Riparian Habitat Quality Research Articles

Riparian habitat quality as an indicator of land use/land cover effects on riverine water quality

Riparian land use/land cover (LULC) plays a crucial role in maintaining riverine water quality by altering the transport of pollutants and nutrients. Nevertheless, establishing a direct relationship between water quality and LULC is challenging due to the multi-indicator nature of both factors. Water quality encompasses a multitude of physical, chemical, and biological parameters, while LULC represents a diverse array of land use types. Riparian habitat quality (RHQ) serves as an indicator of LULC. Yet, it remains to be seen whether RHQ can act as a proxy of LULC for assessing the impact of LULC on riverine water quality. This study examines the interplay between RHQ, LULC and water quality, and develops a comprehensive indicator to predict water quality. We measured several water quality parameters, including pH (potential of hydrogen), TN (total nitrogen), TP (total phosphorus), Twater (water temperature), DO (dissolved oxygen), and EC (electrical conductivity) of the Yue and Jinshui Rivers draining to the Han River during 2016, 2017 and 2018. The water quality index (WQI) was further calculated. RHQ is assessed by the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model. Our study found noticeable seasonal differences in water quality, with a higher WQI observed in the dry season. The RHQ was strongly correlated with LULC compositions. RHQ positively correlated with WQI, and DO concentration and vegetation land were negatively correlated with Twater, TN, TP, EC, cropland, and construction land. These correlations were stronger in the rainy season. Human-dominated land, such as construction land and cropland, significantly contributed to water quality degradation, whereas vegetation promoted water quality. Regression models showed that the RHQ explained variations in WQI better than LULC types. Our study concludes that RHQ is a new and comprehensive indicator for predicting the dynamics of riverine water quality.

Assessment of Riparian Ecosystem Health in the Tamiang River, Aceh, Indonesia as Remains Habitat of Batagur borneoensis (Schlegel & Muller, 1844)

The riparian zone along the Tamiang River, Aceh Province, is an important habitat for the survival of the tuntong laut (Batagur borneoensis) which is already threatened with extinction. This study aims to evaluate the quality and role of the riparian zone as a habitat for B. borneoensis along the Tamiang River, which can then be used as a reference in conservation. Riparian habitat quality was assessed by calculating the Qualitat del Bosc de Ribera (QBR) index, which was determined based on the total riparian cover, cover structure, cover quality, and channel alteration. In addition, observations of water quality (salinity, turbidity, and dissolved oxygen (DO)) and the number of riparian vegetation species were also carried out. Monitoring was carried out at five stations: Iyu River, Kampung Baru, Batang Lawang, Pusong Kapal Dermaga, and Pusong Kapal. The results showed variations in water quality between locations with DO and turbidity levels exceeding the quality standards set by the government. The richness of the types of riparian vegetation found ranged from 0-8 species (seedlings), 2-7 species (saplings), and 1-4 species (poles). The quality of riparian habitats in all study locations experienced significant degradation, including the euhemerobic and polyhemerobic (Hemeroby) categories, Cultural assisted system and Semi-transformed system (Naturalness), and Extreme degradation to poor-fair quality (QBR). The presence of B. borneoensis in the research location can adapt to the poor quality of riparian habitat. However, the density decreases significantly at higher salinity.

Quality of riparian habitat and its influence on water quality in some ecosystems of waterfalls and springs in Bawean Island

This study aims to evaluate the quality of riparian habitats based on the index of riparian quality (QBR), quality of riparian tree vegetation (community structure and Naturalness index), and anthropogenic activity (Hemeroby Index) and their relationship to water quality in some waterfall and spring ecosystems on Bawean Island. This Ex Post Facto study was conducted on six waterfall ecosystems (Candi, Putri, Suwari, Talomon, Laccar and Kuduk Kuduk) and two spring water ecosystems (Kuduk Kuduk and Laccar). Analysis of riparian tree vegetation at each location was observed from three plots with size 50 x 50 m2. The physics chemical quality of water observed at each location included pH, dissolved oxygen/DO, total suspended solid/TSS, total Kjeldahl nitrogen/TKN, and biochemical oxygen demand/BOD. The results showed that the quality of the riparian habitat affected the water quality.

Evaluation of aquatic ecological health of sluice-controlled rivers in Huai River Basin (China) using evaluation index system.

The aquatic ecological health status was focused on the Huai River Basin (HRB) from the aspects of water quantity, water quality, water ecology, river connectivity, and riparian habitat environment. Ten monitoring sections were set up in the middle and upper reaches of HRB, and 5 experiments of each section were conducted in July and December from 2012 to 2014. Thus, relevant data on the species, the density of phytoplankton, zooplankton and benthic animals, the concentration of water physicochemical variables, and riparian habitat quality were obtained. Eleven key impact factors were chosen using frequency statistics, theoretical analysis, and correlation analysis methods, forming the evaluation index system of aquatic ecological health. Then, the indicator weight value was determined by the combined weight method, and the health degree was evaluated by the comprehensive index method. On the whole, the aquatic ecological health degree of the upper sections (D1 ~ D3) of the Shaying River ranges from 0.334 to 0.927, which is generally in a "sub-healthy" state. The aquatic ecological health degree of the main section of the Huai River (D8 ~ D10) ranges from 0.362 to 0.777, which is in the "critical" or "sub-healthy" state. The Huaidian Sluice (D5) and Fuyang Sluice (D6) in the middle and lower reaches of the Shaying River had the worst aquatic ecological health. Its water ecological health range is 0.283-0.523, and most of them are under "sub-pathologic." The research results have important theoretical and practical significance. They can enrich the evaluation theories and methods of river aquatic ecological health, help to grasp the aquatic ecological health status in HRB, and provide basic support for aquatic ecological protection and water pollution control in sluice-controlled rivers.

Ecological challenges* for the use of soil and water bioengineering techniques in river and coastal engineering projects

A major challenge for the modern river and coastal management is a holistic design approach in order to integrate flood and erosion protection combined with ecological restoration. Nowadays, a lot of EU regulations request nature-based engineering solutions such as soil and water bioengineering techniques (SWBE). In contrast to conventional ‘hard’ civil engineering structures, the idea of SWBE structures is the use of biological components in the engineering structure to not just consider a technical function, but also ecological and aesthetic values. While SWBE techniques are applied worldwide and well established as an engineering discipline, there is a high demand on the further development specifically in terms of ecology.The use of plants in river engineering projects requires the right choice of species depending on the techniques used and the environmental conditions. Furthermore, a right harvest, storage and implementation of the plants is significant. Their use also requires the quantification of the hydraulic and sedimentological impact of riparian vegetation on the one hand and on the other hand to know the impact of SWBE structures on the aquatic and terrestrial habitats. Different ecological, vegetational and phytosociological criterias are available and discussed in terms of assessment of SWBE structures. All these criteria can be helpful to develop a framework supporting stakeholders to define objectives, design, implementation work and to assess the post-construction lifetime phase, which is most relevant for SWBE structures. From a wider point of view, when looking at the multitaxonomic diversity in both terrestrial and aquatic habitats, it has been shown that SWBE techniques could enhance global riparian habitat quality by allowing a greater richness and density of pioneer tree species. The use of phytosociology has become more important for the application of SWBE structures as nature-based vegetation composition. Specific challenges arise for river managers and practitioners with invasive alien species and climate change forcing us to redefine what is meant by ‘non-native’ species. Therefore, using a local and historical phytosociological typology to define the reference to be achieved could become increasingly misleading. By analyzing the ecological value of SWBE structures, another aspect must be considered from an ecological point of view. The possible negative impacts on ecosystems caused by SWBE measures, during the period of construction (e.g., emissions, energy consumption, intervention in nature) should be taken into consideration. A popular methodology to provide the possibility of achieving a better understanding of environmental burdens and to assess the potential environmental impact of products or services is environmental life cycle assessment (LCA). We are faced with the problems of climate change which means that we have to optimize our civil engineering (including SWBE) construction activities in terms of positive effects, for example urban heat islands or carbon storage and also any potential negative effects, for example emission of greenhouse gases or energy demand.We must critically examine our model of the SWBE approach, the application of SWBE techniques does not automatically mean an ecological improvement. SWBE systems are dynamic and always different, depending on their field of application. A harmonization of strategies and goals needs to be developed in order to support coherent measures aimed at improving the ecological status of river bodies, coastal areas and at the same time, guaranteeing hydraulic safety and adequate protection of human activities from hydromorphological hazards (flooding, floodplain erosion, failure of river and coastal-related infrastructures).

Hydromorphological assessment in North Morocco: The case of Martil River

The present study is about an assessment of the Martil River restoration, which crosses Tetouan and Martil city in Northern Morocco. The evaluation compromises rainfall occurrence of 30 years, riparian habitats, and the river flow of 12 years. The rainfall analysis was carried out by the Standard Precipitation Index (SPI). Only three stations that contain continuous monthly precipitation data were considered. The river health and water quality were determined by the QBR (Riparian Habitat Quality), while the environmental flow was estimated by Tennant method. SPI results show a rainfall increment pattern with regular, extreme, and plentiful downpours causing rough deluges and floods. The ultimate flow result to support the river habitats was found 60% of the natural flow in the main channel. This study highlights the stream’s unhealthy water, which falls within the low-quality water category downstream the river under anthropogenic pressure, while good to excellent quality was scored upstream the watershed. Tennant outcomes were discovered 2.40 m³/s as 30% and 5.51 m³/s as 60%, while 10% of the flow was found to be not adequate for habitats in the Martil River.

Using an ecosystem services approach to re-frame the management of flow constraints in a major regulated river basin

ABSTRACT Worldwide, floodplains have been alienated from river channels for flood protection and water resource development, but several recent programs have restored connectivity, generating considerable ecological and , socio-economic benefits. In Australia, under the Murray-Darling Basin Plan, water purchased from irrigators is used to restore wetlands. Maximising ecological benefits with limited water requires constraints relaxation, whereby high flow volumes for ecologically effective floods are released from headwater dams and allowed to flood public and private land en route to wetlands downstream, requiring infrastructure works and rights to inundate private land. We examined five focal areas in the Basin Constraints Management Strategy to determine ecosystem services benefits generated by floods on land between dams and target wetlands We found multiple examples where significant co-benefits could be realised but had not been identified. Accordingly, the assessment of costs and benefits was primarily focussed on costs. We categorised ecosystem services for each focal area as of low, medium or high importance andassigned monetary values where possible. Regulating and cultural services, rather than provisioning services, ranked highest across all focus areas, including groundwater recharge, regulation of riparian habitat quality, aesthetic appreciation, recreation and tourism, Indigenous and community values. The business cases seek to maximise costs and thus the transfer of public funds in compensation to landholders. However, there are important public policy considerations of equity, accountability and transparency, including proof of damage prior to compensation, as well as offsetting losses against ecosystem services benefits. We consider that an ecosystem services approach could greatly improve acceptance of constraints relaxation amongst landholders and the development of novel policy options and instruments that can help advance the implementation of the Basin Plan.

A Multivariate Approach to the Selection and Validation of Reference Conditions in KwaZulu-Natal Rivers, South Africa

The use of reference conditions is essential to the monitoring and management of aquatic ecosystems. We examined existing and potential reference sites through historical data, maps and field data collected from river sites in KwaZulu-Natal (KZN), South Africa. In our study, we applied nine criteria that best reflect the characteristics of South African rivers on 24 a priori selected reference sites. These nine criteria comprised of catchment conditions (flow modification and natural landscape) and site-specific attributes (water quality, human disturbance, river channel, water abstraction, riparian vegetation, riparian zone modification and instream habitat quality). The a priori selected reference sites were subjected to validation using multivariate methods such as analysis of similarities (ANOSIM), similarity percentages (SIMPER) and non-parametric multidimensional scaling (MDS) based on the macroinvertebrate fauna by applying a SASS5 threshold considered to be an indicator of undisturbed sites in South African rivers. We identified differences in the macroinvertebrate assemblages of the reference conditions for each river group based on their ecoregions, geomorphology and seasonal variations. Ecoregions and river geomorphology were better in the grouping of sites with similar reference conditions than the seasons. Our findings indicated that all of the selected sites could be considered as valid reference sites; however, caution should be taken in applying this method to lowland rivers because of their noticeable seasonal variability and habitat instability which tend to alter their reference states. We recommend that a type-specific reference condition be developed for lowland rivers. Also, statistical validation of reference conditions should be a continuous process in river biomonitoring.

Damming effect on habitat quality of riparian corridor

• This work delimits multi-criteria based riparian corridor. • The riparian habitat quality was evaluated for pre and post HA phases. • The riparian zone was decreased by 12.29% in post HA phase. • The very poor riparian quality area has increased over time. • The riparian quality models were validated using ROC, wilcoxon signed rank test. Riparian corridor, a vital ecotonian ecosystem is under stress due to flow reduction and inconsistency of flow in Lower Tangon river basin across the neo tectonically active Barind tract of India and Bangladesh. But it is ill defined and its habitat quality is rarely assessed insipite of its immense socio-ecological importance. The present work intends to delineate the riparian corridor and quality assessment of the riparian habitat in reference to the hydrological alteration (HA) triggered by anthropogenic activities, mainly damming in 1989. The present work applied multi-parametric (altitude, topographic roughness, water body, forest patches) approach for delineating the riparian corridor instead of existing uni-criterion approaches for the same. Quality assessment of the habitat is done using nine surface, ecological, hydrological and anthropogenic parameters in the Arc Gis platform employing advance machine learning algorithms like Fuzzy logic (FL), Artificial Neural Network (ANN), Random Forest (RF), Random subspace, Dagging and Support vector machine (SVM). Total 20.63 km 2 and 18.36 km 2 areas respectively in pre and post-HA periods alongside the main river are identified as the riparian corridor. HA has reduced the area under the riparian corridor by 12.29% in post-HA state. Simultaneously, the quality of the riparian habitat is also deteriorated in the post-HA period. In pre-HA state, 49.05% area was under good to very good riparian habitat but it is reduced to 11.86% in post-HA state. Regularization of the flood, release of ecological flow to the downstream, renovation of tie channels between flood plain and river, restriction in agricultural invasion towards riparian forest and wetland are some of the essential steps for minimizing qualitative deterioration of riparian habitat and amelioration of the ecosystem concerned.

Changes in streamside riparian forest canopy and leaf litter nutrient flux to soils during an emerald ash borer infestation in an agricultural landscape

The invasive forest insect pest, emerald ash borer (EAB), is causing rapid, widespread ash tree mortality across eastern North America. Riparian (streamside) forests in agricultural landscapes often represent residual patches of high quality forest habitat that, owing to their strong land/water ecological linkages, can be critical for maintaining stream water quality and aquatic and terrestrial biodiversity. When riparian forests contain high numbers of ash trees, EAB can pose a risk of disrupting some of those land/water linkages thereby reducing riparian and aquatic habitat quality. We tracked ash tree mortality, streamside forest canopy cover, leaf litter deposition rates, and nutrient flux to soils in 18 riparian forest plots with an average of 24% ash by stem density over a 5 year period from early to late stages of an EAB invasion (2010–2015). Ash tree mortality increased from an average of 10–98% over 5 years in most plots, but when blue ash were dominant, final ash mortality was about 34%. Despite the nearly complete mortality of ash trees in almost all plots by 2015, the average canopy openness measured at 1.5 m above ground only increased to about 9%, which was significantly higher than the 2010 average of 6% open. Final canopy openness was significantly but weakly (r2 = 0.24) associated with the proportion of ash in riparian plots, indicating highly patchy openness resulting from ash mortality. Ash leaf litter deposition to streamside traps declined by 84% and elm declined by 20%, whereas leaf deposition from the other four most common contributors to riparian leaf litter increased by up to 37% over the same period. The large reductions in ash litter deposition were sufficient to reduce macro-nutrient flux to the streamside forest floor and therefore likely to streams. Amounts of N, C, P, K, and Ca delivered to the streamside soils via leaf litter fall were all consistently, some of them significantly, lower by 2014 than in the baseline year of 2010. Although total leaf litter mass returned to near pre-infestation levels by 2014, the altered composition of leaf litter caused a persistent reduction in nutrient flux to riparian soils. We also measured stem density of regenerating ash saplings ( 0.5 m height) at the end of the study period and found them to be abundant with an average of 2084 stems/ha. Our results provide an empirical demonstration of EAB-induced disruptions to ecological linkages and processes in riparian forests, at least over the short term.

Systems modeling to improve river, riparian, and wetland habitat quality and area

Systems models to improve ecosystems often identify flows to meet minimum instream flow requirements or minimize deviations from a predefined flow regime. Here, we present a new systems optimization model that determines when, where, and how much to allocate scarce water, financial resources, and revegetation efforts to improve aquatic, floodplain, and wetland habitat areas and quality. This optimization is subject to constraints on water mass balance, vegetation growth, infrastructure capacities, and meeting existing agricultural and urban water demands. We followed a participatory approach to apply and validate our model in the Lower Bear River watershed, UT. Results show that increasing winter reservoir releases, minimizing spring spills, and planting native floodplain vegetation early in the growing season can increase suitable habitat area beyond managing water alone. Additional flow on the Little Bear River between August and December will most increase habitat area and quality compared to other locations.

Relationship between agricultural pesticides and the diet of riparian spiders in the field

BackgroundExamining the effects of pesticides is difficult in regions such as Western Europe because of the relatively ubiquitous use of agrochemicals and the lack of unaffected areas. To study a wide gradient of agrochemical stress, we conducted a study in Central Romania, where traditional agriculture, which is assumed to use less agrochemicals, exists adjacent to intensive agriculture. We investigated potential effects of land use related stressors including pesticides on aquatic–terrestrial predator–prey relationships using stable isotope analysis. Therefore, we sampled spiders, as well as their aquatic and terrestrial prey along streams with a pesticide pollution gradient and determined spider and prey stable carbon and nitrogen signals.ResultsAquatic prey contributed 40.8–55.4% to the diet of the orb web weaving spider Tetragnatha sp. and 34.0–53.0% to the diet of the ground-hunting Pardosa sp. The biomass of potential aquatic prey increased along a gradient of increasing riparian habitat conditions and water quality and decreasing agriculture (e.g. arable land) in the catchment. The proportion of aquatic prey in the orb web weavers diet responded positively to the biomass of potential aquatic prey and negatively to this gradient. Increasing potential prey biomass resulted in an increasing proportion of aquatic prey for the orb web weaver. The proportion of aquatic prey in the ground hunters diet increased with in-stream pesticide toxicity and along a gradient of increasing pastoralism in the catchment as well as increasing riparian habitat and water quality.ConclusionThe diet of two riparian predators responded to complex gradients of catchment land use, stream and riparian habitat quality as well as to in-stream pesticide toxicity. The responses to the different environmental variables can be attributed to direct (e.g. change in spider community) and indirect (e.g. changes in aquatic prey and terrestrial prey) effects. Future manipulative field studies or experiments on aquatic–terrestrial food webs are required to examine the causality of our findings and should also consider the quality of prey organisms to foster mechanistic understanding of cross-ecosystem effects.

Riparian conservation management needs habitat quality mapping

Riparian habitat quality has a significant influence on the water quality of rivers, primary resources for urban and agricultural use. River water quality deteriorates where normal ecological functioning is dis- rupted by harmful impacts from nearby land-use types. Important rivers are typically managed and protected by government-led conservation programs. These programs often lack a key tool for efficient conservation management, habitat quality mapping. The Berg River, an important water source in South Africa, was used as a case-study to assess how habitat quality mapping could broaden the current scope of river conservation programs. The river faces threats from nearby urban settlements, industrial areas, mining, encroachment, and agricultural practices. The aim of this study was to develop habitat quality and habitat degradation maps for a section of the Berg River to assess the value that mapping holds for conservation managers and spatial planners. InVEST modelling software and ArcGIS was used to produce these habitat quality maps based on land-use/land-cover and threat impact data. The resulting maps showed several specific locations of heavily threatened and degraded riparian habitat that had not specifically been included in current government con- servation management or spatial planning. Habitat quality mapping is an important tool that conservation managers and spatial planners can use to successfully address habitat degradation and protection while fac- ing resource limitations, such as lack of funding. Oversight of degraded riparian habitats will lead to further decreases in river water quality, adversely affecting human welfare and local economies.

Cercopithecine and Colobine Abundance Across Protected and Unprotected Land in the Greater Mahale Ecosystem, Western Tanzania

Most primates live in unprotected land where abundances and threats may differ from those in protected areas. We therefore need to establish population densities in both unprotected and protected areas to effectively inform conservation planning. The Greater Mahale Ecosystem in western Tanzania is a region of mixed protected status with seven cercopithecine and colobine species: blue (Cercopithecus mitis doggetti), red-tailed (C. ascanius schmidi), and vervet (Chlorocebus pygerythrus) monkeys; ashy red colobus (Piliocolobus tephrosceles); black-and-white colobus (Colobus angolensis); and olive (Papio anubis) and yellow (P. cynocephalus) baboons. These species may be threatened by increasing human activity; however, except for ashy red colobus, no data on local abundances are available. We walked over 350 km of line transects in legally protected (Village Forest Reserves) and unprotected general land between August 2011 and October 2012 to estimate densities of primates and human activity. Primate densities were consistently low across the Greater Mahale Ecosystem. Blue and red-tailed monkey and ashy red colobus densities were especially low compared to populations in predominantly forested landscapes. Primate and human activity densities did not differ significantly inside and outside of reserves. Low primate densities could be natural responses to the lower proportions and quality of riparian forest habitat in the region. High levels of human activity and the absence of significantly higher primate densities in reserves suggest unprotected land could provide important refuges for primates in the Greater Mahale Ecosystem. This result further reinforces a broad need to include unprotected areas in primate conservation strategies.

Development of macroinvertebrate-based multimetric index and establishment of biocriteria for river health assessment in Malaysia

Abstract Economic and industrial growth in Malaysia has led to various environmental problems, which in turn affected the quality of human life and nature. At present, the management plans, particularly for river rehabilitation, are less effective in addressing issues related to Malaysian rivers. To date, most of the efforts undertaken have focused on evaluating the physicochemical properties of water, whereas biological evaluation determining the health of a river ecosystem is less attended to. Therefore, this study has aimed to develop a multimetric index and biocriteria applicable to the biological assessment of Malaysian streams. Four rivers in the state of Johor have been selected as the sources, each representing different gradients of land use. The reference and impaired sites both have been determined based on various physicochemical, instream features and riparian habitat quality criteria. The resulting candidate metrics have then been evaluated in terms of redundancy, sensitivity and responsiveness to environmental changes, using the stepwise procedures. Integration of six potential metrics across three categories (i.e. taxonomic richness, taxonomic composition, and tolerance and intolerance index) has consequently produced a four-level discriminatory biocriteria for river health assessment: 93% (non-impaired). The re-scored result has revealed that the water quality of Sg Ayer Hitam Besar to be non-impaired, with excellent water quality. Meanwhile, Sg Berasau and Sg Mengkibol have slightly impaired water quality, whereas Sg Melana is moderately impaired with fair to poor water quality. Thus, this multimetric index has strongly differentiated the reference and impaired conditions accordingly, which substantiated the suitability of the discriminatory criteria for Johor stream assessment. Hence, the establishment of macroinvertebrate-based index of biotic integrity (MIBI) and biological criteria may provide indispensable information in managing river ecosystem more effectively.

Soil bioengineering techniques enhance riparian habitat quality and multi-taxonomic diversity in the foothills of the Alps and Jura Mountains

Riparian zones have disproportional ecological importance relative to their size. For decades, the functionality of riparian zones has been altered, with detrimental consequences on biodiversity. Recently, riparian zone restoration has become a major issue. When channel mobility cannot be restored and when erosion control is of primary concern, soil bioengineering techniques are often viewed as a compromise solution. We studied 37 riverbanks, from civil engineering to soil bioengineering, plus natural willow stands, in the foothills of the Alps and Jura Mountains. Using a principal component analysis, we first studied whether terrestrial and aquatic habitat variables varied among riverbank stabilization structures and bank stabilization age and built a synthetic index of riparian habitat quality reflecting the multivariate similarity of riverbank sites. Then, using a modelling approach, we tested whether multi-taxonomic diversity responded to changes in habitat quality and to broad-scale environmental variables (i.e., climate, hydrology and land cover). Soil bioengineering techniques, especially willow fascines and to lower extend vegetated crib wall, enhanced riparian habitat quality by allowing for a greater richness and density of pioneer tree species but also for a larger cover of high quality aquatic micro-habitats. This increase in riparian habitat quality induced an increase in both terrestrial and aquatic species diversity, highlighting the added-value of soil bioengineering techniques to restore riparian biodiversity. This may confirm that stabilization structures made of willow fascines are better suited than stabilization structures made of artificial substrata to support riparian species. Also, beyond the positive effect of soil bioengineering techniques for riparian biodiversity, we found that climatic, hydrological and land cover variables strongly influenced diversity patterns. Thus, multi-taxonomic diversity decreased along larger rivers and in landscapes dominated by urban areas. This may indicate that the full added value of soil bioengineering techniques for biodiversity will only become apparent if more attention is paid to mitigating the negative impact of human activities in the vicinity of riparian zones and if larger scale environmental parameters are taken into account as early as possible in restoration project. Therefore, we strongly recommend that riverbank restoration projects, based on the active introduction of native pioneer tree species, should be planned at the catchment scale.

Louisiana Waterthrush (Parkesia motacilla) survival and site fidelity in an area undergoing shale gas development

We quantified Louisiana Waterthrush (Parkesia motacilla) site fidelity and apparent survival across a 6 year period in an area undergoing shale gas development.Waterthrush initially exhibited high site fidelity that declined over time. At the same time, the number of unpaired males defending territories increased as did natal fidelity. We identified site fidelity factors that influenced if adult males and females returned. More males returned either due to or regardless of amount of shale gas disturbance and lower riparian habitat quality. Females were less likely to return with increased number of breeding attempts. Females in shale gas disturbed areas had a higher number of breeding attempts and lower individual productivity. We saw a general nonsignificant trend in declining apparent survival over time. Overall apparent survival estimates for adult males (0.56) and females (0.44) were similar to those reported for other populations. Apparent survival candidate models suggested weak, positive relationships of increased survival with shale gas territory disturbance, disturbance with year, and year for adult males, and a positive relationship of increased survival with hydraulic fracturing runoff for adult females although regression coefficients overlapped zero for all model-supported covariates implying no statistical significance. Since waterthrush can maintain pair bonds from the previous year and females must pick a nest site within the defended male's territory, there are potential conflicts between factors that influence adult survival and site fidelity that may affect long-term population persistence. Our study adds to previous evidence that shale gas disturbed areas may serve as sink habitats.

Importance of scale, land‐use, and stream network properties for riparian plant communities along an urban gradient

Abstract Riparian forests along urban streams are affected by flashy hydrological regimes and adjacent upland land‐use, and their downstream dynamics are altered by forest fragmentation and by frequent river network truncation. This can lead to lower riparian habitat quality, decreased dispersal along the river network and increased recruitment of novel plant communities including non‐native species. Compared to forested landscapes, our understanding of riparian plant community diversity and composition along urban river networks is poor. We investigated riparian plant communities and riparian habitat variables along seven river networks situated along an urban gradient in the Greater Toronto Area, Canada. Six land‐use metrics classifying the intensity of urbanisation on three spatial scales (sub‐catchment, upstream riparian buffer, site buffer) were tested to explain the variation in riparian plant communities along the river networks and to describe the differences in riparian habitat. Riparian plant diversity peaked at sites which had between 40% and 70% of built‐up land cover within sub‐catchments; however, these communities contained a large number of non‐native species compared to the forested streams. While total species richness and native species richness were more related to river network factors (catchment area), non‐native richness was also affected by land‐use within a site. Community composition was more related to local land‐use than catchment area. Geographical distance between sites (both overland and hydrological) was increasingly more important for community heterogeneity along the urbanisation gradient. Riparian habitat worsened along the urbanisation gradient, with higher disturbance and soil pH and lower soil organic content and bryophyte cover in the more urban catchments. Riparian habitat variables were also related to the position along the river networks. Our results provide important insights into how riparian plant communities and riparian habitat differ along a gradient of urbanisation. Compared to previous studies we investigated the patterns in riparian vegetation in the context of river networks, including a variety of land‐use metrics, and analysed data across different spatial scales. This revealed important trends in plant diversity, demonstrated that urban land‐use increases the occurrence of non‐native species, and showed that the land‐use at the local scale is a stronger determinant of plant assemblages compared to land‐use at broader scales. These novel findings can be applied to land management in order to mitigate the effects of urbanisation on riparian ecosystems and the functions they provide for adjacent streams and rivers.

Demographic response of Louisiana Waterthrush, a stream obligate songbird of conservation concern, to shale gas development

ABSTRACT Shale gas development continues to outpace the implementation of best management practices for wildlife affected by development. We examined demographic responses of the Louisiana Waterthrush (Parkesia motacilla) to shale gas development during 2009–2011 and 2013–2015 in a predominantly forested landscape in West Virginia, USA. Forest cover across the study area decreased from 95% in 2008 to 91% in 2015, while the area affected by shale gas development increased from 0.4% to 3.9%. We quantified nest survival and productivity, a source–sink threshold, riparian habitat quality, territory density, and territory length by monitoring 58.1 km of forested headwater streams (n = 14 streams). Across years, we saw annual variability in nest survival, with a general declining trend over time. Of 11 a priori models tested to explain nest survival (n = 280 nests), 4 models that included temporal, habitat, and shale gas covariates were supported, and 2 of these models accounted for most of the variation in dai...

A spatially explicit patch model of habitat quality, integrating spatio-structural indicators

Habitat quality – referring to the structure of a habitat – is crucial for the habitat functions and biodiversity-related ecosystem services. Its effective assessment and monitoring is important to meet not only scientific interest, but also practical conservation regulations. We herein present the approach of using a composite indicator of riparian forest quality, both quantitatively (habitat quality index HQI [0|1]) and categorically (quality types QT1…4), integrating a set of spatio-structural indicators derived from earth observation data. We apply the geon concept to aggregate multiple sets of statistically profound and conceptually meaningful indicators to the well-established patch concept. The main difference is that instead of using a priori units (e.g. existing patch delineations), new patches (geons) are derived that directly represent the phenomenon of habitat quality. Patch boundaries correspond to the gradients imposed by the multivariate behavior of the underlying indicators. The approach provides a truly spatially explicit assessment, while at the same time retaining the potential for decomposability on the level of individual indicators. The example of a riparian forest is chosen, as riparian zones are complex ecosystems with a high biodiversity that are highly threatened. In our case, riparian forest habitat quality was assessed using four indicators: (I) tree species composition, (II) horizontal forest structure, (III) vertical forest structure, and (IV) water regime. The distribution of habitat quality (HQI) highlights hot- and cold-spots, where conservation measures may be needed. Cluster analysis reveals four types of patches that are characterized by a specific behavior of the aggregated indicators (QT1=fair composition, QT2=(old growth) forest plantations, QT3=characteristic tree species, QT4=forest gaps). This categorization enables the prevailing or lacking aspects of quality to be determined based on the decomposability of the index. In addition, the resulting patches were evaluated using landscape metrics. The findings achieved on a statistically significant level show that patches with high HQI scores are better connected and form large patches with a characteristic tree species composition. In contrast, areas with low HQI values are characterized by a non-favorable tree species composition and the existence of clear-cut areas or access roads. A comparison with an assessment using a traditional composite indicator approach reveals the sensitivity of the different sets of indicators and assessment methods. The presented habitat quality index can be considered as suitable for the assessment and monitoring of riparian forest quality, supporting spatially explicit conservation measures and the evaluation of applied measures.