SCOUTING AND COLLECTION TRIPS FOR TRANS-PECOS QUERCUS GERMPLASM: APGA-USFS TREE GENE CONSERVATION PARTNERSHIPS
Shannon S ll1, Emily Griswold1, and Andrew McNeil-Marshall2
1University of California Davis Arboretum & Public Garden
2Lady Bird Johnson Wildflower Center TABLE OF CONTENTS INTRODUCTION 3 SCOUTING AND COLLECTING TRIPS 5 Scou ng trip 1 5 May 10-16, 2016 5 Collec ng Trip 7 Tuesday, August 23, 2016 7 Wednesday, August 24, 2016 7 Thursday, August 25, 2016 7 Friday, August 26, 2016 10 Saturday, August 27, 2016 11 Sunday, August 28, 2016 14 Monday, August 29, 2016 15 Tuesday, August 30, 2016 15 Scou ng trip 2 16 October 30-November 4, 2016 16 PARTICIPANTS 18 Par cipants on the Scou ng or Collec ng trips 18 Ins tu ons that received acorns 19 COLLECTIONS AND GERMPLASM DISTRIBUTION 20 APPENDICES 21 Appendix 1. Collec ng permit for Big Bend Na onal Park 21 Appendix 2. Full list of taxa collected and collec ng notes from the locali es (a ached as a separate Excel Workbook). 28
2 INTRODUCTION The UC Davis Arboretum and Public Garden (UCD ArbPG) partnered with the Lady Bird Johnson Wildflower Center (LBJWC) to target 5 rare and threatened oak species na ve to the Trans- Pecos region of west Texas for scou ng and collec ng in 2016: Quercus carmenensis, Q. depressipes, Q. graciliformis, Q. robusta, and Q. tardifolia.
The genus Quercus is known to have recalcitrant seeds that are not suitable for tradi onal seed banking. The targeted taxa have been selected due to their rarity and their limited distribu on within a concentrated area of west Texas. Due to the small popula on sizes and close proximity of ranges for these species, it was realis c to target mul ple species with the proposed scou ng and collec ng effort. Most of these taxa are not represented in current ex-situ collec ons within the American Public Gardens Associa on Plant Collec ons Network Quercus Mul site Collec on or in ins tu ons par cipa ng in Botanic Garden Conserva on Interna onal’s PlantSearch database.
The far western region of Texas, the Trans-Pecos (Fig. 1), is home to an excep onally high diversity of oaks – 22 species occur here, represen ng almost a quarter of the taxonomic diversity of oaks in the United States. Oak diversity in the Trans-Pecos region is concentrated in a series of “sky island” mountain ranges – the Chisos Figure 1. The Trans-Pecos region of Texas is to the west of the Pecos River, Mountains, Davis and includes nine coun es. Twenty-two oak species occur in this region of Mountains, and Texas. Big Bend Na onal park is in the southern part of Brewster County. Guadalupe Mountains – that are isolated from each other by lowland Chihuahuan desert vegeta on. Due to their isola on, the sky islands of Texas harbor four endemic oak species as well as relict popula ons of species that were previously more widespread. The west Texas mountains also have unique floris c affilia ons with the Sierra Madre Occidental and the Del Carmen-Sierra Madre Oriental of Mexico and serve as the northernmost limit of five Mexican oak species that do not occur elsewhere in the United States.
The sky island mountains of west Texas are well protected within Na onal Parks, Texas State Parks, and Nature Conservancy holdings. However, the oak species in these mountains are s ll
3 vulnerable to climate change. As the climate becomes warmer and drier, their migratory paths are quite limited. For this reason, ex situ conserva on in curated living collec ons will be cri cal for ensuring the long-term survival of these species. For those species that extend into Mexico, capturing the gene c diversity for the popula ons at the northern limit of their range is valuable, especially in the face of climate change. None of the target species for this proposal are ranked as federally endangered or listed as threatened or endangered by the state of Texas. However, most have been ranked with some level of conserva on status by IUCN and NatureServe.
We completed two scou ng trips and one collec ng trip during 2016, as detailed below. One scou ng trip occurred in May, before the collec ng trip. The collec ng trip occurred in late August and a follow-up scou ng trip took place in late October. The scou ng and collec ng trips helped to further knowledge of these oaks, their specific range, and their phenology.
Figure 2. Acorns from Quercus graciliformis collected for the grant.
4 SCOUTING AND COLLECTING TRIPS Scou ng trip 1 May 10-16, 2016 Ini al oak scou ng trip to Chisos Mountains, Big Bend Na onal Park Andrew McNeil-Marshall, accompanied by Nick Richman, Lady Bird Johnson Wildflower Center (LBJWC)
The goal for the first scou ng trip was to determine the loca on of several Q. graciliformis popula ons and a empt to visit a unique popula on Q. carmenensis on Casa Grande peak in the Chisos Mountains, and to cover as much ground as possible to see what will be possible to achieve on a later collec on trip. The secondary goal was to locate a known popula on of Q. tardifolia and other oaks of interest in the Chisos Mountains. There is a very interes ng diversity of oaks in these mountains, the extent and cause of which has not been fully explored.
McNeil-Marshall and Richman hiked for many hours and many miles over the course of four days, covering approximately 25 miles on foot. Much of this hiking was over very rugged terrain (Fig. 3), including one a empt to reach a very high point on Casa Grande peak where there exists a popula on of Q. carmenensis, the only known popula on in the United States.
Very li le sign of acorns or catkins was observed during this trip. Interes ngly, most of the oaks were in the process of shedding last year’s leaves and pu ng on new buds. However, the group did note some loca ons for later collec ng, and iden fied specific trees from which to target later in the year. This trip became Figure 3. McNeil-Marshall hiking the rugged terrain the basis for the trip in August. towards Casa Grande in the Chisos Mountains of BBNP. This is the terrain to hike when searching for Quercus carmenensis. Quercus gravesii and Q. grisea are also found in this local area.
5 Figure 6. Loca ons of individuals and collec ons of Quercus graciliformis and Quercus grisea in Blue Creek Canyon, Big Bend Na onal Park. Upper le inset map shows the specific collec on loca ons for Q. graciliformis. The red line indicates the track for the hiking trail followed by Shannon S ll. The lower right inset map show the extent of the main map window within Big Bend Na onal Park.
Figure 7. Quercus graciliformis popula on from which acorns were collected. The popula on was along a south-facing rock face to the north side of Blue Creek Trail in Big Bend Na onal Park. McNeil-Marshall (le ) and Griswold (right) are hiking up to the Figure 8. Griswold and McNeil- popula on. Marshall collec ng acorns of Quercus graciliformis.
6 Collec ng Trip August 23-30, 2016 Emily Griswold, Shannon S ll (UCD ArbPG), and Andrew McNeil-Marshall (LBJWC)
Tuesday, August 23, 2016 Griswold and S ll traveled to Aus n, Texas on the 23rd. They met Marshall McNeil at airport, purchased groceries and supplies for the trip, and then prepared to leave Aus n the following morning.
Wednesday, August 24, 2016 Griswold, McNeil-Marshall, and S ll, le Aus n and traveled to the Trans-Pecos region of Texas. The first stop of the day was the herbarium at Sol Ross University. Here the trio met with Michael Powell (Fig. 4), an expert on the Figure 4. McNeil-Marshall (le ) and Griswold (right) with Trans-Pecos flora and oaks in Michael Powell at the Powell Herbarium at Sol Ross University. par cular. At the herbarium, the group examine oak specimens from Big Bend Na onal Park and the Davis Mountains and discussed the varia on in these special oaks with Powell. Powell provided further insights into the oaks for which we were searching. A er the visit, the group departed for Big Bend Na onal Park (BBNP), checked in to the BBNP headquarters, and then headed to the accommoda ons at K Bar Ranch within BBNP.
Thursday, August 25, 2016 Thursday was the first day of targeted collec ng, and was the most Figure 5. S ll (le ) and McNeil-Marshall (right) examining one of the first Quercus graciliformis successful day for collec ng on the encountered on the trip, along Blue Creek Canyon Trail. trip. On the southwestern side of BBNP, the group quickly found the target species (Fig. 5) while hiking the Blue Creek Canyon Trail (Fig. 6),. This trail was one that was scouted by McNeil-Marshall and has nice specimens of Q. graciliformis. Along the trail we saw Q. grisea, Q. emoryi, and Q. graciliformis. None of the individuals along the trail had acorns
7 Figure 11. Loca ons of some individuals and voucher collec ons of Quercus along Laguna Meadow Trail, Colima Trail, Boot Spring Trail, and Pinnacles Trail. The group followed a counter-clockwise hike through the trails (start of each segment marked by green circle with black dot). Group visited Laguna Meadow and Boot Spring, which both have rare oak taxa. The red line marks the hiking trail taken by S ll.
8 to collect. Once we proceeded higher into the canyon, we spo ed oaks along a rock face (Fig. 7) up a grade to the north side of the trail. On the inset map in Fig. 6, the dark area just below the gold star is the cave that can be seen in the center of Fig. 7. This was the only popula on that had mature acorns to collect. Figure 8 shows Griswold and McNeil-Marshall collec ng from the popula on.
The trees in the popula on ranged in height from 10-30 feet tall, with a diameter at breast height of 6-15 inches. In accordance with our collec ng permit from BBNP, we collected from 10 individuals, the maximum number of individuals allowable by the permit.
We collected between 30 and 60 acorns from Figure 9. Quercus graciliformis acorns collected from Blue Creek Canyon each specimen (Table popula on. 1). The acorns ranged in size and some of the acorns were tan and brown while others were more green (Fig. 8). Most had light longitudinal striping, which is characteris c of the species. All acorns appeared to be mature enough to collect and germinate. Along with the acorns, we also collected voucher specimens for each individual. Once the accession numbers are assigned by BBNP, the specimens will be distributed to the herbaria.
Quercus graciliformis is a dis nct species that is rela vely easy to iden fy (Fig. 10). There does not appear to be too much hybridiza on with other species in the area. This is important when some other species in BBNP are hybrids, and can be difficult to differen ate.
Figure 10. Leaves and acorns of Quercus graciliformis. 9 Friday, August 26, 2016 For the 26th, two more botanists joined the group for two days. Mickey Merri is a Texas State Forester and he was joined by the re red Texas State Forester for the Trans-Pecos region, Oscar Mestas. Mestas joined the trip to help find oak species and to show Merri some new oak species he had previously not seen.
The hike was started from the BBNP Lodge, located in Chisos Basin and went counter-clockwise around a loop of four trails: Laguna Meadow, Colima, Boot Spring, and Pinnacles (Fig. 11). Along the Laguna Meadow Trail, the vegeta on was different from the previous day due to higher al tude, and the oaks were
Figure 14. S ll collec ng leaves of Quercus graciliformis (20160826-11) along the Pinnacles Trail. Figure 12. Quercus intricata in Laguna Meadow, Big Bend different as well. While rare the Na onal Park, Texas. Inset shows curled leaf margins typical prior day, the first part of the hike for the species. brought Q. grisea, Q. vaseyana, Q. gravesii, and finally Q. intricata. Unfortunately, no individuals had mature acorns, and most had none. The Q. intricata were most abundant in Laguna Meadow (Fig. 12), but there were no acorns. The group also searched for a supposed popula on of Q. carmenensis on the hillsides near Laguna Meadow, as directed by Michael Powell, but were unable to find the species in this area.
In a surprise to the group, we collected foliage from Q. rugosa, along the Colima Trail on the way towards Boot Spring. This taxon was not known to be in this area, and maybe had not been recorded from BBNP. Also along the Colima Trail, there were oaks that looked like similar to Q. tardifolia, but are likely large-leaved Q. gravesii. Dis nguishing between these taxa is difficult.
Once we reached Boot Spring, we did find the loca on for the type specimen of Q. tardifolia. However, the exact tree is now deceased (Fig. 13), and we were unable to collect acorns or vouchers of anything that was defini vely Q. tardifolia. This species, based upon one individual, might be of hybrid origin and needs further taxonomic work. We did collect some Figure 13. Type specimen, or what is remaining, of Quercus tardifolia in Boot Spring. 10 vouchers of some individuals that could be Q. tardifolia, but there were no acorns.
On the way down the Pinnacles Trail there were many Q. grisea, which were not nearly as abundant along the Laguna Meadow or Colima Trails. We also found more Q. gravesii and Q. rugosa, and some plants that we believe to be Q. graciliformis (Fig. 14), even though they had not been collected in this area of the park.
Ul mately, the 26th was not frui ul for collec ng acorns. However, the group was able to iden fy fine individuals of some rare oaks, and helped map a couple of new popula ons for targeted taxa.
Saturday, August 27, 2016 On the 27th, the group was again accompanied by Mestas and Merri . The goal was to hike the Lost Mine Trail before joining a smaller trail to hike along an area known as the Chinese Wall, in the hopes of finding Q. carmenensis on the bluffs below Casa Grande peak (Fig. 15). The popula on of Q. carmenensis reportedly located on the bluffs (Fig. 16) is the only
Figure 15. Hike to the bluffs below Casa Grande peak to try to find a puta vely known popula on of Quercus carmenensis. 11 Figure 16. View from the bluff below Casa Grande Peak looking north. The known vouchered US popula on of Quercus carmenensis is reportedly along the le side of the photo on the upper bluffs. Griswold can be seen moving along the rugged terrain (see white arrow). vouchered collec on in the United States for this primarily Mexican species. On the way up the Lost Mine Trail, several oaks were iden fied, including Q. emoryi, Q. grisea, Q. vaseyana, and Q. gravesii.
Quercus carmenensis is a scrubby oak, similar to Q. intricata. Individual plants in the known locality that resembled Q. carmenensis (Fig. 17), but could not be posi vely iden fied. Voucher specimens were collected but no mature acorns were present. The oaks in the bluffs below the peak appear to be hybridizing, and some individuals look more like Q. intricata, while others more resemble a scrubby Q. grisea. Ul mately, molecular taxonomic work may help to sort these species, and this would be an ideal Figure 17. An individual that appears similar to locality to collect plants for further study. Quercus carmenensis, but is uncertain. One However, the region is rugged and dis nguishing characteris c for the species, according difficult to access. to Michael Powell, is the acorn cap that is reddish with white tu s of trichomes.
12 Figure 18. Loca on of the type, and only, Quercus robusta popula on along the Oak Springs Trail.
In the a ernoon, Griswold, McNeil- Marshall and S ll drove to the west side of the park to visit the type locality (Fig. 18) for Quercus robusta, a large hybrid oak (Figs. 19 & 20). While there were no acorns to collect, we did collect vouchers specimens from most of the individuals in the popula on (Appendix 1). These specimens could be useful for popula on gene c studies to be er Figure 20. Leaves of Quercus reveal the parentage, robusta. which is puta vely Q. Figure 19. Quercus robusta from the emoryi and Q. gravesii. type locality along Oak Springs Trail.
13 Sunday, August 28, 2016 On Sunday, Griswold, McNeil- Marshall, and S ll le BBNP (Fig. 21) to head to the Davis Mountains to search for Q. depressipes. Unfortunately, the group was unable to access the Nature Conservancy land where the species occurs, and therefore unable to collect leaves or acorns Figure 21. S ll, Griswold, and McNeil-Marshall (L-R) at the K from this rare species. It is unclear Bar Ranch house on the last morning in Big Bend Na onal if the Nature Conservancy will Park. allow collec ng in the future, but it was clear that ex situ collec ng was not a current priority for the management of the species. This was different than our understanding when the grant was submi ed, and the decision was disappoin ng.
Despite not being allowed to collect the targeted species, acorns of three more common species, Q. hypoleucoides and Q. grisea , and Q. emoryi, were collected from the Davis Mountains (Fig. 22) in Jeff Davis County, Texas.
Figure 22. Collec ons loca ons for three common oaks from the Davis Mountains.
14
Figure 23. Chihuahuan Desert Botanical Garden and Nature Center entrance.
Monday, August 29, 2016 On Monday, we visited Chihuahuan Desert Botanical Garden and Nature Center (CDBGRC) (Fig. 23) to deliver some oak plants that McNeil-Marshall was dona ng to the garden, and to tour the garden. CDBGRC has collec on of most of the Trans-Pecos oaks, such as Q. hinckleyi (Fig. 24), as well as nice collec ons of other iconic Trans- Pecos taxa, such as Yucca. Their collec ons would make a nice addi on to the Quercus Mul site Collec on in the future due to their collec ons and their loca on in the middle of an area of high oak diversity. A er our visit to the garden, we traveled back to Aus n. Figure 24. Quercus hinckleyi at the Chihuahuan Desert Botanical Garden and Research Center. Tuesday, August 30, 2016 On Tuesday we tour the LBJWC and their oak collec ons. LBJWC has a large collec on of oaks from Texas, many of which are located in the Texas Arboretum (Fig. 25). The Arboretum is being established with heritage plants from around the state.
In the a ernoon, S ll and Griswold traveled back to California, thus concluding the trip.
Figure 25. Texas Arboretum at LBJWC. The Arboretum has heritage oaks from around the state.
15 Scou ng trip 2 October 30-November 4, 2016 Subsequent oak scou ng trip to Chisos Mountains, Big Bend Na onal Park Emily Griswold (UCD ArbPG) The goal for this second scou ng trip was to look for maturing acorns from species the group could not collect in August, to note phenological changes that happened during the year, and to iden fy future collec on loca ons. The 2016 growing season had a fair amount of precipita on, and the vegeta on was much more lush than in previous visits by the researchers.
Griswold drove into the park on October 31, stopping to look at some oaks on the way into the Chisos Mountains. Due to the high summer rainfall, many of the oaks had put on significant addi onal growth. The new leaves of Q. grisea (Fig. 26), with long shoots of fall growth with larger more green leaves, were significantly larger than the previous spring and summer growth from this year. The difference between leaf size, color, and internode length was quite striking.
On November 1, Griswold did an out and back hike from the Chisos Mountain Lodge to the Figure 26. Leaves of Quercus grisea, showing long pe oles and Window Trail to the Oak Springs larger leaves due to heavy summer and fall rains. Trail. There were a lot of oaks along the Window Trail. Quercus gravesii and Q. emoryi were common as well as a whole series of hybrids between them (Fig. 27). Quercus emoryi typically has small, thick evergreen leaves with en re margins or spinose teeth, and a short hairy pe ole. Quercus gravesii typically has larger deciduous leaves and larger lobes, and a long, glabrous pe ole. The hybrids show a complete range of intermediate characters (Fig. 27). It would be worth returning to the Window Trail to document this varia on more thoroughly, especially as these are puta ve hybrids between an evergreen and deciduous oak species. Combined with the differences in leaf morphology due to the heavy rains, this region would be ideal to study varia on in molecular and morphological taxonomy.
Griswold then revisited the Q. robusta loca on and s ll did not see any evidence of flowering or frui ng.
16 Figure 27. Leaves of Quercus gravesii (far le ), Quercus emoryi (far right), and hybrids between the two taxa, showing leaf varia on along the Windows Trail in Big Bend Na onal Park.
On November 2, Griswold revisited the Laguna Meadow Trail loop that we had taken in August. While there were immature acorns on Q. gravesii (Fig. 28) and Q. arizonica, there were no acorns on the rare targeted taxa.
The second scou ng trip makes more certain that the acorns were not present on most of the targeted taxa, rather than just not being available during the collec ng trip in August. While this is not ideal for the group, it does provide some relief that the researchers made a good effort to collect the taxa. Unfortunately, oaks can have uneven frui ng between years, which can cause Quercus collec ng consterna on.
Figure 28. Quercus gravesii on the Laguna Meadow Trail showing immature acorns.
17 PARTICIPANTS
Par cipants on the Scou ng or Collec ng trips
Shannon S ll and Emily Griswold UC Davis Arboretum and Public Garden One Shields Ave. Davis, CA 95616 (530) 752-7822 sms [email protected]
Andrew McNeil-Marshall and Nick Richman Lady Bird Johnson Wildflower Center 4801 La Crosse Ave Aus n, TX 78739 (512) 232-0155 amm@wildflower.org
Mickey Merri Regional Urban Forester Texas A&M Forest Service P.O. Box 1763 Alpine, TX 79831 (432) 837-3000 mmerri @ s.tamu.edu
Oscar Mestas Regional Urban Forester (re red) Texas A&M Forest Service
18 Ins tu ons that received acorns
UC Davis Arboretum and Public Garden Shannon S ll and Emily Griswold One Shields Ave. Davis, CA 95616 (530) 752-7822 sms [email protected]
Bartle Tree Research Laboratories and Arboretum Greg Paige 13768 Hamilton Road Charlo e, North Carolina 28278 (704) 588-1150 Ext. 141 gpaige@Bartle .com
Chihuahuan Desert Botanical Garden and Nature Center Leslie Spicer 43869 State Hwy. 118 Fort Davis, TX 79734 (432) 364-2499 [email protected]
Boyce Thompson Arboretum Cathy Babcock 37615 US Hwy 60 Superior, AZ 85173 (520) 689-2723 cbabcock@cals.arizona.edu
Lady Bird Johnson Wildflower Center Andrew McNeil-Marshall 4801 La Crosse Ave Aus n, TX 78739 (512) 232-0155 amm@wildflower.org
19 COLLECTIONS AND GERMPLASM DISTRIBUTION
For the grant, only one of the targeted taxa were collected. The other taxa did not produce acorns this year. The acorns for Q. graciliformis were distributed to the partner ins tu ons Lady Bird Johnson Wildflower Center, Chihuahuan Desert Botanical Garden and Nature Center, Boyce Thompson Arboretum, and Bartle Tree Research Laboratories and Arboretum. While part of the Mul site oak collec on, the University of California Botanic Garden opted not to receive acorns for this species due to the larger size. They have limited space and only wanted species that might be smaller in stature. Remaining acorns may be sent to gardens in Mexico or to other interested ins tu ons. Sending the acorns to Mexico has been problema c due to import restric ons within that country. The arboretum at UNAM Puebla was offered, but is not interested in receiving, acorns, due to this restric on.
According the proper collec on guidelines, permits were required for those taxa collected in BBNP. A valid collec ng permit is held by LBJWC (Appendix 1). Material for up to four herbarium voucher specimens was collected and will be distributed to at least three herbaria when the Na onal Park System accession numbers are procured and assigned to the voucher specimens. S ll is currently working with BBNP staff to receive the proper accession numbers and labels. The voucher specimens are currently held at the UC Davis Herbarium (DAV), and one specimen will be distributed to both Lady Bird Johnson Wildflower Center and The University of Texas herbarium (TEX) in Aus n, Texas. Another specimen may be sent to Sol Ross University herbarium.
Table 1. Targeted Quercus taxa in which acorns were collected for the grant, along with the voucher collec on number. See Appendix 2 for full list of taxa collected and collec ng notes from the locali es. Date Collec on Species Vouchers Seeds Longitude La tude number 8/25/2016 S ll 20160825-01 Quercus graciliformis 4 32 29.23287 -103.32129 8/25/2016 S ll 20160825-02 Quercus graciliformis 4 42 29.23272 -103.321 8/25/2016 S ll 20160825-03 Quercus graciliformis 4 60 29.23271 -103.3207 8/25/2016 S ll 20160825-04 Quercus graciliformis 4 37 29.23273 -103.32078 8/25/2016 S ll 20160825-05 Quercus graciliformis 4 48 29.23271 -103.32089 8/25/2016 S ll 20160825-06 Quercus graciliformis 4 45 29.23295 -103.32209 8/25/2016 S ll 20160825-07 Quercus graciliformis 4 42 29.23305 -103.32233 8/25/2016 S ll 20160825-08 Quercus graciliformis 4 56 29.23304 -103.32246 8/25/2016 S ll 20160825-09 Quercus graciliformis 4 32 29.23287 -103.32129 8/25/2016 S ll 20160825-10 Quercus graciliformis 4 42 29.23272 -103.321
20 APPENDICES Appendix 1. Collec ng permit for Big Bend Na onal Park
21 22 23 24 25 26 27 Appendix 2. Full list of taxa collected and collec ng notes from the locali es (a ached as a separate Excel Workbook).
28