National Inventories of Landscapes in Sweden: NILS Inventory 2003–2020

Dataset type

This dataset that contains event based data for species which may include sampling information

Description

The NILS Inventory 2003–2020 is the original NILS landscape monitoring programme, conducted from 2003 to 2020, and encompassed all terrestrial environments in Sweden, including both lowland and alpine areas (lowland until 2018; alpine until 2020). The programme was established to monitor biodiversity across the Swedish landscape and to track long-term changes in the everyday landscape. A central component was to assess changes in landscape composition and structure, and the prerequisites for biodiversity.

In years 2003–2018 data were collected nationwide, from 2019-2020 data collection continued only in alpine areas.

The true coordinates of the permanent sample plots are protected. The coordinates in this dataset are generalised, by randomly offsetting true coordinates with 200-2000 m. See also Additional Information.

The original NILS Inventory has been replaced and extended by five separate inventories specifically adapted to the different landscape types: the NILS Alpine Inventory (initiated 2021), NILS Deciduous Forest Inventory (initiated 2020), NILS Grassland Inventory (initiated 2020), NILS Wetland Inventory (initiated 2023) and the THUF Seashore Inventory (initiated 2012). Data from those inventories will be published in separate datasets and can currently be accessed only directly from the organisation.

Geographic Description

NILS data are collected across the whole of Sweden, including alpine, lowland, forested, grassland, and wetland landscapes. The sampling design ensures national representativeness, covering both protected and unprotected areas.

Purpose

The purpose of the NILS programme is to describe the state, distribution, and long-term changes of terrestrial habitats in Sweden. By monitoring biodiversity, landscape composition and structure, and land-use impacts, the programme provides essential information for assessing habitat quality, following biodiversity trends, supporting conservation management, and meeting national and EU-level environmental reporting and policy needs.

Data quality

All data collected within the NILS programme undergo multiple stages of quality control to ensure accuracy and consistency. For the original NILS programme (2003–2020), quality control procedures included cross-checking field data against distribution maps and other reference materials prior to long-term storage and analysis.

Methods

In Phase 1, the primary sampling units (“tracts”) are selected from a national sampling frame consisting of all 1 × 1 km grid cells containing land or freshwater within Sweden. Tracts are chosen using coordinated and balanced sampling procedures, ensuring broad spatial representation across environmental gradients. Once selected, each tract contains a systematic arrangement of circular sample plots, which form the basis for Phase 2.Phase 2 consists of two steps.

Phase 2 - Step 1 is a remote-sensing–based classification of all sample plots within each tract. Depending on the inventory, this step may rely on manual aerial photo interpretation, automated model-based predictions, or a combination of both. The purpose of this step is to identify plots where target habitats are likely to occur and to exclude plots or entire tracts that certain lack such habitats. Plots are assigned to selection classes that determine their eligibility and priority for field surveys.Phase 2 - Step 2 consists of conducting field surveys in the subset of plots selected from Step 1. The selection is random but stratified by the classification results, giving all potentially relevant plots a non-zero probability of inclusion. This design allows rare habitats to be sampled at higher density while keeping overall field effort feasible. Field teams collect detailed information on vegetation structure, species composition, and habitat condition, enabling refined classification and ecological assessment.

Type of content

Includes: Point occurrence data.

Citation

Hedenås H (2026). National Inventories of Landscapes in Sweden: NILS Inventory 2003–2020. Version 1.2. National Inventories of Landscapes in Sweden, Department of Forest Resource Management, SLU. Samplingevent dataset. https://www.gbif.se/ipt/resource?r=nils-event&v=1.2

Rights

To the extent possible under law, the publisher has waived all rights to these data and has dedicated them to the Public Domain (CC0 1.0). Users may copy, modify, distribute and use the work, including for commercial purposes, without restriction.

Digitised records

Metadata last updated on 2026-03-09 03:03:35.0