The Decline of Lemon Lilies in the Idyllwild Area
Table of Contents
Introduction
What caused the decimation of this population?
Why haven't lemon lilies come back to the Idyllwild Area in their former density?
Plans for Restoration of the population
Lemon Lily Festival Dates
Introduction Lemon lilies were once so abundant at San Jacinto Mountain that in 1902, Harvey Monroe Hall wrote, in his botanical flora of the Pine Belt of San Jacinto Mountain:
It was only a few years ago that the showy blossoms were very frequently met with along all the streams and bogs from nearly the lower edge of [the Pine Belt] up to an altitude of 9000 feet.But in just a few years, the lemon lilies became so infrequent that Hall wrote you had to go to more remote parts of the mountain to see them in profusion.
That rarity has continued to today, 114 years later. On most trails in the Idyllwild area (here defined as being the lower pine belt from the Black Mountain area to the Mountain Center area), one meets with no lemon lilies at all, or at best a handful.
What caused the decimation of this population? A number of factors are in play, but by far the dominant factor was people collecting bulbs to be sold to gardeners. Hall wrote one party took out over 5000 bulbs in a single season. The bulb collectors probably dug up every single lily they could find, leaving the areas bereft of lemon lilies wherever the collectors went.
For a number of species, this might not have been fatal, and they could have recovered from such a decimation of their population. But several characteristics of lemon lilies made it very hard for them to recover from such a blow:
- Lemon lilies are not self-fertile. To produce seeds requires a pollinator to travel with pollen from another flower. If flowering lemon lilies suddenly become spaced too far apart for a pollinator to travel between them, they will no longer produce seeds.
- Lemon lilies do not in general reproduce vegetatively. Very old plants can sometimes produce two stalks from growth of the original bulb into two bulbs, but they remain intimately connected. We have never seen a clump of lemon lilies that might have come from vegetative propagation.
- There is no significant seed bank that could have restored the population. Although the seeds themselves can survive for many years if stored in good conditions, seeds in nature probably do not last more than one or two years. The seeds are either eaten by a predator, germinate in their first year, or are washed downstream to unsuitable habitat.
- Lemon lily plants are slow-growing, taking something like three to five years before they produce their first flower. They are especially vulnerable when young, producing just a single small leaf in their first year. Damage to that leaf may kill the young plant.
- Even though plants that produce fruit produce hundreds to thousands of seeds each year for the lifetime of the flowering / fruiting plant, on average just one of those seeds is able to produce a plant that itself produces seeds. This has to be the case for all plant species whose population is not expanding or contracting, and simply reflects the long odds that an individual seed will produce a plant that reproduces. Even if the seed escapes predators such as birds and rodents, and ends up in suitable habitat for germination, the baby plant may not grow where the plants can be protected from gophers, who love to eat lemon lily plants, and where the water requirements of the adult plant are met.
- Lemon lilies face a number of threats to their survival in the wild. The two main predators of the lilies are gophers which devour the bulbs and kill the entire plant; and deer that relish the flower buds. Habitat challenges include water fluctuations, bulb rot, erosion and sedimentation.
The effect of predation was magnified when the population was vastly decreased by the bulb collectors. If gophers killed 10% of the original population each year, that was not a major threat to the population. However, if 90% of the population was removed by bulb collectors, and gophers continued to eat the same number of bulbs, they would try to consume the entire population left by bulb collectors each year. Of course, as lemon lilies became scarce, the gophers would not be able to consume as many plants as they formerly did, but would still be a much-bigger threat to the population than they were formerly.
- Many people like to pick the flowers. While this is not imminently fatal to an individual plant, if all the flowers are removed before they are pollinated and can set seed then there will be no recruitment of young plants, and the population will collapse. Some years ago, Dave witnessed a hiker carrying a bouquet of lemon lily flowers down the Devils Slide Trail, in order to cheer up a person who could no longer hike to see them. That person obviously had no idea of the potential harm he was causing to the population.
- The plants are quite delicate throughout their growth cycle and are easily trampled. We have witnessed such trampling repeatedly for another lily, the chocolate lily at the Santa Rosa Plateau, where photographers trample many plants which have not yet bloomed in order to get the "perfect" picture of the first one in bloom. The same trampling surely happens for lemon lilies.
Removing the bulbs of every lily that can be found in an area is therefore a recipe for extirpating the population in that area, as all these characteristics conspire to make it difficult for the population to recover.
Hall also wrote that there, that there were several consecutive dry summers after the bulb removal, which may have depleted the remaining population if the conditions were not favorable to germinate the remaining seed bank. This may or may not have been a factor, depending on what the winter and spring rain was like in those years.
Why haven't lemon lilies come back to the Idyllwild Area in their former density? Even if a species is extirpated in a given area, if there are nearby areas where a population still exists, one would expect the species to eventually spread to fill its former range. Some species spread rapidly, due to high seed production; good seed dispersal; and not being fussy about where they live. Other species without those characteristics spread very slowly. It seems likely that lemon lilies spread very slowly, since their seed dispersal capability is poor and they can only survive in areas well-protected from predators and with restricted environmental conditions.
In addition, humans may have altered the habitat in the Idyllwild area so much that lemon lilies can no longer thrive in their former numbers. (Note that there are certainly many still-suitable habitats in the Idyllwild area that could support lilies again, even though few lilies remain there now, and hence restoration of lilies to those areas is a very desirable goal.)
The habitat changes can be summarized under three main categories:
- Moisture conditions. Nearly everything humans have done since they came to the Idyllwild area has resulted in less total water in the streams, with the water being available for a shorter period. Lemon lilies are very sensitive to the change in water conditions, both intrinsically and to keep gophers away.
- Erosion / sedimentation. Nearly everything humans have done has also increased erosion throughout the mountain, which can strip lemon lilies from areas next to streams, as well as deprive them of water and habitat by steepening stream banks. The increased sedimentation in some places as well can bury lemon lilies, and/or make them more accessible to gophers.
- Other habitat changes. The loss of the old-growth forest has significantly changed the habitat. A huge amount of the forest in the Idyllwild area was logged from 1875 to about 1905. This removed the giant mature trees that provided shade, kept ground temperatures cooler, and trapped more moisture in the ground, for slower release into the streams. It will be at least several hundred years before we have 500 year old trees again. That may never happen, because the fire regime has been altered as well.
The forest itself now is unnaturally dense with young trees. Fire suppression has allowed young trees to survive that formerly would have been killed by undergrowth fires. This dense forest might now be depleting the soil of its water content more than was the case with the old-growth forest.
The following are some of the main factors that have changed the habitat in the Idyllwild area, not necessarily in order of importance. It should be kept in mind that the combination of these factors are synergistic, making the individual factors worse than if each was the only factor.
- Logging. From 1875 to about 2005, whole sections of the forest near Idyllwild were clear-cut. Robinson and Risher, in their 1993 book The San Jacintos, p. 87, wrote:
It is difficult to visualize today, looking at Idyllwild and its tall pines, that barely a century ago the mountain valley was a logging camp. Whole sections of once magnificent forest were reduced to stumps, with shattered limbs and wood debris scattered about. Furrows criss-crossed the devastated landscape, the result of mammoth logs being dragged to sawmills.Clear-cutting and dragging the logs across and down the very steep slopes of this area, was devastating to the plant and animal communities. San Jacinto Mountain has no deep ground-water; all the run off comes from the current water season. Eliminating the forest shade melted the snow faster, and the furrows caused water to run off faster. This was especially devasting when summer thunderstorms created heavy downpours, removing all the organic debris and then eroding the ground surface. Without the trees to break the rain, and the ground debris to help absorb it without runoff, the water no longer was available to local plants.Rich stands ... were harvested in a forest belt that extended some nine miles ..., from Hall Canyon southeast through Fuller Mill Creek, Pine Cove, Strawberry Valley, Saunders Meadow, and all the way down to the Keen Camp Area.
This was a special tragedy to the forest, since Idyllwild sits right on the edge of being able to support trees, having an average rainfall of just 26 inches, which is roughly the minimum required by trees. Some logged areas almost certainly never became forested again.
It is a sad reminder of this episode that many places in the Idyllwild area were named for the loggers: Hall Canyon, named for Colonel Milton Sanders Hall, the first to commercially log the forest in 1875, using Hall Canyon as his base; Fuller Mill Creek, named for the man who in 1878 or 1879 dragged one of Hall's sawmills over the ridge from Hall Canyon to what is now called Fuller Mill Creek; Saunders Meadow, named for Amasa Saunders who operated a sawmill in Strawberry Valley from 1880 to 1886.
Draft not worked on beyond this point
- Water diverted from the drainages for use by people. (idyllwild, pine cove, campgrounds, "spring water" for sale)
Idyllwild Water District services 1,602 water accounts, "impounding the seasonal flows of Strawberry Creek, capturing as much as possible of very intermittent storm run off, the District replenishes and maintains Foster Lake and its natural underground reservoir". supply "300 acre feet of finished water per year or 100 million gallons per year", and has 28 wells. pine cove, something like 30 million gallons per year.- Cattle grazing. predation / trampling / erosion.
- Introduction of non-native weeds. sucking up the rainfall and ground moisture.
- climate change, including a bad time in the ice age cycle.
- fires
Plans for Restoration of the population In order to bring attention to the diminshed numbers of lemon lilies at San Jacinto Mountain, Kate Kramer, the San Bernardino Forest Botanist for the San Jacinto Mountains, and Dave Stith, organized a Lemon Lily Festival at Idyllwild. Restoration was part of the goal of the Festivals.
The Festivals were major undertakings, requiring a lot of work. An additional problem was scheduling a major event at the time when lemon lilies would be in bloom at the elevations of Idyllwild. Due to other Idyllwild festivals, it was necessary to schedule a major event after most of the lemon lilies had bloomed there. Lemon lilies were still in bloom during the Festivals, but only at higher elevation, requiring a strenuous hike to see them.
As a result, after the sixth Festival in 2015, the organizers of the Festival decided to discontinue it as a major event.
After 2015, the Idyllwild Nature Center continued it as a lower-key event.
Dates of the Festivals:
Major Festivals
- #1 July 16-18, 2010
- #2 July 15-17, 2011
- #3 July 21-23, 2012
- #4 July 13-14, 2013
- #5 July 12-13, 2014
- #6 July 11-12, 2015
Idyllwild Nature Center Events
- #7 July 9-10, 2016
- #8 June 24-25, 2017
- #9 June 23, 2018
- #10 June 22, 2019
- No festival in 2020 and 2021 due to COVID.
- #11 June 18, 2022
- #12 July 15, 2023
Go to:
Copyright © 2016-2023 by Dave Stith and Tom Chester.
Commercial rights reserved. Permission is granted to reproduce any or all of this page for individual or non-profit institutional internal use as long as credit is given to us at this source:
http://tchester.org/sj/species/lilium_parryi/decline_in_idyllwild_area.html
Comments and feedback: Tom Chester
Updated 1 June 2023.