A Global Review of the Woody Invasive Alien Species Mimosa pigra (Giant Sensitive Plant): Its Biology and Management Implications.

SummaryConcerns over the ecological impacts of invasive alien plant species have generated great research interest in understanding the mechanisms that underlie the capacity of such plants to occupy a broad range of habitats. It has been repeatedly suggested that rapid evolution of local adaptation to novel environments may enable invasive plants to occupy a broad range of habitats. However, the classical Darwinian view on evolution by natural selection is that the process is slow and gradual, occurring over thousands of years. Invasive plants typically have a relatively short residence time in their introduced ranges (decades or just a few centuries). Besides the time constraint, founder effects (reduction in population size and genetic diversity) may also limit the capacity of invasive plants to rapidly evolve local adaption. Thus, invasive plants may be less likely than native plants to evolve local adaptation. Interestingly, however, an expanding body of literature documents the existence of local adaptation in invasive plant species within their exotic ranges.Here, we did a phylogenetically controlled meta‐analysis to compare invasive and native plant species for differences in the frequency and magnitude of local adaptation. The meta‐analysis was based on different experiments performed in various habitats including grasslands, steppes, deserts, forests, mountains, wetlands and dunes, and used a total of 134 plant species in 52 families. Forty seven of these species (in 24 families) are alien invaders in the region where the studies were undertaken, while the other 91 species (in 38 families) are native.On average, local plants performed better than foreign plants, and invasive plant species expressed local adaptation just as frequently, and at least as strongly as that exhibited by native plant species. An analysis performed while taking into account different plant life‐history traits showed that self‐incompatible invasive plants exhibited significantly higher frequencies of local adaptation than native plants characterized by the same breeding system.Synthesis. The present results support the suggestion that rapid evolution of local adaptation may enable invasive plant species to occupy a broad range of novel habitats.

Large parts of the Earth are experiencing environmental change caused by alien plant invasions, rising atmospheric concentration of carbon dioxide (CO2 ), and nutrient enrichments. Elevated CO2 and nutrient concentrations can separately favour growth of invasive plants over that of natives but how herbivory may modulate the magnitude and direction of net responses by the two groups of plants to simultaneous CO2 and nutrient enrichments remains unknown. In line with the enemy release hypothesis, invasive plant species should reallocate metabolites from costly anti-herbivore defences into greater growth following escape from intense herbivory in the native range. Therefore, invasive plants should have greater growth than native plants under simultaneous CO2 and nutrient enrichments in the absence of herbivory. To test this prediction, we grew nine congeneric pairs of invasive and native plant species that naturally co-occurred in grasslands in China under two levels each of nutrient enrichment (low-nutrient vs. high-nutrient), herbivory (with herbivory vs. without herbivory) and under ambient (412.9 ± 0.6 ppm) and elevated (790.1 ± 6.2 ppm) levels of CO2 concentrations in open top chambers in a common garden. Elevated CO2 and nutrient enrichment separately increased total plant biomass, while herbivory reduced it regardless of the plant invasive status. High-nutrient treatment caused the plants to allocate a significantly lower proportion of total biomass to roots, while herbivory induced an opposite pattern. Herbivory suppressed total biomass production more strongly in native plants than invasive plants. The plants exhibited significant interspecific and intergeneric variation in their responses to the various treatment combinations. Overall, these results suggest that elevated CO2 and nutrients and herbivory may separately, rather than synergistically, impact productivity of the invasive and co-occurring native plant species in our study system. Moreover, interspecific variation in resource-use strategies was more important than invasive status in determining plant responses to the various treatment combinations.

Invasive foreign species (JAI) are the most serious problem for ecosystems and biodiversity, especially in protected areas. Its fast and aggressive growth makes it easy for it to dominate the land. Tight competition for water, light and nutrients is a serious problem. Therefore, the aim of the research carried out along the Pertamina Complex Patra Asri road, Bandung City, is to determine the diversity of invasive foreign plant species found along the Pertamina road, Patra Asri Complex. The research method was carried out by collecting data directly. Invasive foreign plant species found in the category of spreading to other trees are Mikania micrantha and Ipomoea Cairica. The other types are Mimosa pigra, Imperata cylindrica, Bidens Pilosa L., Paspalum distichum L., and Sesbania drummondii. The impact of invasive plants spreading on other plants will reduce and threaten local growth. Invasive plants can also harm local plants in terms of physiology and morphology as they try to defend and compete for nutrients with invasive plants. Environmental damage due to invasive plants will result in physical damage to the habitat, such as blocking waterways, damaging building structures and disturbing beauty.

Threats and benefits of invasive alien plant species on pollinators

Invasive plants are a major cause of the global biodiversity crisis; it is therefore crucial to understand mechanisms that contribute to their success. South‐western Australia is a global biodiversity hotspot with extremely low soil phosphorus (P) concentrations. In this region, a large proportion of native plant species release carboxylates that mobilise soil P. Many widespread invasive plant species in south‐western Australia are arbuscular mycorrhizal (AM). We hypothesised that some of these invasive AM plant species exhibit similar P‐acquisition strategies as native carboxylate‐releasing P‐mobilising species which allows them to thrive in P‐impoverished soils. To test this hypothesis, we collected 23 common invasive species in the field and assessed their leaf manganese concentration [Mn], relative to that of native reference species at different locations, as a proxy for carboxylate release. In addition, we cultivated seven of the invasive species in hydroponics at different P supply to measure their root carboxylate exudation. Furthermore, we measured leaf P concentration and photosynthetic P‐use efficiency (PPUE) of five invasive species in the glasshouse. In the field investigation, almost all invasive species exhibited significantly higher leaf [Mn] than the negative references, which do not release carboxylates, indicating carboxylate release of the invasive plants. Leaf [Mn] of a few invasives even exceeded that of positive references, which exhibit significant carboxylate release, indicating substantial carboxylate release of these invasives. All glasshouse‐grown invasive species with high field leaf [Mn] released root carboxylates under low P supply. Most of the tested invasive plant species also exhibited greater PPUE than native plants under low P supply. Invasive AM plant species exhibited root exudation of carboxylates as a P‐acquisition strategy, which very likely allows their successful invasion of severely P‐impoverished habitats. Read the free Plain Language Summary for this article on the Journal blog.

Occurrence and damage of invasive alien plants in Dehong Prefecture, western of Yunnan Province

Strong competition from invasive plant species often leads to declines in abundances and may, in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species,suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has involved experiments comparing two conspecific groups of native plants for differences in expression of growth/reproductive traits: populations that have experienced competition from the invasive plant species (i.e. experienced natives) versus populations with no known history of interactions with the invasive plant species (i.e. naıve natives). Here, I employ a meta-analysis to obtain a general pattern of inferred evolutionary responses of native plant species from 53 such studies. In general, the experienced natives had significantly higher growth/reproductive performances than naıve natives, when grown with or without competition from invasive plants.While the current results indicate that certain populations of native plant species could potentially adapt evolutionarily to invasive plant species, the ecological and evolutionary mechanisms that probably underlie such evolutionary responses remain unexplored and should be the focus of future studies.

ABSTRACTPlant invasions have been attracting increasing attention from ecologists because of their worldwide environmental impacts and huge economic costs. Research on the characteristics of the recipient regions is essential for understanding the process of plant invasion. However, few previous studies on invasibility of habitats include social factors, although human activities are critical in the process of plant invasion. China is a vast country with high plant species diversity and a long history of introduction of exotic plant species and is particularly vulnerable to invasive plant species. Alien plant species are widespread in the country. Therefore, the study of invasive plants in China is urgent in practice and theoretically important for developing invasion ecology. For the present study, 126 species were selected to represent the major invasive plant species in China. We then collected data on their species richness in 31 provincial administrative units of China and performed Spearman rank correlations between species richness and possible natural and socio‐economic factors. We found that socio‐economic factors, such as human density and GDP, correlated positively with the species richness of invasive plants in China. In conjunction with the natural and socio‐economic correlations in the study of regional distribution pattern of the major invasive plants, we discussed the factors influencing the regional distribution pattern of the major invasive plants in China. We suggest that native plant species richness was mainly determined by the natural conditions of the regions, while invasive species richness was influenced by natural conditions and human disturbance together.

Plant-soil feedback is recognized as the mutual interaction between plants and soil microorganisms, but its role on the biological invasion of the Brazilian tropical seasonal dry forest by invasive plants still remains unclear. Here, we analyzed and compared the arbuscular mycorrhizal fungi (AMF) communities and soil characteristics from the root zone of invasive and native plants, and tested how these AMF communities affect the development of four invasive plant species (Cryptostegia madagascariensis, Parkinsonia aculeata, Prosopis juliflora, and Sesbania virgata). Our field sampling revealed that AMF diversity and frequency of the Order Diversisporales were positively correlated with the root zone of the native plants, whereas AMF dominance and frequency of the Order Glomerales were positively correlated with the root zone of invasive plants. We grew the invasive plants in soil inoculated with AMF species from the root zone of invasive (I changed) and native (I unaltered) plant species. We also performed a third treatment with sterilized soil inoculum (control). We examined the effects of these three AMF inoculums on plant dry biomass, root colonization, plant phosphorous concentration, and plant responsiveness to mycorrhizas. We found that I unaltered and I changed promoted the growth of all invasive plants and led to a higher plant dry biomass, mycorrhizal colonization, and P uptake than control, but I changed showed better results on these variables than I unaltered. For plant responsiveness to mycorrhizas and fungal inoculum effect on plant P concentration, we found positive feedback between changed-AMF community (I changed) and three of the studied invasive plants: C. madagascariensis, P. aculeata, and S. virgata.

Invasive plant species can hinder the establishment and growth of native plants and impact several ecosystem properties, such as soil cover, nutrient cycling, fire regimes and hydrology. Controlling invasive plants is then a necessary, yet usually expensive, step towards the restoration of an ecosystem. A synthesis of literature is needed to understand variation in invasive plants' impacts and their practical control in restoration contexts, and to identify associated knowledge gaps. We reviewed 372 articles published from 2000 to 2019 covering the control of undesirable plants (both exotic invasive and overabundant native plant species) in ecological restoration to gather information on the main plants being controlled and methods used, and considering the distribution of studies among biomes and countries grouped according to the Human Development Index (HDI). Grasses and forbs were the most‐studied invasive plant species in restoration sites, but invasive trees were well studied in the tropics. Poaceae and Asteraceae were the most studied families of invasive plants. Non‐chemical interventions (mostly mowing and prescribed fire) were used in more than half of the reviewed studies globally, but chemical methods (mainly glyphosate spraying, used in 40% of projects using herbicides) are also common. The reviewed studies were mostly performed in countries with very high HDI. Countries with low and medium HDI used only non‐chemical methods. Synthesis and applications. Decisions about which control method to use depend heavily on the invasive plant species' growth forms, the local economic situation where the restoration sites are located and resources available for control. More developed countries tend to use more chemical control, whereas less developed ones use mainly non‐chemical methods. Since most of the reviewed studies were performed in countries with very high HDI, we lack information from developing countries, which concentrates global hotspots for biodiversity conservation and global commitments of forest and landscape restoration.

Implications of climate change for biocontrol efficacy across the northern range of the invasive plant Linaria dalmatica

South Asia is home to an immense diversity of flora and fauna, which makes it one of the global biodiversity hotspots. Plant invasions are one of several factors that threaten South-Asian biodiversity. This review lists problematic invasive plant species, analyses their negative impacts, and summarises management methods implemented in South Asia using data obtained from research articles and relevant databases (CABI, GISD, GloNAF). The data was used to evaluate the research trends over time, knowledge of the impacts of invasive plants, and management measures aimed at the invasive species. In total, 392 currently invasive vascular plant species were recorded in South Asia. Of these, 41 species are widely distributed in South Asia, occurring in at least three countries, and 20 species that are listed as invasive in South-Asian countries by the book Invasive Plant Species of the World are considered as the most problematic. For a subset of the most problematic species where such information is available, we present management measures that are in place in individual countries. The number of studies on invasive species in South Asia has been increasing, with more than half (53%) represented by local and regional inventories. Among the countries in South Asia, India has the highest number of invasive (145) and naturalized plant species (471). However, the percentage contribution of invasive and naturalized species to the native flora is the highest in the Maldives Islands. Studies on impacts are limited to those on native plants and agriculture; there is a lack of research on impacts on ecosystems and hydrology, as well as on economic costs and human health. Moreover, impacts have been quantified for very few species. Currently, the management of invasive plants is mostly done by physical or mechanical methods; research into opportunities for biological control is inadequate. Our review highlights the urgent need to quantify the impacts of all prevalent and problematic invasive species in South Asia as a crucial step in allocating resources for their management and addressing the knowledge gap in this region.

Invasive plants are known to cause biodiversity loss and pose a major risk to human health and environment. Identification of invasive plants and distinguishing them from native species has been relied on morphological examination. Stringent requirement of floral characters and decreasing number of expert taxonomists are making conventional morphology-based identification system tedious and resource-intensive. DNA barcoding may help in quick identification of invasive species if distinct sequence divergence pattern at various taxonomic levels is observed. The present work evaluates the utility of four molecular markers; rbcL, matK, their combination (rbcL + matK), and psbA-trnH for identification of 37 invasive plant species from India and also in distinguishing them from 97 native species. A psbA-trnH locus was found to be of restricted utility in this work as it was represented by the members of a single family. A hierarchical increase in K2P mean divergence across different taxonomic levels was found to be the maximum for matK alone followed by rbcL + matK and rbcL alone, respectively. NJ clustering analysis, however, confirmed the suitability of combined locus (rbcL + matK) over individual rbcL and matK as the DNA barcode. RbcL showed the lowest resolution power among the three markers studied. MatK exhibited much better performance compared to rbcL alone in identifying most of the species accurately although it failed to show monophyly of genus Dinebra. Two families; Asteraceae and Poaceae, remained polyphyletic in the trees constructed by all three markers. Combined locus (rbcL + matK) was found to be the most suitable marker as it raised the resolution power of both the markers and could identify more than 90% of genera correctly. Phylogenetic tree constructed by Maximum-Parsimony method using combined locus as a molecular marker exhibited the best resolution, thus, supporting the significance of two-locus combination of rbcL + matK for barcoding invasive plant species from India. Present study contributes to the global barcode data of invasive plant species by adding fifty-one new sequences to it. Effective barcoding of additional number of native as well as invasive plant species from India is possible using this dual locus if it is combined with one or more new molecular plastid markers. Expansion of barcode database with a focus on barcode performance optimisation to improve discrimination ability at species level can be undertaken in future.

Part of the challenge in dealing with invasive plant species is that they seldom represent a uniform, static entity. Often, an accurate understanding of the history of plant introduction and knowledge of the real levels of genetic diversity present in species and populations of importance is lacking. Currently, the role of genetic diversity in promoting the successful establishment of invasive plants is not well defined. Genetic profiling of invasive plants should enhance our understanding of the dynamics of colonization in the invaded range. Recent advances in DNA sequencing technology have greatly facilitated the rapid and complete assessment of plant population genetics. Here, we apply our current understanding of the genetics and ecophysiology of plant invasions to recent work on Australian plant invaders from the Cucurbitaceae and Boraginaceae. The Cucurbitaceae study showed that both prickly paddy melon (Cucumis myriocarpus) and camel melon (Citrullus lanatus) were represented by only a single genotype in Australia, implying that each was probably introduced as a single introduction event. In contrast, a third invasive melon, Citrullus colocynthis, possessed a moderate level of genetic diversity in Australia and was potentially introduced to the continent at least twice. The Boraginaceae study demonstrated the value of comparing two similar congeneric species; one, Echium plantagineum, is highly invasive and genetically diverse, whereas the other, Echium vulgare, exhibits less genetic diversity and occupies a more limited ecological niche. Sequence analysis provided precise identification of invasive plant species, as well as information on genetic diversity and phylogeographic history. Improved sequencing technologies will continue to allow greater resolution of genetic relationships among invasive plant populations, thereby potentially improving our ability to predict the impact of these relationships upon future spread and better manage invaders possessing potentially diverse biotypes and exhibiting diverse breeding systems, life histories and invasion histories.

Expansion risk of invasive plants in regions of high plant diversity: A global assessment using 36 species