Spatial Statistics For Habitat Analysis Of Thurstaston Common

Use the final map produced using GIS to determine a range of spatial statistics (see list below) associated with each habitat you have recorded and include these estimates in a table in your survey report. Mean (±SD) calculations should reflect differences between the recorded habitats. These data can be used to help you describe the spatial composition and configuration of the habitats across the site. These data should be presented as Table 1a and 1b (see examples below).

Required spatial statistics (include those marked in orange in Tables 1a and 1b):

1. Area (units = hectares, units required for Phase 1 Maps) of each polygon

o sum to get the total area of each habitat at the site

o calculate the percentage of site made up by different habitats

o calculate the mean (±SD) patch size for each habitat at the site

o sum the no. of patches (those not connected) for each habitat at the site

2. X and Y coordinates of polygon centroids

o X coordinate (include one from a patch of our choice of each habitat type)

o Y coordinate (include one from a patch of our choice of each habitat type)

3. Perimeter length (units = metres) of each polygon

o sum to get the total perimeter length of each habitat at the site

o calculate the mean (±SD) perimeter length for each habitat at the site

4. Habitat Edge Density (units = m/ha) (total perimeter length of each habitat at the site, divided by the total landscape area (ha))

o calculate the Habitat Edge Density for each habitat at the site

5. Area (units = square meters, required to calculate Perimeter-Area Index) of each polygon
6. Perimeter-Area Ratio (divide Perimeter by Area) of each polygon

o calculate the mean (±SD) Perimeter-Area Ratio for each habitat at the site

7. Shape Index of each polygon (perimeter (m) * 0.25 (shape adjustment constant) divided by the square root of patch area (m2)

What are the strengths and

weaknesses of this method?

Is it reliable enough to use for conservation management and planning purposes? How could it be improved?

Compositional and Configurational landscape matrix

As per Wikipedia (2018), Thurstaston Common spreads over 200 acres of the land. Most of the parts of the place are covered with Parklands.

While both Scientists and the historians have always been keen to know more and more about the place due to its Scientific values provided by Common and the aesthetic value provided by the Thurstaston hill sites.

Here we have made an attempt to critically inspect the survey conducted at the ground level to obtain the map that could be further utilised to understand the growing situations of th various habitats in the region.

Our objective would be to recognize the geometrical patterns like the location and area measurements of the various habitats so that the quantitative analysis can be performed.

Based on these parameters the further steps can be decided like which habitat is growing at its own and doesn’t need any special care or the support. As suggested by Gilliland et al. (2008) these small scale maps can be used to analyze the large scale research.

Habitat Name	Name Habitat code	No.  of patches per habitat	Total habitat area(h)	Proportion of site (%)	Mean habitat patch size (h)	Sample Polygon centroid     (X)	Sample Polygon centroid     (Y)
Broadleaved woodland - semi-natural	A1.1.1	19	245461.2023	42.23091887876961	12919.01064	324366.7932	385200.9536
Improved grassland	B4	3	48320.02552	08.31332633766374	16106.67	324605.6951	385111.7986
Bracken - continuous	C1.1.	13	120317.641	20.700316339793	9255.203153846154	324364.8857	385174.7269
Dry dwarf shrub heath - acid	D1.1	31	56170.97	09.66405955476655	1811.966774193548	324340.0878	385118.4123
Montane heath/dwarf herb	D4	1	826.919227	00.14226915890378	826.919227	324478.5845	384930.6907
Standing water - eutrophic	G.1	2	5411.787748	00.93108306825444	2705.893874	324647.7074	385159.1935
Cultivated/disturbed land - amenity grassland	J1.2	2	101643.544	17.48748975802865	50821.772	324190.7203	385321.4074
Buildings	J3.6	3	3083.67	00.53053686855055	1027.89	324417.9092	385246.0521

The following table shows the matrix form of the map and the data collected in the real time survey. The habitat name and the codes are unique identifications assigned to each of those. The centroid for each habitat type of have been calculated by the formulae mentioned later on in the description

Table 1.1 The configuration matrix

List of Target Notes and Descriptions

Grid Reference	Habitat Type(s)	Dominant Species	Other species	Recommendation (further survey, management, est.)
SJ 24472 BNG 84730	(1) Dry dwarf shrub heath - acid	Heather and bracken	Goarse and Silver birch	Heather is invaded by bracken
SJ 24395 BNG 84774	(2) Dry dwarf shrub heath - acid	Heather and bracken	Goarse, Silver birch and rhododendron	Heather is invaded by bracken and rhododendron, manage the invasive species
SJ 24360 BNG 84975	(3) Broadleaved woodland - semi-natural	Silver birchand bracken	Bracken, scots pine	Silver brich is invaded by bracken
SJ 24373 BNG 84975	(4) Dry dwarf shrub heath - acid	Heather and bracken	Goarse	Heather is invaded by bracken , manage the invasive species
SJ 24373 BNG 84975 72m	(5) Improved grassland	Grass and Molinia caerulea (Purple moor grass)	Juncus effusus , bracken	Remove the invasive species- bracken
SJ 24266 BNG 85203 60m	(6) Broadleaved woodland - semi-natural	Silver birch and betula pendula	Oak, scots pine and bracken	Remove the invasive species- bracken

Table 2.1 The Target Notes

There is a famous law known as the “Law of Nature” which always determines the growth of various habitats in any particular area as suggested by Rees et al.(2015). The region may be the bounded one or the opened one, this particular rule will definitely hold true when applied to the real case scenario for the growth and development of the different types of habitats together being the neighbourhood and in the close proximity.

Even if just have a generalized look at the map and distribution that we have got it is clearly evident that the habitats have shown the growth and breed trajectories based on the various factors that may or may not be of the local nature. Though, now a days with the outreach possibilities of the technology to each and every part of the part the chances for the real time local data understanding has become quite precise, we still use the various statistics and mathematical models to study the habitats and their growth for a particular geography. Also as per Lieberknecht et al. (2008 p.88) the habitats may reflect this behaviour in ecology.

It is obvious from the map that the habitat, ”Broadleaved woodland - semi-natural”  occupies the major chunk of the area. The land cover is almost two third of the land are. The green patch on the map appears upfront with the total area of 245461.2023 hectare with 19 various recognized Polygons.

The polygons have been decided based upon the criterion that any enclosed area with the same type of habitats bounded by any number of various habitats (other than itself).

Description of the Habitat

Similarly “Bracken – continuous” habitat and “Dry dwarf shrub heath – acid” also occupy a major portion of the space with around one-fifth and one one-tenth having their respective shares.  The matter of immense criticality starts for the habitat, “Montane heath/dwarf herb” which occupies as little as the one-thousandth of the available geography.  On the same line, “Buildings” and “Standing water – eutrophic” have shown the sluggish spreading.

There is a special method that has been applied to obtain the centroid coordinates for each of the axes. Here, the North- South being Y axis and the East- West means X axis. There has been an advantage of fragmentation of each habitat in to the possible number of Polygons. This has increased the possibility and chance of the statistical data to lead to the real time scenario. With each recognizable Polygon with the visible boundaries the geometric centres have been located. Afterwards, Horizontal and the Vertical point of references have been decided. This may be any bay or any fixed land form which would not change for quite some time. The centroid coordinates for each polygon have been recognized for each type of habitat with the most accurate methods.

Afterwards, the formula of the centroid for each habitat has been used to obtain the imaginary centroid for each habitat.

He formulae used is

Where,  X is the X coordinate of the overall habitat  is the X coordinate of the Polygon 1 and the same continue till n number of the polygons for each type of the habitat. represents the area of the Polygon 1 of the same habitat and the same continue till n number of the polygons for each type of the habitat.

Polygon 1 of the same habitat and the same continue till n number of the polygons for each type of the habitat.

A careful look at the overall centroids and the separate centroids of almost all the habitats reflects the density concentration of each habitat in the cluster. Actually the overall centroids are almost having the same range of values as the separate centroids. This shows that the particular habitat doesn’t have the polygons that are very far away from each other and this becomes more and more same as the proportion of the habitat in comparison to the total available land decreases.

It actually sounds logical as the increased proportion will demand more spreading of the area polygons and thus the values of the centroid coordinate will be more deviated from the imaginary value of the centroid assuming that the whole area is taken as one big Polygon having the area equal to the sum of the areas of the fragments of the polygons.

The map also shows the presence of the corridors for the various habitats. It’s quite natural that a buffer will always exist between any two habitats. There are no such physical boundaries which can reflect that the habitat one is finished and from here the habitat 2 is started. Like every other thing in the nature this also occurs with a gradual pace. As we move from one habitat to another, the ambience and the ecosystem including the biotic and abiotic components of that habitat keep on changing. There is general shifting pattern which shows the mixture of the species and feature of both the habitats. This region where two habitats meet and create a gradual changing pattern from one habitat to another is buffer area. This has always been of critical importance in the world of geography. It’s is this area which determines the various species belonging to the habitat to be in the captivity without the real physical boundaries and keep a check o their behavior and well being so that the ecosystems that are formed both locally and globally should prevail without the much disturbances

Evaluation of the Methodology

The method used has the two significant aspects:

1. The real time Physical Survey.
2. The mathematical model to reach to the data with statistical approach

The map obtained is based on the real time data collected from the on field survey of the land or the area being inspected. Assuming that the survey is conducted with the least possible errors the raw data generated is actually provided by the image of this map only.

Some of the critical parameters that should be taken care of while conducting such surveys are:

• The thickness of the boundaries
• Tri junctions
• Exploring the buffers

Thickness of the Boundaries

In nature there doesn’t exist the actual physical one dimensional boundary lines. There is always some good amount of the thickness in the boundaries where the two habitats meet. This is critically important as sometimes the thickness may become too large to be avoided and excluded from the map as a separate entity. The polygons formed in the current model include this point as one of its integral part in the map.

At some places the three habitats meets and the tri junctions are formed. These points and the locations should be very carefully determined and the specific changes and data are to be collected. Also as per DEFRA (2014 p.170) the various biological or the ecological zones combine at their boundaries and these combinations sometimes yield the results that can be use to obtain the large scale ecological maps and situations.

Buffers always exist whenever there is an existence of the boundaries. The only important thing for nay survey is to deeply include the observation made in the buffer to make the least possible assumptions. Here, in this model we have sub divided each habitat in to various polygons of the smaller sizes thus the buffer is to be taken care of at the boundaries of two different habitats.

The mathematical practices used here in this work are reliable. As we have not made much assumptions. Only the certain tools of statistics have been used to average the data and have the required imagination and visualisation of the overall scenario with a broader sense.

For example, the overall centroid for a habitat doesn’t have any physical existence. But it shows the distribution pattern of a particular habitat with respect to the other habitat.

Conclusion

Thus the process used is found to be a satisfactory one in inspecting the geography of a land and then proceeding with the required steps to be taken to control and change the current situation. The very first step of surveying and generating the map as per the requirements and afterwards using the data and map to analyse the condition by some simple mathematical tools has also been used in a decent way. Based on the risks present for various species the appropriate steps can be taken JNCC Report (2016) also suggests some very useful and appropriate methodologies to execute any such plan. There are various other ways as suggested by McLeod et ad. (2007 p. 540) that could be applied to contain and re-establish the ecosystems as per the requirements of the system and the expected levels.

References

En.wikipedia.org. (2018). Thurstaston Common. [online] Available at: https://en.wikipedia.org/wiki/Thurstaston_Common [Accessed 25 Dec. 2018]. 

 En.wikipedia.org. (2018). National trust. [online] Available at:    https://en.wikipedia.org/wiki/National_trust [Accessed 25 Dec. 2018].

Coltman, N., Golding, N. and Verling, E. (2008) Developing a Broadscale Predictive EUNIS Habitat Map for the MESH Study Area. 16p.  https://www.searchmesh.net/pdf/MESH%20EUNIS%20model.pdf [Accessed 25 Dec. 2018].

Cherrill, A. and McLean, C. 1999. Between-observer variation in the application of a standard method of habitat mapping by environmental consultants in the UK. Journal of Applied Biology 36, 989-1008

Gilliland, P.M. and Laffoley, D. (2008) Key Elements and Steps in the Process of Developing Ecosystem-Based Marine Spatial Planning.

Rees, S., Foster, N., Langmead, O. and Griffiths, C. (2015) Ecological Coherence of the MPA Network in the Celtic Seas

Lieberknecht, L.M., Mullier, T.W. and Ardron, J.A. (2014) Assessment of the Ecological Coherence of the UK’s Marine Protected Area Network. A Report Prepared for the Joint Links, 88 p.

DEFRA (2014) South Inshore and South Offshore Marine Plan Areas: South Plans Analytical Report (SPAR) June 2014. 170 p

McLeod, H.M. and Leslie, K.L. (2007) Confronting the Challenges of Implementing Marine Ecosystem Management.Ecology and the Environment, 5, 540.