29 Works

Increased frequency of extreme precipitation events in the North Atlantic during the PETM: Observations and theory

William Rush
Climate model simulations of the PETM (Paleocene-Eocene Thermal Maximum) warming have mainly focused on replicating the global thermal response through greenhouse forcing, i.e. CO2, at levels compatible with observations. Comparatively less effort has gone into assessing the skill of models to replicate the response of the hydrologic cycle to the warming, particularly on regional scales. Here we have assembled proxy records of regional precipitation, focusing on the Mid-Atlantic Coasts of North America (New Jersey) and...

Ancient horse genomes reveal the timing and extent of dispersals across the Bering Land Bridge

Alisa Vershinina, Peter Heintzman, Duane Froese, Grant Zazula, Molly Cassatt-Johnstone, Love Dalén, Clio Der Sarkissian, Shelby Dunn, Luca Ermini, Cristina Gamba, Pamela Groves, Joshua Kapp, Daniel Mann, Andaine Seguin-Orlando, John Southon, Mathias Stiller, Matthew Wooller, Gennady Baryshnikov, Dmitry Gimranov, Eric Scott, Elizabeth Hall, Susan Hewitson, Irina Kirillova, Pavel Kosintsev, Fedor Shidlovsky … & Beth Shapiro
The Bering Land Bridge (BLB) last connected Eurasia and North America during the Pleistocene. Although the BLB would have enabled transfers of terrestrial biota in both directions, it also acted as an ecological filter whose permeability varied considerably over time. Here we explore the possible impacts of this ecological corridor on genetic diversity within, and connectivity among, populations of a once wide-ranging group, the caballine horses (Equus spp.). Using a panel of 187 mitochondrial and...

Data from: Local tropical forest restoration strategies affect tree recruitment more strongly than does landscape forest cover

Karen D. Holl, John Leighton Reid, José Miguel Chaves-Fallas, Federico Oviedo-Brenes & Rakan A. Zahawi
Developing restoration strategies that accelerate natural successional processes and are resource‐efficient is critical to facilitating tropical forest recovery across millions of hectares of deforested lands in the tropics. We compared tree recruitment after a decade in three restoration treatments (natural regeneration, applied nucleation/island tree planting and plantation) and nearby reference forest in the premontane rain forest zone in southern Costa Rica. The study was replicated at 13 sites with a range of surrounding forest cover,...

Data from: Factors explaining variability in woody above-ground biomass accumulation in restored tropical forest

Karen D. Holl & Rakan A. Zahawi
Secondary forests comprise an increasing area of the tropics and play an important role in global carbon cycling. We compare above-ground biomass accumulation of both planted and naturally regenerating trees, as well as C in the top soil layer, in three restoration treatments replicated at 14, six to eight year old restoration sites in southern Costa Rica. Restoration strategies include: control (no planting), planting tree islands, and conventional, mixed-species tree plantations. We evaluate the importance...

Data from: A fast and efficient single-stranded genomic library preparation method optimized for ancient DNA

Joshua Kapp, Richard Green & Beth Shapiro
We present a protocol to prepare extracted DNA for sequencing on the Illumina sequencing platform that has been optimized for ancient and degraded DNA. Our approach, the Santa Cruz Reaction or SCR, uses directional splinted ligation of Illumina’s P5 and P7 adapters to convert natively single-stranded DNA and heat denatured double-stranded DNA into sequencing libraries in a single enzymatic reaction. To demonstrate its efficacy in converting degraded DNA molecules, we prepare five ancient DNA extracts...

Variation in purple sea urchin (Strongylocentrotus purpuratus) morphological traits in relation to resource availability

Joshua Smith & Sabrina Garcia
Flexible resource investment is a risk-sensitive reproductive strategy where individuals trade resources spent on reproduction for basic metabolic maintenance and survival. This study examined morphological variation in herbivorous sea urchin grazers across a mosaic landscape of macroalgae-dominated habitats interspersed with patches of sea urchin barrens to determine whether sea urchins shift energy allocation in response to food limitation. Extensive underwater surveys of habitat attributes (e.g., sea urchin density, algae cover) were paired with detailed laboratory...

Microhabitats associated with solar energy development alter demography of two desert annuals

Karen Tanner, Kara Moore-O'Leary, Ingrid Parker, Bruce Pavlik, Sophia Haji & Rebecca Hernandez
Political and economic initiatives intended to increase energy production while reducing carbon emissions are driving demand for solar energy. Consequently, desert regions are now targeted for development of large-scale photovoltaic solar energy facilities. Where vegetation communities are left intact or restored within facilities, ground-mounted infrastructure may have negative impacts on desert-adapted plants because it creates novel rainfall runoff and shade conditions. We used experimental solar arrays in the Mojave Desert to test how these altered...

Data from: Effects of dispersal‐ and niche‐based factors on tree recruitment in tropical wet forest restoration

Leland K. Werden, Karen D. Holl, Juan Abel Rosales, Janelle M. Sylvester & Rakan A. Zahawi
Both dispersal‐ and niche‐based factors can impose major barriers on tree establishment. Our understanding of how these factors interact to determine recruitment rates is based primarily on findings from mature tropical forests, despite the fact that a majority of tropical forests are now secondary. Consequently, factors influencing seed limitation and the seed‐to‐seedling transition (STS) in disturbed landscapes, and how those factors shift during succession, are not well understood. We used a 3.5‐yr record of seed...

Bird Frugivore Abundance data from: Applied nucleation facilitates tropical forest recovery

Karen D. Holl, J. Leighton Reid, Rebecca J. Cole, Federico Oviedo‐Brenes, Juan A. Rosales & Rakan A. Zahawi
Applied nucleation, mostly based upon planting tree islands, has been proposed as a cost‐effective strategy to meet ambitious global forest and landscape restoration targets. We review results from a 15‐year study, replicated at 15 sites in southern Costa Rica, that compares applied nucleation to natural regeneration and mixed‐species tree plantations as strategies to restore tropical forest. We have collected data on planted tree survival and growth, woody vegetation recruitment and structure, seed rain, litterfall, epiphytes,...

Data from: Seed dispersal limitations shift over time in tropical forest restoration

J. Leighton Reid, Karen D. Holl & Rakan A. Zahawi
Past studies have shown that tropical forest regeneration on degraded farmlands is initially limited by lack of seed dispersal, but few studies have tracked changes in abundance and composition of seed rain past the first few years after land abandonment. We measured seed rain for 12 months in 10 6–9‐year‐old restoration sites and five mature, reference forests in southern Costa Rica in order to learn (1) if seed rain limitation persists past the first few...

Data from: Reduced aboveground tree growth associated with higher arbuscular mycorrhizal fungal diversity in tropical forest restoration

Ellen K. Holste, Karen D. Holl, Rakan A. Zahawi & Richard K. Kobe
Establishing diverse mycorrhizal fungal communities is considered important for forest recovery, yet mycorrhizae may have complex effects on tree growth depending on the composition of fungal species present. In an effort to understand the role of mycorrhizal fungi community in forest restoration in southern Costa Rica, we sampled the arbuscular mycorrhizal fungal (AMF) community across eight sites that were planted with the same species (Inga edulis, Erythrina poeppigiana, Terminalia amazonia, and Vochysia guatemalensis) but varied...

Data from: Litterfall and nutrient dynamics shift in tropical forest restoration sites after a decade of recovery

Karen D. Holl, Fernando Casanoves, Rakan A. Zahawi, Danielle Celentano, Diego Delgado & Oscar Lanuza
Multi‐year studies comparing changes in litterfall biomass and nutrient inputs in sites under different restoration practices are lacking. We evaluated litterfall dynamics and nutrient inputs at 5 yr and after a decade of recovery in four treatments (natural regeneration—no planting, plantation—entire area planted, tree islands—planting in patches, and reference forest) at multiple sites in an agricultural landscape in southern Costa Rica. We inter‐planted two native species (Terminalia amazonia and Vochysia guatemalensis) and two naturalized N‐fixing...

Site description

Karen Holl
Descriptions of 15 original sites from Islas project. Used in various publications and described in Holl, K. D., J. L. Reid, R. J. Cole, F. Oviedo-Brenes, J. A. Rosales, and R. A. Zahawi. 2020. Applied nucleation facilitates tropical forest recovery: Lessons learned from a 15-year study. Journal of Applied Ecology 57:2316-2328.

Forest Survey data 2012-2013

Karen Holl
Vegetation composition of 6 representative forest fragments adjacent to restoration study plots in the Islas Project.

Data from: Ant–scale mutualism increases scale infestation, decreases folivory, and disrupts biological control in restored tropical forests

Andy J. Kulikowski & Karen Holl
Ant–hemipteran mutualisms can have positive and negative effects on host plants depending on the level of hemipteran infestation and plant protection conferred by ants against folivory. Differential effects of such mutualisms on plant survival are well documented in undisturbed and ant‐invaded systems, but few have explored how anthropogenic disturbance affects interactions between hemipterans and native ant species and what the consequences may be for recovering ecosystems. Within a fragmented landscape in Costa Rica, restored tropical...

A comparative study between outcomes of an in-person vs. online introductory field course

Alexandra Race, Maria De Jesus, Roxanne Beltran & Erika Zavaleta
The COVID-19 pandemic has disrupted many standard approaches to STEM education. Particularly impacted were field courses, which rely on specific natural spaces often accessed through shared vehicles. As in-person field courses have been found to be particularly impactful for undergraduate student success in the sciences, we aimed to compare and understand what factors may have been lost or gained during the conversion of an introductory field course to an online format. Using a mixed methods...

Data from: Testing applied nucleation as a strategy to facilitate tropical forest recovery

Rakan A. Zahawi, Karen D. Holl, Rebecca J. Cole & J. Leighton Reid
Active forest restoration typically involves planting trees over large areas; this practice is costly, however, and establishing homogeneous plantations may favour the recruitment of a particular suite of species and strongly influence the successional trajectory. An alternative approach is to plant nuclei (islands) of trees to simulate the nucleation model of succession and accelerate natural recovery. We evaluated natural tree recruitment over 4 years in a restoration study replicated at eight former pasture sites in...

Surrounding forest cover dataset 2005

David Morales, R. J. Cole, Karen D. Holl & R. A. Zahawi
Forest cover within 100 and 500 m radii from the center of each experimental plot was hand digitized from ortho-rectified 2005 aerial photographs and comprehensively ground checked. Forest cover spans a range from <1% to 66% within a 100-m radius surrounding the plots and from 9% to 89% in a 500-m radius.

Behavioral responses across a mosaic of ecosystem states restructure a sea otter-urchin trophic cascade

Joshua Smith, Joseph Tomoleoni, Michelle Staedler, Sophia Lyon, Jessica Fujii & Tim M. Tinker
Consumer and predator foraging behavior can impart profound trait-mediated constraints on community regulation that scale-up to influence the structure and stability of ecosystems. Here we demonstrate how the behavioral response of an apex predator to changes in prey behavior and condition can dramatically alter the role and relative contribution of top-down forcing, depending on the spatial organization of ecosystem states. In this study, a rapid and dramatic decline in the abundance of a meso-predator (Pycnopodia...

Birth timing after the long feeding migration in northern elephant seals

Richard Condit, Roxanne S. Beltran, Patrick W. Robinson, Daniel E. Crocker & Daniel P. Costa
A prominent phase of the annual cyle in migratory animals is the transition between migration and reproduction. The transition is a small part of the annual cycle, but details of its timing deserve attention. From a distant location, animals must initiate a long migration so that they arrive at the breeding ground on a precise schedule. Here we take advantage of a sample of female northern elephant seals that were tracked by satellite during their...

Data from: Tropical forest restoration enriches vascular epiphyte recovery

John Leighton Reid, José Miguel Chaves-Fallas, Karen D. Holl & Rakan A. Zahawi
Vascular epiphytes constitute a large proportion of tropical forest plant biodiversity, but are among the slowest plants to recolonize secondary forests. We asked whether tree planting for ecological restoration accelerates epiphyte community recovery. Does the spatial configuration of tree planting matter? What landscape contexts are most suitable for epiphyte restoration? Location: Restored pastures in premontane Coto Brus County, Puntarenas, Costa Rica.

Soil nutrients

Karen Holl
Surface soil nutrients collected in 2007, 2012, 2017 from research plots described in Holl, K. D., J. L. Reid, R. J. Cole, F. Oviedo-Brenes, J. A. Rosales, and R. A. Zahawi. 2020. Applied nucleation facilitates tropical forest recovery: Lessons learned from a 15-year study. Journal of Applied Ecology 57:2316-2328 (https://doi.org/10.1111/1365-2664.13684).

Canopy cover data from: Applied nucleation facilitates tropical forest recovery

Karen D. Holl, J. Leighton Reid, Rebecca J. Cole, Federico Oviedo‐Brenes, Juan A. Rosales & Rakan A. Zahawi
Applied nucleation, mostly based upon planting tree islands, has been proposed as a cost‐effective strategy to meet ambitious global forest and landscape restoration targets. We review results from a 15‐year study, replicated at 15 sites in southern Costa Rica, that compares applied nucleation to natural regeneration and mixed‐species tree plantations as strategies to restore tropical forest. We have collected data on planted tree survival and growth, woody vegetation recruitment and structure, seed rain, litterfall, epiphytes,...

Data from: Rules of thumb for predicting tropical forest recovery

Karen D. Holl, John Leighton Reid, Federico Oviedo-Brenes, Andy J. Kulikowski & Rakan A. Zahawi
Natural regeneration is increasingly recognized as a potentially cost‐effective strategy to reach ambitious forest landscape restoration targets, but rates of recovery are notoriously variable. We asked how well initial habitat conditions after cessation of agriculture predict forest recovery after nearly a decade. We aimed to provide land managers with general rules of thumb to assess when it is necessary to invest resources in active restoration, such as tree planting, to accelerate forest recovery. Location: Coto...

Elkhorn Slough eelgrass restoration

Kathryn Beheshti
The global decline of marine foundation species (kelp forests, mangroves, salt marshes, and seagrasses) has contributed to the degradation of the coastal zone and threatens the loss of critical ecosystem services and functions. Restoration of marine foundation species has had variable success, especially for seagrasses, where a majority of restoration efforts have failed. While most seagrass restorations track structural attributes over time, rarely do restorations assess the suite of ecological functions that may be affected...

Registration Year

  • 2021
    29

Resource Types

  • Dataset
    29

Affiliations

  • University of California, Santa Cruz
    29
  • Organization For Tropical Studies
    10
  • Organization for Tropical Studies
    4
  • Missouri Botanical Garden
    3
  • Virginia Tech
    2
  • University of Costa Rica
    2
  • Stanford University
    1
  • The Arctic University of Norway
    1
  • Universidade Cidade de São Paulo
    1
  • University of Alberta
    1