the plant life in the quaternary period?

Answer 1

Generally speaking all the above are correct, except the Quaternary Period consists of the Pleistocene Epoch, which includes all of the Quaternary, except the last 10,000 years, which is called the Holocene or Recent Epoch. The Pleistocene Epoch is more or less equivalent to the Great Ice Age or Ice Age. The Holocene Epoch includes the interval since the end of the Ice Age.

Quaternary paleobotanists generally divide plant fossils into two categories: those you can see with the naked eye called plant macrofossils, and those you must examine with a microscope, called plant microfossils.

Plant Macrofossils
Macrofossils are those plant bits with which people are most familiar and which would immediately be recognized in a sediment exposure. You might expect to find pieces of wood, seeds, fruits, cones, leaves and needles. Most often macrofossils become buried and preserved in peat, clay or silty sediments deposited close to the original plant communities. Floodplain, delta, lake and wetland derived strata contain the best macrofossils. In wetland settings such as bogs and swamps, the plant parts simply fall to the wet ground, where decomposition is slow or absent, and become buried by further plant parts and occasional mineral sediments. In lakes plant macro-remains fall into the basin at the edges, are blown in by wind or washed in by streams. Parts of aquatic plants, in particular, fall to the lake bottom becoming entombed in the ooze. Floodplain and delta environments often preserve great quantities of plant remains especially wood. You need only to visit a floodplain or delta during the spring or summer flood stage to see how much wood is washed into, and flushed through a drainage to be dumped onto, and buried in the lower reaches of a drainage system. These sediments are exposed as sea levels and lake levels drop and deposits are cut into by watercourses and by waves.

Aside from normal sediment burial of macrofossils, there is the peculiar preservation of plant bits by woodrats (commonly called packrats) in middens and nests. In British Columbia, bushy tailed woodrats (Neotoma cinerea) construct nests and produce middens of plant debris, all cemented together by solidified amberat, the concentrated urine of the rats. In dry climates, like those of the southern Interior of B.C., the plant material in the middens and nests preserves perfectly. Needles, seeds and other parts are removed by soaking the middens in warm water. So far B.C. middens have yielded plant remains only a thousand years old, but similar middens in the southwest United States, reach back to more than 20,000 years ago.

Plant Microfossils
Microfossils are tiny, but recognizable, bits of plant matter such as pollen grains and spores, enclosing walls of algae and fungi and remains of microscopic animals, all invisible to the unaided eye, but easily recognized in a microscope. Of the two plant fossil categories, microfossils are the most ubiquitous and most informative, occurring in many kinds of sediment. Just imagine how much pollen blows around every year, and you can appreciate that on almost every bit of British Columbia's surface falls at least one pollen grain or spore. As long as there are sediments with the right chemical make-up to bury that pollen grain quickly, it will be preserved and eventually can be dug up and discovered.

Microfossils occur in thousands of different forms. Most common are:

1. pollen grains produced by advanced vascular plants (mainly flowering plants and conifers),
2. spores produced by many groups of primitive plants,
3. reproductive structures of fungi and
4. numerous walls of microscopic algae. In some cases there also remain certain resistant parts of large plant pieces, such as leaf hairs and other leaf surface structures


Pollen grains are the male reproductive bodies of advanced plants. Their remarkable outside walls are composed of a nearly indestructible substance called "sporopollenin", which ensures the preservation of these bits under many kinds of circumstances. Even though the living insides are eaten by other organisms, the sporopollenin coat survives.
Most importantly, different types of plants produce different types of pollen grains that can be readily identified . Pollen and spores have distinctive shapes, size, structural features and especially sculpturing. Many coniferous trees, such as pine and spruce, produce pollen with floats or bladders. Several types of deciduous trees produce pollen grains with openings or pores.

Not only does the basic structure of pollen grains vary, but so do its surface features . For example pollen of hardhack (Spiraea douglasii) of Rose Family plants often bears numerous ridges. Using images of 8,000-year-old hardhack pollen obtained in a Scanning Electron Microscope, grad student Greg Allen and I discovered that this swamp species grew in the bottom of what is today a lake on south Vancouver Island. Swamp plants cannot grow underwater in the bottom of lakes, so the climate must have been much drier than it is today.

Like pollen grains, spores and other reproductive units of primitive plants and fungi vary distinctly in basic form and in sculpturing. Some are kidney-shaped, whereas others bear prominent three-armed marks. Microfossils from algae come in a variety of curious but distinctive forms too. Two publications Pollen Analysis (P.D.Moore, J.A.Webb and M.E.Collinson, 1991) and Textbook of Pollen Analysis (K. Faegri and J. Iversen, 1975) describe many of the concepts and methods of plant microfossil analysis.

Like macrofossils, microfossils preserve best in peats, clays and silts. However microfossils survive in organic soils too and if those soils become buried, the microfossils will be preserved. Unlike macrofossils that are concentrated near the source of the material, microfossils, because of their tiny size, can be transported to, and preserved in any part of a body of water including the middle of large lakes and the bottom of the ocean.

To find and study microfossils you need a microscope that will magnify your sample 400 times life-size. You might first try to collect living pollen from a tree and put it in water on microscope slide, squash it with a thin cover slip and look at it under the microscope. The outline of the pollen grains should be visible, although the inside may contain living tissue.

To see fossil pollen and spores, obtain a sample of muck peat from a swamp or bog, or plunge a stick or tube deep into the muck at the bottom of the lake. Smear a bit of the muck from the retrieved stick onto a microscope slide, put on a cover slip and examine it under magnification. If the material under the coverslip is spread thinly enough, you should see lots of microscopic plant debris, including pollen grains, among the finer particles. Normally we use a series of strong chemicals to remove all of the fine debris, leaving behind mostly pollen and spores.

Finding Quaternary plant fossils
Microfossils occur almost anywhere where there is sediment. Every lake, swamp, bog, fen and year-round wet soil collects microfossils, and has been doing so for more than 10,000 years. Even limy travertine or tufa deposits around hot springs, and debris in caves may contain preserved microfossils. In almost all of these situations occur the "Mickey Mouse" hat-shaped pollen grains of some of our very common conifers such as pine (Pinus), and spruce (Picea) . The pollen of these trees travels great distances because of the bladders or floats attached to the main body. Conifer pollen of this kind occurs not only in Quaternary sediments, but also in rock as ancient as the Permian.

Macrofossils occur in the same settings as microfossils, such as lake and bog sediments. However getting good samples of macrofossils is generally more difficult than getting microfossils because exposures or special coring equipment are needed. The most accessible sites are traditional geological exposures such as excavation faces or river banks and cliff faces. Just like older fossils exposed in rocks, plant macrofossils are exposed in soft sediments from which they can be dug or hammered out. In some circumstances the fossils are washed out with a hose.

In British Columbia the chance of finding Quaternary macrofossils is greatest along the sea coast. In this setting, waves erode cliff faces, exposing beds with macrofossils. Occasionally waves slowly expose macrofossil beds in the intertidal zone as they cut a platform. Several such situations occur on the south end of Vancouver Island where plant beds several thousand years old crop out in the intertidal zone. Sometimes the stumps of ancient forests can be seen emerging from the beach surface. If you clear away the thin layer of sand and gravel over the plant beds, you may even see remnants of the ancient forest floor.

What Quaternary plant fossils tell us
Quaternary plant fossils, especially pollen and spores, provide one of the most powerful tools for understanding the history of terrestrial ecosystems and the processes that shape them. Any change of the landscape results immediately in a change of the plant species which grow there.

Climate is the primary factor that controls the vegetation. Thus Quaternary plant fossils document the changes in climate during a time of dramatic and major climate change. During this time of uncertainty concerning future global climate, many scientists study Quaternary microfossils to understand the processes and rates of climate change. Simply documenting the history of vegetation in a region provides insight into the origin and longevity of ecosystems. For example, although much of the coast of British Columbia is covered today by similar cool temperate coniferous rainforests, those rainforests arose in different ways from region to region.

Micro-and macrofossils studies also tell us when various plant species came to the province and by what route. For example although all the major tree species of south Vancouver Island have been there for at least 10,000 years, Garry oak (Quercus garryana) did not arrive until 7,000-8,000 years ago.

Microfossils provide insight into changes in landforms too. Pollen analysis of peaty silts and clays along the coast reveal distinct golf-ball like pollen grains of the Goosefoot and Amaranth Families . These pollen grains originate from plants such as saltworts (Salicornia spp.), which grew in salt marshes and indicate the position of higher sea-levels since the last glaciation.

Quaternary vegetation of British Columbia
Most of Quaternary time is poorly represented by plant fossils with many sites and studies recording only the last 15,000 years. Nevertheless we know that the plants from the Quaternary more or less resemble those growing in B.C. today. However their distribution has changed frequently and dramatically.

Our only insight into the first half of the Quaternary comes from sediments near Dog Creek, British Columbia studied by Glen Rouse and Bill Mathews, emeritus professors of the University of British Columbia. A wide range of pollen grains from conifers and flowering plants are preserved within these deposits. Pine, spruce, western hemlock, true fir and larch conifer types occur in combination with alder, birch, sage and especially goosefoot-type pollen. A variety of fern spores are also recorded. Despite the diversity of conifers, the vegetation is interpreted to have been tundra-like, confirmed by its association with glacial features.

Another peek into Quaternary environments comes from the study by Neville Alley and Stephen Hicock, from the University of Western Ontario, of sediments exposed in sea cliffs near Sooke on Vancouver Island. These are interpreted to represent an interglacial interval, perhaps the last one, called the Sangamon Interglacial in North America. The earliest layers record abundant Douglas-fir pollen and suggest a grassy floodplain bounded by dry hills covered in nearly pure Douglas-fir stands with cedars and western hemlocks in moist settings. As is often the case with the interpretation of fossil assemblages, Alley and Hicock provide an alternative interpretation -- that of stands of Douglas-fir scattered across a grassland on dry gravels, with cedars in sloughs of the floodplain. Cones of Douglas-fir, western redcedar and Sitka spruce from the beds confirm the tree species present. Later in the interval, moisture favouring species such as alder, western redcedar and cattails and yellow pond lily recorded expansion of wetland environments.

Several exposures from the Fraser Lowland and the east coast of Vancouver Island reveal life during the major non-glacial interval -- about 30,000 to 50,000 years ago -- that preceded the last series of ice advances. Stephen Hicock and I discovered that clubmoss, grass and diverse herb pollen and spores at the start of this interval indicated treeless terrain similar to alpine and subalpine meadows occupied the area as the interval began. Soon thereafter, lodgepole pine woodland, followed quickly by spruce and mountain hemlock forest, covered the land. About 40,000 years ago the forests consisted of western hemlock, mountain hemlock and lodgepole pine and grew under a moderate, but moist climate. This climate was not quite as warm as it is today however. Soon thereafter the climate cooled, western hemlock declined and spruce and mountain hemlock prevailed. At the end of the interval cold meadows returned as glacial ice began to build up again.

Several sites, again mainly from southwestern B.C., reveal that from 30,000-20,000 years ago the landscape was covered mainly by open plant communities. For example Rolf Mathewes of Simon Fraser University showed that at today's site of the University of British Columbia abundant sedge, grass and herb pollen indicated sedge-dominated wetlands on a floodplain with rich and diverse herbaceous communities on higher land.

Sediments containing both macrofossil and microfossil remains from Port Moody provide a brief glimpse of plant communities and conditions 17,000 to 18,000 years ago, just before the last great ice sheet buried us in the deep freeze. Subalpine fir and spruce forest and parkland covered the area revealing that cold humid continental climate predominated, the mean annual temperature must have been about 8°C colder than today and the tree-line depressed by 1200-1500 m. Abundant needles of Pacific yew revealed that this relatively uncommon tree formed extensive thickets. The discovery of the distinctive Pacific yew needles was particularly fortunate because pollen of Pacific yew is rarely found.

Investigations of sea cliff exposures on Graham Island in the Queen Charlotte Islands provide an insight into conditions at the time ice covered much of British Columbia. According to Rolf Mathewes, who has spent many years studying sites on the Queen Charlotte Islands, patchy meadows and bare soil covered the land from 16,000 to 13,000 years ago. Seeds and pollen were recovered providing exceptional insight into the diversity of herb types including a member of the Pink Family (Caryophyllaceae), dock (Rumex) and pearlwort (Sagina). Microfossils and macrofossils such as net-leaved dwarf willow (Salix reticulata) of this interval and slightly later show that plants typical of alpine environments once grew near sea level and the climate was likely much colder than today.

Studies of lake and bog sediments reveal the history of our landscape since the melting of the last ice sheets. Pollen and spores are identified and counted from a series of samples representing levels in a core or exposure . Along the coast lodgepole pine woodland and forest predominate during the first 2000 or so years. The east side of Vancouver Island seems to have been more open than other regions. Near Sidney, large now-extinct bison roamed a landscape that may have been covered in aspen groves. At the same time the southern interior of B.C. was open, possibly covered by sage, grasses and scattered mixed shrubs on upland sites. Cattails and sedges grew in some of the lake and pond basins. The first tree to appear at several of the sites may have been aspen. Notably large glacial lakes and masses of ice remained in the heart of the Interior Plateau. Conifers, predominantly pine, only began to appear between 10,000 and 11,000 years ago.

About 10,000 years ago major rapid warming brought about significant adjustments in the vegetation. On the southern coast Douglas-fir, recognized by its distinct sphere-like pollen , spread along the coast becoming a major forest element as far as north Vancouver Island. Familiar conifers like western hemlock and spruce were there too from 10,000 to 7000 years ago, but played different roles than today. For example, spruce, assumed to be Sitka spruce, was a major forest species on north Vancouver Island, whereas western hemlock was much less abundant than today. On the south east side of Vancouver Island there may have been little forest cover at all, rather grasses and wildflowers predominated. Western redcedar, now a common coastal tree species seems to have been only a minor constituent of forests.

East of the mountains the early Holocene was a time of hot and dry climate. Many of the valleys were covered in grassland or sagebrush. Open vegetation likely extended up the slopes into today's alpine zone. Many small lake basins held little or no water, being no more than seasonal ponds. Today's principal conifer species grew in the region but mainly at high elevations or on moist north-facing slopes.

Between 7000 and 4000 years ago forest composition changed and the area of open terrain shrunk. On the coast, first western hemlock and later western redcedar expanded, at the cost of Douglas-fir and spruce. Lake basins began to fill with water and wetlands expanded. In the rainshadow of south Vancouver Island, Garry oaks formed a major part of the tree cover. Increased moisture and cooling encouraged the forests to expand down slope and into mid elevation valley bottoms in the interior of British Columbia. Hot and dry grassland and sagebrush plant communities shrunk. Lakes deepened and expanded and the landscape took on an appearance much as it does today.

Until recently plant macrofossils and microfossils helped us reconstruct Quaternary environments for intervals of hundreds of years or more. The excavation of sediments at Heal Lake near Victoria, Vancouver Island revealed thousands of superbly preserved logs , some nearly 10,000 years old. Every year a tree grows it lays down a ring. Features of that ring provide significant information about climate and other events on an annual basis. It is likely than most lakes in the coastal and interior regions of British Columbia contain equally great troves of ancient wood although they will not be easily accessible. Through the study of logs from Heal Lake and perhaps others we may learn to understand climate and climatic processes in a way and on a detailed scale never before possible in northwestern North America.

Answer 2

Quaternary Period Plant Life

Answer 3

The Quaternary (epoch) is an outdated term that still clings onto life in modern Geology. The more correct term would be The Recent. As for the life in that time frame, just look around at the plant life you see today, because the quaternary is going on right now.

Answer 4

We're in the quaternary. It was cooler and drier at the beginning of the quaternary, so a lot of land had more scrubby plants and grasslands.
But the quaternary is what you see now. So, anything that is present counts.