Influence of environmental predispositions on temperate mountain forest damage at different spatial scales during alternating drought and flood periods:case study in Hruby Jeseník Mts.(Czech Republic)

Mountain forests are more prone to environmental predispositions(EPs)than submountain ones.While remote sensing of mountain forests enables instantaneous damage mapping,the investigation of the causes requires field data.However,a local field or regionally modeled environmental characteristics influence remote data evaluation differently.This study focused on the evaluation of EPs effects damaging mountain forests between various spatial resolutions during environmental change.The evaluation was divided into managed and natural forests in the Hruby Jeseník Mts.(Czech Republic;240-1491 m a.s.l.;50.082°N,17.231°E).Damage was assessed through the discrimination analysis of the normalised difference vegetation index(NDVI)by MODIS VI during alternating drought and flood periods 2003-2014.The local environmental influence was assessed using the discrimination function(DF)separability of forest damage in the training sets.The regional influence was assessed through map algebra estimated via the DF and a forest decline spatial model based on EPs from differences between risk growth conditions and biomass fuzzy sets.Management,EPs and soil influenced forest NDVI at different levels.The management afflicted the NDVI more than the EPs.The EPs afflicted the NDVI more than the soil groups.Strong winters and droughts had a greater influence on the NDVI than the flood events,with the winter of 2005/2006 inverting the DF direction,and the 2003 drought increasing differences in managed forest biomass and decreasing differences in natural forest biomasses.More than 50% of declining managed forests in the training sets occurred on Leptosols,Podzols and Histosols.On a regional scale,the soil influence was eliminated by multiple predispositions.The EPs influenced 96% of natural forest and 65% of managed forest,though managed forest damage was more evident.The mountain forest NDVI decline was dependent on both management and risk predispositions.

Effect of gap size and forest type on mineral nitrogen forms under different soil properties

Gaps play a key role in forest ecosystem development and result from either natural processes or targeted forest management activities.The aim of this study was to investigate the interrelationships of soil properties in each of three forest types and two treatments,and to identify factors that influence levels of soil mineral nitrogen forms.The relation between mineral nitrogen and factors of soil parameters and stand type(European beech,Norway spruce,mixed stand)categories were investigated.The spruce forest type stored significant nitrogen in both mineral forms of nitrogen.Moreover,there was a significant linear dependence between N-NO3^-(nitrate anion)concentrations and cation exchange capacity(CEC)parameters such as base cation contents(S-CEC)and potential ureolytic activities(UreasePot),as well as between N-NH4^+(ammonium cation)concentrations and both hydrolytic acidities(Ha-CEC)and ureolytic activities.The dependence of N-NO3^-concentrations on S-CEC contents and UreasePot was negative,especially in adjacent stand.The dependence of N-NH4^+concentrations on Ha-CEC and UreasePot was week in the beech and mixed forest types while it was significantly positive in the spruce forest type.