Research

1228 KiB

Open AccessArticle

Extinction Resilience of Island Species: An Amphibian Case and a Predictive Model

by Cristian R. Altaba

Diversity 2014, 6(1), 43-71; https://doi.org/10.3390/d6010043 - 08 Jan 2014

Cited by 3 | Viewed by 8898

Extreme overall divergence and high extinction rates are typical of insular endemics. Thus, detecting and understanding nativeness is critical on islands. Resilience to extinction is explored through a mechanistic approach focusing on midwife toads (Anura: Alytidae: Alytinae), an ancient lineage that includes continental [...] Read more.

Extreme overall divergence and high extinction rates are typical of insular endemics. Thus, detecting and understanding nativeness is critical on islands. Resilience to extinction is explored through a mechanistic approach focusing on midwife toads (Anura: Alytidae: Alytinae), an ancient lineage that includes continental and insular species. All alytines need urgent conservation action, including control of emerging diseases and spatially explicit reserve design aimed at ensuring ecosystem health and connectivity. The only extant insular alytine is additionally affected by an introduced continental predator. This alien species acts as a driver of the prey’s near-extinction and has not elicited any evolutionary response. Both IUCN criteria and EDGE scores show that alytines are top conservation priorities. However, there is a need for also considering phenotypic and ecological uniqueness in the assessment of conservation status and urgency. The reason is that phenotypes render ecosystems functional and insular ones uniquely so. In contrast, phylogenetic relatedness is just a constraint upon, not a motor of, evolutionary novelty. Insular species are indeed particularly susceptible, but can be similarly endangered as continental ones. This paradox may be solved by recognizing the insularity syndrome in any isolated or nearly-insular ecosystem, as a function of evolutionary and dispersal potentials. This predictive model may be useful for island biogeography, invasion biology and conservation planning. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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1228 KiB

Open AccessArticle

A Proposed Revision of Diversity Measures

by Vic Semeniuk and Ian David Cresswell

Diversity 2013, 5(3), 613-626; https://doi.org/10.3390/d5030613 - 09 Aug 2013

Cited by 6 | Viewed by 8667

Abstract

The current measures of diversity for vegetation, namely alpha, beta, and gamma diversity are not logically consistent, which reduces their effectiveness as a framework for comparative vegetation analysis. The current terms mix concepts: specifically, while alpha diversity measures floristic diversity at a site, [...] Read more.

The current measures of diversity for vegetation, namely alpha, beta, and gamma diversity are not logically consistent, which reduces their effectiveness as a framework for comparative vegetation analysis. The current terms mix concepts: specifically, while alpha diversity measures floristic diversity at a site, and gamma diversity measures floristic diversity regionally, beta diversity is a measure of diversity between two sites and measures a different phenomenon. We seek to rationalise measures of diversity providing a scalar set of measures. Our approach recognises vegetation diversity extends beyond species diversity and should include the various ways plants express themselves phenotypically. We propose four types of diversity, with a new set of prefixes: Type 1 diversity = the largest scale−the regional species pool; Type 2 diversity = the large habitat scale−where species in a habitat have been selected from the regional species pool; Type 3 diversity = intra-habitat expression of floristics, structure, and physiognomy; and Type 4 diversity = the finest scale of expression of vegetation diversity reflecting site selection of floristics, physiography, and phenotypic expression and reproductive strategy. This proposed framework adds significant new power to measures of diversity by extending the existing components to cover floristics, structure, physiognomy, and other forms of phenotypic expression. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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616 KiB

Open AccessArticle

Effects of Dispersal-Related Factors on Species Distribution Model Accuracy for Boreal Lake Ecosystems

by Simon Hallstan, Richard K. Johnson and Leonard Sandin

Diversity 2013, 5(2), 393-408; https://doi.org/10.3390/d5020393 - 31 May 2013

Cited by 6 | Viewed by 9371

Abstract

Species distribution modeling is used in applied ecology; for example in predicting the consequences of global change. However, questions still remain about the robustness of model predictions. Here we estimate effects of landscape spatial configuration and organism flight ability—factors related to dispersal—on the [...] Read more.

Species distribution modeling is used in applied ecology; for example in predicting the consequences of global change. However, questions still remain about the robustness of model predictions. Here we estimate effects of landscape spatial configuration and organism flight ability—factors related to dispersal—on the accuracy of species distribution models. Distribution models were developed for 129 phytoplankton taxa, 164 littoral invertebrate taxa and 44 profundal invertebrate taxa sampled in 105 Swedish lakes, using six different modeling techniques (generalized linear models (GLM), multivariate adaptive regression splines (MARS), classification tree analysis (CTA), mixture discriminant analysis (MDA), generalized boosting models (GBM) and random forests (RF)). Model accuracy was not affected by dispersal ability (i.e., invertebrate flight ability), but the accuracy of phytoplankton assemblage predictions and, to a lesser extent, littoral invertebrate assemblages were related to ecosystem size and connectivity. Although no general pattern across species or spatial configuration was evident from our study, we recommend that dispersal and spatial configuration of ecosystems should be considered when developing species distribution models. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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1880 KiB

Open AccessArticle

Conservation of Protists: The Krauthügel Pond in Austria

by Fenton P.D. Cotterill, Hannes Augustin, Reinhard Medicus and Wilhelm Foissner

Diversity 2013, 5(2), 374-392; https://doi.org/10.3390/d5020374 - 21 May 2013

Cited by 6 | Viewed by 11637

Abstract

Although constituting more than 100,000 described species, protists are virtually ignored within the arena of biodiversity conservation. One reason is the widespread belief that the majority of protists have cosmopolitan distributions, in contrast to the highly hetereogenous biogeography of the “mega-Metazoa”. However, modern [...] Read more.

Although constituting more than 100,000 described species, protists are virtually ignored within the arena of biodiversity conservation. One reason is the widespread belief that the majority of protists have cosmopolitan distributions, in contrast to the highly hetereogenous biogeography of the “mega-Metazoa”. However, modern research reveals that about one third of the known protists have restricted distributions, which endorses their conservation, at least in special cases. Here, we report what probably ranks as the first successful conservation intervention focused directly on known protist diversity. It is justified by unique species, type localities, and landscape maintenance as evidence for legislation. The protected habitat comprises an ephemeral pond, which is now a “Natural Monument” for ciliated protozoa. This wetland occupies a natural depression on the Krauthügel (“cabbage hill”) south of the fortress of Salzburg City. When filled, the claviform pond has a size of ~30 × 15 m and a depth rarely surpassing 30 cm. Water is present only for some days or weeks, depending on heavy and/or prolonged rain. The pond occupied an agricultural field where root and leafy vegetables were cultivated for possibly more than 200 years. In the 1960s, this area became a grassland utilized as an autumn pasture, but was abandoned in the 1990s. Repeated sampling between 1982 and 2012 recovered a total of at least 150 ciliate taxa, of which 121 were identified to species level. Eight species were new to science, and an additional 10 poorly known species were reinvestigated and neotypified with populations from the Krauthügel pond. Both endemism and type localities justify the argument that the “integrative approach” in biodiversity and conservation issues should include protists and micro-metazoans. We argue that Krauthügel holds a unique reference node for biodiversity inventories to obtain the baseline knowledge—which is the prerequisite to monitor ecosystem integrity—and detect and evaluate impacts of natural and anthropogenic disturbances. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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2493 KiB

Open AccessArticle

Biodiversity Indicators Show Climate Change Will Alter Vegetation in Parks and Protected Areas

by Keith R. Holmes, Trisalyn A. Nelson, Nicholas C. Coops and Michael A. Wulder

Diversity 2013, 5(2), 352-373; https://doi.org/10.3390/d5020352 - 16 May 2013

Cited by 11 | Viewed by 8962

Abstract

While multifaceted, a chief aim when designating parks and protected areas is to support the preservation of biological diversity, in part, through representing and conserving the full range of landscape conditions observed throughout a representative area. Parks and protected areas are, however, typically [...] Read more.

While multifaceted, a chief aim when designating parks and protected areas is to support the preservation of biological diversity, in part, through representing and conserving the full range of landscape conditions observed throughout a representative area. Parks and protected areas are, however, typically developed using a static interpretation of current biodiversity and landscape conditions. The observed and potential climate change impacts to biodiversity have created a need to also contemplate how parks and protected areas will respond to climate change and how these areas will represent the future range of landscape conditions. To assess change in biodiversity, broad-scale ecosystem information can be sourced from indirect remotely sensed indicators. Quantifying biodiversity through indirect indicators allows characterization of inter-relationships between climate and biodiversity. Such characterizations support the assessment of possible implications of climatic change, as the indicators can be generated using modeled forecasts of future climatic conditions. In this paper we model and map impacts of climate change on British Columbia’s parks and protected areas by quantifying change in a number of remotely sensed indicators of biodiversity. These indicators are based on the measured amount of incoming solar energy used by vegetation and map the overall annual energy utilization, variability (seasonality), and latent or baseline energy. We compare current conditions represented by parks and protected areas, to those forecasted in the year 2065. Our results indicate that parks and protected areas are forecasted to become more productive and less seasonal, due to increased vegetation productivity in higher elevation environments. While increased vegetation productivity may be beneficial for biodiversity overall, these changes will be particularly problematic for sensitive and specialist species. Future gaps in vegetation conditions protected by parks and protected areas are observed in the eastern edge of the Rocky Mountains and the central interior region of British Columbia. Protected areas along the Coast Mountains, Vancouver Island highlands, and the Rocky Mountains show the greatest levels of change in the biodiversity indicators, including decreasing seasonality, with the Mountain Hemlock ecozone most at risk. Examples of large parks that are predicted to experience rapid change in vegetation characteristics include Strathcona, Garabaldi, and Kitlope. Our maps of future spatial distributions of indirect biodiversity indicators fill a gap in information products available for adaptive parks management and provide an opportunity for dialogue and further research on the use of future scenarios of landscape conditions in conservation planning. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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1841 KiB

Open AccessArticle

Evolutionary Hotspots in the Mojave Desert

by Amy G. Vandergast, Richard D. Inman, Kelly R. Barr, Kenneth E. Nussear, Todd C. Esque, Stacie A. Hathaway, Dustin A. Wood, Philip A. Medica, Jesse W. Breinholt, Catherine L. Stephen, Andrew D. Gottscho, Sharyn B. Marks, W. Bryan Jennings and Robert N. Fisher

Diversity 2013, 5(2), 293-319; https://doi.org/10.3390/d5020293 - 15 Apr 2013

Cited by 34 | Viewed by 11771

Abstract

Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When [...] Read more.

Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed species show spatial overlap in high genetic diversity and divergence, these regions can be considered evolutionary hotspots. We mapped spatial population genetic structure for 17 animal species across the Mojave Desert, USA. We analyzed these in concurrence and located 10 regions of high genetic diversity, divergence or both among species. These were mainly concentrated along the western and southern boundaries where ecotones between mountain, grassland and desert habitat are prevalent, and along the Colorado River. We evaluated the extent to which these hotspots overlapped protected lands and utility-scale renewable energy development projects of the Bureau of Land Management. While 30–40% of the total hotspot area was categorized as protected, between 3–7% overlapped with proposed renewable energy project footprints, and up to 17% overlapped with project footprints combined with transmission corridors. Overlap of evolutionary hotspots with renewable energy development mainly occurred in 6 of the 10 identified hotspots. Resulting GIS-based maps can be incorporated into ongoing landscape planning efforts and highlight specific regions where further investigation of impacts to population persistence and genetic connectivity may be warranted. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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688 KiB

Open AccessArticle

Edges and Overlaps in Northwest Atlantic Phylogeography

by Safra Altman, John D. Robinson, James M. Pringle, James E. Byers and John P. Wares

Diversity 2013, 5(2), 263-275; https://doi.org/10.3390/d5020263 - 11 Apr 2013

Cited by 18 | Viewed by 7342

Abstract

As marine environments change, the greatest ecological shifts—including resource usage and species interactions—are likely to take place in or near regions of biogeographic and phylogeographic transition. However, our understanding of where these transitional regions exist depends on the defining criteria. Here we evaluate [...] Read more.

As marine environments change, the greatest ecological shifts—including resource usage and species interactions—are likely to take place in or near regions of biogeographic and phylogeographic transition. However, our understanding of where these transitional regions exist depends on the defining criteria. Here we evaluate phylogeographic transitions using a bootstrapping procedure that allows us to focus on either the strongest genetic transitions between a pair of contiguous populations, versus evaluation of transitions inclusive of the entire overlap between two intraspecific genetic lineages. We compiled data for the Atlantic coast of the United States, and evaluate taxa with short- and long-dispersing larval phases separately. Our results are largely concordant with previous biogeographic and phylogeographic analyses, indicating strong biotic change associated with the regions near Cape Cod, the Delmarva Peninsula, and eastern Florida. However, inclusive analysis of the entire range of sympatry for intraspecific lineages suggests that broad regions—the Mid-Atlantic Bight and eastern Florida–already harbor divergent intraspecific lineages, suggesting the potential for ecological evaluation of resource use between these lineages. This study establishes baseline information for tracking how such patterns change as predicted environmental changes take place. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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7515 KiB

Open AccessArticle

Biogeography of the Cicadas (Hemiptera: Cicadidae) of North America, North of Mexico

by Allen F. Sanborn and Polly K. Phillips

Diversity 2013, 5(2), 166-239; https://doi.org/10.3390/d5020166 - 09 Apr 2013

Cited by 41 | Viewed by 22603

Abstract

We describe and illustrate the biogeography of the cicadas inhabiting continental North America, north of Mexico. Species distributions were determined through our collecting efforts as well as label data from more than 110 institutional collections. The status of subspecies is discussed with respect [...] Read more.

We describe and illustrate the biogeography of the cicadas inhabiting continental North America, north of Mexico. Species distributions were determined through our collecting efforts as well as label data from more than 110 institutional collections. The status of subspecies is discussed with respect to their distributions. As we have shown over limited geographic areas, the distribution of individual species is related to the habitat in which they are found. We discuss the biogeography of the genera with respect to their phylogenetic relationships. California is the state with the greatest alpha diversity (89 species, 46.6% of taxa) and unique species (35 species, 18.3% of taxa). Texas, Arizona, Colorado and Utah are the states with the next greatest alpha diversity with Texas, Arizona and Utah being next for unique species diversity. Maine, New Hampshire and Rhode Island are the states with the least amount of cicada diversity. Diversity is greatest in states and areas where there is a diversity of plant communities and habitats within these communities. Mountainous terrain also coincides with increases in diversity. Several regions of the focus area require additional collection efforts to fill in the distributions of several species. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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788 KiB

Open AccessArticle

Setting Conservation Priorities in a Widespread Species: Phylogeographic and Physiological Variation in the Lake Chub, Couesius plumbeus (Pisces: Cyprinidae)

by Eric B. Taylor, Charles-A. Darveau and Patricia M. Schulte

Diversity 2013, 5(2), 149-165; https://doi.org/10.3390/d5020149 - 02 Apr 2013

Cited by 12 | Viewed by 6678

Abstract

Defining units of conservation below the species level is a widely accepted conservation priority, but is especially challenging for widespread taxa that have experienced diverse geographic histories and exist across heterogenous environments. The lake chub (Pisces: Couesius plumbeus) is a widespread freshwater [...] Read more.

Defining units of conservation below the species level is a widely accepted conservation priority, but is especially challenging for widespread taxa that have experienced diverse geographic histories and exist across heterogenous environments. The lake chub (Pisces: Couesius plumbeus) is a widespread freshwater fish in North America and occurs from the southcentral USA to northwestern Alaska and Canada. We used mtDNA sequence analysis to test for divergent lineages predicted to occur as a result of survival of lake chub in distinct glacial refugia. Lake chub consisted of two major mtDNA lineages separated by 3.8% sequence divergence which are probably late to pre-Pleistocene in origin. We combined these data with those consistent with thermal adaptation in fish living in thermal springs versus those living in a lake with wide seasonal temperature variation, and with data on distribution of lake chub in major watershed units. We assessed these data against objective criteria developed to identify conservation units under Canadian endangered species legislation. Our analysis identified twelve major units of conservation within C. plumbeus that could be assessed under Canada’s Species-at-Risk Act. Our study illustrates how different character traits manifested at very different spatial scales can be used to define conservation units within widely-distributed taxa. Full article

(This article belongs to the Special Issue Biogeography and Biodiversity Conservation)

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