Vietnam High Conservation Value Forest Toolkit - HCV Resource ...

HCV 4: Forest areas that provide basic services of nature in critical situations.
Definition
This value is concerned with environmental services of forests, their role in regulating climate,
water flow and other essential services of nature. Unlike HCVs 1 – 3 that could only be used
for natural forests, HCV 4 could be applied for both natural forests and planted protection
forests.
In recognition of the environmental services of forests, HCV 4 is divided into several elements
(HCV 4.1 – 4.2), all of which need to be assessed to determine whether and area is HCVF.
HCV 4.1: Forests critical to the maintenance and regulation of water sources for drinking
and irrigation.
Forests play a critical role in controlling water flow and supply, possibly on a large scale where
whole valleys and catchments regulate the flow of water into river systems. This element
however should also be seen on a small scale where a forest area might represent the only
source of drinking and cooking water for a community. Loss of the forest cover may
irreparably damage the water supply.
An area is HCVF only if the water supply or catchment is essential. Loss of this water supply
will have drastic impacts on a community or communities. In some situations this element
could also be referred to as HCV 5 whilst assessing community’s access to sources of drinking
water. HCV 4 is more concerned with if a source of water is used for irrigation purposes.
HCV 4.2: Forests critical to the prevention of landslide, flash floods, soil erosion, storm
wind, sedimentation and protection of coast lines.
Forests play a roll in stabilizing land. The vegetation cover can reduce the direct erosion from
rain fall, and the binding of roots and plant matter can secure soils preventing landslides. This
too can be viewed at two scales: at a large scale, erosion and the silting up of river and
irrigation systems can effect agriculture, fisheries and marine ecosystems; at a local scale,
forest cover may prevent landslides and the erosion of farming or residential land, the cutting
of communications (roads, power, phones, etc), or the filling up of irrigation structures.
In terms of protection of coast lines, forest is critical to mitigate negative impacts caused by
storms, sand wind, tidal waves and tsunami.
Forest that possesses one or more important functions mentioned above is considered a HCVF.
Instructions to user
4.1: Forests critical to the maintenance and regulation of water sources for drinking and
irrigation.
Possible indicators / sources of information:
• Scale and nature of the area (topography, area, catchment, river system, etc?)
• Location and degree of protection by the forest area (upstream/downstream, extremely
critical/critical/less critical?)
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