Livestock management and the conservation of imperiled aquatic species on the Las Cienegas Conservation Area, Arizona

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1 Livestock management and the conservation of imperiled aquatic species on the Las Cienegas Conservation Area, Arizona Jeffrey R. Simms and Karen M. Simms

2 Acknowledgements Dave Gori and Gita Bodner Grant Drennen Retired BLM Range Specialist David Kahrs for his Herp Photos and countless volunteers that made collecting the fisheries and aquatic data possible

3 Introduction Las Cienegas NCA acquired in 1988 from Anamax Mining Corp Special Designations National Conservation Area Area of Critical Environmental Concern Wild and Scenic Area Study Area DEQ Unique Water Designated Critical Habitat for Gila Chub

4 Cienega Creek Stream bisects Chihuahuan Semi-desert Grassland Healthy watershed Elevation Range ft Precipitation Range inches Setting

5 Cienega Creek 3 Naive Fishes Gila chub (E) Gila topminnow (E) Longfin Dace (BLM Sensitive)

6 2 Leopard Frogs and 1 Gartersnake Lowland Leopard Frog (SL) (E) Chiricahua Leopard Frog (T) Mexican Gartersnake (C)

7 Huachuca Water Umbel (E) 1 Listed Plant

8 Cienega Creek - Livestock Management 1990 Decision was made in 1990 to begin fencing livestock out of riparian areas. Livestock management BOs directed BLM in 1994 and 2003 to eliminate warm season grazing continue winter grazing move watering points to upland pastures use lanes up to 3 weeks to cross creek for pasture rotation Creek in warm season pasture completely fenced out by about 1996 Warm season use nearly eliminated

9 Livestock Management Assumptions 1990s 1) Riparian area in 1988 was not at desired future condition when compared to other areas with similar potential - needed rest form livestock (e.g. more trees in seedling & sapling stages and increased density of semi-aquatic and aquatic herbaceous plant cover) 2) Bank damage and past erosion indicated that the cienega and its fragile soil structure was vulnerable to down-cutting with above average flow events 3) Increased tree density would stabilize banks to the point where large flood events would only cause small scale localized channel adjustments 4) Fish populations of topminnow & chub would continue to thrive 5) Neotropical migratory birds would benefit from the increased habitat structure and diversity 6) Riparian vegetation would lead to increased channel roughness on banks and floodplain resulting in increased recharge 7) Control of riparian grazing would help revive the small population of Water Umbel in adjacent wetland but not detectible in Cienega Creek in the early 1990 s 8) Flexible stocking rates would improve ground cover leading to reduced runoff rates and sediment and in washes attenuation/improved ground water recharge 9) Sediment capture on banks and floodplain would slowly raise stream channel elevations reconnecting disconnected flood plains lost to down cutting in the 1890s 10) Riparian vegetation diversity would increase dramatically due to the ecological release effect of reduced levels of summer grazing 11) Flooding and wildfire would keep the creek open and prevent choked conditions

10 Assumption #1: Riparian Proper Functioning Condition (PFC) and Desired Future Condition (DFC) Did the riparian area respond by producing more trees in seedling & sapling stages and increased density of semi-aquatic and aquatic herbaceous plant cover?

11 Total Undercut Bank (meters) Assumption #2 & #3: Did Bank stability and resistance to erosion from floods respond to changes in livestock management? Undercut Bank upper reach lower reach

12 log (individuals per m²) Assumption #4: Did fish populations of topminnow & chub continue to thrive with changes in vegetation and channel structure? 2 Topminnow Density, Lower Reach R² =

13 Assumption #5: Did neotropical migratory birds benefit from the increased riparian habitat structure and diversity? No Specific Data Yes, if the response was the same as the San Pedro RNCA which has had a dramatic increase in bird density and diversity. Assumption: #6 Did riparian vegetation increases lead to increased ground water recharge? Data confounded by draught Yes, theoretically - more flood plain inundation, and flood attenuation leads to improved bank/ground water recharge

14 Assumption #7: Did control of riparian grazing help revive the small population of Water Umbel in Cienega Creek? Yes, HWU was found in only one location on the Las Cienegas NCA in the 1990 s Now there are at least 18 locations as of the fall of 2009

15 Assumption #8: Did Flexible stocking rates improve ground cover leading to reduced runoff rates and sediment and in washes attenuation/improved ground water recharge? Upper reach pool area increased 21% Lower reach pool extent increased by 290%! 2215 m Lower Reach m 2 fall glide marsh pool riffle run 1990 Upper Reach m Lower Reach 864 m m m m Upper 15 Reach 6 63 m m m m 2

16 Assumption #9: Sediment capture on banks and floodplain would slowly raise stream channel elevations reconnecting disconnected flood plains lost to down cutting in the 1890s? Yes, the channel elevation is increasing in many locations So far there has been a 3 foot increase some areas Need another feet to reach flood plain in much of Cienega Creek

17 Assumption #10: Did riparian vegetation diversity increase dramatically due to the ecological release effect of reduced levels of summer grazing? Yes, creek plant diversity increased over the 20 years of riparian monitoring Notable species observed since the original riparian plant surveys in 1990: False Indigo Giant sedge Water pimpernel Large buttercup Black creeper sedge Sycamore Bonpland willow Huachuca Water Umbel (found at 18 locations in 2009)

18 Assumption #11: Did flooding and wildfire keep the creek open and prevent choked conditions? No, more on this coming up!

19 Potential Natural Community PNC & Desired Future Condition

20 Ecological Release The BLM changed its grazing management in 1990 with the eventual retirement of warm season grazing in riparian pastures by 1994 The biological and physical processes that govern aquatic habitat development were no longer constrained by the impact of 1000 head of livestock using riparian habitat

21 Percent Canopy Cover Canopy Cover Average Canopy Cover upper reach lower 1 lower 2 lower

22 Habitat Area Habitat Area Canopy Cover Upper Reach % 26-50& 51-75% % 60% 50% 40% 30% 20% 10% 0% Canopy Cover Lower Reach % 26-50& 51-75% % 100% 80% 60% 40% 20% 0% Canopy Cover

23 Movement Toward Desired Future Condition Aerial images of the Cienega Creek wet headwaters from 1972, 1988, 1995 and 2002 (left to right). Note changes in size and positions of riparian trees and changes in eroding terrace areas.

24 Winter Grazing Segment

25 Summary of Fish Habitat Changes Fish habitat parameters responded in the following manner From 1990 to 2000: Upper Cr - pool riffle run glide marsh Lower CR - pool riffle run glide marsh Avg depth pools Avg habitat width upper reach & lower reach Woody cover Undercut bank Riparian canopy cover

26 Summary of Fish Habitat Changes Fish habitat parameters responded in the following manner From 1990 to 2000: Upper Cr - pool riffle run glide marsh Lower CR - pool riffle run glide marsh Avg depth pools Avg habitat width upper reach & lower reach Woody cover Undercut bank Riparian canopy cover

27 Results Topminnow Surveys ! 20 years!

28 log (individuals per m²) Topminnow Population Trend Topminnow Density

29 What Happened to Topminnow in the Upper Reach?

30 Can Riparian Habitat be Too Healthy for Gila Topminnow? Upper Reach Issues Goodding s willow produced dog-hair thickets Light levels dropped Leaf litter (organic matter) increased dramatically smothering some habitats with decomposing organic matter Primary production algal driven food chain replaced by litter driven food chain DO dropped to less than 2 ppm while lower segment is running above 4 ppm Confounding factors - Drought has caused flows to decrease Stagnant conditions are now common lack of flooding small base flow no riffles to assist in gas exchange Loss of topminnow at one survey sites from drought and one from poor water quality Approx 40% reduction in habitat since the 1990 s

31 Drought & Pond Scum

32 Light, Food Production and Temperature

33 Conclusions Livestock can alter habitat conditions that are positive for some species, Gila topminnow, and negative for others, Huachuca water Umbel Topminnow populations have remained fairly stable in the lower portion of Cienega Creek but have decreased in the upper portion. The upper creek has seen an increase in pool volume, extent of marsh and density of tree canopy cover (increased organic inputs). The upper creek has lost flow volume due to drought conditions. The increase in organic detritus coupled with low stream discharge has resulted in poor dissolved oxygen concentrations that are likely to severely limit the fish populations in the upper creek. Gas exchange (C02 & 02) has been retarded by oily scum from large diatom populations that build up in pool surface film. Increased riparian plant volume and extent does not necessarily improve fish habitat (e.g. springs with small discharge volumes).

34 Scientific Support for Disturbance to Maintain Fish Habitats at Spring Ecosystems NATIVE FISHES, EXOTIC MAMALS, AND THE CONSERVATION OF DERERT SPRINGS - Ash Meadows in Nevada and Dalhousie in central Australia Kodric-Brown & Brown 2007: After springs were fenced and livestock removed, these ecosystems experienced increases in riparian vegetation, reduction of open-water habitat, and extinction of fish populations. Despite manual removal of vegetation to maintain open water habitat, at least one pupfish population went extinct in Ash Meadows, Nevada, and 18 populations, representing four of the five species native to desert springs in the Dalhousie Reserve, Australia also went extinct. To maintain the diversity of aquatic habitats and endemic biota, management of small desert springs must include substantial disturbance. Major disturbance in Australian Springs and North American springs is necessary to maintain habitat structure and native fish species diversity in desert springs Extinct mammalian megaherbivores, aboriginal humans, and domestic livestock historically caused such disturbances Removal of feral livestock has led to the extinction of fish populations in desert springs of North America and Australia Some substitute for mammalian impacts is necessary to restore desert spring habitats and preserve aquatic biotas

35 More Science SALTCEDAR REMOVAL AS A RESTORATION TOOL Kennedy et. al Ash Meadows National Wildlife Refuge, Nevada Saltcedar removal was a highly effective restoration tool because it led to significant increases in pupfish abundance at Jackrabbit Spring Algal productivity increased significantly following saltcedar removal and stable isotope analysis provides conclusive evidence that this drove significant increases in pupfish Pupfish are virtually absent from native downstream reaches because these habitats represent the transition between spring runs that are driven by algae production and cienegas that are detritus dominated Saltcedar abruptly shifts a long segment of Jackrabbit Spring to a detritus-dominated system where dominant organic input is leaf litter that is strongly seasonally pulsed

36 Literature on Springs and Indigenous People Native peoples have been using springs for thousands of years. All of the biodiversity we have now was stewarded by native peoples using these ecosystems essential for survival: water, food, fiber, irrigation and spiritual renewal Supporting Scientific literature Nabham, J.P Plant diversity influenced by Indigenous Management of Freshwater Flora of Quitavac, Sonora, Mexico, in Arid Springs in North America, Ecology and Conservation (ed.stevens, L.E. and V.J. Meretsky). University of Arizona Press. Rea, A.M Historic and Prehistoric Ethnobiology of Desert Springs, in Arid Springs in North America, Ecology and Conservation (ed.stevens, L.E. and V.J. Meretsky). University of Arizona Press.

37 What Happened to the Leopard Frogs & Mexican Gartersnake? The leopard frogs perished from Chytridiomycosis a deadly fungus thought to have come from fogs in the pet trade from Africa. The Mexican gartersnake is a specialist on leopard frogs and fish. Food resources for this species were extremely limited over much of the creek. Gartersnakes are now rarely encountered along the creek.

38 Aquatic and Riparian Ecosystem Function and Processes.. Are the current scientific studies on the right track?