Grassland connectivity model
The first version of GrassLIFE connectivity model is based on the data about grassland habitats on national scale that is available in various databases (mostly Ozols, also dabasdati.lv etc.) and data sets that were developed by IES by using Sentinel-2 satellite 2017 data. This work involved three remote sensing data experts, doing satellite data processing, algorithm development, the map production and data verification at first for smaller case area (100x100km, 17% of Latvia area) and later for all Latvia.
As a result of overlaying different data sets, we have obtained the grid of grasslands and ranked them in accordance to their priority for ensuring the grassland connectivity. The first version of the model was circulated within project consortium and used for supporting the decisions on prioritising the project restoration sites (especially for the decision making process for action C.3).
The second version of the connectivity model was built by adding the data from nationwide habitat mapping and delivered in 2022.
Different connection distance thresholds produce different results and Version 1 of the connectivity model experiments with five different thresholds, from 5 km to 100 meters. Please see the below table that summarizes the connectivity results for each of the thresholds.
Connection distance threshold | Number of connected patch networks | Number of patches (nodes) in the largest network | Area of the largest network (ha) | Number of patches (nodes) in the 2nd largest network | Area of the 2nd largest network (ha) |
5 km | 157 | 3190 | 13080,0227 | 1308 | 6195,3599 |
1 km | 2145 | 84 | 4152,8568 | 213 | 2821,9083 |
500 m | 3421 | 74 | 4076,8898 | 165 | 2646,7516 |
200 m | 4925 | 68 | 4026,6685 | 131 | 2585,7035 |
100 m | 6012 | 63 | 3958,5933 | 56 | 1341,2611 |
In the below pictures we have visualised three of the scenarios: 1 km threshold, 500 meters and 100 meters thresholds. Given the scale of the exercise, we did not produce the map in high resolution for all the scenarios. For demonstration purposes, we have produced two high-resolution photos with all the grassland patches identified, and classified according to their importance and connectivity potential for 100 m and 1 km thresholds. Those can be seen below.
Picture 2. All the grassland patches in Latvia identified, and classified according to their importance and connectivity potential for 1 km threshold.
First version of the connectivity model was presented at the LIFE Platform meeting “Lessons from LIFE on ecological connectivity towards a coherent, functional and resilient network of protected areas” on 2-4th March 2021. Please see the short presentation here.
