Introduction to Ecology

Introduction to Ecology

• Ecology comes from the Greek words "oikos," meaning house, and "logos," meaning study.
• Ecologists supervise forest parks.
• They assess the impacts of construction or damages on the environment.
• Ecologists can work for companies extracting petroleum
• They can work in ecotourism
• Professor/researcher are also career paths for ecologists.

Relations with Other Areas

• Economics is derived from the Greek phrase "management of the house."
• Zoology allows for understanding insects and other animals related to the environment.
• Landscaping involves physical aspects that can compromise visual features like pollution.
• Health involves the relationship between population health and environmental balance.

Basic Concepts

• Injury is any harmful action or damage resulting from an organism's activities, such as feeding, or trauma produced by an external force.
• Lesion indicates the action of a pathogen.
• Damage is any loss resulting from an injury or lesion, and it can be ecological, social, or political.
• Loss is when there is a drop in production or simply a loss of money.

History of Ecology

• Primitive humans needed ecological knowledge for survival, requiring they understand natural forces as well as the plants and animals around them.
• Hippocrates, Aristotle, and other Greek philosophers included ecological themes in their works.
• The Middle Ages was characterized by an Aristotelian vision of nature, believing nature was always in perfect balance.

Important Scientists

• Gaunt pioneered demography with studies of mortality, sex ratios, and birth rates.
• Leeuwenhoeck (1632) highlighted the importance of food chains and population regulation.
• Richard Bradley focused on biological productivity.
• Buffon (1756) established the basic principle of ecological regulation of populations.
• Malthus (1798) posited that populations could grow exponentially while the resources to sustain them increased arithmetically.
• Darwin (1859) and Malthus shifted the Aristotelian view, recognizing species extinction, competition due to population pressure, and the evidence of natural selection.
• Ernest Haeckel in Germany, 1866, first proposed the term ecology, defining it as "the study of the house."
• Ecology studies the complex interrelationships described by Darwin as conditions in the struggle for existence and comprehends the relationship of organisms with their environment.

Modern definitions of ecology

• Elton (1927) called it scientific natural history.
• Krebs (1972) defined it as the scientific study of interactions determining the distribution and abundance of organisms, noting the importance of biotic interactions like predation in structuring communities.
• Ricklefs (1973) saw it is as the study of the natural environment, focusing on interrelations between organisms and their surroundings.

Advances in the 19th and 20th Centuries

• Animal Ecology x Plant Ecology = General Ecology
• Möbius (1877) introduced biocenosis when studying a community of organisms in an oyster bed.
• Forbes (1887), Forel (1892), and Thienemann (1926) pioneered aquatic ecology (limnology).
• Warming (1895) did phytosociological studies in the cerrado of MG.
• Cowles (1899) described ecological succession on the dunes of Lake Michigan.
• Clements (1916) created the concept of community evolution.
• Tansley (1935) proposed the ecosystem as the basic unit of ecological study.
• Yellowstone was established in 1872 as the world’s first national park.

Advances in Ecology

• In the 1960s, NGOs emerged notably in 1961.
• The 1970s saw the rise of political and state actors in ecology.
• The first Conference on the Human Environment happened in Sweden in 1972.
• The first Conference on Population and Development happened in Romania in 1974.
• The 1980s saw the rise of eco-development and sustainable development.
• The Second Conference on Population and Development happened in Mexico 1984, establishing that the responsibility for birth control lies with governments.
• Sustainable development emerged as a concept upon the publication of "Our Common Future" (the Brundtland Report) in 1987, prepared by the World Commission on Environment and Development.

Sustainable Development

• Sustainable development involves meeting the needs and aspirations of the present without compromising the ability to meet ones in the future.

Challenges in Ecology

• Ecology deals with millions of different species, a huge amount of individuals, and all of their interactions in an evolving world.
• Its main goal is to explain and understand the world around us.
• Immediate explanation, distribution and abundance of a species can be explained the environment, food source, predators, etc.
• Final explication relies on the ancestral conditions.
• It is necessary to describe things before understanding them.
• Ecologists try to predict future with organisms under particular circumstances and try to control or explore them.

Autoecology vs. Sinecologia

• Ecology was divided by Schroter in 1896 in two big segments
• Autoecology studies the influence of external factors on an individual animal or plant species and its relation with the environment.
• Synecology is the study of groups of organisms associated e.g. study of communites, including animals and plants.

Ecosystems

• Another important aspect for understanding the science of Ecology is levels of organization - Genes, cells, tissues, organs, systems, species, populations, communities, ecosystems, and the biosphere.

Ecosystem Definitions

• Species - Two or more organisms considered the same species when they can reproduce, generating fertile descendants.
• Populations - Groups of organisms from the same species.
• Communities - Includes all populations that occupy a certain area.
• Ecosystem - A community and the non-living environment.
• Habitat - A location where a species lives, for example, the maned wolf lives in the cerrados.
• Ecological Niche - The unique way a species relates to the distribution and obtention of energy in its habitat.

Biosphere vs. Ecosphere

• Biosphere/ecosphere refers to all ecosystems combined, including aquatic, terrestrial, and aerial ones. It is the part of the planet with life where life can have an affect.
• Ecology is divided into the ecology of species, populations, communities, and ecosystems.

Population Density

• Population density numbers of individual per unit or volume

How to Measure Population

Methods of Amplitude

• square method
• Catch and Recapture - Mark does not disappear/mortality rate
• Relative Density - study of abundance ratio
  • Capture Trap
  • Counting Fecal Balls
  • Bird vocalization frequency
  • Questionnaires and surveys about vertebrates
  • Amount of consumed baits

Population Attributes

• Natalidade - Term to describe the production of new individuals per time
• Fertility - Quantity of successful births/varies depending on population
• Mortality - estimated on the field through tagging and finding, through a life table
• Migration - Quantity of individuals that enter and exit and environment.

Life Tables

• Survival Curves
  • Type 1
  • Type 2
  • Type 3
• Population Fluctuation
  • Term used to define a lifecycle of an organism/variations in the cycle

Synthesis of Factors that Regulate Population

• Predation
• Sickness
• Competition
• Increased genetic inviability
• Parasitism
• Genetic Issues
• Alimentation
• Change in Reproductive Biology
• Space
• Climate

Trophic Ecology

• This ecology term represents the existing connection between a group of organisms in an ecosystem and is defined by the predator and prey relationship.
• Through the alimentary or tonic chain is possible to transfer energy between living beings

Alimentary Chain and Web

• Alimentary chain
  • Grazing Trophic Routes
  • Matter is live vegetation herbivore and shepherds
  • Detritus - Shepherds don't consume vegetable/decomposed matter -Producers - Organisms that produce through photo or chemical synthesis. Accumulate energy through bio chemical processes that use water, carbon, and light.
  • Consumers - Primaries are that eat produces.
  • Secondaries - Animals that eat herbivores/carnivores
  • Terciaries - Big predators that capture prey at the top of the chain. They are characterised by big sizes and minimal quantities.
  • Onivores - eat everything
  • Decomposers - Responsible for decomposing matter, transforming it into available minerals, and represented through bacteria and fungus completing the cycle.

Trophic Levels

• All individuals that aliment the same elements are on the same level.
• Producers - stand at level 1
• Primare consumers eat other producers and occupy second level.
• Secondary consumers - eat other primary consumers.
• Decomposers - occupy the last level transferring energy and composing producers and consumers.

Aquatics alimentary chain example

• Producers
  • Composed by plants at the side of the lake and micro plants/algaes responsible for oxidation in the environment. It is called phytoplankton
• Consumers 1
  • Small floating animals
  • Snails and Herbivore Fishes.

Consumindores Nível 2

• Feed of previous level; Fishes, etc
• Consumers 3
  • Aquatics bords that feed over second level consumers
• Decomposers
  • Do not pertain to Fauna and Flora, and are formed of fungus and bacteria

2: Alimentary Webs

• However, the Alimentay cannot show complex trophic relatiosnhips. Webs are real situations found in an area where multiple interlocked chains simultaneously occur.
• Species can be a key element

Important of alimement Chains

• How species behave is key to understand the environment.
• Utilise biological control instead of the use of artificial elements that can harm.
• Fish that combat esquistossomose and Aedes aegupti, plus bacterias that can serve as plagues/bugs.

3: Ecological Pyramids

• Considers the Density number by area in many different trophic levels.
• Biomass P. Consider biomass
• Energetic P. Indicate energetic magnitude of interactions inside the community.