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The Effects of Environmental Features and Overstory Composition on the Understory Species Assemblage in Sub-Mediterranean Coppiced Woods : Implications for a Sustainable Forest Management

Tardella F. M., Postiglione N., Vitanzi A., Catorci A.

Polish Journal of Ecology

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2017

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Vol. 65, nr 2

167--182

EN

Understanding the relationship among environmental factors, overstory and understory is a key step for the improvement of sustainable forest management. Our aim was to understand how environmental features (topographic factors) and overstory (tree species) composition affect understory (shrub and herb species) assemblage in sub-Mediterranean coppiced woods. The study area lies in the Monti Sibillini National Park (central Italy). In 205 plots (20 × 20 m) we collected topographic features and species cover values; moreover, we defined the Social Behaviour Type (SBT — i.e. species ecological and dynamic features) of each understory species. Data were analysed using Redundancy Analysis and Generalized Linear Modeling. We found that topographic factors shaped percentage cover of different tree species and hence determined forest community type. Topography-related factors were further mediated by the tree layer composition, in filtering understory assemblage, on the basis of species SBT. We found no effect of overstory species diversity on understory species diversity. However, the presence of tree species different from the dominant ones increased understory species richness. This effect was particularly notable in evergreen woods, dominated by Quercus ilex. We conclude that, to improve the management sustainability, coppicing management should be focused on the achievement of the greater tree species diversity.

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Distribution of the nurse species pycnophyllum molle J.Rémy and P. Weberbaueri Muschl. in the Andean dry puna (Arequipa district - Southern Peru): role of topographic/soil variability and disturbance regime

Catorci A., Piermarteri K., Tardella F.

Polish Journal of Ecology

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2014

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Vol. 62, nr 2

385--390

EN

The dry Puna is the widest pastoral ecosystem of the tropical alpine Andes, characterized by harsh environmental conditions (long and intense drought stress periods and unfertile soils) and grazed by wild and domestic camelids. In these conditions, facilitation is of key importance in plant diversity conservation. Indeed, facilitation is a positive plant-plant interaction by which the so called nurse species provide environmental amelioration of harsh conditions and/or refuge to other plants (beneficiary species), which otherwise might fail to establish. The research aims were to understand which ecological variables affect the distribution of the potential nurse cushion species Pycnophyllum molle J. Rémy and P. weberbaueri Muschl., and if these species are affected by grazing disturbance. The study area (4000–4900 m a.s.l.) is located in the southern Peruvian Andes. Data of species cover, topographic and soil features, besides type of disturbance were collected along transects. We used canonical redundancy analysis to understand the relations between the cover of the two Pycnophyllum species and the above mentioned constraining variables. Results indicate that both the Pycnophyllum species grow on sandy loam, moderately acid soils, with low organic matter and very poor nitrogen content, and avoid high disturbance intensities. P. molle is more sensitive than P. weberbaueri to disturbance, and grows on relatively more fertile soils, also at higher altitudes and on steeper slopes characterized by greater rockiness.

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Effect of long-term abandonment and spring grazing on floristic and functional composition of dry grasslands in a Central Apennine farmland

Catorci A., Cesaretti S., Gatti R.

Polish Journal of Ecology

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2013

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Vol. 61, nr 3

505--517

EN

Semi-natural dry grasslands host some of the most valuable habitats in Europe, due to their biodiversity heritage. Nevertheless, a strong decline in their extension, due to the cessation of traditional management, has been observed in the last decades. The aim of the study was to assess plant community changes due to abandonment and the effect of spring grazing in sub-Mediterranean dry grasslands, focusing on the plant functional traits involved in this turnover. The study area is located in the central Apennines (Italy), where grasslands were grazed by sheep in late winter and spring until 1980 and are nowadays abandoned. Relevés sampled (using the Braun-Blanquet method) in different years, namely in 1976–1980 (grazed pasture) and again in 2010 (abandoned pasture) were compared. Results indicated that abandonment leads to the increase of species richness. Traits and strategies indicator sets were: therophyte for the grazed pasture; geophytes, flower palatability, early flowering strategy, clonal ability and presence of storage organs for the abandoned ones. Traits related to low levels of stress (tolerance strategies) are heavily reduced in grazed systems, and thus the functional composition of plant community is mostly characterised by traits promoting avoidance strategies. In abandoned conditions a higher number of species can co-exist thanks to the micro-scale variation of soil features and niche diversification. The research findings also revealed grazing timing as a key factor for understanding changes of plant functional trait patterns and spring grazing as a threat for orchid species.

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Seedling survival and dynamics of upper timberline in Central Apennines

Catorci A., Scapin W., Tardella F., Vitanzi A.

Polish Journal of Ecology

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2012

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Vol. 60, nr 1

79-94

EN

Despite several studies on the timberline dynamics in Europe were carried out in the last decades, very few papers refer to mountain areas where the timberline is composed of broadleaved trees, and no research was conducted on the dynamics of Apennine beech timberline in relation to seedling survival. The research aim was to analyse the beech wood timberline dynamics in the central Apennines, with reference to seedling survival. Furthermore, factors affecting seedling survival were identified. To assess the forest ecotone dynamics, vegetation layer cover, rock fragment cover and information about forest management and krummholz occurrence were collected in sampling plots placed over 1,600 m a.s.l., on north-facing slopes. The beech seedlings occurring in Brachypodium genuense-dominated stands above the timberline were counted and monitored along two growing seasons. Soil temperature, soil moisture, and photosynthetically active radiation available for seedlings (PHAR) in grasslands above timberline were measured. The research outputs indicate that timberline is not a natural boundary and that there is no evidence of its extension upwards. The greatest number of beech seedlings was recorded in late spring. The one-year mortality rate ranged from 71 to 100%. None of the seedlings still alive in the early autumn of the first year were recorded in the following spring. The competitive exclusion by Brachypodium genuense individuals, which limit the incident PHAR, and the low soil moisture during summer, were identified as the main factors that account for the high mortality of seedlings and affect beech regeneration above timberline. The effect of competition is probably intensified by the lack of pioneer shrubs which could otherwise serve as nurse plants for beech seedlings and protect them from browsing by wild ungulates. Thus, both the current and the past land use may be considered as driving forces in timberline dynamics. Probably, also the trend of global warming, that in the Mediterranean and sub-Mediterranean climatic context would determine the increase of summer drought stress, could worsen the effect of competitive exclusion of beech seedlings, so that it can be hypothesized that the expansion upwards of the upper timberline in the Apennines could be totally blocked.

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Regeneration of Ostrya carpinifolia Scop. forest after coppicing : modelling of changes in species diversity and composition

Catorci A., Vitanzi A., Tardella F., Hrsak V.

Polish Journal of Ecology

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2011

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Vol. 59, nr 3

483-494

EN

In temperate forest ecosystems, management is one of the most relevant factors that can drive the temporal pattern of species. As species in an ecosystem show susceptibility to stress and disturbance, it is useful to take into account the plant community .compositional dimension., which derives from species behaviour and ecological attributes and provides information on the mechanisms underlying species assemblages. Taking into account the influence of environmental factors on species diversity and composition, in order to determine the most suitable ecological behaviour type of each species, the research aim was to generate a model for Ostrya carpinifolia coppiced woods (central Italy) that describes forest ecosystem regeneration after coppicing by the assessment of change in the composition of ecological behaviour types. Vascular species cover percentage, field data, soil data, light intensity at the undergrowth, dominant tree layer cover and time since last logging were recorded for 63 plots covering 400 m2 each (20 x 20 m), randomly selected within a set of homogeneous macro-environmental conditions. Low species richness is related to stressing factors (acid soil, high soil skeleton percentage), while high species richness is linked to high light intensity at the undergrowth level due to scarce canopy cover soon after coppicing. The driving forces affecting floristic composition, highlighted through multi-response permutation procedures (MRPP) were light intensity at the undergrowth, regenerative phase, dominant tree layer cover, acidity, presence/absence of outcropping rock or rock fragments and total nitrogen content. Six species groups, each one characterized by homogeneous ecological behaviour, were defined by indicator species analysis (ISA) and tested using bioindication values analysis. Floristic successional change, related to time since last coppicing, turned out to follow an ecological cycling process characterized by cyclical occurrence/disappearance of species belonging to the six groups.

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Functional differentiation of Central Apennine grasslands under mowing and grazing disturbance regimes

Catorci A., Ottaviani G., Ballelli S., Cesaretti S.

Polish Journal of Ecology

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2011

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Vol. 59, nr 1

115-128

EN

This research dealt to two grasslands potentially developing the same vegetation type because sited in the same environmental contest (bioclimate, substratum, soil, slope, altitude) but under diverse management regimes (grazing and mowing) for many decades. The evidenced differentiation between the two pastoral vegetations can be attributed to disturbance type and the statistical functional analysis performed through seven plant traits (prostrate form, early flowering, storage organs, clonal ability, basal meristems, chemical defences and hairs), revealed the distinguishing patterns. Discriminant analysis pointed out typical biological attributes for each disturbance conditions, while from correlation analysis emerged different possible traits combinations which do not follow the previous traits separation. Such outcomes are explainable because both grazing and mowing provoke aboveground phytomass removal, although grazing is a selective pressure, while mowing gives to all the species the same development chances. It is reasonable to conclude that convergent strategies within the two systems are possible and frequent.

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Assessment of floristic diversity, functional composition and management strategy of North Adriatic pastoral landscape (Croatia)

Vitasović Kosić I., Tardella F., Ruscić M., Catorci A.

Polish Journal of Ecology

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2011

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Vol. 59, nr 4

765-776

EN

European semi-natural calcareous grasslands are species-rich ecosystems, considered as priority habitats by the European Union (92/43/EEC Directive) and judged worthy of conservation. They are in strong decline in extension and are threatened by abandonment throughout Europe. It is known that grasslands management (grazing, mowing) acts as driving force in plant community diversity, which in turn is an important conservation aim of European environmental policies. The area of current pastoral landscape (about 1000 ha) of the North Adriatic (Cicarija, Croatia) was studied in order: 1/ to understand which factors drive floristic differentiation . environmental features and/or grassland management conditions, 2/ to identify indicator species sets linked to those factors and 3/ to appraise the effects of management type on the coenological and functional composition of indicator species. 73 phytosociological releves were carried out; for each of them field data (altitude, aspect, slope and land form), productivity measurements and information on grassland management were collected. Redundancy analysis (RDA) identified a productivity-related soil moisture gradient as the environmental driving force of grassland floristic differentiation. Indicator species analysis (ISA) detected the indicator species sets related to environmental features and management type. The results indicate that undergrazing and the lack of periodic mowing are responsible for the higher total variance of floristic data set explained by environmental parameters rather than by management (use/not use). For the same reasons, the variations that emerged from comparison of the functional characteristics of the indicator species of grazing and of mowing (avoidance strategy, life form, and storage organs) proved more important than those observed in comparing used and abandoned grasslands. The management system adopted (grazing or mowing) appears in turn to be conditioned by the soil moisture/productivity gradient.