Sally E. Koerner

ORCID: https://orcid.org/0000-0001-6403-7513

Sally Koerner is a community ecologist focused on understanding the drivers of biodiversity and how global change is altering those dynamics. She focuses primarily on grass dominated systems and uses a mixture of experimental manipulations, observational studies, and meta-analyses.

There are 50 included publications by Sally E. Koerner :

TitleDateViewsBrief Description
Ambient changes exceed treatment effects on plant species abundance in global change experiments 2018 191 The responses of species to environmental changes will determine future community composition and ecosystem function. Many syntheses of global change experiments examine the magnitude of treatment effect sizes, but we lack an understanding of how pla...
Asymmetric responses of primary productivity to climate extremes: A synthesis of grassland precipitation manipulation experiments 2017 271 Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the futur...
Asynchrony among local communities stabilizes ecosystem function of metacommunities 2017 124 Temporal stability of ecosystem functioning increases the predictability and reliability of ecosystem services, and understanding the drivers of stability across spatial scales is important for land management and policy decisions. We used species-le...
Change in dominance determines herbivore effects on plant biodiversity 2018 773 Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores en...
Changes in plant community composition, not diversity, during a decade of nitrogen and phosphorus additions drive above-ground productivity in a tallgrass prairie 2014 265 1. Nutrient additions typically increase terrestrial ecosystem productivity, reduce plant diversity and alter plant community composition; however, the effects of P additions and interactions between N and P are understudied. 2. We added both N (10 g...
Characterizing differences in precipitation regimes of extreme wet and dry years: Implications for climate change experiments 2015 296 Climate change is intensifying the hydrologic cycle and is expected to increase the frequency of extreme wet and dry years. Beyond precipitation amount, extreme wet and dry years may differ in other ways, such as the number of precipitation events, e...
A comprehensive approach to analyzing community dynamics using rank abundance curves 2019 1296 Univariate and multivariate methods are commonly used to explore the spatial and temporal dynamics of ecological communities, but each has limitations, including oversimplification or abstraction of communities. Rank abundance curves (RACs) potential...
Critical climate periods for grassland productivity on China’s Loess Plateau 2017 231 Strong correlations between aboveground net primary productivity (ANPP) of grasslands and mean annual temperature or precipitation have been widely reported across regional or continental scales; however, inter-annual variation in these climate facto...
Deadwood stocks increase with selective logging and large tree frequency in Gabon 2017 131 Deadwood is a major component of aboveground biomass (AGB) in tropical forests and is important as habitat and for nutrient cycling and carbon storage. With deforestation and degradation taking place throughout the tropics, improved understanding of ...
Determinants of community compositional change are equally affected by global change 2021 53 Global change is impacting plant community composition, but the mechanisms underlying these changes are unclear. Using a dataset of 58 global change experiments, we tested the five fundamental mechanisms of community change: changes in evenness and r...
Do trade-offs govern plant species’ responses to different global change treatments? 2021 81 Plants are subject to trade-offs among growth strategies such that adaptations for optimal growthin one condition can preclude optimal growth in another. Thus, we predicted that a plant speciesthat responds positively to one global change treatment w...
Droughts and Downpours: Resolving the disconnect between rainfall manipulation experiments and terrestrial ecosystem models 2014 1326 The biological responses to precipitation within the terrestrial components of Earth system models, or land surface models (LSMs), are mechanistically simple and poorly constrained, leaving projections of terrestrial ecosystem functioning and feedbac...
The ecological consequences of forest elephant declines for Afrotropical forests 2018 295 Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas of elephant-free tropical forest. Elephants are ecological engineers that create and maintain forest habitat; thus, ...
Fire frequency drives habitat selection by a diverse herbivore guild impacting top-down control of plant communities in an African savanna 2016 171 In areas with diverse herbivore communities such as African savannas, the frequency of disturbance by fire may alter the top–down role of different herbivore species on plant community dynamics. In a seven year experiment in the Kruger National Park,...
Forest structure determines large liana abundance and distribution in Gabon 2017 254 Aim: Lianas are an important component of forest structure in the tropics, accounting for up to 45% of total stems. Mounting evidence that tropical forests are undergoing structural changes, with a growing abundance of lianas reducing forest carbon s...
A framework for quantifying the magnitude and variability of community responses to global change drivers 2015 295 A major challenge in global change ecology is to predict the trajectory and magnitude of community change in response to global change drivers (GCDs). Here, we present a new framework that not only increases the predictive power of individual studies...
Functional diversity response to geographic and experimental precipitation gradients varies with plant community type 2021 729 1.Precipitation is a primary determinant of plant community structure in drylands. However, the empirical evidence and predictions are lacking for how plant functional diversity in desert and steppe communities respond to altered precipitation regime...
General destabilizing effects of eutrophication on grassland productivity at multiple spatial scales 2020 60 Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relations...
Global change effects on plant communities are magnified by time and the number of global change factors imposed 2019 184 Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem t...
Heatwave implications for the future of longleaf pine savanna understory restoration 2021 365 The longleaf pine (LLP) savanna ecosystem once covered ~ 92 million acres of the Southeast USA,but due to anthropogenic activities such as logging and fire suppression, only 3% of its oncewidespread historic range remains. While many restoration effo...
Herbivore size matters for productivity-richness relationships in African savannas 2017 160 1.Productivity and herbivory often interact to shape plant community composition and species richness with levels of production mediating the impact of herbivory. However, differences in herbivore traits such as size, feeding guild and dietary requir...
Hunting induced defaunation gradient in a Gabonese tropical forest 2017 203 1.Anthropocene defaunation is the global phenomenon of human-induced animal biodiversity loss. Understanding the patterns and process of defaunation is critical to predict outcomes for wildlife populations and cascading consequences for ecosystem fun...
Improving collaborations between empiricists and modelers to advance grassland community dynamics in ecosystem models 2021 78 Climate change, increasing atmospheric CO2, and land use change have altered biogeochemical and hydrologic cycles world-wide, with grassland systems being particularly vulnerable to resulting vegetation shifts (Komatsu et al., 2019). Therefore, incor...
Interactive effects of grazing, drought, and fire on grassland plant communities in North America and South Africa 2014 1284 Grazing, fire, and climate shape mesic grassland communities. With global change altering all three factors, understanding how grasslands respond to changes in these combined drivers may aid in projecting future changes in grassland ecosystems. We ma...
Invasibility of a mesic grassland depends on the time-scale of fluctuating resources 2015 716 1. Global change is increasing the frequency and magnitude of resource fluctuations (pulses) at multiple time-scales. According to the fluctuating resource availability hypothesis (FRAH), susceptibility of an ecosystem to invasion (i.e. invasibility)...
Loss of a single large grazer impacts savanna grassland plant communities similarly in North America and South Africa 2014 204 Large herbivore grazing is a widespread disturbance in mesic savanna grasslands which increases herbaceous plant community richness and diversity. However, humans are modifying the impacts of grazing on these ecosystems by removing grazers. A more ge...
Making sense of multivariate community responses in global change experiments 2022 82 Ecological communities are being impacted by global change worldwide. Experiments are apowerful tool to understand how global change will impact communities by comparing controland treatment replicates. Communities consist of multiple species, and th...
Mass ratio effect underlie ecosystem responses to environmental change. Change in dominance drives ecosystem response to global environmental change 2020 143 1.Random species loss has been shown experimentally to reduce ecosystem function, sometimes more than other anthropogenic environmental changes. Yet, controversy surrounds the importance of this finding for natural systems where species loss is non-r...
Multiple global change drivers show independent, not interactive effects: a long-term case study in tallgrass prairie 2022 166 Ecosystems are faced with an onslaught of co-occurring global change drivers. While frequently studied independently, the effects of multiple global change drivers have the potential to be additive, antagonistic, or synergistic. Global warming, for e...
Nutrient additions cause divergence of tallgrass prairie plant communities resulting in loss of ecosystem stability 2016 750 1.Nitrogen (N) deposition and phosphorus (P) deposition due to pollution and land-use change are dramatically altering biogeochemical cycles. These altered nutrient inputs affect plant communities by generally increasing dominance and reducing divers...
Plant community response to loss of large herbivores differs between North American and South African savanna grasslands 2014 775 Herbivory and fire shape plant community structure in grass-dominated ecosystems, but these disturbance regimes are being altered around the world. To assess the consequences of such alterations, we excluded large herbivores for seven years from mesi...
Poaching empties critical Central African wilderness of forest elephants 2017 170 Elephant populations are in peril everywhere, but forest elephants in Central Africa have sustained alarming losses in the last decade [1]. Large, remote protected areas are thought to best safeguard forest elephants by supporting large populations b...
Rainfall variability has minimal effects on grassland recovery from repeated grazing 2013 979 Question: Mesic grasslands experience a complex disturbance regime including frequent fire, grazing by large ungulates and strong inter-annual climate variability. As a result of climate change, growing season precipitation regimes are predicted to b...
Rapid recovery of ecosystem function following extreme drought in a South African savanna 2020 508 Climatic extremes, such as severe drought, are expected to increase in frequency and magnitude with climate change. Thus, identifying mechanisms of resilience is critical to predicting the vulnerability of ecosystems. An exceptional drought (
Reintroducing bison results in long-running and resilient increases in grassland diversity 2022 107 The widespread extirpation of megafauna may have destabilized ecosystems and alteredbiodiversity globally. Most megafauna extinctions occurred before the modern record, leaving itunclear how their loss impacts current biodiversity. We report the long...
Responses to fire differ between South African and North American grassland communities 2013 234 Question: Does fire frequency affect mesic grassland plant community structure and composition similarly in North America and South Africa? Location: Konza Prairie Biological Station (KNZ), Kansas, USA, and Ukulinga Research Farm (URF), KwaZulu-Natal...
Richness, not evenness, varies across water availability gradients in grassy biomes on five continents 2022 33 We sought to understand the role that water availability (expressed as an aridity index) plays in determining regional and global patterns of richness and evenness, and in turn how these water availability–diversity relationships may result in differ...
Serengeti: People as Part of Ecology [book review] 2009 53 The thought of the Serengeti calls forth images of endless plains, broken only by the occasional Acacia or the large migratory herd of wildebeest. This land captures the imagination, and those who have seen the vast expanse and the unending abundance...
Shared drivers but divergent ecological responses: Insights from long-term experiments in savanna grasslands 2016 236 Fire and grazing, key determinants of structure and function of savanna grasslands worldwide, have been extensively altered by humans. We used existing long-term manipulations of fire and grazing in North American and South African mesic savanna gras...
Small-scale patch structure in North American and South African grasslands responds differently to fire and grazing 2013 839 Fire and grazing significantly impact small-scale patch structure and dynamics in savanna grasslands. We assessed small-scale grass-forb associations in long-term fire and grazing experiments in North America (NA) and Southern Africa (SA). Transects ...
Soil microbial respiration rate and temperature sensitivity along a north-south forest transect in eastern China: Patterns and influencing factors 2016 194 Soil organic matter is one of the most important carbon (C) pools in terrestrial ecosystems, and future warming from climate change will likely alter soil C storage via temperature effects on microbial respiration. In this study, we collected forest ...
Stability of tallgrass prairie during a 19-year increase in growing season precipitation 2012 135 1. Precipitation is considered to be a key driver of ecosystem processes in mesic grasslands, and climate models predict changes in the amount and intensity of precipitation under future global change scenarios. Although most experimental rainfall st...
Temporal heterogeneity increases with spatial heterogeneity in ecological communities 2018 226 Heterogeneity is increasingly recognized as a foundational characteristic of ecological systems. Under global change, understanding temporal community heterogeneity is necessary for predicting the stability of ecosystem functions and services. Indeed...
Temporal variability in production is not consistently affected by global change drivers across herbaceous-dominated ecosystems 2020 79 Understanding how global change drivers (GCDs) affect aboveground net primary production (ANPP) through time is essential to predicting the reliability and maintenance of ecosystem function and services in the future. While GCDs, such as drought, war...
Too wet for frogs: Changes in a tropical leaf litter frog community coincide with La Nina 2015 206 Extreme climatic events such as the El Niño Southern Oscillation profoundly affect many plants and animals, including amphibians, which are strongly negatively affected by drought conditions. How amphibians respond to exceptionally high precipitation...
Toward a better integration of biological data from precipitation manipulation experiments into Earth system models 2014 69 The biological responses to precipitation within the terrestrial components of Earth system models, or land surface models (LSMs), are mechanistically simple and poorly constrained, leaving projections of terrestrial ecosystem functioning and feedbac...
Understory dynamics in North Carolina longleaf pine savannas: Biodiversity, dominance, and biomass 2022 383 Questions Restoration of ecosystems is complex, with multiple targets that can work in concert orconflict with each other, such as biodiversity, species dominance and biomass. When properlymanaged, longleaf pine (LLP) savannas are among the most biol...
The utilization of remote sensing and modeling: savannas from a distance [book review] 2011 68 With the ongoing uncertainty of climate change, there is a need to better understand long-term vegetation dynamics. The greater availability of spatial data from remote sensing presents a perfect opportunity to improve spatial process-based models wh...
Vertebrate community composition and diversity declines along a defaunation gradient radiating from rural villages in Gabon 2017 461 1.Anthropocene defaunation is the global phenomenon of human-induced animal biodiversity loss. Understanding the patterns and process of defaunation is critical to predict outcomes for wildlife populations and cascading consequences for ecosystem fun...
Wanted: New allometric equations for large lianas and African lianas 2016 173 Liana abundance appears to be increasing, possibly to the detriment of trees, but methods for measuring liana biomass are undependable. We show that five commonly used allometric equations produce disparate results and discuss two large information g...