Restoration Of Plant Communities Research Articles

PLANT COMPOSITION AND SOIL PROPERTIES DURING POSTAGROGENIC EVOLUTION IN THE CIS-BAIKAL FOREST-STEPPE ZONE

Purpose. The purpose of the study was to examine the features of the restoration of plant communities and some properties of gray forest soils, including the humus state, during their post-agrogenic transformation in the conditions of the Cis-Baikal forest-steppe zone.
 Materials and methods. The study was carried out using the post-agrogenic chronosequences, including arable land, abandoned soils of different ages, and natural cenoses (meadow and forest). Traditional methods of phytocenology were applied to study the plant composition. Mixed soil samples from three trenches were collected from the former arable layer of 0–20 cm. The content of organic carbon (Corg), total nitrogen (N), and the C/N ratio, the pH(H2O) and pH(KCL) values, as well as soil density and the reserves of Corg were determined. The statistical processing of data was performed using One Way ANOVA (Sigma Plot from Windows Version 14.0).
 Results. It was shown that plant vegetation being typical for the Baikal forest-steppe zone was recovering after the cessation of plowing. At the same time, the several ruderal species were preserved in the plant composition during a long period. This specific phenomenon could be the cause for inhibition of terminal phytocenoses formation. Along with the change in the vegetation, a significant increase in the organic carbon content was revealed in the soils of chronosequences. At the later stages of post-agrogenic succession the carbon reserves in soil were 1.5 times higher than those in arable soil. The humus content in the soils increased with age of the abandoned lands, but no cardinal changes in its qualitative composition were observed. The data indicated the stable functioning of the system of humus substances in the gray forest soils of the Baikal forest-steppe zone during their post-agrogenic evolution.
 Conclusion. The results can be used for the forecast of post-agrogenic soil changes under various scenarios of land use in conditions of the Baikal region.

Meta-analysis identifies native priority as a mechanism that supports the restoration of invasion-resistant plant communities

The restoration of invasion-resistant plant communities is an important strategy to combat the negative impacts of alien invasions. Based on a systematic review and meta-analysis of seed-based ecological restoration experiments, here we demonstrate the potential of functional similarity, seeding density and priority effect in increasing invasion resistance. Our results indicate that native priority is the most promising mechanism to control invasion that can reduce the performance of invasive alien species by more than 50%. High-density seeding is effective in controlling invasive species, but threshold seeding rates may exist. Overall seeding functionally similar species do not have a significant effect. Generally, the impacts are more pronounced on perennial and grassy invaders and on the short-term. Our results suggest that biotic resistance can be best enhanced by the early introduction of native plant species during restoration. Seeding of a single species with high functional similarity to invasive alien species is unpromising, and instead, preference should be given to high-density multifunctional seed mixtures, possibly including native species favored by the priority effect. We highlight the need to integrate research across geographical regions, global invasive species and potential resistance mechanisms.

Do seeding and seedling planting result in similar restored plant communities?

AbstractAimsRestoration practitioners often face a tradeoff between low cost but risky seeding vs expensive but more reliable seedling planting to meet revegetation goals. Knowing under what environmental and management conditions direct seeding vs seedling planting benefit different species could improve restoration practice.MethodsWe compared seed emergence to planted‐seedling survival among perennial herbaceous species commonly used in restoration across eight experimental restoration sites on the Colorado Plateau, USA. We used linear models to assess relationships between emergence and survival among species, and to assess the effects of site climate and seeding pre‐treatments on those relationships.ResultsWe found that among species, emergence was positively correlated with survival in the cooler sites, meaning that species with high emergence also had high survival and vice versa, but had no relationship in the hottest sites. Furthermore, pre‐treatments to enhance soil moisture in seeded plots, specifically microtopography (pits) and mulch, also resulted in positive relationships between emergence and survival among species, while seeding without additional soil pre‐treatments did not. Seedling planting cost 14 times as much as direct seeding alone, dropping to nine times as much when pre‐treatments were combined with seeding.ConclusionsTaken together, these results suggest that investments in seedling planting at hotter dryland sites, or in creating microtopography or mulching prior to seeding across sites, are likely to promote establishment success compared to simple seeding methods in degraded dryland ecosystems. These findings also identify opportunities for hybrid seeding and planting approaches that balance tradeoffs between risk and cost, respectively.

A nontarget, disturbance‐resilient native species influences post‐fire recovery and multiphasic herbicide‐seeding outcomes in drylands threatened by exotic annual grasses

Native species that are abundant and persistent across disturbance‐succession cycles can affect recovery and restoration of plant communities, especially in drylands. In the sagebrush‐steppe deserts of North America, restoring deep‐rooted perennial bunchgrasses (DRPBGs) is key to the strategy for breaking an increasingly problematic cycle of wildfire promoted by exotic annual grasses (EAGs) and displacement of perennials by post‐fire increases in EAGs. We asked how Sandberg bluegrass (Poa secunda, POSE)—a common native grass that shares traits with EAGs such as resilience to disturbance and rapid, shallow‐rooted, early season growth—(1) recovered after wildfire, (2) responded to different combinations of native‐plant seedings of DRPBGs and EAG‐targeting herbicides; and (3) in turn, related to DRPBG recovery. In repeated sampling of up to approximately 2,000 plots spanning 113,000 burned hectares, POSE was initially more abundant than DRPBGs until POSE began to decline 5 years post‐fire, and POSE was marginally affected or unaffected by restoration treatments targeting DRPBGs or EAGs. In comparison, EAG cover decreased 8–16% where preemergent herbicide was sprayed and DRPBG cover increased 3–9% where they were drill‐seeded, and the greatest EAG reductions and DRPBG increases were seen where seeding and herbicides were combined in a time‐staggered fashion. Treatments had less target effects where POSE cover was high (>18%), which is also where EAG cover was scarcer and DRPBG cover greater, regardless of post‐fire interventions. Consideration of the ecological role of disturbance‐resilient species with ruderal characteristics that match traits of key invaders may improve the efficiency and effectiveness of restoration interventions.

Seedling responses to moderate and severe herbivory: a field-clipping experiment with a keystone Mediterranean palm.

Plant-ungulate interactions are critical in shaping the structure of Mediterranean plant communities. Nevertheless, there is a dearth of knowledge on how plant intrinsic and extrinsic factors mediate the sign and strength of plant-ungulate interactions. This is most relevant when addressing natural or assisted restoration of plant communities in human-disturbed areas. We conducted field-clipping experiments simulating how different intensities of ungulate herbivory may affect the natural regeneration and establishment of the Mediterranean dwarf palm (Chamaerops humilis), a keystone species in Mediterranean ecosystems. We quantified seedling survival and size in two human-disturbed sites (SW Spain) where wild and domestic ungulates exert high herbivory pressure on vegetation. Severe clipping and seedling aging reduced rates of seedling survival. In contrast, moderate clipping did not affect seedling survival, suggesting a certain degree of C. humilis tolerance to herbivory. Severe clipping reduced seedling height strongly but not seedling diameter, and these effects seem to have decreased seedling survival. Nurse shrubs increased seedling size, which likely improved seedling survival. We also found seedling compensatory growth which varied between study sites. Field-clipping experiments can help disentangle effects of plant extrinsic and intrinsic factors on the sign and strength of plant-ungulate interactions and their ecological consequences on the dynamics of human-disturbed ecosystems. We call attention to the importance of appropriately managing scenarios of severe herbivory and summer droughts, particularly frequent in Mediterranean ecosystems, as synergic effects of such key drivers can negatively affect the structure and dynamics of plant communities and endanger their conservation.

Relationships among rare plant communities and abiotic conditions in managed spring‐fed arid wetlands

Spring‐fed wetlands within arid and semiarid systems are hotspots for endemism and distribution of rare plants. Interactions among groundwater and the geomorphic and climatic features of the setting control the abiotic conditions, particularly soil salinity and moisture, that support these plants. However, water uncertainty and land use change challenge the persistence of conditions necessary to support rare plant communities. Wetland management can be implemented to sustain abiotic processes that support rare plant communities, but key information is needed to guide management practices. In this study, we evaluate the relationships of rare plants to abiotic conditions in a managed spring‐fed arid wetland. Soil salinity and moisture conditions were monitored and related to the presence and abundance of rare plants within management units. Soil salinity and moisture variability were related to groundwater dynamics near springs, but wetland management influenced variability in seasonally flooded areas. Permanently saturated conditions and low soil salinities during the spring season supported higher plant diversity and the presence and greater abundance of rare plants. Rare plant presence and abundance were negatively related to low soil moisture, particularly in the summer. Results indicate that increases in soil salinity during the early establishment of plants may affect their distribution and abundance, an important management consideration in arid landscapes and hydrologically altered systems. Our findings inform the restoration and management of rare plant communities and contribute to the management of spring‐fed arid wetlands.

Drivers and mechanisms of spontaneous plant community succession in abandoned Pb[sbnd]Zn mining areas in Yunnan, China

The drivers and mechanisms underlying succession and the spontaneous formation of plant communities in mining wasteland remain largely unknown. This study investigated the use of nature-based restoration to facilitate the recovery of viable plant communities in mining wasteland. It was found that scientific analyses of spontaneously formed plant communities in abandoned mining areas can provide insights for nature-based restoration. A chronosequence (“space for time”) approach was used to establish sites representing three successional periods with six successional stages, and 90 quadrats were constructed to investigate changes in plant species and functional diversity during succession in abandoned PbZn mining areas. A total of 140 soil samples were collected to identify changes in soil properties, including plant nutrient and heavy metal concentrations. Then, this paper used structural equation models to analyze the mechanisms that drive succession. It was found that the functional diversity of plant communities fluctuated substantially during succession. Species had similar functional traits in early and mid-succession, but traits tended to diverge during late succession. Soil bulk density and soil organic matter gradually increased during succession. Total nitrogen (N), pH, and soil Zn concentrations first increased and then decreased during succession. Concentrations of Mn and Cd gradually decreased during succession. During early succession, soil organic matter was the key factor driving plant colonization and succession. During mid-succession, soil Zn functioned as an environmental filter factor limiting the rates of succession in mining wasteland communities. During late succession, soil bulk density and competition for nutrient resources contributed to more balanced differentiation among plant species. This thesis proposed that a nature-based strategy for the stabilization of abandoned mining lands could facilitate effective plant community restoration that promotes ecosystem services and functioning.

Interacting ecological filters influence success and functional composition in restored plant communities over time.

A trait-based community assembly framework has great potential to direct ecological restoration, but uncertainty over how traits and environmental factors interact to influence community composition over time limits the widespread application of this approach. In this study, we examined how the composition of seed mixes and environment (north- vs. south-facing slope aspect) influence functional composition and native plant cover over time in restored grassland and shrubland communities. Variation in native cover over 4 years was primarily driven by species mix, slope aspect, and a species mix by year interaction rather than an interaction between species mix and slope aspect as predicted. Although native cover was higher on wetter, north-facing slopes for most of the study, south-facing slopes achieved a similar cover (65%-70%) by year 4. While community-weighted mean (CWM) values generally became more resource conservative over time, we found shifts in particular traits across community types and habitats. For example, CWM for specific leaf area increased over time in grassland mixes. Belowground, CWM for root mass fraction increased while CWM for specific root length decreased across all seed mixes. Multivariate functional dispersion remained high in shrub-containing mixes throughout the study, which could enhance invasion resistance and recovery following disturbance. Functional diversity and species richness were initially higher in drier, south-facing slopes compared to north-facing slopes, but these metrics were similar across north- and south-facing slopes by the end of the 4-year study. Our finding that different combinations of traits were favored in south- and north-facing slopes and over time demonstrates that trait-based approaches can be used to identify good restoration candidate species and, ultimately, enhance native plant cover across community types and microhabitat. Changing the composition of planting mixes based on traits could be a useful strategy for restoration practitioners to match species to specific environmental conditions and may be more informative than using seed mixes based on growth form, as species within functional groups can vary tremendously in leaf and root traits.

Mechanisms for the construction of plant communities in the Gurbantunggut Desert, China

Analysis of the phylogenetic structure of a community based on the phylogenetic relationships among species in the community can reflect the ecological process of community composition and determine the mechanism of plant community construction. In this study, we analyzed the characteristics of the phylogenetic structure and diversity of plant communities in the Gurbantunggut Desert and their interactions with soil factors and explored the mechanisms of species maintenance in the communities. The results showed that the ecological traits of plants were conserved, habitat filtering was the primary process affecting plant communities, and the diversity of phylogeny was ranked as fixed dunes > semifixed dunes > mobile dunes. At different slope positions within the dune, there is greater phylogenetic diversity at the bottom and lower slope, and habitat filtering dominates community construction, with the dominant role of habitat filtering in the community diminishing as the slope position rises. The phylogenetic diversity of plant communities of different life types is ranked as short-lived plants > small trees and shrubs > annual and perennial herbs. On the bottom and lower slopes, short-lived plants and annual and perennial herbaceous communities are mainly influenced by habitat filtering. Habitat filterability decreased with increasing slope position. On the upper slopes and at the top, competitive exclusion effects between small trees and shrubs dominated. Our analysis shows that soil water content and organic carbon affect phylogenetic diversity mainly by influencing community species richness and that the interaction between soil water content, grain size and plant diversity leads to clustering of species with similar soil preferences, which in turn affects the phylogenetic structure of the community. In addition, the change from habitat filtering to intraspecific competition in plant community construction from the bottom to the top of the slope is mainly influenced by short-lived plant communities, and this type of plant needs to be given priority consideration in the conservation and restoration of desert plant communities.

Common, showy, and perennial species dominate a restoration species pool

Native seed vendors are a primary source of germplasm for restoration projects; however, most plant species are not commercially available. Preferences in the types of species that vendors grow and sell may limit the similarity between reference communities and reconstructed ones established from seed mixes. We tested whether a restoration species pool shows preference for certain groups of species, focusing on the Ozark Highland Ecoregion (midcontinent United States). We identified the pool of 1,082 candidate herbaceous plant species appropriate for restoration projects on upland habitats in this region, and then surveyed nine regional seed vendors to assess their commercial availability. Commercially available species were more likely to be forbs over graminoids, perennials over annuals, and common species with larger ranges and moderate conservatism scores. Within forbs, taller species and those with longer bloom durations were favored. Species with affinity to open habitats (e.g. grassland) were more likely to be available from multiple vendors than those from woodlands and forests. Encouragingly, 454 (42%) of the species in this regional pool were available. However, this means that most species in the region are not likely to be included in seed mixes, unless they are hand‐collected from remnant populations. This restoration pool favors common and showy species, which is consistent with previous studies showing these kinds of species tend to dominate seed mixes and restored plant communities. We identified 39 species that were not available from any of the vendors surveyed, which we recommend as candidates for expansion of the Ozark restoration species pool.

Changes of nutrients and microbial communities in recovery process of abandoned rare earth tailings

Rare earth element (REE) mining has wrought severe ecosystem destruction, particularly in the loss of carbon (C), nitrogen (N), and phosphorus (P). Furthermore, its effects on nutrient recovery characteristics and associated microbial abundance are still poorly understood. In this study, an investigation was conducted to determine C, N, and P recovery patterns and microbial communities in abandoned REE mining tailings with different abandoned durations of 1.5 (1.5-Y), 7 (7-Y), 10 (10-Y), and 14 (14-Y) years and at an unmined site (the control group) in Jiangxi Province, China. Longitudinal tailing delamination at each site was investigated in 0–15 (layer 1) and 15–30 (layer 2) cm tailing layers. During the abandoned duration of REE tailings, C and P in layer 1 continued to recover from 1.62 to 8.51 g kg-1 and from 0.71 to 1.94 g kg-1, respectively; N losses of 0.60 and 0.22 g kg-1 occurred at the 1.5-Y and 10-Y sites, while N in layer 1 slightly increased at the 14-Y site. Mesorhizobium, Methylosinus, Bradyrhizobium, Pseudomonas, and Azospirillum were dominant bacteria at the 14-Y site and in the control. The relative abundances of N-fixing bacteria Mesorhizobium (32.94%), Sinorhizobium (0.24%), Frankia (0.71%), and Burkholderia (2.38%) at the 14-Y site were 1.33–3.97 times those in the control (24.19%, 0.18%, 0.32% and 0.60%, respectively), which was helpful for tailing N recovery. At the 14-Y site, Tylospora (50.24%), Luellia (11.02%), Tomentella (6.94%), and Chaetomium (4.34%) were the dominant fungal genera, while Tylospora (56.93%), Suillus (11.45%), and Penicillium (6.78%) predominated in the control. The relative abundance of the P-dissolving fungus Aspergillus at the 14-Y site (0.42%) was 4.2 times that in the control (0.1%), which may lead to the improved tailing P solubility. At the 14-Y site, woody plants such as Pinus massoniana and native pioneering herbs and ferns such as Dicranopteris dichotoma and Nephrolepis auriculata probably invaded from adjacent areas. This study unraveled the natural restoration of plant and microbial communities along with soil nutrient changes in abandoned REE tailings, thus providing a novel insight into ecological recovery and restoration after mining.

Restoration of woody plant communities in red pine plantations on abandoned agricultural land in northern Minnesota, USA

While tree plantations have increased globally, there is growing interest in restoring plantations to native ecosystems. Restoration efforts may be more successful when tree species native to original ecosystems are planted instead of species that are either introduced or native, but off site.Plantations of red pine (Pinus resinosa Ait.) in the western Great Lakes region of North America were commonly established on red pine sites, often after agricultural clearing and abandonment. Red pine is the only species in the overstory, compared to 10 or more species in red pine woodlands. Plantations differ in structure from woodlands, being single-aged versus multi-cohort and having high and spatially-uniform density versus lower and variable density.Our aim was to contrast changes in structure and woody species composition over a 15-year period in response to two silvicultural approaches in red pine plantations on the Red Lake Wildlife Management Area in northwestern Minnesota, USA. Approaches included: 1) uniform thinning followed by a dispersed retention harvest (dispersed treatment) and 2) variable density thinning followed by an expanding gap irregular shelterwood (aggregated treatment).Basal area of trees ≥10 cm dbh was reduced similarly in both treatments to 9 m2 ha−1, but there was high within-stand variability (coefficient of variation) in the aggregated treatment (>100%) compared to the dispersed treatment (20%). Understory woody species abundance increased with both treatments, including sapling, large regeneration, and small regeneration layers, with >100% increases. In the sapling layer, the increased abundance (to 2.5 m2 ha−1) reflected new recruitment into this layer, as there were few saplings before treatment (<0.5 m2 ha−1). By year 15, the majority of saplings were canopy capable species, while lower regeneration layers contained mixtures of canopy trees, sub-canopy trees, and shrubs.Composition in the understory changed, but was similar between treatments, including increases in woody shrubs in the small regeneration layer and increases in red pine regeneration in the large regeneration layer. The sapling layer had increased importance of several native tree species, especially in the aggregated treatment.Both of our silvicultural approaches moved structurally simple, species poor red pine plantations toward a condition reflecting native red pine woodlands, which had mixed-species composition and variably open canopy cover. The treatment using variable density thinning and an irregular shelterwood resulted in greater spatial variability of structure and greater importance of shade-intolerant tree species, both characteristics of native woodlands. While focused on red pine, this approach should have application to conifer restoration more generally.

Restoring Soil Cover and Plant Communities with Arbuscular Mycorrhizal Fungi as an Essential Component of DSS for Environmental Safety Management in Post-Industrial Landscapes

Large areas become unsuitable for full-fledged life after mining activity. To improve the state of environmental safety of post-industrial landscapes and the rational use of disturbed territories, a Decision Support System (DSS) should be created. This system should also contain proposals for restoring the soil cover and plant communities that are proposed in this article. The purpose of this study is to determine the influence of arbuscular mycorrhizal fungi on the process of vegetation formation in the post-industrial landscape of a sulfur quarry. During reclamation works in human-made ecotopes, vegetation has already formed there in a certain way due to natural succession processes. We assessed the level of vegetation self-restoration and, on the basis of the obtained data, the need and direction of phytoreclamation in relation to specific ecotopes. The set of restoration of soil cover and plant communities makes it possible to solve the problem of reusing post-industrial landscapes. The positive effect of the treatment of seedlings with a spore remedy of arbuscular, mycorrhizal fungi on the studied breeds’ height increase was observed. In the process of the revitalization of disturbed landscapes through the mycorrhization of planting material, there is a tendency to restore and increase phytodiversity at the floristic and coenotic levels.

Rhizosphere Microorganisms and Soil Physicochemical Properties of Restored Wetland Plant Communities at Cutting Slash of Populus deltoides in Dongting Lake

Rhizosphere microorganisms and soil physicochemical properties play a vital role in the natural restoration of plant communities. However, the mechanism of action between rhizosphere microorganisms and soil factors interact during natural restoration in plant communities is still unknown. Therefore, more attention is needed in this area based on typical vegetation, which supports the restoration of the structure and function of wetland ecosystems. Carex spp. and Artemisia selengensis communities are typical renewal wetland plant communities at cutting slash of Populus deltoides. In the current study, plots containing Carex spp. and Artemisia spp. in the slash were investigated, and an area of P. deltoides plantation on a lake shore was sampled as a control to navigate the rhizosphere microorganisms and soil physicochemical properties of the restored wetland plant community. The results revealed that the richness and diversity indices of the fungal community in the Carex spp. community were higher than those in the A. selengensis and P. deltoides undergrowth communities. Ascomycota was the dominant phylum in the soil of Carex spp. community whereas Basidiomycota was the dominant phylum in the A. selengensis community. The richness and diversity indices of the rhizosphere bacterial community in the control were higher than those in communities of Carex spp. and A. Selengensis. Proteobacteria and Actinobacteria were the dominant phyla of the rhizosphere bacterial community in the control plot. Soil water content (WC), proportion of clay (CY), and nutrient content, as well as catalase activity (CAT) in the soil of Carex spp. community were the highest, whereas those in the control were the lowest. Conversely, the bulk density (BK) and proportion of gravel in the control plot were the highest. RDA found that the CY, organic matter (OM), ammonium nitrogen (AN) and nitrate nitrogen (NN) content in the soil were the key factors affecting the structure and composition of the rhizosphere microbial community.

Plant Traits Guide Species Selection in Vegetation Restoration for Soil and Water Conservation.

Great efforts have been made to improve the soil and water conservation capacity by restoring plant communities in different climatic and land-use types. However, how to select suitable species from local species pools that not only adapt to different site environments, but also achieve certain soil and water conservation capacities is a great challenge in vegetation restoration for practitioners and scientists. So far, little attention has been paid to plant functional response and effect traits related to environment resource and ecosystem functions. In this study, together with soil properties and ecohydrological functions, we measured the seven plant functional traits for the most common species in different restoration communities in a subtropical mountain ecosystem. Multivariate optimization analyses were performed to identify the functional effect types and functional response types based on specific plant traits. We found that the community-weighted means of traits differed significantly among the four community types, and the plant functional traits were strongly linked with soil physicochemical properties and ecohydrological functions. Based on three optimal effect traits (specific leaf area, leaf size, and specific root length) and two response traits (specific leaf area and leaf nitrogen concentration), seven functional effect types in relation to the soil and water conservation capacity (interception of canopy and stemflow, maximum water-holding capacity of litter, maximum water-holding capacity of soil, soil surface runoff, and soil erosion) and two plant functional response types to soil physicochemical properties were identified. The redundancy analysis showed that the sum of all canonical eigenvalues only accounted for 21.6% of the variation in functional response types, which suggests that community effects on soil and water conservation cannot explain the overall structure of community responses related to soil resources. The eight overlapping species between the plant functional response types and functional effect types were ultimately selected as the key species for vegetation restoration. Based on the above results, we offer an ecological basis for choosing the appropriate species based on functional traits, which may be very helpful for practitioners involved in ecological restoration and management.

Addressing barriers to proactive restoration of at‐risk sagebrush communities: a causal layered analysis

Restoration success in degraded rangelands often depends on a site's resilience to disturbance and resistance to invasive plants. Because it is more difficult to restore plant communities after they are dominated by invasive species, a potential approach is proactive restoration in sites at risk of crossing degradation thresholds (e.g. initiating restoration prior to invasive grass dominance). When developing a new restoration approach, it is important to consider operational feasibility, including social, budgetary, and environmental factors. Accordingly, we studied influences within land management agencies on the adoption of a specific proactive restoration approach: out‐planting native grass and forb seedlings into sagebrush stands before they are dominated by cheatgrass (Bromus tectorum). Managers from federal and state land management agencies across the Great Basin, U.S.A, were interviewed regarding perceived feasibility of these practices. Twelve in‐depth interviews were conducted, and responses were analyzed using a qualitative method, causal layered analysis, not previously applied in a land management context. In the most superficial (litany) layer, cost and scale were prominent. The next (systemic) layer was framed by policy and bureaucracy limitations as well as technical barriers to implementation. In the third (worldview) layer, lack of a proactive management tradition within agencies represented a principal barrier. In the deepest (myth/metaphor) layer, the central belief is that human intervention should be used to protect ecosystem services only after they are disrupted due to human activity. Based on the different obstacles found at each level, we suggest ways to overcome the barriers detected.

Impacts of invasive ants on pollination of native plants are similar in invaded and restored plant communities

Ants are amongst the most successful invaders worldwide and can markedly modify invaded communities through biotic interactions. Invasive ants, for example, can compete with native pollinators for resources, act as legitimate pollinators, or disrupt plant-pollinator mutualistic interactions, thereby affecting native plant reproduction. Ecological restoration aims to mitigate the impact of invasive species and restore ecological communities and ecosystem functioning. Here we investigated the combined effects of two invasive ant species, the yellow crazy ant (Anoplolepis gracilipes) and white-footed ant (Technomyrmex albipes), on the pollination and reproduction of native plants in the context of a large-scale plant community restoration experiment. We conducted ant exclusion experiments and pollinator observations to obtain data on plant reproduction and pollination of four plant species. The experiments were conducted across eight granitic inselbergs on the island of Mahé, Seychelles, four of which are undergoing restoration since 2011 and four remained as invaded control sites (unrestored). Our findings indicate that native plants on Seychelles’ inselbergs relied primarily on flying flower visitors for pollination, considering that the contribution of ants to fruit set was generally small and substantially lower than that of flying pollinators. Moreover, while flying pollinators approached flowering plants irrespective of invasive ant presence, the number of probed flowers per visit was reduced, in both restored and unrestored communities. Therefore, native plant reproduction was negatively affected by the presence of invasive ants and this effect was similar in restored and unrestored plant communities. Our research suggests that invasive ants may contribute to changes in plant communities by deterring legitimate pollinators of native plants, an impact that is unlikely to be alleviated through early stages of ecological restoration.

Variation in Species Composition, Structural Diversity, and Regeneration Along Disturbances in Tropical Dry Forest of Northern India

Understanding disturbances is crucial for preventing forest degradation and resolving vegetation loss which remain to be a major concern. The present study was to evaluate the vegetation dynamics of different disturbed forest stands, based on cumulative disturbance index score in Vindhyan highlands, India. Our findings demonstrated that the mean tree density was greater in least disturbed (56.24±1.44 ha–1) than in highly disturbed (53.28±2.67 ha–1) and moderately disturbed (50.27±0.94 ha–1) forest stands. Shannon, Simpson, Evenness, Margalef, and β-diversity indices differed significantly amongst the three disturbed stands. The regeneration potential of tree species was found to be good (35.08%), fair (16.42%), and poor to no regeneration (48.5%) across the three stands, in which Diospyros melanoxylon, Syzygium heyneanum, and Holarrhena antidysenterica were shown to have strong regeneration capacity. Principal component analysis revealed that the first component (pc1) explained 45.3% variance, while the second component (pc2) elucidated 20.1% variance in both disturbances and life-form wise distribution with a cumulative score of 65.4%. Our findings would be helpful to understand how different disturbance–regeneration combinations influence the successful regeneration of tree seedlings as well as how variations in compositional diversity will impact the vegetation dynamics and restoration of plant community in dry tropics.

Reintroducing Vascular and Non-Vascular Plants to Disturbed Arctic Sites: Investigating Turfs and Turf Fragments

<h3>ABSTRACT</h3> Disturbed low-Arctic environments provide many challenges for ecological restoration, from harsh climates and remote locations to limited knowledge on plant establishment and successional pathways within tundra ecosystems. Due to limited commercially available materials for restoration of native low-Arctic plant communities, transplantation may provide an effective technique for revegetation in these difficult-to-restore environments. In this study, whole-turfs and shredded turfs were harvested from undisturbed upland-heath tundra near Rankin Inlet, Canada, and transplanted onto nearby disturbed gravel quarries to investigate species survivability and development of upland-heath vegetative communities. Two years following transplantation, turfs were found to maintain 85% of the initial vegetative cover and 91% of the initial species richness, with expansion up to 8 cm into the surrounding substrate, and production of seeds and spores. Although shredded turfs were unable to significantly establish vascular species, evidence suggests a shredded turf may establish non-vascular plant cover over a larger area than intact turfs, if given greater protection from environmental stressors. Our results demonstrate that whole-turfs are resistant to harvesting and transplantation stresses, flooding, drought, and poor soil conditions, and are an effective means of species transfer promoting development of vegetative cover on disturbed substrates. High species survivability indicates that turfs have the potential to provide disturbed areas with a wide array of native species, critical for the development of sustainable and self-organizing assemblages of native vegetation.

Changes in the stream discharge in the forest-steppe zone in the XXI century under the environmental regime (based on the research of the dynamics of the length of the channel network of elementary watercourses on the territory of the “Sengileevskie Mountains” National Park Ulyanovsk region, Russia))

The article presents the results of researching changes in the stream discharge in the forest-steppe zone in the XXI century in the conditions of the environmental regime. Due to the lack of data on the stream discharge within the researched area in previous years, the length of the channel network is considered as an indicator of water content – an indicator that generally correlates with the value of the length of the channel network. Elementary watercourses are taken as the object of research, since in short periods they are able to show high variability under the influence of external conditions, especially if it is necessary to establish the influence of specific local factors. The research was conducted on the territory of the “Sengileevskie Mountains” National Park, which lies within the Volga landscape region and the Low Volga region in the forest-steppe zone. This territory exists in the conditions of the nature protection regime and has a high forest cover. The research was based on the materials of the expedition work carried out in the summer of 2022. and the results of geoinformation analysis of topographic maps reflecting the position of the sources of elementary watercourses in 2001. As a result of the expedition work, the length of the channels of elementary watercourses as of 2022 has been established, the indicator of the change in the length of their channels in the XXI century – from 2001 to 2022 has been calculated. The fact of the multidirectional dynamics of the length of the channel network of elementary watercourses is established. In the conditions of the nature protection regime established at the beginning of the XXI century, against the background of the restoration of the landscapes of the researched territory, there is an increase in the length of the channel network of elementary watercourses, which has a correlation with the areal indicators of the restoration of natural plant communities – forests and meadows.