1,721,033 research outputs found
JOINT INTENSIVE COURSE ON GRASSLAND MANAGEMENT (C3) TRANSUMAN
No full textJOINT INTENSIVE COURSE ON GRASSLAND MANAGEMENT (C3)
TranSuMan
Advanced training on sustainable management of pastoral systems
Agreement Number: 2021-1-IT02-KA220-HED-000032227
09-12 May 2023, Camerino, ITAL
Context-dependent response of the trait-related flowering pattern in sub-Mediterranean grasslands
No full textThe timing of flowering is a key component of community assembly, being critical to competition for resources or avoidance of stress. In grasslands, the functional differentiation of
species inside the community drives the flowering pattern, so that each phenological phase
relates to a specific set of functional traits. Although the temporal dimension is an important
factor in determining species assemblages, how plant traits respond to the heterogeneity of
resource availability has been identified mostly through observations of spatial variations.
To understand the role of temporal variation of resources in the species assemblage processes, we performed a trait-based phenological study in sub-Mediterranean grasslands (central
Apennines). We counted flowering shoots of species of three plant communities along a
productivity gradient in 1 m × 1 m plots, during the growing season. We calculated the mean
proportions of flowering shoots of species sharing traits related to resource acquisition and
stress tolerance and analysed their relations with soil temperature, soil humidity, and canopy
height, comparing their temporal patterns using indicator species analysis, redundancy analysis, variation partitioning, and generalized linear modeling.
Our results highlighted that the temporal gradient, which synthesizes the variation trend of
the environmental conditions and vegetation structure of the grassland communities during
the growing season, is a major factor in determining the trait-based flowering pattern. In the
early flowering phases, there is a predominance of species with strategies of slow resource
acquisition and storage but rapid growth rate, while in the periods with optimal environmental conditions, the blooming species are the ones with strategies of slow growth rate and more
efficient resource acquisition, conservation, and use. No common patterns emerged among
plant communities for the late flowering species from mid-summer to autumn.
We also observed that the shift in soil temperature, soil relative humidity and canopy
height among communities reflected a modification over time of the flowering expression
of some traits, such as leaf anatomy and persistence, type of storage organ, and vertical
space occupation. Harsh conditions filter species with resource-retaining strategies, drought
resistance, and avoidance ability, whereas in productive conditions, competition for light
promotes the coexistence of species with dissimilar resource acquisition strategies on a fine
spatial scale. This seems to substantiate the hypothesis that the functional response to the
seasonal variation in environmental conditions largely retraces the modifications, at the community level, of the functional composition across spatial resource gradients.
Our results show that the amplitude of the environmental fluctuations influences the type
and number of strategies positively filtered by the system. Environmental fluctuations in time
influenced the trait-related flowering pattern more in highly productive conditions (having the highest differences in soil relative humidity and canopy height between spring and summer)
than in less productive ones. In fact, in productive conditions, the phenological responses to
environmental fluctuations are mostly related to traits that limit competition with dominant
species by spatial niche segregation (vegetative propagation, vertical space occupation, and
plant height) and to species that fit their life cycle to the variation of environmental conditions, through different life and leaf span. Conversely, such traits showed weaker trends in the
driest community, where the flowering pattern was less dependent on temporal fluctuations
of environmental conditions. These findings are consistent with the fluctuation niche theory,
based on the different growth/phenological response of species to the variation of resource
availability over time
Micro-topographyc gradients affect recovery processes after grazing cessation
No full textThough the interplay of grazing intensity and the availability of resources is a key driver in grassland composition, very few studies focused on trait changes after abandonment along productivity gradients. Through a comparative approach, we aimed to assess the context-dependent effects of long-term grazing cessation on functional composition and diversity in sub-Mediterranean grasslands. We hypothesized that variability of topography, soil and vegetation structure on a fine scale drives the trait-based dynamics after long-term abandonment, also influencing the patterns of functional diversity. On a calcareous mountain ridge of central Italy, we collected data on species cover and traits, site characteristics, soil depth and vegetation structure in 0.5 m × 0.5 m plots located in extensively grazed pastures and in grasslands abandoned since the early 1970s. We analysed patterns of species and traits in relation to environmental variables and management type, and trends in functional diversity (FD, Rao’s quadratic entropy) along a productivity gradient. We found that grazing cessation reduced the overall FD and that the direction of species and trait response after long-term grazing cessation were affected, on a fine scale, by the soil depth / productivity gradient. In dryer conditions, species and functional responses were less affected by abandonment, and were devoted to resistance to both stress and disturbance. In abandoned pastures we detected a significant decrease in FD with increasing productivity, leading to a shift from functional strategies devoted to grazing avoidance and tolerance to those devoted to competition for light and resource acquisition. This trend was related to the filtering effect of coarse tall grasses, which spread in highly productive conditions. In grazed grasslands, we detected an overall increasing trend of FD with increasing productivity, confirming the key role of extensive grazing in maintaining high levels of FD
Rapporti tra tipi vegetazionali e substrato roccioso nell’area umbro-marchigiana.
No full textIn this area, Ostrya carpinifolia woods with Quercus cerris are related to the diffusion of "calcari diasprini". Quercus pubescens woods almost exclusively pertain to ares covered by nappe detritus and calcareous-marly detritus; woody communities of Quercus cerris are explained by the presence of fersiallitic paleosols
Recovery of a grassland community invaded by Brachypodium rupestre after multi-annual mowing tratment
No full textA long-term experiment of mowing activities demonstrated the effectiveness of disturbance in recovering the invaded grassland communities (by Brachypodium rupestre) by the species richness increase and amelioration of the other indicators
Intra-specific multi-trait approach reveals scarce ability in the variation of resource exploitation strategies for a dominant tall-grass under intense disturbance
Full text linkMowing is a suitable practice to restore the grassland coenological composition after invasion of tall-grasses. However, how it affects the tall-grass intraspecific variation is still unknown. We investigated if mowing decreases the competitive ability of the tall-grass Brachypodium rupestre, and if this reduction is due to its poor ability to adapt to the new conditions by reducing resource investment in leaf and flower production, resource storage in belowground organs, increasing seed output and reducing seed mass. In 2017, we measured vegetative and reproductive traits of B. rupestre in two fenced areas in central Apennines (Italy). Half of each area had been mown twice a year since 2010 and half remained unmown. To investigate the effect of mowing on B. rupestre's functional strategies, we used linear mixed-effects modelling and correlation analysis. Mowing significantly reduced the trait values related to competitive ability/resource acquisition (vegetative height and leaf traits), resource storage (mature hypogeogenous rhizome), and sexual reproduction (mean seed mass, number of flowers, reproductive height), but increased seed output. We did not find significant variation of dry matter content in epigeogenous rhizomes and in the shoot number. B. rupestre is not prone to endure a prolonged disturbance, not being able to reallocate resources from acquisitive and retentive to reproductive structures. However, it is able to guarantee the presence of individuals to a certain degree by changing the reproductive strategies, such as decreasing the seed mass and increasing the seed output
How mowing restores montane Mediterranean grasslands following cessation of traditional livestock grazing
Full text linkTraditional land-use cessation allows the spread of invasive tall-grass species and thus leads to a reduction in grassland biodiversity. We hypothesized that long-term multi-year mowing of invaded grassland fosters the recovery of its taxonomic diversity and functional composition by reducing the dominance of the tall grass species Brachypodium rupestre, and that this change increases the pasture feed value. In 2010, we fenced part of a grassland, abandoned for about 30 years, invaded by Brachypodium rupestre (1 ha) in the central Apennine ridge (1,000–1,300 m a.s.l.), and cut it twice a year for six years; another area (1 ha) was fenced and left unmown. Before the experiment started, we recorded species cover in 30 random sampling units (0.5 × 0.5 m) in the experimental area and in the unmown area. The sampling was repeated for the experimental area, every year for six years, except 2013, while it was done for the unmown area only at the end of the six years. We investigated the effect of the reduction of Brachypodium rupestre over time on taxonomic diversity indices, functional traits and pastoral value, using species accumulation curves and generalized linear mixed-effect modelling. Twice-yearly mowing was effective in reducing the abundance of B. rupestre (mean cover 50.7 ± 19.8 % Standard deviation to 9.0 ± 7.2 %), and in increasing significantly species richness (16.6 ± 3.0–26.8 ± 3.2), exponential Shannon (8.8 ± 2.8–14.4 ± 2.7), but not Shannon evenness (0.53 ± 0.1 to 0.54 ± 0.1). At the end of the treatment quite stable richness and diversity values were reached. Reduction of B. rupestre cover increased the pastoral value of the system (39 ± 12 %–64 ± 8 % of pabular species relative cover) and promoted the presence of species without vegetative propagation (17.8 ± 12.3–28.2 ± 10.9), with pleiocorms (25.4 ± 14.3–49.6 ± 17.9), rosettes (5.6 ± 5.6–16.6 ± 12.7) and hemirosettes (32.1 ± 15.8–47.7 ± 13.6), but caused a decrease in species whose clonal growth organs have prevalent vertical spread (123.9 ± 25.7–97.0 ± 23.3), reptant (60.3 ± 20.9–20.2 ± 10.4), and late flowering species (67.4 ± 19.9–46.3 ± 17.2). The decrease of B. rupestre and the increase in mowing frequency reduced the abundance of species with clonal growth organs with prevalent horizontal spread (66.0 ± 19.5–17.9 ± 10.7), caespitose species (96.7 ± 20.9–43.6 ± 21.9), and grasses (94.0 ± 19.5–43.3 ± 22.0). Recurrent twice-yearly mowing seems to be appropriate in the restoration of sub-Mediterranean grasslands invaded by competitive species, facilitating the re-introduction of traditional grazing
Changes in species and functional composition in the herb layer of sub-Mediterranean Ostrya carpinifolia abandoned coppices
Full text linkIn recent decades, the traditional management of woods has ceased in several parts of the Apennine ridge, with the result that some woods have not undergone forestry for 40–70 years. The research aim was to assess the variation of species and functional composition in the herb layer of Ostrya carpinifolia woods (central Italy), after cessation of the usual management (coppice-with-standards). Using a space-for-time substitution, we compared stands at the end of the usual rotation cycle (20–25 years) with stands not subjected to silvicultural treatments for about 40–45 years and collected environmental and structural data. The main drivers of the herb layer modification, assessed using Ellenberg indicator values analysis and redundancy analysis (RDA), were primarily related to time since the last coppicing and wood structure. Results of indicator species analyses (ISAs) and Wilcoxon rank sum tests indicated that in abandoned coppices, the regenerative processes proceed through the spread of late-successional species, while the light filtering through canopy fosters species usually considered of fringe habitats. The functional strategies revealed by ISA and RDA underlined still stressful conditions in stands at the end of the usual coppicing rotation cycle, which might be thought as a legacy of the post-logging condition, and processes of recovery/maturation of the forest systems in abandoned woods leading to a better spatial and temporal niche partitioning. The preferential distribution of species usually growing in the Apennine beech woods supports the hypothesis that the studied O. carpinifolia woods are secondary forest ecosystems originating from the degradation of mixed beech woods
Concept mapping: a learning tool for higher education.
No full textTheoretical framework and application within Erasmus+ project ENEPLA
Valutazione agronomica con metodo fitosociologico dei pascoli del Monte Subasio (Umbria)
No full text- …
