Download Freshwater Ecology - Field Studies Council

SAMPLING TECHNIQUES AT RHYD Y CREUAU
Site: Coed Hafod - A 25 Hectare semi natural ancient oak woodland
situated on the eastern side of the Conwy Valley.
INVESTIGATION 1 - THE ASSOCIATION OF MOSS SPECIES IN AN ANCIENT WOODLAND
Introduction
Mosses and liverworts (Bryophytes) are non-vascular plants. This means that they do not contain
vascular tissue to conduct water and other nutrients through them. All bryophytes can absorb water
through the entire body surface and so have very thin cell walls and cuticles. In place of roots, most
bryophytes have thin, hairy tubes called rhizoids that provide anchorage and sometimes nutrient
uptake from the substrate. They also produce spores instead of seeds and are generally found in moist
shady environments.
Aims


To describe the moss communities present in an ancient woodland.
To relate these communities to abiotic and biotic gradients that may be present.
Hypothesis (Describe the distribution in moss you are expecting to find)
………………………………………………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………………………………………………
Null Hypothesis..............................................................................................................................................
.......................................................................................................................................................................
INVESTIGATION 2 - LICHEN COMMUNITIES ON OAK AND BIRCH TREES
Introduction
Lichens are a mutualistic symbiosis between fungi (the mycobiont) and an algae or a photosynthesising
bacteria (the photobiont). The algae or bacteria contributes carbohydrates from photosynthesis and the
fungus provides the algae with protection from strong sunlight and desiccation. They are generally
‘pioneer species’ needing plenty of light and are often found encrusting rocks or walls or growing on the
trunks or branches of trees, especially in areas of high rainfall and low pollution.
Aims


To compare the lichen flora of birch (Betula spp.) and sessile oak (Quercus petraea) trees
To discuss possible reasons for any differences found
Biotic Hypotheses

There will be a significantly greater % .................... of fruticose lichen on ……………………………
Null hypothesis: ..............................................................................................................................

There will be a significantly greater % .................... of foliose lichen on
….…………………………
Null hypothesis: ..............................................................................................................................

There will be a significantly greater % .................... of crustose lichen on .……………………………
Null hypothesis: ..............................................................................................................................

There will be a significantly greater % ....................
of moss on
…….……………………
Null hypothesis: ..............................................................................................................................
Abiotic Hypothesis

There will be a higher level of ……………………………
on
……………………………
Null hypothesis: ...............................................................................................................................
OBJECTIVES:
During the day these projects will enable us to:
Tick when achieved

Discuss and use a variety of techniques for the sampling of ecological material

Consider appropriate methods of planning and implementing ecological studies

Introduce ideas about how to summarise data graphically and statistically

Cover some of the basic ecological terminology and concepts needed to
understand and interpret the results of ecological studies
Your objective:
……………………………………………………………………………………………………………………………….
……………………………………………………………………………………………………………………………….
CONCEPTS WE’LL BE COVERING:
Rank between 1 (unknown) and 5 (very confident)
i - Sampling Techniques

Quadrats

Transects

Random sampling

Replication

Describing vegetation (% cover, % frequency, density, biomass etc)

Recording data
ii - Investigative Skills

Observation

Identifying a problem

Variables (key and control variables)

Hypotheses

Designing sampling methods
iii - Analytical Skills

Graphical representation of data

Methods of summarising data (mean, median and mode)

Statistics
iv - Ecological

Biotic factors

Abiotic factors

Population, community, ecosystem

Niche

Intra and interspecific competition

Population dynamics – carrying capacity, density dependent /
independent factors etc
Before
After
Effects of Climate Change
Temperate rainforests such as Coed Hafod require year round rainfall of at least 1500mm annually and
a lack of extremes of temperature. This creates some of the most species rich environments on the
planet for damp loving plants such as mosses and ferns as well as for lichens. (Coed Hafod alone has
over 140 recorded species of moss). Most climate change patterns predict damper winters and hotter
and drier summers, this will have a devastating effect on these organisms which thrive only as a result
of year round moisture and high humidity levels.