Glossary

Key terms and definitions used throughout the Forestry Catchment Planner documentation.

Term	Definition
Forestry Catchment Planner (FCP)	A tool to visualise underlying geospatial data for managing plantation forests and clearfell harvesting on erosion-susceptible lands.
Window of Vulnerability	The period of 6-8 years post-clearfell harvest during which land is more susceptible to erosion due to the loss of tree root reinforcement and canopy cover.
Root Reinforcement	The soil reinforcing effect of a forest’s root network, which helps to bind soils together and anchor them to the underlying rock formation.
Umbrella Effect	The interception and evaporation of rainfall by a forest canopy, which helps keep forest soils drier and stronger than soils under shorter vegetation.
Catchment Management Units (CMUs)	Subcatchments within a larger catchment area used to manage and visualise the effects of clearfell harvesting.
Hillslope Units (HSUs)	Smaller divisions within CMUs that represent areas similar in erosion susceptibility, typically in first or second-order subcatchments.
Rainfall-Induced Landslide (RIL) Susceptibility Model	A model developed by GNS Science to predict the spatial probability of landslides triggered by rainfall events.
Melton Ratio (Melton-R)	A measure of a catchment's average steepness or ruggedness, used to classify debris flow susceptibility.
Erosion Susceptibility	The predisposition of a land unit to erode, determined by its soil characteristics, geology, and topographic features.
Mass Movement Erosion	Erosion types where material moves downslope as a coherent mass under gravity, including soil slips, debris flows, and earthflows.
Fluvial Erosion	Erosion involving the removal of soil material by running water, such as gully erosion.
Land Use Capability (LUC)	A classification system used to distinguish between different erosion processes and land units in New Zealand.
Sediment	Particles of soil, sand, and minerals that are transported by water or wind and deposited in a new location.
Landslide	The movement of rock, earth, or debris down a sloped section of land.
Debris Flow	A type of landslide involving the rapid flow of soil and rock mixed with water down a slope.
Soil Slip	A shallow, rapid slide and flow involving soil and underlying weathered rock.
Earthflow	The slow movement of soil and regolith, usually along deep shear planes, often creating a hummocky surface.
Gully Erosion	The removal of soil material by channelized running water, leading to the formation of gullies.
Fluvio Gully-Mass Movement Complexes	Large gullies that involve both fluvial and mass movement erosion processes, common in the Tairāwhiti/Gisborne-East Coast region.
Lidar	A remote sensing technology that measures distance by illuminating a target with laser light and analyzing the reflected light.
Geospatial Data	Information that is associated with a specific location on the Earth's surface.
Clearfell Harvesting	The practice of cutting down and harvesting all the trees in an area at once. The minimum for a clearfelling area is 0.25 ha but clearfelling areas can extend over many hundred of contiguous hectares.
Social Licence to Operate	The ongoing acceptance and approval of a company's activities by local communities and other stakeholders.
Tino Rangatiratanga	The exercise of absolute chieftainship, often associated with Maori sovereignty and self-determination.
Mana Motuhake	The principle of self-determination and autonomy, particularly for Maori communities.
Throughfall	The process by which precipitation passes through the canopy of a forest or vegetated area and reaches the ground, either directly through gaps or by dripping off leaves and branches.