Framework species approach proves robust in restoring forest on fire prone invasive grass : A case study from Panama
Boeschoten, Laura E. ; Breugel, Michiel van; Bailon, Mario ; Balbuena, Johana ; Nuñez, Miguel ; Cerezo, Arturo ; Hall, Jefferson S. - \ 2020
Journal of Sustainable Forestry (2020). - ISSN 1054-9811
Ecosystem rehabilitation - framework species approach - grass elimination - invasive species - reforestation - Saccharum spontaneum
Grasses and fire pose a major challenge for forest restoration. Here we evaluate a case study of reforestation in an area invaded by the tall invasive grass Saccharum spontaneum in the Panama Canal Watershed. The project objectives were to (1) replace Saccharum with a forest, (2) restore a stratified mixed species forest and (3) sequester carbon. We aimed to compare the practice of forest restoration with a treatment grounded in theory. Therefore, the first species selection method followed business-as-usual: contractors planted any combination of 130 prescribed species. The second method followed the framework species approach, a mixture of 22 species was planted to ensure early shade, create a stratified forest over time, attract seed dispersers, and for their potential to fix N2. Both treatments showed successful restoration trajectories 8.5 years after planting, they did not differ in structural characteristics (stem density, basal area, aboveground biomass, height, and amount of Saccharum). However, based on the species present, the framework approach shows more potential to become a stratified forest. As the framework approach also withstood fires much better than the business-as-usual approach, we conclude that it improves restoration success in this human-dominated landscape.
Leidraad beheersing eikenprocessierups uitgebracht: De EPR
Spijker, J.H. - \ 2020
Stadswerk (2020)4. - ISSN 0927-7641 - p. 11 - 13.
invasive species - well-being - health - trees - Quercus robur - ecosystem services
Vorig jaar hebben we ervaren dat de eikenprocessierups onze gezondheid en ons welbevinden aanzienlijk kan schaden. Wat is een effectieve aanpak om de overlast te beheersen zonder onnodig hoge beheerkosten te maken? De ‘Leidraad beheersing eikenprocessierups’ die onlangs werd uitgebracht, geeft antwoorden.
Mixed ancestry from wild and domestic lineages contributes to the rapid expansion of invasive feral swine
Smyser, Timothy J. ; Tabak, Michael A. ; Slootmaker, Chris ; Robeson, Michael S. ; Miller, Ryan S. ; Bosse, Mirte ; Megens, Hendrik Jan ; Groenen, Martien A.M. ; Paiva, Samuel Rezende ; Faria, Danielle Assis de; Blackburn, Harvey D. ; Schmit, Brandon S. ; Piaggio, Antoinette J. - \ 2020
Molecular Ecology 29 (2020)6. - ISSN 0962-1083
admixture - feral swine - invasive species - secondary introductions - Sus scrofa
Invasive alien species are a significant threat to both economic and ecological systems. Identifying the processes that give rise to invasive populations is essential for implementing effective control strategies. We conducted an ancestry analysis of invasive feral swine (Sus scrofa, Linnaeus, 1758), a highly destructive ungulate that is widely distributed throughout the contiguous United States, to describe introduction pathways, sources of newly emergent populations and processes contributing to an ongoing invasion. Comparisons of high-density single nucleotide polymorphism genotypes for 6,566 invasive feral swine to a comprehensive reference set of S. scrofa revealed that the vast majority of feral swine were of mixed ancestry, with dominant genetic associations to Western heritage breeds of domestic pig and European populations of wild boar. Further, the rapid expansion of invasive feral swine over the past 30 years was attributable to secondary introductions from established populations of admixed ancestry as opposed to direct introductions of domestic breeds or wild boar. Spatially widespread genetic associations of invasive feral swine to European wild boar deviated strongly from historical S. scrofa introduction pressure, which was largely restricted to domestic pigs with infrequent, localized wild boar releases. The deviation between historical introduction pressure and contemporary genetic ancestry suggests wild boar-hybridization may contribute to differential fitness in the environment and heightened invasive potential for individuals of admixed domestic pig–wild boar ancestry.
Controlling small hive beetles, Aethina tumida, in western honey bee (Apis mellifera) colonies by trapping wandering beetle larvae
Stief, Karsten ; Cornelissen, Bram ; Ellis, James D. ; Schäfer, Marc O. - \ 2020
Journal of Apicultural Research 59 (2020)4. - ISSN 0021-8839 - p. 539 - 545.
Aethina tumida - biotechnical control - eradication - honey bee pest - invasive species - small hive beetle - wandering larvae trap
The small hive beetle (SHB, Aethina tumida) is an invasive honey bee pest. It has been introduced into many countries worldwide and it will continue to spread. The lifecycle of the SHB is divided between a feeding and reproduction phase inside honey bee colonies and a pupation phase in the soil, surrounding colonies. Once larvae have achieved their ideal weight, they leave the hive in search of suitable soil in which to pupate. Trapping larvae when they leave the hive could reduce the reproductive success of SHBs, as this would break their lifecycle. Therefore, we investigated the larvae containment rate of different trap designs. Dry and wet larvae were released into traps and left to wander for 12 h, after which we counted the larvae remaining in the trap. Similarly, we tested the permeability of different mesh sizes for dry and wet larvae. Finally, we investigated the speed dry larvae are capable of crawling, by recording the time it took them to crawl a known distance. Dry larvae were contained by all traps. While most designs were unable to contain wet larvae, a trap with walls of sandpaper was able to contain all larvae successfully. Larvae could not pass through a mesh size of 1 mm in dry or wet conditions. The mean wandering larvae speed observed was 0.42 cm/sc. We recommend the use of traps for wandering SHB larvae as a mitigative measure for new introductions and a control method for established populations.
Global warming promotes biological invasion of a honey bee pest
Cornelissen, Bram ; Neumann, Peter ; Schweiger, Oliver - \ 2019
Global Change Biology 25 (2019)11. - ISSN 1354-1013 - p. 3642 - 3655.
Aethina tumida - Apis mellifera - biological invasion - climate change - honey bees - invasive species - small hive beetles
Climate change and biological invasions are two major global environmental challenges. Both may interact, e.g. via altered impact and distribution of invasive alien species. Even though invasive species play a key role for compromising the health of honey bees, the impact of climate change on the severity of such species is still unknown. The small hive beetle (SHB, Aethina tumida, Murray) is a parasite of honey bee colonies. It is endemic to sub-Saharan Africa and has established populations on all continents except Antarctica. Since SHBs pupate in soil, pupation performance is governed foremost by two abiotic factors, soil temperature and moisture, which will be affected by climate change. Here, we investigated SHB invasion risk globally under current and future climate scenarios. We modelled survival and development time during pupation (=pupal performance) in response to soil temperature and soil moisture using published and novel experimental data. Presence data on SHB distribution were used for model validation. We then linked the model with global soil data in order to classify areas (resolution: 10 arcmin; i.e. 18.6 km at the equator) as unsuitable, marginal and suitable for SHB pupation performance. Under the current climate, the results show that many areas globally yet uninvaded are actually suitable, suggesting considerable SHB invasion risk. Future scenarios of global warming project a vehement increase in climatic suitability for SHB and corresponding potential for invasion, especially in the temperate regions of the Northern hemisphere, thereby creating demand for enhanced and adapted mitigation and management. Our analysis shows, for the first time, effects of global warming on a honey bee pest and will help areas at risk to prepare adequately. In conclusion, this is a clear case for global warming promoting biological invasion of a pest species with severe potential to harm important pollinator species globally.
Climate change opens new frontiers for marine species in the Arctic: Current trends and future invasion risks
Chan, Farrah T. ; Stanislawczyk, Keara ; Sneekes, A.C. ; Dvoretsky, Alexander ; Gollasch, Stephan ; Minchin, Dan ; David, Matej ; Jelmert, Anders ; Albretsen, Jon ; Bailey, Sarah A. - \ 2019
Global Change Biology 25 (2019)1. - ISSN 1354-1013 - p. 25 - 38.
alien species - aquaculture - climate warming - fisheries - invasion pathways - invasive species - knowledge gap - nonindigenous species - shipping - vessels
Climate change and increased anthropogenic activities are expected to elevate the potential of introducing nonindigenous species (NIS) into the Arctic. Yet, the knowledge base needed to identify gaps and priorities for NIS research and management is limited. Here, we reviewed primary introduction events to each ecoregion of the marine Arctic realm to identify temporal and spatial patterns, likely source regions of NIS, and the putative introduction pathways. We included 54 introduction events representing 34 unique NIS. The rate of NIS discovery ranged from zero to four species per year between 1960 and 2015. The Iceland Shelf had the greatest number of introduction events (n = 14), followed by the Barents Sea (n = 11), and the Norwegian Sea (n = 11). Sixteen of the 54 introduction records had no known origins. The majority of those with known source regions were attributed to the Northeast Atlantic and the Northwest
Pacific, 19 and 14 records, respectively. Some introduction events were attributed
to multiple possible pathways. For these introductions, vessels transferred the greatest number of aquatic NIS (39%) to the Arctic, followed by natural spread (30%) and aquaculture activities (25%). Similar trends were found for introductions attributed to a single pathway. The phyla Arthropoda and Ochrophyta had the highest number of recorded introduction events, with 19 and 12 records, respectively. Recommendations including vector management, horizon scanning, early detection, rapid response, and a pan‐Arctic biodiversity inventory are considered in this paper. Our study provides a comprehensive record of primary introductions of NIS for marine environments in the
circumpolar Arctic and identifies knowledge gaps and opportunities for NIS research and management. Ecosystems worldwide will face dramatic changes in the coming decades due to global change. Our findings contribute to the knowledge base needed to address two aspects of global change—invasive species and climate change.
Data from: Global population divergence and admixture of the brown rat (Rattus norvegicus)
Puckett, Emily E. ; Park, Jane ; Combs, Matthew ; Blum, Michael J. ; Bryant, Juliet E. ; Caccone, Adalgisa ; Costa, Federico ; Deinum, E.E. - \ 2016
commensal - invasive species - population genomics - cityscapes - phylogeography - RAD-seq - Rattus norvegicus - Rattus rattus
Native to China and Mongolia, the brown rat (Rattus norvegicus) now enjoys a worldwide distribution. While black rats and the house mouse tracked the regional development of human agricultural settlements, brown rats did not appear in Europe until the 1500s, suggesting their range expansion was a response to relatively recent increases in global trade. We inferred the global phylogeography of brown rats using 32 k SNPs, and detected 13 evolutionary clusters within five expansion routes. One cluster arose following a southward expansion into Southeast Asia. Three additional clusters arose from two independent eastward expansions: one expansion from Russia to the Aleutian Archipelago, and a second to western North America. Westward expansion resulted in the colonization of Europe from which subsequent rapid colonization of Africa, the Americas and Australasia occurred, and multiple evolutionary clusters were detected. An astonishing degree of fine-grained clustering between and within sampling sites underscored the extent to which urban heterogeneity shaped genetic structure of commensal rodents. Surprisingly, few individuals were recent migrants, suggesting that recruitment into established populations is limited. Understanding the global population structure of R. norvegicus offers novel perspectives on the forces driving the spread of zoonotic disease, and aids in development of rat eradication programmes.
Data from: Distribution of the invasive Caprella mutica Schurin, 1935 and native Caprella linearis (Linnaeus, 1767) on artificial hard substrates in the North Sea: separation by habitat
Coolen, J.W.P. ; Lengkeek, Wouter ; Degraer, Steven ; Kerckhof, Francis ; Kirkwood, R.J. ; Lindeboom, H.J. - \ 2016
Wageningen University & Research
artificial reefs - invasive species - oil & gas platforms - wind farms - shipwrecks - Caprella linearis - Phtisica marina - Pseudoprotella phasma - Caprella tuberculata - Caprella mutica - Caprella equilibra - Caprellidae - holocene
Studying offshore natural and artificial hard substrates in the southern North Sea (51ºN–57ºN/1ºW–9ºE), the invasive introduced Japanese skeleton shrimp Caprella mutica Schurin, 1935 was found to co-exist with the native Caprella linearis (Linnaeus, 1767) only on near-shore locations that had an intertidal zone (e.g., wind farm foundations). In contrast, on far offshore and strictly subtidal locations, such as shipwrecks and rocky reefs, only C. linearis was found. Based on these exploratory observations, we hypothesised that artificial structures that are only subtidal are inhabited exclusively by C. linearis, and never by C. mutica. To test this hypothesis and understand factors driving each species’ habitat preferences, habitat suitability models were constructed using generalised additive models, based on samples collected in 2013–2015 from offshore gas platforms, buoys, shipwrecks, and rocky reefs and combined with data from other published and unpublished surveys (2001–2014). The models showed that the presence of C. mutica is explained by the availability of intertidal and floating hard substrates, suspended particulate matter density (SPM), mean annual sea surface temperature, salinity, and current velocity. The C. linearis model included subtidal hard substrates, SPM, salinity, temperature, and current velocity. The modelled distributions showed a significant difference, demonstrating that C. linearis’ habitat preference does not fully overlap with that of C. mutica. Thus, the native and alien Caprella species are likely to be able to co-exist in the North Sea.
Economic essays on marine invasive species and international fisheries agreements
Walker, A.N. - \ 2016
Wageningen University. Promotor(en): Ekko van Ierland, co-promotor(en): Rolf Groeneveld; Hans-Peter Weikard. - Wageningen : Wageningen University - ISBN 9789462576308 - 165
fisheries - fisheries ecology - agreements - biodiversity - invasive species - europe - marine fisheries - marine fishes - visserij - visserij-ecologie - overeenkomsten - biodiversiteit - invasieve soorten - europa - zeevisserij - zeevissen
This thesis is divided into two parts, as explained in Chapter 1, which focus on different aspects of marine ecological change. Part A considers marine Invasive Alien Species (IAS), which are taxa introduced outside of their native range. The detrimental consequences of invasions for human welfare necessitate management of IAS. There are two types of IAS management. These are (i) management of the risks that an invasion will become established, termed “prevention”, and (ii) management of already established invasions, termed “control”. Chapter 2 considers prevention of invasive species with Ballast Water Management (BWM). Vessels transport invasive species in their ballast water. BWM involves treating ballast water to reduce the risk of successful invasion establishment. Chapter 2 studies the determinants of optimal ballast water treatment standards from a theoretical perspective. Chapter 3 considers control of already established invasions from a spatial and dynamic perspective. We model a non-native habitat divided into patches, where each patch may contain a population of the invasive species, and where spread of the invasion between patches is a stochastic process. In this context, we derive optimal management policies.
The second part of this thesis: Part B, considers International Fisheries Agreements (IFAs). IFAs facilitate cooperation in the management of fish stocks. Cooperation is necessary to ensure sustainable management. Part B focuses on two issues which may affect the stability of cooperation within IFAs. These are; in Chapter 4, changes in stock location, which may occur due to climate change, and in Chapter 5, the risk of stock collapse, which may exist due to overfishing. Part B uses game theory to analyse the effects of these two issues on the stability of the Grand Coalition, which is the state of affairs where all parties cooperate to maximize their joint benefit from the fish stock.
The methods and findings of the thesis are summarized as follows: in Chapter 2 (Part A), we construct a model to study optimal BWM standards. The model is built around the assumption that invasions arriving via ballast water are irreversible, i.e. once an invasion has arrived, it is not possible to reduce the size of the invasive population to zero. The hazard rate of invasion establishment can be reduced by setting a BWM standard. The hazard rate is also affected by the Minimum Viable Population (MVPs) of the species and the possibility of an Allee effect. An MVP exists if there is some population size below which there is an insufficient number of invasive individuals to sustain a population. An Allee effect exists if the probability that a population survives increases at an increasing rate in the size of the population. Our analysis focuses on the conditions under which a BWM standard which aims to reduce invasive populations in ballast water to below their MVPs (as is aimed for by the BWM convention) can be optimal. We find that the current aim of the BWM convention can only be optimal in the case that the hazard function (which determines the hazard rate) is not continuously differentiable around the MVP. We find that Allee effects are a requirement for a continuously differentiable hazard function. Therefore, we find that whether or not an Allee effect exists fundamentally affects whether it is optimal to aim to reduce an invasive population in ballast water to marginally below its MVP.
In Chapter 3 (Part A), we combine aspects of previous modelling approaches to provide new generalized management insights for controlling established invasions. We employ a metapopulation network consisting of patches which are arranged one-dimensionally (i.e. in a line), which is relevant, among other cases, for invasive species spreading along coastlines. We allow for the population size of the invasion within patches to be reduced, which we term “removal”, and we allow for the probability of spread between patches to be reduced without affecting the population sizes directly, which we term “containment”. We employ numerical stochastic dynamic programming to explore how these two interventions (removal and containment) can be optimally applied to minimize the sum of damages from the invasion and the costs of removing and containing the invasion. We find that allowing for varying stock sizes within patches facilitates optimal timing of the application of containment. We also identify two novel optimal policies: the combination of containment and removal to stop spread between patches and the application of up to four distinct policies for a single patch depending on the size of the invasion in that patch.
Chapter 4 (Part B) considers how Grand Coalitions can be stabilized in the face of changing stock location. To do so, we employ the Gordon-Schaefer fisheries model. We consider farsightedness as a mechanism by which stability of the Grand Coalition can be increased in the face of changing stock location. Farsightedness allows players to respond to deviations of other players by deviating themselves. This reduces the incentives to leave the Grand Coalition. This is in contrast to shortsightedness, whereby players cannot decide to leave the Grand Coalition in response to such a choice by another player. We begin by modifying the farsightedness concept such that it can be used in games with asymmetric players and transfer payments. We proceed to analyse the modified farsightedness concept in the case where players are symmetric (stock location does not change) in order to identify the properties of the concept in the base case. We find that farsightedness increases Grand Coalition stability with respect to shortsightedness. We proceed to analyse the extent to which farsightedness increases Grand Coalition stability, relative to shortsightedness, as fish stock location changes, using sensitivity analysis. We find that farsightedness increases the stability of the Grand Coalition, but also increases the sensitivity of stability to changes in fish stock location. Thus, for any fish stock location, a Grand Coalition is more likely to be stable if players are farsighted, but shifts between a stable and an unstable Grand Coalition will occur more frequently if players are farsighted.
In Chapter 5 (Part B), we analyse how the stability of Grand Coalitions is affected by an endogenously determined risk of stock collapse. We do so using the Levhari and Mirman (LM) fisheries model, which is adapted such that there is a risk of stock collapse which increases as the fish stock size decreases. We numerically solve the model and calculate the stability of the Grand Coalition. We find that the effect of an endogenously determined risk of stock collapse depends heavily on the assumptions made regarding how payoffs are determined. A common assumption in the literature is that payoffs are determined at the steady state fish stock. Under this assumption, endogenous risk means that for specific discount and growth rates, a Grand Coalition is stable for any number of players. This is a very different result from the original LM model whereby Grand Coalitions can never be sustained. This is because players can essentially follow two strategies in response to the risk. Firstly, they can attempt to maintain the fish stock by fishing less. In doing so they are running the risk of collapse. Secondly, they can avoid the risk by pre-emptively depleting the fish stock, i.e. harvesting the stock to zero immediately to avoid the risk. Grand Coalitions of any number of players are stable for parameterizations for which a Grand Coalition attempts to maintain a non-zero fish stock and if a deviation from the Grand Coalition would result in pre-emptive depletion. We proceed by relaxing the assumption that payoffs are determined in the steady state by allowing for deviators to obtain payoffs in the transition between steady states. In this case, only Grand Coalitions of two players are stable, and then only for certain parameterizations. The reason is that players can now gain payoffs in the process of pre-emptively depleting the stock, i.e. payoffs are received from the process of fishing the stock down to zero. This increases the benefit of deviating from the Grand Coalition. In this case, Grand Coalitions are only stable for two players for specific parameterizations.
Chapter 6 summarises the research questions formulated in Chapter 1 and evaluates the work of the thesis. Regarding Chapter 2, we justify our theoretical approach with the following two points. Firstly, BWM management is a global and complex problem, which means that the information required to formally calculate an optimal standard is prohibitively burdensome. Secondly, we argue that the complexity of BWM necessitates a sound theoretical understanding of the problem in order to evaluate the current BWM standard, and also to aid in future policy formulation. Similarly, in Chapter 3, we focus on deriving generalized management insights which are applicable to a variety of real-world cases, as opposed to deriving an optimal management strategy for a specific case. In addition to the data requirements necessary to derive such a management strategy, the complexity of such applied cases leads to potentially excessive computational burden. Chapter 3 analyses systems of two and three patches, which are likely to be too simple to analyse specific real world cases, but are sufficient to derive generalized management insights.
The game theoretic methodologies in Part B are evaluated principally in terms of the assumptions about changes in stock location in Chapter 4 and the numerical method in Chapter 5. In Chapter 4, the fish stock is conceptualised as existing at a single point in space. The location of this point is determined in relation to fishing nations, which are also conceptualised as single points in space. Changes in stock location result from rises in ocean temperatures due to climate change. Such rises in temperature are likely to lead to other changes in the fish stock such as the size of the area where the fish stock can be found and increases in the maximum fish stock size which the ecosystem can support. These other aspects of changing stock location need to be considered in evaluating Chapter 4, as well as in formulating more applied models. In Chapter 5, a numerical method is adopted to analyse the effects of an endogenous risk of stock collapse. To do so, the utility function in the LM model is adapted such that it can be used in a numerical model. In order to isolate the effect of endogenous risk from changes in the utility function, a validation procedure is carried out by comparing analytically derived results in the deterministic case (without endogenous risk of stock collapse) to numerically derived results in the deterministic case. This reveals that changes to the utility function have a negligible effect and thus the results, in terms of the stability of Grand Coalitions can be attributed solely to endogenous risk of stock collapse.
Overall, Part A of this thesis presents new insights into the determinants of optimal BWM standards. These insights demonstrate the conditions under which the current BWM standard, which aims to eliminate the risk of invasion establishment, may or may not be optimal. Part A therefore provides a novel theoretical framework which aids in the evaluation of current, and the determination of future standards. Part A also provides new insights into the control of established invasions, by extending existing spatially explicit optimal control models. Specifically, dividing space into patches and allowing for varying invasive population sizes within patches facilitates the optimal timing of management interventions and, in general, more detailed, and thus more efficient, management strategies. Part B provides a novel analysis of the effects of changing stock location on Grand Coalitions by explicitly introducing fish stock location in the analysis, and shows how farsightedness can stabilize Grand Coalitions in the face of such changes. Part B also shows how the effects of an endogenous risk of stock collapse on the stability of Grand Coalitions depends vitally on whether transition payoffs are included. These results can form the basis for more interdisciplinary analyses, analyses of different types of marine ecological change, and analyses of these changes in different settings, such as non-European countries.
Invasieve soorten Waddenzee: : Introductiekansen van probleemsoorten via schelpdiertransport
Tamis, J.E. ; Sneekes, A.C. ; Jak, R.G. - \ 2015
Den Helder : IMARES (Rapport / IMARES C173/15) - 49
invasieve soorten - schaaldieren - veevervoer - verspreiding - aquatische ecosystemen - milieueffect - waddenzee - nederland - invasive species - shellfish - transport of animals - dispersal - aquatic ecosystems - environmental impact - wadden sea - netherlands
Invasieve soorten Waddenzee: : Ecosysteem resistentie en de Filipijnse tapijtschelp
Sneekes, A.C. ; Mendez Merino, Natalia ; Weide, B.E. van der; Glorius, S.T. ; Tamis, J.E. - \ 2015
Den Helder : IMARES (Rapport / IMARES C175/15) - 67
invasieve soorten - schaaldieren - veevervoer - weerstand - aquatische ecosystemen - milieueffect - waddenzee - nederland - invasive species - shellfish - transport of animals - resistance - aquatic ecosystems - environmental impact - wadden sea - netherlands
Patterns of exotic plant species in the Netherlands: a macroecological perspective
Speek, T.A.A. - \ 2015
Wageningen University. Promotor(en): Wim van der Putten, co-promotor(en): Bert Lotz. - Wageningen : Wageningen University - ISBN 9789462572898 - 158
geïntroduceerde soorten - vegetatie - plantengeografie - invasieve soorten - plantengemeenschappen - dominantie - nederland - introduced species - vegetation - phytogeography - invasive species - plant communities - dominance - netherlands
In dit proefschrift heb is onderzocht wat mogelijkheden zijn om het invasief potentieel van geïntroduceerde plantensoorten en de invasibiliteit van plantengemeenschappen in Nederland te voorspellen. Soorten zijn gebruikt die hier al geïntroduceerd zijn, omdat van deze hun invasief succes bekend is. Om hun invasiviteit te kwantificeren is informatie gebruikt over de regionale en lokale verspreiding. De unieke beschikbaarheid van deze datasets voor plantensoorten in Nederland bieden nieuwe kansen, die mogelijk helpen de voorspelbaarheid van invasiviteit te verhogen, uit te leggen hoe invasiviteit van een soort kan veranderen in de tijd en hoe de samenstelling van de plantengemeenschap kan bepalen welke geïntroduceerde soorten zich kunnen vestigen.
Invasieve soorten, column juridica
Kistenkas, F.H. - \ 2015
Vakblad Natuur Bos Landschap 12 (2015)114. - ISSN 1572-7610 - p. 27 - 27.
invasieve soorten - fauna - flora - habitats - eu regelingen - invasive species - fauna - flora - habitats - eu regulations
Nu iedereen bezig is met PAS en onze eigen nationale wetsontwerpen voor nieuwe omgevings- en natuurbeschermingswetten, hoor je niemand over nieuwe Europese groene wetgeving die net in werking is gegaan. Terwijl onze omgevingswet blijft doormodderen in allerlei ontwerpfases en hooguit pas in 2018 in werking treedt, zijn er een paar EU-verordeningen inmiddels wel echt al in werking getreden. Toch hoor je er niks over.
Proximate response of fish, conch, and sea turtles to the presence of the invasive seagrass Halophila stipulacea in Bonaire
Becking, L.E. ; Bussel, T. ; Engel, M.S. ; Christianen, M. ; Debrot, A.O. - \ 2014
Den Helder : IMARES (Report / IMARES Wageningen UR C118/14) - 35
lespedeza stipulacea - invasieve soorten - marien milieu - zeeplanten - bonaire - lespedeza stipulacea - invasive species - marine environment - marine plants - bonaire
In this report we examined the proximate response of fish assemblages, queen conch, and sea turtles on H. stipulacea meadows in Lac Bay, Bonaire, Caribbean Netherlands. Here we primarily focused on the differences between the invasive species H. stipulacea and the principal species of native sea grass in Lac Bay, namely turtle grass Thalassia testudinum.
|Invasion Biology and Ecosystem Theory: Insights from a Continent in Transformation
Prins, H.H.T. ; Gordon, I.J. - \ 2014
Cambridge : Cambridge University Press - ISBN 9781107035812 - 530
invasies - invasieve soorten - ecologie - ecosystemen - planten - dieren - australazië - invasions - invasive species - ecology - ecosystems - plants - animals - australasia
Many conservationists argue that invasive species form one of the most important threats to ecosystems the world over, often spreading quickly through their new environments and jeopardising the conservation of native species. As such, it is important that reliable predictions can be made regarding the effects of new species on particular habitats. This book provides a critical appraisal of ecosystem theory using case studies of biological invasions in Australasia. Each chapter is built around a set of 11 central hypotheses from community ecology, which were mainly developed in North American or European contexts. The authors examine the hypotheses in the light of evidence from their particular species, testing their power in explaining the success or failure of invasion and accepting or rejecting each hypothesis as appropriate. The conclusions have far-reaching consequences for the utility of community ecology, suggesting a rejection of its predictive powers and a positive reappraisal of natural history.
Multitrophic interactions on a range-expanding plant species
Fortuna, T.F.M. - \ 2013
Wageningen University. Promotor(en): Louise Vet; J.A. Harvey. - Wageningen : Wageningen UR - ISBN 9789461737656 - 229
planten - invasieve soorten - geïntroduceerde soorten - herbivoren - ongewervelde dieren - natuurlijke vijanden - predatoren - parasitoïden - multitrofe interacties - bunias orientalis - verdedigingsmechanismen - plants - invasive species - introduced species - herbivores - invertebrates - natural enemies - predators - parasitoids - multitrophic interactions - bunias orientalis - defence mechanisms
Studies on the ecological impacts of exotic invasive plants have mainly focused on inter-continental invasions. However due to global environmental changes, a rapid increase in intra-continental range-expanding plants has been observed. In this context, multitrophic interactions between exotic plants, native herbivores and their natural enemies have been largely ignored. This thesis aimed at examining how an exotic range-expanding plant interacts with aboveground insect herbivores and their natural enemies and how it can contribute to the successful establishment of the exotic plant. In addition, it examines how resistance traits of different populations of the range-expander affect the behaviour and performance of herbivores and their natural enemies in the new habitat. Bunias orientalis (Capparales: Brassicaceae) is perennial plant from extreme south-eastern Europe and Asia that has recently expanded its range and become invasive in northern and central parts of Europe. In the Netherlands, it is considered naturalized but non-invasive.
Firstly, using a community approach, I found that Bu. orientalis suffered less herbivore damage and harboured smaller invertebrate communities than sympatric native Brassicaceae in the Netherlands. The exotic plant has been found of low quality for the larval growth of the specialist herbivore (Pieris brassicae). Furthermore, two of its gregarious parasitoids were differentially affected by the quality of the exotic plant. The pupal parasitoid (Pteromalus puparum) survived better than the larval parasitoid (Cotesia glomerata), and the latter parasitized less hosts on the exotic than on native plants. Therefore, the herbivore can be selected to adapt to the new plant by conferring an enemy free space to the herbivore. In this case, a plant shift by the specialist herbivore might occur and thus preventing the further spread of the exotic plant. Conversely, in the field I found greater carnivore pressure on Bu. orientalis compared to other native Brassicaceae, particularly in the peak of arthropod abundance. Hence, top-down forces exerted by herbivore natural enemies may act in concert with bottom-up control of plant resistance traits to counteract herbivore plant shift and promote the successful range expansion of the exotic plant.
Secondly, using a biogeographical approach, I found a considerable intraspecific variation in defence traits (trichomes, glucosinolates, metabolic fingerprints) of Bu. orientalis populations from the native and the exotic range. Plants collected in the native range were better defended than their exotic conspecifics. This variation matched with the performance of a generalist herbivore (Mamestra brassicae) and its parasitoid (Microplitis mediator), which developed poorly in plants from the native range. The results suggest that the defensive mechanisms of Bu. orientalis might have been counter-selected during the range expansion of the exotic plant. Further studies, however, need to examine if enemy release in the new range is followed by an increase in performance of the exotic plant. Finally, a comparative study of multitrophic interactions, both above- and belowground, in the plant native range and along the transect of its range expansion can help to clarify the mechanisms underlying the invasive success of Bu. orientalis.
Mitigatie van effecten van uitheemse grondels: kansen voor natuurvriendelijke oevers en uitgekiende kunstwerken
Kessel, N. van; Kranenbarg, J. ; Dorenbosch, M. ; Bruin, A. de; Nagelkerke, L.A.J. ; Velde, G. van der; Leuven, R.S.E.W. - \ 2013
Nijmegen : Instituut voor Water en Wetland Research, Radboud Universiteit (Verslagen Milieukunde 436) - 88
invasieve soorten - gobio gobio - fauna - vissen - habitats - oevervegetatie - aquatische ecologie - invasive species - gobio gobio - fauna - fishes - habitats - riparian vegetation - aquatic ecology
Het afgelopen decennium zijn de Nederlandse rivieren in hoog tempo gekoloniseerd door vier Ponto-Kaspische grondelsoorten, namelijk de marmergrondel (Proterorhinus semilunaris), zwartbekgrondel (Neogobius melanostomus), Kesslers grondel (Ponticola kessleri) en Pontische stroomgrondel (Neogobius fluviatilis). Deze uitheemse grondels zijn invasieve vissen met een bodemgebonden levenswijze en kunnen plaatselijk in hoge dichtheden voorkomen. Hoewel de verspreidingpatronen van invasieve grondels in Nederland tot op heden grofweg bekend zijn, bestaat geen duidelijk inzicht in de verspreidingprocessen en dichtheden van de grondels in verschillende watertypen, hun (ecologische) effecten en kansrijke mogelijkheden om ongewenste effecten te beperken.
Nyssen, B. ; Ouden, J. den; Verheyen, K. - \ 2013
Zeist : KNNV - ISBN 9789050114523 - 160
prunus serotina - bosecologie - geïntroduceerde soorten - invasieve soorten - bosbedrijfsvoering - nederland - forest ecology - introduced species - invasive species - forest management - netherlands
Hij is de schrik van veel bosbeheerders: de Amerikaanse vogelkers. Maar het verhaal achter de boom is verrassend. Want zijn positieve eigenschappen wegen wellicht op tegen de nadelen. Dit boek belicht alle kanten en laat zien hoe we deze boom een plek kunnen geven in het Europese bosecosysteem. In dit boek wordt een nieuw perspectief geschetst op de Amerikaanse vogelkers. Zij blijkt in haar oorsprongsgebied een waardevolle boomsoort, en in onze bossen heeft vogelkers uiteindelijk ook gunstige effecten op het bosecosysteem. Bovendien worden lang niet al onze bossen massaal gekoloniseerd. De auteurs pleiten voor een genuanceerdere kijk op de vogelkers, waarbij handvatten worden gegeven voor een gedifferentieerd beheer. Het boek behandelt de introductie en bestrijding en de huidige problematiek rondom deze exoot. Ook haar invloed op bossuccessie, biodiversiteit, houtteelt en beheerstrategieën komen aan de orde. Dit boek laat zien hoe we deze exoot een plek kunnen geven in het Europese bosecosysteem, en tegelijk de bestrijdingskosten kunnen verminderen. Actuele kennis zorgvuldig en toegankelijk bijeengebracht voor specialisten in boomteelt, bosbeheerders, beleidsmakers en ecologen.
Early warning program to manage the introduction and spread of invasive species in the Wadden Sea, a World Heritage protected ecosystem
Sneekes, Andrea - \ 2013
aquatic ecology - invasive species - sampling - dna barcoding - dna - dna sequencing - wadden sea
Reproduction in crabs: strategies, invasiveness and environmental influences thereon
Brink, A.M. van den - \ 2013
Wageningen University. Promotor(en): Han Lindeboom, co-promotor(en): Aad Smaal; C. McLay. - S.l. : s.n. - ISBN 9789461735232 - 164
krabben (schaaldieren) - geslachtelijke voortplanting - geslachtsselectie - groei - voortplantingsvermogen - invasieve soorten - populatiedynamica - omgevingstemperatuur - milieufactoren - mariene ecologie - crabs - sexual reproduction - sexual selection - growth - reproductive performance - invasive species - population dynamics - environmental temperature - environmental factors - marine ecology
This thesis provides insights into the interconnectedness of crab reproductive biology, the selective forces leading to their development, the possible links to invasiveness and the influences of environmental factors thereon. The empirical data collected and presented in this thesis can be used to compare different crab species and make predictions about the effect of climate change on their population dynamics and invasiveness.
Hemigrapsus takanoi is native to the north west Pacific, but has been introduced and is very successful in Europe. The species shows indeterminate growth, hard-shell mating, a defined breeding season and ventral seminal receptacles. With indeterminate growth they continue moulting and growing throughout their adult life. After their pubertal moult, these species can mate throughout the year and produce 2-3 broods between each moult. They are not limited in growth or regeneration of limbs and can safely hide from predators during the vulnerable soft-shell inter-moult period rather than mating which exposes them to predators.
Despite their different reproductive strategies, broods of both species showed a similar reaction to increased water temperature in that the duration of development of the brood decreased as temperature increased. Extrapolating the results to a climate change scenario, it is suggested that with a temperature rise of 2°C H. cookii could produce one extra brood of over 1000 offspring per female life time, potentially leading to a 10-15% increase in fecundity and possible population growth. As H. takanoi does not show continuous brood production, predicting the effect of temperature rise is more difficult, but evidence suggests that fecundity is also likely to increase in this species with an increase in water temperature.
Temperature increase may also lead to a change in invasiveness of a species. If areas currently below the optimum temperature for a species become warmer, it is possible that a species may spread to the new locations. Hemigrapsus takanoi may spread further north in Europe than it’s current distribution (assuming it is limited by temperature). Furthermore, if temperatures increase the rate of reproduction in a non-indigenous species, they may become more invasive in their present location.
The colonisation of a new habitat will involve new interactions, such as predation and competition, with species not previously encountered. The interactions of the two invasive crab species H. takanoi and Hemigrapsus sanguineus with the native Carcinus maenas in the delta waters of SW Netherlands was also investigated in this thesis. Whereas C. maenas was the most common shore crab in these waters, its numbers have declined on the soft sediment substrates during the last 20 years. As the two invasive crab species were first recorded in the Dutch delta in 1999, they could not have initiated the decline of the native C. maenas. However, within a few years H. takanoi completely dominated the intertidal hard substrate environments; the same environments on which juvenile C. maenas depend. On soft sediment substrate the native and invasive crab species are presently more or less equally abundant. Nowadays H. takanoi appears to be a fierce interference competitor or predator for small C. maenas specimens by expelling them from their shelters. However, due to the habitat generalist nature of C. maenas, it is unlikely that the Hemigrapsus species will cause it’s local extinction. More likely is that they will learn to live together.
The objective to provide new information about a rarely studied species (Halicarcinus cookii) was fulfilled in this thesis and the information can be used as bases for comparison for future research.
The hypothesis that temperature has no effect on the reproductive rate of crabs was rejected as both study species showed similar increases in brood development rate with increased temperatures. This suggests that global temperature rises may increase the reproductive rate of wider crab populations.
The hypothesis that the arrival, presence and effect of Hemigrapsus takanoi in the Dutch delta waters has had no effect on the native green crab Carcinus maenas was complicated by the fluctuations and the decrease in C. maenas numbers prior to the arrival of H. takanoi. It was concluded that while H. takanoi did not cause the initial decrease in the C. maenas population, it did take advantage of it and now dominates niches previously occupied by juvenile C. maenas where size dependent competition and/or predation on juvenile C. maenas occurs.