BROWN, G. G.

MASCHIO, W.

RCAAP - Repositório Científico de Acesso Aberto de Portugal

Earthworms (Pontoscolex corethrurus and Amynthas gracilis) effects on Eucalyptus spp. seedling growth.

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XVI ICSZ–InternationalColloquiumonSoilZoologySoilEcology–PosterPresentationsǦ116Ǧ[TU_SE_P14] Earthworms (Pontoscolex corethrurus and Amynthas gracilis) effects on Eucalyptus spp. seedling growth WAGNER MASCHIO1, GEORGE BROWN2 1Soils Department, Federal University of Paraná, Curitiba, PR, Brazil; 2Embrapa Florestas, Colombo, PR, Brazil  SeveralEucalyptusspeciesaregrown inBrazilasasourceofpulpwood forcelluloseand forbioͲenergy.Eucalyptusplantationspresentlyoccupyу4.8millionha inBrazilandaregrowingannually. However, little is known of the effects of these plantations on soil animals andlikewise, little is known of the potential effects of soil animals on Eucalyptus growth.Therefore, thepresentexperimentwasundertaken toevaluate theeffectsof two commonwidespread tropical earthworm species (Amynthas gracilis, Pontoscolex corethrurus) onseedlinggrowthofthreeEucalyptusspecies.Previousstudieshadidentifiedthesespeciesarethemain inhabitantsofEucalyptusplantationsat theEmbrapa Florestas research station inColombo, Paraná,Brazil. Eucalyptus (E. grandis, E. dunnii) seedlingswere planted in plasticpots(20cmdiam.)in4kg(airdry)ofanacid(pH4.2),humic(3.2%C)Cambisolcollectedwithand without A. gracilis, while E. benthamii and E. dunnii seedlings were planted with andwithoutP. corethrurus, toassess initialestablishment in field soil (like transplanting in fieldplots). Each pot received only one seedling and two A. gracilis (1.9Ͳ2.2 g potͲ1) or four P.corethrurus (1.8Ͳ2.1gpotͲ1).Thewormdensitiesaddedwere comparable to those found infield conditions forP. corethrurus,butnot forA.gracilis that ismuch less abundantunderEucalyptus.All treatmentswere replicated10 times.After50days,earthworm survivalandbiomass,soilfertilityandseedlingdiam.,height,aboveandbelowͲgroundplantbiomasswereassessed.Due toacold snap,all inoculatedP.corethrurusdied, leavingonlycocoons in thesoil.Ontheotherhand,A.gracilismortalityaveragedonly10% inbothtreatments,althoughtheirbiomasssignificantdecreased(to1.4Ͳ1.6gpotͲ1)attheendofthetrial.NeitherspeciesofearthwormaffectedthegrowthofE.dunnii.However,P.corethrurusincreasedtheheightofE.benthamii, but had no significant effect on the other plant parameters, while A. gracilisincreasedbothdiam. and above groundbiomassofE.grandis.Therefore,earthwormsmayhave importanteffectsontheestablishmentofEucalyptusseedlings inthesoil,alsoaiding intheirinitialgrowth.Anotherexperimentispresentlyunderway(endinginMay)toconfirmtheeffectsoflivinganddeadwormsonEucalyptus.Theresultsofthisandtheformerexperimentswillbepresentedintheposter. 

http://www.alice.cnptia.embrapa.br/alice/bitstream/doc/939464/1/EarthwormEffects.pdf

Earthworms (Pontoscolex corethrurus and Amynthas gracilis) effects on Eucalyptus spp. seedling growth.

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RCAAP - Repositório Científico de Acesso Aberto de Portugal

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