Far too close! (Pine Barrens)
In the US, the states of New Jersey, New York and Massachusetts have unusual pine and oak forests that have developed over thick beds of sand. These areas are called ‘pine barrens’.
This collection of images from Pine Barrens illustrates the ‘Far too close!’ approach – that of looking at nature first from a distant perspective and then increasingly closer.
Southern New Jersey has the largest extent of pine barrens. The areas are unlike natural woodlands, because they do not have many types of trees. Mostly the forests are dominated by pine and oak trees. The picture above was taken at a commercial sand pit. The excavation has revealed the thick layer of golden sand. There is barely any brown soil on top of the sand. Soil is made brown by the accumulation of organic matter. On top of the sand sits a thick forest comprised of one type of pine.
This land gets the ‘barrens’ part of the name because early settlers were unable to develop lasting productive agriculture. The sandy soil without sufficient organic content would not retain moisture nor hold nutrients – both needed to support crops. That is, despite first appearances of lush forests, once cleared for agriculture, the land was unproductive – that is, it was barren. The word ‘pine’ is included because the most common trees on this kind of land are pines.
The first three images take the landscape view. As sand is mined commercially in New Jersey, a sand quarry shows that the pines sit in a very thin layer of soil that lies over the thick bed of sand. The second picture (to the left) illustrates the variety of pines in one place. Several species of pine may occur, and some of them, especially the pitch pine (Pinus rigida) often occur in a dwarf state (seen at the front of the group). The final image shows a lush forest that misleadingly suggests to early settlers that the land is very productive.
After these three landscape shots, we move to more individual images that provide us with different perspectives. The first emphasizes the sandy environments in which these trees must establish themselves. The trees in this example are pitch pines (Pinus rigida). Dropped pine needles, resin, cones and pollen enrich the soil around the base of the tree. The next image is of the white pine (Pinus strobus). Later pictures reveal differences between these two species.
In the early nineteenth century, southern New Jersey changed from an agricultural environment to manufacturing activities. The area became known for manufacture of glass, and the discovery of bog iron led to the production of armaments. A system of railroads were put in place to serve industry and fisheries. With time, better iron and coal deposits were found to the south and west. The manufacturing industry declined and many of the railways were no longer needed. The pinelands reclaimed the land that had been taken from them.
The next three images take us closer. All three images show the candle stage which marks the start of the season’s growth. In spring, each branch produces a thick growing tuft, or candle. The candle contains undeveloped needles that grow out during later spring and summer. The needles in the candle may or not be accompanied by young cones. As the season progresses, so the branch gets longer and the pine needles extend, separate and harden. The needles last for two years and then die off and drop. The cones also develop, either to produce pollen or receive it. The picture to the right below is of male cones / catkins.
The male cones produce prodigious clouds of pollen (to the left). Each pollen grain (image to right) is about 1/20th millimeter in width. Two dark wings or bladders help the grain float in the wind. As a result, they may float for long distances. While quantities can be large, there is little evidence that pine pollen is allergenic. Some folk believe it is a valuable dietary supplement.
At higher magnifications, we can see a difference between the female cones of pitch pine (the two pictures above) and the white pine (below). The female cones of the pitch pine are short and dumpy, typically shorter than the needles. The cones of white pine are considerably longer and often much longer than the needles. Young female cones are green, hard, with overlapping scales. After fertilization with pollen, the cones dry out, harden and then the scales open to release seeds.
Pine needles occur in groups. Each species has a distinctive number of needles in each group. In the pitch pine (upper picture to left), has three stiff needles per group. The white pine (second down) has five needles per group. Those of the white pine are longer, thinner, and more flexible. If cut across, as shown below, the shape of the needle differs from one species to another. When the needle starts to grow, it has a basal sheath but this is often shed as the needle matures.
The surface of a needle, as with other leaves, is used to breathe atmospheric gases (carbon dioxide is needed for photosynthesis) and to release (transpire) moisture. The transpiration process draws fluid from the roots to the growing parts of the plant. Gases pass into or out of the leaf through small pore or stomata. In the high magnification image (bottom), the stomata are arrayed in delicate patterns along the needles.
This ‘Far too Close!’ item can be set in the context of ‘Nature’s Envelope’ – the envelope of all things and all processes that make up biology. Biology involves objects from photons to the atmosphere – embracing things that differ by 20 orders of magnitude of size. Processes may be brief events lasting less than a femtosecond, or be the 3.5 billion years of evolution. That is a range of over 30 orders of magnitude of duration. Within this envelope, not all ‘squares’ include biological activities, but about half do (shaded area). The images of the pine barrens open a window that reveals objects from half a kilometer (the section of forest in the sand pit) to the pollen grains that are smaller than one tenth of a millimeter (overall about 8 orders of magnitude). The window provides evidence of events that can be measured in seconds (the shedding of pollen), to those that take hundred of years (large pine trees) – that is the endurance of the processes depicted here range over 10 orders of magnitude of time. The numbers are inexact. Yet, the example illustrates the power of the visual to reveal intricacy and complexity across a wide spectrum of Biology.