Archive for January, 2021

Pinus yunnanesis

January 16th, 2021 No comments

In the Yunnan Province of China, P. yunnanensis occurs in two growth forms: as a tree (var. yunnanensis) and as a shrub (var. pygmea) [1]. The shrubby form occurs mainly in upper slopes and ridges (Fig. 1), where soils are poor and dry, and fires are likely. This shrubby pine is very interesting and quite unique among pines: it has serotinous cones (Fig. 2), and resprouts after fire from basal buds (Fig. 3), generating multi-stemmed shrubby pine populations [1]. Serotiny is common among pines [2] while resprouting is not [3], so pines with both serotiny and resprouting are rare; and having a multi-stemmed growth form is even rarer.

Fig. 1. Pine shrubland (Pinus yunnanensis var. pygmea) in Yunnan, China. Photo C. Luo [1]
Fig. 2. Pinus yunnanensis var. pygmea showing serotinous cones, Yunnan, China. Photo: W.-H. Su [1]
Fig. 3. Pinus yunnanensis var. pygmea resprouting from basal buds after a fire, Yunnan, China. Photo: JG Pausas [1]


[1] Pausas JG, Su W-H, Luo C, & Shen Z. 2021. A shrubby resprouting pine with serotinous cones endemic to Southwest China. Ecology [doi | pdf]

[2] He T, Pausas JG, Belcher CM, Schwilk DW, Lamont BB. 2012. Fire-adapted traits of Pinus arose in the fiery Cretaceous. New Phytol. 194: 751-759. [doi | wiley | pdf | suppl.]

[3] Pausas, J.G. 2015. Evolutionary fire ecology: lessons learned from pines. Trends Pl. Sci. 20: 318-324. [doi | sciencedirect | cell | pdf]