03027nam a2200169 a 450000100080000000500110000800800410001910000220006024501800008226001280026250000440039052023540043465000170278865000120280570000220281770000180283921767912025-06-25       2009    bl uuuu     u00u1 u    #d1 aAZEVEDO, V. C. R.  aImpact of selective logging on genetic diversity and spatial genetic structure in an Amazonian population of Manilkara huberi DuckeA.Chev. (Sapotaceae).h[electronic resource]  aIn: CONGRESO FORESTAL MUNDIAL, 13., 2009, Buenos Aires. Desarrollo forestal, equilibrio vital: anales. Argentina: FAOc2009  aNa publicação: Ana Yamaguishi Ciampi.  aTimber harvesting by selective exploitation leads to habitat fragmentation and may also drastically reduce the numberof reproductive individuals, with serious consequences for the maintenance of genetic diversity and long term survival of tree populations, duein part, to abiotic and biotic modifications of forest habitat. In this work we measured levels of genetic diversity, endogamy and spatial geneticstructure of a natural population of Manilkara huberi, an insect-pollinated tree, before and after commercial selective logging, applied accordingto the principles of the Reduced Impact Logging (RIL) system. A total of 443 adult trees from a 200 hectare plot at the Tapajós National Forestat the Brazilian state of Pará were genotyped at eight highly polymorphic microsatellite loci. The trees were classified as follows: 201 noncommercial (10 cm d.b.h. 50 cm) trees and 242 commercial (50 cm d.b.h. 140 cm) trees. After timber exploitation, the number of commercialtrees reduced to 134 individuals, 55% of the original. Similar levels of genetic diversity (He = 0.870 and 0.852) and endogamy (f = 0.190 and0.168) were detected in the commercial trees before and after harvesting, respectively. The loss of 16 rare alleles (freq 0.05) among eight lociin this subpopulation (commercial trees) was detected, which is 11.6% of the total number of alleles in the whole population pre-exploitation. Ofthose, 11 alleles (68%) are still present in the non commercial subpopulation. The significant spatial genetic structure observed in theunexploited population (as a whole) at a radius of 450 m was significantly reduced after exploitation to a radius lower than 350 m. Thecommercial individuals, which also had a spatial genetic structure (300 m) before logging, showed no significant spatial genetic structure afterexploitation. This data indicates a significant alteration in the distribution of genetic diversity in the area which may result in a different patternof genetic diversity and endogamy in the new generations. Overall our results indicate that there is a short-term genetic impact of selectivelogging on this population of M. huberi. However, the pattern of alteration is currently not clear, but may be clarified after the genotyping of anew group of seeds generated after exploitation. Financial Support: DFID/EMBRAPA/CNPq-PPG-7.  aBiodiversity  aForests1 aYAMAGUISHI, A. T.1 aKANASHIRO, M.