IBDP Biology Chapter 14 Notes

ecology and conservation


These notes have specially been curated by expert teachers to simplify and enlighten concepts given in IB Biology HL. The notes are comprehensive in nature and are sufficient to study the chapter in depth and one need not look for other resources beyond the notes provided on our website which can be accessed for free. The notes for Cell Biology IBDP HL are available on our official website and can be downloaded for free. You are one click away from obtaining all that you need to score well in IB Biology HL.

The material made available on Tychr’s website is available for all IBDP subjects and is specially curated after an extensive amount of effort to ensure that the notes are in consonance with the IB curriculum and are an amalgamation from various textbooks prescribed by the IBO.Students often face a challenge understanding concepts, especially concepts that are new and tricky. These IB Biology Notes will help the student cover the chapter of Cell Biology entirely while explaining each and every concept in a detailed and easy way.

This unit revolves around the ecosystem, its population and conservation. We start by defining species, population and community. We also discuss Shelford’s Law of tolerance which determines the distribution of species according to their tolerance. Then we examine the disproportionate importance of keystone species in maintaining an ecological community and ecological niches influencing competition between species.

We also ponder the inter-species interactions (like herbivory, predation, parasitism, mutualism and commensalism. We then reexamine the pyramid of energy and how biomass and energy get lost every time they are transferred. We also learn about the FCR, i.e. the Food conversion Ratio( lower FCR= higher efficiency). Primary succession occurs when no life existed, and secondary succession occurs on land with already fertile soil. Then we learn the representation of nutrient stores (soil, biomass and litter) through Gresmehl diagrams.

Alternatively, we also learn about the impacts of humans on ecosystems through alien species which become invasive. We also dive into biomagnification because toxic substances (insecticides like DDT) accumulate at higher trophic levels. Then we deal with the impact of macroscopic and microscopic(<5mm) plastics. Conservation of biodiversity has two components, richness and evenness, and can be of two types, ex-situ or in situ. Population ecology deals with population dynamics and population growth curve. Then we end the unit with nitrogen and phosphorous cycle and the effects of eutrophication.