Optimising Dark Reserves for Biodiversity Conservation through Public Lighting Management

Public lighting has become a fundamental element of urban infrastructure, ensuring
safety, comfort, accessibility, and usability in public spaces such as streets,
parks, and public squares at night (1). However, artificial light at night (ALAN)
alters the natural light cycle, negatively impacting human health and biodiversity
(2; 3). While energy-efficient, the advent of light-emitting diode technology exacerbates
these biological responses due to its blue light emissions. To address this
issue, the nocturnal environment can be viewed as a social-ecological-technical
system (4). This lens could strategically support a balance between the ecological
and social components of nightscape management. This research aims to reconcile
these factors by minimising ALAN’s environmental impact while maintaining
critical social functions.
Among its many impacts, ALAN interferes with the movement and orientation
of species (3), which can generate significant population declines. Also,
ALAN interacts with other pressures, including habitat loss and fragmentation
(3). Strategies such as green corridors are deployed to support the movement of
diurnal species. Yet, ALAN may undermine them. Hence, tactical urban planning
decisions that consider activating and deactivating street lighting are needed
to create ecological linkages that respect nocturnal species.
Therefore, our research aims to answer the question: Which streetlights should
be turned off to create a dark corridor connecting core biodiversity areas and
forming a connected reserve?
Our research builds on Billionnet’s binary linear programming model for designing
connected and compact nature reserves (5). We adapt this model to
support the creation of dark corridors, incorporating novel constraints to minimise
artificial lighting and maintain areas of natural darkness. Our contributions
include a connectivity constraint to ensure the functional interconnection of dark
zones, the consideration of social acceptance of mitigation policies, and the introduction
of buffer zones to mitigate disturbances from urban settlements, roads,
1
and lighting.
The adapted model is tested on randomly generated instances. Future work
will apply the model to real-world data, refining its practical implementation to
support biodiversity conservation in urban and peri-urban environments.
References
[1] Tamar Trop, Sharon Shoshany Tavory, and Boris A. Portnov. Factors affecting
pedestrians’ perceptions of safety, comfort, and pleasantness induced
by public space lighting: A systematic literature review. Environment and
Behavior, 2023, 55(1-2), 3–46. doi:10.1177/00139165231163550.
[2] Ron Chepesiuk. Missing the dark: health effects of light pollution.
Environmental Health Perspectives, 2009, 117:A20–A27.
doi.org/10.1289/ehp.117-a20.
[3] Kevin Gaston, and Alejandro Sánchez de Miguel. Environmental impacts of
artificial light at night. Annual Review of Environment and Resources, 2022,
47:373–398. doi.org/10.1146/annurev-environ-112420-014438.
[4] Elodie Bebronne, Samedi Heng, and Sabine Limbourg. Towards sustainable
nocturnal environment management: a social-ecological-technical system
analysis in Wallonia (Belgium). Discover Environment, 2024, 2(1):98.
doi.org/10.1007/s44274-024-00128-z.
[5] Alain Billionnet. Designing connected and compact nature reserves.
Environmental Modeling and Assessment, 2016, 21:211–219.
doi.org/10.1007/s10666-015-9465-3.