Plant diversity in a managed temperate deciduous forest: understorey response to two silvicultural systems

Abstract

Summary1. Disturbances and resource availability are key factors affecting plant diversity in managed forests. As disturbance regimes vary among silvicultural systems and may simultaneously affect different types of resources, effects on biodiversity can be unpredictable. 2. We compared the effects of two silvicultural systems on understorey plant diversity, including species composition, structural attributes and functional organization. One hundred and thirty-five phytosociological relevés were sampled from 27 forest stands managed under either a traditional coppice-with-standards (CWS, n = 12) or a 'close-tonature' selective cutting system (SC, n = 15), over similar edaphic conditions. Important environmental factors affecting vegetation were deduced using Ellenberg indicator values. Structural diversity was described using traditional indices of α and β diversity. Guilds were defined within the local pool of species using a set of 14 traits and their relationship with silviculture was assessed using correspondence analysis. 3. Post-logged CWS stands share some compositional and structural characteristics with selectively cut stands, including high species richness and a dominance of early successional species. However the species pool for all coppicing areas was higher than for selectively cut areas, suggesting that the high disturbance frequency occurring in the latter may progressively eliminate the most sensitive species. 4. Functional diversity strongly differs between the two systems. Although it is conserved through the silvicultural cycle in the coppice-with-standards system, some guilds were lacking in selectively cut stands. The most negatively impacted guilds were tree and shrub saplings, prostrated ruderals, shade-tolerant perennials and vernal geophytes. The latter two comprise 'true forest species' which may also be considered as 'coppicingmaintained species'. To reach the same values of guild richness (i.e. number of guilds) or redundancy (i.e. proportion of the maximal species richness within each guild), larger areas were required in SC compared with CWS systems. 5. In the SC system, the high proportion of light reaching the forest floor induced a spectacular spread of blackberries Rubus fruticosus agg., which decreased species richness. It also caused shifts in guild composition: graminoids and ferns grew strongly to the detriment of true forest species. 6. Synthesis and applications . Our results suggest long-term negative effects of selective cutting on both structural and functional plant diversity, compared with coppice-withstandards. Cutting intervals are shorter than recovery times, so that early successional species-dominated communities are maintained. Vernal geophytes and shade-tolerant perennials seem to be limited by the frequency of disturbance rather than by the severity of disturbance. We conclude that, from a biodiversity point of view, this 'close-to-nature' system does not cope with the objective of sustainable forest management. The rotations currently in use do not match n...

Examination the health state with instrumental measurements and the diversity of sessile oak stands in Zemplén mountains

“…In addition these species are proved to be appropriate indicators of the environmental changes because of their relative quick life cycle (Standovár et al 2006). The different types of disturbance have direct or indirect influences on the species composition and on the structure of the given layers (Brunet et al 1996, Decocq et al 2004, Van Calster et al 2008, von Oheimb & Härdtl 2009). The development state of the canopy and the ground layer has direct effect on the amount of light reaching to the latter layer, so that on the species composition and their coverage ratio in forest floor (Barbier et al 2008, Tinya et al 2009).…”

The influence of sample plot size on evaluations with Ellenberg indicator values

“…Major environmental factors, that have caused long-term changes in various types of vegetation, have been traced from the floristic composition of historical and recent data sets in forest vegetation (Wittig et al 1985;Hédl 2004), meadows (Knollová 2004;Bennie et al 2006) and weeds (Ejrnaes et al 2003;Lososová et al 2004). EIV can also be used to research appropriate management techniques (Decocq et al 2004) or for interpretation of patterns of species diversity (Cornwell & Grubb 2003;Ewald 2003a). Large database data sets have recently been subjected to such analyses (e. g., Wohlgemuth & Gigon 2003), as well as to calibrations using direct environmental measurements (Ertsen et al 1998).…”

Relationships between overstory and understory structure and diversity in semi-natural mixed floodplain forests at Bosco Fontana (Italy)

“…The understory cover-abundance values were used as weighted averages for computing Ellenberg's indicators. This approach is an alternative to direct field measurements of site characteristics (Ter Braak & Wiertz 1994, Decocq et al 2004). Environmental effects on understory attributes were investigated by the Pearson's r correlation test.…”

“…Mixed temperate forests show a high level of naturalness, thus becoming a basic reference for forest management (Meyer et al 2003, Balvanera et al 2006, Burrascano et al 2008, Gamfeldt et al 2013. New silvicultural systems have emerged during recent decades, based on the assumption that diversity patterns and ecological processes are more likely to persist when disturbances due to management mimic the patterns and processes of natural disturbances (Decocq et al 2004, Vandekerkhove et al 2009). Management regimes mimicking natural disturbances can contribute to diversify stand structure, and this may increase biodiversity through time (Falinski 1989, Frelich & Reich 2003, Campetella et al 2004) whilst aiming at economic targets and minimizing modifications of the forests (Emborg et al 2000).…”