The research aims were to identify the flowering pattern and the related functional strategies in submediterranean mountain meadows (central Italy) and understand their relationships with some environmental and community structure variables. The number of flowering shoots per species was counted and environmental data were collected in 40 plots during 2009. Analysis of the species and trait data sets highlighted a flowering pattern and an underlying functional pattern. Dominant species tend to bloom in the central phases of the growing season\ud when no stress acts in the system and a long time is\ud available for plant growth and seed maturation. This kind of species does not need functional strategies allowing the canopy fast pre-emption or the tolerance to drought stress. Non-dominant species have two groups of functional strategies that allow them to share the same flowering period of dominant ones by a\ud different type of space occupation (spatial niche partitioning) or to flower before or after their flowering period (temporal niche partitioning). The functional strategies involved in the temporal niche partitioning have a dual ecological meaning, limiting competition with dominant species by fast growth and seed\ud maturation (e.g., short stature, mobilisation of stored reserves, colonization of unexploited soil niches by clonal growth organs and light seeds) and enabling tolerance to drought stress (e.g., scleromorphic and succulent leaves, persistent green leaves, tap roots) and to the low light availability at the ground level\ud owing to the change of grassland structure (e.g., tall size and upright growth form)
The present study examined a sub-Mediterranean pastoral system in the central Apennines (Italy) with a long history of\ud grazing, where winter cold stress is alternated with summer drought stress. The research goals were to ascertain whether\ud different floristic structures correspond to different stress conditions (xeric and semimesic), and whether peculiar functional\ud plant traits (such as avoidance and tolerance mechanisms) respond to stress/disturbance intensities, and understand how\ud vegetation reacts to changeable livestock pressure (through floristic and plant trait variations). Cluster analysis indicated that\ud separate communities develop under different stress intensities. Other analyses highlighted how avoidance strategies predominate within the pastoral system. Observations of grazed and ungrazed patches conducted in 10-m transects revealed spiny cushion formation in semimesic grassland, where a brief period of overgrazing occurs in late summer, causing variations in plant community structure. All these results confirm the importance of historical grazing and current land use, showing how small disturbances and stress variations cause ecosystem responses. Best practices for management were identified. In xeric conditions, it is advisable that the intensity of disturbance be lessened, while in semimesic grassland overgrazing should be forbidden during the dry period, because it could facilitate the development of spiny patches, and subsequent spread of Brachypodium rupestre
Questions: How does horse or sheep grazing affect species richness, diversity and functional composition of plant communities in sub-Mediterranean grasslands? What are the implications of grazing management for species conservation?\ud Location: Pastures dominated by Bromus erectus grazed by either sheep or horses in the Umbria-Marches Apennines (central Italy).\ud Methods:We examined grasslands at altitudes ranging from 1000 to 1200 m a. s.l. on north-facing slopes and with a slope angle of 20–40 °. In 20 plots of 1 m2 for each management type, canopy height and above-ground phytomass were recorded. In 120 plots (60 for eachmanagement type) of 1 m2 the cover value of each species was recorded. Floristic diversity and community similarity of the sheep- and horse-grazed conditions were compared. Functional plant traits and strategies or ecological requirements were also evaluated.\ud Results: The sward was shorter and supported less above-ground phytomass in the horse-grazed area. The sheep- and horse-grazed areas had similar floristic diversity. Accidental species were the species most affected. Plants with lownutrient\ud requirement spread in horse-grazed pasture. Functional traits of species were filtered by the system, resulting in diverse cover values of species. Horse grazing promoted plants with a robust defence strategy (avoidance and tolerance) that ensured leaves were replaced when horses were not grazing, as well as species with clonal growth. In the sheep-grazed area, a higher level of selective defoliation and a delayed start to the grazing period promoted species with low palatability, a late-flowering strategy and those intolerant to trampling by large herbivores (chamaephytes). The value of forage feed was slightly higher in\ud horse-grazed pasture. Grazing of horses was more effective than that of sheep for controlling dominant unpalatable tall grasses.\ud Conclusion: In terms of biodiversity conservation, horse grazingmay be considered as useful as sheep grazing, but only if managed at optimal stocking rates, because the increase in short grasses and annuals (growth forms with poor root systems) does not ensuremaintenance of soil on steep slopes
Questions: In order to preserve the ecosystem functioning of semi-natural\ud sub-Mediterranean calcareous grasslands of the Central Apennines, it is vital to\ud understand how functional diversity (FD) changes in relation to different types\ud of disturbance. To compare the effects of sheep grazing and those of late-summer\ud mowing, we asked: do different types of disturbance (grazing and mowing)\ud affect FD; are FD and species diversity positively correlated in both grazed and\ud mown grasslands; do FD and species diversity take different paths in the two\ud disturbance regimes; and are different FD values related to changes in the composition\ud of traits linked to competitive ability, resource acquisition and resistance\ud strategies?\ud Location: Grazed andmown sites in the Central Apennines (Italy).\ud Methods: We performed redundancy analysis and indicator species analysis to\ud characterize the trait composition of the two disturbance regimes. We calculated\ud FD for each selected trait and a compound FD for multiple traits, using Rao’s\ud quadratic entropy index. Differences in FD between disturbance regimes were\ud tested with a nested ANOVA. We performed a regression analysis between FD\ud and species diversity indices under the two disturbance types.\ud Results: Species and functional diversity were positively correlated in both disturbance\ud types. FD was generally less correlated with species diversity variations\ud in mown grasslands than in grazed ones, suggesting that late mowing\ud leads to higher levels of functional redundancy (i.e. to a wider overlap of species\ud functional composition). Late mowing promoted higher species and functional\ud diversities and a wider variety of functional traits in the plant\ud community. Grazing, besides negatively affecting the species diversity of grasslands,\ud reduced their FD by favouring the dominance of traits related to avoidance\ud and tolerance strategies.\ud Conclusion: The continuation of late mowing is recommended to preserve the\ud richness and variability of functional groups and the ecosystem functioning of\ud sub-Mediterranean grasslands
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