Legal cannabis cultivation in Colorado caused habitat encroachment into threatened species areas

Geospatial analysis found that licensed cannabis cultivation in Colorado caused over 67 hectares of land use change, new fencing, and vegetation clearing in areas harboring threatened and endangered species.

Klassen, Mark et al.·Environmental management·2022·Moderate EvidenceObservational
RTHC-03969ObservationalModerate Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Observational
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

From 2011 to 2016, licensed cannabis cultivation resulted in over 67 hectares of land use change toward more developed uses. Nearly 15 km of new fencing was constructed establishing over 38 hectares of fenced areas, and nearly 60 hectares of vegetation was cleared. Much of this change occurred within habitats of threatened and endangered species.

Key Numbers

67+ hectares of LULC change. 15 km of new fencing. 38+ hectares fenced. ~60 hectares vegetation cleared. Changes primarily from outdoor and greenhouse facilities in rural areas.

How They Did This

Geospatial analysis of licensed recreational cannabis cultivator locations in Colorado. Examined distribution of cultivators, potential habitat infringement of threatened and endangered species, and land use/land cover (LULC) change from 2011 to 2016.

Why This Research Matters

Legalization is often framed as environmentally beneficial by moving cultivation indoors and under regulation. This study shows that legal outdoor and greenhouse cultivation can still cause significant habitat encroachment.

The Bigger Picture

Cannabis legalization creates a new agricultural industry competing for land. Without policies specifically directing cultivation to urban indoor facilities, habitat loss may be an unintended consequence of liberalized cannabis laws.

What This Study Doesn't Tell Us

Single state (Colorado). LULC analysis may not capture all environmental impacts. 2011-2016 timeframe may not reflect current patterns. Cannot determine species-level impacts from habitat proximity alone.

Questions This Raises

  • ?Would mandating indoor urban cultivation prevent habitat encroachment?
  • ?How do environmental impacts of legal cannabis compare to other new agricultural crops?

Trust & Context

Key Stat:
67+ hectares of habitat change; threatened species areas affected
Evidence Grade:
Detailed geospatial analysis with specific land use measurements, but single state and limited timeframe.
Study Age:
Published in 2022, covering 2011-2016.
Original Title:
Legalization of Cannabis and Agricultural Frontier Expansion.
Published In:
Environmental management, 69(2), 333-352 (2022)
Database ID:
RTHC-03969

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Watches what happens naturally without intervening.

What do these levels mean? →

Frequently Asked Questions

Does legal cannabis farming harm the environment?

In Colorado, licensed cannabis cultivation caused over 67 hectares of land use change, including vegetation clearing and fencing in areas that overlap with threatened and endangered species habitats.

Can cannabis legalization be environmentally friendly?

This study suggests policies should encourage indoor urban cultivation rather than rural outdoor or greenhouse operations, which were the primary drivers of habitat encroachment.

Read More on RethinkTHC

Cite This Study

RTHC-03969·https://rethinkthc.com/research/RTHC-03969

APA

Klassen, Mark; Anthony, Brandon P. (2022). Legalization of Cannabis and Agricultural Frontier Expansion.. Environmental management, 69(2), 333-352. https://doi.org/10.1007/s00267-021-01555-x

MLA

Klassen, Mark, et al. "Legalization of Cannabis and Agricultural Frontier Expansion.." Environmental management, 2022. https://doi.org/10.1007/s00267-021-01555-x

RethinkTHC

RethinkTHC Research Database. "Legalization of Cannabis and Agricultural Frontier Expansion..." RTHC-03969. Retrieved from https://rethinkthc.com/research/klassen-2022-legalization-of-cannabis-and

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.