ROBERT SMITH ON PLANT ASSOCIATIONS OF THE TAY BASIN. 205 
exploited, and many of the trees have probably been planted by man, 
although many good-growing seedlings are to be seen springing 
up spontaneously. But, from what we know of the former forest 
conditions of Perthshire, the oak must have been very common, and, 
from the healthy condition of the trees in their present situation, we 
can assume that these woods represent part of the native vegetation 
of the region. 
In Scotland the oak rises to a greater altitude than the beech, a 
fact quite in keeping with its latitudinal range, which extends further 
north than the beech. But on ascending the Alps we find that, 
contrary to our expectations, the oak ceases at a lesser altitude than 
the beech. The most probable explanation, adopted by M. Christ, 
is that the more fleshy leaves of the oak are less able to withstand the 
great torrential summer-storms which occur in those regions. 
The contrast between the beech and the oak associations is 
striking, and is directly connected with the lesser shade of the latter 
tree. More trees are found freely mixed with it, and an undergrowth 
of shrubs—absent in the case of the beech—is very characteristic. 
In the list of plants associated with the oak the woody vegetation 
is given apart from the herbs to show its relative luxuriance. The 
vegetation is much richer than that of the beech woods, and the 
number of “shade” plants fewer. We still, however, find species 
which vegetate and flower early, before the overshadowing trees have 
sprung into leaf. In the lighter parts, and where the soil is poor, 
heather and juniper may obtain a hold, and introduce the moor 
vegetation. 
The following list of the oak associates has been compiled from 
notes of the species observed in various oak woods between Dunkeld 
and Pitlochry, and has been compared with those of the Trossachs 
and Abeifoyle districts :— 
PLANT ASSOCIATION 
OF THE OAK COPPICE. 
Arborescent Vegetation. 
Ilex aquifolium, L. 
Prunus avium, L. 
Pyrus Aucuparia, Ehrh. 
Crataegus Oxyacantha, L. 
Fraxinus excelsior, L. 
Ulmus montana, Stokes. 
Betula alba, L. 
Alnus glutinosa. Medic. 
Corylus Avellana, L. 
Fagus sylvatica, L. 
Rubus idaeus, L. 
R. fruticosus, L. 
Lonicera Periclymenum, L. 
Vaccinium Myrtillus, L. 
Calluna Erica, D. C. 
Erica cinerea, L. 
Myrica Gale, L. 
Juniperus communis, L. 
herbs. 
Anemone nemorosa, L 
(In wet spots.) 
Shrubs. 
(Isolated examples.) 
Populus tremula, L. 
