Target Habitat Research Articles

A genetic assessment of natural barriers for isolating a proposed Greenback Cutthroat Trout reintroduction area

AbstractObjectiveNative inland trout conservation efforts rely on physical barriers to exclude nonnative salmonids from target habitats. We used genetic techniques to evaluate a series of natural waterfalls for their potential to serve as barriers to prevent nonnative salmonids from entering a proposed reintroduction area for federally threatened Greenback Cutthroat Trout Oncorhynchus virginalis stomias.MethodsGenetic samples were collected from nonnative Brook Trout Salvelinus fontinalis at 11 sampling reaches above and below natural waterfalls (height: ~1–3 m under base flow conditions) along a 33‐km segment of Colorado's upper Cache la Poudre River near the outflow of the proposed reintroduction area. To evaluate whether upstream movement of Brook Trout is restricted by any of these waterfalls, we characterized longitudinal trends in genetic diversity along the river corridor and examined patterns of genetic differentiation and population structure in relation to waterfall locations using a panel of microsatellites.ResultWe found no evidence that the waterfalls served as complete movement barriers for nonnative Brook Trout based on genetic clustering analyses, estimates of population differentiation, and longitudinal genetic patterns. Our multilocus assessment did not identify alleles restricted to downstream reaches, and the river segment was genetically homogenized.ConclusionOur evaluation suggests that the existing waterfalls do not fully prevent upstream movement by nonnative Brook Trout, and thus barrier modification would be needed to establish an isolated Greenback Cutthroat Trout population in the proposed wilderness area.

Square-grid sampling to address the vegetation patterns of declined Mediterranean forest ecosystems

Palo Laziale Wood is a relatively small biotope (129 ha) situated along the coast of the Metropolitan Area of Rome, Lazio region, Italy. Despite being one of the region's remaining patches of an ancient oak floodplain broad-leaved forest, it conserves numerous priority habitats and species of high conservation interest. The vegetation consists mainly of Turkey oak stands with small temporary ponds and flooded meadows. The forest underwent a dieback in 2003, triggered by a significantly hot and dry summer. In 2018, an ecological restoration project (LIFE PRIMED LIFE17 NAT/GR/000511) was initiated to restore Palo Laziale’s ecosystems. This paper presents the methodological approach employed to assess the vegetation ecology of a degraded forest ecosystem. Such an investigation was a key component of the Adaptative Restoration Plan of the Project. It provided the baseline necessary for designing and calibrating the planned direct conservation actions on the target habitat types (91M0: Pannonian-Balkanic turkey oak-sessile oak forests, 3170*: Mediterranean temporary ponds, 5230*: Arborescent matorral with Laurus nobilis, etc.) and establishing reference values to enable long-term monitoring. Plant taxa comparison from 1 ha square-grid sampling and multivariate analyses were carried out to group species and identify environmental and Ellenberg-based drivers. Six ecologically distinct units were found, eventually confirming the distinctive ecological heterogeneity of Mediterranean ecosystems. Amongst these, the hygrophilous vegetation has resulted to be the one mainly affected by the dieback outbreak. Due to the high heterogeneity, introduced by the massive tree mortality, the method of regular 1 ha squares turned out to be a reliable alternative to random vegetation sampling plots (e.g., phytosociological relevés) to disentangle ecological patterns of fragmented and disturbed habitats.

Easement of forests and forest land for the growing of perennial crops - the analysis of (non)functionality regarding the ecological network and ecosystem functions

By the Government's decisions from the period 2004 to 2013, a significant amount of state forests and forest land was eased for the growing of perennial crops (vineyards and olive yards) on a total surface of 24,310.24 ha throughout the state. Although greatly opposed by forestry professionals, since a vast amount of private agricultural land in the state is not utilized due to unresolved proprietary issues, these surfaces have become agricultural land by coming into force from the Forest Act of 2014. In case these dedicated surfaces are not put into function, the amount of non-utilized agricultural land is increasing and so is the danger from forest fires, and loss of biological and landscape diversity. On the other hand, if all these surfaces were utilized, a significant adverse impact on the ecological network would occur because on many ecological network sites more than 1% of the dedicated area consists of target habitat types (mostly maquis). The purpose of this paper is, to use GIS tools and analysis of the so-far signed easement contracts, to determine what amount of dedicated surfaces were utilized and point out the failure and environmental dangers that may arise from these decisions which can still be revoked, and the affected area can be brought back into the forest area of the Republic of Croatia, i. e. sustainable forest management can still be reinstated and forest functions restored.

Marginal value analysis reveals shifting importance of migration habitat for waterfowl under a changing climate.

Migratory waterfowl are an important resource for consumptive and non-consumptive users alike and provide tremendous economic value in North America. These birds rely on a complex matrix of public and private land for forage and roosting during migration and wintering periods, and substantial conservation effort focuses on increasing the amount and quality of target habitat. Yet, the value of habitat is a function not only of a site's resources but also of its geographic position and weather. To quantify this value, we used a continental-scale energetics-based model of daily dabbling duck movement to assess the marginal value of lands across the contiguous United States during the non-breeding period (September to May). We examined effects of eliminating each habitat node (32 × 32 km) in both a particularly cold and a particularly warm winter, asking which nodes had the largest effect on survival. The marginal value of habitat nodes for migrating dabbling ducks was a function of forage and roosting habitat but, more importantly, of geography (especially latitude and region). Irrespective of weather, nodes in the Southeast, central East Coast, and California made the largest positive contributions to survival. Conversely, nodes in the Midwest, Northeast, Florida, and the Pacific Northwest had consistent negative effects. Effects (positive and negative) of more northerly nodes occurred in late fall or early spring when climate was often severe and was most variable. Importance and effects of many nodes varied considerably between a cold and a warm winter. Much of the Midwest and central Great Plains benefited duck survival in a warm winter, and projected future warming may improve the value of lands in these regions, including many National Wildlife Refuges, for migrating dabbling ducks. Our results highlight the geographic variability in habitat value, as well as shifts that may occur in these values due to climate change.

Effectiveness of UK Legislation and Management in Producing Nature Conservation Outcomes

National Nature Reserves (NNRs) are a form of nature conservation management using protected areas to improve specific site features of wider biodiversity. This study focuses on the Purbeck Heath NNR management aims to restore the natural habitat and increase overall biodiversity through landscape-scale management. This study investigated whether landscape-scale management used within the protected areas will benefit overall biodiversity and fulfil legislation. Sites observations were used to assess public compliance in accordance with the legislation and management measures of the specific site, whilst personal communications were carried out to gain representations of what key ecological measures are currently used on site. Bayesian Belief Networks were used to evaluate how different designated features within NNRs will continue to perform under current management methods. Results showed that protected designated features within the reserve would improve under the landscape-scale management of the Purbeck Heath NNR with ecosystem services, biodiversity, protected target species, and protected target habitat likely to increase despite climate change likely to increase. Discussions showed that the main conservation outcome is to increase landscape connectivity, climate resilience and overall biodiversity by placing nature first. Overall, the Purbeck Heath NNR and other super NNRs have the potential to fulfil the legislation aims set out under the various designations of Special Protected Areas, Special Areas of Conservation, Sites of Special Scientific Interest, and Ramsar sites.

Physical and Chemical Properties of Limestone Quarry Technosols Used in the Restoration of Mediterranean Habitats

The lack of topsoil is frequently a limiting factor in limestone quarry restoration. This implies that new technosols for maintaining target habitats must be created using mining wastes as the main components. We designed three different technosols using different combinations of mineral materials (mining wastes, excavated soils and topsoil), organic amendment types (compost and digestate) and doses for the restoration of target habitats. Moreover, we monitored the main physicochemical indicators of the quality of the technosols. We observed not only an increase in soil organic carbon and plant nutrients related to the application of any type of organic amendment, but that the digestate mostly increased the soil resistance to erosion by improving soil aggregation even before the emergence of vegetation. Soil-water-retention capacity only improved in technosols built with organic amendments and topsoil. The combination of mining wastes, organic amendments and a superficial horizon of topsoil resulted in the most optimal technosol for the restoration of limestone quarries in the Mediterranean climate.

Identification of wetland conservation and restoration priorities in regions of oil extraction in the Yellow River Delta using circuit theory modelling

Oil exploration fragments coastal wetland habitats, which often leads to biodiversity loss and ecosystem degradation. Assessing the negative effects of oil infrastructures at the landscape scale is critical for practical coastal wetland management and the planning of protected areas (PAs). However, information gaps involving wetland connectivity and oil exploration exist in current conservation, which limit the efficiency of PAs.Here, we used a GIS-based circuit theory model (Circuitscape) and high-resolution remote sensing data to simulate the movement patterns of random species and to elucidate the effects of oil wells on their connective elements in four types of wetlands (mudflat, saline marsh, shrub wetland and forest wetland) in the Yellow River Delta (YRD), China. The effectiveness of the Yellow River Delta Nature Reserve (YRDNR) in protecting wetland connectivity was evaluated. A planning framework to optimize wetland conservation and restoration by Linkage Mapper was then provided to improve the landscape connectivity of oil well-disturbed wetlands in this region.The results showed that oil wells significantly decreased wetland connectivity and altered their connective elements in the four wetlands of the YRD. Both the resistance of wetland species movement and the heterogeneity of species dispersal have increased. The length of potential corridors and areas possessing barriers to movement have increased by 126 km (20%) and 51 km2 (120%), respectively. Areas with pinch points that promote species movements, however, decreased by 1178 km2 (60%). The YRDNR protected less than 50% of the key corridors and ecological nodes, considering the impacts of oil wells. Mudflat is seriously affected by oil wells in the YRDNR. Consequently, new alternative corridors produced by oil wells and pinch areas at high risk of impacts by oil wells have the highest protection priorities, whereas those permeable barrier areas, such as croplands and paddy fields, have the highest restoration priorities. The results also illustrated the importance of rivers and water bodies as potential shelters for wetland species.Our research suggests that circuit theory model is an effective planning tool to quantify the negative impacts of oil activities and to identify the protection or restoration priorities of ecological hot spots which are unable to be detected by traditional PAs method. This work provides guides for improving landscape connectivity and specifying target habitats for coastal conservation management.

Combined empirical techniques reveal key role for variation in plasticity in a novel environment.

This article is a Commentary on Walter et al. (2023), 239: 374–387.

Ecosystem services valuation using InVEST modeling: Case from southern Iranian mangrove forests

As one of the most fertile ecosystems on earth, mangrove forests provide many goods and services for humanity. Mangroves are located in the south of Iran on the coasts of Sistan and Baluchistan, Hormozgan and Bushehr provinces, which include two species of Harra (Avicennia marina) and Chandal (Rhizophora mucronata) The purpose of this study was to describe the condition of mangrove forests using the integrated valuation of ecosystem services and tradeoffs (InVEST) between 2010 and 2021 from the southern coasts of Iran. The INVEST model uses land use and land cover maps to estimate habitat quality. With the opinions of local experts, sources of threats, maximum impact distance, state of degradation, and sensitivity to threats were also estimated for each type of land use cover. Urban and rural areas’ development, roads network, piers, oil and non-oil industries, agriculture, and aquaculture activities, were identified as sources that threaten mangroves’ long-term viability. The output maps of the INVEST habitat quality model included degradability and habitat quality maps, which were classified into four categories: poor, low, medium, and high, to better understand quality changes. The results demonstrated that mangrove habitat quality has decreased considerably despite the increase in their area. The area of the target habitats has been increased by 586.45 ha while two first quality categories, including poor and low classes, increased. Based on a habitat quality assessment in 2010, two classes of poor, low habitat quality, were estimated to be around 0.72, and 8.42 ha, which changed to 3.04 ha, and 9.72 ha respectively in 2021. The output maps obtained in this study can help local managers and decision-makers to have an image of what happened to the quality of the target ecosystems and may help them to adopt more effective management strategies for the conservation of these ecosystems.

Ecological Restoration of Pinus Pinaster Woodlands, After Degradation with Focusing on Rehabilitation of Target Habitats

Ecological restoration plays a vital role in preserving and rehabilitating degraded habitats, especially those populated by endemic species. This abstract focuses on the restoration efforts of Pinus pinaster and other endemic species found in woodlands that have suffered degradation. The primary aim of this restoration project is to rehabilitate target habitats and promote the recovery of these native species in Portugal. The identification of key factors that have contributed to the degradation is crucial in developing effective restoration plans. Additionally, understanding the ecological requirements and preferences of the target species is essential to ensure successful rehabilitation. Ecological restoration of Pinus pinaster woodlands/forests, after degradation such as posed by recurrent fires and invasive species, Focusing on rehabilitation of target habitats, such as water lines and other key elements of the landscape (we have important areas of Pinus pinaster in the secondary coastal dunes) Using native species of the selected sites, that may be present in the vegetation or in the soil seed bank- Testing and evaluating the best propagation techniques for each species, vegetative cuttings, seeds germination, in situ or ex situ propagation, Evaluating the added value of the restoration actions in terms of 1) increasing or protecting ecosystem services, 2) increasing or protecting rare or potentially endangered plant species, etc. In conclusion, the ecological restoration of Pinus pinaster and other endemic species in degraded woodlands requires a multidimensional approach that addresses key factors contributing to habitat degradation. By focusing on the rehabilitation of target habitats, these restoration efforts contribute to the conservation and preservation of these important ecosystems, ultimately benefiting both the endemic species and the surrounding communities.

Interaction of Microplastic Presence and Oxidative Stress in Freshwater Fish: A Regional Scale Research, East Anatolia of Türkiye (Erzurum & Erzincan & Bingöl)

The presence of microplastic (MP) in different fish species taken from stations in Erzurum, Erzincan and Bingöl was examined. The obtained data were classified and shared with the scientific world as the first record made in this region. In the obtained results, the most dominant color was black (39–58%) and the most prevalent forms were fragment and fiber. The sizes (0–50, 50–100 µm) of microplastics differed according to the region and species. When the number of MPs in the gastrointestinal systems of different fish species in the Bingöl, Erzurum and Erzincan provinces was evaluated, the most microplastics were found in Squalius squalus (20.7%) and Blicca bjoerkna (18.2%) in Bingöl province from among six different species. In Erzincan province, four fish species were sampled, and the rates were (29.7%) in Capoeta umbla and (26.6%) in Blicca bjoerkna. The highest abundance in Erzurum province was determined in Cyprinus carpio (53.0%). In the analyses performed on liver tissues, the highest ROS, which is the indicator of oxidative damage, was listed as Bingöl > Erzincan > Erzurum, while MDA levels were recorded as Bingöl > Erzurum > Erzincan, from high to low. When the differences between species were examined, the highest SOD and CAT activity was determined in the Mugil cephalus species. Considering the total MP numbers in fish samples, 47 MP was determined in this species. On the other hand, in the Squalius squalus species, where the highest total MP was determined, SOD and CAT activities were found to be low in Bingöl province. Therewithal, the high levels of ROS and MDA in this species can be said to induce oxidative stress due to the presence of microplastics on the one hand and to reduce antioxidant levels on the other hand. When the findings were evaluated, it was concluded that MPs in freshwater are a potential stressor, and freshwater environments may represent a critical target habitat for future MP removal and remediation strategies.

Ecosystem multifunctionality lowers as grasslands under restoration approach their target habitat type

Biodiversity is declining at a rapid pace and, with it, the ecosystem functions that support ecosystem services. To counter this, ecosystem restoration is necessary. While the relationship between biodiversity and ecosystem functioning has been studied in depth, the relationship between ecosystem restoration and ecosystem functioning is studied less. We performed an observational study in grasslands undergoing restoration management towardNardusgrassland. Eight ecosystem functions, representing flows of energy, matter or information between functional compartments, were measured across five successive restoration phases along the restoration gradient. The levels of functioning were then compared along the gradient for both the individual functions and a multifunctionality index. We hypothesized that plant richness increases when grasslands are more restored and this increase in biodiversity is paralleled by an increase in ecosystem functioning. In our study, the degraded grasslands, generally occurring on more nutrient‐rich soils, were dominated by competitive fast‐growing species, resulting in higher process rates and thus in higher, faster functioning. Likewise, more restored grasslands exhibited slower process rates and, thus, lower functioning. When studying ecosystem functioning, value judgments are easily made. Especially in a restoration context, high functioning does not necessarily equals well functioning, as this depends on the stakeholder perspective. We need to ask ourselves if a high functioning ecosystem is most desirable, especially in a restoration or conservation context. Policy frameworks will need to balance these goals.

Linking habitat interactions and biodiversity within seascapes

AbstractHabitat interactions play key roles in regulating biodiversity and ecosystem functions. This is particularly important in aquatic ecosystems, where the flow of water facilitates exchanges of energy and matter. Oyster reefs, a highly degraded habitat globally and a key focus for restoration efforts, can reduce water movement and facilitate the deposition of particles around them, affecting nutrient cycling in surrounding sediments. The effects of these reefs on sediment infauna taxonomic and functional biodiversity, however, remain unknown. We sampled sediments at increasing distances from reefs at three estuaries to evaluate the relationships between proximity to oyster reefs and composition and functionality of infaunal communities and explored the potential mechanisms behind those relationships. Sediments close to oyster reefs had consistently greater amounts of labile organic matter, which in turn was positively related to the number of taxa and total abundance of infauna. Also, the functional traits of infauna, such as bioturbation and feeding modes, were related to proximity to reefs, but they were variable between estuaries indicating the importance of background estuarine environmental conditions. These results suggest that habitat linkages between oyster reefs and sediments are important in regulating taxonomic biodiversity, while functional biodiversity seems to be driven by processes operating at larger scales. Given burgeoning restoration initiatives worldwide, particularly those of oyster reefs, incorporating seascape interactions can help inform recovery of biodiversity and functions beyond the target habitat at the seascape level, which is often overlooked.

The incidence of alien species on the taxonomic, phylogenetic, and functional diversity of lentic and lotic communities dominated byPhragmites australis(Cav.) Steud

This study aims to investigate, for the first time, the multiple diversity harbored in plant communities dominated byP. australis, discriminating between lentic and lotic habitats. We focused on the incidence of alien species on taxonomical, phylogenetic and functional diversity. Although it was hypothesized that ecological differences between habitats (lentic vs. lotic) could lead to plant adaptive trade-offs, results showed that theP. australisdominance affected overall plant diversity in the same way in both target habitats. Similarly, the two compared habitats hosted a similar alien species richness and relative abundance. Different results were observed based on whether the alien species richness or their relative abundance were considered regarding the incidence of alien species. Increasing alien species richness in lentic habitats resulted in increased taxonomic, phylogenetic and functional diversity. Instead, in lotic habitats, it promoted a decrease in taxonomic and functional diversity. In contrast, the increase in the relative abundance of alien species resulted in increased taxonomic, phylogenetic and functional diversity in both habitats. Choosing relative abundance vs richness of aliens in lotic stands can have a different impact in evaluating the effect of aliens on various components of diversity.

Herbivory and misidentification of target habitat constrain region-wide restoration success of spekboom (Portulacaria afra) in South African subtropical succulent thicket.

Restoration of degraded subtropical succulent thicket, via the planting of Portulacaria afra (spekboom) truncheons, is the focus of a public works programme funded by the South African government. The goals of the programme, which started in 2004, are to create jobs, sequester carbon, restore biodiversity, reduce erosion, improve soil water holding capacity and catalyse private sector investment for upscaling of restoration. Here we report on a region-wide experiment to identify factors that can improve project success. Measures of success were survivorship and annual aboveground biomass carbon sequestration (ABCsr) of spekboom truncheons some 33–57 months after planting—starting in March 2008—into 173 fenced plots (0.25 ha) located throughout the global extent of spekboom thicket vegetation. We also collected data for 18 explanatory variables under the control of managers, and an additional 39 variables reflecting soil physical and chemical characteristics and rainfall patterns post restoration, all beyond the influence of managers. Since the latter covariates were available for only 83 plots, we analysed the two data sets separately. We used a prediction rule ensemble to determine the most important predictors of restoration success. There was great variation in percentage survivorship (median = 24, range = 0–100%) and ABCsr (median = 0.009, range = 0–0.38 t C ha−1 yr−1). The model using management variables explained less variance (53%) in survivorship than the model incorporating additional soil and rainfall covariates (62%). ABCsr models were better fits (78 and 88% variance explained, respectively). All model configurations identified browse intensity as a highly influential predictor of restoration success. Predicted success was highest for plots located in target habitat; however, only 45% were thus located, suggesting the need for expert input and habitat modelling for improving target habitat identification. Frost exposure was another important predictor influencing all models but was likely a consequence of locating sites off target habitat. Sites planted on equatorward slopes during the warm season showed reduced carbon sequestration, possibly due to elevated soil moisture stress associated with high radiation loads. Physiographic factors associated with improved restoration success were location on sloping ground (reduced frost exposure), increasing longitude (more warm-season rainfall) and increasing latitude (less frost coastwards). Few trends were evident among post-restoration climatic factors beyond the control of managers. Higher rainfall during the year post restoration had a negative impact on carbon sequestration while higher rain during the early months post restoration had a positive effect on both carbon sequestration and survivorship. Soil factors showed little importance for the survivorship model, whereas silt content, % K and Mg CEC emerged as predictors of carbon sequestration. Our results have direct relevance for improving the success of landscape-scale restoration projects envisioned for the ca. 8,930 km2 of degraded spekboom thicket.

The response of plants, carabid beetles and birds to 30 years of native reforestation in the Scottish Highlands

Abstract Globally, there is increasing interest in tree planting, leading to many country‐level commitments to reforestation. In the UK, current commitments would achieve 17% forest cover by 2050, with the highest rates of forest expansion expected in Scotland. Forest expansion with native trees is expected to increase biodiversity, particularly woodland specialist species, and associated ecosystem services. Despite this, data on biodiversity changes over the early stages of reforestation are sparse, particularly for upland areas in Scotland where opportunities for forest expansion are greatest. We collected data on the response of plants, carabid beetles and birds to native reforestation and grazing exclusion, using sites reforested over the last 30 years in the Scottish Highlands. Biodiversity in ungrazed, reforested sites was compared to unforested controls and mature native forest, both grazed and ungrazed. Mean bird species richness in reforested plots (4.4 [95% CI: 3.2, 5.9]) was higher than in unforested plots (0.8 [0.5, 1.3]), but lower than in mature forest plots (7.0 [5.4, 8.3]). In contrast, there was no systematic difference in plant or carabid beetle species richness in reforested, unforested or mature forest plots, or between grazed and ungrazed plots for the species richness of any groups. Woodland specialist bird and plant species were found in the reforested plots, and richness of woodland specialist bird species was predicted to reach levels in mature forest c. 36 years after reforestation. Species assemblages differed across habitat categories. For birds and plants, species assemblages in reforested sites were intermediate to unforested and mature sites. For carabid beetles, the assemblages in mature and reforested sites were comparable and differed from unforested sites. Grazing did not strongly influence species assemblages. Policy implications. We show that woodland specialists colonise reforested sites and species assemblages transition towards those found in the target habitat within the first 30 years of reforestation with native species. Native forest should be prioritised in Scotland's future forest expansion targets, given that mature native forest is scarce and fragmented in the Scottish Highlands and that the ultimate gain from native forest expansion may accrue over long time‐scales.

A meta-analysis reveals edge effects within marine protected areas.

Marine protected areas (MPAs) play a leading role in conserving and restoring marine environments. MPAs can benefit both marine populations within their boundaries and external populations owing to a net export of organisms (spillover). However, little is known about variation in performance within MPAs. For example, edge effects may degrade populations within MPAs close to their boundaries. Here we synthesize empirical estimates of 72 taxa of fish and invertebrates to explore spatial patterns across the borders of 27 no-take MPAs. We show that there is a prominent and consistent edge effect that extends approximately 1 km within the MPA, in which population sizes on the border are 60% smaller than those in the core area. Our analysis of cross-boundary population trends suggests that, globally, the smallest 64% of no-take MPAs (those of less than 10 km2 in area) may hold only about half (45-56%) of the population size that is implied by their area. MPAs with buffer zones did not display edge effects, suggesting that extending no-take areas beyond the target habitats and managing fishing activities around MPA borders are critical for boosting MPA performance.

A biome-wide experiment to assess the effects of propagule size and treatment on the survival of Portulacaria afra (spekboom) truncheons planted to restore degraded subtropical thicket of South Africa.

Insights from biome-wide experiments can improve efficacy of landscape-scale ecological restoration projects. Such insights enable implementers to set temporal and geographical benchmarks and to identify key drivers of success during the often decades-long restoration trajectory. Here we report on a biome-wide experiment aimed at informing the ecological restoration of thousands of hectares of degraded subtropical thicket dominated by the succulent shrub, Portulacaria afra (spekboom). Restoration using spekboom truncheons has the potential to sequester, for a semi-arid region, large amounts of ecosystem carbon, while regenerating a host of associated ecosystem services. This study evaluates, after about three years post-propagation, the effects of spekboom truncheon size and treatment on survivorship in 40 fence-enclosed (0.25 ha) plots located in target habitat across the entire spekboom thicket biome. In each plot, locally harvested spekboom truncheons, comprising eight size/treatment combinations, were planted in replicated rows of between 24 and 49 individuals, depending on treatment. The experiment assessed the role of truncheon size, spacing, application of rooting hormone and watering at planting on survivorship percentage as an indicator of restoration success. All eight combinations recorded extreme minimum survivorship values of zero, while the range of extreme maximum values was 70-100%. Larger truncheons (>22.5 mm diameter) had almost double the survivorship (ca. 45%) than smaller truncheons (< 15 mm) (ca. 25%). Planting large, untreated truncheons at 1 m intervals-as opposed to 2 m intervals recommended in the current restoration protocol-resulted in no significant change in survivorship. The application of rooting hormone and water at planting had no significant effect on restoration success for both large and small truncheons. While our results do not provide an evidence base for changing the current spekboom planting protocol, we recommend research on the financial and economic costs and benefits of different propagation strategies in real-world contexts.

Modeling the Distribution of Habitat-Forming, Deep-Sea Sponges in the Barents Sea: The Value of Data

The use of species occurrence as a proxy for habitat type is widespread, probably because it allows the use of species distribution modeling (SDM) to cost-effectively map the distribution of e.g., vulnerable marine ecosystems. We have modeled the distribution of epibenthic megafaunal taxa typical of soft-bottom, Deep-Sea Sponge Aggregations (DSSAs), i.e., “indicators,” to discover where in the Barents Sea region this habitat is likely to occur. The following taxa were collectively modeled: Hexadella cf. dedritifera, Geodia spp., Steletta sp., Stryphnus sp. The data were extracted from MarVid, the video database for the Marine AREAl database for NOrwegian waters (MAREANO). We ask whether modeling density data may be more beneficial than presence/absence data, and whether using this list of indicator species is enough to locate the target habitat. We use conditional inference forests to make predictions of probability of presence of any of the target sponges, and total density of all target sponges, for an area covering a large portion of the Norwegian Barents Sea and well beyond the data’s spatial range. The density models explain &amp;lt;31% of the variance, and the probability models have high classificatory power (AUC &amp;gt; 0.88), depending on the variables/samples used to train the model. The predicted surfaces were then classified on the basis of a probability threshold (0.75) and a density threshold (13 n/100 m2) to obtain polygons of “core area” and “hotspots” respectively (zones). The DSSA core area comprises two main regions: the Egga shelf break/Tromsøflaket area, and the shelf break southwest of Røst bank in the Træna trench. Four hotspots are detected within this core area. Zones are evaluated in the light of whole-community data which have been summarized as taxon richness and density of all megafauna. Total megafaunal density was significantly higher inside the hotspots relative to the background. Richness was not different between zones. Hotspots appeared different to one another in their richness and species composition although no tests were possible. We make the case that the effectiveness of the indicator species approach for conservation planning rests on the availability of density data on the target species, and data on co-occurring species.

Generalized estimation of nutrient loading of waterbirds on inland aquatic ecosystems

Estimating the nutrient loading of aquatic bird is complicated because it is fundamentally dependent on several biological, environmental and methodological factors. The new Boros's generalized method is relatively easy to use based on the conventional bird counting and implemented excrement (faecal) analyses by integrated daily net rates data (g/day/ind.). According to the Boros's generalized method, the carbon (C), nitrogen (N) and phosphorus (P) loading of waterbirds on aquatic ecosystems can be estimated by determining the abundance of waterbird populations and the nutrient content (C, N, P) of their excrement. Weekly total loading of waterbirds = Σ species (A × E × RTF × D), where: A (ind./m2): the daily mean of abundance of waterbird species for each month, E (g/day/ind.): the daily net rate of C, N, P in the excrement of each species, RTF: the daily residency time factor (hours spent on soda pans/24 h) of each species in the target habitat, D (n days): the number of days of each month.•Waterbirds can cause extreme guanotrophication (max. 2500 mg P/m2/y) in waters.•The nutrient loading of waterbirds can be estimated by abundance of waterbirds.•Boros's method estimates the carbon, nitrogen and phosphorus loading of waterbirds.