GEOLOGIC ORIGINS AND VEGETATION INFLUENCES

New Jersey's Pinelands National Reserve is located in the Outer Coastal Plain, the largest of five geologic provinces in the State (see Geologic Provinces map, page 219). These five geologic provinces are called: (1) Ridge and Valley, (2) Highlands, (3) Piedmont, (4) Inner Coastal Plain, and (5) Outer Coastal Plain.

Geologic changes in the earth's surface and climatic changes that have occurred over millions of years coupled with man's more recent activities have determined the kind of vegetation found in New Jersey's Pinelands today. Five natural factors that are of major importance to the trees, shrubs, and herbs found in the region are: (1) porous sandy soil, (2) acidic water, (3) low nutrient levels in soil and water, (4) frequent fires, and (5) climate.

GEOLOGIC ORIGINS

It has taken millions of years to create the Pinelands as we know them. There are five major time periods in the development of this region. (1) About 100 million years ago the sea covered the land leaving deposits of clays, silts, sands, and gravels. (2) Then, about five million years ago, the sea withdrew from southern New Jersey and the land rose. (3) Approximately 1.8 million years ago glaciers moved south and at least three major ice advances reached New Jersey. The last of these, the Wisconsin, came farthest south, but stopped 10 to 40 miles north of the Pinelands. This ice began to retreat about 10,000 years ago. (4) Within the last 10,000 years, plant populations that we recognize in the Pinelands today began to develop. Terrestrial (uplands) plant species have adapted to the region's frequent fires and often sandy soil that has low nutrient content and low water holding
capacity. Aquatic (lowland) plant species have adapted to acidic water (water with a pH less than 7) and low nutrient levels. (5) During the last 300 years, from early European colonization to the present, man's activities on the land including construction, sand and gravel mining, lumbering, and farming have had an impact on the Pinelands. For example, it has been estimated that by 1980, most cedar swamps in the region have been clear cut five to seven times.

SANDY, NUTRIENT POOR SOIL

Today, most soils within the Pinelands are very porous, due to the relatively large size of the sandy particles. The soil's surface is often dry, acidic, and contains few earthworms and microorganisms. As a result, forest litter accumulates and does not readily decompose. This prevents soil enrichment and the formation of fertile topsoil.

ACIDIC WATER

Rain water quickly moves downward through the sandy, highly permeable soil carrying dissolved minerals with it.
This rapid movement of water containing dissolved minerals is called leaching. By contrast, Pinelands surface streams are slow moving and shallow because the land is relatively flat. Adjoining these highly acidic streams are vast areas of marshes, bogs, and swamps. Such places are known as wetlands.

FREQUENT FIRES

The dry, upland forest floor provides excellent conditions for fires. From the earliest time of human habitation, when it is believed the Indians burned the forests to improve hunting conditions, up to today, Pinelands history has always been associated with frequent, severe fires. Much of the region's upland vegetation has developed adaptations to survive fire. Pitch Pine, for example, has thick bark and can sprout from tree trunks and protected buds within the root system (see Pitch Pine Adaptations, page 206 ). In fact, frequent fires favor the growth of pines over oaks.

CLIMATE

Plant populations that are found in the Pinelands today developed in the last 10,000 years. Climatic change has been an important factor in this process. Warming trends have resulted in the northern migration of southern species while cooling trends have brought more northern species southward. The advance and retreat of glacial ice, like the Wisconsin, has influenced cooling and warming trends. The Atlantic white cedar is an example of a tree species thought to have migrated northward to the Pinelands during a warm period.

HUMAN INFLUENCE

The landscape of the Pinelands has undergone continual disturbance. There is perhaps not a single acre which has not been burned or cut. Since colonial times, pine wood has been a most important industrial fuel. For example, hundreds of square miles of forest were repeatedly cut to supply fuel for
the furnaces of the local glass and iron industries. Oaks were used in shipbuilding and for home heating. Vast stands of Atlantic white cedar were cut for lumber, posts, and shingles. Today, lumbering continues on a much smaller scale.

Within the century, New Jersey's cranberry production has expanded. Lowlands have been cleared and stream courses diverted as bogs have been developed. Additionally, blueberry cultivation began at Whitesbog in Pemberton Township, Burlington County in 1916 and has grown steadily to make New Jersey the second largest cultivated blueberry producing state in our nation.

These conditions --porous sandy soil, acidic water, low nutrient levels in soil and water, frequent fires, climate, and human activity--have influenced the vegetation that thrives in New Jersey's Pinelands today.