Makroornogabeetan oinarritutako indize biotikoen sensibilitate analisia lurzoru erabilera ezberdinen aurrean.

Abstract

[EUS] Sistema lotikoek gizartearentzako onuragarriak diren zerbitzu ekosistemiko ugari dauzkate. Baina, erreka zein ibaiak, giza jardueren ondorioz kaltetuenak suertatu diren ekosistemak dira. Funtzio ekosistemiko hauek berreskuratu eta kontserbatzeko, gizakiak eragindako kalteak ezagutzea oso garrantzitsua da. Honetarako, azken urteetan indize biotiko ugari garatu dira, eta hauen bitartez erreken egoera ekologikoa aztertu daiteke. Ikerketa honetan, lur erabilera desberdinen (pinu eta eukalipto landaketak inpaktu modura eta baso autoktono edo hostogalkorren basoak kontrol modura) inpaktuak aztertzeko, makroornogabe bentikoetan oinarritutako 104 indize biotikoen egokitasuna ebaluatu zen. Lortutako emaitzetan, estrategia trofikoekin erlazionaturiko indizeek lurren erabilerak sorturiko inpaktua hobeto adierazten zutela ikusi zen. Dena dela, lur erabilera ezberdinen arteko banaketa ezberdina lortu da indize mota bakoitzarekin. Gainera, beste inpaktu batzuk detektatzeko diseinatutako indizeek ere diferentziak erakutsi dituzte hiru lur erabileren artean (uraren kutsadura kimikoa detektatzeko indize baten kasua, adibidez). Honela, ikerketa honetan, lur erabilerek erreketan duten inpaktua indize biotikoen bitartez neurtu daitekeela ikusi da, baina indize bakoitzak neurtzen duen inpaktuarekiko espezifizitatea kontuan izan behar da hauek aplikatzeko orduan.

[ENG] Rivers offer several ecosystem services to society, but they are among the most affected ecosystems by human activities. Identifying these harmful activities is really important in order to recover and preserve such ecosystem services. In the last years, different biotic indices have been developed to assess the ecological status of these systems. In this research, the suitability of 104 indices based on benthic invertebrates evaluating the impact of land use (pine and eucalypt plantations as impacts and deciduous forest as control) on streams was assessed. We found that indices related to trophic strategies were better to distinguish among different land uses. Nevertheless, different land uses didn’t show the same distribution for each type of biotic indices. Moreover, some of the indices which have been designed to detect specific impacts, such as water chemical pollution, also showed differences between land uses. Overall, we concluded that biological indices are a very useful method to quantify the impact of land use change in streams, yet we should keep in mind the specificity of each index to different impacts.