List various ecological services.

(N/A) Healthy ecosystems are the foundation for a wide range of economic,environmental,and aesthetic goods and services.
The products of ecosystem processes are known as ecosystem services. For example,healthy forest ecosystems purify air and water,mitigate droughts and floods,cycle nutrients,generate fertile soils,provide wildlife habitat,maintain biodiversity,pollinate crops,provide storage sites for carbon,and also provide aesthetic,cultural,and spiritual values.
Robert Constanza and his colleagues have recently attempted to put price tags on nature's life-support services.
Researchers have estimated an average price tag of $US$ $33$ trillion a year for these fundamental ecosystem services,which are largely taken for granted because they are provided free of cost.
This is nearly twice the value of the global Gross National Product $(GNP)$,which is $US$ $18$ trillion.
Out of the total cost of various ecosystem services,soil formation accounts for about $50\%$ of the total,while the contributions of other services like recreation and nutrient cycling are less than $10\%$ each.
The cost of climate regulation and habitat for wildlife are about $6\%$ each.