Been there, done that: Pre-Columbian occurrence in the wet, aseasonal, lowland rainforest of Ecuadorian Amazonia during the Arcaic period

Enca ni Mon oya1, Molly Spa e 2, Nú ia Cañellas-Bol à1, Mª Ca men T apo e1, Ca men X. Luzu iaga3, Rommel Mon ú a 4 1 Spanish Na ional Resea ch Council CSIC, Geosciences Ba celona GEO3BCN, Ba celona, Spain 2 Uni e si y o Li e pool, Depa men o Geog aphy and Planning, Li e pool, Uni ed Kingdom 3 Uni e sidad Tecnológica Equinoccial, Uni e sidad Tecnológica Equinoccial, Qui o, Ecuado Conside ing he as ex en hey occupy, opical Sou h Ame ican lowlands ep esen a egion la gely unde s udied, limi ing ob aining accu a e in o ma ion o he plan communi ies’ dynamics o such an ecologically and economic impo an a ea. Some o he easons o his low densi y o a ailable s udies a e he di icul y o a i ing and explo ing he s udy a ea, o e en once he e, inding sui able loca ions. Among he p oblems o inding sui able eco ds, wes e n Amazonia has been highligh ed as a e y geomo phologically ac i e loca ion, p e en ing he de elopmen o long, con inuous sedimen s spanning se e al housand yea s wi hou a sedimen a y gap o hia us. This egion has also been highligh ed as less likely o hold e idence in he p esen -day landscape o dense p e-Columbian popula ions. He e we p esen a Holocene sequence o wes e n no he n Amazonian lowlands, in he Ecuado ian Yasuní Na ional Pa k, ha spans he las 6000 yea s. The esul s show he con inuous p esence o a ain o es , bu wi h a high dynamism changing he abundance o he dominan axa se e al imes du ing he las 6000 yea s. In his sense, he o es wi h a highe e enness is he p esen -day one, es ablished du ing he las millennium. I is sugges ed ha changes in he ege a ion we e p ima ily d i en by geomo phological ac i i y including shi s in he d ainage sys em. Based on he occu ence o i e peaks and cul i a s, he p esence o humans in he s udy si e a ound 5000 yea s ago seems qui e plausible, which could ha e been only spo adic in he s udy a ea. Howe e , i is no ewo hy he absence o la ge changes in he ege a ion coe al o he an h opogenic indica o s. Today, he s udy si e is inhabi ed by Wao ani indigenous, and a chaeological emains ha e been ound nea by om he o ma i e pe iod, 3000 yea s la e . The esul s showed he e e idence he limi a ions o calcula e p e-Columbian peoples only based on isible p in s in p esen -day landscapes. P ojec e e ence: PID2022-138059NB-I00. And a S e ania Se ban1, Nicholas B anch1, Joy Singa aye 2, Ma in E. Timana3 1 Uni e si y o Reading, Depa men o Geog aphy and En i onmen al Science, Reading, Uni ed Kingdom 2 Uni e si y o Reading, Depa men o Me eo ology, Reading, Uni ed Kingdom 3 Pon i ical Ca holic Uni e si y o Pe u – Applied Geog aphy Resea ch Cen e , Depa men o Humani ies, Lima, Pe u The esea ch ocuses on econs uc ing and unde s anding he cause o expansions and con ac ions in Andean Polylepis woodland dis ibu ion du ing he Ea ly and Middle Holocene. Polylepis is a i e-in ole an genus ha lou ishes in a eas wi h minimal human ac i i ies and g azing impac . The e is cu en ly deba e in he li e a u e conce ning whe he humans o clima e we e he p ima y cause o he con ac ion and agmen a ion o hese woodlands o e he Holocene. We employ a mul i-p oxy app oach, including pollen and mic ocha coal analysis, as well as Species Dis ibu ion Modelling (SDM) o explo e he in luences o clima ic change, i e, and human ac i i ies. The po en ial pas dis ibu ion o i e endemic ee species is examined using an SDM app oach wi h MaxEn . Changes in woodland co e a e explo ed by p ojec ing he bioclima ic a iables om he high- esolu ion global clima e da ase CHELSA and he digi al ele a ion model o e he las 15 000 yea s. P elimina y esul s show ha o e his ime, Polylepis woodlands, de ined by he i e selec ed species, expe ienced a ious “pulses” in ol ing expansion, agmen a ion, and mo e ecen ly, signi ican con ac ion. No ably, he SDM e eals an expansion phase be ween app oxima ely 11.5kya and 10kya, ollowed by a end o con ac ion s a - ing a ound 5.5kya. P e ious s udies ha e asc ibed his con ac ion as a esul o exponen ial human popula ion g ow h in he egion a his ime. Howe e , ou esul s poin o clima ic change being a signi ican ac o .