A few years ago I was looking for a list of scientific journals that published commentary pieces (e.g., letters to the editor, essays, more policy-oriented pieces) for what would become Fox et al. 2015.  I couldn't find a comprehensive list, so I started one.  It's largely focused on conservation, ecology, environmental management, and sustainability science. Some articles are peer-reviewed while others aren't.

​I'll update it once in a while.  Please comment with a link (or email/DM me) if you know of other venues and article types. 
​

• Biodiversity and Conservation
  • ​Letter to Editor (<1000 words) on research articles published either in this journal or in other journals; can be controversial, need to cite supporting evidence for views expressed.
• Biological Conservation
  • Editorial: Opinion pieces by experts on a timely topic, usually invited by the Editor.
  • Perspective: Present a novel, distinctive viewpoint on any subject, grounded in evidence, thought-provoking (<8000 words)
  • Policy analysis: Contemporary, internationally relevant conservation or conservation-related policy issues that enable researchers, policy makers, and practitioners to make timely contributions to policy debates and actions (<4000 words)
  • Short communication: highlight novel research and/or replication studies with compelling preliminary findings relevant to conservation science/practice (<4000 words)
• Biotropica
  • Commentary (<2000 words): authoritative opinion on current issues in ecology or conservation, or thought-provoking commentary on previously published paper.
• Conservation Biology
  • ​Letters (<1000 words) regarding topics of immediate interest to readers, including on controversial subjects or papers previously published in the journal
• Conservation Letters
  • ​View Point (<1000 words), typically single-authored and invited by Editor-in-Chief, and aim to raise awareness and stimulate debate related to topical policy, practice and research relevant to conservation and human well-being.
  • Policy Perspectives (<3000 words) to discuss recent developments or ideas with broad and significant policy relevance to conservation
• Conservation Science & Practice
  • Perspectives and Notes (3000 words) to develop ideas with broad significance to conservation science, policy or practice
  • Evidence (1000 words) is related to the practice of conservation, including policy and planning
• Ecography
  • News & Views (<1500 words) are comments on recent exciting original research in Ecography or other relevant journals. 
• Facets
  • Editorial: <1400 words, no author limit, references and figures OK
  • Note: Reports completed project of smaller scope
  • Perspective: Fully referenced thought-piece discussing scientific concepts and proposing new ideas
  • Science Applications Forum: Link scientific knowledge to policy, management, public interests, industry applications
• Frontiers in Ecology and the Environment
  • ​Letters (Write Back): <800 words, max 10 authors, <15 references, one small figure or table
  • Guest editorial (~700 words), usually invited by the editor
• ICES Journal of Marine Science
  • ​​Food for Thought essays on topical,provocative, or innovative issues, solicited or offered to stimulate dialogue, research, and ideas
• Journal of Applied Ecology
  • Commentary: conceptual advance, opinion, or identifying gaps in knowledge
  • Policy Direction: improving and implementing decisions, management, policy
  • Practitioner’s Perspective: for practitioners to bridge research and the real world, make clear recommendations
• Marine Ecology Progress Series
  • ​As I See It: important, personal views on hot topics ("brief and fair", i.e., take your lengthy diatribe elsewhere) 
• Ocean and Coastal Management
  • ​Discussion papers (commentaries)
  • Correspondence (letters to the editors)
• Nature
  • ​Correspondence: <300 words, usually max 3 authors​
  • Comment: word limit not specified, 1-many authors, usually solicited by editors
  • Insights, Reviews, and Perspectives: Word limit not specified, 1-many authors
  • World View: ~900 words, single author, draw on personal experience and a call action
• Pacific Conservation Biology
  • ​News and correspondence (<1000 words) relevant to scientists at academic, research and non-governmental institutions; journal focuses on Australasia and Pacific
• PLOS Computational Biology
  • ​Ten Simple Rules: Papers provide quick, concentrated guide for mastering some of the professional challenges research scientists face in their careers.
• Proceedings of the National Academy of Sciences
  • Commentaries: invited by the editorial board
  • Front Matter (various types): invited by the editorial board. 
  • Perspectives: invited by the editorial board
  • [Anyone else think that's problematic? How does one get invited to this club?]
• Science
  • ​Letter to the editor: <300 words, seems to be about max 4 authors
  • Perspectives: <1000 words, 1 figure, 1-2 authors
  • Policy forum: 1000-2000 words, 1-2 figures, up to 15 references, 1-many authors 

Also, here's info about open-access fees in ecology, evolution, & conservation journals (not sure who made it).