Grimes' Triangle

Grimes' Triangle has 3 points to it as seen in figure 1 below these are naturally referred to as "C-S-R" in many scientific reports for abbreviation.
The C stands for competitions with plants
The S stands for Stress
The R stands for ruderal (Meaning a plant growing on a space where there is already crowded plants)



 Grime's C-S-R triangle theory has been discussed in plant ecology for two decades, but it has rarely been tested, and not often dispassionately evaluated. We consider the theory from a community viewpoint, and attempt to develop and test predictions for plant communities. C-S-R assumes that in high-disturbance (ruderal, R) patches or habitats, competition will be absent, or low in intensity. Testing this is problematic because of the difficulty of defining the intensity of competition, and we could find no rigorous evidence to support or refute the prediction


Wilson, J. and Lee, W. (2000). C-S-R triangle theory: community-level predictions, tests, evaluation of criticisms, and relation to other theories. Oikos, 91(1), pp.77-96.

Co-Evolution

What is Co- Evolution?

In biology, Co-Evolution occurs when changes in at 2 or more species genetics compositions reciprocally affect each others evolution.
I.e. the Bird and the Flowers, The Spider crab and the Alga, The bacteria and the Humans.

Types of Animal Interactions

• Phoresis
• Comensalism
• Mutualism
• Parasitism
• Predator Vs Prey
• Competition

 

PHORESIS.

In biology, the term phoresis is an inter-species biological interaction in ecology and refers to a form of symbiosis where the symbiont, termed the phoront, is mechanically transported by its host. Neither organism is physiologically dependent on the other.
Example; mosquitos take small amount of blood from humans neither is helped nor harmed but travelled with.

figure 1; Mosquito showing its taking blood

COMENSALISM

Comensalism is a relationship between two organisms where one receives a benefit or benefits from the other and the other is not affected by it.
I.e. Pilot Fish live round shark to eat the parasites that came of them, Some Orchards live on trees not harming them etc

Figure 2; Pilot Fish Live round sharks to eat the parasites around them
not affecting the shark

MUTUALISM

Symbiotic interaction between different species that is mutually beneficial
I.e. The Bee and the Flower, Monkey and Fruit.

Figure 3. Mutualism as there is a benefit for both the pollen gets transported across
the ecosystem and the insect gets it usage of pollen to produce what it needs to

PARASITISM

In biology/ecology, parasitism is a non-mutual symbiotic relationship between species, where one species, the parasite, benefits at the expense of the other, the host. Traditionally parasite (in biological usage) referred primarily to organisms visible to the naked eye, or macroparasites (such as helminths).
I.e. Bed bug, ring worm, Tape worm.

Figure 4. Mites on dogs are a Parasitism, the dog is not benefiting and the mite can not
been seen with the naked eye 

PREDATOR VS PREY

In an ecosystem, predation is a biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked). this is a relationship where an organism is likely to not survive.
I.e gazelle vs lion, Birds vs Butterfly, fox vs Rabbit

Figure 5. Fox Vs Rabbit

COMPETITION

Competition is an interaction between organisms or species in which the fitness of one is lowered by the presence of another. Limited supply of at least one resource (such as food, water, and territory) used by both can be a factor.
I.e, the Fight between bacteria and humans, grass and sheep.



Figure 6. All the Competition in one comic stripe

Plant-Plant Interactions

• Inhabitation
• Competition (As above)
• Facilitation

Further Reading;

Morris, J., Hartl, D., Knoll, A. and Lue, R. (n.d.). Biology.

 

 

 

 

 

R and K selection

As the name implies, r-selected species are those that place an emphasis on a high growth rate, and, typically exploit less-crowded ecological niches, and produce many offspring, each of which has a relatively low probability of surviving to adulthood.

HIGH (Reproductive Rate) = R
LOW (Reproductive Rate) = K

K species live in populations that are near or at the equilibrium conditions for long periods of time. Competitive for limited resources is very important in these environments.
I.e. Lemmas, Giraffe, elephants and bats.

R species live in populations that are highly variable. the fittest individuals in these environment have many offspring and reproduce early.  
I.e. Mosquitos and Toads.


Figure 1. A table showing r-K scale of reproductive of balancing egg outputs

Dis/Advantages of being a K species;

• reproductive rate last long time along with parental care making them a weakness to a competitive environment. (Dis)
• More care to young makes them more ability to survive in the wild as they will have learned behaviours from parents (Ad)
• The young will have be dependant on the mother which in order makes the mother a target for predators as she has herself to protect as well as her young (Dis)
• Fewer, Larger offspring. (Dis)
• Later reproductive age (Dis/Ad)
• High parental Care and protection for offspring (Dis)
• Larger Adults (Ad)
• Adapted to stable conditions of the environment (Ad)
• Population size fairly stable and usually close to carrying the capacity (Ad)

Dis/ Advantages of being a R species;

• where there is a short reproductive period there is less weakness for the a competitive environment (Ad)
• Likely that more young is produced known that at least one young will survive however they do have to learn on there own due to lack of parental care. (Dis)
• No young dependent on mother however this means lack of survival (Dis)
• Lower population growth rate (Dis)

Figure 2; Comparison chart for the R and K

 

The Coppice Cycle Modern/ Ancient

In a coppiced woodland, young tree stems are repeatedly cut down to near ground levels. In subsequent growth years, many new shoots will emerge and after a number of years of the coppiced tree or stool is ready to be harvested and the cycle will be ready to start again.

coppicing was used in medieval times however not like it is today, it was operated to produce a crop of wood of different ages. Five year old coppice would be used for sheep hurdles, hedging stakes and thatching spars. All older wood could be used for fencing material, furniture and firewood as it lasted longer then developing wood. The cutting of different areas at different times produced age structuring.

Whereas, through the 18th and 19th centuries coppiced woodlands provided industrial charcoal for smelting of iron and bark was used for the tanning of liquors.

Fig 1.Hothfield Common;
 Hardly any
trees in 1961 

Fig 2. Trees encroaching and
covered most of the bogs in 1972.

However, by the mid- twentieth century coppicing was in a rapid decline and therefore many coppicing woodland was replaced with conifers or just neglected. Today society have protection over land with Coppicing trees such as Oak and Breach for example Hothfield Common as the land was neglected over time to a point where there was no woodland and the bogs began to dry up.





Management at Hothfield Commons do use the coppice cycle however only to a point where they can maintain the woodland so it does not engulf the bogs, the wood is used for the local people for firewood much like the medieval times.

Refeances /Further Reading

Hothfieldmemories.org.uk. (2016). Conservation of the bogs and heathlands | Hothfield Common - a unique heathland environment | Places | Hothfield Memories. [online] Available at: http://www.hothfieldmemories.org.uk/page/hothfield_common_-_a_unique_heathland_environment [Accessed 6 May 2016].

QUESTION; Describe how a coppice system might have operated in medieval times

Coppicing is an old method of producing a crop timber from a woodland. A tree grows from it's top producing side shoots at intervals from the main stem. If dominant buds are removed, this then stimulates new growth from the base.

coppicing was used in medieval times however not like it is today, it was operated to produce a crop of wood of different ages. Five year old coppice would be used for sheep hurdles, hedging stakes and thatching spars. All older wood could be used for fencing material, furniture and firewood as it lasted longer then developing wood. The cutting of different areas at different times produced age structuring.

Some trees were left to grow and produce larger timber these where known as "standard" trees today called Oak trees. These provided wood for houses and ships timber as it was more strongly built. As the trees are cut and removed from the wood, glades are created. Without the shade created by the trees, sunlight penetrates to the woodland floor promoting the growth of the woodland flowers such as bluebells and orchids.

Figure 1. showing stages of Coppice Development
(A guide to maintaining coastal bluff stability, 2016) 

As the coppice grows the plants that flower early will persist, whilst others are shaded out. After five years bramble and ivy have covered the woodland floor. However, with the decline of the flower comes and increase in mammal and bird life. Woodcock and Nightjar will nest in the glades created by coppicing and, as the trees grow, pheasant and nightingale, which prefer five to seven year growth, will come.

References;

A guide to maintaining coastal bluff stability. (2016). Recommendations. [online] Available at: http://wiblufferosion.weebly.com/recommendations.html [Accessed 5 May 2016].