Ecology Lecture 1 10/29/15 9:33 AMLecture 1:- What is ecology?

The branch of biology that deals with the relations of organisms to one another and to their physical surroundings/environment

The political movement that seeks to protect the environment, specifically from pollution

Is essential for the survival of the human specieso For arriving at practical decisions concerning the

management of natural resourcesWhy is ecology so important?

Mass culture where humans are not concerned about their impact on the environment

Air pollution is ridiculous in china Climate change is impacting every organism in the planet

Environmental science is not environmentalism Environmental science

o The pursuit of knowledge about the natural worldo Objective

Environmentalismo Activismo Dedicated to protecting the natural world

Nature of ecology “study of the household” Body of knowledge concerning the economy of nature

Ecosystem: can be a tiny little puddle or a massive oceanWhat are the components of an organism’s environment?

All organisms acquire nutrients form the surround environmento Make a living

Use these resources to protect and reproduceLevels of organization

Individual Population Community Ecosystem Biome Biosphere

Birth and Death The effect of birth and death can be studied at multiple levels

1) individual – birth and death are discrete events and happen only once2) population – birth and death are continuous, measured as rates or probabilities3) community – focus shifts to relative abundance of species within the community

ecology has its root in plant geography and natural history from the 1800s

plant geographers noticed similar climates had similar vegetation Plant association: correlation of vegetation with environmental

characteristicso Realization that the form and function of their physical

environment CONVERGENT EVOLUTION

Evolutionary ecology: focuses on studying the role of natural selection in adaptations and speciation

Physiological ecology: concerned with the responses of individual organisms to environmental conditions

Principle of Tolerance limits As the climate is changing, is vital to understand how species adapt

to a changing climate Landscape ecology: explores spatial processes that link adjacent

communities and ecosystems; uses remote sensing data; geographical information system

o Maps with layer upon layer of information and understand aspects of the environment in a visual way

Conservation ecology: applies principles from different fields, including ecology, economics, and sociology to preserve biodiversity, protecting the environment and its habitants

o Humans: habitat loss (fragmentation) and shipping Restoration ecology: uses principles of ecosystem function to

restore and manage disturbed areas – environmental engineeringo Protect the soil!!!!

Systems ecologyEcosystem – emphasis shifts from species to the flows of energy and nutrients

Energy and nutrients are converted into biomass and then are broken down and decomposed

Earth’s Carbon Cycle:o Humans disturbance – at the fossil fuels

Moving carbon sinks into the atmosphereHydrocarbons – burn hydrocarbons and release carbon into the atmosphere

Get CO2, Water, and EnergyNitrogen Cycle – issues: nitrogen as the building blocks of protein, its limiting element

People have figured out to take nitrogen-carrying bacteria and take that and make it available to plants and organisms

Haber Process – reaction between nitrogen and hydrogeno N2 + 3H2 2NH3o Facilitated invention of synthetic fertilizers incredible yield

of foodo However, fertilizers leads to leaching and get into the water

Phosphorous Cycle Usually obtained either through leaching through rainstorms and

water Or from decomposers (fungi) All the reserves of phosphorous is in morocco or the saharas We may have reached peak phosphorous; demand keeps rising but

the supplies is diminishingEcologists investigate nature using scientific method

1. Make observation 2. Form a question based on that observation

o ex. In north American prairie grass lands have different levels of productivity – biomass

3. Hypothesis: an educated guess, cause and effect statement

o ex. Nitrogen could be the reason why one of the ecosystem is productive and the other isn’t

4. test the hypothesis involves testing the predictions to see if it holds true

o field study: can eliminated temperature, soil quality, etc and only add more nitrogen to some field plots and not in others

o be careful not to add too much nutrient because it becomes toxic and you can kill your plants

ammonium toxicity these data do not prove that nitrogen is the only factor influencing

plant productivity other factors, such as soil moisture or acidity, could also be

responsible for the observed relationship Tried to grow the grasses in a greenhouse or more control; but

greenhouse conditions are different than those in a field, so response may be different than the real environment

Uncertainty is an inherent feature of scienceThe scientific method is a continuous process of testing and correcting explanations to refine our understanding of the world around us

As a result, only part of the picture is seenWe are limited to inspecting only a part of nature because to understand we must simplifyToday, many ecologists are studying the dominant role that humans are playing in earth’s ecosystemsExponential Growth = resources are unlimited and a population experiences exponential growth when the size increases at an ever increasing rate

Go into a singularity infinity Resources become limited and graph turns sigmoidal Invasive species in San Francisco is also increasing J curve

o human population is a J curve; making more habitat and more extinction

10/29/15 9:33 AM

10/29/15 9:33 AM