Effects of native and invasive Prosopis species on topsoil physiochemical properties in an arid riparian forest of Hormozgan Province,Iran

Biological invasions can alter soil properties within the range of their introduced,leading to impacts on ecosystem services,ecosystem functions,and biodiversity.To better understand the impacts of biological invasions on soil,we compared topsoil physiochemical properties at sites with invasive alien tree species(Prosopis juliflora),native tree species(Prosopis cineraria,Acacia tortilis,and Acacia ehrenbergiana),and mixed tree species in Hormozgan Province of Iran in May 2018.In this study,we collected 40 soil samples at a depth of 10 cm under single tree species,including P.juliflora,P.cineraria,A.tortilis,and A.ehrenbergiana,as well as under mixed tree species.The results showed that organic matter,moisture,potassium,calcium,nitrogen,and magnesium in topsoil at sites with A.tortilis and A.ehrenbergiana growing in combination with P.cineraria were higher than that at sites where P.juliflora was present(P<0.05).Sodium at sites with A.tortilis and A.ehrenbergiana growing in combination with P.cineraria and P.juliflora was lower as compared to that at sites with just A.tortilis and A.ehrenbergiana.Electrical conductivity was lower at sites with A.tortilis and A.ehrenbergiana growing in combination with P.cineraria,and it was higher at sites with mixed Acacia and P.juliflora trees.Based on the generally more positive effect of native Acacia and P.cineraria on topsoil physiochemical properties as compared to the P.julifora,afforestation with native tree species is preferable for soil restoration.In addition,due to the negative effects of P.julifora on soil properties,P.julifora spread should be better managed.

Impact of natural disturbance, forest management and vegetation cover on topsoil biochemical characteristics of Tatra Mts.(Slovakia)

Perturbations caused by windstorms usually lead to the harvesting and clearcutting of fallen trees and wood debris,especially in the areas of managed forest ecosystems.Induced shifts in soils due to management practices play a crucial role in the restoration and maintaining of key ecosystem services.This paper focuses on topsoil chemical properties in relation to vegetation type(trees,shrubs and herbs)evolving at windstorm damaged(in 2004)areas with former Norway spruce(Picea abies)forests in the Tatra Mts.region(Slovakia).We assessed the content of topsoil organic matter fractions(extractives,holocellulose(HC)and lignin(Lig)),carbon in microbial biomass(Cmic),soil organic matter(SOM)and the content of elements N,C,H and S.The study plots represent different types of post-windthrow disturbance history/regime:wooden debris extraction(EXT),wooden debris not extracted(NEX),wooden debris extraction followed by wildfire(FIR),affected by the windstorm in 2014 with the subsequent wooden debris extraction(REX)and unaffected(REF).Our results revealed significant differences among sites in the content of dichloromethane extractives(EXT vs.REX and FIR),acetone extractives(NEX vs.EXT,FIR and REF),ethanol extractives(FIR vs.EXT,NEX and REF),water extractives(FIR vs.REX,NEX)and Cmic(EXT vs.NEX,FIR and REF).The topsoil of Vaccinium myrtillus and Picea abies showed a higher ratio of C/N,N/Lig,and Lig/HC compared to Rubus idaeus,Avenella flexuosa,Calamagrostis villosa,and Larix decidua.The content of N,C,H and S varied between topsoil with shrubs(Vaccinium myrtillus,Rubus idaeus)and grasses(Avenella flexuosa,Calamagrostis villosa).A positive correlation between soil organic matter(SOM)and polar extractives(r=0.81)and a negative correlation between SOM and HC(r=-0.83)was revealed.The carbon content in microbial biomass(Cmic)is positively correlated with acid soluble lignin(ASL)(r=0.85).We also identified a strong correlation between Klason lignin(KL)and the Lig/HC ratio(r=0.97).