Glen Canyon National Recreation Area. Lees Ferry 10 Acre Riparian Revegetation Project

Transcription

1 Glen Canyon National Recreation Area Lees Ferry 10 Acre Riparian Revegetation Project

2 Project Objectives Establish a 10 acre stand of native vegetation, including Freemont cottonwood, Gooddings willow and Fourwing saltbush at Lees Ferry Maximize successful establishment of native species and minimize amount of future maintenance required. Monitor the environmental health of the ten-acre revegetation project through avian censusing and revegetation monitoring. Maintain stands for the benefit of both wildlife and humans.

3 Lees Ferry Revegetation Overview Site Analysis Planting Design Propagules Site Clearing Tillage Irrigation and Maintanance Monitoring

4 Site Analysis Preliminary soil analysis of 14 evenly spaced points throughout the site - Soil samples at 6,3,6,9 - Salinity, soil type, vegetation and depth to water table Intensive analysis using EM 38 electro conductivity meter and Trimble XTS Pro x25 grid across entire site sampling points with salinity measurements at 2 and 5 - Elevation and location with survey unit - Mapping of data

5

6 Planting Design Determined from synthesis of intensive site analysis data and thresholds established from nine step method (Bertin W. Anderson) 270 Freemont cottonwood 105 Gooddings willow 115 Sandbar willow 140 Inkweed 140 Fourwing saltbush 95 Seepwillow Experimentals 11 Netleaf hackberry, Desert olive, Greasewood, Apache Plume, Shrub live oak, Squawbush, Single leaf ash, Box elder

7

8 Site Clearing and Irrigation Construction D-7 bulldozer, chainsaws and tractor All exotic material cleared and piled in windrows Boater camp saved Tamarisk stand at boat launch saved Driftwood piles saved Valuable habitat along riverbank preserved Hand broadcast of Fourwing saltbush seed Berms graded along road to protect site

9

10

11

12

13

14

15

16

17

18 Propagules, Planting and Irrigation Propagules prepared from cuttings and seed from local genetic stock (1 gallon pots) Planting holes augered 18 diameter and 8 deep or to water table Drip irrigation system construction Beaver Fencing around each individual tree Planting (volunteers?) Irrigated with 8 gallons a day for entire first growing season Periodic weeding and replanting of dead trees

19 Before and After Planting Photos

20

21

22

23

24

25

26 Site Photos Two Years After Planting

27

28

29

30 Site Photos 4 Years After Planting, December 2007

31

32

33

34

35

36

37

38

39

40

41 PROGNOSIS FOR THE FUTURE, Lees Ferry Revegetation As the revegetated plants continue to grow over subsequent years at the Lees Ferry Site, the cottonwood/ willow forest which has started to establish along the lower terrace of the site should grow into a mature, healthy stand of quality riparian habitat. Along the upper terrace, a healthy stand of seep willow, four-wing saltbush, arrowweed and inkweed will continue to establish. Cottonwood and willow plantings on the upper terrace will continue to grow, but because of the 8-15 deep water table they may not mature as quickly as the lower terrace plantings. In years 3-5 we should also begin to see the effects of depth to water table and salinity levels on the plantings. Exotic plant invasion by tamarisk will continue to be problematic on the site. A long term weed management program should be implemented to prevent the reinvasion of tamarisk on the site. A third growing season of irrigation for the native plantings is also recommended for the revegetation site. Giving the plantings a third year of supplemental water will add to the long term success of these plantings. This report concludes the monitoring obligations of the AWPF contract. We recommend that a less frequent long term monitoring program is established for this project. This monitoring will help determine the long term effects of salinity and depth to water table on the establishment of native riparian plant species.

42 Maps from the Glen Canyon Revegetation Master Plan (Draft)

43

44