Daniel C. Reed's research while affiliated with University of California, Santa Barbara and other places

Publications (125)

Article
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Ocean warming has both direct physiological and indirect ecological consequences for marine organisms. Sessile animals may be particularly vulnerable to anomalous warming given constraints in food acquisition and reproduction imposed by sessility. In temperate reef ecosystems, sessile suspension feeding invertebrates provide food for an array of mo...
Article
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Coastal ecosystems play a disproportionately large role in society, and climate change is altering their ecological structure and function, as well as their highly valued goods and services. In the present article, we review the results from decade-scale research on coastal ecosystems shaped by foundation species (e.g., coral reefs, kelp forests, c...
Article
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The conservation benefits of marine reserves are well established but their contribution to adjacent fisheries via spillover is less certain and context‐dependent. Theoretical predictions do not always match empirical evidence from individual reserves, so carefully designed studies are essential for accurately assessing spillover and its contributi...
Article
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Herbivores can reach extraordinary abundances in many ecosystems. When herbivore abundance is high, heavy grazing can severely defoliate primary producers and, in some cases, even drive ecosystem to undergo regime shifts from a high productivity state to a denuded, low productivity state. While the phenomenon of herbivore‐driven regime shifts is we...
Chapter
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Kelp forests are ecologically diverse habitats that provide vast ecosystem goods and services but are threatened by climate and anthropogenic stressors. Laminarian kelps have an alternating biphasic life cycle, and while there is a growing understanding of climate impacts on the macroscopic diploid sporophyte, impacts on the microscopic haploid gam...
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This study examined the capacity of the giant kelp, Macrocystis pyrifera, to exhibit surge uptake as a mechanism to enhance nitrogen assimilation during seasons when nitrate is depleted. Surge uptake of nitrate, ammonium, and urea was assessed in the spring and summer with whole-blade incubation experiments using ¹⁵ N tracers. The incubation experi...
Article
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Surface-canopy forming kelps provide the foundation for ecosystems that are ecologically, culturally, and economically important. However, these kelp forests are naturally dynamic systems that are also threatened by a range of global and local pressures. As a result, there is a need for tools that enable managers to reliably track changes in their...
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Disturbances often disproportionately impact different vegetation layers in forests and other vertically stratified ecosystems, shaping community structure and ecosystem function. However, disturbance‐driven changes may be mediated by environmental conditions that affect habitat quality and species interactions. In a decade‐long field experiment, w...
Article
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Assessing ecosystem integrity by monitoring populations and communities is an important management tool, but is often limited by the immense variety of species and the rarity of many of them. Grouping species by their responses to variation in the environment is one approach to choosing species to serve as effective indicators of community change....
Article
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Ecosystems across the United States are changing in complex and surprising ways. Ongoing demand for critical ecosystem services requires an understanding of the populations and communities in these ecosystems in the future. This paper represents a synthesis effort of the U.S. National Science Foundation‐funded Long‐Term Ecological Research (LTER) n...
Article
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Disturbance and foundation species can both have strong impacts on ecosystem structure and function, but studies of their interacting effects are hindered by the long lifespans and slow growth of most foundation species. Here, we investigated the extent to which foundation species may mediate the impacts of disturbance on ecological communities, us...
Article
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Seasonal or chronic nutrient limitations in the photic zone limit large-scale cultivation of seaweed (macroalgae) in much of the world's oceans, hindering the development of macroalgae as a biofuel feedstock. One possible solution is to supply nutrients using a diel depth-cycling approach, physically moving the macroalgae between deep nutrient-rich...
Article
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Distinguishing between human impacts and natural variation in abundance remains difficult because most species exhibit complex patterns of variation in space and time. When ecological monitoring data are available, a Before‐After‐Control‐Impact (BACI) analysis can control for natural spatial and temporal variation to better identify an impact and e...
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Marine Protected Areas (MPAs) are designed to enhance biodiversity and ecosystem services. Some MPAs are also established to benefit fisheries through increased egg and larval production, or the spillover of mobile juveniles and adults. Whether spillover influences fishery landings depend on the population status and movement patterns of target spe...
Article
Urea is an available and readily used source of nitrogen for giant kelp, Macrocystis pyrifera, but little is known about its potential importance for sustaining growth. Results of kinetic experiments indicate urea uptake saturates at an average maximum rate (Vmax) of 0.73–0.92 μmol N g dw−1 h−1 with a half saturation constant (Ks) of 1.02–1.08 μM....
Article
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The emerging sector of offshore kelp aquaculture represents an opportunity to produce biofuel feedstock to help meet growing energy demand. Giant kelp represents an attractive aquaculture crop due to its rapid growth and production, however precision farming over large scales is required to make this crop economically viable. These demands necessit...
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Coastal marine ecosystems provide critical goods and services to humanity but many are experiencing rapid degradation. The need for effective restoration tools capable of promoting large-scale recovery of coastal ecosystems in the face of intensifying climatic stress has never been greater. We identify four major challenges for more effective imple...
Cover Page
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Sunlight filtering through the canopy of Macrocystis pyrifera, July 2017, Channel Islands National Park, California, USA. In this issue, Lamy et al. (Article e02987; doi:10.1002/ecy.2987) use 18 years of data to show that the stability of the emblematic marine foundation species, the giant kelp M. pyrifera, can benefit the stability of the diverse...
Article
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Sea urchins are voracious herbivores that influence the ecological structure and function of nearshore ecosystems throughout the world. Like many species that produce planktonic larvae, their recruitment is thought to be particularly sensitive to climatic fluctuations that directly or indirectly affect adult reproduction and larval transport and su...
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Foundation species structure communities, promote biodiversity and stabilize ecosystem processes by creating locally stable environmental conditions. Despite their critical importance, the role of foundation species in stabilizing natural communities has seldom been quantified. In theory, the stability of a foundation species should promote communi...
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We conducted a population genetic analysis of the stalked kelp, Pterygophora californica, in the Santa Barbara Channel, California, USA. The results were compared with previous work on the genetic differentiation of giant kelp, Macrocystis pyrifera, in the same region. These two sympatric kelps share many life history and dispersal characteristics,...
Article
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In 2014–2016 the west coast of North America experienced a marine heatwave that was unprecedented in the historical record in terms of its duration and intensity. This event was expected to have a devastating impact on populations of giant kelp, an important coastal foundation species found in cool, nutrient rich waters. To evaluate this expectatio...
Article
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Globally, anthropogenic pressures are reducing the abundances of marine species and altering ecosystems through modification of trophic interactions. Yet, consumer declines also disrupt important bottom‐up processes, like nutrient recycling, which are critical for ecosystem functioning. Consumer‐mediated nutrient dynamics (CND) are now considered a...
Article
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Because natural ecosystems are complex, it is difficult to predict how their variability scales across space and levels of organization. The species‐insurance hypothesis predicts that asynchronous dynamics among species should reduce variability when biomass is aggregated either from local species populations to local multispecies communities, or f...
Article
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Data from five sites of the International Long Term Ecological Research (ILTER) network in the NorthEastern Pacific, Western Arctic Ocean, Northern Baltic Sea, SouthEastern North Sea and in the Western Mediterranean Sea were analyzed by dynamic factor analysis (DFA) to trace common multi-year trends in abundance and composition of phytoplankton, be...
Article
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Disturbances often cause the disproportionate loss of foundation species but understanding how the frequency and severity of disturbance to such organisms influence biological communities remains unresolved. This gap in knowledge exists in part because of the rarity of ecologically meaningful studies capable of disentangling different elements of d...
Article
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The recent spread of the Asian seaweed, Sargassum horneri (Turner) C. Agardh, along the Pacific coast of North America, presents an opportunity to expand our understanding of traits of invasive macroalgae. Here we used surveys to characterize the life history of S. horneri and to quantify traits that promote its spread and persistence, including se...
Preprint
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Sea urchins are voracious herbivores that influence the ecological structure and function of nearshore ecosystems throughout the world. Urchin population growth rates may be particularly sensitive to climate change because adult reproduction and larval development can vary greatly with food availability and temperature, and the transport of their l...
Article
The giant kelp Macrocystis pyrifera forms subtidal forests on shallow reefs in temperate regions of the world. It is one of the fastest‐growing multicellular autotrophs on Earth and its high productivity supports diverse marine food webs. In 2008, we published a method for estimating biomass and net primary production (NPP) of giant kelp along with...
Article
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Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time se...
Article
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Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time se...
Article
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Nitrate concentrations routinely fall below levels required to sustain growth of giant kelp (Macrocystis pyrifera) during summer and autumn in the Santa Barbara Channel, yet growth continues. We found urea to be consistently present at concentrations of 0.48–1.82 μM, accounting for greater than 20% of the dissolved fixed nitrogen pool during summer...
Article
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Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community led open-source database of biodiversity time se...
Article
Foundation species define the ecosystems they live in, but ecologists have often characterized dominant plants as foundational without supporting evidence. Giant kelp has long been considered a marine foundation species due to its complex structure and high productivity; however, there is little quantitative evidence to evaluate this. Here, we appl...
Article
The US and Mexico share a common history in many areas, including language and culture. They face ecological changes due to the increased frequency and severity of droughts and rising energy demands; trends that entail economic costs for both nations and major implications for human well being. We describe an ongoing effort by the Environment Worki...
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Identifying spatial scales of variation in natural communities and the processes driving them is critical for obtaining a predictive understanding of biodiversity. In this study, we focused on diverse communities inhabiting productive kelp forests on shallow subtidal rocky reefs in southern California, USA. We combined long-term community surveys f...
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Photoautotrophs vary the concentration of photosynthetic pigments in response to changing environmental conditions. In the ocean, the chlorophyll a to carbon ratio (Chl:C) has been used as a proxy for the physiological condition of phytoplankton, and there is laboratory evidence that the growth rate of juvenile giant kelp (Macrocystis pyrifera), a...
Chapter
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The coastal forests formed by the giant kelp Macrocystis pyrifera are iconic and primary habitats distributed discontinuously from central Baja California (Mexico) to central California (USA). The giant kelp creates a biogenic habitat that supports high levels of species diversity and productivity in the region, acting as a refuge, nursery and food...
Article
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Global climate change is likely to constrain low latitude range edges across many taxa and habitats. Such is the case for NE Atlantic marine macroalgal forests, important ecosystems whose main structuring species is the annual kelp Saccorhiza polyschides. We coupled ecological niche modelling with simulations of potential dispersal and delayed deve...
Article
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Demographic connectivity is vital to sustaining metapopulations yet often changes dramatically through time due to variation in the production and dispersal of offspring. However, the relative importance of variation in fecundity and dispersal in determining the connectivity and dynamics of metapopulations is poorly understood due to the paucity of...
Article
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Background: Molecular markers are revealing a much more diverse and evolutionarily complex picture of marine biodiversity than previously anticipated. Cryptic and/or endemic marine species are continually being found throughout the world oceans, predominantly in inconspicuous tropical groups but also in larger, canopy-forming taxa from well studied...
Article
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Determining the feasibility of controlling marine invasive algae through removal is critical to developing a strategy to manage their spread and impact. To inform control strategies, we investigated the efficacy and efficiency of removing an invasive seaweed, Sargassum horneri, from rocky reefs in southern California, USA. We tested the efficacy of...
Data
Supplementary Figures 1-5 and Supplementary Tables1-2.
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The desire to use sentinel species as early warning indicators of impending climate change effects on entire ecosystems is attractive, but we need to verify that such approaches have sound biological foundations. A recent large-scale warming event in the North Pacific Ocean of unprecedented magnitude and duration allowed us to evaluate the sentinel...
Article
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Significance Kelp forests support diverse and productive ecological communities throughout temperate and arctic regions worldwide, providing numerous ecosystem services to humans. Literature suggests that kelp forests are increasingly threatened by a variety of human impacts, including climate change, overfishing, and direct harvest. We provide the...
Article
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The turnover of plant biomass largely determines the amount of energy flowing through an ecosystem and understanding the processes that regulate turnover has been of interest to ecologists for decades. Leaf life span theory has proven useful in explaining patterns of leaf turnover in relation to resource availability, but the predictions of this th...
Conference Paper
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Sargassum horneri is a large brown alga native to shallow reefs of eastern Asia. It was first discovered in the eastern Pacific in Long Beach Harbor, California in 2003, and has since spread aggressively throughout southern California, USA, and Baja California, Mexico. Because S. horneri can be locally very abundant (>100 adults m-2) and highly per...
Article
Many ecological processes play out over longer time scales and larger spatial scales than can be studied in a traditional 2-4-year grant cycle. Uncertainties in future funding hinder efforts to implement comprehensive research programs that integrate coupled time series observations of physical variables and ecological responses, manipulative exper...
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Conservation and environmental management are principal countermeasures to the degradation of marine ecosystems and their services. However, in many cases, current practices are insufficient to reverse ecosystem declines. We suggest that restoration ecology, the science underlying the concepts and tools needed to restore ecosystems, must be recogni...
Article
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Sargassum horneri (Turner) C. Agardh, 1820 is a fast growing brown alga native to shallow reefs of eastern Asia. It has spread aggressively throughout southern California, USA, and Baja California, México since it was discovered in the eastern Pacific in 2003 and poses a major threat to the sustainability of native marine ecosystems in this region....
Article
Foundation species create milieus in which ecosystems evolve, altering species abundances and distribution often to a dramatic degree. Although much descriptive work supports their importance, there remains little definitive information on the mechanisms by which foundation species alter their environment. These mechanisms fall into two basic categ...
Article
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At small spatial and temporal scales, genetic differentiation is largely controlled by constraints on gene flow, while genetic diversity across a species' distribution is shaped on longer temporal and spatial scales. We assess the hypothesis that oceanographic transport and other seascape features explain different scales of genetic structure of gi...
Article
We investigated the patterns and controls of dissolved organic carbon (DOC) production by the giant kelp (Macrocystis pyrifera) using data from short-term in situ incubations of entire blades and portions of stipes. These data were incorporated into an empirical model of reef-scale net primary production (NPP) at Mohawk Reef in southern California,...
Article
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Ecological theory predicts that demographic connectivity structures the dynamics of local populations within metapopulation systems, but empirical support has been constrained by major limitations in data and methodology. We tested this prediction for giant kelp Macrocystis pyrifera, a key habitat-forming species in temperate coastal ecosystems wor...
Article
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Coastal marine environments experience a wide range of biotic and abiotic forces that can limit and punctuate the geographical range and abundance of species through time. Determining the relative strengths and nonlinear effects of these processes is vital to understanding the biogeographical structures of species. There has been an ongoing discuss...
Article
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Consumer growth and reproductive capacity are direct functions of diet. Strongylocentrotid sea urchins, the dominant herbivores in California kelp forests, strongly prefer giant kelp (Macrocystis pyrifera), but are highly catholic in their ability to consume other species. The biomass of Macrocystis fluctuates greatly in space and time, and the ext...
Preprint
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Consumer growth and reproductive capacity are direct functions of diet. Strongylocentrotid sea urchins, the dominant herbivores in California kelp forests, strongly prefer giant kelp ( Macrocystis pyrifera ), but are highly catholic in their ability to consume other species. The biomass of Macrocystis fluctuates greatly in space and time and the ex...
Preprint
Consumer growth and reproductive capacity are direct functions of diet. Strongylocentrotid sea urchins, the dominant herbivores in California kelp forests, strongly prefer giant kelp ( Macrocystis pyrifera ), but are highly catholic in their ability to consume other species. The biomass of Macrocystis fluctuates greatly in space and time and the ex...
Article
To determine the potential of giant kelp Macrocystis pyrifera detritus as a food resource for coastal suspension feeders, we quantified the production and size distribution of small particulate (< 1 cm) kelp detritus in relation to water motion, state of kelp blade erosion, and percent cover of the bryozoan Membranipora serrilamella on blades. We e...
Conference Paper
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Biological invasions are difficult to predict in part because environmental conditions under which introduced species proliferate are not well understood. We are investigating environmental correlates of distribution patterns of the invasive seaweed Sargassum horneri, which is currently spreading rapidly throughout southern California. Introduced i...
Article
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San Nicolas Island is surrounded by broad areas of shallow subtidal habitat, characterized by dynamic kelp forest communities that undergo dramatic and abrupt shifts in community composition. Although these reefs are fished, the physical isolation of the island means that they receive less impact from human activities than most reefs in Southern Ca...