Michael D. Weiser

University of Oklahoma | ou · Department of Biology

Aim: To test the latitudinal gradient in plant species diversity for self-similarity across taxonomic scales and amongst taxa. Location: North America. 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) across all plant species as well...

Aim Relationships between range size and species richness are contentious, yet they are key to testing the various hypotheses that attempt to explain latitudinal diversity gradients. Our goal is to utilize the largest data set yet compiled for New World woody plant biogeography to describe and assess these relationships between species richness and...

Significance The diversity of living things generally peaks in the tropics and declines toward the poles. This “latitudinal gradient” is Earth’s most prevalent biogeographic pattern, but biologists do not agree about its cause. Here, we use geographic and evolutionary data for over 12,500 species of woody flowering plants to test the “tropical cons...

Tropical forest canopies house most of the globe's diversity, yet little is known about global patterns and drivers of canopy diversity. Here, we present models of ant species density, using climate, abundance and habitat (i.e. canopy versus litter) as predictors. Ant species density is positively associated with temperature and precipitation, and...

1. The size–grain hypothesis maintains that as terrestrial walking organisms decrease in size, their environment becomes less planar and more rugose. The benefits of long legs (efficient, speedy movement over a planar environment) may thus decrease with smaller body size, while the costs (larger cross-sectional area limiting access to the interstit...

Despite growing concerns over the health of global invertebrate diversity, terrestrial invertebrate monitoring efforts remain poorly geographically distributed. Machine-assisted classification has been proposed as a potential solution to quickly gather large amounts of data; however, previous studies have often used unrealistic or idealized dataset...

Activity Density (AD, the rate that animals collectively move through their environment) emerges as the product of a taxon’s local abundance and its velocity. We analyze drivers of seasonal AD using 47 localities from the National Ecological Observatory Network (NEON) both to better understand variation in ecosystem rates like pollination and seed...

Invertebrates constitute the majority of animal species and are critical for ecosystem functioning and services. Nonetheless, global invertebrate biodiversity patterns and their congruences with vertebrates remain largely unknown. We resolve the first high-resolution (~20-km) global diversity map for a major invertebrate clade, ants, using biodiver...

Biodiversity monitoring is imperative for understanding how changing climate may impact the distributions of taxa from single species to the spatial distribution of biological diversity. Large‐scale and cross‐taxa biodiversity monitoring also allows an empirical understanding of biogeographic patterns across taxa. One such pattern, where in taxonom...

Biologists have long been fascinated by the processes that give rise to pheno-typic complexity of organisms, yet whether there exist geographical hotspots of phenotypic complexity remains poorly explored. Phenotypic complexity can be readily observed in ant colonies, which are superorganisms with morphologically differentiated queen and worker cast...

Biologists have long been fascinated by the processes that give rise to phenotypic complexity of organisms, yet whether there exist geographical hotspots of phenotypic complexity remains poorly explored. Phenotypic complexity can be readily observed in ant colonies, which are superorganisms with morphologically differentiated queen and worker caste...

Ecologists search for rules by which traits dictate the abundance and distribution of species. Here we search for rules that apply across three common taxa of litter invertebrates in six North American forests from Panama to Oregon. We use image analysis to quantify the abundance and body size distributions of mites, springtails, and spiders in 21‐...

This protocol is the complete methods used to extract abundance, morphology and color data from samples of invertebrates. We developed this protocol specifically to measure invertebrate by-catch from pitfall traps collected by the National Ecological Observatory Network (NEON), but these methods could be extended to any invertebrate samples. These...

Activity density (AD)-the rate that an individual taxon or its biomass moves through the environment-is used both to monitor communities and quantify the potential for ecosystem work. The Abundance Velocity Hypothesis posited that AD increases with Aboveground Net Primary Productivity (ANPP) and is a unimodal function of temperature. Here we show t...

Despite growing concerns over the health of global invertebrate diversity, terrestrial invertebrate monitoring efforts remain poorly geographically distributed. Machine-assisted classification has been proposed as a potential solution to quickly gather large amounts of data; however, previous studies have often used unrealistic or idealized dataset...

Across the globe, temperatures are predicted to increase with consequences for many taxo-nomic groups. Arthropods are particularly at risk as temperature imposes physiological constraints on growth, survival, and reproduction. Given that arthropods may be disproportionately affected in a warmer climate-the question becomes which taxa are vulnerable...

This protocol is the complete methods used to extract abundance, morphology and color data from samples of invertebrates. We developed this protocol specifically to measure invertebrate by-catch from pitfall traps collected by the National Ecological Observatory Network (NEON), but these methods could be extended to any invertebrate samples. These...

• Insect populations are changing rapidly, and monitoring these changes is essential for understanding the causes and consequences of such shifts. However, large‐scale insect identification projects are time‐consuming and expensive when done solely by human identifiers. Machine learning offers a possible solution to help collect insect data quickly...

Aim In ectotherms, gradients of environmental temperature can regulate metabolism, development and ultimately fitness. The thermal adaptation hypothesis assumes that thermoregulation is costly and predicts that more thermally variable environments favour organisms with wider thermal ranges and thermal limits (i.e., critical thermal minima and maxim...

Rather than simple accumulation of individual populations, microorganisms in natural ecosystems form complex ecological networks that are critical to maintain ecosystem functions and services. Although various studies have examined the patterns of microbial community diversity and composition across spatial gradients, whether microbial co-occurrenc...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

In an era of rapid climate change, and with it concern over insect declines, we used two theories to predict 20‐year changes in 34 North American ant communities. The ecosystems, from deserts to hardwood forests, were first surveyed in the 1990s. When resurveyed in 2016‐2017 they averaged 1°C warmer with 200 gC/m2/y higher plant productivity. Ant c...

Trait-based ecology claims to offer a mechanistic approach for explaining the drivers that structure biological diversity and predicting the responses of species, trophic interactions and ecosystems to environmental change. However, support for this claim is lacking across broad taxonomic groups. A framework for defining ecosystem processes in term...

The metabolic theory of ecology assumes that rates of selection and adaptation for organisms are functions of temperature. Niche theory predicts that strong selection pressure should simplify assemblages as species are extirpated and taxa pre-adapted for the new environment thrive. Here, we use closed mesocosms to test the prediction that higher te...

The latitudinal diversity gradient—the tendency for more species to occur toward the equator—is the dominant pattern of life on Earth, yet the mechanisms responsible for it remain largely unexplained. Recently, the analysis of global data has led to advances in understanding, but these advances have been mostly limited to vertebrates and trees and...

Micro-organisms harbouring the nosZ gene convert N2O to N2 and play a critical role in reducing global N2O emissions. As higher denitrifier diversity can result in higher denitrification rates, here we aimed to understand the diversity, composition and spatial structure of N2O-reducing microbial assemblages in forest soils across a large latitudina...

Nature Communications 8 : Article number: 15583 10.1038/ncomms15583 ( 2017 ); Published: 6 June 2017 We greatly appreciate Tedersoo’s interest in our recent publication concerning temperature effects on continental scale diversity of microbial communities in forest soils .

Humans are both fertilizing the world and depleting its soils, decreasing the diversity of aquatic ecosystems and terrestrial plants in the process. We know less about how nutrients shape the abundance and diversity of the prokaryotes, fungi, and invertebrates of Earth's soils. Here we explore this question in the soils of a Panama forest subject t...

Aim: Mapping the distribution and diversity of plant functional traits is critical for projecting future changes to vegetation under global change. Maps of plant functional traits, however, are scarce due very sparse global trait data matrices. A potential solution to this data limitation is to utilize the known levels of phylogenetic signal in tra...

Climate regulation services from forests are an important leverage in global-change mitigation treaties. Like most ecosystem services, climate regulation is the product of various ecological phenomena with unique spatial features. Elucidating which abiotic and biotic factors relate to spatial patterns of climate regulation services advances our und...

What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of mo...

The global distribution patterns of most vertebrate groups and several plant groups have been described and analyzed over the past few years, a development facilitated by the compilation of important databases. Similar efforts are needed for large insect groups that constitute the majority of global biodiversity. As a result of this lack of informa...

The Abundance-Adaptation Hypothesis argues that taxa with more individuals and faster generation times will have more evolutionary “experiments” allowing expansion into, and diversification within, novel habitats. Thus, as older taxa have produced more individuals over time, and smaller taxa have higher population sizes and faster generation times,...

Soil organisms are important in mediating nutrient availability to independent ecosystem for maintaining environment balance. Microbial communities on artificial islands are depauperate due to the influence of biogeographic processes and interference. Thus, there may be an advantage to island ecosystem that explor soil microbial function differenti...

Nitrogen and phosphorus frequently limit terrestrial plant production, but have a mixed record in regulating the abundance of terrestrial invertebrates. We contrasted four ways that Na could interact with an NP fertilizer to shape the plants and invertebrates of an inland prairie. We applied NP and Na to m(2) plots in a factorial design. Abovegroun...

In recent years the focus in ecology has shifted from species to a greater emphasis on functional traits. In tandem with this shift, a number of trait databases have been developed covering a range of taxa. Here, we introduce the GlobalAnts database. Globally, ants are dominant, diverse and provide a range of ecosystem functions. The database repre...

Nature Plants 2 , 16129 (2016); published 22 August 2016; corrected 26 August 2016. In the version of this Article originally published, the affiliation for Nate G. McDowell was incorrect. This has now been corrected.

Leaf thermoregulation has been documented in a handful of studies, but the generality and origins of this pattern are unclear. We suggest that leaf thermoregulation is widespread in both space and time, and originates from the optimization of leaf traits to maximize leaf carbon gain across and within variable environments. Here we use global data f...

Climate warming is increasingly leading to marked changes in plant and animal biodiversity, but it remains unclear how temperatures affect microbial biodiversity, particularly in terrestrial soils. Here we show that, in accordance with metabolic theory of ecology, taxonomic and phylogenetic diversity of soil bacteria, fungi and nitrogen fixers are...

Supplementary Figures 1-3 and Supplementary Tables 1-9

Soil diazotrophs play important roles in ecosystem functioning by converting atmospheric N2 into biologically available ammonium. However, the diversity and distribution of soil diazotrophic communities in different forests and whether they follow biogeographic patterns similar to macro-organisms still remain unclear. By sequencing nifH gene amplic...

The relationship between large-scale gradients in species richness and functional diversity provides important information regarding the mechanisms driving patterns of biodiversity. A classic hypothesis in ecology is that strong interspecific interactions should result in an increase in the functional volume of assemblages as the species richness i...

Building a more predictive trait-based ecology requires mechanistic theory based on first principles. We present a general theoretical approach to link traits and climate. We use plant leaves to show how energy budgets (i) provide a foundation for understanding thermoregulation, (ii) explain mechanisms driving trait variation across environmental g...

The relationship between tree height and diameter is fundamental in determining community and ecosystem structure as well as estimates of biomass and carbon storage. Yet our understanding of how tree allometry relates to climate and whole organismal function is limited. We used the Forest Inventory and Analysis National Program database to determin...

Adaptive radiations are of particular interest owing to what they reveal about the ecological and evolutionary regulation of biodiversity. This applies to localized island radiations such as Darwin's finches, and also to rapid radiations occurring on a global scale. Here we analyse the macroevolution and macroecology of Pheidole, a famously hyperdi...

Knowledge of the biogeographic distribution of ants is central to our understanding of ant ecology, evolution, taxonomy and conservation. Here, we introduce a novel global biogeographic database for ant genera and an associated website with maps showing the known distribution of all extant ant genera. We use this database to consider knowledge of t...

Background/Question/Methods Understanding the responses and the underlying mechanisms of ecological communities to environmental changes is a central issue in ecology. Mean temperature rising on Earth surface represents a pervasive environmental change that is predicted to alter global biodiversity, yet our understanding of the emergent biodivers...

Background/Question/Methods Although the latitudinal of biodiversity pattern is well-documented and intensively studied in plant and animal ecology, it is not clear whether microbes also exhibit similar latitudinal diversity gradients. Due to their small size, extreme abundance, high dispersal capabilities, and low extinction rates, some have hyp...

Background/Question/Methods The processes causing the latitudinal gradient in species richness remain elusive. 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 different spatial scales and across bro...

Background/Question/Methods Climate is thought to drive variation in plant growth rates via direct effects on the kinetics of photosynthesis and respiration. However, recent studies have shown that plant growth rates converge across climate gradients to a common scaling relationship with plant functional traits and plant biomass, suggesting that...

Background/Question/Methods Nitrous oxide (N2O) is emitted by bacteria in soils and oceans as a major greenhouse gas. It also regulates stratospheric ozone in Earth's atmosphere. Microorganisms harboring the nosZ gene encoding N2O reductase can reduce N2O to N2, thus removing N2O from the atmosphere. However, little is known about the distributio...

A fundamental question in ecology is how are species added to the phenotypic or functional trait space when one moves from a species poor to species rich assemblage. Specifically, the functional volume of an assemblage can expand and/or be packed more tightly to accommodate an increasing number of species. Quantifying the packing and filling of tra...

AimWe aimed to quantify the relative contributions of trait-based selection and the flow of individuals across space created by differences in species abundance, i.e. mass effects, in determining local-scale species relative abundance (SRA) at 0.07 ha, 1° grid cell and subregion grains.LocationThe eastern USA.Methods We coupled a maximum entropy mo...

A chemical defense helps an invasive ant species to outcompete an earlier invader that originates from the same native region.

Formicidae) is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how h...

Background/Question/Methods Temperature and precipitation are considered primary drivers of variation in plant growth rate. However, recent studies suggest that much of this variation might instead reflect variation in growing season length, plant size, and/or local adaptation or acclimation of plant functional traits. We assessed these hypothese...