Damage by herbivore grazing negatively influences the development of subsequent forest generations. Little is known about the long-term impacts of grazing and interactions between grazing and light conditions on sapling growth after the cessation of herbivory impact. In this study, Taxus baccata saplings were grown over a period of four years in artificial shading at 2, 8, 30 and 100% of full sunlight (described as initial light). These saplings were planted in fenced and unfenced plots in a mixed forest in Poland. After six years with no protection from grazing, deer pressure was eliminated by fencing. In this study, we analysed sapling growth and needle morphology five years after deer suppression. Overall, grazing had a negative significant impact on the growth rate and needle morphology of T. baccata saplings. Saplings damaged by herbivores had a height increment approximately one-third that of non-grazed saplings. The grazed yew saplings had a lower needle area and length and a higher specific leaf area (SLA) than non-grazed saplings. Initial and current light conditions did not influence tree growth rates and needle morphology. However, we found positive correlations between sapling height and both leaf area and leaf length and a negative correlation between sapling height and SLA. Browsed yews also had a greater tendency to form polycormic (multi-stemmed) individuals. Lower growth rates, smaller needles and polycormic stems indicate a strategy of "escaping" herbivory pressure even five years after elimination of deer pressure.

Browsing and bark peeling by ungulates is known to affect biodiversity and may constitute the main driving factor of single tree population dynamics. In Slovakia, European yew (Taxus baccata L.) is a threatened species protected by law and present in many protected areas. In the study, we emphasize that protecting land and individual plants may not be sufficient for maintaining of yew populations, unless controlling over damage by deer game is also undertaken. Our results show that in beech forests of the Veľká Fatra Mts, browsing and bark peeling constitute the main negative factor affecting yew seedling-sapling ingrowth transition, and the mortality and vitality loss of adult yew trees. We argue that ungulates may have a larger effect on biodiversity conservation than currently realized.

O Or ri ig gi in na al l r re es se ea ar rc ch h a ar rt ti ic cl le e R Re ev vi ie ew w a ar rt ti ic cl le e S Sh ho or rt t r re ep po or rt t www.plantroot.org 21 Jaloviar P, Kucbel S, Vencurik J, Kýpeťová M, Parobeková Z, Pittner J, Saniga M, Sedmáková D 2018 Underplanted silver fir and common beech cause changes in root stratification and morphology in mature spruce stands. Plant Root 12:21-30.Abstract: In this study we analysed changes in distribution and morphological properties of fine roots caused by underplanting of a 110-year-old Norway spruce monoculture by silver fir and common beech. Three different stand structures were investigated: mature spruce underplanted by beech (S/b), by fir (S/f) and mature spruce with natural regeneration of spruce (S/s). We established 3 sample plots per each structure and took 5 soil cores per sample plot (45 cores in total). Soil cylinders of 5 cm diameter were taken up to 40 cm depth. Fine roots (diameter ≤ 2 mm) were extracted from the soil, classified according to tree species, weighted and scanned; their length and surface were quantified and specific root length (SRL) and specific surface area (SSA) were calculated. Root-to-root interaction of spruce and underplanted species led to differences in vertical distribution of roots towards the more homogenous root density in investigated profile with clear shifting of beech and fir roots into deeper soil layers. Cumulative root fractions of fir and beech in upper 20 cm were lower than those of Norway spruce. The share of spruce roots in depth under 20 cm never exceeded 20%. The co-occurrence of beech and spruce in small spots was about twice as frequent as the co-occurrence of spruce with fir. We found differences in SRL and SSA between broadleaves (beech) and conifers, while the values of beech morphological parameters increased significantly, when mixed with spruce. We assume that the competitive strategy of beech is based in changing its root morphology, whereas silver fir is inclined to extend its biomass.

Abstract:The increasing probability of Taxus baccata (L.) decline given climate change brings forth many uncertainties for conservation management decisions. In this article, the authors present the effects of applying regeneration cuttings since the year 2000 on the viability of the understory yew population. By collecting data from a stand located at the centre of the largest population of European yew in Slovakia, containing approximately 160,000 individuals, and analysing tree-ring records from 38 sampled trees, the improved performance of yews, including stem growth, seed production, and number of regenerated individuals, was revealed. Thinning the canopy by removing 15% of the growing stock volume per decade, combined with the subsequent irregular shelterwood cuttings, was assessed as a useful strategy. Moreover, lower radial growth of females compared to males, but simultaneously their similar response to climate, suggests a possible trade-off between reproduction and growth. Release cuttings of up to 30% of the standing volume in the vicinity of the female trees, executed in the rainy summers following warmer winters, and consistent elimination of deer browsing, can further enhance the positive effects of applied cuts on yew viability. Overall, the suggested active measures could be considered as an effective option to preserve the unique biodiversity of calcareous beech-dominated forests in Central Europe.