Search Results (176)

Invasive plant species pose an increasing threat to mangroves globally. This study assessed the impact of Paspalum vaginatum invasion on carbon loss and early recovery following four years of restoration in a mangrove forest with Rhizophora racemosa in Benin. Organic carbon was quantified in the total biomass, including both aboveground and belowground components, as well as in the soil to a depth of −50 cm. In addition, soil gas fluxes of CO₂, CH₄, and N₂O were measured. Three sites were evaluated: a conserved mangrove, a site degraded by P. vaginatum, and the same site post-restoration via hydrological rehabilitation and reforestation. Invasion significantly reduced carbon storage, especially in soil, due to lower biomass, incorporation of low C/N ratio organic residues, and compaction. Restoration recovered 7.8% of the total biomass carbon compared to the conserved mangrove site, although soil organic carbon did not rise significantly in the short term. However, improvements in deep soil C/N ratios (15–30 and 30–50 cm) suggest enhanced soil organic matter recalcitrance linked to R. racemosa reforestation. Soil CO₂ emissions dropped by 60% at the restored site, underscoring restoration’s potential to mitigate early carbon loss. These results highlight the need to control invasive species and suggest that restoration can generate additional social benefits. Full article

Sorghum halepense (L.) Pers. (common name Johnson grass) is a perennial invasive weed that causes great harm worldwide, and its allelopathy has been demonstrated in a series of experiments. The present study offers new insights into its organ-specific phytochemical profiles using state-of-the-art metabolomic technology and explores the effects of a methanol extract of S. halepense rhizomes (ShER) and its major bioactive compounds (p-hydroxybenzoic acid and chlorogenic acid) on three noxious weed species. The phytotoxic effects of ShER are reflected through the inhibition of seed germination and reduced seedling growth, which are accompanied by changes in the antioxidant system of seedlings. Phytotoxicity is species specific and concentration dependent, and it is more pronounced against Chenopodiastrum murale (L.) S. Fuentes, Uotila & Borsch and Datura stramonium L. than highly tolerant Amaranthus retroflexus L. Catalase (CAT) is most likely the major mediator in the removal of reactive oxygen species, which are generated during germination and early seedling growth of Ch. murale exposed to ShER. The results of the present study imply the high potential of ShER in the management of amaranthaceous and solanaceous weeds, such as Ch. murale and D. stramonium, respectively. The present study offers an environmentally friendly solution for the biological control of weeds belonging to the families Amaranthaceae and Solanaceae. Also, the results of this research highlight the possibility of effective management of S. halepense by using it as a feedstock for bioherbicide production. Full article

Garvin Heights Park in southeastern Minnesota, USA, is a 12 ha mosaic of bluff prairie, oak savanna, and oak–hickory woodland co-owned by the City of Winona and Winona State University, with a 40+ year history of encroachment by non-native woody invasives, especially buckthorn (Rhamnus cathartica) and honeysuckles (Lonicera spp.). Habitat restoration was initiated in the early 1990s, but management gaps and a seedbank of invasives compromised initial efforts. More consistent and sustainable restoration activities since 2016 have included cutting and chemical treatment of invasives, managed goat browsing, targeted reseeding and plug planting with native species, and more regular prescribed fires. Throughout the restoration process, we assessed changes in buckthorn densities in response to various management practices, assessed the restored savanna tree community, and documented the presence of blooming plants across all park habitats. Manual clearing of woody invasives and repeated goat browsing significantly reduced buckthorn and honeysuckle abundance in prairies and savannas. Park plant communities responded to the combination of management strategies with reduced densities of woody invasives and expanding diversity (currently >220 species present) of forbs and grasses, including a large and growing population of state-threatened Great Indian Plantain (Arnoglossum reniforme). Prescribed fires have benefitted prairies but have done little to improve savanna plant communities, due largely to excessive tree canopy coverage causing a lack of burnable fuels (i.e., dry forbs and grasses). Improved partnerships between landowners and dedicated volunteers are working to expand restoration efforts to include other portions of the park and adjacent woodlands. Full article

Changes in land use and agricultural practices have altered the resilience of plant communities and can lead to the emergence of invasive species. One of these is the perennial grass species Bothriochloa ischaemum (L.) Kleng., whose diversity-reducing effects are known from several studies. Our exploratory questions were as follows: How does the presence of B. ischaemum affect the diversity and ratio of the species of sandy grasslands? To what extent does this diversity change depend on site characteristics? The supporting studies were carried out in five low-lying sand dune slacks and six relatively higher areas in the upper-intermediate part of the dunes and on an abandoned old field located in the Hungarian Great Plain in the Carpathian Basin. The cover of vascular plant species was recorded in all sampling sites in twelve 2 by 2 m plots, and the dataset was analysed using agglomerative cluster analyses and a non-parametric Kruskal–Wallis test. Five significantly different groups were identified, separating the vegetation types of the sides of the sand dunes, the vegetation types of the dune slack and the old field, and a Stipa borysthenica Kolkov ex Prokudin-dominated vegetation type. Our results suggest that B. ischaemum is only present as small tussocks on the drier, more exposed sides of dunes, with 3.9–24.2% average coverage; is less able to outcompete Festuca vaginata Waldst. et Kit. ex Willd. and S. borysthenica; and is only able to form large tussocks mainly in the lower dune slacks, with 45.6–79.5% average coverage. Here, in the wetter areas, it achieves high cover with a considerable accumulation of litter, and it becomes a dominant species in this association. The diversity-reducing effect of B. ischaemum on old-field grasslands depends on the age of the site and on the stability of the vegetation. Full article

Industrial munition facilities are increasingly manufacturing insensitive high explosives (IHEs) to improve safety. The explosive residues in wastewater from these facilities are treated to meet regulatory standards. However, the resulting effluent contains elevated levels of mineralized nitrogen species. This study evaluated the potential of vetiver grass (Chrysopogon zizanioides), a non-invasive perennial species, to remove high concentrations of nitrate, nitrite, and ammonium from munition plant wastewater. Vetiver was grown hydroponically in synthetic wastewater containing high levels of nitrogen compounds simulating munitions plant effluents. Vetiver plants were treated with one nitrogen species at a time, with concentrations ranging from 165 to 24,700 mg N/L of nitrate, 100 to 4000 mg N/L of nitrite, and 260 to 39,000 mg N/L of ammonium. Nitrogen concentrations in the media and plant responses were monitored over time. The results showed significant nitrogen removal at lower concentration ranges. When concentrations exceeded 3800 mg N/L of nitrate, 800 mg N/L of nitrite, and 2600 mg N/L of ammonium, the removal rates declined after 7 days. At higher nitrogen levels, vetiver exhibited stress symptoms such as chlorosis and elevated antioxidant enzyme activity. Our study demonstrates the potential of vetiver grass in treating nitrogen-rich wastewater from the munition industry and provides a baseline for future large-scale studies to optimize the technology. Full article

In Nigeria, Chromolaena odorata poses significant threats to agriculture by disrupting ecosystem structure and function, thereby altering ecosystem services. However, our understanding of its impact, potential uses, and control measures, particularly from the perspective of local communities who interact directly with the plant, presents opportunities for a balanced approach to sustainable management. The aim of this study was to document the knowledge and perceptions of the introduction and spread of C. odorata, its ethnopharmacological applications, and its effects on crops, livestock, and wildlife, as well as discuss control strategies. Using participatory rural appraisal techniques, we administered semi-structured questionnaires to 150 respondents across six villages in Edo State, Nigeria. The findings reveal that C. odorata is a well-recognized invasive species that has been present for several decades and is commonly referred to by its local name, “Awolowo weed”. Although many respondents were unsure of the reasons behind its introduction, most were familiar with its mode of dispersal. A significant proportion of respondents view the weed as a serious threat to agriculture and a major hindrance to human movement by foot to and from their farmlands where C odorata is dominant. However, many also reported its relative ease of management. Interestingly, 92.7% acknowledged the medicinal value of C. odorata, citing its use in treating fever, wounds, and stomach aches, while 84% reported its ability to enhance soil fertility. Most respondents did not perceive the plant as harmful to livestock or wildlife. Though many believe that the plant has continued to spread, 83.8% oppose its complete eradication. Instead, they highlighted Elephant grass (Pennisetum purpureum Schumach) as a more problematic weed that requires immediate intervention. In summary, exploring the local benefits of C. odorata highlights the importance of leveraging local knowledge and practices to develop a robust, integrated approach for its sustainable long-term management. Full article

The sediments remaining after copper flotation (here referred to as to flotation tailings) are generally characterized by nutrient deficiency and heavy metal enrichment, presenting significant obstacles to vegetation establishment and the development of sustainable ecosystems. This research aimed to evaluate the germination and growth performance of eight grass species on these tailings compared to reference conditions. Seed germination was assessed across flotation tailings, sand, and controlled laboratory environments. Initial establishment success was determined by measuring seedling height and root length three weeks after sowing in a glasshouse pot experiment. The findings revealed that Bromus inermis, Bromus catharticus, and Elytrigia elongata were capable of germinating and growing successfully in the challenging substrate, indicating their potential role in sustainable land management. Despite demonstrating excellent germination and seedling growth under test conditions, Bromus tectorum was deemed unsuitable due to its potential for invasive behavior, which could threaten the sustainability of revegetation efforts. Furthermore, species commonly employed for the revegetation of difficult terrains, including Festuca arundinacea, Festuca rubra, and Lolium perenne, proved entirely ineffective for the sustainable treatment of these flotation tailings. Full article

The invasion of exotic plants threatens biodiversity, affecting ecosystem services and ecological processes in native ecosystems. Road construction creates new environments and contributes to the introduction and spread of exotic and invasive plants. This study aimed to evaluate the representation of different functional groups (annual/biannual herbs and grasses, perennial herbs and grasses, shrubs, trees) in the invasion of exotic species within the assemblage on roadside slopes in the Austrocedrus chilensis forest in northwest Andean Patagonia, Argentina. Roadside slopes (RS) and nearby reference areas (RA) were selected, and the cover of native, exotic, and invasive species from the functional groups was evaluated in 1 m² plots using the Braun-Blanquet method. It was found that invasive perennial herbs and grasses predominated on RS, with a cover (19.6 ± 3.0%) higher than that of RA (8.9 ± 1.5%). Agrostis capillaris and Rumex acetosella were the most abundant invasive species. Native shrubs and perennial herbs and grasses were predominant on RS, with Baccharis rhomboidalis and Acaena pinnatifida being the most abundant. This study demonstrates that the roadside slopes of the Austrocedrus chilensis forest harbor invasive exotic species that can invade nearby natural areas. Early detection of these species is important for proper management and control, thus promoting the conservation of biodiversity in forest environments. Full article

The timely and accurate identification of invasive species is a critical first step in recognizing the threats that they present in their new habitats. The accurate identification of an invasive species, however, can prove difficult if that species displays taxonomic complexity in its native range, i.e., it consists of morphologically similar subspecies. Across its native range, the grass Taeniatherum caput-medusae (medusahead) exhibits taxonomic complexity: three subspecies have been recognized. As part of our ongoing research to better understand the invasion of T. caput-medusae in the western United States, the accurate identification of these three subspecies is a requisite first step. Plants from each native population were grown in a greenhouse common garden, harvested at maturity, and measured using five previously described morphological characteristics. Three characteristics, glume length, glume angle, and palea length, were found to be statistically significant, and are diagnostic in differentiating the three subspecies. The results for the two other characteristics were not significantly different, although conical cell prominence was only slightly non-significant (p = 0.0532). Genetic differentiation among native populations of T. caput-medusae was assessed using allozymes as molecular markers. Results of an UPGMA cluster diagram based on allozyme data indicate that subspecies crinitum is genetically differentiated from the other two, some populations of subspecies caput-medusae and asperum co-occur within a cluster, and subspecies asperum is the most variable. Results of the analysis of multilocus genotypes are generally consistent with the UPGMA diagram (e.g., subspecies caput-medusae and asperum share six multilocus genotypes). Our findings confirm the need for a better understanding of the taxonomic complexity that can be found within the native ranges of invasive species. Full article

Accurate assessment of forage quality is essential for ensuring optimal animal nutrition. Key parameters, such as Leaf Area Index (LAI) and grass coverage, are indicators that provide valuable insights into forage health and productivity. Accurate measurement is essential to ensure that livestock obtain the proper nutrition during various phases of plant growth. This study evaluated machine learning (ML) methods for non-invasive assessment of grassland development using RGB imagery, focusing on ryegrass and Timothy (Lolium perenne L. and Phleum pratense L.). ML models were implemented to segment and quantify coverage of live plants, dead material, and bare soil at three pasture growth stages (leaf development, tillering, and beginning of flowering). Unsupervised and supervised ML models, including a hybrid approach combining Gaussian Mixture Model (GMM) and Nearest Centroid Classifier (NCC), were applied for pixel-wise segmentation and classification. The best results were achieved in the tillering stage, with R² values from 0.72 to 0.97 for Timothy (α = 0.05). For ryegrass, the RGB-based pixel-wise model performed best, particularly during leaf development, with R² reaching 0.97. However, all models struggled during the beginning of flowering, particularly with dead grass and bare soil coverage. Full article

This paper aims to solve the problem of erosion sediment that negatively affects the quality of fallowed soil through the development of a new type of agricultural machinery. The transported erosion sediment will be quantified locally to evaluate the danger of these negative effects on the fallowed soil and on the functionality of the grass cover. Subsequently, a new type of machinery will be proposed for the remediation of eroded sediment and conservation of the fallowed soil. In various fallow research areas with different management methods (such as biobelts, grassed valleys, and grassed waterways), agricultural land affected by eroded sediment was examined, and appropriate machinery was designed to rehabilitate the stands after erosion events. By identifying the physical and mechanical properties of the soil, as well as the eroded and deposited sediment/colluvium, the shape, material, attachment method, and assembly of the working tool for the relevant mobile energy device were designed. The developed tool, based on a plow–carry system using a tractor, features flexible tools that separate the eroded sediment from the fallow land surface, transfer it over a short distance, and accumulate it in a designated area to facilitate subsequent removal with minimal damage to the herbaceous vegetation. The calculated erosion event was 196.9 m³ (179.0 m³ ha⁻¹), corresponding to 295 tons (268.5 t ha⁻¹) deposited from the area of 90 ha. Afterward, the proposed machinery was evaluated for the cost of the removal of the eroded sediment. Based on experience from the field, we calculated that 174 m³ per engine hour results in EUR 0.22 m⁻³. From the performed experiment, it is evident that the proposed machinery offers a suitable solution for eroded sediment removal locally, which prevents further erosion and subsequent sediment deposition in water bodies where the costs for sediment removal are higher. Moreover, we have proven the potential negative impact of invasive plant species because their seeds were stored in the sediment. Finally, it is credible to state that the proposed agricultural machinery offers an effective solution for the eroded sediment relocation, which subsequently can be used for other purposes and monetized. This results in an increase in the profitability of the erosion sediment removal process, which is already in place at the source before further transportation to aquatic systems where the costs for removal are significantly higher. Full article

Background: Aegilops tauschii, a winter annual grass weed native to Eastern Europe and Western Asia, has become a widespread invasive species in the wheat-growing regions of China due to its high environmental adaptability. This study aims to explore the molecular mechanisms underlying the stress resistance of Tausch’s goatgrass, focusing on the HSP70 gene family. Methods: A genome-wide analysis was conducted to identify and characterize the HSP70 gene family in A. tauschii. Afterward, their physicochemical properties, phylogenetic relationships, gene structures, and chromosomal distributions were analyzed. Additionally, cis-acting regulatory elements were predicted to understand their potential role in stress resistance. Results: A total of 19 identified HSP70 family genes were classified into four subfamilies and distributed across all chromosomes. The syntenic analysis revealed extensive homology between Tausch’s goatgrass and wheat HSP70 genes. Segmental duplication was found to play a crucial role in the expansion of the HSP70 gene family. The prediction of cis-acting elements suggested that these genes are involved in stress resistance to various environmental conditions. Conclusions: This study provides a comprehensive overview of the HSP70 gene family in A. tauschii, offering insights into their role in stress resistance and their potential application in understanding invasive species behavior and improving wheat resilience. Further research is needed to validate their functional roles in stress adaptation. Full article

Lake Winona is a 129-hectare urban lake which occupies part of an old side channel of the Mississippi River and has been modified significantly over the past 125 years. The entire shoreline (>8 km) is publicly owned, with current shorelines created mostly during two periods of lake dredging and filling of fringe wetlands 70 and 110 years ago, respectively. Since then, some sections were allowed to revegetate naturally with trees and shrubs, some were armored with riprap, and others have been maintained mostly as turfgrass parklands. Shoreline vegetation assessments and tree stand surveys were completed prior to beginning targeted shoreline rehabilitation in 2017. These rehabilitation activities (encompassing the majority of shoreline) include the following: (1) repeated removal and chemical treatment of woody invasive shrubs/trees (primarily common buckthorn Rhamnus cathartica and nonnative bush honeysuckles Lonicera spp.) by contractors and volunteers; (2) chemical spraying and hand pulling of nonnative invasive ornamental grasses (Miscanthus spp.) and forbs (Japanese hops Humulus japonica; leafy spurge Euphorbia esula) annually or as needed; (3) killing of turfgrass and overseeding with native prairie species; (4) shrub and sapling plantings and overseeding with native species in both wooded and turfgrass sections; (5) installation of wave barriers (using cut woody invasives) and planting of emergent aquatic macrophytes; (6) prescribed burns of prairie plantings; (7) establishment of fixed photo reference points to document changes; and (8) altered park mowing practices to maintain a shoreline buffer of vegetation. These ongoing management activities aim to replace more turfgrass with native prairie, plant more shrubs and trees on shorelines, suppress nonnative invasives, and encourage the development of aquatic macrophyte beds to reduce, or eliminate shoreline erosion. Future management activities will continue to emphasize invasive species control, turfgrass conversion to native vegetation, and shoreline erosion reduction. Full article

The concepts of resilience and resistance (R&R) have been used to improve wildland fuel treatment outcomes by identifying parts of the landscape that are more likely to respond well to treatment. This study examined how the economic benefits and costs of fuel treatments in sagebrush (Artemisia spp.) ecosystems varied with the resilience and resistance properties of the treatment site. Generalized ecological models were developed for the economic analysis of fuel treatments that integrated ecological succession, annual grass invasion, pinyon–juniper expansion, and wildfire to simulate ecosystem dynamics over time. The models incorporated resilience and resistance by varying model parameters related to each plant community’s ability to resist annual grass invasion and recover post-disturbance. Simulations produced estimates of the expected (ex ante) benefit–cost ratio for each treatment. The approach also considered the benefits associated with the system remaining in an ecologically favorable condition, allowing us to report a more holistic measure of the net economic benefits of fuel treatments. The results from the simulations indicated fuel treatment was economically efficient in late-successional sagebrush and early-successional juniper in mountain big sagebrush associations. For sagebrush associations where treatment was economically efficient, higher R&R status sites had higher benefit–cost ratios. The results suggested that treatment costs were more determinative of economic efficiency than treatment benefits. Full article

The traditional ecological reclamation measurements and assessments for the grassland areas damaged by open-pit mining often fall short in revealing the dynamics of plant communities affected by environmental filters during reconstruction, making reclamation efforts crucial. The trait-based community framework has been widely applied due to its great potential to predict the restoration process and provide insight into its mechanisms, but how the traits and environmental factors interact to form communities over time is still uncertain. Therefore, to make this process clear, we used the trait-based community framework, defining target species, non-target species, and common grass species, examining how the mix seed sowing and environment (two surface-covering materials applied to mine dump) affect re-vegetation composition, diversity, and functional traits in 14 years. Four treatments were tested: bio-fence surface-covering materials + sowing (BFS), plant-barrier surface-covering materials + sowing (PBS), sowing without any surface-covering materials (SOW), and a control without seeding and covering (CK). Natural grassland sites were regarded as reference (REF). Our findings indicated that the mix seed sowing and the interaction of surface-covering and time were primarily driving the dynamics of the plant community, affecting composition, the value of diversity, coverage, numbers, richness, and functional traits, such as the community-weighted mean (CWM) and functional diversity (FD), which increased and approached the sites REF. There were significant differences between the treatments and CK for the most traits. Although several results in the treatments approached the REF, significant differences still remained in the last observation year. With the sowing and surface-covering treatment, the re-built communities became more resource-acquisitive in terms of the CWM traits; even the value of the specific leaf area (SLA) exceed the REF after 14 years reclamation. We found those communities were dominated by target species that had a higher traits value than the non-target species, while the CK treatment became more resource-conservative over time due to non-target species dominating. The CWM in treatments tended toward reference levels for specific leaf area (SLA), leaf dry matter content (LDMC), and root dry matter content (RDMC), but not for seed mass (SM), thereby indicating that the above- and below-ground productivity of restored sites gradually overcame abiotic (surface-covering) and biotic (sowing) filters and approached target values. The functional diversity (FD) generally increased, with higher multivariate functional dispersion in the treatments containing more target species, suggesting that re-built communities achieve more resistance to invasion and disturbance over time. Hence, the trajectory of species and communities changing highlights the effectiveness of a trait-based approach in identifying better reclamation treatments and candidate species and provides a positive outlook for future re-vegetation community succession. Full article