp et al. 2008; Ward 1998).”

“Rivers and their riparian zones together form longitudinal ecotones that link terrestrial and running-water ecosystems where the wetted river channel interacts through fluvial and ecological processes with the surrounding catchment (Ward 1998; Ward et al. 2002).”

“Lowland fluvial oxbow lakes and their riparian zones are integral floodplain habitats provid - ing key ecosystem services, including water quality maintenance, biodiversity support, and carbon sequestration (Ward 1998; Naiman et al. 2010; Graziano et al. 2022 ; Das et al. 2025 ).”

“In the face of increasing pressure on freshwater resources, it is necessary to protect the ecological integrity and biodiversity of aquatic systems (Richter et al., 1997; Ward, 1998).”

“According to Ward (1998), riverine landscapes are made up of a mosaic of interrelated habitats and environmental variances, which constitute an interconnected system that supports both spatial and temporal ecological functions.”

“It is well understood that hydrological and geomorphological processes produce physical patterns in riverine landscapes at multiple spatial and temporal scales (Frissell et al. 1986, Ward 1998).”

“Floodplain ecosystems host a mosaic of lotic, lentic, ephemeral, and semi-aquatic water bodies with dynamic hydrological connections among them that provide complex, diverse habitats for a variety of plant and animal species (Ward 1998, Thomaz et al. 2007).”

“…dynamics and to reconstruct a channel of free lateral migration of the river across its floodplain, which seems the most robust approach to preserve self-renewing early successional riparian habitats in the long term (Ward, 1998; Gröning et al., 2007; Kästner, 2011; Pawlaczyk, 2017; EEA, 2019).”

“It is possible that Sickle Darters move differently in these subbasins due to each sub-basin’s unique riverine features, size, and amount of available habitat (Ward, 1998).”

“Ce type de milieu humide riverain (Ward 1998) n’est pas inondé pendant la très grande majorité de la saison de croissance, permettant la baisse naturelle du niveau de la nappe phréatique et le développement de peuplements forestiers.”

“Složení, uspořádání a stupeň hydrologické propojenosti těchto biotopů určuje stabilitu vodního prostředí a ekosystémové procesy [17, 18].”

“The geomorphology of the riverine scenery in one way or another affect biodiversity pattern [9].”