Soil variability through spatial scales in a permanently disturbed natural spruce-fir-beech forest

Abstract

Soil variability was assessed in a 74.2-ha area within the Ž ofínský prales natural forest. Parameters evaluated for 1765 soil profiles inside 353 graticule plots were as follows: (1) thickness of organic horizons, (2) thickness and form of mineral horizons, (3) humus form (HF), (4) soil taxonomic unit (STU) and (5) anomalies. In addition, soil reaction (pH KCl ) and oxidizable carbon content (C ox ) were measured in the laboratory for 734 samples from the upper mineral (A) and lower mineral (B) horizons. The most frequently occurring humus form was mor followed by moder, hydromor and peaty T-horizon. Entic Podzols, Dystric Cambisols, Haplic Cambisols, Albic Podzols, Histic (or Haplic) Gleysols, Endogleyic Stagnosols, Fibric or Hemic or Sapric Histosols and Stagnic Gleysols were all present at the site despite its homogeneous geological bedrock. Overall coefficient of variance (CV) was lower in terrestrial soils compared with (semi-)hydromorphic soils. Overall variance decreased in both soil groups with increasing depth, as did CV differences between the fine (up to 10 m) and the locality scales. The lowest CV values occurred for C ox and pH KCl . The CV values differed between STUs as well. Compared to lower horizons, variograms of upper horizons showed greater autocorrelation at the intermediate spatial scale (10-320 m)-ranging from 50 to 150 m. Semivariance values, however, reached 70-80% of sill already at a distance of 10 m. The most significant factor of variability at all studied spatial scales is presumably the soil disturbance regime, followed by terrain micro-topography and the effect of tree species.

Individual‐based approach to the detection of disturbance history through spatial scales in a natural beech‐dominated forest

“…The predominant range of disturbances between 10 and 40 m corresponded roughly to the range of weathering‐soil‐horizon thickness ( = B‐horizon, = Cambic or Spodic horizon; see Šamonil et al. ), but was significantly shorter compared to ranges of other soil properties (thickness of upper horizons, carbon content, soil reaction). We suppose that the renewal of organic and A‐horizons after uprooting events is more rapid than in the mineral B‐horizons where restoration lasts for many years after the levelling of typical pit‐mound micro‐morphological forms (Šamonil et al.…”

“…In general, this indicates high variability in the process of regeneration, as there are unusually small pulsating gaps on the one hand, and wider non‐closed gaps (including edaphic gaps) for longer periods on the other hand (Šamonil et al. ). The results suggest that historical and geographical contingencies influence ecosystem development via sequence, timing and initial conditions of disturbance events, and could be more important factors than global laws.…”

“…Pit‐mounds (microtopographical shapes caused by a single uprooted tree, with or already without the uprooted trunk) currently cover 11.6% of the total area, with 7.7% consisting of mound areas and 4.0% of pit areas (Šamonil et al. ).…”

Estimating the effect of tree uprooting on variation of soil horizon depth by confronting pedogenetic simulations to measurements in a Belgian loess area

“…Knowledge of the effect of tree uprooting on spatial soil variability is limited [ Šamonil et al ., , ], but effects on soil genesis (e.g., proxied by soil depth) have been demonstrated. In certain areas, the presence of pit‐and‐mound microtopography is a visible evidence of natural bioturbation processes.…”

Geomorphological impacts of a tornado disturbance in a subtropical forest

“…Treethrow microtopography can persist in some cases for up to 6 ka (Šamonil et al, 2013), suggesting that associated pedologic impacts can persist for comparable periods. Spatial patterns of soil that reflect forest disturbances (e.g., Šamonil et al, 2011;Valtera et al, 2013), suggest either pedological memory of disturbance effects, or disturbance recurrence intervals less than pedological relaxation times.…”