NILS Grassland Inventory

The Purpose of Our Inventory: 

The NILS Grassland Inventory is a nationwide general inventory of all types of grasslands, with a particular emphasis on natural habitats with high ecological value (as identified in Annex 1 of the EU's Habitat Directive). This inventory will allow for the estimation of the various types of grasslands and an assessment of their quality. Together with NILS alpine inventory, where grasslands in the alpine area are inventoried, the inventories cover all types of grasslands in Sweden. 

The task of inventorying grasslands in general and specifically in agricultural landscapes was already present in the NILS 2003-2020 inventory, but the sample size was too small to obtain good data for more than the most common types of grasslands and species. Therefore, the NILS Grassland Inventory was initiated to conduct a targeted inventory of grasslands. 

What We Inventory: 

The grassland inventory encompasses all land types, below the alpine area where the field layer is dominated by graminoids, herbs, or dwarf-shrubs, that are not classified as either forests or peatlands. The grasslands may be either open or wooded, and include traditionally managed natural lands, meadows, heaths, rocky outcrops, and cultivated pastures and hayfields. Additionally, it includes naturally open grasslands, like flood meadows, as well as lands that remain open for reasons other than fodder production, such as grasslands on power line corridors, airports, sports facilities, golf courses, ski resorts, shooting ranges, parks, residential properties, roadside verges, overgrown quarries, and the like. Lawns and extensively managed grasslands, which are cleared and mowed a few times a year or at intervals of a few years, are also part of the inventory. 

Wooded grasslands are also included, regardless of the tree species composition, whether the tree layer is dominated by conifers or deciduous trees. Trees with crown-topped pasture or parkland trees may be present. The vegetation may be affected by contemporary or historical mowing, and the presence of traditionally pruned trees (e.g., pollards) may be noticeable. The classification of grassland stands as long as grass (sod) is present, regardless of whether it starts to be overgrown by trees or shrubs or not.