Restoration Of Plant Communities Research Articles

Restoration of plant communities on various dump substrates

The results of field studies in 2018 and 2019 at the pilot production site on the territory of the external dump “Zarechny” of JSC SUEK-Kuzbass are presented. The ecological and coenotic characteristics of plant communities formed in the areas with the filling of the fertile soil layer (FSL) (0.5 m thickness), with the application of potentially fertile rocks (PFR) (1 m thickness), in the area with the filling of technogenic eluvium, as well as in the area with the layer-by-layer filling of PFR (0.6 m thickness) and FSL (0.4 m thickness) were studied. Geobotanical descriptions were carried out according to standard methods, taking into account iterations. It is established that in the first years after the end of the formation of the pilot production site, the number of herbaceous plant species increases in all areas. However, the use of lithogenic resources in the frame of reclamation accelerates the development of plant communities on man-made landscapes, but does not allow reaching the stages of zonal formations.

The impact of a recultivation layer on the restoration of plant communities

Areas of coal mining dumps naturally overgrowing with vegetation in the dry-steppe (Khakassia), forest-steppe (Krasnoyarsk Krai, Kansk-Achinsk Fuel and Energy Complex, KAFEC) and subtaiga (Kemerovo region, Kuzbass) subzones were investigated. The environmental and cenotic characteristics of herbaceous communities were studied in experimental sites following the application of a fertile soil layer and in technogenic eluviums without soil improvers. The application of a fertile soil layer was found to increase both the species abundance and the projective cover of zonal species. Thus, the presence of a humus horizon promotes the formation of herbaceous ecosystems. However, this is not an unconditional factor that these ecosystems would reach the stage of zonal formations.

ПОЧВООБРАЗУЮЩЕЕ ЗНАЧЕНИЕ ВЫНОСЯЩЕЙ (ПЕРЕОТЛОЖНОЙ) ДЕЯТЕЛЬНОСТИ КРОТА ЕВРОПЕЙСКОГО (TALPA EUROPAEA, L) В ТАЕЖНОМ БИОГЕОЦЕНОЗЕ

Кротовые выбросы (кротовины) представляют собой перемешанные поверхностные слои почвы, в которых наблюдается положительная динамика основных физико-химических свойств почвы – снижение плотности, влажности, кислотности и увеличение содержания органического вещества (гумуса), особенно в первые 3 месяца после образования выбросов. В результате исследований были определены наиболее предпочитаемые для крота европейского (Talpa europaea) биогеоценозы Вологодской области. Наиболее заселенными оказались лесные биогеоценозы с влажными участками на опушках леса и на пограничных лесных территориях. Также крот предпочитает смешанные молодняки на вырубках. Одним из лимитирующих факторов выносящей деятельности крота является гранулометрический состав почвы. Выявлено, что крот охотнее осваивает территории с легкими и средними суглинками, в то время как на участках с более легкими супесчаными и тяжелыми суглинистыми почвами активность крота снижается. Получены данные о площади повреждений кротом почвенного покрова в разных лесных биоценозах. Одним из положительных факторов деятельности крота является создание благоприятных условий для восстановления растительных сообществ на антропогенно-нарушенных территориях (вырубках) в результате качественных улучшений физико-химических свойств почвы.

Floristics of Difficult Creek Natural Area Preserve: a Piedmont mafic woodland complex in Halifax County, Virginia, U.S.A.

The 331-hectare (819-acre) Difficult Creek Natural Area Preserve (DCNAP) was established in Halifax County, Virginia to protect and manage habitat for rare vascu-lar plant species and animals, and to restore plant communities. Mafic metavolcanic rocks of the Virgilina Formation and felsic metavolcanic and metasedimentary rocks of the Aaron Formation comprise the geologic units on the preserve. The Virgilina-derived soils have high shrink-swell potential, a dense hardpan layer, relatively high base status, and a significant gravelly or stony component; these soil conditions support the highest density of rare plant species known on the preserve. The first noteworthy vascular plant species were documented from the property in 1972 by botanist Alton Harvill of Longwood University, but detailed investigations of the flora did not begin until the site was revisited by the second author in 1993. Rare plant inventory has been the primary focus of botanists since that time. In 2001, the property was acquired by the Virginia Department of Conservation and Recreation, Division of Natural Heritage (DCR) and dedicated as a state Natural Area Preserve, at which point active management for natural communities and associated rare species was initiated. Since the rare plants on site thrive in open woodland or savanna-like conditions, prescribed burns and timber harvests have been used by DCR stewards to restore habitat after decades of fire suppression and conversion of hardwood stands to loblolly pine plantations. In 2018, a thorough floristic study was initiated to highlight the significance of this flora beyond the documentation of rare plants. The two-year inventory documented 653 plant taxa, comprising 326 genera in 106 families. Fourteen of these species are of conservation concern at the global or state level; an additional 12 taxa are considered uncommon and of potential conservation concern (Townsend 2019). These rare or uncommon species are components of two globally rare plant communities. In addition, the globally rare lepidopteran, Erynnis martialis (Mottled Duskywing), occurs on the preserve, the only extant population known in Virginia. Due to agricultural impacts and widespread fire exclusion, few analogs to this flora exist within the southern Piedmont of Virginia.

Ecosystem restoration is risky … but we can change that

The forthcoming UN Decade of Ecosystem Restoration brings the challenge of massively increasing restoration efforts to halt and reverse environmental degradation. This challenge must move beyond a focus on the size and number of projects to a focus on how those projects are designed and implemented. Approaches based on restoring the fundamental ecological processes that lead to self-sustaining ecosystems are essential.

Getting to the root of restoration: considering root traits for improved restoration outcomes under drought and competition

A foundational goal of trait‐based ecology, including trait‐based restoration, is to link specific traits to community assembly, biodiversity, and ecosystem function. Despite a growing awareness of the importance of belowground traits for ecological processes, a synthesis of how root traits can inform restoration of terrestrial plant communities is lacking. We reviewed and summarized existing literature focused on root traits in relation to plant performance measures (i.e. survival, establishment, productivity) in the contexts of drought and competition (including invasion). Root traits related to belowground resource acquisition (e.g. high specific root length, deep roots) are frequently related to drought avoidance (i.e. a plant strategy based on optimizing water uptake to maintain function), whereas studies relating root traits to drought tolerance (i.e. a plant strategy that allows plants to withstand low hydration) remain limited. More studies have linked root traits to plant competitive effects (i.e. the influence a plant has on neighbors) than to competitive responses (i.e. a plant's ability to resist the effects of neighbors). Because plants with acquisitive traits decrease resources to the detriment of neighbors, root traits associated with rapid resource acquisition (e.g. high specific root length) may be important for understanding competitive effects. Albeit more limited, research suggests root traits associated with resource conservation or stress tolerance (e.g. high root tissue density, high root diameter) may elucidate mechanisms related to competitive responses. Re‐vegetation outcomes may be improved by considering root traits, but only if clear links are made between traits and plant performance in varied contexts.

Seeding is not always necessary to restore native early successional plant communities

Restoration of native early successional plant communities in the eastern United States is a conservation priority because of declining populations of associated plants and wildlife. Restoration typically involves seeding native species and is often fraught with problems including weedy competition, expensive seed, and slow establishment. Pairing seed bank response with strategic herbicide applications may be an alternative approach for restoring these plant communities. We compared early successional plant communities established by seeding (SD) paired with selective herbicide use to natural revegetation (NR) from the seed bank paired with selective herbicide use at 18 locations that were previously row‐crop or tall fescue (Schedonorus arundinaceus) fields in Tennessee, Alabama, and Kentucky, the United States. We did not detect differences in species diversity and richness, coverage of non‐native grasses and forbs, or number and coverage of native flowering forbs by season between NR and SD treatments at tall fescue or fallow crop sites. Species evenness was greatest in NR and coverage of native‐warm‐season grasses in SD. Species richness and coverage of native forbs were least in untreated tall fescue units (CNTL). More flexibility to use herbicides with NR reduced coverage of sericea lespedeza (Lespedeza cuneata) in NR units compared to SD units at tall fescue sites. NR was 3.7 times cheaper than seeding. Land managers should consider using an NR approach to establish native early successional plant communities.

The driving mechanisms for community expansion in a restored Carex tussock wetland

Community expansion and succession are important processes in wetland ecosystems. Studying the expansion of restored plant communities contributes to understanding the dynamic evolution of wetland restoration, and is of great significance. A restored Carex appendiculata tussock wetland in Sun Island was selected for study and a field survey and 3S technology carried out to identify Carex tussock spatial distribution and expansion processes. We also analyzed relationships between the Carex community and environmental variables to clarify the main drivers of community expansion. The C. appendiculata tussock community expanded 29.91 m to southwest and 13.27 m to the east, respectively, with a total expansion area of 722 m2. Carex tussocks in the expansion area had significantly higher leaf area, individual plant biomass, hummock diameter and volume, which were positively correlated with soil water content and water depth. Redundancy analysis (RDA) demonstrated that water depth was the major driving force for Carex tussock community expansion. Additionally, interspecific competition between Phragmites australis and Carex tussock may inhibit Carex community expansion. Moreover, as water depth affected the development and expansion of Carex tussocks, hydrological regulation can be used to accelerate the recovery and restoration of Carex tussock wetland. This study provides a specific technology for the restoration of Carex tussock wetland.

Plant community recovery following Sericea lespedeza (Lespedeza cuneata) removal: testing for a soil legacy effect

Restoration of plant communities can be hindered by the legacy of previously established invaders, despite their physical removal from the community. Current evidence, mainly built on short‐term greenhouse experiments, suggests that Sericea lespedeza (Lespedeza cuneata) invasion not only suppresses native plant species, but also alters soil conditions in host communities. As a result, L. cuneata may create a soil legacy that impedes plant community restoration. We examined the response of a Kansas grassland following L. cuneata removal to determine if historical L. cuneata abundance affected (1) plant community composition and (2) the establishment of additional native species. To address these questions, L. cuneata seeds were sown into 300 plots at a wide range of densities under different combinations of simulated disturbance and soil fertilization. After a three‐year establishment period, L. cuneata was removed from the community, and 13 native forb species were sown into all plots. Over 4 years, we found little evidence for a soil legacy effect that influenced community response post‐removal. Although there was a detectable relationship between community composition and L. cuneata, the variation explained by this relationship was very low. Similarly, the establishment of sown native species was unrelated to the historical abundance of L. cuneata. These results indicate that, regardless of initial density, L. cuneata does not impede plant community recovery in this system if effectively controlled within the first 3 years of invasion, and legacy effects inferred from greenhouse experiments may not translate to impacts on the plant community in the field.

Savannas after afforestation: Assessment of herbaceous community responses to wildfire versus native tree planting

AbstractAfforestation and fire exclusion are pervasive threats to tropical savannas. In Brazil, laws limiting prescribed burning hinder the study of fire in the restoration of Cerrado plant communities. We took advantage of a 2017 wildfire to evaluate the potential for tree cutting and fire to promote the passive restoration of savanna herbaceous plant communities after destruction by exotic tree plantations. We sampled a burned pine plantation (Burned Plantation); a former plantation that was harvested and burned (Harvested & Burned); an unburned former plantation that was harvested, planted with native trees, and treated with herbicide to control invasive grasses (Native Tree Planting); and two old‐growth savannas which served as reference communities. Our results confirm that herbaceous plant communities on post‐afforestation sites are very different from old‐growth savannas. Among post‐afforestation sites, Harvested & Burned herbaceous communities were modestly more similar in composition to old‐growth savannas, had slightly higher richness of savanna plants (3.8 species per 50‐m2), and supported the greatest cover of native herbaceous plants (56%). These positive trends in herbaceous community recovery would be missed in assessments of tree cover: whereas canopy cover in the Harvested & Burned site was 6% (less than typical of savannas of the Cerrado), the Burned Plantation and Native Tree Planting supported 34% and 19% cover, respectively. By focusing on savanna herbaceous plants, these results highlight that tree cutting and fire, not simply tree planting and fire exclusion, should receive greater attention in efforts to restore savannas of the Cerrado.

Suction samplers are a valuable tool to sample arthropod assemblages for conservation translocation

AbstractAn important component of recent nature conservation is the ecological restoration of semi‐natural grasslands. The aim of such projects is usually the restoration of typical plant communities; translocation of animals, by contrast, plays only a minor role. This is based on the assumption that a recovery of the flora will lead to recovered fauna; however, this is not always the case. Suction samplers with gauze collection bags are well suited to sample arthropods, and they may also be helpful for transferring animals. However, to date, the suitability of suction samplers as a translocation tool is unclear due to a lack of empirical data on the mortality rate of the sampled arthropod taxa. In this study, we sampled arthropods (leafhoppers, spiders, beetles, and true bugs) with a suction sampler on 21 calcareous grasslands. Immediately after sampling, animals were stored in collection bags and their mortality rate was determined. We compared storage periods (1, 2, and 3 h) and tested the suitability of a cool box to reduce mortality rates. Our study revealed that arthropod mortality was generally low (9% of all sampled individuals); however, the survival rate was affected by (1) storage time, (2) storage conditions, and (3) arthropod group. The mortality of beetles and true bugs was very low and not influenced by storage time or storage conditions. In contrast, leafhoppers and spiders had higher mortality, which increased with storage time and decreased by the use of a cool box. According to our results, suction samplers can be a valuable tool to sample arthropod assemblages for conservation translocation. In order to reduce mortality in sensitive groups such as leafhoppers and spiders, the storage process can be optimised. We thus recommend (1) using a cool box and (2) minimising the period until release of the collected arthropods at the restored site.

Phosphorus is more effective than nitrogen in restoring plant communities of heavy metals polluted soils

Heavy metal pollution is widespread, and has an increasing trend in some countries and regions. It can be easily accumulated in plants, leading to plant species loss and affecting plant community composition. Artificial restoration can conserve plant diversity in contaminated soils and accelerate the recovery of polluted ecosystems. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can increase the resistance of plants to adversity and promote the growth of plants in heavy metal polluted soils. In order to examine the effect of N and P nutrition on the conservation of plant community, we conducted a comparison experiment in greenhouse using soil with low N and P concentration, and set five treatments: C (soil with no heavy metals and fertilizer addition), H (soil with heavy metals addition but with no fertilizer), HN (soil with heavy metals and N addition), HP treatment(soil with heavy metals and P addition), HNP treatment (soil with heavy metals, N and P addition). Our results showed that heavy metal pollution reduced plant species by 300%, and significantly decreased plant diversity (P < 0.05). N addition increased the richness of plant species and increased the dominance of Euphorbia peplus, but had no significant effect on plant diversity and community structure, while reduced the evenness of plant species. P addition of HP and HNP treatments restored plant species richness and increased plant diversity under heavy metal pollution. The plant community structures of these two treatments were more similar to that of group C. Compared with N addition, P addition had a better performance to restoring the species composition and relative dominance of plant communities. Our results provided a guidance for the restoration of plant communities and the conservation of plant species in low N and P concentration soils with the context of heavy metal pollution.

ECOLOGICAL - PHYSIOLOGICAL CHARACTERISTICS OF FODDER PLANTS USED TO PREVENT DESERTIFICATION IN THE CHUST-PAP ADYRS OF THE FERGHANA VALLEY

Adyrs of Chust-Pap, located in the north-west of the Ferghana Valley of the Republic of Uzbekistan, the process of desertification due to anthropogenic influences has been observed over the past 35-40 years. This process was confirmed by scientists, and evidence was provided. The aim of this study was to analyze the threeyear data on the parameters of the water regime in the conditions of rainfed cultivation of such local plants as Salsola orientalis S. G. Gmel., Kochia prostrata (L) Schrad. subsp. grisea prat. Subsp. nov., Krascheninnikovia ewersmanniana (Stschegl. ex Losinsk.) Grubov., Artemisia sogdiana Bge., used in the restoration of plant communities. A scientific basis has been created for the propagation of species to prevent desertification, that adapted to the region and common in natural ecosystems.

Restoring functionally diverse communities enhances invasion resistance in a freshwater wetland

Abstract Understanding how plant communities reassemble is particularly relevant when invaders are part of the species pool and can compromise restoration or conservation goals. If initial species composition has a lasting impact on community dynamics, it may be possible to enhance biotic resistance to invasion, particularly through diversity effects, by manipulating early community composition. Diversity effects have been investigated much less in wetlands than in uplands. We conducted a large plant community restoration experiment in a freshwater wetland to investigate species and functional diversity effects on biotic resistance to invasion during early community assembly. The wetland was under propagule pressure mostly from Phragmites australis (common reed), but all species not sown in this experiment that established in the plots were treated as ‘invaders’, whether exotic or native. We used a two‐step model selection approach and a diversity‐interaction model framework to test hypotheses about the contribution to invasion success of abiotic conditions, species richness, as well as functional group richness, identity and pairwise interactions, providing a rare test of diversity effects against multiple invaders in wetlands. In all, 20 species invaded the plots. They were grouped for analysis to evaluate the overall resistance of resident communities. The three main invaders, P. australis and two native taxa (Salix spp., Populus deltoides), were also analysed separately. Diversity‐interaction models revealed invader‐specific responses. Functional group identity determined resistance to P. australis, whereas pairwise interactions between functional groups explained resistance to Salix spp. Both effects were retained when grouping all invaders. Resistance to P. deltoides was determined by abiotic conditions. The contribution of specific functional groups varied with invader. Annuals and clonal perennials explained resistance to P. australis, suggesting priority and limiting similarity effects. Interactions, when significant, mostly included fast‐growing annuals. When considering all invaders, identity effects were detected for all functional groups. Synthesis. Diversity effects on invasion resistance vary with invaders in early assembly of restored wetland communities. Restoring functionally diverse communities provides resistance against multiple invaders. Consistent responses between this field experiment and previous pot experiments with the same species suggest that results are robust enough to inform management.

Changes of Characteristics of Soil Contaminated by Oil Products during Electrochemical Cleaning

The article deals with the actual problem of cleaning and remediation of soils contaminated in oil industry. The transmission of a small electric current through polluted soil leads to a decrease of pollutants concentration because of various processes. The paper presents the results of the study of changes in soil characteristics as a result of passing the electric current. Such parameters as the content of chlorides and organic matter of the soil (humus), electrical conductivity, density and soil moisture were studied. The research showed that carrying out low amperage electricity through the soil contaminated with oil and highly mineralized reservoir waters using does not entail critical changes in the soil properties. It was proved that this method can be effectively applied on various soils of oil fields and will not impede the subsequent restoration of plant communities at the treatment site.

Impacts of hydrological restoration on lowland river floodplain plant communities

Many lowland floodplain habitats have been disconnected from their rivers by flood defence banks. Removing or lowering these banks can reinstate regular flooding and thus restore these important wetland plant communities. In this study we analyse changes in wetland hydrology and plant community composition following the lowering of flood defence banks at a floodplain of the River Don in the United Kingdom (UK). The aim of the restoration project was to improve the quality of “floodplain grazing marsh” habitat, which is a group of wetland communities that are of conservation interest in the UK. We analyse changes in species richness and community composition over a period of 6 years, and compare the presence of indicator species from the target floodplain grazing marsh plant communities. The lowering of the flood banks increased the frequency of flood events, from an estimated average of 1.7 floods per year to 571 floods per year. The increased flooding significantly increased the proportion of time that the wetland was submerged, and the heterogeneity in hydrological conditions within the floodplain. There were significant differences in composition between the pre-restoration and restored plant communities. Plants with traits for moisture tolerance became more abundant, although the communities did not contain significantly more ‘target’ floodplain grazing marsh species at the end of the study period than prior to restoration. Colonisation by floodplain grazing marsh species may have been limited because environmental conditions were not yet suitable, or because of a shortage of colonising propagules. While the desired target plant community has not been achieved after 5 years, it is encouraging that the community has changed dynamically as a result of hydrological changes, and that moisture-tolerant species have increased in occurrence. Over the next few decades, the restored flood regime may cause further environmental change or colonisation events, thus helping increase the occurrence of desired floodplain grazing marsh indicator species.

Seed density is as important as limiting similarity, diversity effect, and propagule pressure in plant restoration to control invasion

Restoring invasion-resistant plant communities is critical for the successful control of invasive plant species. It is based on ecological principles, such as limiting similarity, and the diversity–invasibility hypothesis, which can be used to select optimal combinations of species and determine appropriate plant density for the effective suppression of invasion due to propagule pressure. However, no attempt has been made to combine these factors in a single research framework. Here, we show for the first time the relative importance of all significant factors, including seed density, limiting similarity, diversity effect, and propagule pressure, in the invasion mechanism of Sicyos angulatus, an invasive plant species. Our results suggest that seed density, rarely explored in previous studies, is as important a determinant of invasion success as limiting similarity, diversity effect, and propagule pressure. Thus, the density-mediated mechanism must be given careful consideration for the restoration of strong invasion-resistant native plant communities.

Light and warming drive forest understorey community development in different environments.

Plant community composition and functional traits respond to chronic drivers such as climate change and nitrogen (N) deposition. In contrast, pulse disturbances from ecosystem management can additionally change resources and conditions. Community responses to combined environmental changes may further depend on land-use legacies. Disentangling the relative importance of these global change drivers is necessary to improve predictions of future plant communities. We performed a multifactor global change experiment to disentangle drivers of herbaceous plant community trajectories in a temperate deciduous forest. Communities of five species, assembled from a pool of 15 forest herb species with varying ecological strategies, were grown in 384 mesocosms on soils from ancient forest (forested at least since 1850) and postagricultural forest (forested since 1950) collected across Europe. Mesocosms were exposed to two-level full-factorial treatments of warming, light addition (representing changing forest management) and N enrichment. We measured plant height, specific leaf area (SLA) and species cover over the course of three growing seasons. Increasing light availability followed by warming reordered the species towards a taller herb community, with limited effects of N enrichment or the forest land-use history. Two-way interactions between treatments and incorporating intraspecific trait variation (ITV) did not yield additional inference on community height change. Contrastingly, community SLA differed when considering ITV along with species reordering, which highlights ITV's importance for understanding leaf morphology responses to nutrient enrichment in dark conditions. Contrary to our expectations, we found limited evidence of land-use legacies affecting community responses to environmental changes, perhaps because dispersal limitation was removed in the experimental design. These findings can improve predictions of community functional trait responses to global changes by acknowledging ITV, and subtle changes in light availability. Adaptive forest management to impending global change could benefit the restoration and conservation of understorey plant communities by reducing the light availability.

Examples of Understory Plant Communities Observed in Post‐Agricultural Recent Woodlands and Uninterrupted Ancient Forests

We investigated how passive rewilding, a conservation strategy increasingly seen as an emerging tool to counterbalance biodiversity and nature degradation, may spontaneously restore plant communities to a state comparable to ancient forests. Looking beyond species identities, we coupled several taxonomic, functional, and phylogenetic diversity metrics to compare recent and ancient forests. While ancient forests harbored single species compositions, recent woodlands showed a higher phylogenetic richness and distinctiveness and few changes in the functional structure. Our study provides evidence that passive rewilding also promotes the establishment of rich and original understory plant communities, which is important for the conservation of forest biodiversity. Photo credit: Loïs Morel. These photographs illustrate the article “Passive rewilding may (also) restore phylogenetically rich and functionally resilient forest plant communities” by Loïs Morel, Lou Barbe, Vincent Jung, Bernard Clément, Annik Schnitzler and Frédéric Ysnel published in Ecological Applications. https​://doi.org/10.1002/eap.2007

Should I plant or should I sow? Restoration outcomes compared across seven riparian revegetation projects

SummaryTo revegetate native plant communities, it is often cheaper to direct seed than to plant nursery‐grown stock. However, the outcomes of direct seeding can be quite variable, and it is unclear whether direct seeding or planting is more likely to facilitate the restoration of diverse plant communities. To address this question, we compared the outcomes of each method across several recent riparian revegetation projects where both direct seeding and tube‐stock planting were used. We surveyed riparian revegetation projects at seven sites within the greater Melbourne area that had been revegetated between 1 and 4 years previously. Sites were all on land previously used for agriculture or degraded public land and ranged in environmental and climatic conditions. Woody plant density, establishment of target species, species richness, species diversity (evenness) and plant heights were assessed. Direct seeding tended to result in higher plant densities and similar species richness, but lower rates of species establishment and diversity compared with planting. A median of 67% of target species established via direct seeding compared with 100% for planting, with direct seeded areas often dominated by one or two species. In general, overall revegetation outcomes were often driven by climatic and site factors, rather than revegetation method. We suggest that to achieve good restoration outcomes from revegetation in riparian areas, a bet‐hedging or combined approach using both sowing and planting may be the best strategy.