Effects Of Habitat Restoration Research Articles

Microbial dynamics in Manaus river, Brazil

Rivers, which are vital ecosystems that support a variety of life forms and provide many ecosystem services, have been degraded by human activities, such as urbanization, pollution, and overexploitation. Habitat restoration projects have been implemented in different parts of the world to restore the ecological health and functioning of degraded rivers. The microbial community that forms biofilms on various substrates is one of the key components of river ecosystems. Organic matter is decomposed and carbon dioxide is produced by these biofilms, which affects the oxygen levels and nutrient cycles in the water. However, the effects of habitat restoration on the biofilm microbial community are not well understood. High-throughput DNA sequencing was used in this study to compare the bacterial composition of biofilms in three types of rivers: degraded urban rivers, urban rivers with restored habitats, and forested rivers that serve as reference conditions. The following questions were aimed to be answered: (i) How is the biofilm bacterial community composition affected by habitat restoration? (ii) How does bacterial diversity change in restored rivers compared to degraded and reference rivers? (iii) What are the environmental factors that influence the biofilm bacterial community composition? It was found that water quality was improved by habitat restoration by increasing the dissolved oxygen and reducing the organic pollutants in urban rivers. A decrease in bacterial diversity and a shift in the biofilm bacterial community structure towards that of the reference forested rivers were accompanied by this. This suggests that the biofilm microbial community can be altered by habitat restoration and its role in processing organic pollutants can be enhanced. However, it was also found that there was still a significant difference in the biofilm bacterial community between the restored and reference rivers, indicating that more time and effort are needed to achieve a similar ecological quality as the natural forested rivers.

Restoring Nature's Song: How Habitat Restoration Benefits Avifauna

Habitat restoration has proved to be a vital strategy in combating the widespread biodiversity loss caused by habitat degradation across the globe. The key roles played by avian species in critical ecosystem functions such as pollination, seed dispersal, and decomposition have made them an integral part of ecosystems, making them vital to the restoration process. Their detectability and cost-effective survey methods have positioned avifauna as focal species in ecological restoration research. This article delves into the effects of habitat restoration on avifaunal distribution, revealing a tapestry of positive outcomes. Restored habitats witness increased avian community diversity and evenness, heightened habitat heterogeneity, and greater densities of avian and migratory species. Avifauna's presence also facilitates breeding success, reduces nest parasitism, and fosters additional foraging and breeding grounds. Furthermore, habitat restoration has shown remarkable successes in reviving songbird populations in fragmented forests and rescuing endangered species like red-crowned cranes. In light of the transformative impact of avian restoration, understanding the effects of restoration on avifauna is pivotal in guiding management activities of restored sites. Implementing strategic management approaches such as predator control, maintaining habitat heterogeneity, controlling nest parasites, reintroducing natural disturbance regimes, and selecting appropriate plant species ensures a nurturing environment for avian survival. Additionally, promoting a heterogeneous environment in aquatic systems has proved crucial in enhancing bird diversity. Improving ongoing research and adaptive management practices further empowers restoration efforts, allowing us to compose a symphony of avian abundance, resilience, and harmonious coexistence with the natural world.

Effects of Habitat Restoration on Fish Communities in Urban Streams

Geomorphological alterations, hydrological disconnectivity and water pollution are among the dominant pressures affecting ecological integrity in urban streams. River restoration approaches often involve utilising in-stream structures to encourage flow heterogeneity and promote habitat diversity. However, few studies examine the success of such projects. In this study, fish density, biomass and community structure at paired restored and unrestored reaches across five tributaries of the River Thames were examined. Fish density varied among rivers and reaches but was generally higher at restored sites. Restored sites also exhibited higher overall fish biomass, attributed mainly to the presence of brown trout (Salmo trutta L.) at the River Wandle. Despite higher density and biomass values at restored sites, the community structure analysis did not identify strong links between either river or restoration status using either species-specific density or biomass. Our results highlight that although reach-scale restoration can lead to localised increases in species density and biomass, this may chiefly be due to aggregation owing to preferential habitats created through restoration activities at these sites. Over larger spatial scales, significant improvements to species richness and diversity are likely to be limited due to the poor water quality and disconnected nature of these urban streams. Whilst reach-scale restoration clearly has the potential to provide preferential habitats for fish species, future efforts should focus on improving connectivity for fish across the wider Thames basin network by removing barriers to passage, improving water quality, restoring watershed processes and creating well-connected, diverse habitats which can facilitate the survival of a wide array of fish species throughout their life cycle.

Effects of habitat restoration on peatland bird communities

Restoration of damaged ecosystems has become an important tool to slow down biodiversity loss and to maintain ecosystem services. Peatland bird populations have shown a substantial decline during the recent decades in Northern Europe as a consequence of peatland drainage. We studied whether restoration of peatlands drained for forestry affects bird communities. We conducted bird surveys at 11 peatlands in Western Finland, where each of the restored and their pristine counterparts were surveyed before restoration and yearly after restoration during 2010–2018. We used linear mixed effect models to analyze whether restoration affected the number of species and territories of peatland specialist and non‐specialist species and permutational multivariate analysis of variance to analyze the change in community composition. Drained parts of the peatlands had higher number of territories of non‐specialist species before restoration, and restoration seemed to decrease these numbers towards the level of pristine parts. By contrast, restoration did not affect the number of peatland specialists and their territories, which was lower in drained than in pristine parts of the peatlands. Bird communities in restored parts remained different from pristine parts in terms of community composition after restoration. Thus, despite the effect of restoration on non‐specialists, a substantially long time may be required for a recovery of the peatland bird communities. Based on our results, it seems that long‐term monitoring of the restored and pristine peatlands is needed to determine whether restoration is effective in recovering the peatland specialist bird species and bird communities in general.

Molecular Tools for Understanding Landscape Genetics and the Population Genetic Effects of Habitat Restoration on Butterflies

Habitat corridor construction is an important technique for re-establishing connections between fragmented habitats. Yet, the effectiveness of habitat corridors to increase gene flow among fragmented populations is not well studied. In 2008 and 2009, a prairie habitat corridor was created in the Green River watershed of south central Kentucky, USA to protect water quality and encourage movement of native wildlife as part of the US Environmental Protection Agency Conservation Reserve Enhancement Program (CREP). In 2008, prior to the establishment of the habitat corridor, we documented the population genetic structure of 6 butterfly species (Chlosyne nycteis, Cupido comyntas, Phoebis sennae, Phyciodes tharos, Pterourus glaucus, and Pterourus troilus) with different habitat requirements and different expected responses to corridor construction using Randomly Amplified DNA Fingerprint (RAF) markers. STRUCTURE analysis of these markers subdivided each butterfly species into 2 to 8 subpopulations in the Green River watershed. By collecting data in the early stages of habitat restoration, we have established a baseline to compare with data obtained after the corridor has matured to determine the population genetic effects on previously isolated butterfly populations and to provide information about the conservation value of habitat corridors in general.

Underwater soundscapes in near-shore tropical habitats and the effects of environmental degradation and habitat restoration

Most marine habitats have unique soundscapes and, among other potential ecological consequences, the larvae of many fish and invertebrates use habitat-specific sounds to locate appropriate settlement habitat. Anthropogenic stressors have degraded coastal ecosystems worldwide, but the effects of this degradation on the sounds emanating from deteriorated habitats are largely undocumented, as is the effectiveness of habitat restoration in reestablishing natural soundscapes. In this study, we investigated how ambient sound emanating from three near-shore, tropical habitats (subtidal mangrove prop-root habitat, seagrass, and sponge-dominated hard-bottom) in the Florida Keys, Florida (USA) varied with time-of-day and lunar phase. We also examined whether the destruction of sponge communities in hard-bottom habitats struck by cyanobacteria blooms alters the soundscape of that habitat, and if restoration of sponge communities can reestablish natural underwater soundscapes. Soundscapes of each habitat were examined using several acoustic metrics, including spectral analysis and counts of fish calls and snapping shrimp snaps. Mangrove, healthy hard-bottom, and restored hard-bottom habitats had higher soundscape spectra levels than seagrass and degraded hard-bottom whether at noon or dusk during new or full moons. Low-frequency sounds, most likely fish calls in the ~300Hz frequency range, were most prevalent in mangroves during dusk full moons. There were also higher numbers of snapping shrimp snaps in mangrove, healthy hard-bottom, and restored hard-bottom habitats than in degraded hard-bottom and seagrass beds, especially during the prominent dusk snapping shrimp chorus. Our results demonstrate that near-shore tropical habitats have unique soundscapes that are diminished by habitat degradation, but can be reestablished by habitat restoration, at least in the case of sponge-dominated hard-bottom.

Local habitat management and landscape‐scale restoration influence small‐mammal communities in grasslands

AbstractEcosystem/habitat restoration has become a major goal of international biodiversity policy. However, restorations are often limited in space or time, and we know little on whether and how restoration and management affect vertebrates. Here we assessed the local and landscape‐scale effects of habitat restoration and management on small‐mammal communities in the Egyek–Pusztakócs marsh system (Hortobágy National Park, Hungary), site of the largest active restoration of grasslands on former croplands in Europe. We live‐trapped mice, voles and shrews in spring and autumn in 2 years (four sampling periods) at two sites in six habitat types: croplands, grasslands restored 3–6 years earlier and natural grasslands. Data on 421 individuals of 12 species showed that restored grasslands were similar to croplands and natural grasslands in species richness, abundance and composition. At the local scale, management influenced abundance because there were more small mammals in unmanaged and early‐mown grasslands with taller vegetation than in late‐mown or grazed grasslands with lower vegetation, or in ploughed croplands. Elevation was also important because sites at higher elevation provided refuges during spring floods or summer droughts. At the landscape scale, the proportion of restored and natural grasslands positively affected the abundance of small mammals, whereas the proportion of linear habitats (roads, canals) had a negative effect on abundance. Our results show that management is more important than restoration per se at the local scale, which is expected for habitat generalists such as small mammals in contrast to specialists such as plant‐feeding invertebrates. However, restoration provides landscape‐scale benefits by increasing the area of grasslands that can serve as refuges for small mammals in unfavourable periods. We thus conclude that a mosaic of restored and appropriately managed grasslands with tall vegetation will provide the best chances for the persistence of small‐mammal communities in dynamic landscapes.

Selection for protection from insolation results in the visual isolation of Yellow-eyed Penguin Megadyptes antipodes nests

SummaryThe concealed and widely dispersed nests of the rare and endangered Yellow-eyed Penguin Megadyptes antipodes, or “hoiho”, have been considered to reflect an essential requirement for the visual isolation of nest sites from conspecifics. However, this may be a consequence of selection for habitat features that provide protection from insolation, thereby minimising the risk of heat stress. To help improve the understanding of hoiho nesting requirements and the effectiveness of habitat restoration, we aimed to determine whether visual isolation from conspecifics or protection from insolation is the primary driver of hoiho nest site selection. We compared the mean maximum distance of visibility and the mean percentage insolation cover of active nests with randomly sampled unused sites in flax Phormium tenax and Hebe elliptica coastal scrub at Boulder Beach, and in coastal forest at Hinahina Cove, New Zealand, 2006–2007. Results of univariate tests and the evaluation of logistic regression models suggested that the amount of insolation cover was more important than visibility for hoiho nest site selection, particularly in flax and scrub. In addition, Spearman's correlations indicated that decreasing insolation cover significantly increased the visibility of nests in the forest habitat, and had a similar effect on inter-nest distance in flax. We infer that hoiho nest site selection and distribution are influenced primarily by the location and density of micro-habitat features (particularly within 1 m of the ground) that provide optimal protection from insolation, possibly along with other important features such as a firm backing structure. Strong selection for these features results in the typical but non-essential visual isolation of nest sites from conspecifics. Restoration of nesting habitats with a relatively high density and diversity of vegetation and solid structures within 1 m of the ground may eventually provide an optimal availability and quality of suitable nest sites.

Changes in the characteristics of the bacterial community structure during habitat restoration of aquaculture sites in Xiangshan Bay

Xianshan Bay(121°25′–122° 03′E,29°05′–29°46′N) is located in the middle of Zhejiang province along the coast,a long and narrow semi-closed bay with the water area of 1 445 km2,and average water depth of 20 m.In recent years,the scale of aquaculture became larger and larger,and with pollution from land-based source,which made the environment in this bay increasingly deteriorate.During 2009–2011,we expanded the scale of macro-algae culture near the cage area of middle Xiangshan Bay to try to restore the habitat around the areas of cage culture.To assess the response,we measured the characteristics of the bacterial communities in the sediment of cage and algae culture areas using PCR,denaturing gradient gel electrophoresis(DGGE),cloning,and sequencing.The bacterial communities in the sediment environment of the cage culture area consisted primarily of 7phyla lineages of the domain bacteria.There was an increase in bacterial diversity during restoration and the dominant bacterial group changed from Acinetobacter sp.,Aminobacter aminovorans strain EE9,and Pseudomonas sp.to the uncultured actinobacterium clone HAHS13.051,Haliea sp.DSW4-37,and Ochrobactrum sp..The bacterial community in the algal culture area consisted primarily of 5 phyla lineages of the domain bacteria and the structure remained relatively stable.RDA analysis revealed that ammonia and COD are the primary factors influencing the variation in bacterial community structure.The improving trend in bacterial communities was consistent with improvements in chemical indices.Our results demonstrate that the use of macroalgae to restore the habitat of cage culture areas was effective,and suggest that bacterial community structure can be used as an index to evaluate the effectiveness of habitat restoration.

Putting watershed restoration in context: Alternative future scenarios influence management outcomes

Predicting effects of habitat restoration is an important step for recovery of imperiled anadromous salmonid populations. Habitat above three major hydropower dams in the Lewis River watershed, southwestern Washington, USA, will soon become accessible to anadromous fish. We used multiple models to estimate habitat conditions above dams and fish population responses. Additionally, we used scenario planning to predict how habitat and fish will respond to potential future trends in land use due to human population growth and riparian conservation policies. Finally, we developed a hypothetical management strategy (i.e., a set of prioritized restoration projects in specific locations within the watershed) as an example of how a fixed amount of restoration funds might be spent to enhance the success of reintroducing fish above dams. We then compared predicted outcomes from this new strategy to those of six previously modeled strategies. We estimated how the choice of the best management strategy might differ among alternative future scenarios. Results suggest that dam passage will provide access to large amounts of high-quality habitat that will benefit fish populations. Moreover, conservation of existing riparian areas, if implemented, has the potential to improve conditions to a much greater extent than restoration strategies examined, despite expected urban growth. We found that the relative performance of management strategies shifted when fish were allowed to migrate above dams, but less so among alternative futures examined. We discuss how predicted outcomes from these seven hypothetical management strategies could be used for developing an on-the-ground strategy to address a real management situation.

EPIZOOTIOLOGY OF MYXOBOLUS CEREBRALIS, THE CAUSATIVE AGENT OF SALMONID WHIRLING DISEASE IN THE ROCK CREEK DRAINAGE OF WEST-CENTRAL MONTANA

Whirling disease, caused by the myxozoan parasite Myxobolus cerebralis, remains a health threat to salmonid fish in the western United States. Although various aspects of this host-parasite system have been studied, investigations examining the overall epizootiology of whirling disease in an ecosystem are lacking. Therefore, in June 1998, studies were initiated in the Rock Creek watershed of west-central Montana and continued through 2003 to assess the intensity of infection in trout using sentinel cages stationed throughout the drainage. Additional studies determined the percentage of the annelid worm, Tubifex tubifex, releasing M. cerebralis at various localities in Rock Creek and whether there was a seasonal or daily periodicity in the release of the triactinomyxon stage of the parasite from T. tubifex. Lastly, habitat and water quality parameters, and the effects of habitat restoration on transmission of M. cerebralis, were assessed. Overall, the intensity of M. cerebralis infections in sentinel trout increased significantly throughout the drainage between June of 1998 and 2003, with the biggest jump occurring between 1998 and 1999. In addition, the range of M. cerebralis expanded considerably over the period of study. There was no strict correlation between habitat condition and the occurrence of the parasite; fish became heavily infected in optimal and marginal habitats. However, fish exposed at a locality that had the lowest habitat ranking consistently had the highest intensity of infection. The parasite has apparently caused a dramatic decline in rainbow trout densities, but the brown trout population numbers have increased, and the overall fish density remains high. Although a major habitat restoration project did not seem to have an effect on decreasing disease intensity, this was not surprising because the restored area was located just downstream from a "hotspot" of infected T. tubifex.