生物与生命科学
已验证计算器，公式透明
Species-Area Relationship Calculator.
Estimates the number of species expected in a habitat of a given area using the power-law species-area relationship S = c * A^z.
您的输入
工作原理
- 1
Enter the area of the habitat in square kilometers.
- 2
Enter the constant c, which represents the number of species per unit area.
- 3
Enter the exponent z, which describes how species richness scales with area.
- 4
The calculator applies the formula S = c × A^z to estimate the number of species.
c * pow(area, z)常见问题
What does the exponent z represent?
The exponent z is the slope of the species-area relationship on a log-log plot. It typically ranges from 0.15 to 0.35 for most habitats, with higher values indicating steeper increases in species with area.
What is the constant c?
The constant c is the number of species expected in one unit of area (e.g., 1 km²). It varies by taxonomic group and region.
Can this calculator be used for conservation planning?
Yes, it helps estimate species loss when habitat area is reduced, which is useful for reserve design and impact assessments.
工作原理
Estimates the number of species expected in a habitat of a given area using the power-law species-area relationship S = c * A^z.
- Enter the area of the habitat in square kilometers.
- Enter the constant c, which represents the number of species per unit area.
- Enter the exponent z, which describes how species richness scales with area.
- The calculator applies the formula S = c × A^z to estimate the number of species.
公式
此计算器背后的数学公式，供您核对结果。
Power-law species-area relationship
S is the number of species, A is the area, c is a constant, and z is the scaling exponent.
Example:
Input: A = 100 km², c = 10, z = 0.3
Calculation: 10 × 100^0.3 ≈ 10 × 3.98 = 39.8
Result: ≈ 40 species
实际应用场景
此计算在日常生活中的应用。
Habitat fragmentation
Estimate how many species might be lost when a habitat is reduced in size.
Example: If a 100 km² forest is cut to 10 km², species drop from 40 to about 20.
Island biogeography
Predict species richness on islands of different sizes.
Example: Compare a 5 km² island to a 50 km² island.
Reserve design
Determine the area needed to support a target number of species.
Example: Find the area required for 100 species given c and z.
提示与常见错误
Tips
- Use typical z values: 0.15 for mainland, 0.25 for islands, 0.35 for isolated habitats.
- Ensure area units are consistent (e.g., all in km²).
- The relationship is a power law, so log-log plots are linear.
- For small areas, the estimate may be less accurate due to sampling effects.
Common Mistakes to Avoid
- Using z as a percentage instead of a decimal (e.g., 0.3 not 30).
- Forgetting to convert area to the same units as c.
- Assuming the relationship holds outside the range of observed data.
假设与限制
- Use the stated inputs and units.
- Results are estimates for planning and education.
- Check measurements and source data before making an important decision.