scholarly journals Responses of native and invasive woody seedlings to combined competition and drought are species-specific

2020 ◽  
Author(s):  
Andrea Bueno ◽  
Karin Pritsch ◽  
Judy Simon

Abstract Woody species invasions are a major threat to native communities with intensified consequences during increased periods of summer drought as predicted for the future. Competition for growth-limiting nitrogen (N) between native and invasive tree species might represent a key mechanism underlying the invasion process, because soil water availability and N acquisition of plants are closely linked. To study whether the traits of invasive species provide an advantage over natives in Central Europe in the competition for N under drought, we conducted a greenhouse experiment. We analysed the responses of three native (i.e., Fagus sylvatica, Quercus robur, and Pinus sylvestris) and two invasive woody species (i.e., Prunus serotina and Robinia pseudoacacia) to competition in terms of their organic and inorganic N acquisition, as well as allocation of N to N pools in the leaves and fine roots. In our study, competition resulted in reduced growth and changes in internal N pools in both native and invasive species mediated by the physiological characteristics of the target species, the competitor, as well as soil water supply. N acquisition, however, was not affected by competition indicating that changes in growth and N pools were rather linked to the remobilization of stored N. Drought led to reduced N acquisition, growth and total soluble protein-N levels, while total soluble amino acid-N levels increased, most likely as osmoprotectants as an adaptation to the reduced water supply. Generally, the consequences of drought were enhanced with competition across all species. Comparing the invasive competitors, P. serotina was a greater threat to the native species than R. pseudoacacia. Furthermore, deciduous and coniferous native species affected the invasives differently, with the species-specific responses being mediated by soil water supply.

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0237894
Author(s):  
Amy E. Kendig ◽  
Vida J. Svahnström ◽  
Ashish Adhikari ◽  
Philip F. Harmon ◽  
S. Luke Flory

Infectious diseases and invasive species can be strong drivers of biological systems that may interact to shift plant community composition. For example, disease can modify resource competition between invasive and native species. Invasive species tend to interact with a diversity of native species, and it is unclear how native species differ in response to disease-mediated competition with invasive species. Here, we quantified the biomass responses of three native North American grass species (Dichanthelium clandestinum, Elymus virginicus, and Eragrostis spectabilis) to disease-mediated competition with the non-native invasive grass Microstegium vimineum. The foliar fungal pathogen Bipolaris gigantea has recently emerged in Microstegium populations, causing a leaf spot disease that reduces Microstegium biomass and seed production. In a greenhouse experiment, we examined the effects of B. gigantea inoculation on two components of competitive ability for each native species: growth in the absence of competition and biomass responses to increasing densities of Microstegium. Bipolaris gigantea inoculation affected each of the three native species in unique ways, by increasing (Dichanthelium), decreasing (Elymus), or not changing (Eragrostis) their growth in the absence of competition relative to mock inoculation. Bipolaris gigantea inoculation did not, however, affect Microstegium biomass or mediate the effect of Microstegium density on native plant biomass. Thus, B. gigantea had species-specific effects on native plant competition with Microstegium through species-specific biomass responses to B. gigantea inoculation, but not through modified responses to Microstegium density. Our results suggest that disease may uniquely modify competitive interactions between invasive and native plants for different native plant species.


2018 ◽  
Vol 285 (1871) ◽  
pp. 20171936 ◽  
Author(s):  
Tobin D. Northfield ◽  
Susan G. W. Laurance ◽  
Margaret M. Mayfield ◽  
Dean R. Paini ◽  
William E. Snyder ◽  
...  

At local scales, native species can resist invasion by feeding on and competing with would-be invasive species. However, this relationship tends to break down or reverse at larger scales. Here, we consider the role of native species as indirect facilitators of invasion and their potential role in this diversity-driven ‘invasion paradox’. We coin the term ‘native turncoats’ to describe native facilitators of non-native species and identify eight ways they may indirectly facilitate species invasion. Some are commonly documented, while others, such as indirect interactions within competitive communities, are largely undocumented in an invasion context. Therefore, we use models to evaluate the likelihood that these competitive interactions influence invasions. We find that native turncoat effects increase with the number of resources and native species. Furthermore, our findings suggest the existence, abundance and effectiveness of native turncoats in a community could greatly influence invasion success at large scales.


2006 ◽  
Vol 11 (4) ◽  
pp. 429-452 ◽  
Author(s):  
HEIDI J. ALBERS ◽  
MICHAEL J. GOLDBACH ◽  
DANIEL T. KAFFINE

Policies to influence land use decisions in agriculture or grazing can increase the ability of invasive species to out-compete native species and thereby disrupt seemingly stable ecological-economic systems. Building off of models of interdependent resources, invasive species and soil fertility, this paper develops a model of shifting cultivation decisions for two types of farmers, one who sees the threat of invasive grasses and one who does not. The paper uses numerical solutions to this dynamic decision problem to examine the impact of various policies on farmer welfare and on the stability of the economic-ecological system. Some policies undermine the resilience of the system, while other policies augment the system's ability to withstand species invasions.


2012 ◽  
Vol 279 (1742) ◽  
pp. 3436-3442 ◽  
Author(s):  
Michael R. Crossland ◽  
Takashi Haramura ◽  
Angela A. Salim ◽  
Robert J. Capon ◽  
Richard Shine

If invasive species use chemical weapons to suppress the viability of conspecifics, we may be able to exploit those species-specific chemical cues for selective control of the invader. Cane toads ( Rhinella marina ) are spreading through tropical Australia, with negative effects on native species. The tadpoles of cane toads eliminate intraspecific competitors by locating and consuming newly laid eggs. Our laboratory trials show that tadpoles find those eggs by searching for the powerful bufadienolide toxins (especially, bufogenins) that toads use to deter predators. Using those toxins as bait, funnel-traps placed in natural waterbodies achieved near-complete eradication of cane toad tadpoles with minimal collateral damage (because most native (non-target) species are repelled by the toads' toxins). More generally, communication systems that have evolved for intraspecific conflict provide novel opportunities for invasive-species control.


2021 ◽  
Vol 4 ◽  
Author(s):  
Emily Chen

Introduction Aquatic Invasive Species (AIS) are a growing concern for global biodiversity as humans continue to accelerate the transport of non-indigenous species beyond their natural range. These species may possess traits that allow them to thrive in new environmental conditions such as non-selective feeding and high reproductive output, causing ecological harm through competition with native species for limited local resources. Consequently, environmental DNA (eDNA) has come to the forefront of AIS management in recent years as a promising method to detect or monitor invasive species using rapid and non-invasive sampling to complement traditional surveying. As eDNA’s potential is explored and beginning to be adopted for a variety of applications around the world, it is increasingly important to synthesize the trends in field and laboratory protocols from different working groups to establish guidelines that will allow greater comparability between studies and improve experimental design. Methodology and Results This meta-analytic study collated and reviewed information from previously published eDNA studies that targeted AIS in freshwater and marine environments to recognize current patterns in sampling techniques, laboratory protocols, and potential geographic or taxonomic biases. A total of 492 records from 192 full-text articles were used in the analysis, composed of 408 species-specific and 84 metabarcoding records. With regards to sampling procedures, many studies were not explicit enough for true replicability, lacking critical information such as the volume of filtered water and details of storage conditions. There was no observable trend for eDNA extraction methods in either species-specific or metabarcoding approaches, with choice of extraction method being mostly arbitrary among laboratories as well as influenced by the recent emergence of dedicated commercial kits . Discussion This analysis revealed a wide variety of choices for collecting and processing eDNA samples, so it is recommended that there should be some sort of standardized workflow diagram or decision tree for every stage of the experimental design in order for researchers to determine what approaches best meet their research objectives. There is also a clear need for improving metadata reporting guidelines; although the relevance of some criteria depends on the goals and limitations of specific projects, there should be a standardized minimum set of parameters to be reported for each eDNA study, from environmental variables to decontamination practices to PCR conditions. This will increase consistency and transparency through all stages of eDNA research, which is key to collectively improving methodologies and moving forward in this field.


2017 ◽  
Vol 13 (11) ◽  
pp. 20170374
Author(s):  
Lydia Wong ◽  
Tess Nahanni Grainger ◽  
Denon Start ◽  
Benjamin Gilbert

Species interactions are central to our understanding of ecological communities, but may change rapidly with the introduction of invasive species. Invasive species can alter species interactions and community dynamics directly by having larger detrimental effects on some species than others, or indirectly by changing the ways in which native species compete among themselves. We tested the direct and indirect effects of an invasive aphid herbivore on a native aphid species and two host milkweed species. The invasive aphid caused a 10-fold decrease in native aphid populations, and a 30% increase in plant mortality (direct effects). The invasive aphid also increased the strength of interspecific competition between the two native plant hosts (indirect effects). By investigating the role that indirect effects play in shaping species interactions in native communities, our study highlights an understudied component of species invasions.


2023 ◽  
Vol 83 ◽  
Author(s):  
B. Ansari ◽  
J. Altafa ◽  
A. Ramzan ◽  
Z. Ahmed ◽  
S. Khalil ◽  
...  

Abstract Physids belong to Class Gastropoda; belong to Phylum Mollusca and being bioindicators, intermediate hosts of parasites and pests hold a key position in the ecosystem. There are three species of Genus Physa i.e. P. fontinalis, Physa acuta and P. gyrina water bodies of Central Punjab and were characterized on the basis of molecular markers High level of genetic diversity was revealed by polymorphic RAPD, however SSR markers were not amplified. The multivariate analysis revealed polymorphism ranging from 9.09 percent to 50 percent among the three Physid species. Total number of 79 loci were observed for the three species under study and 24 loci were observed to be polymorphic. These RAPD fragment(s) can be developed into co dominant markers (SCAR) by cloning and can be further sequenced for the development of the Physa species specific markers to identify the introduced and native species in Pakistan.


NeoBiota ◽  
2022 ◽  
Vol 71 ◽  
pp. 1-22
Author(s):  
Ming-Chao Liu ◽  
Ting-Fa Dong ◽  
Wei-Wei Feng ◽  
Bo Qu ◽  
De-Liang Kong ◽  
...  

Many studies have attempted to test whether certain leaf traits are associated with invasive plants, resulting in discrepant conclusions that may be due to species-specificity. However, no effort has been made to test for effects of species identity on invasive-native comparisons. Here, we compared 20 leaf traits between 97 pairs of invasive and native plant species in seven disturbed sites along a southwest-to-northeast transect in China using phylogenetically controlled within-study meta-analyses. The invasive relative to the native species on average had significantly higher leaf nutrients concentrations, photosynthetic rates, photosynthetic nutrients- and energy-use efficiencies, leaf litter decomposition rates, and lower payback time and carbon-to-nitrogen ratios. However, these differences disappeared when comparing weakly invasive species with co-occurring natives and when comparing invasives with co-occurring widespread dominant natives. Furthermore, the magnitudes of the differences in some traits decreased or even reversed when a random subset of strongly to moderately invasive species was excluded from the species pool. Removing rare to common natives produced the same effect, while exclusion of weakly to moderately invasives and dominant to common natives enhanced the differences. Our study indicates that the results of invasive-native comparisons are species-specific, providing a possible explanation for discrepant results in previous studies, such that we may be unable to detect general patterns regarding traits promoting exotic plant invasions through multi-species comparisons.


2020 ◽  
Author(s):  
Rosalie Bruel ◽  
J. Ellen Marsden ◽  
Bernie Pientka ◽  
Nick Staats ◽  
Timothy Mihuc ◽  
...  

AbstractInvasive species can have major disruptions on native food webs, yet the impact of species introductions and whether they will become invasive appears to be context-dependent. Rainbow smelt and alewife co-exist as invasive species in the Laurentian Great Lakes and as native species on the Atlantic coast of North America, but in Lake Champlain rainbow smelt is the dominant native forage fish and alewife are invasive. Alewife became abundant by 2007, providing an opportunity to explore the dynamics of these two species in a system where only one is invasive. We used data from a 31-year forage fish survey to compare demographics of rainbow smelt populations in three basins of Lake Champlain with different pelagic volumes, nutrient levels, and predator abundances. Rainbow smelt catch-per-unit-effort (CPUE) remained constant in the large, deep Main Lake before and after alewife invaded, but decreased in the two smaller basins. Declines were primarily a result of increased age-0 and age-1 mortality. Predation by top piscivores, system productivity, and resource competition alone could not explain the patterns in CPUE across the basins. The mechanisms that allow alewife and rainbow smelt to co-exist could be related to system volume and oxythermal habitat availability, and may explain why the two species do not negatively affect each other in other systems. Summer hypoxia in the smaller basins could force individuals into smaller habitat volumes with higher densities of competitors and cannibalistic adult smelt. Our findings suggest that habitat size mediates the impact of invasive alewife on native rainbow smelt.


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