Lines 376-378: I don't see the direct link between homogenization and equality of change among losers and winners. Either prove/show the link mathematically, or drop the statement.Probably, this disagreement is based on how we define homogeneity. In our opinion, homogenization is the direct consequence of redistribution of the species' cover. If decreases are distributed more equally (that is also more homogeneously) across many species and increases in cover are concentrated in few species, the latter (that is the winners) will be increasing in many communities. In consequence, the dissimilarity in species composition between these communities has to decrease (given that a quantitative dissimilarity measure is used). Mathematically, this would have to be shown by a decrease in dissimilarity, which however, is difficult to demonstrate across all plot records in our data set as many communities have no species in common. In our opinion, homogenization probably occurs within habitat types, but opening this discussion and carrying out the analysis would open a can of worms. Thus, we have decided to down-tune this statement to: "Homogenisation occurs because, across all time series, few species consistently increase in their cover, meaning that the same species are winning in many communities." (new l 372-374)Referee #3 (Remarks to the Author):As before, I commend the authors on their analyses and believe this paper makes a novel and important contribution by documenting long-term plant biodiversity changes in terms of cover that would have been missed by simply focusing on species richness, as most previous work has done. But while the authors have produced a strong revision of their paper, in my opinion several outstanding issues remain, and some important comments have only been partially addressed. I appreciate the new analyses that the authors have performed, and overall the analyses are appropriate and justified, and data are presented correctly, as far as I can judge. The framing of the study is also now more compelling, and I think the unique value of the dataset and insights arising from it are now harnessed more effectively. That said, I still have some concerns about the framing of the study, explained in my comments below. The Results section has also been improved, but remains difficult to read in places -again, I make specific suggestions below. Overall, while the length appears to have been reduced, the text still seems unnecessarily wordy in places (e.g. in the Results and figure captions).Thank you for this positive assessment.Another aspect I raised previously and has still not been resolved, in my opinion, is when results are considered to be ecologically relevant or not, and I think there could be greater transparency in the paper about this. This relates to the way the story is set-up, as mentioned in my previous review. Specifically, the authors note that due to the large sample sizes, changes in species richness can be statistically significant even if effect sizes are small, and therefore conc...

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Vegetation-plot resurvey data are a main source of information on terrestrial biodiversity change, with records reaching back more than one century. Although more and more data from re-sampled plots have been published, there is not yet a comprehensive open-access dataset available for analysis. Here, we compiled and harmonised vegetation-plot resurvey data from Germany covering almost 100 years. We show the distribution of the plot data in space, time and across habitat types of the European Nature Information System (EUNIS). In addition, we include metadata on geographic location, plot size and vegetation structure. The data allow temporal biodiversity change to be assessed at the community scale, reaching back further into the past than most comparable data yet available. They also enable tracking changes in the incidence and distribution of individual species across Germany. In summary, the data come at a level of detail that holds promise for broadening our understanding of the mechanisms and drivers behind plant diversity change over the last century.

Semi‐natural mountain grasslands are increasingly exposed to environmental stress under climate change. However, which are the environmental factors that limit plants in these grasslands? Also, is the present management effective against these changes? Fitness‐related functional traits may offer a way to detect changes in performance and provide new insights into their vulnerability to climate change. We investigated changes in performance and variability of functional traits of the mountain grassland target species Arnica montana along a climate gradient in Central German low mountain ranges. This gradient represents at its lower end climate conditions that are expected at its upper end under future climate change. We measured vegetative, generative, and physiological traits to account for multiple ways of plant responses to the environment. Using mixed effects and multivariate models, we evaluated changes in trait values among individuals as well as the variability of their populations in order to assess performance under changing summer aridity and different management regimes. Fitness‐related performance of most traits showed strongly positive associations with reduced summer aridity at higher elevations, while only specific leaf area and leaf dry matter content showed no association. This suggests a higher performance level at less arid montane sites and that the physiological traits are less sensitive to this climate change factor. The coefficient of variation of almost all traits declined steadily with decreasing site aridity. We suggest that this reduced variability indicates a lower environmental stress level for A. montana toward its environmental optimum at montane elevations, especially because the trait performance increased simultaneously. Surprisingly, management factors and habitat characteristics had only low influence on both trait performance and variability. In summary, summer aridity had a stronger effect to shape the trait performance and variability of A. montana under increased environmental stress than management and other habitat characteristics.

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