Tree was approx. 3 m height. Lower branches with needles in this exposed site.

Trunk at breast height.

Trunk at breast height. Bar is 5 cm. Tree approx.
8 m height. Lower, shaded branches are mostly dead. The difference in height between these two trees is likely associated with the more barren habitat of the shorter tree, rather than age.

Left: needles; bar is 1 cm. Above: growing tip.

Maturing cone. Bar is 1 cm.

Cone with most scales open and seeds released. Bar is 1 cm.

Old cone with uppermost scales not open.
Bar is 1 cm.

Old, serotinous cones. Bar is 1 cm.

Cone scales and seeds from lowermost scales on brown cones. Bar is 1 cm.

Right: Gall-like structures encircling branches were common (also present by serotinous cones in the photo above) are likely due to a rust disease (Cronatium sp.). They "seldom cause serious damage." ^2.

First 3 photos are from Herring Cove backlands, 2007. Growing tip and maturing male cones above. Spent cones from the previous year can remain attached for a year or more (bottom left).

By Suzie Lake, 2008: maturing male cones.

These male cones were largely spent.

Bar is 1 cm.

New female cones. Bar is 1 cm.

Cones produced in the current year and each of two previous years can be observed on this branch. Bar is 5 cm.

Savannah-like stand of jack pine on granitic plateau. Except that it refers to jack pine on sandy soils rather than rock barrens, Eastman's description is apt: "Jack pine must have full sunlight to thrive. Notice that the lower shaded-out branches are frequently dead, through they remain on the tree. Because of this pine's need for sun, so-called jack pine forests are usually quite open, often occurring in "pine plains", savannalike areas of sandy, acid soil." ³

Black huckleberry, broom crowberry, lowbush blueberry, lambkill and reindeer lichens were common understory species.

The defoliated tree in the foreground may have been attacked by Swaine jack pine sawfly, a native pest, which can cause partial to complete defoliation. "The Swaine jack pine sawfly, Neodiprion swainei Middleton, is one of the most important defoliators of pine, Pinus spp., throughout Canada and the Lake States. The larvae are gregarious and feed primarily on older foliage. Numerous outbreaks occur on regular eight year cycles in jack pine, P. banksiana Lamb., stands in Ontario and Quebec. Heavy tree mortality often occurs in stressed, senescing stands."⁴

This tree on a steep outcrop had large numbers of only serotinous cones, mostly in pairs and at most nodes.

On April 30/May 1, 2009, a forest fire ocuured in the region of York Redoubt (Halifax mainland south). Jack pine barrens were notably more completely burned than other, more moist habitats and the fires stopped abruptly at the junction with wet bog vegetation such as leatherleaf. A local resident said that a fire had gone through the same area 44 or 45 years previously. The south mainland area of Halifax, supports large populations of jack pine on exposed, granite rock barrens reflecting, evidently, a history of recurrent fires. Broom crowberry (Corema conradii), another fire-dependent or fire-stimulated species, is also abundant in these areas.

Winged seeds could be observed in and being released from these serotinous cones, apparently opened by the heat of the fire.

Scale is 5 mm.

Barrens outside of the burned area.

Black patches on rock surfaces are areas of [burned] black huckleberry, crowberry and lichens.

Cone and dispersed seeds on burnt ground.

On barrens near Lower Mud Pond. Also present: Corema conradii grown up from rhizomes) and a birch seedling.

Seedling of jack pine. Bar is 1 cm.

Near Flat Lake on Purcell's Cove Conservation Lands. Approximately a dozen jack pine seedlings were present under this burnt tree. Other species;: mostly Gaylussacia baccata (black huckleberry)

A single plant of Artemesia stellariana (beach wormwood) , not observed elsewhere in this area.

Some seedlings appeared severely drought stressed.

A second site near Flat l Lake on Purcell's Cove Conservation Lands.

Other species: Scirpus cyperinus (woolrush), Kalmia angustifolia (lambkill), Gaulheria procumbens (teaberry).

On barrens near Lower Mud Pond. Height of branched seedling in foreground: approx. 18 cm. (This is the same site and erratic as pictured above for Sep. 21, 2009.)

On barrens near Lower Mud Pond. Height of unbranched seedling in foreground: approx. 6 cm.