Correction: Coleman, K.; Kuenzer, C. Forest Fragmentation in Bavaria: A First-Time Quantitative Analysis Based on Earth Observation Data. Remote Sens. 2025, 17, 2558

Text Correction

There were several errors in the original publication [1]. A sign inversion in the calculation of aspect caused the orientation of the results to also become inverted. The data was re-calculated.

A correction has been made to the Abstract:

Anthropogenic and climatic pressures can transform contiguous forests into smaller, less connected fragments. Forest biodiversity and ecosystem functioning can furthermore be compromised or enhanced. We present a descriptive analysis of forest fragmentation in Bavaria, the largest federal state in Germany. We calculated 22 metrics of fragmentation using forest polygons, aggregated within administrative units and with respect to both elevation and aspect orientation. Using a forest mask from September 2024, we found 2.384 million hectares of forest across Bavaria, distributed amongst 83,253 forest polygons 0.1 hectare and larger. The smallest patch category (XS, <25 ha) outnumbered all other size classes by nearly 13 to 1. Edge zones accounted for more than 1.68 million hectares, leaving less than 703,000 hectares as core forest. Although north-facing slopes dominated the state, the highest forest cover (~36%) was found on the least abundant west-oriented slopes. Most of the area is located at 400–600 m.a.s.l., with around 30% of this area covered by forests; however, XL forest patches (>3594 ha) dominated higher elevations, covering 30–60% of land surface area between 600 and 1400 m.a.s.l. The distribution of the largest patches follows the higher terrain and corresponds well to protected areas. K-Means clustering delineated three clusters, which corresponded well with the predominance of patchiness, aggregation, and edginess within districts.

A correction has been made to the Results, paragraphs 4 and 5:

Figure 8B,C summarizes the distribution of patches with regard to terrain. In Figure 8B, above 2000 m, there is no forest cover; this information is therefore omitted from this figure. The total area of each elevational zone is represented on the right y-axis, with bars outlined in purple (1 × 10⁶ ha). The 1000–1200 m elevational zone contains the highest percent of forest cover, at just over 60%; however, this zone is among the smallest, covering about 120,000 ha. The lowest elevational zone, 0–200 m, is covered by less forest than each subsequent zone until the climatic conditions limit tree growth above 1400 m. The smallest forest patches are relatively evenly distributed across the elevational zones compared to L and XL patches, which make up the largest share of forest coverage as elevation increases. Most of the land surface area of the state falls within the 400–600 m elevation zone (about 3.75 million ha); however, only about 30% is covered by forested area.

The total area is not evenly distributed amongst the four aspect directions (Figure 8C). The majority of slopes are north-facing and have the second highest percent forest cover. The smallest slope category was west; however, these slopes had the highest percent coverage of forest. East-facing slopes had the smallest forest coverage overall.

A correction has been made to the Discussion, 4.4. Terrain Distribution, paragraphs 1 and 2:

In this investigation, we included a brief description of topographical patterns of forested areas. Elevation varies across the state with most of the land surface located below 600 m.a.s.l.; however, the largest forests are primarily located at elevations above this and are predominantly west-oriented, although western slopes cover less total area than other aspects. Management and forest ownership often determine the location of forests; however, topography affects microclimatic conditions, which can play a role in the resilience or severity of disturbance effects.

Temperature and precipitation vary with elevation and are thus limiting growth factors, especially in mountainous terrain; meanwhile, sunlight is influenced by aspect orientation. Topographically modulated microclimates can have an effect on tree height, aboveground biomass, basal area, and species distribution [84]. Elevation, aspect, and slope (not investigated in this study) interactively effect tree growth, whereby the optimal orientation is determined by elevation [85]. With respect to disturbances, the magnitude of the forest loss can depend on elevation and slope orientation [86,87]. West-facing forest patches in Bavaria may experience microclimatic advantages over other orientations, especially south- and east-facing patches. Although eastern slopes could experience less frost due to morning sunlight whilst avoiding direct afternoon sun exposure (thereby reducing evaporative demand), west-facing slopes may be warmer overall due to late afternoon sun exposure at the highest temperature point in the day. These conditions would also have an effect on soil moisture, which furthermore supports forest growth. It may also be possible that forest loss during recent years has had a disproportionate effect based on aspect orientation, resulting in the higher proportion of forest cover on west-facing slopes. A follow-on investigation will address this gap using time-series forest loss data.

A correction has been made to the Conclusions, paragraph 2:

Although more than a third of the land surface of the state is covered by forests, the results suggest that the forest landscape of Bavaria is dominated by fragmentation per se, given that the smallest patches (<25 ha) outnumber all other patch sizes. The number of small patches together with the amount of edge zone and perimeter length relative to the core area also suggests that edge effects dominate the smallest patches, which contain no core area. The largest forests are distributed at the highest elevations and are predominantly west-facing, a phenomenon that warrants further investigation.

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Error in Figure and Legend

In the original publication, there was a mistake in Figure 8C as published. A sign inversion in the calculation of aspect caused the orientation of the results also to become inverted. The data was re-calculated and the figure has been updated. The corrected Figure 8C and Figure Legend appears below.

Figure 8. An overview of forest patch size and distribution (A). Elevations of less than 600 m.a.s.l comprise the majority of the area in the state; however, forest cover is highest at elevations between 800 and 1400 m.a.s.l. (B). Most hillsides are oriented to the north; however, west-facing slopes account for the greatest amount of forest cover (C).

Figure 8. An overview of forest patch size and distribution (A). Elevations of less than 600 m.a.s.l comprise the majority of the area in the state; however, forest cover is highest at elevations between 800 and 1400 m.a.s.l. (B). Most hillsides are oriented to the north; however, west-facing slopes account for the greatest amount of forest cover (C).

The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated.