The pioneer effect advantage in plant invasions: site priming of native grasslands by invasive grasses

AbstractStudies on plant invasions depend on local and regional checklists of the alien flora. However, global overview studies have shown that some regions, including many African countries, remain understudied in this regard. To contribute to filling this gap, here we present the first checklist of alien plants of Sudan and South Sudan (the Sudans). We analysed the taxonomic and geographical composition of the species on this list. Our result show that of the 113 alien species in Sudans (99 in Sudan and 59 in South Sudan), 92 (81.4%) are naturalized and 21 (18.6%) are just casual aliens. The number of naturalized species represent 2.2% of the total flora of the Sudans (4096). The alien species belong to 44 families and 85 genera, and many of them are native to Southern America and Northern America (85.8%). Annual and perennial herbs are the prevailing life forms in the alien flora of the Sudans (68.1%), and, among the casual species, perennial herbs are underrepresented whereas woody tree species are over-represented. Alien plants of the Sudans are mostly used for medicinal and environmental purposes globally. The naturalized plants predominantly occur in man-made disturbed habitats, such as agricultural and ruderal habitats. This first overview of the alien flora of the Sudans should stimulate further research and recording of the alien flora to better understand the drivers and consequences of alien plants in the Sudans.

Download Full-text

Facilitation promotes plant invasions and indirect negative interactions

Oikos ◽

10.1111/oik.08443 ◽

2021 ◽

Author(s):

Christopher J. Lortie ◽

Alessandro Filazzola ◽

Charlotte Brown ◽

Jacob Lucero ◽

Mario Zuliani ◽

...

Keyword(s):

Plant Invasions ◽

Negative Interactions

Download Full-text

Impacts of plant invasions in native plant‐pollinator networks

New Phytologist ◽

10.1111/nph.17339 ◽

2021 ◽

Author(s):

Víctor Parra‐Tabla ◽

Gerardo Arceo‐Gómez

Keyword(s):

Plant Invasions ◽

Native Plant ◽

Plant Pollinator

Download Full-text

The role of host promiscuity in the invasion process of a seaweed holobiont

The ISME Journal ◽

10.1038/s41396-020-00878-7 ◽

2021 ◽

Author(s):

Guido Bonthond ◽

Till Bayer ◽

Stacy A. Krueger-Hadfield ◽

Nadja Stärck ◽

Gaoge Wang ◽

...

Keyword(s):

Microbial Communities ◽

Beta Diversity ◽

Common Garden ◽

Plant Invasions ◽

Invasion Process ◽

Microbial Succession ◽

Invasive Seaweed ◽

Native Populations ◽

Important Trait ◽

Different Populations

AbstractInvasive species are co-introduced with microbiota from their native range and also interact with microbiota found in the novel environment to which they are introduced. Host flexibility toward microbiota, or host promiscuity, is an important trait underlying terrestrial plant invasions. To test whether host promiscuity may be important in macroalgal invasions, we experimentally simulated an invasion in a common garden setting, using the widespread invasive macroalga Agarophyton vermiculophyllum as a model invasive seaweed holobiont. After disturbing the microbiota of individuals from native and non-native populations with antibiotics, we monitored the microbial succession trajectories in the presence of a new source of microbes. Microbial communities were strongly impacted by the treatment and changed compositionally and in terms of diversity but recovered functionally by the end of the experiment in most respects. Beta-diversity in disturbed holobionts strongly decreased, indicating that different populations configure more similar –or more common– microbial communities when exposed to the same conditions. This decline in beta-diversity occurred not only more rapidly, but was also more pronounced in non-native populations, while individuals from native populations retained communities more similar to those observed in the field. This study demonstrates that microbial communities of non-native A. vermiculophyllum are more flexibly adjusted to the environment and suggests that an intraspecific increase in host promiscuity has promoted the invasion process of A. vermiculophyllum. This phenomenon may be important among invasive macroalgal holobionts in general.

Download Full-text

Exotic plants accumulate and share herbivores yet dominate communities via rapid growth

Nature Communications ◽

10.1038/s41467-021-23030-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Warwick J. Allen ◽

Lauren P. Waller ◽

Barbara I. P. Barratt ◽

Ian A. Dickie ◽

Jason M. Tylianakis

Keyword(s):

Plant Invasions ◽

Exotic Plants ◽

Apparent Competition ◽

Indirect Interactions ◽

Soil Biota ◽

Exotic Plant Invasion ◽

Plant Soil ◽

Invasion Hypotheses ◽

Plant Herbivore ◽

Invertebrate Herbivores

AbstractHerbivores may facilitate or impede exotic plant invasion, depending on their direct and indirect interactions with exotic plants relative to co-occurring natives. However, previous studies investigating direct effects have mostly used pairwise native-exotic comparisons with few enemies, reached conflicting conclusions, and largely overlooked indirect interactions such as apparent competition. Here, we ask whether native and exotic plants differ in their interactions with invertebrate herbivores. We manipulate and measure plant-herbivore and plant-soil biota interactions in 160 experimental mesocosm communities to test several invasion hypotheses. We find that compared with natives, exotic plants support higher herbivore diversity and biomass, and experience larger proportional biomass reductions from herbivory, regardless of whether specialist soil biota are present. Yet, exotics consistently dominate community biomass, likely due to their fast growth rates rather than strong potential to exert apparent competition on neighbors. We conclude that polyphagous invertebrate herbivores are unlikely to play significant direct or indirect roles in mediating plant invasions, especially for fast-growing exotic plants.

Download Full-text

The impact of Sosnowsky’s Hogweed on feeding guilds of birds

Journal of Ornithology ◽

10.1007/s10336-021-01898-6 ◽

2021 ◽

Author(s):

Emilia Grzędzicka ◽

Jiří Reif

Keyword(s):

Negative Impact ◽

Bird Community ◽

Plant Invasions ◽

Bird Communities ◽

Feeding Guilds ◽

Guild Structure ◽

Feeding Guild ◽

Potential Impact ◽

Underlying Mechanisms ◽

The Impact

AbstractPlant invasions alter bird community composition worldwide, but the underlying mechanisms still require exploration. The investigation of feeding guild structure of bird communities can be informative in respect to the potential impact of invasion features on the availability of food for birds. For this purpose, we focused on determining the influence of the invasive Sosnowsky’s Hogweed Heracleum sosnowskyi on the abundance of birds from various feeding guilds. In spring and summer 2019, birds were counted three times on 52 pairs of sites (control + Heracleum) in southern Poland, at various stages of Sosnowsky’s Hogweed development (i.e. sprouting, full growth and flowering, all corresponding to respective bird counts). We have shown that the presence of invader negatively affected the abundance of birds from all feeding guilds. However, a closer examination of the invaded sites uncovered that responses of particular guilds differed in respect to development stages expressed by a set of characteristics of the invader. Ground and herb insectivores were more common on plots with a higher number of the invader, while the abundance of bush and tree insectivores was negatively correlated with hogweeds’ height. Granivores were not affected by the invader’s features, while the abundance of omnivores was negatively related to the number of flowering hogweeds. Besides showing the general negative impact of the invader on different feeding guilds, our research has shown that certain aspects of Sosnowsky’s Hogweed invasion may support or depress occurrence of different birds on invaded plots. Knowledge of these aspects may facilitate our capacity for coping with challenges the invasive plants put in front of bird conservationists.

Download Full-text