Monetary value

Monetary value for what?? money ? income ? or else..

While it is difficult to establish the net value of a species, it can be estimated.

The Amazon Rainforest is a well known biodiversity hotspot.

In Cape Province, South Africa the native vegetation of the area is the fynbos, a type of shrub. The fynbos are able to survive long periods of drought, periodic fires, and poor soil conditions; the plants are harvested annually with annual a yield of about $19 billion. Recently exotic plants have threatened the endemic fynbos. The new plants grow larger; increasing the severity of periodic fires. More importantly they transpire more water; reducing the local streams to half their normal water flow.

Removing the exotic species will cost between $140 US and $830 US per hectare and $8 US per hectare to maintain every year after. Alternatively, a sewage purification plant would cost $135 million US to build and $2.6 million US per year to maintain. Desalination of surrounding coastal waters would cost four times as much.