BIO 307 — Field Course I: Lecture Note

About this lecture note

This is the complete lecture note for BIO 307 Field Course I. You can read it online below, open it in the full viewer, or download the PDF for offline study. It pairs with the course's video lectures, so you can read and watch together.

Preview: opening of the note

BIO la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS

BIO la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Course code: BIO 307 Course title: Field Course I Course credit load: 1 Unit Series 1: Field Sampling Techniques • Part 1.1: Principles and Planning of Field Sampling o Sub Part 1.1.1: Purpose and importance of field sampling o Sub Part 1.1.2: Study design and sampling strategy o Sub Part 1.1.3: Field safety and ethical conduct • Part 1.2: Quantitative Sampling Methods o Sub Part 1.2.1: Quadrat and transect methods o Sub Part 1.2.2: Mark-recapture and point count methods o Sub Part 1.2.3: Pitfall traps and sweep nets • Part 1.3: Recording, Data Management, and Equipment o Sub Part 1.3.1: Field recording and data sheets o Sub Part 1.3.2: Equipment for field sampling o Sub Part 1.3.3: Handling and storing samples in the field Introduction Field biology is the practice of studying living organisms in their natural environment rather than in the laboratory, and the quality of any field study depends entirely on how carefully samples are collected, recorded, and managed. Sound sampling techniques allow biologists to make

BIO la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS reliable estimates of species composition, abundance, and distribution from a limited number of observations, and to draw valid conclusions that extend beyond the specific locations and times sampled. This Series introduces the principles of field sampling as applied within local habitats up to 20 km from the university, covering the purpose and planning of field studies, the major quantitative sampling methods used in biological fieldwork, and the equipment, data recording, and sample-handling procedures that ensure data quality from the field to the laboratory. These skills underpin all the habitat-specific and collection work covered in the remaining Series of this course. Series Learning Outcomes Upon completing this Series, you should be able to: • SLO 1.1 explain the purpose of field sampling, describe study design principles, and apply field safety and ethical guidelines, • SLO 1.2 describe and apply quadrat, transect, mark-recapture, point count, pitfall trap, and sweep net sampling methods, and • SLO 1.3 demonstrate correct field data recording, equipment use, and sample handling procedures. 1.1 Principles and Planning of Field Sampling 1.1.1 Purpose and importance of field sampling Field sampling allows biologists to characterise the organisms present in a habitat (species composition), estimate how many individuals of each species occur (abundance), map where they occur (distribution), and monitor changes in these parameters over time; because it is impossible to count or record every individual in most natural habitats, sampling provides a practical means of obtaining representative data from which inferences about the whole population or community can be drawn, provided the sampling is well-designed and unbiased.

BIO la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Field data collected through systematic sampling have applications across ecology, conservation, environmental impact assessment, pest management, and basic biological research; in the local context, field sampling within habitats near the university provides the raw data for understanding the diversity and structure of Nigerian terrestrial, aquatic, and forest-edge communities, and gives students direct practical experience of the organisms and environments studied in lecture courses. Fill in the blank: Field sampling provides a practical means of obtaining ________ data from which inferences about the whole population or community can be drawn, provided the sampling is well-designed and unbiased. 1.1.2 Study design and sampling strategy A sound study design specifies the question to be answered, the variables to be measured, the spatial scale and location of sampling, the number of sampling units, and the method of allocating sampling units across the study area; the three main sampling strategies are random sampling (sampling units placed at randomly chosen locations, minimising bias but potentially missing important habitat patches), systematic sampling (sampling units placed at regular intervals across the study area, ensuring even coverage), and stratified sampling (the study area divided into strata reflecting known habitat differences, with sampling units allocated proportionally within each stratum to ensure representative coverage of all habitat types). The number of sampling units (replicates) required depends on the degree of natural variability in the system and the precision required from the study; pilot sampling (a small preliminary survey to estimate variability) is useful for determining the appropriate sample size before the main study; for most field biology assessments, a minimum of five to ten replicate sampling units per habitat or treatment is a practical guideline, though more may be needed in highly variable habitats. Fill in the blank: ________ sampling divides the study area into strata reflecting habitat differences and allocates sampling units within each stratum, ensuring representative coverage of all habitat types.

BIO la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 1.1.3 Field safety and ethical conduct Field safety requires that all participants are briefed on hazards specific to the study site before the visit (including dangerous animals such as snakes and stinging insects, unstable terrain, deep water, and traffic near roadsides), that appropriate personal protective equipment (sturdy footwear, long trousers, sun protection, and in some habitats, anti-malaria precautions) is worn, and that participants work in groups of at least two, never alone; a field first-aid kit should always be carried, and the location and contact details of the nearest medical facility known before departure. Ethical conduct in field biology requires that collecting and sampling activities cause the minimum necessary disturbance to the habitats and organisms studied; protected species should not be collected without the appropriate permits; collecting permits are required for many animal groups even in non-protected areas; invertebrates and small vertebrates captured for identification should be released after recording unless voucher specimens are specifically required; field sites on private land or protected areas require written permission from landowners or site managers before entry. Fill in the blank: Field ethical conduct requires that sampling causes the ________ necessary disturbance to habitats and organisms, and that protected species are not collected without the appropriate permits.

BIO la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Figure 1.1: Field sampling principles and safety Pilot questions 1.1 1. State three types of information that field sampling can provide about organisms in a habitat. 2. Distinguish between random, systematic, and stratified sampling strategies. 3. Explain why pilot sampling is useful before a main field study. 4. Name three field safety precautions that should be taken before a field visit. 5. Explain what is meant by ethical conduct in field biology. 1.2 Quantitative Sampling Methods 1.2.1 Quadrat and transect methods A quadrat is a defined area (typically a square of fixed dimensions such as 1 m x 1 m for herbaceous vegetation or 10 m x 10 m for trees) within which all organisms of the target group are counted, measured, or identified; quadrats may be placed randomly, systematically, or

BIO la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS stratified across the study area; plant percentage cover, species frequency (the proportion of quadrats in which a species occurs), and species density (number of individuals per unit area) are the most commonly recorded quadrat variables in vegetation surveys. A transect is a line along which observations or measurements are made at regular intervals, or within defined plots placed along the line; belt transects (a strip of defined width along the transect line, within which all target organisms are recorded) and line transects (along which point observations are made at regular intervals) are the most common types; transects are particularly useful for recording changes in species composition across environmental gradients such as from water edge to dry land, or from forest to grassland. Fill in the blank: A ________ transect is a strip of defined width along a line within which all target organisms are recorded, useful for mapping changes across environmental gradients. 1.2.2 Mark-recapture and point count methods Mark-recapture is a method for estimating the size of animal populations that are difficult to count directly; a sample of individuals is captured, individually marked (with paint, tags, rings, or fin-clips depending on the animal), and released; after sufficient time for the marked individuals to mix randomly with the population, a second sample is captured; the proportion of marked individuals in the second sample relative to the total sample is used to estimate total population size using the Lincoln-Petersen formula: N = (M x C) / R, where N is population size, M is the number marked and released, C is the total second sample, and R is the number recaptured. Point count (or point census) methods are widely used for sampling birds and, in some contexts, other conspicuous animals or plants; an observer stands at a fixed point for a defined period (typically 5 to 10 minutes) and records all individuals seen or heard within a defined radius or without a distance limit; multiple point count stations distributed across the study area provide an index of relative abundance

This is the opening of the note. Read the full note or download the PDF to continue.