Variability of soil properties in a landscape ecological survey in the Tuscan Apennines,Italy

The aim of this study is to test a landscape-ecological classification developed for surveys which make use of aerial photographs. This classification is based on relief, parent material and vegetation but leaves out soil properties which are important in landscape ecology. For this purpose, the variability of 11 surface soil characteristics is studied in selected plots of 2 × 3m, along a transect in an area of dissected fluvio-lacustrine deposits near Florence, Italy. It appears that much more than the 5 observations which were made in each plot are needed to establish reasonably accurate estimates of the mean of the variables.By means of a non-parametric test it is demonstrated that the adopted landscape-ecological classification is suitable for further surveying. This test is based on a comparison of all sample combinations for each variable, and for the variables combined per mapping unit. A discriminant function analysis confirms the results of this test.     

Clues to the genesis of a discontinuously distributed fragipan in the northern Apennines,Italy

At about 1000 m above sea level in the Vallombrosa Forest, northern Apennines, Central Italy, a dense pan that meets the diagnostic criteria for fragipans is discontinuously distributed. The unusual slope-parallel “digitate” distribution of the pan suggests that it could have formed on water-saturated soil material that moved as earthflows. Actually, several soils in the Vallombrosa Forest have buried or truncated horizons, indicating episodes of mass movement and deposition. However, the fragipan under study shows a homogeneous morphology throughout, hence not providing clues about the occurrence of episodes that have contributed to the emplacement of the parent material. Also, the physical, chemical, and mineralogical analyses of the fragipan do not reveal discontinuities that help to resolve distinct episodes of deposition. Nevertheless, discontinuities in features such as the degree of alteration of biotite grains and the amount of plasma, seen through the micromorphological investigation at 50–60 cm of the current depth, suggest the occurrence of at least two depositional events. Radiocarbon dating of large-size pieces of charcoal collected at three depths within the fragipan yielded three ages that may reflect different times of accumulation of the parent material during the last glacial period. Post-depositional micromorphological features, such as relatively undamaged clay coatings and a weak platy structure, indicate pedogenesis with the absence of intense pedoturbation.     

Soil algae from a maryland serpentine formation

Algae from serpentine soil samples collected at Soldiers Delight, Maryland (located in the west central portion of Baltimore County) were cultured using an enrichment technique. The algal flora was found to consist of members of the Cyanophyta, Chlorophyta and Chrysophyta (Bacillariophyceae). Composition of the soil flora at the division level is similar to that of more favorable soil types, indicating possible adaptations to high chromium and nickel concentrations and a low Ca: Mg ratio. Among the Cyanophyceae examined were three genera known to contain species which fix N₂. The presence of Cyanophyte genera capable of N₂ fixation suggests possible N input to this generally nitrogen-poor system. Lack of nitrogenase activity in collections of blue-green algal mats during early spring may be due to seasonal variation or Mo deficiency common in serpentine soils.     

Study of wet and dry atmospheric deposition at two altitudes in central Switzerland

The analysis of various ions in atmospheric deposition at two altitudes (515 m and 950 m a.s.l.) in Switzerland during 1983/84 revealed that dry deposition depends more on altitude than wet deposition. During autumn and winter, when vertical air exchange is limited, dry deposition of substances from anthropogenic sources (e.g. SO₄-S) was higher at the lower site. In the course of the year, the pattern of wet deposition was independent of altitude and showed highest rates for S, N and Ca in summertime. A comparison between rates of wet, particulate and gaseous S and N deposition suggested that during the growing season wet deposition is the dominant flux. Total (wet + dry) deposition of S, N and Cl was lower than in other parts of Europe, but a substantial increase of NO₃-N deposition during the past 25 years must have occured.     

Phaseolus genetic diversity maintained on-farm in central Italy

Thirty-one Phaseolus vulgaris L. and fivePhaseolus coccineus L. landraces reproduced on-farm werefound in central Italy. They were mostly grown by elderly farmers who usuallyselect for a certain type of seed. Different varieties are often grown in eachlocation and on each farm. They are maintained on-farm because of a local marketrequest for high quality products or because of sticking to traditional familyuse in cooking (21.2 and 75.8% of recorded cases, respectively). Three AFLPprimer combinations were used to assess genetic variation among collectedmaterials, a wild accession of P.vulgaris and commercial varieties of both species. Theyrevealed a quite high percentage of polymorphism (90.2% of polymorphic bands asan average). A wide genetic variation was observed among collected materials andeach accession showed a unique pattern of polymorphism. WithinP. vulgaris, landraces werediscriminated in two main subgroups, the former including the accessions fromthe Mediterranean area around the Lake Trasimeno and the latter includingaccessions from the humid Mediterranean area within the Appennine Mountains.These findings demonstrate the peculiar genetic identity of the landracesstudied also in relationship to human and environmental selection pressures.Possible on-farm conservation strategies are briefly discussed in relationshipto the information collected.     

Degradation,rehabilitation and sustainable management of a dunal ecosystem in central Italy

The history of the Feniglia Dune is an example of human-induced degradation and rehabilitation of a Mediterranean ecosystem. Between 1700 and 1900 the forest almost completely disappeared owing to intensive exploitation. The rehabilitation of Feniglia started at the beginning of 1900 with dune consolidation and the sowing of Mediterranean pines. Reforestation was long and complex, and was finished in the 1950s. The evolution of the vegetation can be studied from an aerophotogrammetric series (1955, 1968, 1985 and 1989). GIS was used to analyse the cartographic images. The vegetation dynamics was positive, showing increased plant cover at least until 1985. The 1989 map showed the beginning of cover recession, probably as the result of a number of concurrent disturbing factors: the evolution of the coastline, and an increase in grazing and tourism. Since the Feniglia Dune vegetation is not a resilient natural coenosis, it still needs the support of human interventions to safeguard its natural dynamism.     

A habitat model for brown bear conservation and land use planning in the central Apennines

We investigated the brown bear habitat suitability in an 8000 km² study area encompassing Abruzzo, Latium, and Molise regions in central-southern Italy. Based on long-term field surveys and published records, we classified bear habitat as occupied or unoccupied in 92 out of 320 sample squares (5 × 5 km). For each sample square 36 habitat variables were measured from topographic maps and Corine land-cover III level digital maps. The influence of habitat features on bear presence was investigated by multivariate and one-way analyses of variance and by logistic regression analysis. The logistic model correctly classified 95.5% of sample squares of bear presence and 93.8% of those where bears were absent. Average altitude, deciduous woodlands and ecotone length, showed a positive relationship with bear presence, whereas vineyard-olive groves and shrublands were negatively correlated with bear presence. No specific land management guidelines or strategies exist for bear conservation in central Italy, based on knowledge of habitat-population relationships. The landscape scale habitat model we developed could be useful to predict bear occurrence, to identify critical areas for a brown bear conservation strategy, and to enhance the arrangement of the protected areas network for the conservation of this species.     

Effect of lithological substrate on microbial biomass and enzyme activity in brown soil profiles in the northern Apennines (Italy)

The aim of the present study was to investigate the microbial activity along forest brown soil profiles sequence developed on different lithological substrates (carbonate or non-carbonated cement in sandstone formations) at different altitudes. The main question posed was: does carbonate affect the biochemical activity of brown soil profiles at different altitudes? For the purpose of this study, four soil profiles with different amounts and compositions of SOM developed on different lithological substrates were selected: two with carbonate (MB and MZ) and the other two with non-carbonated cement in the sandstone formations (MF1 and MF2). Chemical and biochemical properties of soil were analysed along soil profiles in order to assess the SOM quantity and quality, namely total organic C (C_org), water extractable organic C (WEOC) and humification indices (HI, DH, HR). Microbial biomass (C_mic and N_mic) content, as well as the specific activities of acid phosphatase, β-glucosidase and chitinase enzymes were chosen as indicators of biochemical activity. The soil biochemical properties provided evidence of better conditions for microorganisms in MB than in MF1, MF2 and MZ soil profiles, since patterns of microbial biomass content and activity might be expected in response to the amount and quality of organic substances. The different lithological substrates did not show any clear effect on soil microbial biomass content, since similar values were obtained in MF1, MF2 (with non-carbonated cement) and MZ (with carbonate). However, the specific activities of acid phosphatase (per unit of C_org and per unit of C_mic) were higher in soils with no carbonate (MF1 and MF2) than in soils with carbonate (MB and MZ). In conclusion, the biochemical activity along brown soil profiles was mainly regulated by different soil organic matter content and quality, while the two different lithological substrates (with carbonate or non-carbonated cement in the sandstone formations) did not show any direct effect on microbial biomass and its activity. However, the activity of acid phosphatase per unit of C was particularly enhanced in soil with non-carbonate cement in the sandstone formations.     

A sequence of marine terraces near Latina (Agro Pontino, central Italy)

A detailed physiographic soil survey has been carried out in the NW part of the Agro Pontino, near Latina. Four marine terraces and extensive eolian sand covers were found. The oldest marine terrace, the Latina complex, largely consists of augitic fine sands of marine-lagoonal origin. Towards the end of the transgression (of uncertain age) some minor sea level fluctuations occurred. The next marine terrace, the Minturno complex, is thought to date from the Tyrrhenian II transgression and was preceded by a major regression. This has the characteristics of a normal transgressive system, including late minor sea level fluctuations. The beachridge and lagoonal deposits are slightly tilted to the SW and are underlain by littoral gravels, most probably derived from the adjacent Latina complex through strong abrasion. Following a minor regression another marine terrace was formed (the Borgo Ermada complex). This terrace is considered to date from the Tyrrhenian III transgression, but has a regressive character, a phenomenon which can be explained by assuming a synformational tectonic tilting, some evidence for which is found. During a subsequent major regression (Würmian) eolian sands were repeatedly deposited, particularly on the Borgo Ermada complex. This was followed by the formation of a simple beachridge-lagoon system during the Holocene (the Terracina complex). The datings are based on correlation with sequences elsewhere, the two marine faunas studied give no clue as to their ages.Soil formation depends strongly on the texture of the parent materials and these relationships are indicated schematically. Soils in sands form a clear chronosequence, exhibiting an increased rubefaction and illuvial concentration of clay with age (Regosols - Arenosols - Luvisols). The distinction between the Borgo Ermada and Minturno complex is partly based on this chronosequence. Soils with a sandy albic E horizon, more or less abruptly overlying a stagnative clayey B horizon (Planosols and related soils) abound in intermediate materials of the Pleistocene terraces. The characteristically abrupt textural change was found to be due to the heterogenity of the parent material (eolian sand over loam to clay) rather than to soil formation.Some attention is paid to prehistoric artefacts, in particular Pontinian type tools and observations of BLANC on the famous site of Gniff-Gnaff are reinterpreted.     

Diclofop-methyl dissipation in clay soil under different tillage systems in central Italy

In order to evaluate the effect of simplified tillage systems on herbicide dissipation, diclofop-methyl residues were monitored in different soil layers (0–5 cm, 5–10 cm and 10–30 cm) under three different tillage systems: ploughing 25–30 cm deep (PT), disk harrowing 7–12 cm deep (RT) and no-tillage (NT) in a long-term experiment started in 1990 and carried out on clay soil. Diclofop-methyl residue concentrations in the soil were 0.25 ppm at peak time in topsoil and at lower quantities in the deeper layers. Diclofop-methyl residues in the topsoil were often higher with PT as compared to RT and NT. The presence of diclofop-methyl increased suddenly in untilled plots after a heavy rainfall period. This occurred in the 5–10 cm soil layer 60 days after application, and in the 10–30 cm soil layer 90 days after application. These data suggest a more rapid diclofop-methyl displacement to ground water through macropores under NT conditions.     

The umbric epipedon in the N Apennines,Italy—an example from the Vallombrosa Forest

The umbric epipedon is a diagnostic surface horizon recognized by both the World Reference Base for Soil Resources and the U.S. Soil Taxonomy. It is mainly characterized by a dark color, a moderate to high content of OM, and a base saturation of less than 50%. In the N Apennines, Central Italy, forest soils over 600–700 m a.s.l. often have this epipedon. This paper stresses the morphological, chemical, and biological properties of the epipedon, specifically in the Vallombrosa Forest, where considerable work has been done in the last decade. Here, the umbric epipedon forms on sandstone, in high forests of Abies alba, Fagus sylvatica, and Castanea sativa. It does not have homogeneous properties throughout its thickness and often is divided into two distinct genetic horizons, A1 and A2. The A1 horizon is thinner, darker, and richer in OM, more base‐saturated, and biologically more active than the underlying A2 horizon. The mean residence time of the bulk OM amounts to about a century in the A1 horizon, versus half a millennium in the A2. In both A1 and A2 horizons, the non‐humic fraction prevails in the OM; this could account for the high susceptibility of the umbric epipedon to degrade when the forest is clear‐cut or undergoes extensive uprooting due to windstorms or heavy snow loads. Significant discrepancies between the two A horizons have been found in regard to the microbial community. Umbric epipedons which developed under different tree species show minor differences, mainly concerning the microbial community.     

SW—Soil and Water: Monitoring Water Flow, Turbidity and Suspended Sediment Load, from an Apennine Catchment Basin, Italy

The aim of this paper is to discuss the results of a study conducted on the monitoring of the suspended sediment load and water flow of the Sillaro torrent, during 1997–2000. The river basin is located in the Northern Apennines in the province of Bologna in Italy. Its height is from 68 to 993 m above sea level. A clayey–waterproof soil characterises the 137·6 km² basin surface. The mean annual precipitation is 942 mm (1962–1983). The mean annual temperature is 11·8°C, while the maximum, registered in July, is 22°C.A station for measuring the amount of sediment yield and water flow was established at the outlet from the mountain basin of the Sillaro Torrent. The monitoring station was equipped with an ultrasonic flow meter and an automatic water sampler. The flow meter measured the hydraulic level, computed the water flow and sent signal to the water sampler, so that there would be a sample of sediment yield every 100000 m³ of water crossing the section.The suspended sediment concentration (SSC) and the turbidity were measured on the samples, and the water samples were analysed by a laboratory turbidimeter. The best relationship between turbidity and SSC was established and applied to the turbidity of the samples so as to obtain the concentration of the suspended sediment. It was concluded that firstly, the instrumentation used for hydrologic monitoring is reliable, secondly, a simple linear regression of SSC and turbidity is adequate for an accurate estimation of the load and thirdly the multiplicative model of the suspended sediment yield on water flow is a statistically significant relationship.     

Soil formation of new lahar materials derived from Mt. Pinatubo

The early stage of weathering / soil formation processes from new volcanic mudflow (new lahar materials) brought from Mt. Pinatubo was examined. For this purpose, comparative studies on the physical / chemical characteristics of the new lahar materials and soils formed by the deposition of old lahar materials were conducted. Original soils contained less coarse sand, more silt, and clay than the new lahar materials. Increase in the clay content of the original soils reflected the progression of weathering. The occurrence of a higher leaching process of Fe, Ca, and Mg and of a moderate accumulation of organic matter in the original soils was suggested, based on the differences in the soil elemental composition and chemical properties. Values of base saturation and phosphate absorption coefficient (PAC) of the new lahar materials were 388% and 44, while those of all the original soils ranged 15–160% and 55–894, respectively. With the progression of weathering, the PAC value tended to increase gradually while the base saturation value decreased abruptly under the environmental conditions prevailing in the Philippines.     

Ecology of soil lichens from Pliocene clay badlands of central Italy in relation to geomorphology and vascular vegetation

The terricolous lichen communities occurring under a temperate sub-arid to sub-humid climate (mean annual rainfall about 750 mm) on Pliocene clay soils of southern Tuscany (central Italy) are similar to those reported for arid or sub-arid areas, with mean annual rainfall around 200 mm. The distribution of these communities is influenced by the availability of bare soil and percentage cover of vascular plants. Where vascular communities are more important and pedogenetic processes lead to the development of more structured and evolved soils, pioneer lichen communities of the Toninio-Psoretum decipientis are replaced by communities such as that of Cladonietum convolutae, which are more capable of competing for light and nutrients with dense communities of tall grasses such as Bromus erectus. The distribution patterns of Artemisia cretacea and B. erectus among vascular plants, and Fulgensia fulgens and Cladonia rangiformis among lichens, account for most of the variability in vascular and lichen communities, respectively.     

Soil organic matter accumulation, litter decomposition and humus forms under mediterranean-type forests in southern Tuscany, Italy

The amount of organic matter and rate of litter decomposition in relation to vegetation type under mediterranean-type forests in southern Tuscany was studied. Since existing concepts are largely based on studies of soils on calcareous substrates in this region, particular attention was paid to soils on non-calcareous materials. The humus type and distribution at five sites on acid metamorphic rocks and at one site on dolomitic limestone with different vegetation types was investigated. The input of above-ground litter was also determined. On the metamorphic rocks, clear trends in humus profile development could be observed from deciduous through sclerophyllous to coniferous vegetation: there was a decrease in litter nitrogen content (9.3 to 5.8 g N kg^?1 DM), an increase in the amount of organic matter in ectorganic layers (2.53 to 4.66 kg m^?2), a decrease in the decay constant k (0.26 ± 0.02 to 0.17 ± 0.03 a^?1), and a decrease in soil faunal activity. The results indicate that, under eu-mediterranean to sub-mediterranean forests, decomposition rates are comparable to those under temperate deciduous forests, and that the dominant humus form is a leptomoder. The spatial variation in the amount of organic matter within the plots was considerable, and was related to vegetation type.     

Soil formation as affected by pit and mound microrelief in Massachusetts,USA

The influence of pit and mound microrelief on soil formation was investigated by detailed observations of a cross-section through a pit and mound in a hemlock (Tsuga canadensis) forest in western Massachusetts, in the northeastern United States.Soil forming processes during the last 140 years have led to taxonomically different soils due to this microrelief. Part of the annual precipitation apparently does not infiltrate into the mound but moves laterally through organic surface layers into the pits. This resulted in more intensified translocation of Fe, Al and organic matter in the pit profile. The ensuing soil met the spodic horizon criteria as defined in Soil Taxonomy and was classified as a Lithic Haplorthod. Neighboring, undisturbed soils had pronounced E, Bhs, and Bs horizons, the latter qualifying as spodic horizons on the basis of chemical criteria. These soils, however, did not meet the minimum depth requirement of 12.5 cm for spodic horizons and therefore, were classified as Typic Dystrochrepts. The soil developed in the mound showed less horizon development and was classified as a Typic Dystrochrept.Taxonomic changes resulting from the pit and mound microrelief affected less than 6% of the area and appeared not to have a significant impact on the purity of map delineations.     

Lichen biomonitoring of trace elements in a geothermal area (central Italy)

The epiphytic lichen Parmelia caperata was used systematically to biomonitor trace elements in the Travale-Radicondoli geothermal field (central Italy). The results showed a very low occurrence of potentially toxic heavy metals such as Cd, Hg and Pb, and relatively high values for As, B, Mo and elements associated with soil dust (Al, Co, Cr, Fe, Mn and Ni). Boron was the principal element of geothermal origin. Arsenic seems to originate both from power plants and adjacent thermal springs. It is concluded that trace element pollution in the area is low.