Patch Shape Analysis

Patch Shape Analysis
Patch Shape Analysis

Ukuran dan bentuk PATCH merupakan atribut penting yang mempengaruhi aliran (FLUXES) abiotik dan biotik pada persepektif Landscape Ecology. Pada lanskap alami umum dijumpai bentuk REGULAR dan IRREGULAR. Semakin irregular semakin banyak EDGE yang tersedia. Hal ini mempunyai implikasi yang sangat besar terhadap penyebaran tanaman dan pergerakan hewan.

Dengan menggunakan ratio L/2AkarAPhi, di mana L = keliling patch dan A = luas patch, dimungkinkan untuk mengevaluasi jumlah dari “edges”. Lingkaran mempunyai nilai Patch Shape dan menerangkan gambar geometrik dengan ratio minimum antara keliling dan area. Dalam formula matematikanya menjadi PS=(2P+2L)/(2*SQRT(P*L*PI)).

 

Effect PS on Species

  • Large islands have more species than small islands.
  • Mountainous islands have more species than flat island of the same size.
  • Island with evidence of considerable human disturbance activity often have fewer species than those without such activity.
  • Relationship between species diversity and island size is not linear, but CURVILINEAR.
  • The relationship plotted between increasing area and the number of species is called a SPECIES-AREA CURVE
  • Patches in the landscape differ significantly from islands surrounded by water.
  • Landscape patches may high average turnover rates, whereas island are essentially permanent.
  • The landscape matrix often has extremely high heterogeneity.
  • The landscape matrix may be used as a rest stop for many species moving between patches, particularly in the limited area of a landscape compared with the extensiveness of oceanic archipelagos.

 

Patch Shape Analysis

1. Berapa nilai PATCH SHAPE dari patches regular berikut?

2. Patch nomor berapakah yang lebih tahan terhadap disturbance?

Patch

No.

Panjang

(m)

Lebar

(m)

1 150 200
2 200 200
3 300 200
4 500 200
5 1000 200

 

Jawaban:

  1. Nilai Patch Shape (PS) adalah sebagai berikut:
Patch No Panjang (m) Lebar (m) A (m2) L (m) A*phi Patch Shape
1 150 200    30.000     700    94.247,78 1,14007
2 200 200    40.000     800  125.663,71 1,12838
3 300 200    60.000  1.000  188.495,56 1,15165
4 500 200  100.000  1.400  314.159,27 1,24889
5 1000 200  200.000  2.400  628.318,53 1,51388

2. Berdasarkan nilai PS pada tabel di atas, maka patch yang paling tahan terhadap gangguan yaitu Patch No 5, kemudian Patch No 4, 3, 2 dan terakhir No 1.

 

Cara Perhitungan di Excel

Patch Shape Analisys

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