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PVA and VORTEX

PVA

PVA, or Population Viability Analysis, is a quantitative method used in the field of conservation biology to assess the likelihood that a species will persist over time in the face of various threats, such as habitat loss, climate change, and invasive species. By incorporating demographic data, environmental variables, and stochastic events, PVA models simulate population dynamics and help identify critical factors influencing species survival. This approach is essential for informing conservation strategies, prioritizing management efforts, and ensuring the long-term viability of biodiversity by providing insights into population trends and the effectiveness of different conservation interventions. Ultimately, PVA serves as a vital tool for understanding and mitigating the risks faced by endangered species and ecosystems.

PVA features in biodiversity database:

Categorization of PVA List

Category PVA Data
General Settings st, nruns, nyears, yrdays, npops, popbase, vmacrofile, rfile, animlistflag, fullanimlist, censusruns, outhflag, outgsvars, outpsvars, psinclude, excludelastpop, delaymort0
Environmental and Evolutionary Effects sp_inbrdepr, sp_lethalequiv, sp_percentlethals, sp_evldcorrelation, sp_evcorrelation, Inbreeding_depression, Population_supplementation, other population estimates
Population Density Dependence pop_densitydependence_ddrepro, pop_densitydependence_ddp0, pop_densitydependence_ddpk, pop_densitydependence_ddallee, pop_densitydependence_ddslope
Reproductive Rates pop_reproductiverates_evbreed, pop_reproductiverates_broodmean, pop_reproductiverates_broodsd, pop_reproductiverates_percentbreed, pop_reproductiverates_brood, pop_reproductiverates_broodsize, Percentage_of_females_breeding, Percentage_of_females_at birth
Mortality Rates pop_mortalityrates_evfemalemort, pop_mortalityrates_evmalemort, pop_mortalityrates_femalemort, pop_mortalityrates_malemort, Mortality_ages_0to1, Mortality_after_age_2, Mortality_ages_1to2
Carrying Capacity pop_carryingcapacity_k, pop_carryingcapacity_evk, pop_carryingcapacity_ktrend, pop_carryingcapacity_kchange, pop_carryingcapacity_kcriteria, pop_carryingcapacity_ktest, pop_carryingcapacity_kpriority, pop_carryingcapacity_allowk, pop_carryingcapacity_kallow, pop_carryingcapacity_kyears
Output and File Management extdef1sex, extdeffunc, ext threshold, extdefn, gdinclude
Catastrophe Data pop__catastrophe.label, pop__catastrophe.globallocal, pop__catastrophe.frequency, pop__catastrophe.severityrepro, pop__catastrophe.severitymort, pop_catastrophe1_globallocal, pop_catastrophe1_frequency, pop_catastrophe1_severityrepro, pop_catastrophe1_severitymort, pop_severe_el_nino_globallocal, pop_severe_el_nino_frequency, pop_severe_el_nino_severityrepro, pop_severe_el_nino_severitymort, pop_harsh_winter_globallocal, pop_harsh_winter_frequency, pop_harsh_winter_severityrepro, pop_harsh_winter_severitymort, pop_drought_globallocal, pop_drought_frequency, pop_drought_severityrepro, pop_drought_severitymort, pop_fire_globallocal, pop_fire_frequency, pop_fire_severityrepro, pop_fire_severitymort, pop_hurricane_globallocal, pop_hurricane_frequency, pop_hurricane_severityrepro, pop_hurricane_severitymort, pop_hurricanes_globallocal, pop_hurricanes_frequency, pop_hurricanes_severityrepro, pop_hurricanes_severitymort, pop_disease_globallocal, pop_disease_frequency, pop_disease_severityrepro, pop_disease_severitymort, pop_hunting_globallocal, pop_hunting_frequency, pop_hunting_severityrepro, pop_hunting_severitymort, pop_rodent_crash_globallocal, pop_rodent_crash_frequency, pop_rodent_crash_severityrepro, pop_rodent_crash_severitymort, pop_war_globallocal, pop_war_frequency, pop_war_severityrepro, pop_war_severitymort
Harvest Data pop_harvest_harvest, pop_harvest_startyear, pop_harvest_endyear, pop_harvest_interval, pop_harvest_harvcriteria, pop_harvest_iharvcriteria, pop_harvest_femalesage, pop_harvest_malesage
Supplementation Data pop_supplementation_supplement, pop_supplementation_startyear, pop_supplementation_interval, pop_supplementation_criteria, pop_supplementation_femalesage, pop_supplementation_malesage, pop_supplementation_endyear
Genetic Management Data pop_geneticmanagement_breedmaintaink, pop_geneticmanagement_avoidinbr, pop_geneticmanagement_avoidinbrf, pop_geneticmanagement_pairmkdynamic, pop_geneticmanagement_pairmkstatic, pop_geneticmanagement_setkin, pop_geneticmanagement_maxnmates, pop_geneticmanagement_numtriesfindmate
Other Data pop_monopolization, sex_monogamy, sex_ltmonogamy, sex_femalebreedingage, sex_femalelastbreedingage, sex_maxbroods, sex_usenormal, pop_initialpopulationsize_initialn, Age_of_maturity (months), pop_initialpopulationsize_femalesage, pop_initialpopulationsize_malesage, Reproductive_system, Maximum_age_reproduction, Broods_per_year, Offspring_per_brood, Percentage_of_females_at.birth, scenario, project, reps, runs, r, geomean, geomean bad, sd r, lambda, geomean good, sex_polygamy, sex_ltpolygamy, sex_hermaphroditic, sex_malebreedingage, sex_malelastbreedingage, sex_maximumage, sex_maxbroodsize, sex_sexratio, sex_usefulldistr

VORTEX

VORTEX is a population viability analysis (PVA) software tool widely used in conservation biology to model the dynamics of wildlife populations. It helps researchers and conservationists assess the long-term viability of species by simulating population changes over time under various scenarios.

The VORTEX simulator incorporates demographic data (such as birth and death rates), environmental variability, genetic factors, and stochastic events (like natural disasters or disease outbreaks) to predict population trends. By running multiple simulations, users can evaluate how different management strategies, habitat conditions, and threats impact a species' survival.

In relation to biodiversity, VORTEX plays a crucial role in identifying vulnerable populations and informing conservation efforts. It helps prioritize species and habitats for protection, assess the effectiveness of conservation actions, and develop recovery plans for endangered species. By understanding the dynamics of populations within their ecosystems, VORTEX contributes to maintaining biodiversity and promoting sustainable management practices that enhance the resilience of ecosystems in the face of environmental change.

Data Needed for a Population Viability Analysis (PVA) with Vortex

  1. Dynamic Life Table (Updated Annually):

    • Annual breakdown of the population’s age structure, survival rates, mortality rates, and fecundity for each age class.
    • This allows for real-time adjustments in the model based on observed population changes, enhancing the model’s responsiveness and predictive accuracy.

  2. Initial Population Size and Structure:

    • Number of males and females in each specific age class (e.g., 0-1 year, 1-5 years, etc.).
    • This detail is crucial to accurately modeling mortality and reproduction rates within each group.

  3. Probability of Reproduction by Female Age Class:

    • Proportion of females reproducing each year, broken down by age class.
    • It helps reflect changes in fecundity as females age.

  4. Litter Size:

    • Average number of offspring per reproductive event and annual variability in litter size.
    • Specify if litter size changes with age or environmental conditions.

  5. Age- and Sex-Specific Survival Rates:

    • Annual survival rates specific to each age and sex group (e.g., 75% annual survival for juveniles aged 1-3 years).
    • Include environmental variability (standard deviation) to simulate annual fluctuations.

  6. Age of Sexual Maturity:

    • Average age at which males and females reach sexual maturity.
    • This data defines when each individual can begin contributing to reproduction.

  7. Maximum Lifespan:

    • Documented maximum age for the species.
    • This sets a boundary for individual longevity in simulations.

  8. Immigration and Emigration Rates:

    • The average number of individuals entering and leaving the population each year.
    • Useful for simulating connectivity and evaluating the impact of individual movement.

  9. Inbreeding Coefficient:

    • Information on the initial inbreeding coefficient of the population.
    • Important for modeling inbreeding effects in small or isolated populations.

  10. Catastrophe Probability and Severity:

    • Frequency of specific catastrophic events (droughts, fires, diseases) and their impact percentage on mortality or fecundity.
    • Specify both the frequency (e.g., once every 10 years) and the reduction in survival or fecundity.

  11. Additional Genetic Data (Optional):

    • Initial level of genetic diversity, rate of diversity loss, and mutation rate.
    • These data help assess long-term genetic risks.

  12. Carrying Capacity (K):

    • Habitat carrying capacity, or the maximum number of individuals the environment can sustain.
    • Include any environmental variability affecting carrying capacity (e.g., fluctuations due to resource availability).

  13. Density-Dependent Mortality Rate:

    • How population density influences mortality or fecundity rates, especially when the population approaches carrying capacity.
    • This parameter is important to simulate the effects of resource competition.