Heath Model

Slide 1: 

Presentation of Heath Model Case study module 5 NRM by Tumwesigye Wycliffe 240221 & Tesfaye Ayele Yimam 09907

Context of the Heath Model : 

Context of the Heath Model The dwarf shrub heather Calluna vulgaris is an important component of the UK landscape Its main value is for amenity, nature conservation and animal production.

Context of the Heath Model Contd : 

Context of the Heath Model Contd Sheep grazing and burning are used to manage heather in the area Grazing may have different impacts on the productivity of heather, depending upon the intensity, duration and timing of the grazing (Grant et al., 1982).

Purpose of the model : 

Purpose of the model The model was developed to predict the seasonal and annual impact of sheep grazing on heather in UK uplands. It was applied to identify sustainable grazing levels on heather in UK uplands

Slide 5: 

HEATH LAND Heather Sheep Potential annual Shoot Production Current Season’s Shoot Production Current Season’s Shoot Mass Previous Season’s Shoot Mass Sugar Pool and Litter fall Total Number Grazing Intensity Conceptual Diagram Manure Grazing Sheep Sheep- Products Climate Soil nutrients Management Amenity Production Services Energy

Model Structure : 

Model Structure Wycliffe Tumwesigye and Tesfaye AyeleYimam MSC in NRM 2010

Emergent properties : 

Emergent properties Land degradation and loss of heather on log-term sheep grazing Establishment of sustainable levels of sheep grazing on heather land in UK landscape

Determining sustainable grazing levels on heather : 

Determining sustainable grazing levels on heather Fig 2. Grazing at 20% Fig 1. No grazing Grazing at 20% beyond 7.5 years seemed to degrade heather beyond sustainable levels (Fig 2) Both sugar pool and current shoot production grow to maximum if no grazing occurs (Fig 1)

Research Questions : 

Research Questions What percentage of sheep grazing allow long- term persistence of heather? What percentage of sheep grazing prevent long-term persistence of heather?

Testable Hypotheses : 

Testable Hypotheses Ho: There is no significant difference between 40% and 80% grazing levels on the shoot dry mass of heather produced per square meter in winter season Ho: There is no significant difference between 40% and 80% grazing levels on the shoot dry mass of heather produced per square meter in summer season Ho: There is no significant difference between 40% and 80% grazing levels on the shoot dry mass of heather produced per square meter per year

How to test the hypotheses : 

How to test the hypotheses Statistically test the differences in means of the shoot dry mass of heather produced per square meter at 40% and 80% grazing levels in summer Statistically test the differences in means of the shoot dry mass of heather produced per square meter at 40% and 80% grazing levels in winter Statistically test the differences in means in the shoot mass of heather produced per square meter at 40% and 80% grazing levels per year

Sensitivity Analysis : 

Sensitivity Analysis Grazing levels and soil types were the two parameters we tried to test No meaningful conclusions were made Possible reasons: Some equations used in the paper did not work in Stella Limited time factor

CONCLUSION : 

CONCLUSION THANKS YOU FOR PROTECTING HEATHER!