Forest Succession

The Redwoods forest is home of one the tallest and oldest trees. Some redwoods can live to be 2,000 years old and can grow over 200 feet tall and 16 to 20 feet in diameter. 96 percent of the old growth forest has been logged

Similar information has been explored in different studies. A previous study conducted showed that trees with smaller DBHs and greater canopy coverage allowed for an increase in species richness (Rannius T 2000). Furthermore, researchers have found that saplings across different species like the sugar maple exhibit greater growth in open canopies than saplings that are in closed canopies (Canndam C. 1998). Although these studies are important, the relationship between canopy size and DBH is still yet to be explored. In response to this lack of knowledge, we have conducted a study to further explore this correlation. Our hypothesis is that the larger the DBH size, the greater the amount of canopy coverage in a given area for the tree being studied.

Every forest has a story to tell. By looking closely at its habitants, that story can be interpreted. Much of this narrative is written in the trees: their age, their tolerance to shade, and the rate at which they grow are all characteristics that can imply a lot about their environment. Exploring these relationships and how they connect with each other can indicate the health and history of the land. Heiberg Forest, located in northern New York, was once used for agricultural purposes in the 1800-1900’s. (Nowak, Lecture Notes) Much of the land once used for farming was left to regrow back into a young forest. The life history of different tree species can be determined by examining the most common species in Heiberg.

Under the soil of the forest there is a huge layer of redwood roots. Roots from a redwood tree may only grow 3 feet down but they can grow up to 20 feet out away from the trunk of the tree. The roots of many redwood trees are grown together any many times, when a tree starts to lean, the thick layer of roots can hold it up. When redwoods start getting cut down this can ruin the layer of roots that covers almost all of the forest. Then redwood trees would not have much support as they do and would be more inclined to fall over. Cutting down redwoods would also lower the chance of reproduction. Redwood trees only reproduce every so often, this process could take over five years. First the redwood drops acorns that fall to the forest floor. Then after some time, a larger type or acorns is dropped and releases pollen which pollinates the first acorn (Hemmerich 2014). Many of the seeds do not grow at all. Only about one in every 200 seeds will grow and become a full sized redwood tree. Of course this process does not happen overnight, it can take up to 100 years for a seed to grow and become a mature redwood tree (Hemmerich 2014).

The topography of the island is also of note. The west end of the island features a closed-canopy forest with more hardwood trees. The east end of the island is better characterized as a “boreal forest,” a term used to describe regions that are mostly covered by coniferous forests. It is good to note that the balsam fir is found on both ends of the island, but that samples used in the study from the west end of the island were, on average, older, but shorter, than those samples found on the east side of the island.

B. Retaining individual high value trees--for bear dens, raptor nests or as an example of old growth

There are many factors that account for the changes to the vegetation over time within ecosystems in the British Isles, such as human activity, climate, soil, light availability and intensity and natural disasters. The characteristics of the vegetation that are influenced by these factors are height, distribution, variety of species, adaptations and density of the vegetation. Some of these factors have relatively little influence on the succession development, whereas others have a dramatic influence over a long period of time, such as human activity. These factors, over time, result in the progression of a succession until the climatic climax vegetation is reached. However, sometimes these factors can mean that a plagioclimax is reached,

Walking into the primary woodlands of the Heiberg forest you immediately notice the immense amount of plant diversity. Along the trees I was able to spot different types of ferns that blanketed the small mounds of dirt, which were also home to enormous sugar maple trees. The bumpy nature of the ground proved that the land I was walking on had not been clear-cut and plowed, but, strangely enough, left alone. As we continued along going deeper into the forest, the slight elevations in ground level began to smooth out, and the amount of plant diversity decreased and changed from sugar maples to spruces. Not only was there a difference in species, but the order in which the trees were planted gave way to the secondary woodlot. The height of trees was noticeably different, which can have effect on the species closer to the surface. Due to the high demand in the northeast for agricultural and logging purposes, the structure and composition of the Heiberg forest has changed considerably. Early colonialism in America resulted in deforestation of the land in order to provide the imperialistic Europe with the resources they desired. This desire most likely stemmed from the overuse of their own land.

"Selective cutting" is the practice by which trees are cut down according to certain ascertainable features. If a tree were so old and large that

The medieval woodland is older than Savage’s Wood, which the earliest record of is from 1880, and has an area of 32-hectares. It’s traditional management of coppicing and pollarding ensures that the indigenous vegetation continues to grow and like Savages Wood, the canopy is dominated by oak and hornbeam, however it also has a broader biodiversity with other trees such as heather grow and dog’s mercury. In addition to this, King’s Wood also has a wide range of moss and mushrooms. The Bedfordshire woodland is an example of the indigenous temperate deciduous woodland of the UK, and due to it’s ancient status, it has over 250 species of plants and a large variety of wildlife than Savage’s Wood. However, it proves that Savages Wood is an example of an indigenous temperate deciduous woodland of the UK to an extent as there are many similarities; both woodlands have a similar stratification of the canopy, the shrub layer, the undergrowth and the litter layer. Also, similar plant species are found at both sites, with oak, ash, beech, hornbeam and wych elm being

The dynamics of the forests changed with the introduction of the Europeans. The frequent grass fires were eliminated after a hundred years of cattle and sheep grazing. This meant that brush was able to accumulate and more seedlings and fire intolerant trees were able to mature. The Europeans also utilized the wood resources that surrounded them. Extensive logging in areas, removed all the best Ponderosa pines leaving the area virtually clear-cut. This opened area allowed more seedlings and saplings to mature because there were no

The host, stress, and pathogen hypothesis describes decline as a disease. This theory suggests that some form of environmental stress alters the host tissues making it vulnerable to pathogen invasion. The pathogen thus invaded weakens the plant tissues leading to tree decline (Ciesla and Donaubauer, 1994). The synchronous cohort senescence hypothesis considers decline as a part of forest dynamics involving various interacting factors. This concept considers that certain sudden eliciting environmental factors such as drought and flood predispose the trees to pest and pathogen attacks (Ciesla and Donaubauer, 1994).

The F-test values in canopies (0.031271512) and sub-canopies (0.005008424) are both below 0.05 so we can say with 92% confidence that the canopy structures in burned and unburned areas differ and with 97% confidence that the sub-canopies vary between the burned and unburned areas. Unburned areas tended to have better developed structures of canopy and sub-canopy trees because they were given more time to accumulate compared to recently burned areas which have recently undergone a disturbance. The F-test value for DBH (0.022472008) is also below 0.05 so we also have to assume that there is variance in terms of DBH in burned and unburned sites. Unburned sites have larger trees (larger DBH) because these trees had more time to grow compared to trees in recently burned sites. Since the F-tests values for the logs (0.076083352) and shrubs (0.340469754) were calculated to be above 0.05, we are not able to draw definitive conclusions on this data, therefore we have to assume that the logs and shrub structures did not vary within the burned and unburned sites (Klowden et al. 2015). Succession is evident in this experiment as there is an overall greater percent coverage of grasses, woody plants, and annuals & perennials in burned areas compared to open space. Open space is greatest in unburned areas and there is more open space in unburned areas than burned areas; this is mainly because the woody plants in unburned areas store lots of nutrients within themselves, therefore having less grasses and smaller plants on forest floors (Dickman et al 2014). Five different species of canopy trees were identified in unburned sites compared to only three species of canopy trees identified in burned sites which allows me to conclude that there is more diversity in the species of canopy trees in unburned areas than burned areas. There may have been more types of species found in unburned

The density of trees from 60% to 50% shows a significant change in the percentage burnt as well as ticks. The average percentage burnt for the density 60% was 66.9% whereas for the density 50% the percentage burnt was an average of 1.5%. This

Reforestation is the building up of forests or woodlands that had once existed, but have been subjected to damage or have even been destroyed. Some forests are able to grow back naturally if there are enough trees nearby that can send their seeds out either by animals or wind. Forested areas that have been severely damaged are very unlikely to grow back naturally and need to be replanted and replenished by human influence. Many conservation groups have joined together in an effort to replant trees (www.urbanomnibus.net). Even though reforestation can be done by nature over a long period of time, help from humans also can work, or just a combination of both can also accomplish the task.