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Paleoecology & Paleoenvironment

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UNIVERSITI MALAYSIA KELANTAN
EGT2023- PALEONTOLOGY
TOPIC:
GROUP ASSIGNMENT:
PALEOECOLOGY AND PALEOENVIRONMENT ESSAY
SUBMITTED TO:
DR. NURSUFIAH BTE SULAIMAN
PREPARED BY:
SEMESTER 3 SESSION OF 2021/2022
1.0 INTRODUCTION
Definition of Paleoecology
Paleoecology refers to an ecology of the past which is the study and understanding of
the relationship between organisms and their environment. It is because the past
organisms and environment could not be watched directly, much paleoecological
research is concerned with determining past occurrences, distributions, and abundances
of organisms and reconstructing past populations, communities, landscapes,
environment, and ecosystems using geological and biological evidence. Paleoecology
can be studied by everyone in any period of Earth’s history in which life was present.
However, the main parts of paleoecology to ecology are from the most recent geological
interval, the Quaternary period, covering the last 2.8 million years. The emphasis of
this article is on Quaternary paleoecology because of its strong links with contemporary
ecology. The research approaches and philosophy of paleoecology are outlined and
different types of Quaternary paleoecological evidence and stages in a paleoecological
study are summarized. Two major approaches to the interpretation of paleoecological
data are discussed as paleoecological reconstructions and ecological paleoecological.
Definition of Paleoenvironment
A paleoenvironment is simply an environment that has been maintained in the rock
record at some time in the past. Identifying a particular paleoenvironment from the data
available in the sediments is not so simple. Determining the geochemical parameters
associated with the environment can be very difficult largely due to diagenesis. Unique
and complex conditions during deposition of the paleoenvironment may also contribute
to the difficulty of deciphering the significance and meaning of the geochemical
signatures in the rock record. The paleoenvironment that is commonly studied from a
geochemical perspective includes a wide variety of marine and freshwater systems. Of
particular interest, marine systems are filled with basins, lagoons, carbonate shelves,
banks and reefs, and deltas. In freshwater systems, paleolacustrine deposits provide a
wide range of geochemical studies.
2.0 METHODOLOGY FOR PALEOECOLOGY AND
PALEOENVIRONMENT
Paloecology Method
Paleoecology aims to provide the perfect model of the living environment of previously
existing species discovered as fossils today. Reconstructing past environments requires
the consumption of archives, such as sediment sequences, proxies such as micro or
megafossils, and other sediment characteristics that provide evidence of the biota and
physical environment, and chronology, such as obtaining absolute or relative dating of
events in the archive. This type of reconstruction takes into account complicated
relationships between environmental elements including temperature, food supply, and
sunlight. The fossilization or diagenesis of the encircling strata sometimes loses or
distorts much of this information, making interpretation challenging. Then, Imbrie and
Kipp (1971) proposed the factor analytic transfer function, a statistical tool for
analyzing fossil assemblages that combines factor analysis and linear regression of data
on current ecological requirements of organisms, which was published in the 1970s.
This is a major step forward for paleoecological surveys from a combined qualitative
description based on the numerical count of taxa to statistical data sets with
accompanying errors and confidence levels. When it comes to integrating
paleoecologic findings into decision-making, the capacity to assess confidence in
interpretations is crucial. Furthermore, advances in stable isotope biogeochemistry and
chronologic techniques enabled more precise comparison and interpretation of the
physical and biological components of ecosystems preserved in geological archives.
Refinement of the use of transfer functions and analog datasets allowed for more precise
and statistically defensible estimations of historical climate conditions. These
advancements allowed paleoecology to widen its reach and begin to address research
concerns directly relevant to present resource management issues.
Method for Paleoenvironment
Human settlement and subsistence activities are based on interaction with the natural
world. With the reconstruction of the broader environmental context, archaeologists
can identify the main external catalysts of culture change. Modern paleo environmental
reconstruction methods have used techniques developed over the last century.
Archaeologists also need to explain the sedimentology of surface deposits to understand
the evolution of landforms. Furthermore, soils formed in stable and weathered
sedimentary deposits are an indicator of climate criticality in the past. Soils were also
first described in an excavation test unit using a macro-scale classification scheme.
However, growing microscopic techniques such as soil micromorphology in thin
sections and DNA sequences of endemic microbiota are often also used. Various types
of plant and animal communities also provide details about the environment that are
currently critical as they are often dependent on precipitation and temperature. In
general, smaller organisms are more limited in their habitat. Therefore, the remnants of
flowers and microfauna often provide the highest level of accuracy in environmental re
-conservation. Finally, nitrogen and oxygen can be tested from a wide variety of organic
materials. Thus, it can provide precise information on precipitation and biotic
communities which can be used for understanding the paleoenvironment.
3.0 CASE STUDY RELATED WITH PALEOECOLOGY AND
PALEOENVIRONMENT
Case Study from North Wadi Qena, Egypt’s Eastern Desert in the Context of
Paleoecology, Cenomanian/ Turonian Mass Extinction of Macroinvertebrates
The paleoenvironment of the North Wadi Qena area is very much important in assessing
the effects on the Late Cretaceous biota. A paleoenvironment interpretation like this
would include biotic evidence from invertebrate fossils as well as geologic or
sedimentary features like paleosols and sequence stratigraphy interpretations. Several
scientists have shown that characteristics of modern macrofaunas are strongly
associated with environmental variables, implying that invertebrate fossils might be
valuable as paleoenvironment indicators. Major extinctions are cyclical and may be
caused by similar, if not identical, mechanisms raised the exciting idea that mass
extinctions may be comprehended easily.
However, the studies of numerous Phanerozoic mass extinctions (e.g., Kauffman 1988)
have revealed that comparisons are not as straightforward as expected. These
investigations have revealed considerable disparities in the biotic, lithologic, and
geochemical fabrics of many of the mass extinctions.
Despite these differences, the broad pattern of repopulation appears to be comparable
between biotic crises, and certain events have a very correlative biotic response from a
broad range of viewpoints. This investigation aims to establish limits on environmental
changes that impact macroinvertebrates’ biota. Harries (1993, 1999), Harries and
Kauffman (1990), Harries and Crispin (1999), Kauffman (1988, 1995) and Kauffman
and Harries (1996) conducted substantial research on the Cenomanian/Turonian mass
extinction. To uncover faunal variations between Cenomanian/Turonian assemblages
and recreate how these assemblages are impacted by platform flooding and crises,
detailed analyses of macroinvertebrate fossil groups are needed. Several benthic
macrofossil groups are functional markers of environmental changes, such as
fluctuations in water depth, oxygen content, nutrient availability, or water energy, and
there are kinds of research on these groups as ecological proxies have been conducted.
The emphasis is on the questions of why many bigger benthic animals vanished during
the late Cenomanian periods and did not reappear on Turonian. Furthermore, oyster
bivalve assemblages are environmental proxies, do their presence and distribution
imply changes in water depth temperature and nutrient supply?
Paleoecology and ecosystem restoration: case study from Chesapeake Bay
Another case study that we can relate to is paleoecology and ecosystem restoration from
the Chesapeake Bay. Generally, this case study tells us about the paleoecological and
paleoclimatic reconstructions which are related to recovery planning. These happen in
the eastern US, the Chesapeake Bay, the largest estuary in the nation.
The first one is environmental degradation and restoration that occur in the Chesapeake
Bay. There are vast agriculture, urbanization, and a large number of populations in the
Chesapeake Bay. Unfortunately, all of these entities affect the water quality in rivers,
tributaries, and the Bay. Near the watershed was lived by the Native American
community. Usually, they consume the food acquired through foraging, hunting, and
maize farming (Smith 1989). These lifestyles consist an effect on land cover compared
to the changes made by European colonists. For instance, the forests there are being
cleared for 80%. And, this clearance caused erosion and downstream sedimentation.
Thus, the water clarity in the Bay is reduced. As soon as several farming lands emerged
reforested, the fertilizer consumption and development worsens the water quality there
(Willard et al. 2003).
The restoration progresses to enhance the water quality values about more than $18
billion by the year 2010 (Chesapeake Bay Commission 2003). Fortunately, Chesapeake
Bay is in the top of target for restoration planning since 1983. It started when the
Chesapeake Bay Program (CBP) was established. This strategy focused on define
water-quality criteria to protect aquatic living resources.
Miocene Vertervrate and Invertebrate burrows defining compound paleosols in
the Pawnee Creek Formation, Colarado, USA
Two case studies from the Paleogene and Neogene of the North American midcontinent
are presented in detail. The case studies involve sites in northeastern Colorado, U.S.A.,
within the late Eocene-early Oligocene White River Formation (Hembree and Hasiotis
2007a,b) and the middle Miocene Pawnee Creek Formation (Hembree and Hasiotis
2008).
Both sites consist of deposits of alluvial systems dominated by localized channel
conglomerate and sandstone and abundant, widespread paleosols. Despite their general
similarities, the two units were deposited under very different climatic conditions with
distinct landscapes and ecosystems. Much of this information is recorded in the trace
fossils preserved within the paleosol. Whereas the Eocene-Oligocene transition is well
documented in the marine record (Miller et al. 1987; Miller 1992; Ivany et al.2003),
details of the transition in the continental environment are limited by the scattered
distribution of sedimentary basins and the difficulty of correlating continental and
marine strata from this interval of time. Terrestrial plant- and vertebrate-fossil
assemblages of North America suggest the development of lower mean annual
temperature and precipitation in the late Eocene and early Oligocene (Hutchin-son 1992;
Leopold et al. 1992; Retallack 1992; Stucky 1992; Wolfe 1992; Sullivan and Holman
1996; Retallack et al.2004). Other than that, four Middle-Upper Jurassic sections from
central Saudi Arabia have been investigated to evaluate microfacies types and macroinvertebrate paleo communities and to interpret their paleoecology and
paleoenvironments. The studied Jurassic successions are part of the Middle-Upper
Callovian Tuwaiq Mountain Limestone and the Middle-Upper Oxfordian Hanifa
Formation.
4.0 USES OF PALEOECOLOGY AND PALEOENVIRONMENT
A role for paleoecology in landscape management
There is a role for paleoecology and other forms of long-term science in restoring
productive also biodiverse landscapes. In many areas of Europe, rural land
abandonment caused the degradation of semi-natural woodlands, meadows, and
heathlands due to the discontinuation of customary practices (Weissteiner et al. 2011).
Many species of high conservation value are specifically sociated with these cultural
landscapes and necessitate continuous and active management. In Europe, 55 of the 231
listed habitat types of European interest depend on, or benefit from, continued
customary practices (EEA 2011).
Paleoecological and historical studies have consistently shown a decrease in
biodiversity associated with the loss of customary land-management practices, and
higher biodiversity associated with low-intensity land uses, which generate mosaics of
wooded and grassy habitats. For example, Swedish semi-natural wood pastures and
forest meadows are important examples of relict cultural landscapes in Europe.
Paleoecological research showed a decrease in the diversity of forest taxa within the
last centuries that comes from the reduction in grazing and mowing practices.
Paleoecological knowledge is a key in the management of these landscapes (Bradshaw
and Lindbladh 2005). Similarly, remnants - a function of old grazing practices, such as
oak meadows (oak savannas) - are now threatened through the lack of grazing and
management (Fig. 1). Dahlström et al. (2008) show that the highest species richness in
plants in central Sweden is found in what today is semi-natural grassland subjected to
a long continuity of grazing. It is estimated that since 1870, 99.7% of the semi-natural
hay meadows have been lost, the few remaining semi-natural hay meadows are now
managed mainly for conservation purposes. In this case, long-term data may provide
knowledge on management practices that have now been lost.
Historical analyses show that meadows and chestnut orchards are being replaced by
forest expansion, with an overall loss in landscape heterogeneity, biodiversity, and
ecosystem services. Pastoral customary practices often combine grazing with fire
management to maintain wood pastures, but since the 18th century, many state
authorities have actively used fire both in agriculture and forestry. Shakesby et al. (2011)
showed an increase in wildfire and erosion following rural land abandonment in the
Mediterranean region, associated with increased shrub cover and afforestation with
flammable species. Paleoecological studies in the Pyrenees have shown that these
pastoral landscapes have been systematically managed by fire over millennia (Mazier
et al. 2006) and similar results have been shown for the Iberian Peninsula (Gil-Romera
et al. 2010). In Scandinavia, the ecological role of fire in both semi-natural and oldgrowth forests is now being realized (Bradshaw and Hannon 2006). In the Finnish
boreal forests, dominated by the conifers Scots pine (Pinus sylvestris) and Norway
spruce (Picea abies), local slash-and-burn practices were common until the early 20th
century. The mixed forests and grazing lands within the boreal forests are now
experiencing degradation and reduction in species diversity as slash and burn practices
have been discontinued (Myllyntaus et al. 2002). In other parts of Scandinavia, the
historical importance of fires in the boreal forests is shown by the presence of fireadapted species (Bradshaw and Hannon 2006). In all cases listed above, paleoecological
knowledge is essential in managing and restoring landscapes, and for the protection and
management of rare species through sound management practices (Gillson 2015).
Uses of Paleoenvironment
Paleoenvironment shows us the environments in which the ancient organism plants and
animals lived long ago. This work is called paleoenvironmental reconstruction.
Paleoenvironmental reconstruction can be used to develop a model of a sedimentary
environment that existed in ancient prehistoric times. Sedimentary environments
encompass both the depositional environment was sedimentary rocks are laid down as
layers called strata as well as the preservation environments where ancient organisms
were fossilized. If the organisms stayed in the same environment and were not
fossilized there after their death, then you can also think about a sedimentary
environment as a sort of habitat where the organisms lived? Paleoenvironments also
play an important role in the interpretation of archaeological data. It chronicles past
changes in climate and vegetation and can be used to predict potential human
subsistence patterns. It also gives us about the date of specific geological time in ancient
history. Paleoenvironments in archaeology teach us about past cultures through
learning about artifacts, animal bones, and occasionally human bones. The knowledge
about these artifacts provides us with some insight into what life was like for people
who left no written record. Paleoenvironmental data can be useful for understanding
the environment before, during, and after site occupation, and it can reveal
environmental changes that influenced technology, social structure, human subsistence,
and settlement strategies in modern society.
5.0 CONCLUSION
Unique and complex conditions during deposition of the paleoenvironment may also
contribute to the difficulty of deciphering the significance and meaning of the
geochemical signatures in the rock record. Paleoecology method to provide the perfect
model of the living environment of previously existing species discovered as fossils
today. This type of reconstruction takes into account complicated relationships between
environmental elements including temperature, food supply, and sunlight. This is a
major step forward for paleoecological surveys from a combined qualitative description
based on the numerical count of taxa to statistical data sets with accompanying errors
and confidence levels. Furthermore, advances in stable isotope biogeochemistry and
chronologic techniques enabled more precise comparison and interpretation of the
physical and biological components of ecosystems preserved in geological archives.
Refinement of the use of transfer functions and analog datasets allowed for more precise
and statistically defensible estimations of historical climate conditions. These
advancements allowed paleoecology to widen its reach and begin to address research
concerns directly relevant to present resource management issues. Several scientists
have shown that characteristics of modern macrofaunas are strongly associated with
environmental variables, implying that invertebrate fossils might be valuable as
paleoenvironment indicators.
Other than that, four Middle-Upper Jurassic sections from central Saudi Arabia have
been investigated to evaluate microfacies types and macro-invertebrate paleo
communities and to interpret their paleoecology and paleoenvironments. In many areas
of Europe, rural land abandonment caused the degradation of semi-natural woodlands,
meadows, and heathlands due to the discontinuation of customary practices. Historical
analyses show that meadows and chestnut orchards are being replaced by forest
expansion, with an overall loss in landscape heterogeneity, biodiversity, and ecosystem
services. In the Finnish boreal forests, dominated by the conifers Scots pine and Norway
spruce, local slash-and-burn practices were common until the early 20th century.
Paleoenvironmental data can be useful for understanding the environment before,
during, and after site occupation, and it can reveal environmental changes that
influenced technology, social structure, human subsistence, and settlement strategies in
modern society.
6.0 REFERENCES
⮚
Ahmed. A. (2008a, January). Cenomanian/Turonian mass extinction of
macroinvertebrates in the context of Paleoecology; A case study from North Wadi
Qena, Eastern Desert, Egypt. Academiaedu. Retrieved November 10, 2021, from
https://www.academia.edu/3392436/Cenomanian_Turonian_mass_extinction_of_
macroinvertebrates_in_the_context_of_Paleoecology_A_case_study_from_North
_Wadi_Qena_Eastern_Desert_Egypt
 Ekblom. A. & Gillson. L. (2017). The importance of paleoecology in the
conservation and restoration of cultural landscapes. Pages Magazine, 25(2), 88–
89. https://doi.org/10.22498/pages.25.2.88
⮚
H. Stephen T. & H. Daniel I (2008). Miocene vertebrate and invertebrate burrows
defining compound paleosols in the Pawnee Creek Formation, Colorado, U.S.A.
Palaeogeography Palaeoclimatology Palaeoecology, 230(3–4), 349–365.
https://doi.org/10.1016/j.palaeo.2008.07.019
⮚
W. Debra A. & C. Thomas M. (2007). Frontiers in Ecology and the Environment.
Paleoecology and Ecosystem Restoration: Case Studies from Chesapeake Bay
and the Florida Everglades, 5(9), 491–498. https://doi.org/10.1890/070015
⮚
W. David K. (2017, July 27). Paleoenvironmental Science: Methods. African
History. Retrieved November 11, 2021, from
https://oxfordre.com/africanhistory/view/10.1093/acrefore/9780190277734.001.0
001/acrefore-9780190277734-e-211
⮚
H.J.B. Birks and T. Webb (2008). Paleoecology. Paleoecology. Retrieved
November 12, 2021, from https://www.sciencedirect.com/topics/agricultural-andbiological-sciences/paleoecology
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