DOI: 10.5061/dryad.mq3mq
title: Data from: Seed predation has the potential to drive a rare plant to extinction

description: 1. Pre-dispersal seed predation is sometimes considered unlikely to
 dramatically affect plant population growth because plants are generally
 expected to produce more seeds than there are safe sites for germination.
 Lupinus constancei is a rare herb of limited distribution, with fewer than
 400 reproductive individuals restricted to a single square kilometre of
 north-western California, USA. In addition to the vulnerability resulting
 from its extremely small population size, L. constancei faces heavy seed
 predation by small mammals. 2. As a stop-gap measure to prevent population
 decline, managers began covering a large number of the reproductive plants
 with herbivory exclosures in 2003, but the population-level effects of
 seed predation and the effectiveness of this caging treatment were
 unknown. We used ten years of demographic data to compare the population
 dynamics of plants inside herbivory exclosures with those sustaining
 ambient rodent seed predation. 3. We found that the stochastic population
 growth rate would be robust without seed predation (λs = 1.17), but
 without continued human intervention (i.e. use of exclosures), the current
 rate of predation would result in a decline towards extinction (λs =
 0.92). 4. After our study concluded, high mortality due to two extreme
 winter droughts followed by a wildland fire reduced the number of
 reproductive plants to ~103, making extinction of L. constancei more
 likely. 5. Synthesis and applications. The prevalence of consumer-driven
 population decline is largely unknown, but this study demonstrates that
 pre-dispersal seed predation by rodents can have powerful population-level
 effects, and represents one set of conditions under which consumer
 pressure has the potential to drive plant extinction. However, with
 continued management to limit the effects of seed predation in the
 short-term and investigation into the ultimate drivers of this high seed
 predation rate in the long-term, the Lassics lupine population could be
 restored to a robust rate of growth.
description: Forest Vital
 RatesVital rate means and
 variances from Forest site - needed to run Population Projection R
 scriptFPvitals.csvGermination Seed GridGermination data from seed grid experiment - used to calculate g11germination_seed_grid.csvLupinus constancei Monitoring DataMonitoring data from Lassics lupine (Lupinus constancei) - used to calculate vital rate means and variancesLUCO7 Monitoring v2010.accdbSeed Production DataSeed production data from 2010/2011 - needed to run Seed Production Analysis R scriptLUCO7productionAnalysisData.csvPopulation ProjectionR script to perform population projections - needs Saddle Vital Rates, Red Vital Rates, Forest Vital Rates, and Site Correlations data files to runLUCO7projection.RSaddle Vital RatesVital rate means and variances from Saddle site - required to run Population Projection R scriptMSvitals.csvSite Correlation DataVital rate correlations between sites - required to run Population Projection R scriptMultisitecorrdata.csvSeed Production AnalysisR script for analysis of seed data - requires Seed Production Data file to runproduction.RRed Vital RatesVital rate means and variances from Red site - required to run Population Projection R scriptRPvitals.csvProjection ScenariosDescription of projection scenarios found in Population Projection R scriptScenarios.docxSeed Survival AnalysisSeed survival analysis R script - requires Seed Survival Data file to runseedsurvival.RSeed Survival DataSeed survival data - used to calculate s1 - required to run Seed Survival Analysis R scriptseedsurvivalData.csv