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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

2013

Vol. 61, nr 3

505--517

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.

Effect of vegetation and management on occurrence of larvae and adults of generalist Maniola jurtina L. (Lepidoptera) in meadow habitats

Kulfan J., Strbova E., Zach P.

Polish Journal of Ecology

2012

Vol. 60, nr 3

601-609

Larvae and adults of some generalist insect species co-occur in identical habitats whereas adults and larvae of other generalist species do not co-occur and occupy different habitats. The Meadow brown, Maniola jurtina (L.) (Lepidoptera: Nymphalidae), is common and widely distributed in Europe where it is considered a habitat generalist. As knowledge about the occurrence of the larvae of the Meadow brown is scarce (different and more difficult methods are needed to collect larvae compared to adults) a complex assessment of the life strategy of this generalist is limited. We addressed here the question as to whether the adults and larvae of the Meadow brown co-occurred in the same habitats and how they depended on the type of grassland vegetation and habitat management. We expected co-occurrence of adults and larvae and similar effects of habitat management on them. We selected four habitat types belonging to the alliance Arrhenatherion elatioris W. Koch 1926, which form mosaic patterns in the rural landscape of central Slovakia: (1) extensive meadows mown once a year, (2) extensive meadows mown twice a year, (3) abandoned meadows, and (4) ecotones between deciduous forests and meadows mown once a year. Adults were counted in each habitat on seven transects 50 m long (in seven replicates) during the summer of 2003, 2004 and 2005. Larvae were collected in each habitat on 10 transects 50 m long (ten replicates) by sweeping vegetation (60 sweepings per transect) at night in May 2005 and 2006. Both adults and larvae occurred in all the mentioned types of habitats. A high abundance of adults and larvae was recorded in extensive meadows mown once a year and in ecotones. The lowest abundance of adults and larvae was found in abandoned meadows. The differences between abandoned meadows and ecotones (in the case of adults) and between abandoned meadows and extensive meadows mown once a year (in the case of larvae) were significant in all study years (P <0.05; multiple comparisons, K-W ANOVA). In the abandoned meadows the number of adults and larvae (median) was approximately 2 to 5 and 5 to 25 times lower than in the preferred habitats, respectively. Maximum numbers of both adults and larvae per single recording/sampling date were obtained in extensive meadows mown once a year; that is 185 adults in a transect 350 m long and 4 m wide and 267 larvae in the transect 500 m long (600 sweepings). Hence, similar to adults, larvae tend to be habitat generalists. Our results have confirmed the "advantageous" life strategy of M. jurtina which enables the species to adapt to a wide range of habitats, including those under strong pressure from humans. Comparing management practices in the study habitats, meadows which are mowed once a year were the most appropriate alternative for this species.