قارن الطرق

	تحليل جدوى التجمعات السكانية (Population Viability Analysis)	نموذج الإسقاط المتكامل
المجال	علم البيئة	علم البيئة
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1981	2000
صاحب الطريقة	Mark Shaffer	Stephen Ellner and Mark Rees
النوع	extinction risk assessment	size-structured population projection
المصدر التأسيسي	Shaffer, M. L. (1981). Minimum population sizes for species conservation. BioScience, 31(2), 131-134.	Easterling, M. R., Ellner, S. P., & Dixon, P. M. (2000). Size-specific sensitivity: applying a new structured population model. Ecology, 81(3), 694-708.
الأسماء البديلة	PVA, extinction risk, minimum viable population, MVP	IPM, continuous size structure, kernel model, size-structured population
ذات صلة	4	4
الملخص	Population Viability Analysis (PVA), introduced by Shaffer (1981), estimates the probability that a population will persist over a given time period under specified conditions. PVA combines demographic models (Leslie matrices, IPMs) with stochastic simulation to project population trajectories, quantifying extinction risk. This allows conservation planners to assess whether a population will likely persist, evaluate management scenarios, and estimate the minimum viable population (MVP) size for long-term persistence. PVA is a decision-support tool, not a precise predictor.	Integral projection models (IPMs) are a class of structured population models that use continuous traits (size, age, height) to describe population dynamics. Introduced by Easterling and colleagues (2000) and developed extensively by Ellner, Rees, and collaborators, IPMs overcome limitations of age- or stage-structured models by treating individual traits as continuous. They use integration to project populations forward in time, making them particularly suitable for organisms with continuous size distributions or flexible developmental pathways. IPMs enable estimation of population growth rate (λ), sensitivity analysis, and projection under changing environmental conditions.