Plant Ecology

, Volume 205, Issue 1, pp 23–46

Population ecology of yew (Taxus baccata L.) in the Central Apennines: spatial patterns and their relevance for conservation strategies

  • Gianluca Piovesan
  • Emanuele Presutti Saba
  • Franco Biondi
  • Alfredo Alessandrini
  • Alfredo Di Filippo
  • Bartolomeo Schirone
Article

DOI: 10.1007/s11258-009-9596-1

Cite this article as:
Piovesan, G., Presutti Saba, E., Biondi, F. et al. Plant Ecol (2009) 205: 23. doi:10.1007/s11258-009-9596-1

Abstract

Understanding the ecological mechanisms that allow a species to transition from an occasional understory component to the dominant type in the forest canopy is essential for predicting future shifts in the distribution of species. We investigated this issue with regard to yew, also because mature yew trees have been reported to inhibit self-regeneration and seedling survival, prompting concerns for the long-term preservation of the species. Our objectives were (a) to quantify spatial patterns of yew (Taxus baccata L.) populations near the southern limit of the species’ ecological distribution, (b) to determine the relationships between yew presence and topographic gradients, and (c) to answer the question of how yew regeneration is affected by such patterns and relationships. We analyzed three extensive yew populations (90–165 ha, including 3–12 thousand established individuals) that mostly occupy the understory of beech forests located in protected areas of the central Apennines (Italy). Overall, the realized niche of yew (either as established trees, saplings, or seedlings) followed the expected bell-shaped curve of a species response to an environmental gradient. Yew was mainly found at 1,000–1,600 m elevation on mesic exposures (north and west) and intermediate slopes (30–60%). Geostatistical analysis revealed that yew occurred in patches, as shown by variogram ranges of 40–110 m for yew tree basal area and regeneration abundance. Yew regeneration over the landscape was directly related to basal area of yew trees. At local scales (~10 m), presence of established trees favored regeneration in relatively less developed stands, whereas high density of mature yews suppressed regeneration. Healthy yew populations in beech forests had a minimum size of 0.5–3 ha. As yew density increased within these patches, regeneration dropped, so that yew conservation cannot be limited to presently occurring populations, despite the longevity and potential for vegetative reproduction of the species. Disturbance from grazing and wildfire was also found to impact yew survival. Long-term existence of yew in the Italian Apennines depends on maintaining and expanding old-growth beech forests that incorporate yew patches, and have a minimum continuous cover equivalent to a relatively undisturbed regime (10–50 ha).

Keywords

Geostatistics Gradient analysis Conservation biology Population structure Forest health Forest regeneration Yew 

Supplementary material

11258_2009_9596_MOESM1_ESM.pdf (502 kb)
Supplementary material 1 (PDF 502 kb)

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Gianluca Piovesan
    • 1
  • Emanuele Presutti Saba
    • 1
  • Franco Biondi
    • 2
  • Alfredo Alessandrini
    • 1
  • Alfredo Di Filippo
    • 1
  • Bartolomeo Schirone
    • 1
  1. 1.Dendrology Lab, Department of Environment and Forests (DAF)University of TusciaViterboItaly
  2. 2.DendroLab, Department of Geography, MS 154University of Nevada, RenoRenoUSA

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