Developing a Wilderness Quality Index for Continental Europe

Round 1

Reviewer 1 Report

This paper presents an updated wilderness quality map for Europe. It is based on an established and well documented methodology, which has been accurately applied by two experts in the field, and the paper is well written. Therefore, the manuscript is free from any major errors or concerns (though see point #2 below) and is suitable for publication following a minor revision to take into account the following comments and recommendations.

1.               While the wilderness quality index methodology is well established and documented, I recommend that the source publications should be cited by Rob Lesslie (deceased) who provided both the insight of assessing wilderness as a quality that can be measured across a continuum using a parametric approach based on indices of naturalness and remoteness, namely "Lesslie R.G. and Taylor S.G. (1985). The wilderness continuum concept and its implications for wilderness preservation policy. Biological Conservation, 32, pp. 309-33" and also the paper which documented the first computer-based application of this approach "Lesslie R.G. et al. (1988) A computer-based methodology for the survey of wilderness in Australia. Environmental Conservation 15, 225-232". 

2.              Page 3, line 97. I do have a concern regarding the “naturalness of land cover” values for forests. Commercial plantations, and all other forests that were not mapped as primary forests, were given a score of 9/10, with primary forests being given 10/10. I would have thought commercial plantations would be given a value of close to 0/10 and intensively managed (in particular, commercially logged) forests would be assigned something like 6/10. The authors need to justify why commercial plantations and intensively managed forests are assigned such a high value. Also, the authors should note that the Sabatini primary forest map is of modelled/predicted primary forest.

3.              I note that the authors have used the EU wilderness criterion that specifies a minimum size for core areas. Am I correct in assuming that wilderness areas equate with these "core areas"? Can the authors please just make that clear in the text. Also, some discussion is warranted on the point they note that the minimum core area threshold has been reduced from 3,000 to 2,000 ha. What is the reason for this? Is it political, socially/culturally or ecologically based? Do the authors have any comment about the benefits or limitations off applying such thresholds (using what is a continuous index) to delineate wilderness from non-wilderness areas?

Author Response

This paper presents an updated wilderness quality map for Europe. It is based on an established and well documented methodology, which has been accurately applied by two experts in the field, and the paper is well written. Therefore, the manuscript is free from any major errors or concerns (though see point #2 below) and is suitable for publication following a minor revision to take into account the following comments and recommendations.

Thank you, we will endeavour to address these as per below.

While the wilderness quality index methodology is well established and documented, I recommend that the source publications should be cited by Rob Lesslie (deceased) who provided both the insight of assessing wilderness as a quality that can be measured across a continuum using a parametric approach based on indices of naturalness and remoteness, namely "Lesslie R.G. and Taylor S.G. (1985). The wilderness continuum concept and its implications for wilderness preservation policy. Biological Conservation, 32, pp. 309-33" and also the paper which documented the first computer-based application of this approach "Lesslie R.G. et al. (1988) A computer-based methodology for the survey of wilderness in Australia. Environmental Conservation 15, 225-232". 

This is indeed an oversight. I knew Rob Lesslie and he was in many ways the main inspiration for my subsequent work on wilderness quality mapping. We have inserted a citation to Lesslie and Taylor (1985). Perhaps the best way of encapsulating this is to cite his final publication on this topic which summarises his contribution to the field, namely Lesslie R.G (2016). The wilderness continuum concept and its application in Australia: Lessons for modern conservation. In S.Carver and S.Fritz (eds) Mapping Wilderness: Concepts, Techniques and Applications, pp.17-33. Springer.

Page 3, line 97. I do have a concern regarding the “naturalness of land cover” values for forests. Commercial plantations, and all other forests that were not mapped as primary forests, were given a score of 9/10, with primary forests being given 10/10. I would have thought commercial plantations would be given a value of close to 0/10 and intensively managed (in particular, commercially logged) forests would be assigned something like 6/10. The authors need to justify why commercial plantations and intensively managed forests are assigned such a high value. Also, the authors should note that the Sabatini primary forest map is of modelled/predicted primary forest.

We have followed the approach in Kuiters et al (2013) here from the original EU Wilderness Register (and Index) report. There are a broad range of ‘managed’ forests from intensive, single non-native species (e.g. Sitka spruce) planted in rows and blocks with rotational clear felling/thinning, to continuous cover forestry with native species and selective felling/firewood collection. While the non-native commercial forestry operations could be given a lower weight, unified data on such operations across Europe or not available. This is better addressed in local level mapping. We have inserted a sentence in the paper to clarify this point.

I note that the authors have used the EU wilderness criterion that specifies a minimum size for core areas. Am I correct in assuming that wilderness areas equate with these "core areas"? Can the authors please just make that clear in the text. Also, some discussion is warranted on the point they note that the minimum core area threshold has been reduced from 3,000 to 2,000 ha. What is the reason for this? Is it political, socially/culturally or ecologically based? Do the authors have any comment about the benefits or limitations off applying such thresholds (using what is a continuous index) to delineate wilderness from non-wilderness areas?

This is a valid question, and the answer is quite political. For this reason, we have decided to remove reference to the variation in size criteria from this paper and focus on the WQI index/continuum itself. We have added some further reference to developing policy in Europe in the conclusions but feel the exploration of the specific criteria and mapping of possible future wilderness protected area boundaries is best done in a separate paper.

Reviewer 2 Report

The paper Developing a Wilderness Quality Index for Continental Europe presents a comprehensive update on previous data, offering valuable insights into the ongoing developments in the field. While the authors have effectively compiled and presented the updated information, the paper lacks originality and novelty of the work. Nevertheless the paper is well-organized, and the methodology is sound so I think it is worth of publication. 

The analysis utilizes up-to-date datasets to assess wilderness quality across the continent, providing valuable insights for developing a coordinated European policy on wilderness protection.  The methods are appropriate as they leverage advanced technology, incorporate updated datasets, utilize spatial analysis techniques. The results of the analysis on wilderness quality in Europe are relevant not only for understanding the current state of wilderness areas but also for guiding conservation policies, and informing future research and management efforts in the field of wilderness conservation and restoration.

Author Response

The paper Developing a Wilderness Quality Index for Continental Europe presents a comprehensive update on previous data, offering valuable insights into the ongoing developments in the field. While the authors have effectively compiled and presented the updated information, the paper lacks originality and novelty of the work. Nevertheless, the paper is well-organized, and the methodology is sound, so I think it is worth of publication. 

Thank you for comment. It is a good point regarding originality and novelty. The originality lies in making a much-needed extension and update of the original WQI to the non-EU European states and Russia west of the Urals, while the novelty lies in the use of GEE to achieve these aims. Comparison with global datasets in the form of the WCS Human Footprint Index and discussion around scale/resolution of source data adds further novelty that will be hugely relevant in taking the work forward.

The analysis utilizes up-to-date datasets to assess wilderness quality across the continent, providing valuable insights for developing a coordinated European policy on wilderness protection.  The methods are appropriate as they leverage advanced technology, incorporate updated datasets, utilize spatial analysis techniques. The results of the analysis on wilderness quality in Europe are relevant not only for understanding the current state of wilderness areas but also for guiding conservation policies and informing future research and management efforts in the field of wilderness conservation and restoration.

Thank you.

Reviewer 3 Report

Dear authors,

The update and extent of the wilderness quality index is an extraordinary effort. I hope this research supports better decisions. This research will assist in making better decisions regarding priority areas for conservation. My main suggestion is to relocate the paragraph regarding the potential uses of WQI 2.0 (line 309) to the discussion section and provide additional support for the recommendation.

Author Response

The update and extent of the wilderness quality index is an extraordinary effort. I hope this research supports better decisions. This research will assist in making better decisions regarding priority areas for conservation. My main suggestion is to relocate the paragraph regarding the potential uses of WQI 2.0 (line 309) to the discussion section and provide additional support for the recommendation.

Thank you, this is a useful suggestion. We have moved this paragraph to the discussion and inserted a short section in the conclusions to reiterate the utility of the WQI 2.0 in decision-making around the 30x30 targets.

Reviewer 4 Report

In its current form, the paper's potential is not fully shown. 

Below there are some specific comments:

Abstract - around line 17 the main conclusions considering discovered differences between old and new indexes or just tendences should be added. 

In the introduction section, however, there is a need to explain why wildness is important - in different contexts of the functioning of the modern world There is numerouse literature on this subject.

Line 207 please describe what categories 1a, 1b etc mean.

Fig 4 - descriptions are not readable.

Table 3 - could be nice and usefull to now how about rest of countries.

Line 226 and below - maps 5 - 8 need to be described beforehand - it is not clear what is the result - what is important. The Authors should present description of the results with the differences - maybe numerically?

Generally in the Results section the differences should be better described - please give characteristic numbers.

Many more isisuess should be raised in the discussion - greater distance is beneficial for wildness but wildness provides the highest level of ecosystem services for people - how to reconcile this ? its possible?

In conclusion section large parts need to be moved to discussion and expanded - lines 302-308, lines 312 - 324

After these corrections and additions, the conclusions will still need to be improved

Author Response

In its current form, the paper's potential is not fully shown. 
Below there are some specific comments:

Abstract - around line 17 the main conclusions considering discovered differences between old and new indexes or just tendences should be added. 

We have added a sentence on main differences between WQI 1.0 and WQI 2.0 as requested.

In the introduction section, however, there is a need to explain why wildness is important - in different contexts of the functioning of the modern world There is numerous literature on this subject.

We have inserted a new paragraph at the beginning of the introduction section briefly outlining why we consider wilderness and its protection to be important, citing relevant policy and literature.

Line 207 please describe what categories 1a, 1b etc mean.

We have inserted descriptions of these IUCN categories into this sentence.

Fig 4 - descriptions are not readable.

We have increased the size of the images and text in this figure.

Table 3 - could be nice and useful to know how about rest of countries.

We have changed Table 3 to be a ranking of countries by proportion of their territory with high wilderness index and included all countries in this study.

Line 226 and below - maps 5 - 8 need to be described beforehand - it is not clear what is the result - what is important. The Authors should present description of the results with the differences - maybe numerically?

We have inserted a sentence in the text explaining these figures prior to their introduction in the paper and provided some summary data.

Generally, in the Results section the differences should be better described - please give characteristic numbers.

Thank you, this is dealt with in the preceding response.

Many more issues should be raised in the discussion - greater distance is beneficial for wildness but wildness provides the highest level of ecosystem services for people - how to reconcile this ? its possible?

Thank you. If we understand your point correctly, you are suggesting that delivery of ecosystem service benefits from wilderness areas to human populations is dependent on distance, i.e. nearer wilderness areas (‘urban proximate’) will deliver greater ecosystem service value than wilderness areas that are more remote from human populations. This very much depends on what service and its delivery mechanism as per Fisher et al. (2009) Defining and classifying ecosystem services for decision making. Ecological Economics, 68, 643-653. We have included a sentence clarifying this point in the text.

In conclusion section large parts need to be moved to discussion and expanded - lines 302-308, lines 312 – 324.

See above.

After these corrections and additions, the conclusions will still need to be improved.

See above.

Round 2

Reviewer 4 Report

Im satisfied with improvements Thank to the Editors for a pleasure of reviewing the paper.

Author Response

Thanks for the positive response. We've made changes to the text and citations and upload here. Again, thanks for your time and expertise.