03440naa a2200433 a 450000100080000000500110000800800410001902200140006002400410007410000250011524501530014026000090029352020800030265000170238265000250239965000290242465000240245365000250247765000180250265000260252065000190254665000240256565000180258965000220260765000250262965300270265465300220268165300180270365300290272165300200275065300400277065300170281065300270282765300260285465300220288070000190290270000200292177300650294119168202021-07-06       2012    bl uuuu     u00u1 u    #d  a0304-38007 a10.1016/j.ecolmodel.2012.01.0072DOI1 aGUARINO, E. de S. G.  aOccurrence and abundance models of threatened plant speciesbapplications to mitigate the impact of hydroelectric power dams.h[electronic resource]  c2012  aSpecies occurrence and abundance models are important tools that can be used in biodiversity conservation, and can be applied to predict or plan actions needed to mitigate the environmental impacts of hydropower dams. In this study our objectives were: (i) to model the occurrence and abundance of threatened plant species, (ii) to verify the relationship between predicted occurrence and true abundance, and (iii) to assess whether models based on abundance are more effective in predicting species occurrence than those based on presence?absence data. Individual representatives of nine species were counted within 388 randomly georeferenced plots (10 m × 50 m) around the Barra Grande hydropower dam reservoir in southern Brazil. We modelled their relationship with 15 environmental variables using both occurrence (Generalised Linear Models) and abundance data (Hurdle and Zero-Inflated models). Overall, occurrence models were more accurate than abundance models. For all species, observed abundance was significantly, although not strongly, correlated with the probability of occurrence. This correlation lost significance when zero-abundance (absence) sites were excluded from analysis, but only when this entailed a substantial drop in sample size. The same occurred when analysing relationships between abundance and probability of occurrence from previously published studies on a range of different species, suggesting that future studies could potentially use probability of occurrence as an approximate indicator of abundance when the latter is not possible to obtain. This possibility might, however, depend on life history traits of the species in question, with some traits favouring a relationship between occurrence and abundance. Reconstructing species abundance patterns from occurrence could be an important tool for conservation planning and the management of threatened species, allowing scientists to indicate the best areas for collection and reintroduction of plant germplasm or choose conservation areas most likely to maintain viable populations.  aBiodiversity  aEnvironmental impact  aEnvironmental protection  aHydroelectric power  aStatistical analysis  aTropical wood  aAnálise estatística  aBiodiversidade  aEssência florestal  aHidrelétrica  aImpacto ambiental  aProteção ambiental  aAnálisis estadístico  aBarra Grande (RS)  aBiodiversidad  aEnergía hidroeléctrica  aMadera tropical  aModelo de ocorrência e abundância  aPelotas (RS)  aPresence-absence model  aProtección ambiental  aRio Grande do Sul1 aBARBOSA, A. M.1 aWAECHTER, J. L.  tEcological Modelling, Marylandgv. 230, p. 22-33, Apr. 2012.