Palaeoecology - the ecology of past times.
Ecology is the study of the interconnected web of the natural world and embodies all energy and resource inputs and outputs. Theoretically there is only one ecosystem, the global or even universal ecosystem. However we often break the environment being studied up into smaller, more manageable ecosystems, maybe a desert, a bog, a pond or lake, a mountain range. This becomes more problematical in determining the edges of such ranges.
A lot of the focus of living organisms in palaeoecology is on plant life – plants don’t move like animals, they are more indicative of the long term environmental conditions and as such successful plant growth is a proxy for the environment. They shed parts during their lifetime – leaves, seeds, pollen or spores, branches – which may be incorporated into sediments as fossils.
There is a fundamental difference between ecology and palaeoecology, though ecological analysis and understanding underpins them both. That difference is time.
Ecology embodies the study of the earth systems of now, environments and populations, behaviour and habits that can be observed and measured. However change, particularly slower rates of change – the growth of trees, the spread of populations, the accumulation or erosion of sediments, changes in weather patterns and climate – is harder to measure, requiring long time series of observations. Even with these analysis requires the assumption of the direction of change. Increasingly warmer weather patterns over a number of years may represent a change in climate; it may equally represent fluctuations within accepted limits and just be an aberration. A fourth year of cold weather may alter the conclusion – and the longer the time series of observations, the more certain of the direction of change.
In palaeoecology direct observation of living systems is severely restricted to the small part of the environment that has been preserved, either as fossil remains of living organisms, sedimentary structures, isotopic proxies for climate or atmospheric conditions. But the changes that occurred over long periods can be observed from these clues, and predictions that are so hard in ecology are laid bare to view in palaeoecology.
The palaeoecology of West Cork has been divided into time slices :-
see the menu on the left sidebar.
The Most Ancient Days - Devonian Palaeoecology
The oldest rocks that outcrop in West Cork date from the Devonian period, between about 390 and 350 million years ago; a time when life forms really started to take a major hold on land, to such a degree that the atmosphere changed, rates or erosion and weathering changed, sea levels changed. At that time the piece of earth's crust that was to become West Cork lay just south of the equator, on a small piece of crust that had recently joined on the side of a big continent, and was later to be squeezed by another piece of crust. A time of deserts, flash floods, wadis, volcanic eruptions and ash falls
The Missing Link – Mesozoic and Tertiary Palaeoecology
The most extraordinary thing about the following 300 million years is - there is little trace. Sediments that were deposited have been eroded away out of existence. But it is possible yo use clues from elsewhere to have a guess at what was happening in West Cork.
The Ice Ages - Quaternary Palaeoecology
Like the rest of the northern hemisphere, which is where West Cork was located by now, the Quaternary period that Covers most of the last 2 million years was a time of expanding and contracting ice sheets, glacials and interglacials. The effect of the ice ages that covered Ireland, and West Cork, was to wipe the slate clean of all sediments, and the formations, fossils, and traces that they contained of environments that went before. Unless such records had been secured in rocks, or buried deep, they were scraped aaway by ice sheets 1000 metres thick. But the last glaciations to cover West Cork left their mark that are still visible today, shaping the landscape we seearound us to a degree that is surprising, shocking, and exciting.
Warming up in the Post Glacial - Holocene Palaeoecology
The Holocene is the period from the end of the ice age, the final retrest of the ice and the warming of the climate, until the present day. It has been sugegsted that we are now in a new age, the Anthropocene, the Age of Man. Maybe that is a bit