Invasive Alien Plants Research Articles

Integrating Locals’ Importance-Performance Perception of Adaptation Behaviour into Invasive Alien Plant Species Management Surrounding Nyika National Park, Malawi

Invasive species are a huge concern to environmental management across the world because they threaten ecosystems, habitats, and species biodiversity, with largely permanent consequences. This study investigates the aspects of community capital and community resilience for the management of Invasive Alien Plant Species (IAPS) under importance-performance analysis in communities surrounding Nyika National Park (Mhuju and Ntchenachena) in Malawi. The study used the binary logistic regression model to determine the locals’ management and adaptation behaviours to IAPS. The findings show that although both IAPS management and adaptation were considered highly important, their performance was only rated at a low level, indicating a significant gap between the importance of eight management and adaptation behaviours for IAPS and their actual performance. The results also show that IAPS management strategies such as ‘’promoting community awareness of common IAPS and their impacts on livelihood” and “incorporating IAPS issues into the school curriculum” are useful in nurturing the locals’ management behaviour. Furthermore, we have identified the following characteristics as having a significant influence on the locals’ participation in IAPS impact reduction and adaptation: (1) age, (2) residential area, (3) understanding the IAPS impacts, (4) membership of farmers’ club or Village Natural Resource Management Committee (VNRMC), and (5) discussion of IAPS in farmer club or VNRMC. These findings provide empirical evidence to policy makers for an effective IAPS management strategy.

Invasive Wedelia trilobata Performs Better Than Its Native Congener in Various Forms of Phosphorous in Different Growth Stages.

At present, many hypotheses have been proposed to explain the mechanism of alien plants' successful invasion; the resource fluctuations hypothesis indicates that nutrient availability is a main abiotic factor driving the invasion of alien plants. Higher phosphorus utilization and absorption efficiency might be one of the important reasons for alien plants successful invasion. Wedelia trilobata, one of the notorious invasive weeds in China, possesses a strong ability to continue their development under infertile habitats. In this study, firstly, W. trilobata and its native congener, W. chinensis, were grown in various phosphorus forms to test their absorption efficiency of phosphorus. Secondly, the different responses of W. trilobata and W. chinensis to the insoluble phosphorus in three growth stages (at 30, 60, and 150 days cultivation) were also tested. The results showed that the growth rate, root morphology, and phosphorus absorption efficiency of W. trilobata under various insoluble, organic, or low phosphorus conditions were significantly higher than that of W. chinensis. During the short-term cultivation period (30 d), the growth of W. trilobata under insoluble and low phosphorus treatments had no significant difference, and the growth of W. trilobata in insoluble phosphorus treatment also had no significant effect in long-term cultivation (60 and 150 d). However, the growth of W. chinensis in each period under the conditions of insoluble and low phosphorus was significantly inhibited throughout these three growth stages. Therefore, invasive W. trilobata had a higher phosphorus utilization efficiency than its native congener. This study could explain how invasive W. trilobata performs under nutrient-poor habitats, while also providing favorable evidence for the resource fluctuations hypothesis.

Perceptions of impacts and management of invasive alien plants: a case study from Mirzapur, India

Invasive alien plants (IAPs) have become a serious threat to biodiversity, agriculture and socio-economic development. Several aspects, including the ecological and economic impacts of IAPs have been explored in the recent past, however, perceptions of ecosystem services (ES) and ecosystem disservices (EDS) have not been well studied. IAPs affect the lives of local people both positively (providing ES) and negatively (providing EDS). IAPs in this region have not been studied through the aspects of ES and EDS that integrate the views and perceptions of local communities. Keeping in view this research gap, the present study was conducted in the Mirzapur district (Uttar Pradesh, India) where IAPs are widely distributed. In five sites covering a rural to urban gradient with increasing distance from forest, we randomly selected 100 respondents–20 from each of the five sites for the survey. A semi-structured questionnaire was used to collect respondents’ perceptions on ES and EDS supplied by IAPs in their local habitats. The questionnaire was designed to obtain data on awareness and knowledge, perceptions of ES and EDS, attitudes toward management, and socio-demographic information. Results indicated that 95% of respondents were familiar with at least one of the 12 IAPs identified as being important in the region. Ipomea carnea and Stylosanthes hamata were the most and least frequently cited plants, respectively. Medical use and reduction in soil fertility were most perceived as ES and EDS, respectively. The value of Spearman’s rank correlation coefficient (Spearman’s ρ = 0.487, p > 0.05) indicates a non-significant correlation between ranks of ES and EDS cited by respondents. Older and less educated people were more aware of the impacts of IAPs. Uprooting was the most commonly used management practice to control the invasion of plant species. People’s attitudes toward the management of IAPs seem to indicate that they prefer to eradicate species that have direct harmful effects on human health and biodiversity. This study provides inputs for incorporating people’s perceptions into the control and management of IAPs in the forest region.

Topsoil and Vegetation Dynamics 14 Years after Eucalyptus grandis Removal in Eastern Cape Province of South Africa.

A great deal of effort has been made to clear invasive alien plants in South Africa, yet it remains unclear if the clearing efforts are yielding positive soil and vegetation recovery trajectories. A few short-term studies have been conducted to monitor soil and vegetation recovery after alien plant removal in South Africa, but convincing, long-term monitoring studies are scarce yet needed. We investigated topsoil and vegetation recovery following Eucalyptus grandis removal 14 years ago by Working for Water in Makhanda, Eastern Cape province of South Africa. The detailed topsoil and vegetation surveys were conducted on forty 10 m × 10 m plots that were in paired cleared and natural sites. The results show no significant differences for the measured soil pH, total N, total C, K, Ca, and Na between the cleared and natural sites, an indication that the two sites are becoming similar. Similarly, the gravimetric soil moisture content shows no significant differences between the two sites, although monthly variations are observed. The topsoils in the cleared sites are hydrophobic as compared to those in the natural sites, which are wettable. We observed no significant vegetation diversity differences between the two sites, with native woody species, such as Crassula pellucida and Helichrysum petiolare, frequently occurring in the cleared sites. We recorded low reinvasion by E. grandis and other secondary invaders like Acacia mearnsii and Rubus cuneifolius in the cleared sites. Based on these results, we conclude that 14 years after E. grandis clearing, both topsoil and vegetation recovery are following a positive trajectory towards the natural sites. However, both reinvasion and secondary invasion have the potential to slow down soil and native vegetation recovery. Recommendations such as timeous follow-up clearing and incorporating restoration monitoring in the WfW clearing programme are discussed.

Effects of 13C isotope-labeled allelochemicals on the growth of the invasive plant Alternantheraphiloxeroides

The secondary metabolites of indigenous plants have significant allelopathic inhibitory effects on the growth and development of invasive alien plants. Methyl palmitate (MP) and methyl linolenate (ML) were used as exogenous allelopathic substances. The research investigated the differences of inhibitory effects of MP and ML on the growth of seedlings of Alternantheraphiloxeroides, and calculated their morphological characteristics, biomass, physiological indicators and the response index (RI). The synthetical allelopathic index (SE) of 1 mmol/L MP was the smallest (− 0.26) and the allelopathic inhibition was the strongest; therefore, it was selected as a 13C-labeled allelochemical. The distribution of 1 mmol/L MP in different parts of A.philoxeroides and the correlation between the biomass ratios of roots, stems and leaves and the 13C content were studied by 13C stable isotope tracing experiments. Atom percent excess (APE) between roots, stems and leaves of A.philoxeroides treated with 1 mmol/L MP were significantly different in terms of magnitude, with leaves (0.17%) > roots (0.12%) > stems (0.07%). The root, stem and leaf biomass ratios of invasive weeds had great significant positive correlation with 13C content (p < 0.01, R2 between 0.96 and 0.99). This current research provides a new idea and method for the control of A.philoxeroides, but large-scale popularization remains to be studied.

Exploring the capability of high-resolution satellite data in delineating the potential distribution of common invasive alien plant species in the Tshivhase Tea Estate

Invasive alien plants (IAPs) continue to exert significant impacts on agriculture in many countries, resulting in food insecurity. IAPs reduce agricultural production through competition and parasitism with planted crops. More recently, the IAPs continue to extend their plasticity to tea plantations, especially in tropical and subtropical areas. This study thus aimed at exploring the potential of SPOT 7 and Sentinel 2 satellite data in mapping the occurrence and co-occurrence of three common IAPs Solanum mauritianum, Lantana camara, and Chromolaena odorata in the Tshivhase Tea Estate in Limpopo Province, South Africa. The stepwise logistic regression models were generated for Solanum mauritianum and Lantana camara occurrence as well as the observed and conditional co-occurrence probability of S. mauritianum (P1), L. camara (P2) and C. odorata (P3). From the remote sensing indices, the Brightness Index (BI) was significant in most SPOT 7 stepwise logistic regression models at p<0.05 whereas the blue, red, and near infrared (NIR) bands and standard deviation (STDv) variables were significant at p<0.05 in most of the Sentinel 2 models. The SPOT 7 model performed Sentinel-2 models, thus resulting in the area under the curve (AUC) of 0.96 for the conditional co-occurrence of S. mauritianum (P1) and L. camara (P2). The Sentinel 2 model yielded an AUC of 0.83. The SPOT 7 model performed superior in mapping the conditional co-occurrence of S. mauritianum and L. camara than the Sentinel 2 model. These results suggest that high spatial resolution satellite images like SPOT 7 can delineate the potential distribution of IAPs in the tea plantation and thus assisting in management strategies geared towards IAP’s elimination and control.

Dynamics of the distribution of invasive alien plants (Asteraceae) in China under climate change

Climate change and biological invasions pose significant threats to the conservation of biodiversity and the provision of ecosystem services. With the rapid development of international trade and economy, China has become one of the countries most seriously affected by invasive alien plants (IAPs), especially the Asteraceae IAPs. For this end, we selected occurrence data of 31 Asteraceae IAPs and 33 predictor variables to explore the distribution pattern under current climate using MaxEnt model. Based on future climate data, the changes in distribution dynamics of Asteraceae IAPs were predicted under two time periods (2041–2060 and 2081–2100) and three climate change scenarios (SSP126, SSP245 and SSP585). The results indicated that the potential distribution of IAPs was mainly in the southeast of China under current climate. Climatic variables, including precipitation of coldest quarter (BIO19), temperature annual range (BIO07) and annual precipitation (BIO12) were the main factors affecting the potential distribution. Besides, human footprint (HFP), population (POP) and soil moisture (SM) also had a great contribution for shaping the distribution pattern. With climate change, the potential distribution of IAPs would shift to the northwest and expand. It would also accelerate the expansion of most Asteraceae IAPs in China. The results of our study can help to understand the dynamics change of distributions of Asteraceae IAPs under climate change in advance so that early strategies can be developed to reduce the risk and influence of biological invasions.

Diversity and distribution of invasive alien plant species along elevation gradient in Makawanpur district, central Nepal

Diversity and distribution of invasive alien plant species along elevation gradient in Makawanpur district, central Nepal

Specific alien plant species predominantly deliver nectar sugar and pollen but are not preferentially visited by wild pollinating insects in suburban riparian ecosystems.

The invasion of alien plants has been rapidly proceeding worldwide due to urbanisation. This might be beneficial to wild pollinating insects, since some alien plant species have large flowers and/or long flowering periods, which can increase nectar sugar and pollen availability. To determine the relative contribution of alien plants to floral resource supply and whether resource-rich alien plants, if any, serve as an important food source of pollinating insects, we performed year-round field observations in suburban riverbanks. We quantified the per-unit-area availability of nectar sugar and pollen delivered by alien and native flowering species and counted wild flower visitors (bees and wasps, hoverflies and butterflies) per plant species. The available nectar sugar and pollen per area were predominantly delivered by a few specific alien species, and the relative contribution of other species to floral resource provision was low throughout the period that wild flower visitors were observed. Nonetheless, the resource-rich alien plants were not visited by as many insects as expected based on their contribution to resource provision. Rather, on a yearly basis, these plants received equal or even fewer visits than other flowering species, including resource-poor natives. We show that despite their great contribution to the gross floral resource supply, resource-rich alien plants do not serve as a principal food source for wild pollinating insects, and other plants, especially natives, are still needed to satisfy insect demand. For the conservation of pollinating insects in suburban ecosystems, maintaining floral resource diversity would be more beneficial than having an increase in gross floral resources by allowing the dominance of specific alien plants.

An evaluation of three evapotranspiration models to determine water fluxes over hillslopes encroached by invasive alien plants in Eastern Cape Province, South Africa

Ecosystem services in the South African grassland biome are being impacted by the presence of invasive alien plants (IAPs), particularly from the Australian genus Acacia. IAPs have elevated landscape water use and determining water fluxes is crucial to defining suitable interventions. This study evaluates three models of water flux over IAP-invaded grassland against evapotranspiration (ET) measured by a large-aperture scintillometer (LAS). ET was modelled using an energy balance model (MEDRUSH), a biophysical model (Penman-Monteith-Leuning (PML)) and a remotely sensed product (MOD16), and their results compared with ET measured by the LAS. ETLAS was measured during an abbreviated field campaign in November 2019 over a dense silver wattle (A. dealbata) stand associated with hillslope seeps. Of the three models tested against the LAS campaign, MEDRUSH performed well-enough to be used to model ET over the continuous scientific-grade micro-meteorological record (315 days). We used MEDRUSH to model ET over the invaded hillslope seeps and compared this with the expected ET that would occur over the adjacent, un-invaded grassland. Total ET over the IAP-invaded area was approximately 536 mm (60% of reference ET) as compared with the grassland (202 mm), showing that woody encroachment significantly increases landscape water use. To estimate the local impact of this, we used earth observation to determine the area of woody invasion in a 2 664 km2 regional window. Approximately 10% (274 km2) of this window was invaded by IAPs and, assuming the geographic window was representative of all the areas invaded by wattle, this represents ~ 89 000 ML of water used annually by the IAPs. Removal of wattle, followed by suitable restoration of landscape functionality, would greatly enhance rangeland productivity and water production from hillslope seeps.

Responses of three invasive alien aquatic plant species to climate warming and plant density.

Climate warming may impact plant invasion success directly, as well as indirectly through changes among interactions within plant communities. However, the responses of invasive alien aquatic species to plant density and rising temperatures remain largely unknown. We tested the effects of plant density and neighbour plant identity at different temperatures to better understand the performance of a community of invasive species exposed to climate warming. A microcosm experiment was conducted with three invasive aquatic plants species-Elodea canadensis, Egeria densa and Lagarosiphon major-, at mono and polycultures with low and high plant density, at 16°C, 19°C and 23°C. The results clearly demonstrated that rising temperature influenced, either as a single parameter or as a combined factor, at least one of the measured traits of the three invasive species. Leaf area of E. densa, root number of L. major and growth of E. densa and L. major were influenced by temperature, plant density and neighbour identity. Plant density influenced all traits with the exception of leaf area of E. canadensis and lateral branch production of E. densa. Neighbour identity had no effect on growth rate and leaf area of E. canadensis, on lateral branch and roots production of E. densa and on leaf area of L. major. These findings establish that rising temperature could enhance competition or facilitation among E. canadensis, L. major and E. densa and could cancel the beneficial effects of the presence of a neighbour species; however, the magnitude of this effect was strongly dependent on plant density. Rising temperature due to climate change will likely play a crucial role in interactions between invasive species within plant communities and in the further spread of these invasive aquatic plants.

Genetic differences among Ailanthus altissima collections across and outside Italy by a Citizen science approach and their susceptibility to the candidate mycoherbicide Verticillium dahliae Kleb.

Ailanthus altissima (Mill.) Swingle is considered one of the worst invasive alien plant species (IAPS) in Europe, able to cause several disturbances to ecosystems and economic issues. To date, the control methods applied are often ineffective, restricted or under assessment by the scientific community, as in the case of Verticillium dahliae (a promising biological control agent to counteract this species). Citizen science initiatives aim to involve the public in the research process to generate genuine outcomes and, in the case of invasive species, represent a valuable additional tool in their earlier detection, monitoring and management. Here, seventy-two citizens were recruited to recognize and record A. altissima across and outside Italy, as well as to collect leaf and seed samples to allow professional scientists to perform the molecular characterization of the Italian (and more) gene pool and, subsequently, test the susceptibility of these provenances to V. dahliae. The collected material matched the identification for the 97% of the cases, and included 129 accessions divided in four genetic groups (with a high percentage of variability, as typically observed for other IAPS subjected to frequent movements and the constant supply of new propagules). Verticillium dahliae inoculation of plants from different provenances selected for each genetic group, revealed a very high mortality (≥93%) independently to the origin area. These outcomes confirm the high susceptibility of A. altissima to the fungal pathogen, and lead to speculate that V. dahliae seems to have no limits in counteracting Ailanthus populations, at least at the Italian level.

Biochemical characterization and mycorrhizal fungal community of plant species in the Brazilian seasonal dry forest.

Invasive alien plant species (IAPS) have the ability to change the biochemical properties and the arbuscular mycorrhizal fungal (AMF) community structure in their rhizosphere. Organic acids, microbial activity, and AMF play a key role in the invader's spread and also has interactions with the soil chemical factors. Our aim here was to assess the rhizosphere's biochemical factors, AMF community composition, and soil chemical properties associated with Cryptostegia madagascariensis (IAPS) and Mimosa tenuiflora (endemic plant species) from the Brazilian Seasonal Dry Forest. The highest values of total glomalin (5.87 mg g-1 soil), root colonization (54.5%), oxalic and malic acids (84.21 and 3.01 μmol g-1 , respectively), microbial biomass C (mg kg-1 ), Na+ (0.080 cmolc kg-1 ), Ca2+ (7.04 cmolc kg-1 ), and soil organic carbon (4.59 g kg-1 ) were found in the rhizosphere of C. madagascariensis. We found dissimilarities on AMF community structure considering the studied plant species: (i) Racocetra coralloidea, Dentiscutata heterogama, Dentiscutata cerradensis, Gigaspora decipiens, and AMF's richness were highly correlated with the rhizosphere of M. tenuiflora; and (ii). The rhizosphere of C. madagascariensis was highly correlated with the abundance of Claroideoglomus etunicatum, Rhizoglomus aggregatum, Funneliformis mosseae, and Funneliformis geosporum. The results of our study highlight the importance of considering C. madagascariensis as potential hosts for AMF species from Glomerales, and a potential plant species that increase the bioavailability of exchangeable Na and Ca at semi-arid conditions.

The competition between Bidens pilosa and Setaria viridis alters soil microbial composition and soil ecological function

Bidens pilosa is recognized as one of the major invasive plants in China. Its invasion has been associated with significant losses in agriculture, forestry, husbandry, and biodiversity. Soil ecosystems play an important role in alien plant invasion. Microorganisms within the soil act as intermediaries between plants and soil ecological functions, playing a role in regulating soil enzyme activities and nutrient dynamics. Understanding the interactions between invasive plants, soil microorganisms, and soil ecological processes is vital for managing and mitigating the impacts of invasive species on the environment. In this study, we conducted a systematic analysis focusing on B. pilosa and Setaria viridis, a common native companion plant in the invaded area. To simulate the invasion process of B. pilosa, we constructed homogeneous plots consisting of B. pilosa and S. viridis grown separately as monocultures, as well as in mixtures. The rhizosphere and bulk soils were collected from the alien plant B. pilosa and the native plant S. viridis. In order to focus on the soil ecological functional mechanisms that contribute to the successful invasion of B. pilosa, we analyzed the effects of B. pilosa on the composition of soil microbial communities and soil ecological functions. The results showed that the biomass of B. pilosa increased by 27.51% and that of S. viridis was significantly reduced by 66.56%. The organic matter contents in the bulk and rhizosphere soils of B. pilosa were approximately 1.30 times those in the native plant soils. The TN and NO3– contents in the rhizosphere soil of B. pilosa were 1.30 to 2.71 times those in the native plant soils. The activities of acid phosphatase, alkaline phosphatase, and urease in the rhizosphere soil of B. pilosa were 1.98–2.25 times higher than in the native plant soils. Using high-throughput sequencing of the 16S rRNA gene, we found that B. pilosa altered the composition of the soil microbial community. Specifically, many genera in Actinobacteria and Proteobacteria were enriched in B. pilosa soils. Further correlation analyses verified that these genera had significantly positive relationships with soil nutrients and enzyme activities. Plant biomass, soil pH, and the contents of organic matter, TN, NO3–, TP, AP, TK, and AK were the main factors affecting soil microbial communities. This study showed that the invasion of B. pilosa led to significant alterations in the composition of the soil microbial communities. These changes were closely linked to modifications in plant traits as well as soil physical and chemical properties. Some microbial species related to C, N and P cycling were enriched in the soil invaded by B. pilosa. These findings provide additional support for the hypothesis of soil-microbe feedback in the successful invasion of alien plants. They also offer insights into the ecological mechanism by which soil microbes contribute to the successful invasion of B. pilosa. Overall, our research contributes to a better understanding of the complex interactions between invasive plants, soil microbial communities, and ecosystem dynamics.

Rural peoples’ perception, attitude, and engagement on invasive alien plants in Mount Manunggal, Cebu Island, Philippines

This research examines the perceptions of rural residents of Mount. Manunggal, Cebu Island, Philippines, on the impact of unintentionally introduced invasive alien plants, such as Mikania micrantha, Lantana camara, and Chromolaena odorata, on their livelihoods. Results suggest that their perception of the impact of each species on their livelihood varies based on criteria such as: (1) the length of time invasive alien plants have been established in the forest, and (2) the kind of household. In addition, a household study revealed that forest-adjacent homes have reacted to invasive alien plants as both victims and beneficiaries. Most of the surveyed 77 families are likely to adapt to the invaded environment because they have a history of interacting with invasive alien plants and regard them as wonderful sources of necessities if appropriately involved. In addition, the data demonstrated rural residents are eager to invest in the control and management of invasive alien plants provided the government provides standardized and adequate technical methods and skills. Without government and stakeholder assistance, decreasing the invasion is seen as impossible, and the acceptance of invasive alien plants as part of the rural ecology is foreseen as a predictable result.

Adaptive ecological knowledge among the Ndjuka Maroons of French Guiana; a case study of two ‘invasive species’: Melaleuca quinquenervia and Acacia mangium

BackgroundTo understand how local ecological knowledge changes and adapts, here in the case of the recent introduction of plant species, we report the knowledge and perceptions of the Ndjuka (Maroon) of French Guiana concerning two tree species, Acacia mangium and niaouli (Melaleuca quinquenervia), which are categorized as “invasive alien plants” in the savannas of their territory.MethodsTo this end, semi-structured interviews were conducted between April and July 2022, using a pre-designed questionnaire, plant samples and photographs. The uses, local ecological knowledge, and representations of these species were surveyed among populations of Maroon origin in western French Guiana. All responses to closed questions collected during the field survey were compiled into an Excel spreadsheet in order to perform quantitative analyses, including the calculation of use reports (URs).ResultsIt appears that the local populations have integrated these two plant species, which are named, used and even traded, into their knowledge systems. On the other hand, neither foreignness nor invasiveness seem to be relevant concepts in the perspective of the informants. The usefulness of these plants is the determining factor of their integration into the Ndjuka medicinal flora, thus resulting in the adaptation of their local ecological knowledge.ConclusionIn addition to highlighting the need for the integration of the discourse of local stakeholders into the management of "invasive alien species,” this study also allows us to observe the forms of adaptation that are set in motion by the arrival of a new species, particularly within populations that are themselves the result of recent migrations. Our results furthermore indicate that such adaptations of local ecological knowledge can occur very quickly.

Invasive clonal plants possess greater capacity for division of labor than natives in high patch contrast environments.

Invasion success of clonal plants is closely related to their unique clonal life history, and clonal division of labor is a crucial clonal trait. However, so far, it is unclear whether invasive alien clonal species generally possess a greater capacity for division of labor than native species and whether this pattern is affected by environmental conditions. To test whether patch contrast affects the differences in the capacity for division of labor between invasive alien and native clonal plants, we selected five pairs of exotic invasive and native clonal plant species that are congeneric and co-occurring in China as experimental materials. We grew the clonal fragment pairs of these invasive and native plants under high, low, or no contrast of reciprocal patchiness of light and nutrient, respectively, with ramet connections either severed (division of labor prevented) or kept intact (division of labor allowed). The results showed that connection significantly decreased the proportion of biomass allocated to roots in distal (younger) ramets, whereas it increased in proximal (older) ramets of all studied plants under high -contrast treatments. This clear pattern strongly indicated the occurrence of division of labor. Furthermore, the connection had a more pronounced effect on the pattern of biomass allocation of invasive alien plants, resulting in a greater increase in biomass for invasive alien plants compared to native plants. These findings suggest that the invasive alien plants possess a greater capacity for division of labor, which may confer a competitive advantage to them over natives, thus facilitating their invasion success in some heterogeneous habitats such as forest edges where light and soil nutrients show a high negative correlation.

Field evidence of caddisfly larvae (Trichoptera: Limnephilidae, Leptoceridae) using alien Crassula helmsii (Kirk) Cockayne fragments (Saxifragales: Crassulaceae) in case construction

We present the first field observations of caddisfly (Trichoptera) larvae using an invasive alien aquatic plant, Crassula helmsii (Kirk) Cockayne, in case construction. In samples from invaded ponds across the UK and Belgium, we have recorded the presence of C. helmsii fragments in cases from Limnephilus lunatus Curtis, 1834, Limnephilus marmoratus Curtis, 1834, Limnephilus flavicornis (Fabricius, 1787) (Limnephilidae), Triaenodes bicolor (Curtis, 1834), and Oecetis furva (Rambur, 1842) (Leptoceridae). Fragmentation of C. helmsii in case creation and augmentation may produce vegetative propagules, thus facilitating further dispersal of this invasive macrophyte.

Test of the colonization ability of the invasive alien plant Flaveria bidentis (Asteraceae) in southern China

Test of the colonization ability of the invasive alien plant Flaveria bidentis (Asteraceae) in southern China

Identification of Invasive Aliens Plant Species in Cultivated Area of Kamojang Crater at Ibun District, Bandung Regency, West Java

The Cultivated Area in Kamojang Crater, Ibun District, Bandung Regency is part of a single landscape mountain, adjacent to conservated and protected areas which has high biodiversity. This study aims to identify invasive alien plants species in cultivated areas, adjacent to conservation and protected areas. The method used is a descriptive qualitative study with the sampling line transect in 500 meter radius of four location, namely near Nature Reserves (NR), near Nature Tourism Parks (NTP), agriculture (A) and near Protected Forests (PF), and this study has done up at July until November, 2022. The results showed that in the cultivated area in Kamojang Crater, Ibun District, Bandung Regency found 41 families and 96 species of understorey, with the highest number being from the Asteraceae, Poaceae and Fabaceae. Diversity of understorey was categorized as high (H'=3.428), evenly distributed (E=0.738), high species richness (R=13.503) and no dominant species (C=0.165). Several understorey, namely 8 orders, 10 families, and 29 species were categorized as invasive aliens plant species, with the highest important values index being Ageratina riparia (99,642%), Imperata cylindrica (72,919%), Paspalum notatum (31,155%), Chromolaena odonata (31,074%), Etlingera elatior (27,905%), Ageratum conyzoides (20,179%), Lantana camara (19,029%), Amaranthus hybridus (18,818%), Pennisetum purpureum (15,120%), Mimosa pudica (15,031%), Crassocephalum crepidioides (14,037%), and Axonopus compresus (10,671%).