Ecology

Evaluation Summary:

This paper will be of interest to urban foresters, ecologists, and planners. It provides an urban tree dataset across US cities that can be used to address questions on urban biodiversity and ecosystem services. It contains clear descriptions about the data processing and structures in general, but would need further clarifications about the sample completeness and representativeness of the data.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. The reviewers remained anonymous to the authors.)

Evaluation Summary:

This paper is of potential interest to people working at the interface between agronomy, ecology, and evolution. By growing experimental mixtures of crop species, i.e., intercrops, the study aims at testing whether positive interactions between species grown in association strengthen over generations of coexistence. The data are original and of high quality, and the statistical analysis are rigorous. The interpretation of the Results as well as the Discussion and Conclusions currently ignore an important discrepancy in the results for competition versus overall yield.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #3 agreed to share their name with the authors.)

Evaluation Summary:

Kruse and Herzschuh apply LAVESI, a machine-intensive and spatially-explicit simulation of individual Siberian trees at the tundra-forest boundary, to call attention to the rapid reduction in the tundra biome as climate warming pushes forests toward the Arctic Ocean. This detailed modelling study predicts dramatic losses of tundra area by the middle of the millenium even under an ambitious climate mitigation scenario and highlights considerable risks of extinction.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 agreed to share their name with the authors.)

Evaluation Summary:

This study will be of interest to wildlife ecologists and conservation practitioners. The authors took a collaborative approach and collated a large dataset of wildlife camera trap recordings across cities in the USA. The analyses reveal variability in diel activity among species and cities, providing important insights into the effects of urbanization.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 and Reviewer #2 agreed to share their name with the authors.)

Evaluation Summary:

Hoverflies are a group of insects that provide crucial ecosystem services such as pollination and crop protection. Their migratory behavior in western countries is well characterized, but in eastern Asia, the annual summer monsoon provides a 'highway' of favorable winds for the airborne transport of migratory organisms, and the migration of hoverflies in this large region has not been well studied. This study addresses hoverfly migration in this region and its consequences using a variety of suitable methods. The work will be of great interest to insect migration biologists and pollination ecologists.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1, Reviewer #2 and Reviewer #3 agreed to share their name with the authors.)

Evaluation Summary:

The manuscript reports that when lowland plants were transplanted into alpine turfs under lowland climatic conditions, they rapidly increase soil microbial decomposition of carbon stocks due to root exudates feeding the microbes. The authors conclude that when lowland plants migrate to alpine sites and these warm up, they may also cause a pulse of carbon loss from soil. An alternative explanation of their findings might be that when alpine plants are transplanted into alpine turfs under lowland climatic conditions, these are unable to increase soil microbial decomposition as much as lowland plants because the latter are better adapted to their climatic home environment.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 and Reviewer #4 agreed to share their names with the authors.)

Evaluation Summary:

Manipulations of sex hormones in animals in ecologically relevant environments usually involve long-term manipulations using chronic implants or injections of esterified steroids with longer half-lives than the endogenous hormones. This has been done in line with the prevailing idea of the long-lasting effects of steroids mediated by the transcritpional actions of their liganded receptors. The specific novelty of this study lies in the transiency of hormone availability (testosterone's half-life is about 2 hours). This might suggest that the observed effects depend on a mode of action different from the mode of action during chronic sex hormone exposure. It should also be noted that any study in natural settings is significantly more difficult to perform than in the lab. However, as all brain/hormonal functions evolved in natural environments, these studies are absolutely crucial to understand the function of the respective systems.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. The reviewers remained anonymous to the authors.)

Evaluation Summary:

Urbanization has broad impacts for macroecology but its consequences for wildlife microbial ecology remain unclear. Dillard et al. hypothesize that humans living in an urban setting may transfer their microbes to wildlife with potential adverse effects. They analyze 16S rRNA gene sequencing data from humans, crested anoles, and coyotes, leading to the discovery of multiple bacteria that fit the pattern of urbanization and inter-species transfer.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1, Reviewer #2 and Reviewer #3 agreed to share their name with the authors.)

Evaluation Summary:

Zhou et al. provide a robust study on isotopic and metabolic changes of a soil community across a gradient of different land-use types in Sumatra, Indonesia. By mixing community-based analyses of stable isotopes and size-based metabolic measures, they are able to elucidate, for the first time, important links among plants and the soil food web in tropical ecosystems. This study is of importance to tropical biologists, ecosystem ecologists and biodiversity conservationists aiming to understand the impacts of humans on tropical forests.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. The reviewers remained anonymous to the authors.)

Evaluation Summary:

Wang et al. adapt a new statistical framework for a multi-site multi-year data set to investigate the effects of environmental variables on the temporal stability of plant communities and biomass productivity in Chinese grassland communities. This new framework may well turn out to be one that the larger ecological and ecosystem academic communities, interested in temporal changes of ecological processes across large spatial scales, have been looking for.

(This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. The reviewers remained anonymous to the authors.)