Legalization of Cannabis and Agricultural Frontier Expansion

Abstract

The environmental impacts of cannabis cultivation have been an issue of growing concern, with legalization often framed as a means to introduce regulations that hinder damaging practices. However, the concept of frontier expansion presents the possibility that the widespread establishment of this new industry may institute an additional source of habitat encroachment. Here, through geospatial analysis, we employ Colorado as a case study to investigate the distribution of licensed recreational cannabis cultivators, potential habitat infringement of threatened and endangered species, and LULC change. From 2011 to 2016, licensed cannabis cultivation has resulted in over 67 ha of LULC change toward more developed land uses. In addition, nearly 15 km of new fencing was constructed establishing over 38 ha of fenced areas, and nearly 60 ha of vegetation was cleared. Much of this cannabis-driven LULC change is identified within the habitats of threatened and endangered species, as well as areas recognized as containing high biodiversity values with the potential for conservation. Thus, notable cannabis-driven frontier expansion is evident. Cannabis-driven LULC change is found to be primarily produced by outdoor and greenhouse facilities, as well as operations utilizing mixed-cultivation methods in rural areas. Therefore, policy instruments that inter alia encourage indoor cannabis cultivation in urban areas are recommended and discussed.

Appendices

Appendix 1

National land cover database legend

Class	Classification description
Open water	Areas of open water, generally with less than 25% cover of vegetation or soil
Perennial ice/snow	Areas characterized by a perennial cover of ice and/or snow, generally greater than 25% of total cover.
Developed, open space	Areas with a mixture of some constructed materials, but mostly vegetation in the form of lawn grasses. Impervious surfaces account for less than 20% of total cover. These areas most commonly include large-lot single family housing units, parks, golf courses, and vegetation planted in developed setting for recreation, erosion control, or esthetic purposes.
Developed, low intensity	Areas with a mixture of constructed materials and vegetation. Impervious surfaces account for 20% to 49% percent of total cover. These areas most commonly include single-family housing units.
Developed, medium intensity	Areas with a mixture of constructed materials and vegetation. Impervious surfaces account for 50% to 79% of the total cover. These areas most commonly include single-family housing units.
Developed, high intensity	Highly developed areas where people reside or work in high numbers. Examples include apartment complexes, row houses and commercial/industrial. Impervious surfaces account for 80% to 100% of the total cover.
Barren land (rock/sand/clay)	Areas of bedrock, desert pavement, scarps, talus, slides, volcanic material, glacial debris, sand dunes, strip mines, gravel pits and other accumulations of earthen material. Generally, vegetation accounts for less than 15% of total cover.
Deciduous forest	Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75% of the tree species shed foliage simultaneously in response to seasonal change.
Evergreen forest	Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75% of the tree species maintain their leaves all year. Canopy is never without green foliage.
Mixed forest	Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. Neither deciduous nor evergreen species are greater than 75% of total tree cover.
Dwarf scrub	Alaska only areas dominated by shrubs less than 20 centimeters tall with shrub canopy typically greater than 20% of total vegetation. This type is often coassociated with grasses, sedges, herbs, and nonvascular vegetation.
Shrub/scrub	Areas dominated by shrubs; less than 5 meters tall with shrub canopy typically greater than 20% of total vegetation. This class includes true shrubs, young trees in an early successional stage or trees stunted from environmental conditions.
Grassland/herbaceous	Areas dominated by gramanoid or herbaceous vegetation, generally greater than 80% of total vegetation. These areas are not subject to intensive management such as tilling, but can be utilized for grazing.
Sedge/herbaceous	Alaska only areas dominated by sedges and forbs, generally greater than 80% of total vegetation. This type can occur with significant other grasses or other grass like plants, and includes sedge tundra, and sedge tussock tundra.
Lichens	Alaska only areas dominated by fruticose or foliose lichens generally greater than 80% of total vegetation.
Moss	Alaska only areas dominated by mosses, generally greater than 80% of total vegetation.
Pasture/hay	Areas of grasses, legumes, or grass-legume mixtures planted for livestock grazing or the production of seed or hay crops, typically on a perennial cycle. Pasture/hay vegetation accounts for greater than 20% of total vegetation.
Cultivated crops	Areas used for the production of annual crops, such as corn, soybeans, vegetables, tobacco, and cotton, and also perennial woody crops such as orchards and vineyards. Crop vegetation accounts for greater than 20% of total vegetation. This class also includes land being actively tilled.
Woody wetlands	Areas where forest or shrubland vegetation accounts for greater than 20% of vegetative cover and the soil or substrate is periodically saturated with or covered with water.
Emergent herbaceous wetlands	Areas where perennial herbaceous vegetation accounts for greater than 80% of vegetative cover and soil or substrate is periodically saturated with or covered with water.

Source: USGS, 2021

Appendix 2

Licensed recreational cannabis cultivators and threatened/endangered amphibian species’ habitats or related proxy variables in Colorado (2016). Sources: CPW, 2020; Natural Earth 2021..

Appendix 3

Licensed recreational cannabis cultivators and threatened/endangered bird species’ habitats or related proxy variables in Colorado (2016). Sources: CPW, 2020; Natural Earth 2021. .

Appendix 4

Licensed recreational cannabis cultivators and threatened/endangered mammal species’ habitats or related proxy variables in Colorado (2016). Sources: CPW, 2020; Natural Earth 2021. .

Appendix 5

Licensed recreational cannabis cultivators and threatened/endangered reptile species’ habitats or related proxy variables in Colorado (2016). Sources: CPW, 2020; Natural Earth 2021. .