Vegetation Heights 2020
The classification process was carried out for the entire mosaic of the 2020 true orthophotos. Figure 6 presents a section of the result of the classification in the Großer Tiergarten area.
Some 56,000 ha of the entire urban area are covered with vegetation. For a total area of about 89,100 ha, this corresponds to a percentage of approx. 63 %. It is important to note here that the vegetation is analysed in plan view, due to the use of remote sensing data. This means that areas covered with vegetation also include areas that are impervious underneath the vegetation cover, e.g. yards that are covered with trees but are largely paved. Areas covered with vegetation are therefore not the same as vegetated soil.
A comparison with the area sizes of those block (segment) areas that have been categorised as purely green and open space use in the Urban and Environmental Information System (ISU) (Map “Inventory of Green and Open Spaces” (06.02), Tab 2, SenStadtWohn 2020b) shows that about 19,000 ha of vegetated areas are located outside the “traditional” green spaces, i.e. on road areas and in areas associated with structural uses. This accounts for roughly 54% of the total of 35,000 ha of green and open spaces according to the 2020 ISU and illustrates the substantial resources of urban green space in Berlin’s residential areas, but also in other built-up areas of the city.
Comparing the absolute sizes of areas covered with vegetation in the 12 boroughs of Berlin, it is evident that the largest such areas are also found in the boroughs with the largest total area that are located outside the City Rail Circle Line. These boroughs contain large forest areas, e.g. the Köpenicker Forst in Treptow-Köpenick, the Bucher Forst in Pankow, the Spandauer Forst in Spandau, the Tegeler Forst in Reinickendorf and the Grunewald in Steglitz-Zehlendorf and Charlottenburg-Wilmersdorf (cf. Figure 7, sorted according to the borough numbering system based on the Verwaltungsgliederung (administrative division) of Berlin.).
The distribution (in percent) of vegetated areas in Figure 8 reveals that more than 50 % of almost all boroughs are covered with vegetation. Again, it should be noted that the area covered with vegetation was recorded in plan view and is not the same as pervious, vegetated soil. The area covered with vegetation drops below 40 % only in the inner city boroughs of Friedrichshain-Kreuzberg and Mitte.
It is worth noting that even in the inner city, not all areas are densely built-up and impervious. On the contrary, the old Wilhelminian quarters – in this case north and south of the former Görlitz railway station – often feature rather generous greenery in private or semi-public areas, with very old trees in some areas. It emerges that, after 1918, open spaces became more important also in residential areas, at least in some parts of the inner city (cf. Figure 9).
This effect is even more pronounced in estates for which a “lose development interspersed with yards” was chosen as the construction style. Figure 10 illustrates this effect using two examples on the outskirts of the city centre, the “Neu-Tempelhof” estate and the row development with landscaped residential greenery south of “An der Wuhlheide” street in the borough of Treptow-Köpenick.
The chosen classification showcases the (height) structure in the parks such as the Großer Tiergarten, the green spaces of the Gleisdreieck or the Görlitzer railway station rather impressively. Area shares occupied by meadows may be easily distinguished from areas with higher vegetation types and those with trees. This applies similarly to forests and forest-like stands of trees.
Results of the change analysis
The total vegetation area in the entire urban area of Berlin amounted to 56,259 ha in 2020. This corresponds to 95.5 % of the total vegetation area of 58,907 ha that was still present in 2010 (cf. Table 2).
- Class 1: Vegetation not recorded in the initial analysis of 2009/ 2010, still present in 2020,
- Class 2: Vegetation present in 2010 and 2020,
- Class 3: Vegetation present in 2010, no vegetation in 2020,
- Class 4: Vegetation recorded in 2020, no vegetation in 2010,
- Class 5: Vegetation not recorded in the initial analysis of 2009/ 2010, no vegetation in 2020.
Overall, this means that the total area covered with vegetation in Berlin decreased by 2,648 ha between 2010 and 2020. This value represents both a loss of 3,574 ha (6.1%) of vegetation areas that were still present in 2010 and a gain of 926 ha (1.6%) of areas that were not yet vegetated in 2010. The total loss of vegetation areas that no longer exist corresponds to approximately 12 times the size of the Großer Tiergarten, i.e. a sizable area.
93.9 % of the area covered with vegetation in the reference year of 2010 remains a vegetation area in 2020. This corresponds to a vegetation area of 55,333 ha that remains unchanged.
The shares of specific vegetation height groups of the total vegetation area hardly changed between 2010 and 2020. Figure 11 shows the distribution for 2020. More than one third of the area is occupied by low-growing vegetation < 1 m.
Considering the change in the vegetation area share at the block (segment) area level, areas with increased construction activity and densification within blocks are clearly discernible (cf. Figure 12). These areas are distributed across the entire urban area.
Taking a look at the change in vegetation height at grid level (cf. Figure 13), it becomes apparent that forest areas, too, experienced considerable decreases in vegetation height. There does not seem to be a simple answer as to what caused this. Rather, it may be assumed that there were various influences at play at the same time. On the one hand, mature trees dying as a result of the dry summers may have been an influencing factor. On the other hand, consequences associated with human intervention, including the use of wood and the effects of the Mischwaldprogramm der Berliner Forsten (mixed forest programme of the Berlin Forests, only in German) to produce resistant forests with a large variety of species may have had a serious impact.