We present a consensus classification of life to embrace the more than 1.6 million species already provided by more than 3,000 taxonomists' expert opinions in a unified and coherent, hierarchically ...ranked system known as the Catalogue of Life (CoL). The intent of this collaborative effort is to provide a hierarchical classification serving not only the needs of the CoL's database providers but also the diverse public-domain user community, most of whom are familiar with the Linnaean conceptual system of ordering taxon relationships. This classification is neither phylogenetic nor evolutionary but instead represents a consensus view that accommodates taxonomic choices and practical compromises among diverse expert opinions, public usages, and conflicting evidence about the boundaries between taxa and the ranks of major taxa, including kingdoms. Certain key issues, some not fully resolved, are addressed in particular. Beyond its immediate use as a management tool for the CoL and ITIS (Integrated Taxonomic Information System), it is immediately valuable as a reference for taxonomic and biodiversity research, as a tool for societal communication, and as a classificatory "backbone" for biodiversity databases, museum collections, libraries, and textbooks. Such a modern comprehensive hierarchy has not previously existed at this level of specificity.
Abstract Changes and needs in marine science (and natural science in general) training over the past six decades are discussed. Among these are: new technological advances; the loss of -ology ...courses; the loss of field courses and sense of place opportunities for students; the need for a more interdisciplinary approach to training natural science students; a need to better expose our students to threats to Earth’s biocultural diversity; a need to include more humanities in our student training, including addressing diminished readership and appreciation of the great books; the nature of creativity; the perils of the internet; and university emphasis on faculty overhead dollars and high-profile publications at the expense of student training and more creative research.
Tropicalization is a term used to describe the transformation of temperate ecosystems by poleward-moving tropical organisms in response to warming temperatures. In North America, decreases in the ...frequency and intensity of extreme winter cold events are expected to allow the poleward range expansion of many cold-sensitive tropical organisms, sometimes at the expense of temperate organisms. Although ecologists have long noted the critical ecological role of winter cold temperature extremes in tropical–temperate transition zones, the ecological effects of extreme cold events have been understudied, and the influence of warming winter temperatures has too often been left out of climate change vulnerability assessments. Here, we examine the influence of extreme cold events on the northward range limits of a diverse group of tropical organisms, including terrestrial plants, coastal wetland plants, coastal fishes, sea turtles, terrestrial reptiles, amphibians, manatees, and insects. For these organisms, extreme cold events can lead to major physiological damage or landscape-scale mass mortality. Conversely, the absence of extreme cold events can foster population growth, range expansion, and ecological regime shifts. We discuss the effects of warming winters on species and ecosystems in tropical–temperate transition zones. In the 21st century, climate change-induced decreases in the frequency and intensity of extreme cold events are expected to facilitate the poleward range expansion of many tropical species. Our review highlights critical knowledge gaps for advancing understanding of the ecological implications of the tropicalization of temperate ecosystems in North America.
Introduction: Places with high species diversity have high linguistic diversity, whereas areas with low species diversity tend to have low linguistic diversity. Objective: To characterize the ...intriguing relationship between biological and cultural diversity, a correlation that has been discussed at a global scale, but here tested for the first time in Mexico. Methods: We compiled exhaustive databases on both endangered species and endangered languages, and reviewed available literature on Mexico’s biocultural diversity with a focus on endangered and critically endangered species and languages. Results: With 364 living languages, Mexico is the world’s fifth most linguistically diverse country, but 64 of these languages are facing a very high risk of disappearance and 13 have already disappeared. Mexico is also the fourth most biologically diverse country, but 1 213 species of its flora and fauna are threatened with extinction and at least 127 species were recently extinct. Conclusions: Indigenous peoples are custodians of much of the world’s biocultural diversity. As the world grows less linguistically and culturally diverse, it is also becoming less biologically diverse. Mexico’s biological and linguistic diversity show strong geographic overlap, with the states of Oaxaca, Chiapas, Veracruz, Guerrero, and Michoacán harboring most species and most languages. Similarly, Mexico’s biodiversity hotspots mirror language hotspots, and areas with the highest number of endangered species overlap with areas where the endangerment of languages is also the highest.
A review of published research indicates that the Northern Gulf of California is, historically and currently, one of the most biologically productive marine regions on Earth. This high productivity ...is driven by a unique mix of factors, including: coastal upwelling, wind-driven mixing, extreme tidal mixing and turbulence, thermohaline circulation that moves intermediate waters into the mixed layer, coastal-trapped waves, regular sediment resuspension, and, to a lesser extent, agricultural runoff, released nutrients from erosion of ancient Colorado River Delta sediments, and perhaps input from decomposing tidal-flat plant debris. It has been suggested that decreased Colorado River flow, due to anthropogenic water impoundments and diversions, has had a negative impact on the health of the Northern Gulf of California ecosystem, particularly by reducing primary productivity and/or stock production of finfish and shellfish. However, there is no evidence that surface flow from the Colorado River is now, nor has ever been an important driver of primary productivity in the Northern Gulf, and nutrient/chlorophyll studies show no relationship to Colorado River flow (or, if anything, reduced nutrient/chlorophyll levels occur during high river-flow periods). And, there is very limited and equivocal evidence to support the claim that reduced river flow has significantly impacted secondary productivity in the Northern Gulf. The marine ecosystem of the Northern Gulf remains rich in nutrients, high in biodiversity and productivity, and appears to continue to be healthy, except for the impacts of historical and current fisheries. Human extraction of shrimp, Gulf corvina, totoaba (largely illegally), and other marine resources, remain very high in this region. There also is no evidence that reduced Colorado River flow has negatively impacted the health of the critically endangered vaquita porpoise, and assertions that it has done so deflect attention from the actual cause of decline—bycatch in legal and illegal gillnet fisheries. A review of Colorado River Delta research confirms that, historically and perhaps as long as the river has reached the Gulf of California, there have been long periods of no flow, or greatly reduced flow to the sea. Thus, the ecosystem is historically adapted to broadly fluctuating river flows and elevated salinities. Although commonly used by recent researchers, measurements of Colorado River water crossing the border into Mexico do not provide a reliable proxy for how much water (if any) actually reaches the Upper Gulf because of the complex nature of internal basins and diversions in the region.
The few studies that have addressed past effects of climate change on species distributions have mostly focused on plants due to the rarity of historical faunal baselines. However, hyperdiverse ...groups like Arthropoda are vital to monitor in order to understand climate change impacts on biodiversity. This is the first investigation of ground-dwelling arthropod (GDA) assemblages along the full elevation gradient of a mountain range in the Madrean Sky Island Region, establishing a baseline for monitoring future changes in GDA biodiversity. To determine how GDA assemblages relate to elevation, season, abiotic variables, and corresponding biomes, GDA were collected for two weeks in both spring (May) and summer (September) 2011 in the Santa Catalina Mountains, Arizona, using pitfall traps at 66 sites in six distinct upland (non-riparian/non-wet canyon) biomes. Four arthropod taxa: (1) beetles (Coleoptera), (2) spiders (Araneae), (3) grasshoppers and crickets (Orthoptera), and (4) millipedes and centipedes (Myriapoda) were assessed together and separately to determine if there are similar patterns across taxonomic groups. We collected 335 species of GDA: 192/3793 (species/specimens) Coleoptera, 102/1329 Araneae, 25/523 Orthoptera, and 16/697 Myriapoda. GDA assemblages differed among all biomes and between seasons. Fifty-three percent (178 species) and 76% (254 species) of all GDA species were found in only one biome and during only one season, respectively. While composition of arthropod assemblages is tied to biome and season, individual groups do not show fully concordant patterns. Seventeen percent of the GDA species occurred only in the two highest-elevation biomes (Pine and Mixed Conifer Forests). Because these high elevation biomes are most threatened by climate change and they harbor a large percentage of unique arthropod species (11-25% depending on taxon), significant loss in arthropod diversity is likely in the Santa Catalina Mountains and other isolated mountain ranges in the Southwestern US.
Environmental DNA (eDNA) metabarcoding is revolutionizing biodiversity monitoring, but comparisons against traditional data rarely include long-term historical inventories. We targeted eukaryotes by ...amplifying a fragment of the 18S gene from eDNA isolated from seawater samples at 20 sites in the Gulf of California (GC) and contrasted regional taxonomic diversity against 316 simultaneous visual surveys and a historical database with over 5k species. From 61k Amplified Sequence Variants, we identified 850 eukaryotic families, of which half represent new compiled records, including 174 families of planktonic, benthic, and parasitic invertebrates. The 18S eDNA metabarcoding analysis revealed many overseen taxa, highlighting higher taxonomic ranks within micro-invertebrates, microscopic fungi, and other micro-eukaryotes from the supergroups Stramenopiles, Alveolata, and Rhizaria. The database combining all methods has doubled the number of distinct phyla, classes, and orders compared to the historical baseline, indicating biodiversity levels in the GC are much higher than previously assumed. The estimated proportion of historical taxa included in public reference databases was only 18% for species, partially explaining the small portion of 18S eDNA reads that were taxonomically assigned to species level (13%). Each method showed different taxonomic biases, with 18S eDNA metabarcoding detecting few vertebrates, visual surveys targeting only seven metazoan phyla, and the historical records focusing on macroinvertebrates, fish, and algae. Although all methods recovered the main known biogeographic regionalization, the 18S eDNA metabarcoding data did not support the historical pattern of higher diversity in the Central than Northern GC. While combining methods provides a novel view of biodiversity that is much more comprehensive than any individual approach, our study highlights many challenges in synthesizing biodiversity data from traditional and novel sources.
Models analyzing how Southwestern plant communities will respond to climate change predict that increases in temperature will lead to upward elevational shifts of montane species. We tested this ...hypothesis by reexamining Robert Whittaker's 1963 plant transect in the Santa Catalina Mountains of southern Arizona, finding that this process is already well underway. Our survey, five decades after Whittaker's, reveals large changes in the elevational ranges of common montane plants, while mean annual rainfall has decreased over the past 20 years, and mean annual temperatures increased 0.25°C/decade from 1949 to 2011 in the Tucson Basin. Although elevational changes in species are individualistic, significant overall upward movement of the lower elevation boundaries, and elevational range contractions, have occurred. This is the first documentation of significant upward shifts of lower elevation range boundaries in Southwestern montane plant species over decadal time, confirming that previous hypotheses are correct in their prediction that mountain communities in the Southwest will be strongly impacted by warming, and that the Southwest is already experiencing a rapid vegetation change.
We re‐examined Robert Whittaker's 1963 plant transect in the Santa Catalina Mountains of southern Arizona, finding large changes in the elevational ranges of common montane plants over the past 5 decades, during which time mean annual temperatures have increased significantly. Although elevational changes of species are individualistic, significant overall upward movement of the lower elevation boundaries, and elevational range contractions, have occurred. This study confirms that previous hypotheses are correct in their prediction that mountain communities in the Southwest will be strongly impacted by warming, and that the Southwest is already experiencing a rapid vegetation change.
As marine systems are threatened by increasing human impacts, mechanisms to maintain biodiversity and ecosystem functions and services are needed. Protecting areas of conservation importance may ...serve as a proxy for maintaining these functions, while also facilitating efficient use and management of limited resources. Biodiversity hotspots have been used as surrogates for spatial conservation importance; however, as many protected areas have been established opportunistically and under differing criteria, it is unclear how well they actually protect hotspots. We evaluated how well the current protected area network and priority areas selected through previous systematic conservation planning exercises preserve biodiversity hotspots in the Gulf of California, Mexico. We also determined spatial congruence between biodiversity hotspots based on different criteria, which may determine their ability to be used as surrogates for each other. We focus on the Gulf of California because it is a megadiverse system where limited information regarding species diversity and distribution has constrained development of strategies for conservation and management. We developed a species occurrence database and identified biodiversity hotspots using four different criteria: species richness, rarity, endemism, and threatened species. We interpolated species occurrence, while accounting for heterogeneous sampling efforts. We then assessed overlap of hotspots with existing protected areas and priority areas, and between hotspots derived by distinct criteria. We gathered 286,533 occurrence records belonging to 12,105 unique species, including 6388 species identified as rare, 642 as endemic, and 386 as threatened. We found that biodiversity hotspots showed little spatial overlap with areas currently under protection and previously identified priority areas. Our results highlight the importance of distinct spatial areas of biodiversity and suggest that different ecological mechanisms sustain different aspects of diversity and multiple criteria should be used when defining conservation areas.
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