|Nice, unharvested seeds.|
I am passionate about native plants. I’m quite serious- it has been years since I intentionally introduced a non-native plant to my yard (other than vegetables, of course). Naturally, I jumped at the chance to get involved when my work gave me the ‘go-ahead’ to help with native seed sourcing. However, seed collection is not so simple as “find, harvest, propagate”. Many native plants have suffered population declines from over-collection, so it is important to take steps to ensure an ethical harvest.
Ginseng, orchids, carnivorous plants, echinacea, black cohosh, golden seal, and galax have all suffered from over collection. What do these plants have in common? They are the medicinal, the rare, and the weird. This damage is nothing to be sniffed at. Galax is harvested for its value in floral arrangements. The majority of galax stands along the Blue Ridge Parkway in the Southern Appalachians were targeted by poachers in 2012 . Even worse, plants like ginseng, echinacea, and black cohosh are entirely destroyed by harvest, as the root is the part of the plant consumed. Others, like orchids and carnivorous plants, are delicate and often do not survive transplanting in their new environs anyway.
|Someone may have beat me to it. |
Or was it the wind?
Declines in medicinal plants have been well studied. Ginseng is a famous example. Recently, a ranking criterion was created to estimate the vulnerability of a plant to over collection. Traits on this list included: life history (i.e., how long does it take to reach maturity, what is its reproductive rate), effect of harvest (is the plant killed when harvested), population size, habitat, and demand . To avoid over collecting, one should limit the amount of seed collected from a population, and not collect from the same site year after year. There isn’t a consensus on exactly how much seed you can collect from a population without causing harm. Some sources say no more than a third, others say 10%, and others yet say 5% per year over 10 years. I am sure that the exact details of a ‘safe collection rate’ vary by species, population size, and location. Generally agreed upon exceptions to these guidelines are in the case of plant salvage—where plants are removed from a site prior to its destruction or development. In this case, 100% harvest is acceptable.
In addition to calibrating your harvest level against the possibility of causing real damage to the landscape, one must consider legality. Obviously it is illegal to collect protected species. It is also illegal to collect in most State and National Parks. Often one can collect on Forest Service or BLM land, but this typically comes with restrictions and requires the purchase of a permit for a small fee. Collecting on private land is OK with permission as long as the target plant is not protected. Roadsides are something of a toss-up—most seed collectors (including myself) believe road sides to be fair game. However, if someone requested that I stop collecting from along their property, I certainly would.
|Restored crop-field prairie|
Somehow, while juggling all these factors, I have managed to harvest from two sites. One was a roadway in Denton County. The other was a private prairie north of Temple. My harvest protocol in Denton was pretty clear-cut. Unless someone stopped me, I would be able to collect seed. Additionally, the roadsides had been mowed and most of the seed heads shattered, so I wasn’t too worried about over collecting. I probably couldn’t have collected more than 5% of the seed produced even if that had been my intent.
The second site, the private prairie, was a little fuzzier. While I made sure to get permission prior to collection, once I arrived on site it became clear to me that someone had already harvested some seeds from the target species earlier in the year. A few stalks had legible cut marks on them, while others did not. So the question became: how much could I take sustainably? How much seed had there been before the previous collector came?
After doing some looking around I decided that the original collectors had not taken much, and had collected from a central location along a mown path. Most of the bare stalks outside that area had a few seeds still hanging off them, suggesting that they had been shattered and scattered by non-human means. The plants that still held their seed were lower and had not been so exposed to the wind. I fretted some, and I never did settle on an exact amount that it would be OK to collect, but I did the best I could. I am comforted that, someday, the descendants of this foundation seed will be used for prairie restoration and will support many pollinators and other wildlife.
1. Castle, L. M., Leopold, S., Craft, R., & Kindscher, K. (2014). Ranking Tool Created for Medicinal Plants at Risk of Being Overharvested in the Wild. Ethnobiology Letters, 5, 77-88.