Restoration Of Ecological Functions Research Articles

Impact of abandonment on leaf morphology traits and nutrient utilization strategies of dominant tree seedlings in Moso bamboo forests

The restoration of ecological functions in abandoned Moso bamboo forests facilitates positive succession in evergreen vegetation. Nevertheless, there is a limited understanding regarding the leaf functional traits and nutrient utilization strategies of understory vegetation after abandonment. This study investigated the impact of abandonment duration (9 and 21 years) on leaf morphological traits, soluble sugars characteristics, carbon (C), nitrogen (N), phosphorus (P), and their ratios in dominant tree seedlings (Lithocarpus brevicaudatus and Schima superba) within Moso bamboo forests. Leaf sizes increased significantly with prolonged abandonment in both species, accompanied by a consistent decrease in leaf thickness and leaf tissue density. These morphological indices were more pronounced in L. brevicaudatus compared to S. superba (P < 0.05), and they showed a positive correlation with tree sizes. Moreover, leaf soluble sugars, C, and C: N: P ratios of both tree species decreased over duration abandonment, while N and P contents increased. Specifically, L. brevicaudatus exhibited elevated levels of fructose, glucose, N, and P, whereas S. superba displayed higher sucrose, C, and C: N: P ratios. Our findings reveal that both species, with extended abandonment, enlarged their leaf area and improved carbon utilization, facilitating adaptation to competitive resource habitats. Particularly, L. brevicaudatus exhibited a propensity to augment leaf sizes, as well as N, and P contents, suggesting a strategy to enhance carbon assimilation through additional N and P nutrient supplementation. Conversely, S. superba primarily focused on bolstering carbohydrate reserves, indicating that moderate thinning or pruning of bamboo forests could boost sunlight penetration, along with the appropriate nutrient supplementation. These insights significantly contribute to the scientific understanding necessary for the classification and management of mixed stands in abandoned bamboo forests.

Resource partitioning in a novel herbivore assemblage in South America.

Human-induced species declines and extinctions have led to the downsizing of large-herbivore assemblages, with implications for many ecosystem processes. Active reintroduction of extirpated large herbivores or their functional equivalents may help to reverse this trend and restore diverse ecosystems and their processes. However, it is unclear whether resource competition between native and non-native herbivores could threaten restoration initiatives, or to what extent (re)introduced species may influence local vegetation dynamics. To answer these questions, we investigated the diets of a novel South American herbivore assemblage that includes resident native species, reintroduced native species and introduced non-native species. We examined plant composition, diet breadth and the overlap between species to describe the local herbivory profile and the potential for resource competition. Using DNA metabarcoding on faecal samples (n = 465), we analysed the diets of the herbivore assemblage in the Rincón del Socorro rewilding area of Iberá National Park, Argentina. We compared the species richness of faecal samples, the occurrence of plant families/growth forms and the compositional similarity of samples (inter- and intraspecifically). Our results indicate species-level taxonomic partitioning of plant resources by herbivores in this system. Differences in sample richness, composition and diet breadth reflected a diverse range of herbivory strategies, from grazers (capybara) to mixed feeders/browsers (brocket deer, lowland tapir). Differences in diet compositional similarity (Jaccard) revealed strong taxonomic resource partitioning. The two herbivores with the most similar diets (Pampas deer and brocket deer) still differed by more than 80%. Furthermore, all but one species (axis deer) had more similar diet composition intraspecifically than compared to the others. Overall, we found little evidence for resource competition between herbivore species. Instead, recently reintroduced native species and historically introduced non-natives are likely expanding the range of herbivory dynamics in the ecosystem. Further research will be needed to determine the full ecological impacts of these (re)introduced herbivores. In conclusion, we show clear differences in diet breadth and composition among native, reintroduced and non-native herbivore species that may be key to promoting resource partitioning, species coexistence and the restoration of ecological function.

Different pioneer plant species have similar rhizosphere microbial communities

The interactions between rhizosphere microorganisms and pioneer plants play important roles in the restoration of ecological functions after a disturbance. Different pioneer species appear in the initial phase of ecological restoration. However, the patterns of the composition of different pioneer species shaping the microbial communities of the rhizosphere are still poorly understood. Microcosm experiments were established to compare the taxonomic and functional features of rhizosphere bacterial with fungal communities in response to plant species composition. Both bacterial and fungal communities didn’t have significant variation related to the diversity, community composition, and predicted functions between rhizosphere soils collected from treatments containing different compositions of plant species. Rhizosphere bacteria were more sensitive to the external environment than fungi. The fungal diversity exhibited a more significant relationship with the traits of different plant species compared with bacteria. Similar plant traits, especially aboveground plant traits (i.e., total coverage, and aboveground biomass), were correlated with dominant taxa and functional profiles of the both bacterial and fungal community. Furthermore, network analyses showed that Gaiellales and Ganoderma were the key bacterial and fungal taxa, respectively, which played important roles in community assembly. The composition of different pioneer species within a community had similar patterns of rhizosphere bacterial and fungal communities. The connection between plants and soil microorganisms was more likely related to plant traits instead of the species composition. Thus, the processes of plant growth and nutrient uptake, not the combinations of plant species, may be determinants of soil microbial community assemblage.

Promoting social and environmental justice to support Indigenous partnerships in urban ecosystem restoration

Urban ecological restoration typically employs western science approaches to restore degraded ecosystems. As yet, few restoration groups acknowledge the history of these degraded urban sites, despite connections, past and present, that root Indigenous Peoples (and others) in these lands. Here, we promote partnership with Indigenous communities from project inception and present two successful case studies from Aotearoa New Zealand. We specifically note that partnering and building relationships with Indigenous communities in restoration efforts require recognition of power inequalities and injustices. We consider success to include both restoration of ecological function and biodiversity and reconnection of all communities to urban ecosystems.

Disturbance intensity, disturbance extent and ocean climate modulate kelp forest understory communities

Disturbances often control community structure by removing large dominant species, allowing new species to colonize. Disturbances vary in intensity and extent, and their effects on resident communities can depend on local environmental conditions. We tested the effects of disturbance intensity and extent on different functional groups of understory species in kelp forests at 4 locations along an ocean climate gradient in Western Australia. We hypothesized that, compared to intact canopies, increasing disturbance intensities (50 and 100% of kelp removal) and extents (2, 4 and 8 m diameter) would promote light-dependent competitors (turf, foliose, articulated coralline and fucoid seaweeds) at the expense of less light-dependent functional groups (invertebrates and encrusting seaweeds). We also hypothesized that these effects would be most pronounced at warmer relative to cooler locations, where metabolic and ecological rates are faster. The first hypothesis was supported; light-dependent understory groups (turfs, in particular) increased, while less light-dependent groups (crusts in particular) decreased with increasing disturbance regimes. However, the second hypothesis was not supported; even though understory communities differed between locations and turf covers were highest at the warmest location, we found no significant interactions between locations and disturbance regimes. Importantly, our results revealed that even small-scale partial canopy loss can have significant effects on kelp-associated communities. The implied community-wide, density-dependent effects have implications for the management and conservation of kelp forests, because restoration of ecological functions must also consider the density of kelp forests, not simply their presence or absence.

Technogenic soils (Technosols) developed from mine spoils containing Fe sulphides: Microbiological activity as an indicator of soil development following land reclamation

Restoration of ecological functions by reclamation of post-mining areas stimulates soil-formation processes and initiates biological activity on the surfaces of disposal sites. The purpose of this investigation was to study the relationships between soil properties, microbiological activity and diversity in Technosols 45 years following land reclamation. The study area was located in the vicinity of the former Fe sulphide and uranium mine in Rudki village (Holy Cross Mts., Poland). The soils developed from tailings containing Fe sulphides (profile R1 and R2) and Fe sulphide and dolomite-bearing post-flotation sludge covered with loamy material (profile R3) were studied. Soil properties and enzyme (dehydrogenase, arylsulphatase, β-glucosidase, urease) activities, respiration activity (RA) and total microbial counts (TMC) were determined, as well as molecular analyses were performed. The most important soil properties influencing enzyme activities, RA and TMC were pH and soil salinity. Biological parameters were also dependent on TOC, TN, exchangeable K and available P contents. Enzyme activity, RA and TMC were significantly lower in strongly acidic and saline profile R1 than in profiles R2 and R3, which represent areas where land reclamation was successful. Moreover, a decrease of enzyme activities, RA and TMC were observed with increasing depth of soil profiles. The lower activity of arylsulphatase, β-glucosidase and RA in A horizon of profile R3 in comparison with similar horizon in profile R2 may reflect the pollution of R3 topsoil by trace elements. Molecular analysis revealed that Bacillus genus predominate in the studied profiles. Soil properties (particularly pH) that are a repercussion of reclamation works seem to be the main variables conditioning biodiversity at the bacterial strains and species level. The obtained results indicated that enzyme activity, RA and TMC are sensitive indicators of microbiological activity and can be a measure in the assesment of soil biological activity following land reclamation.

Vegetation and soil characteristics of degraded alpine meadows on the Qinghai-Tibet Pla-teau, China: A review

Alpine meadows account for 46.7% of grassland area on the Qinghai-Tibet Plateau, which is an important part of grasslands in China. Under the effects of climate change and human activities in recent years, alpine meadow has been degraded seriously. Vegetation and soil have shown different degradation trends. At large spatial scales, the degraded alpine meadows are characterized by decreases of vegetation coverage, increases of weed vegetation, soil degradation and even desertification. At the micro-scale, soil particle size, soil microorganisms, and soil enzymes in degraded alpine meadows changed. We analyzed the changes of vegetation and soil during the degradation of alpine meadow ecosystems by considering species diversity, plant community structure, plant biomass, soil physical properties, soil microorganisms, soil enzymes, and soil nutrients. We put forward some uncertainties in the current research and problems that needed further study. This review provided a scientific basis for a comprehensive understanding of the degradation mechanisms and patterns of alpine meadows, effective intervention in alpine meadow, and restoration of ecological function.

Indigenous Rights in the U.S. Marine Environment: The Stevens Treaties and Their Effects

There are few recognized indigenous rights in the U.S. marine environment. Indigenous rights in the U.S. are the product of treaties, since there are little, if any, aboriginal rights remaining. And treaty rights recognizing indigenous rights are unusual. Most concern what are known as the Stevens Treaties of the 1850s, in which the native tribes conveyed most of today’s U.S. Pacific Northwest for incidental benefits like agricultural tools and, more importantly, “the right of taking fish in common with” the incoming settlers. Several Stevens Treaty tribes have rights to harvest fish in the marine environment, including the Lummi and Makah tribes, which have been involved in quite a bit of litigation concerning the nature and scope of their rights. We examine these conflicts in this chapter. Lummi rights in the off-shore, which have been the subject of frequent court decisions over where they may be exercised, were adversely affected by a breached salmon farm net in 2017, the ramifications of which have not entirely played out as of this writing. However, they might occasion a reevaluation of salmon farming in Washington and perhaps in British Columbia as well. The Makah’s harvest rights, alone among Stevens Treaty tribes, include whaling rights. That tribe’s decades-long effort to resume whaling is part of this story as well, and we explain in some detail. Looming over all Stevens Treaty rights is the question of whether “the right of taking fish,” which includes a right to harvest half the salmon runs, including hatchery fish, also includes the right to protect the environment on which their habitat depends. That right was upheld by a federal appeals court in decades-long litigation in 2017. In 2018, the U.S. Supreme Court divided on the state's appeal, 4-4, affirming the lower court's decision without issuing an opinion. Whether other habitat-damaging activities violate the treaty right is not yet clear. Off-shore treaty rights to harvest salmon were quite influential in the signing of the Pacific Salmon Treaty between Canada and the U.S. in 1985, which reallocated international harvest rights. Tribes have also successfully convinced the U.S. government to argue for a change to the Columbia River Treaty, which affects the operation of Columbia Basin dams in both the U.S. and Canada, to include ecological function to benefit salmon migration. Such a change could have significant effects on marine harvests. That treaty is currently under renegotiation, and Canada has yet not indicated its support for an amendment that would embrace restoration of ecological function as a treaty purpose. One focus for the future could be the use by non-tribal governments to protect treaty rights in their regulatory decisions. There are several surprising recent examples of the federal, state, and local governments doing just that. The chapter discusses these developments and concludes with a discussion of what they may portend for the future in the wake of the Supreme Court's affirmation in the culverts case.

Beauty before age: landscape factors influence bird functional diversity in naturally regenerating fragments, but regeneration age does not

Effective ecological restoration actions should be able to recover ecosystem processes that influence community development in the long term. However, there is scarce information on how landscape factors promote or accelerate fauna recovery. We used a landscape framework to evaluate how functional groups respond to natural regeneration in a highly fragmented region of Atlantic Forest. Using bird functional groups sampled in 15 regenerating forest fragments, we built and ranked models using a model selection approach to test the relative effect of landscape variables on each group. Our results showed that bird community recovery is not determined by the duration of the regeneration process (i.e. forest age), but by how the species responds to the landscape context. Functional diversity and the abundance of the functional groups were mainly related to composition metrics, whereas the functional metric affected only specific groups. Our findings highlight the importance of considering the landscape level to ensure both the colonization of fauna and the restoration of ecological functions.

Restoring Ecological Function to a Submerged Salt Marsh

Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment‐slurries to increase marsh surface elevation, thus ameliorating effects of excessive inundation. Although this technique is growing in popularity, the restoration of ecological function after sediment addition has received little attention. To determine if sediment subsidized salt marshes are functionally equivalent to natural marshes, we examined above‐ and belowground primary production in replicated restored marshes receiving four levels of sediment addition (29–42 cm North American Vertical Datum of 1988 [NAVD 88]) and in degraded and natural ambient marshes (4–22 cm NAVD 88). Moderate intensities of sediment‐slurry addition, resulting in elevations at the mid to high intertidal zone (29–36 cm NAVD 88), restored ecological function to degraded salt marshes. Sediment additions significantly decreased flood duration and frequency and increased bulk density, resulting in greater soil drainage and redox potential and significantly lower phytotoxic sulfide concentrations. However, ecological function in the restored salt marsh showed a sediment addition threshold that was characterized by a decline in primary productivity in areas of excessive sediment addition and high elevation (&gt;36 cm NAVD 88). Hence, the addition of intermediate levels of sediment to submerging salt marshes increased marsh surface elevation, ameliorated impacts of prolonged inundation, and increased primary productivity. However, too much sediment resulted in diminished ecological function that was equivalent to the submerged or degraded system.