In a natural burial grounds, it is common to include native vegetation at the burial site. Flowers, boughs, and other greenery can be used to line the bottom of the grave and add beauty to the natural setting. While these techniques may be comforting for the participants, it's not that we are trying to hide the dirt (like the plastic grass mats at conventional cemeteries)! It's just the opposite- we encourage the loved ones to take part in the burial service, including shoveling the dirt if desired. But having flowers and other elements of nature to beautify the grave site is an ancient element of funeral ritual, and it can be reassuring to be reminded of nature's cycles during these solemn moments.
Adding vegetation to the grave site also helps the soil ecology in a variety of ways. Any spores or microorganisms present on the plants will be introduced to area. This can help kickstart the fungal processes that help create healthy soil. The moisture within the tissues of the plants help nourish this process, too. For burial in the Preserve, we use whatever plants are abundant and seasonal at the time of the burial service. In the depth of winter if nothing green is available, we will use a bale of straw to line the grave for this same purpose.
The other benefit from vegetation in the grave is that the texture helps add void areas in the soil where oxygen is present. These air pockets also help with the microbial processes we want to encourage in a burial site. Then, as the plant matter ultimately decays, pores and channels develop in the soil in their place. These spaces, especially when they fill with ground water, are amazing microcosm habitats for soil microbes. Resilient, carbon-sequestering soil is dependent on two things- a diversity of sizes of pores like these, and remaining undisturbed. So, we include organic matter as we close the grave, and then provide conservation protections to the area, to give the Earth the best possible conditions for returning our remains to the soil.