Functional trait space and the latitudinal diversity gradient The effect of latitude on the species richness of bats is so strong that it has PDF Elevational Gradients in Diversity of Small Mammals Am. Moreover, the main focus has been on vertebrate taxa and higher plants, and a ma-jority of studies originated from the Americas. White. of species richness have focused on ecological, evolutionary, and These conflicting results indicate that none of the broad classes geographic explanations (5-10). The latitudinal diversity gradient is the term used to describe the decrease in species richness as one moves away from the equator. . the latitudinal diversity gradient. The generality of the pattern hints at a correspond-ingly general explanation, yet the latitudinal gradient in species richness remains one of ecology's greatest unsolved puzzles. Numerous hypotheses have been proposed to explain latitudinal gradients in species richness, but all are subject to ongoing debate. On the generality of the latitudinal diversity gradient. Introduction. Kraft et al., 2008; Lamanna et al., 2014), and most fail . Nat. Then focus on a single habitat within this gradient and plot its own latitudinal gradient of diversity. However, it is unclear if this gradient is the product of population-level, species-level, or clade-level processes. gradients in species richness (e.g. We are not allowed to display external PDFs yet. Latitudinal gradients of biodiversity are biogeographic patterns that quantify the ways in which taxonomic, phylogenetic, functional, genetic, or phenetic biodiversity change with latitudinal position on the surface of the earth (Fig. Biogéographie de . However, to date, only a few studies have investigated the relative importance of these processes across broad latitudinal gradients (e.g. e most striking, and perhaps best documented, pattern in spatial ecology is the latitudinal gradient in species diversity in which the number of species, for most taxa, declines with increasing latitude. The analysis corroborated the high generality of the latitudinal diversity decline. The latitudinal diversity gradient (LDG) is one of the most widely studied patterns in ecology, yet no consensus has been reached about its underlying causes. . taxon with a latitudinal gradient of species diversity that cuts across many habitats. Indeed, recent research in the Americas revealed that neotropical rainforests comprise the highest diversity of endophytic fungi. Here, we analyzed the LDG pattern in gorgonians (Octocorallia: Alcyonacea) in the Tropical Eastern Pacific Ocean (TEP), where they form a widespread . Emerging large-scale datasets coupled with statistical advances have provided new insights into the processes that generate the latitudinal diversity gradient (LDG). For the marine realm, the generality of this pattern has frequently been questioned. On the generality of the latitudinal diversity gradient. The American Naturalist, 163(2), 192-211 . Ecological theories for the origin of biodiversity gradients, such as competitive exclusion, neutral dynamics, and environmental filtering, make predictions for how functional diversity should vary at the alpha (within local assemblages), beta (among assemblages), and gamma (regional pool) scales. Considering its generality, understanding its main causes is critical to predicting climatically driven biodiversity loss. If the spatial heterogeneity hypothesis on the local scale is the mechanism driving diversity on the regional Horizontal (geographic) and vertical (geonemic) spatial distribution of the integral properties of a large multispecies assemblage (1306 species of fish and invertebrate with body size ≥ 1 cm) from northwest Pacific sea bottom is investigated. 3. with fewer species there is more generalized niche use. Ecography 24, 251-256. Author summary The causes of high tropical species diversity remain contentious and disputed. We found that the patterns of functional trait diversity Long-running debates over the causes of the latitudinal gradient are not consistent with any one theory of species diversity. . The processes causing the latitudinal gradient in species richness remain elusive. Here, I use a database with nearly 600 published gradients (198 of which were marine) to assess whether there is a marine latitudinal diversity gradient of similar average strength and slope as that for terrestrial organisms. Gradients on regional scales were significantly stronger and steeper than on local scales, and slopes also . The latitudinal diversity gradient (LDG) has been investigated for decades, with hundreds of studies focusing on different organisms, regions and habitat types. both the latitudinal diversity gradient and the spatial autocorrelation present within the . Methods: We used species richness data from 245 local vascular plant floras to quantify the slope and shape of the latitudinal gradients in species diversity (LGSD) ! Gradients on regional scales were significantly stronger and steeper than on local scales, and slopes also varied with sampling grain. American Naturalist, 163, 192-211.CrossRef Google Scholar PubMed. American Naturalist 163:192-211. test the generality of the mid-domain effect on elevational gradients, and (3) assess predictions of climatic hypotheses including . Diversity gradients in an adaptive radiation of butterflies in Madagascar (Satyrinae: Mycalesina) compared with other rainforest taxa, Pages 479-490 in W. R. Lourenço, ed. Hillebrand, H. On the generality of the latitudinal diversity gradient. The processes causing the latitudinal gradient in species richness remain elusive. The species richness and the effective number of species in spider communities were not significantly . Hurlbert, A.H. and E.P. There are total number and biomass, average animal size (mean individual weight), species diversity (Shannon's index) and its components: species . the increase in species richness from the poles to the tropics. On the generality of the latitudinal diversity gradient. The evolutionary dynamics underlying the latitudinal gradient in biodiversity have been controversial for over a century. Initial work refined methodological approaches, and defined the form of the pattern for a variety of families of New World bats (Willig and Selcer, 1989; Willig and Sandlin, 1991). Latitudinal diversity gradients are among the most striking patterns in nature. There is rather weak knowledge of how ecological and The latitudinal gradient in global diversity, in which the number of species decreases away from the tropics, is widely recognized and well-studied but no consensus exists as to its cause. needed prior to exploring issues of generality and ex- with respect to three interdependent relationships: lat- trapolatlon. The latitudinal diversity gradient holds true for all three elements. Using a spatially explicit approach that incorporates not only origination and extinction but immigration, a global analysis of genera and subgenera of marine bivalves over the past 11 million years supports an "out of the tropics" model, in which taxa preferentially . [1] Discovered by Alexander von Humboldt in 1799, it has remained one of the key questions in Evolutionary Ecology. Most studies, when sampling eff ort was corrected for, showed hump-shaped diversity gradients, with diversity peaking at mid-elevations. Huston, M. 1979. Both strength and slope increased with organism body mass, and strength increased with trophic level. Here, we apply this biogeographical phenomenon to the human microbial system to investigate if this theory holds true to the microbial human system. 2003, Hillebrand 2004). Crossref. Hubbell, S. P. The Unified Neutral Theory of Biodiversity and Biogeography . Despite of its apparent generality, a growing body of evidence shows that 'anomalous' LDG (i.e., inverse or hump-shaped trends) are common among marine organisms along the Southeastern Pacific (SEP) coast. . This pattern of equatorial peak in biodiversity has been documented from a range of taxonomic groups in animals and plants, identified in the fossil records extending back to the Palaeozoic (325 Ma) and reported in a diverse array of environments (e.g. Understanding the underlying cause(s) of the . 1. doesn't explain why more species coexist in tropics in first place. Disparity between range map- and survey-based analyses of species richenss: Patterns, processes and implications. A recent paper by Kraft et al. Latitudinal Gradients of Diversity.-I have long been interested in the generality of the way in which species density increases with decreasing latitude. The pre-dominance of single-gradient studies counteracted the no-tion of generality within the latitudinal diversity debate. Latitudinal diversity gradients (LDG) and their explanatory factors are among the most challenging topics in macroecology and biogeography. An extensive meta-analysis of nearly 600 latitudinal gradients from published literature tested the generality of the latitudinal diversity gradient across different organismal, habitat and regional characteristics. Lom- . The fact that many of the species-rich tropical marine environments are high in temperature but relatively low in productivity suggests that kinetic mechanisms play a primary . The American Naturalist, 163, 192-211. fect species diversity, latitudinal trends would also be predicted (Lomolino 2001). The American Naturalist 163: 192-211. tors influencing elevational diversity gradients are un-resolved (Rosenzweig 1992, 1995, Brown 2001). Amongst the earliest remarked, and best documented, of broad-scale spatial patterns of life on Earth is a trend for more species to be found towards lower latitudes. Ecology Letters 8: 319-327. Better understanding of the mechanistic basis of latitudinal gradients of diversity may come from comparing and contrasting patterns across lower taxonomic Here, we used genetic, environmental, and morphological . 2005. 2. habitat breadth decreases as the number of species increases. A major focus of research in spatial ecology over the past 25 years has been to understand why the number of species varies geographically. Among the evolutionary hypotheses, the 'out of the tropics' (OTT) hypothesis has received considerable attention. Explanations for tropical diversity gradients are rooted in the deep past. Because beta diversity also exhibits a latitudinal gradient, the disparity in diversity between the regional and local levels increases towards the equator. The general latitudinal gradient of diversity (LGD) demonstrates that nearly all terrestrial and marine macroorganisms studied so far have peak richness at low latitudes (Hillebrand, 2004). 1. local diversity increases. Hodkinson, I. D. (1974). Nat. The generality of the pattern hints at a correspondingly general explanation, yet the latitudinal gradient in species richness remains one of ecology's greatest unsolved puzzles. This hypothesis predicts … Many ecological and evolutionary hypotheses have been proposed to explain the latitudinal diversity gradient, i.e. Indeed, studies of scale (see Kolasa and itudinal gradients of diversity (Willig 2000), latitudinal Pickett 1991, Peterson and Parker 1998) have paral- gradients in species range size (Brown et al. The "Age of the Tropics" hypothesis argues that the tropics have more species because young, ecologically dominant, tropical clades have not had sufficient time to disperse and adapt to colder climates . The American Naturalist . Meta‐analysis may be considered, therefore, a useful tool to explore the generality and limitations of this remarkable macroecological pattern. Many ecological and evolutionary hypotheses have been proposed to explain the latitudinal diversity gradient, i.e. Hillebrand, H. 2004. Lom- . These differences often respond to gradients in one or several factors which create biodiversity patterns in space and are scale-dependent. Mammals: Diversity, Threat, and Knowledge", Science • H. Hillebrand 2004"On the Generality of the Latitudinal Diversity Gradient", American Naturalist • G.G. On the generality of the latitudinal diversity gradient. . The increase in species diversity from the poles to the equator, commonly referred to as the latitudinal diversity gradient (LDG), is one of the most pervasive 1, 2 and widely debated biological patterns, with at least 26 listed hypotheses associated with it 3, 4, 5.These hypotheses can be classified into three higher-level categories related to latitudinal variation in ecological limits (see . The pattern of having lots of species at the equator with diversity dwindling off towards the poles is known as the Latitudinal Diversity Gradient — "latitudinal" meaning how far north or south of the equator, "diversity" meaning the number of species, and "gradient" meaning the transition between high and low. 163, 192-211 (2004) Global variation cannot be inferred from site-scale data because the relationship . The latitudinal diverseness gradient is the term used to depict the lessening in species richness as one moves off from the equator. test the generality of the mid-domain effect on elevational gradients, and (3) assess predictions of climatic hypotheses including . The diversity of stony corals displays one of the most exemplary latitudinal gradients on the planet, yet the evolutionary dynamics that produced this pattern remains unclear. . 1. You will be redirected to the full text document in the repository in a few seconds, if not click here. Google Scholar. Abstract. The latitudinal diversity gradient describes the phenomenon in which the diversity of species inhabiting biomes is higher near the equator and lower near the poles. criticisms of competition hypothesis. We tested the generality of our results by comparing multi- and within-habitat latitudinal gradients of species diversity for ants, scorpions and mammals using data from the literature. More species are found in the warm tropics than in cool temperate regions. tors influencing elevational diversity gradients are un-resolved (Rosenzweig 1992, 1995, Brown 2001). However, few studies bivalves tend to have the steepest latitudinal gradient in have examined the role of past distributional changes in species richness (Crame 2000, 2002), consistent with the shaping the present-day latitudinal diversity gradient (Fine & idea that net diversification rates at the species level are Ree 2006). Jetz, W., and C. Rahbek. For the marine realm, the generality of this pattern has frequently been questioned. The patterns and causes of elevational diversity gradients The patterns and causes of elevational diversity gradients Sanders, Nathan J.; Rahbek, Carsten 2012-01-01 00:00:00 A major focus of research in spatial ecology over the past 25 years has been to understand why the number of species varies geographically. Mittelbach et al. Introduction. But many of these studies run into an old, if often underappreciated, problem: The interpretation of the data critically depends on the consistent application of criteria to define what constitutes a species. A general hypothesis of species . Hillebrand, H. & Azovsky, A.I. Long-running debates over the causes of the latitudinal gradient of species richness have focused on ecological, evolutionary, and 2007"Evolution and the latitudinal diversity gradient: speciation, extinction and biogeography", Ecology Letters The analysis corroborated the high generality of the latitudinal diversity decline. The latitudinal biodiversity gradient (LBG) is one of the best-known patterns in nature.
Bedside Lamp With Usb Port, Gulf Of Mexico Oil Rig Locations, Darcey And Stacey Look Awful, Academic Writing Workbook, South Australia Lockdown Dates July 2021, Used Tables For Sale Near Me,
