Thirty years later, should we be more concerned for the ongoing invasion of Mozambique Tilapia in Australia?

2008 ◽  
Vol 14 (4) ◽  
pp. 235 ◽  
Author(s):  
Robert G. Doupé ◽  
Damien W. Burrows
Keyword(s):  
Exotic Species ◽  
Population Size ◽  
Biological Diversity ◽  
Biogeochemical Cycling ◽  
Individual Species ◽  
Ecological Communities ◽  
Mozambique Tilapia ◽  
Disturbance Regimes ◽  
Agricultural Economies

Exotic speCies complicate the management of native biological diversity and their ecosystems, because their effects are pervasive and varied (Cox 2004). For example, they can be beneficial and integral components of global agricultural economies (Sax et al, 2007), but when unmanaged and by definition invasive, they can negatively change important variables such as the genetics and population size of individual species, the diversity and structure of ecological communities, disturbance regimes and biogeochemical cycling (Vitousek 1990).

scholarly journals The spatial network structure of intertidal meiofaunal communities derived from environmental DNA metabarcoding surveys in Northwest Iberia

2021 ◽  
Author(s):  
Bruno Bellisario ◽  
Maria Fais ◽  
Sofia Duarte ◽  
Pedro Vieira ◽  
Carlos Canchaya ◽  
...  
Keyword(s):  
Biological Diversity ◽  
Scale Up ◽  
Environmental Dna ◽  
Taxonomic Diversity ◽  
Ecosystem Functions ◽  
Individual Species ◽  
Ecological Communities ◽  
Spatial Networks ◽  
Dna Metabarcoding ◽  
High Degree

The identification of the patterns and mechanisms behind species distribution is one of the major challenges in ecology, having also important outcomes for the conservation and management of ecosystems. This is especially true for those components of biodiversity providing essential ecosystem functions and for which standard surveys may underestimate their real taxonomic diversity due to their high degree of cryptic diversity and inherent diagnosis difficulties, such as meiofaunal communities. Environmental DNA (eDNA) metabarcoding may provide a fast and reliable way to refine and scale-up the characterization of biological diversity in complex environmental samples, allowing to bypass such drawbacks and increase the resolution of biodiversity estimates. Moreover, the possibility of integrating eDNA metabarcoding-derived data with tools and methods rooted in network theory would deepen the knowledge of the structuring processes of ecological communities in ways that cannot be predicted from studying individual species/communities in isolation. Here, a sediment eDNA metabarcoding of mitochondrial cytochrome c oxidase I (COI) and the nuclear hypervariable V4 region of the 18S rDNA (18S) was used to reconstruct the spatial networks of intertidal meiofaunal OTUs from three estuaries of North-Western Iberian Peninsula. Null models were used to identify the role of environmental and spatial constraints on the structure of COI- and 18S-derived spatial networks and to characterize the macroecological features of surveyed phyla. Our results show the feasibility of eDNA metabarcoding, not only to capture a fair amount of diversity hard to detect with standard surveys procedures, but also to identify hierarchical spatial structures in intertidal meiofaunal assemblages. This suggests that exclusivity of occurrence rather than pervasiveness appears to be the norm in meiofaunal organisms and that niche-based processes predominantly drive the spatial aggregation and contemporary distribution of meiofaunal phyla within the system.

scholarly journals Avian Community Response to Midrotation Herbicide Release and Prescribed Burning in Conservation Reserve Program Plantations

2008 ◽  
Vol 32 (3) ◽  
pp. 111-119 ◽  
Author(s):  
Brandon Sladek ◽  
L. Burger ◽  
Ian Munn
Keyword(s):  
Loblolly Pine ◽  
Prescribed Burning ◽  
Conservation Reserve Program ◽  
Volume Growth ◽  
Bird Species ◽  
Community Response ◽  
Individual Species ◽  
Avian Community ◽  
Disturbance Regimes ◽  
Pinus Spp

Abstract Former agricultural lands converted to pine (Pinus spp.) plantations in the Conservation Reserve Program (CRP) have potential to provide early successional (ES) habitat for many regionally declining pine/grassland and shrub-successional bird species if actively managed with appropriate disturbance regimes. One such regime is use of the selective herbicide Imazapyr (Arsenal Applicators Concentrate) and prescribed burning, which is permitted on CRP lands and cost share payments are available. This study quantified combined effects of Imazapyr and prescribed fire on the breeding season avian community characteristics and pine volume growth in thinned, midrotation afforested loblolly pine (Pinus taedaL.) plantations in Mississippi. Herbicide treatments were applied in fall of 2002 and winter burns were conducted during winter and early spring of 2002–2003. ES bird species richness was significantly greater in the treated plots compared with controls for both 2003 and 2004. Ten individual species exhibited treatment effects. These responses by ES bird species indicate that midrotation CRPplantations can provide needed ES habitat if treated with appropriate disturbance regimes.

scholarly journals The cryptic impacts of invasion: Functional homogenization of tropical ant communities by invasive fire ants

2019 ◽  
Author(s):  
Mark K. L. Wong ◽  
Benoit Guénard ◽  
Owen T. Lewis
Keyword(s):  
Functional Diversity ◽  
Taxonomic Diversity ◽  
Individual Species ◽  
Ecological Communities ◽  
Ant Communities ◽  
Invasive Insects ◽  
Tropical Grasslands ◽  
Functional Richness ◽  
Functional Identities ◽  
Functional Homogenization

AbstractInvasive insects represent major threats to ecosystems worldwide. Yet their effects on the functional dimension of biodiversity, measured as the diversity and distribution of traits, are overlooked. Such measures often determine the resilience of ecological communities and the ecosystem processes they modulate. The fire ant Solenopsis invicta is a highly problematic invasive species occurring on five continents. Its impacts on the taxonomic diversity of native ant communities have been studied but its impacts on their functional diversity are unknown. Comparing invaded and uninvaded plots in tropical grasslands of Hong Kong, we investigated how the presence of S. invicta affects the diversity and distribution of ant species and traits within and across communities, the functional identities of communities, and functionally unique species. We calculated the functional diversity of individual species, including the trait variation from intraspecific polymorphisms, and scaled up these values to calculate functional diversity at the community level. Invasion had only limited effects on species richness and functional richness, which were 13% and 8.5% lower in invaded communities respectively. In contrast, invasion had pronounced effects on taxonomic and functional composition due to turnover in species and trait values. Furthermore, invaded communities were functionally more homogeneous, displaying 23% less turnover and 56% more redundancy than uninvaded communities, as well as greater clustering and lower divergence in trait values. Invaded communities had fewer functionally-unique individuals and were characterized by ant species with narrower heads and bodies and shorter mandibles. Our results suggest that studies based only on taxonomic measures of diversity or indices describing trait variety risk underestimating the full ramifications of invasions. Investigating the diversity and distributions of traits at species, community and landscape levels can reveal the cryptic impacts of alien species which, despite causing little taxonomic change, may substantially modify the structure and functioning of ecological communities.

Community Ecology

Ecology ◽  
2012 ◽  
Author(s):  
Herman A. Verhoef
Keyword(s):  
Community Ecology ◽  
Evolutionary Biology ◽  
Environmental Gradients ◽  
Functional Integration ◽  
Species Abundance ◽  
Functional Trait ◽  
Individual Species ◽  
Global Changes ◽  
Ecological Communities ◽  
Early 21St Century

At the beginning of the 20th century there was much debate about the “nature” of communities. The driving question was whether the community was a self-organized system of co-occurring species or simply a haphazard collection of populations with minimal functional integration. At that time, two extreme views dominated the discussion: one view considered a community as a superorganism, the member species of which were tightly bound together by interactions that contributed to repeatable patterns of species abundance in space and time. This concept led to the assumption that communities are fundamental entities, to be classified as the Linnaean taxonomy of species. Frederick E. Clements was one of the leading proponents of this approach, and his view became known as the organismic concept of communities. This assumes a common evolutionary history for the integrated species. The opposite view was the individualistic continuum concept, advocated by H. A. Gleason. His focus was on the traits of individual species that allow each to live within specific habitats or geographical ranges. In this view a community is an assemblage of populations of different species whose traits allow persisting in a prescribed area. The spatial boundaries are not sharp, and the species composition can change considerably. Consequently, it was discussed whether ecological communities were sufficiently coherent entities to be considered appropriate study objects. Later, consensus was reached: that properties of communities are of central interest in ecology, regardless of their integrity and coherence. From the 1950s and 1960s onward, the discussion was dominated by the deterministic outcome of local interactions between species and their environments and the building of this into models of communities. This approach, indicated as “traditional community ecology,” led to a morass of theoretical models, without being able to provide general principles about many-species communities. Early-21st-century approaches to bringing general patterns into community ecology concern (1) the metacommunity approach, (2) the functional trait approach, (3) evolutionary community ecology, and (4) the four fundamental processes. The metacommunity approach implicitly recognizes and studies the important role of spatiotemporal dynamics. In the functional trait approach, four themes are focused upon: traits, environmental gradients, the interaction milieu, and performance currencies. This functional, trait-focused approach should have a better prospect of understanding the effects of global changes. Evolutionary community ecology is an approach in which the combination of community ecology and evolutionary biology will lead to a better understanding of the complexity of communities and populations. The four fundamental processes are selection, drift, speciation, and dispersal. This approach concerns an organizational scheme for community ecology, based on these four processes to describe all existing specific models and frameworks, in order to make general statements about process–pattern connections.

Climate change and protected area policy and planning in Canada

2005 ◽  
Vol 81 (5) ◽  
pp. 696-703 ◽  
Author(s):  
Daniel Scott ◽  
Christopher Lemieux
Keyword(s):  
Climate Change ◽  
Protected Areas ◽  
Biological Diversity ◽  
Convention On Biological Diversity ◽  
Ecological Communities ◽  
Key Words Climate Change ◽  
United Nations Convention ◽  
Policy And Planning ◽  
Potential Shifts

Protected areas are the most common and most important strategy for biodiversity conservation and are called for under the United Nations' Convention on Biological Diversity. However, most protected areas have been designed to represent (and in theory protect for perpetuity) specific natural features, species and ecological communities in-situ, and have not taken into account potential shifts in ecosystem distribution and composition that could be induced by global climatic change. This paper provides an overview of the policy and planning implications of climate change for protected areas in Canada, summarizes a portfolio of climate change adaptation options that have been discussed in the conservation literature and by conservation professionals and provides a perspective on what is needed for the conservation community in Canada to move forward on responding to the threat posed by climate change. Key words: climate change, protected areas, parks, conservation, system planning, impacts, adaptation

The value of managing for biodiversity

1992 ◽  
Vol 68 (2) ◽  
pp. 225-237 ◽  
Author(s):  
P. J. Burton ◽  
A. C. Balisky ◽  
L. P. Coward ◽  
D. D. Kneeshaw ◽  
S. G. Cumming
Keyword(s):  
Climate Change ◽  
Natural Products ◽  
Environmental Ethics ◽  
Biological Diversity ◽  
Genetic Material ◽  
Ecological Indicators ◽  
Individual Species ◽  
Multiple Use ◽  
Integrated Resource Management ◽  
Management Indicator Species

The concept of biological diversity (biodiversity) is reviewed, with special attention to its measurement and natural trends. While generalizations regarding the necessity of biodiversity need to be interpreted with caution, it is argued that biodiversity should be protected in more ecosystem and landscape reserves, and that biodiversity is a reasonable management objective on timber lands as well. Maintaining biodiversity is important because we cannot always identify which individual species are critical to ecosystem sustainability, nor which species may be useful to mankind in future. Many wild species can provide useful natural products and genetic material, and can serve as ecological indicators. Diversity reduces pest and disease problems, and encourages recovery from disturbance. Uncertainty exists with regard to climate change and future socioeconomic values. It is therefore prudent to maximize flexibility by promoting a wide array of species and potential products. Suggestions are offered on how to promote biodiversity in multiple-use forests. Key words: biological diversity, climate change, environmental ethics, forest inventory, genetic conservation, integrated resource management, indicator species, landscape ecology, multiple-use, natural products, stability, uncertainty.

scholarly journals Antarctic ecosystem monitoring: quantifying the response of ecosystem indicators to variability in Antarctic krill

2005 ◽  
Vol 62 (3) ◽  
pp. 366-373 ◽  
Author(s):  
Keith Reid ◽  
John P. Croxall ◽  
Dirk R. Briggs ◽  
Eugene J. Murphy
Keyword(s):  
Linear Relationship ◽  
Population Size ◽  
Antarctic Krill ◽  
Reference Points ◽  
Trophic Levels ◽  
Prey Abundance ◽  
Individual Species ◽  
Predator Species ◽  
Krill Abundance ◽  
Ecosystem Indicators

Abstract The utility of upper-trophic-level species as ecosystem indicators is determined by our ability to relate changes in indices of their performance to changes at lower trophic levels. Such relationships were assessed using indices of predator performance (response vectors) for four predator species, together with independent ship-based acoustic estimates of abundance of their main prey, Antarctic krill (Euphausia superba), from South Georgia in the South Atlantic Ocean. Out of 32 response vectors investigated, 13 showed a significant non-linear relationship, based on a Holling Type II response, to krill abundance, and just five showed a significant linear relationship. Predator responses reflecting the processes during summer, when prey surveys were undertaken, showed the closest relationship with prey abundance. Distinct relationships existed between the variability of indices and the biological processes they measured. Body mass variables had the lowest variability (CVs <10%), whereas those measuring breeding success showed the greatest variability (CVs >50%). Multivariate indices, produced by combining response vectors from all four predator species into a single combined index, provided a better fit with krill data than any of the individual vectors. Whereas population size parameters for individual species showed no relationship with annual estimates of krill abundance, a combined, multispecies population size index did show a significant response. Understanding the form of the relationship between concurrent indicators of prey abundance and key ecosystem metrics/reference points, such as population size, is crucial to the application of monitoring data to management action.

scholarly journals On the temporally flexible structure of plant-pollinator interaction networks

2020 ◽  
Author(s):  
Paul J. CaraDonna ◽  
Nickolas M. Waser
Keyword(s):  
Temporal Variation ◽  
Network Structure ◽  
Species Interactions ◽  
Interspecific Interactions ◽  
Activity Period ◽  
Individual Species ◽  
Ecological Communities ◽  
Short Term ◽  
Temporal Flexibility ◽  
Plant Pollinator

AbstractEcological communities consist of species that are joined in complex networks of interspecific interaction. The interactions that networks depict often form and dissolve rapidly, but this temporal variation is not well integrated into our understanding of the causes and consequences of network structure. If interspecific interactions exhibit temporal flexibility across time periods over which organisms co-occur, then the emergent structure of the corresponding network may also be temporally flexible, something that a temporally-static perspective would miss. Here, we use an empirical system to examine short-term flexibility in network structure (connectance, nestedness, and specialization), and in individual species interactions that contribute to that structure. We investigated weekly plant-pollinator networks in a subalpine ecosystem across three summer growing seasons. To link the interactions of individual species to properties of their networks, we examined weekly temporal variation in species’ contributions to network structure. As a test of the potential robustness of networks to perturbation, we also simulated the random loss of species from weekly networks. We then compared the properties of weekly networks to the properties of cumulative networks that aggregate field observations over each full season. A week-to-week view reveals considerable flexibility in the interactions of individual species and their contributions to network structure. For example, species that would be considered relatively generalized across their entire activity period may be much more specialized at certain times, and at no point as generalized as the cumulative network may suggest. Furthermore, a week-to-week view reveals corresponding temporal flexibility in network structure and potential robustness throughout each summer growing season. We conclude that short-term flexibility in species interactions leads to short-term variation in network properties, and that a season-long, cumulative perspective may miss important aspects of the way in which species interact, with implications for understanding their ecology, evolution, and conservation.

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