Cemeteries are critical to urban land management and environmental planning. They play crucial roles in wildlife management, stormwater management, plant diversity, urban heat island mitigation, and many other aspects of the environment of a city.
They influence populations of animals – pets and wildlife both, and people, too, for that matter. For wildlife, they can affect pests and also more desirable species (like migratory birds). They also affect population abundances of animals we might like – but might not want too much of (like deer). And they also can be and are used for walking dogs – and for walking people, as well.
What might be planted there – historic plants, rare plants, or perhaps even plants that may become weedy or invasive – influence the hydrology and the fauna, and also potentially the flora of surrounding areas. And lichens, which aren’t plants, but do photosynthesize, are commonly found on gravestones: http://www.gridphilly.com/grid-magazine/2013/10/30/grave-garden.html. Cemeteries can be refugia for lichens: https://bioone.org/journals/The-Journal-of-the-Torrey-Botanical-Society/volume-146/issue-1/TORREY-D-18-00029.1/First-Record-of-iUsnea-i-Parmeliaceae-Growing-in-New-York/10.3159/TORREY-D-18-00029.1.short (this was a discovery at Woodlawn Cemetery, in the Bronx).
Those plantings can and do affect temperatures – vegetation, or lack thereof, strongly influences urban heat island effects.
Separately or in sum, a city’s cemeteries have an intensive and extensive impact on the urban environment.
For example, over 1% of the land area of Philadelphia is cemeteries -this means that during a rainfall millions of gallons of water fall on cemeteries. And it translates into millions of plants, of hundreds of different species. And dozens upon dozens of migratory bird species.
The precise numbers of this impact are as-yet uncalculated, but even just with a bit of thinking about it, we can see it is quite large.
There are also, though, issues related to cemetery land management that one needs to be mindful of – ticks, mosquitoes, poison ivy – for example. Deer and other tick hosts may be attracted by food sources, and they may then bring those disease vectors with them. Also, crypts or mausoleums may provide appropriate hibernacula for overwintering mosquitoes (such as the common house mosquito – Culex pipiens). And, the open land management style can be conducive to extensive growth of poison ivy. Additionally, the use of embalming substances may affect the soils. These are all issues to be mindful of, given the cultural focus of cemeteries.
Cultural influences of surrounding communities around a cemetery, and also of the individuals whose loved ones are buried therein, provide a tremendous influence on what is planted and how, at any given cemetery. These cultural and historic overlays to planning and management are fundamental to the appropriate use of these sites, and therefore need to be fully integrated into planning.
And for cemeteries, culture, community and history are always richly intricate and critically important components: https://growinghistory.wordpress.com/category/cemeteries/
The complexity of cemetery land management is intensive and extensive, and this complexity provides both challenges and opportunities with regards to integrating these sites into local and regional scale planning, and the specific site management as well. Bringing it all together provides for long-range and long-term sustainability and broad positive impacts of cemeteries in urban areas.