Glacial maximum

Glacial maximum period that occurred approximately 110,000 to 10,000 years ago. The scientist that study Geology report that around Norway, Sweden, Finland, and north Europe was covered by a thick ice sheet, directly above the current Bothnia Sea the ice layer over land was 2-3 km thick at the max about 90 000 BC.

Glacial maximum depressed the earth, and water eroded it as the glaciers melted. When the glaciers melted they released a lot of fresh water which turned into high inland lake before it was released out to the oceans. The last sight of the glaciers is estimated to have been around 11000 -10000 BC. Some of the antiquity finds in Finland are pieces of pottery, flint; quarts chips at old camp sites are estimated to be 6000 – 8000 old, and other cave paintings that are estimated to be from around 10 000 BC.

The Boreal season was a cool season shortly after the end of the last ice age

About 10 500-8 000 years ago, the early Holocene glacial ice sheet melted away from Europe.
The weather was dry and warm. The temperature was pretty close to the present. In this case, the Nordic countries spread of mixed forests, which were made of birch and pine. Pine became common in the Central Lapland. The Boreal period was drier and more in southern Finland was the end of the period up to 1 degree warmer than the present, and in southern Finland arrived in a warmer climate species of flora.

The Boreal, transitional between the two periods, varied a great deal, at times comprising within it climates like today’s.

Subsequent to the first Blytt-Sernander scheme, the first stage of the Boreal was divided off as a Pre-boreal transitional period followed by the Boreal proper. Before the Pre-Boreal, Eurasia was locked in the chill of the Younger Dryas and was a largely running tundra zone, with regions of taiga, covered with a layer of grasses, shrubs and other small plants typical of vacant land. Large numbers of herbivores wandered in herds over vast distances. The blanket teemed with small, rapidly reproducing species, which supported food chains of larger predators. The largest predators and humans hunted the mammals of the open tundra.

The Pre-Boreal began with a sudden rise in temperature that abruptly changed this ecosystem.

Forest replaced the open lands in Europe. The ancient fauna persisted in Central Asia, but were quickly hunted out, as they were not replenished by the larger areas previously nourishing the ecosystem.

During the Pre-Boreal pollen region IV, large quantities of tree pollen began to replace the pollen of open-land species, as the most versatile and flexible arboreal species colonized their way northward, replacing the ice-age tundra plants. Foremost among them were the birch trees. The trees especially are sensitive to temperature changes and the reaction of moving northward. Almost immediately changes were with the Juniperus nana and Juniper communis, the dwarf and shrub Juniper respectively, which reached a maximum density in the Pre-Boreal, before their niches were shaded out. Glacial maximum left it’s imprint on the Northern hemisphere that the sign can still be seen today.

Sources: Wikipedia.com