Wednesday, 21 March 2018
Friday, 9 March 2018
The Mosses with the Mostest
Not Bog Standard....
Peat bogs take hundreds or even thousands of years to form being made up of vegetation typical of acid bog environments, such as Sphagnum mosses, that have not fully decayed due to the acidic conditions (some bogs are entirely rain-fed so nutrient and oxygen poor, rather than gaining nutrients from ground water sources).Sphagnum moss bogs as carbon stores and methane recyclers are vital to our atmosphere; they help to clean water running through the mosses and also help to prevent flooding in lowland areas.
This habitat is vulnerable to human interference and can either dry out (through water diversion or tree planting) or become enriched which changes the plant species and subsequently the invertebrates that live there. This is why the conservation of acid bog habitats is so important.
Leaf Morphology
Shape Shifters
Extract from our online course Botany and its role in the ecosystemSome plants exhibit morphological traits related to the environmental conditions in which they live.
The most important physical factor which has the most impact on
leaf shape is light. Leaves that trail along the ground surface or are shaded by other
vegetation get less light and tend to be larger.
Using
an Ivy leaf as an example
Ivy (Hedera helix) exhibits
morphological traits dependent on its growth stage. The mature leaves of Ivy
exhibit the flowers and fruits whereas the broader, lobed leaves are the
immature leaves. The immature leaves tend to trail on the ground in the shade
whilst the mature leaves climb to the light. The difference in shape and
diameter between immature and mature leaf is thought to be in response to the need to
photosynthesise, with the larger size of the immature leaf providing a greater
surface area to gain maximum energy from sunlight. The morphological difference may also be connected
to the way that the immature plant takes up and transports nutrients via xylem
and phloem (i.e. the need to develop shoots and grow quickly in order to reach
light). In regards to evaporation, the larger immature leaf will not transpire
as much as the mature leaf so can be bigger without risk of losing water.
Thursday, 8 March 2018
Getting Closer: Using a hand lens
Eye Spy....
Sometimes the only way to identify a plant is by looking to see how rounded or angled (square) the stem is; whether it is smooth or furrowed and whether hairs are present or absent. To narrow down identification even further you may also need to determine the shape and type of hairs that are present.To identify some plants a microscope is needed, but for the most part a 10x magnification hand lens is sufficient for identifying most species out in the field. However, for closer inspection, you may want to use a 20x or 30x magnification hand lens.
To use a hand lens correctly, hold it to your eye and bring the plant up to the hand lens. Allow time to focus – you may need to draw the plant closer towards the hand lens or further back to get it into focus.
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