4_k__-_Crystal_Springs_Re-vegetation_Plan.pdf

Carson Slough and Crystal Spring Revegetation | Final Report i

1 ABSTRACT

The following revegetation/restoration plan was prepared for the Ash Meadows National Wildlife Refuge (AHME). This plan describes measures to establish desired native plants within the footprint of proposed channel reconstructions in the Upper Carson Slough and Crystal Spring Management Units. Additionally, this plan describes measures to remove non-native, invasive species that, if left untreated, could reduce native species establishment and survival throughout the AHME. The treatment of non-native, invasive species includes areas where monocultures of these plants have developed, as well as a few sites that have potential for invasion following restoration actions such as the removal or modification of Crystal and Peterson Reservoirs. This document also includes plans for planting the former Mud Lake Reservoir and abandoned agricultural fields that have been slow to recover.

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TABLE OF CONTENTS

1 Abstract ..................................................................................................................................... i

2 Introduction

3 Prioritization of Revegetation and Weed Treatments in Conjunction with Spring Restoration Efforts

3.1 Historical Conditions

3.1.1 Disturbance Regimes

3.2 Existing Conditions

3.3 Desired Future Conditions

4 Phases of Wetland Revegetation

4.1 Plant Propagation

4.2 Plant Salvage

4.3 Weed Treatment and Revegetation Efforts

4.3.1 Weed Removal

4.3.2 Coordination of Weed Removal Efforts

4.3.3 Additional Weed Concerns

4.4 Preparation of the Soil Surface

4.5 Planting and Irrigation

4.5.1 Planting

4.5.2 Irrigation

4.6 Monitoring and Further Weed Removal Efforts

5 Upper Carson Slough

5.1 Weed Treatments within Upper Carson Slough

5.2 Fairbanks Spring Channel

5.3 Soda Spring Channel

5.4 Rogers Spring Channel

5.5 Longstreet Spring Channel

5.6 Five Springs Channel

6 Crystal Spring Management Unit

6.1 Weed Treatments within the Crystal Spring Management Unit

6.2 Forest and Kings Spring Channels

6.3 Bradford Spring Channel

6.4 Crystal Spring Channel

7 Revegetation following Reservoir Modifications or Removals

7.1 Crystal Reservoir

7.2 Mud Lake Dam Reservoir

7.3 Peterson Reservoir

8 Revegetation of Abandoned Agricultural Fields

8.1 Soil Assessment and Amendments

8.2 Planting

8.3 Irrigation

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8.4 Monitoring of Revegetation Efforts

8.5 Agricultural Field Selection for Active Revegetation

8.6 Point of Rocks

8.7 Longstreet

9 Conclusion

10 Literature Cited

Carson Slough and Crystal Spring Revegetation | Final Report 1

2 INTRODUCTION

The following revegetation/restoration plan describes methods to establish desired native plants throughout the Ash Meadows National Wildlife Refuge (AHME). AHME is located east of Death Valley National Park and south of Amargosa Valley, NV (Figure 2-1). Habitat restoration activities are ongoing at AHME, and plans for future restoration projects are in development.

This revegetation plan is designed to allow managers to prepare for and implement these projects.

Revegetation efforts hasten the habitat restoration process and are especially important in arid habitats, where plant succession is slow. Additional benefits of revegetation include reduced soil erosion, improved streambank stability, improved upland and riparian wildlife habitat, and decreased spread of non-native, invasive plants. Active revegetation of wetland areas and weed treatments are the highest priority. These actions will have the greatest positive effect on establishing and maintaining native plants throughout the AHME.

In order to formulate this plan, historical environmental conditions, existing vegetation types, and desired future conditions were explored. We focused extensively on weed distributions and removal strategies because weeds are often the biggest hurdle in restoration efforts. This plan provides details for propagation and planting of desired species and suggestions for soil amendments for revegetation of abandoned agricultural fields. A general monitoring protocol is also suggested. This revegetation plan will require refinement in the near future because restoration plans are still in development for most of these areas.

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Figure 2-1. Location of Ash Meadows National Wildlife Refuge (outlined in red).

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3 PRIORITIZATION OF REVEGETATION AND WEED TREATMENTS IN CONJUNCTION WITH SPRING

RESTORATION EFFORTS

This revegetation plan is intended to complement current and future restoration efforts throughout the AHME and specifically within the Upper Carson Slough (UCS) and Crystal Spring Management Units (CMU). Revegetation efforts and weed treatments are proposed for five spring systems within the Upper Carson Slough Management Unit (Fairbanks, Soda, Rogers, Longstreet and Five Springs) and four springs within the Crystal Spring Management Unit (Bradford, Kings, Forest, and Crystal). Planting recommendations are presented for existing and former reservoirs for which removal or modification is being recommended in the UCS and CMU restoration plans; specifically Crystal, Peterson and Mud Lake Dam Reservoirs.

Additionally, the plan prioritizes treatment areas for non-native, invasive plants (i.e., weeds).

Revegetation efforts and weed treatments are prioritized in light of limited funding and the threat of continued invasion by various weeds. Rapid and cost-effective revegetation may include salvage of plant material prior to channel construction and replanting immediately following channel completion. Apart from construction areas, places dominated by weeds throughout Ash Meadows should be treated and planted. Existing weed patches serve as propagule sources resulting in the continued spread of invasive plants. Weed patches that overlap within proposed spring outflow channels are discussed with regard to each respective channel. In most cases, weed removal would be most effective if it was completed prior to the commencement of construction efforts. Construction efforts increase the threat of further weed invasion by clearing land previously occupied by native plants. Therefore, continued weed treatment and revegetation efforts are necessary following channel construction.

If modified or removed, former and existing reservoirs will require active revegetation. If weeds are treated prior to or concurrently with reservoir draining, the likelihood of further invasions will be reduced. At the present time, abandoned agricultural fields are in various stages of passive recovery and in varying degrees of weed invasion. Fields that are slow to recover and have high cover of non-native plants are recommended for weed treatments and active revegetation as funds become available.

Planting within channel construction footprints will be most cost effective and successful if areas of high soil moisture can be planted concurrently with construction efforts. Throughout much of the AHME, native wetland plants are abundant within the vicinity of stream channels, and favorable environmental conditions, especially high soil moisture, promote further establishment of wetland plants. The rapid establishment of native species will reduce the potential establishment of invasive, non-native species. Active planting efforts and subsequent seed dispersal will also encourage passive establishment of native vegetation within the AHME.

Complete restoration of AHME requires the establishment of both wetland and upland plant communities; however, this will not be achieved quickly or inexpensively. Given that plant establishment in arid and semi-arid environments are responses to exceptional events as opposed to average conditions (Westoby 1980), upland restoration in arid environments is

4 Otis Bay Ecological Consultants extremely challenging and expensive. Plant succession in these systems may require decades if not longer to establish climax plant communities. Managers should be aware that revegetation of upland communities will be a slower process than wetland revegetation.

Some upland areas will likely become marshes following channel restoration. Postponing the planting of upland areas that are expected to become marshes until areas of high soil moisture have stabilized will avoid costly mistakes. Plants will not survive if they are planted in areas that are too moist or too dry.

Prior to implementation, revegetation projects generally require between one and two years to allow enough time to collect seed, take cuttings and/or otherwise propagate plant materials.

Given that only native ecotypes are to be used onsite and that channel construction is already underway, a fraction of ideal planting rates are proposed in this report so that the AHME can implement this plan as quickly as possible with available funds. Ideal planting rates were estimated based on the cover of species reported as defining vegetation alliances by NatureServe (accessed June 30, 2009). This amount of cover can be interpreted as a final goal for active revegetation efforts. Vegetation alliances were identified as being mesic or dry based on whether or not “flooding” was included in the alliance name. Planting rates proposed in this report are 10% of the ideal for mesic alliances and 20% of ideal for dry alliances. Mesic alliance planting rates are less because these plants take less time to increase in cover.

If seed is available, wetland plants can be seeded within the gently sloping, mesic banks near newly constructed channels. This strategy has worked well at School Springs and Fairbanks Spring in AHME (Carl Lundblad, pers. comm.). Seeded Sporobolus also established in a burn area. The area was seeded in May of 2009 and watered daily throughout the summer (Carl Lundblad, pers. comm). If resources are available, this process could be repeated at other sites throughout the AHME. However, seeding is not recommended in the upland areas due to the need to collect large amounts of seed from plants on site, harsh site conditions and limited plant establishment in past seeding efforts in AHME.

If existing seed is abundant, it would be worthwhile to try seeding as an experimental revegetation strategy. In the spring of 2010, quailbush (Atriplex lentiformis) germination was observed at numerous sites throughout AHME. This species favors disturbed sites. Species that favor disturbed sites often act as pioneers, facilitating the establishment of later successional plants. Refuge restoration crews should experiment by planting quailbush and monitoring to determine whether this species facilitates establishment of more desirable species if they are seeded under these readily-established shrubs.

However, given the difficulties of establishing native plants in this ecosystem from seed, this plan focuses on the usage of containerized plants and salvage plant materials. Using mature plants is more likely to result in the successful plant establishment (Bainbridge 2007) and may result in increased species diversity (Middleton et al. 2010).

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3.1 Historical Conditions

Reconstructing historical conditions can be a challenging exercise due to a very limited amount of existing information. Sources examined to reconstruct the vegetative communities of AHME prior to present time include cadastral surveys, previous reports, expedition notes, summaries of plants with ethnobotanical uses, and historic aerial photographs.

Cadastral surveys (i.e., General Land Office surveys) offer some of the earliest accounts of the western United States. They were conducted in accordance with the Public Land Survey System (PLSS) which required that certain features be noted in the survey. These include the distance along a survey line where a settler’s claim, river, creek, swamp, marsh, springs, lakes or pond is crossed. AHME was surveyed in 1881 and 1882 (Figure 3-1). Several of the springs were noted and some of the wetlands were delineated as “marsh” or “swamp”. The surveyor also noted the presence of sagebrush and bunchgrasses. Fine-scale details about the historic vegetation patterns are difficult to discern from the survey data.

Threloff (1992) reviewed the notes associated with the General Land Office (1881-82) surveys and interpreted the flow patterns of the Fairbanks Spring outflow channel. At the time of these suveys, braided (or anastomosing) channels flowed out of Fairbanks, Roger, and Longstreet Springs to create a slough. The construction of a concrete water control structure in 1925 altered the hydrology of AHME for irrigation. A change in vegetation would have resulted from this change in hydrology. Based on the historical description of this area compared with other sites with similar hydrology, it is likely that this site would have supported more meadow vegetation at the time of the 1881-82 surveys.

Threloff (1992) discusses several other anthropogenic disturbances and changes in vegetation that have occurred within the refuge. For example, in 1966 peat was mined which involved draining the wetlands and removing the top six feet of substrate. In 1969 land was cleared and leveled for agriculture and spring outflows were modified for irrigation. All of these disturbances resulted in reduced area and connectivity of wetland landscapes in AHME.

Threloff (1992) also addresses an increase in cattails within AHME. Botanist Frank Coville, who was part of the Death Valley Expedition, noted that cattails “occurred sparingly” at several locations, a large contrast to the 300+ acres currently dominated by Typha (Bio-West 2010).

Threloff conjectures that the climax plant community of these desert springs consists of bulrush, grasses, and sedges.

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Figure 3-1. Cadastral surveys of the Ash Meadows National Wildlife Refuge from 1881 and 1882.

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The Death Valley Expedition of 1891 provides a detailed account of the location and abundance of shrubs and trees observed at that time within AHME and the nearby vicinity (Table 3.1).

Within Ash Meadows, explorers found abundant Atriplex confertifolia, Atriplex hymenelytra and Atriplex parryi occurring in alkaline areas. They made note of Fraxinus velutina, Salix exigua and Pluchea sericea commonly occurring in and around the springs, as well as a general abundance of Prosopis glandulosa and Prosopis pubescens. Within a broader radius of AHME (approximately 50 miles; refer to labeled regions in Figure 3-1), we find mention of Atriplex confertifolia, Atriplex polycarpa, Ephedra nevadensis, Hymenoclea salsola, Krameria erecta, Larrea tridentata and Sarcobatus vermiculatus, all occurring commonly in lowland areas.

A number of Native American tribes traditionally resided within the vicinity of AHME. While many tribes traveled to the area for seasonal subsistence, the Southern Paiute and Western Shoshone were thought to be the most permanent year-round residents (Figure 3-2) (Fowler 1986; Rhode 2002). Ethnobotanical accounts detailing those tribes’ uses of regional plants give us some idea of species historically occurring in the area. Prominent species used by local tribes and slated for current revegetation efforts include Juncus balticus, Distichlis spicata, Lycium andersonii, and Anemopsis californica, among many others; 70% of the species suggested for revegetation efforts are mentioned in the Death Valley Expedition and/or ethnobotanical accounts as being historically present in the region, with approximately 10% specified as occurring in Ash Meadows.

Ethnobotanical accounts of Helianthus annuus, or common sunflower, are an interesting point to consider within the question of common sunflower’s nativity. While Helianthus annuus thrives on disturbance and appears ‘weedy’ throughout AHME, ethnobotanical accounts list it as a food source for every tribe historically residing in the area (Fowler 1986). Common sunflower is classified as native by the USDAplants database, with no control measures given for Nevada or any other western state, and it is not listed by the California Invasive Plant Council as being a species of concern (California Invasive Plants Database accessed August 15, 2011).

This discrepancy between common sunflower’s alleged nativity and its weedy behavior may be due to the fact that Helianthus annuus is a species capable of great genetic variability and adaptability. In a 2008 study on the genetics of weedy sunflowers, researchers found that weedy and non-weedy populations grew in close proximity to one another, and that weedy populations had more genetics in common with adjacent wild populations than with other weedy stands that were farther away (Kane and Riesberg 2008). They interepreted this to mean that weediness had likely evolved many times within the species.

Regardless of possible or historic nativity, Helianthus annuus forms dense stands throughout present-day AHME that may displace endemic species (C. Baldino, pers. comm.). Common sunflower is therefore a species of concern, and its treatment is discussed in more detail in “Section 4.3; Weed Treatment and Revegetation Efforts.”

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Figure 3-2. Locations of Native American tribal lands in the vicinity of Ash Meadows.

Sources = Fowler (1986) and Rhode (2002).

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Table 3.1 Plants of Ash Meadows National Wildlife Refuge. The nativity, Native American tribes who used these plants, and location of Death Valley Expedition observations within a 50-miles radius of AHME are given. PU= Paiute; S= Shoshoni; OVP= Owens Valley Paiute; PN= Panamint; WS= Western Shoshone; C= Chemhuevi; K= Kawaiisu; NP= Northern Paiute; NSP = Nevada Southern Paiute; U= Unspecified; NNP= Nevada Northern Paiute; WA= Washoe. Sources = Fowler (1986), Merriam (1893), Moerman (2009), and Rhode (2002).

Species Status Used by Tribes Found in Death Valley Expedition

(w/in 50 mi of AMNWR) Ephedraceae (Mormon Tea)

Ephedra nevadensis Native PU, S, OVP, PN Pahrump Valley, Indian Spring Valley

Amaranthaceae (Amaranth)

Amaranthus blitoides Native K

Amaranthus retroflexus Introduced K

Anacardiaceae (Sumac)

Rhus trilobata Native P, NSP, WS, C

Apocynaceae (Dogbane)

Amsonia tomentosa Native OVP

Apocynum cannabinum Native PU, NSP, C, OVP, WS

Asclepidaceae (Milkweed)

Asclepias erosa Native OVP, WS, PN

Asclepias fascicularis Native OVP, WS, PN

Asclepias speciosa Native PU, OVP, WS, PN

Asteraceae (Sunflower)

Aster subulatus var. ligulatus Native K

Chaetadelpha wheeleri Native NNP

Chrysothamnus nauseosus Native S, WS

Cirsium mohavense Native WS, PU, NSP, C, OVP, PN

Encelia farinosa Native WS, PU, NSP, C

Encelia viginensis Native K

Enceliopsis nudicaulis var. corrugata Threatened S

Gutierrezia microcephala Native WS

Helianthus annuus Native P, OVP, PN, WS, K, WA, NP

Iva axillaris ssp. robustior Native PU, S

Pluchea sericea Native PU, NSP, C, PN Ash Meadows, Pahrump Valley, Death Valley

Porophyllum gracile Native PU, S

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Psathyrotes annua Native PU, S, C, NSP, WS, OVP

Psathyrotes ramosissima Native PU, S, C, NSP, WS, OVP

Stephanomeria pauciflora var. ? Native PU, NSP, C

Xanthium strumarium Native NP

Xylorhiza tortifolia var. tortifolia Native U

Boraginaceae (Borage)

Amsinkia tesselata Native PN, K, PU, NSP, C, WS, OVP

Heliotropium curvassavicum Native PU, S

Brassicaceae (Mustard)

Descurainia pinnata Native PU, NSP, OVP, PN, C, WS, NP, WA

Descurainia sophia Introduced PU, NSP, OVP, PN, K, NP

Lepidium lasiocarpum var. lasiocarpum Native K

Physaria chambersii Native PU, S

Stanleya pinnata var. ? Native PU, S, NSP, C, PN, WS, K, NNP

Oasis Valley

Thelypodium integrifolim ssp. affine Native PU, NSP, C, OVP

Cactaceae (Cactus)

Echinocactus polycephalus Native PU, NSP, C, PN, K, OVP Indian Spring Valley, Ash Meadows

Echinocereus engelmannii Native PN, PU, NSP, C

Opuntia basilaris var. basilaris Native S, PN, K, PU, NSP, C, WS, OVP, WA

Opuntia echinocarpa Native P, NSP, C, WS Death Valley, Pahrump Valley

Opuntia ramosissima Native Indian Spring Valley

Chenopodiaceae (Goosefoot)

Allenrolfea occidentalis Native NNP Death Valley

Atriplex canescens ssp. Canescens Native S, PU, NSP, C, OVP, WS Oasis Valley, Indian Spring Valley, Pahrump Valley

Atriplex confertifolia Native NP, NSP, PU, C Oasis Valley, Indian Spring Valley, Pahrump Valley, Ash

Meadows

Atriplex hymenelytra Native Death Valley, Ash Meadows, Oasis Valley, Amargosa

Canyon

Atriplex lentiformis ssp. torreyi Native Amargosa Canyon

Atriplex parryi Native Ash Meadows, Oasis Valley

Atriplex polycarpa Native Oasis Valley, Pahrump Valley

Chenopodium album Introduced PU, OVP, PN, WS, K, NP

Grayia spinosa Native Oasis Valley

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Krascheninnikovia lanata Native P, S, WS, PN

Sarcobatus vermiculatus Native P, NP Oasis Valley

Suaeda moquinii Native PU, S, NSP, C, WS, OVP

Cucurbitaceae (Gourd)

Cucurbita palmata Native WS

Euphorbiaceae (Spurge)

Chamaesyce albomarginata Native S, PU, NSP, C, OVP, WS, K

Chamaesyce polycarpa Native S

Fabaceae (Legume or Pea)

Acacia greggii Native NSP, C

Prosopis glandulosa var. torreyana Native K, OVP, PU, NSP, C, PN, WS Death Valley, Amargosa Canyon, Ash Meadows, Indian

Spring Valley

Prosopis pubescens Native PU, NSP, C, OVP, PN, WS Death Valley, Amargosa Canyon, Ash Meadows, Indian

Spring Valley

Psorothamnus fremontii var. fremontii Native P, S, C, NSP, WS, OVP

Krameriaceae (Rhatany)

Krameria erecta Native PU, NSP, C, WS

Krameria grayi Native PU, S

Lamiaceae (Mint)

Marrubium vulgare Introduced PU, K

Salazaria mexicana Native Oasis Valley, Indian Spring Valley

Salvia columbiariae Native PU, NSP, C, OVP, PN, WS, K

Salvia dorrii Native PU, NP, S, NSP, C, OVP, WS, K

Loasaceae (Loasa)

Eucnide urens Native South Desert Ranges

Lythraceae (Loosestrife)

Lythrum californicum Native K

Malvaceae (Mallow)

Sphaeralcea ambigua Native S, WS, PU, NSP, C, OVP, PN

Nyctaginaceae (Four o'clock)

Mirabilis bigelovii Native PU

Oleaceae (Olive)

Fraxinus velutina Native PU, NSP, K, C, OVP

Menodora spinescens Native Oasis Valley, Indian Spring Valley

Onagraceae (Evening Primrose)

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Oenothera elata ssp. hirsutissima Native OVP, PN

Papaveraceae (Poppy)

Argemone corymbosa Native PU, NSP, K, C, OVP, WS

Plantaginaceae (Plantain)

Plantago major Introduced PU, S, K

Plantago ovata Native WS

Polemoniaceae (Phlox)

Eriastrum eremicum ssp. eremicum Native PU

Polygalaceae (Milkwort)

Polygonaceae (Buckwheat)

Chorizanthe rigida Native Death Valley, Amargosa Desert, Oasis Valley, Indian Spring

Valley

Eriogonum inflatum var. deflatum Native K, OVP, PU, NSP, C, PN, WS

Eriogonum inflatum var. inflatum Native K, OVP, PU, NSP, C, PN, WS

Rumex crispus Introduced PU, NP, S, OVP, PN, WS, K, NNP

Rumex hymenosepalus Native P, WS, K

Ranunculaceae (Buttercup)

Delphinium parishii ssp. parishii Native PN, OVP, K

Rutaceae (Rue)

Thamnosma montana Native PU, S, NSP, C, PN, WS, K Indian Spring Valley

Salicaceae (Willow)

Populus fremontii ssp. Fremontii Native K Pahrump Valley

Salix exigua Native NP, OVP, PU, NSP, C, PN, WS

Death Valley, Amargosa Canyon, Ash Meadows

Salix gooddingii Native, possibly cultivated

OVP, PU, NSP, C, PN, WS

Sauraceae (Lizard's Tail)

Anemopsis californica Native PU, S, OVP, NSP, C, PN, WS, K

Scrophulariacae (Snapdragon)

Castilleja angustifolia Native OVP, PU, NSP, C, PN, WS

Castilleja linariifolia Native S, OVP, PU, NSP, C, PN, WS

Mimulus guttatus Native S, K

Solanaceae (Nightshade)

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Datura wrightii Native PU, S, WS, OVP, NSP, C, K

Lycium andersonii Native OVP, PN, WS, PU, NSP, C, NNP, WA

Oasis Valley, Amargosa Desert, Indian Spring Valley

Nicotiana obtusifolia Native WS, OVP, PU, NSP, C, PN

Vitaceae (Grape)

Vitus arizonica Native NSP, PN, OVP, PU, C, WS

Zygophyllaceae (Caltrop)

Larrea tridentata Native PU, S, WS, OVP, NSP, C, PN, K

Amargosa Desert, Death Valley, Oasis Valley, Indian Spring

Valley, Pahrump Valley

Arecaceae (Palm)

Washingtonia filifera Introduced WS

Cyperaceae (Sedge)

Scirpus maritimus Native NSP, NNP

Juncaceae (Rush)

Juncus balticus Native OVP, NSP, PU, C, WS

Liliacae (Lily)

Calochortus flexuosus Native WS, OVP, NSP, PU, C, PN, K

Dichelostemma capitatum Native WS

Yucca schidigera Native OVP, NSP, PU, C

Poaceae

Achnatherum hymenoides Native NSP, C, OVP, PN, WS, K, PU

Distichlis spicata Native NSP, C, OVP, K, PU

Echinochloa crusgalli Introduced OVP

Leymus cinereus Native NSP, C, OVP, K, PU

Muhlenbergia asperifolia Native NSP, C

Phragmites australis Native PU, NSP, C, OVP, PN, WS, K

Sporobolus airoides Native NSP, OVP, PN

Typhaceae (Cattail)

Typha domingensis Native OVP, K, PU, NSP, C, WS, NNP

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3.1.1 Disturbance Regimes

Persistence of plant communities on the landscape requires adaption to the severity and frequency of disturbance. Knowledge of current and historic disturbance regimes is useful for understanding existing vegetation patterns as well as informing plans for future vegetation.

At AHME, fire regime contributes significantly to vegetation patterns. To gain insight into these patterns, an Ecological Niche Factor Analysis was used to model burning probability and severity within the refuge (Sunderman and Weisberg, in review). While fire regime can contribute to vegetation composition by selecting for resprouting plants, vegetation structure also contributes to burn probability. Dense heterogenous pre-fire vegetation (most often riparian forest and emergent wetlands) occurring near anthropogenic ignition sources has the greatest burn probability (Sunderman and Weisberg, in review). Burn severity is highest in homogenous vegetation types dominated by woody species, especially riparian forest. In contrast, desert upland vegetation types with low fuel connectivity and availability have low burn probability and low burn severity.

A fire history analysis was conducted for Ash Meadows, focusing on fires that occurred between 1980 and 2008 (Sunderman 2009). Use of remote sensing techniques successfully reconstructed nine of fifteen recorded wildfire events. Of the six fires omitted by the remote sensing technique, five fires were less than one acre in size. The analysis revealed that 12.3% of AHME burned and 19.8% of the burned area burned twice. Most of the burning within this time period was low-severity fire (93%), where as only 7% was high severity. Tendency of low severity fire is common in riparian areas of the western US, and many riparian plants resprout soon after fires due to adaptations for flood disturbance (Dwire and Kauffman 2003). At AHME, frequent, low severity fires may select for plants that are capable of resprouting.

Fire severity and frequency information as well as historic spatial patterns of fire on the refuge can be incorporated into revegetation efforts. Sunderman and Weisberg (In Review) caution that planting trees such as willow and ash may increase fire severity. However, willow and ash were historically abundant around springs (Threloff 1992). Planting to avoid creation of dense, homogenous stands of vegetation near human ignition sources will reduce the likelihood of frequent or severe fire, also reducing the establishment of weeds that thrive after fire.

3.2 Existing Conditions

The AHME vegetation map created by Bio-West (2010) and the construction footprints of each proposed restored channel alignment were intersected in ArcGIS 10 to assess which plant communities currently exist within each project area. The area examined was divided into three zones (Figure 3-3). One meter on either side of the channel was estimated as being water. A one meter buffer surrounding the water was expected to have saturated soils appropriate for wetland plants, and the recommended species list for replanting this zone was designed to favor native fish species (see two meter channel buffer in Figure 3-3). An additional

Carson Slough and Crystal Spring Revegetation | Final Report 15 eight meters on either side of the saturated zone was estimated as containing the construction footprint (see ten meter channel buffer in Figure 3-3).

Proposed target vegetation alliances are summarized with acreages for each channel alignment. These are the same vegetation alliances used in the Bio-West vegetation map, with the exception of the weed-dominated alliances. Cover of individual weedy species was estimated for each channel using the same method as above.

Each vegetation alliance was checked on NatureServe (accessed June 30, 2009) to identify the plants commonly found within the alliance. These commonly associated plants were cross-referenced with a plant list created by Otis Bay Ecological Consultants for Ash Meadows, as well as the current list for the AHME that has been updated by Bio-West (2010), to determine which species would be acceptable for use in revegetation efforts (Table 3.2).

3.3 Desired Future Conditions

Desired future conditions are long-term project goals that are initiated by revegetation of project areas. Planting recommendations are based upon existing plant communities, with some exceptions where plant communities are non-native (e.g., Tamarix Semi-Natural Temporarily Flooded Shrubland Alliance) or undesirable (Non-native Helianthus) (Table 3.2).

Proposed replacement plant communities for sites dominated by non-native species are suggested based upon disturbance and environmental conditions as well as an ability to compete with weedy species.

The period of time required to attain these desired conditions varies by habitat type, and given the extreme growing conditions in the Mojave Desert, some areas may take decades to obtain climax stage canopy cover of native species. The relevance of ecological succession theory to desert systems is uncertain because plant distribution and dominance is influenced primarily by tolerance to harsh environments and less affected by biotic interactions such as competition (Webb et al. 2009). For example, communities dominated by Sueda moquinii are highly saline, and when disturbances occur, Sueda usually recolonizes the area (Thomas et al. 2004).

Succession in desert spring systems is even more poorly understood. Therefore, in most situations we recommend planting species that are desired in the long-term instead of planting early successional species that might eventually phase into desired plant communities.

Areas within close proximity to the restored channel alignments should have sufficient soil moisture to fully recover within a few years of planting. The size and maturity of initial plantings will affect the rate at which potential communities establish following revegetation efforts. Therefore, mesic riparian vegetation areas that are planted with 3-4” potted plants will likely provide enhanced habitat in as soon as a few years. All other areas should be planted with #1 size container plants (industry term; actual capacity is roughly 0.75 gallons) to improve success rates under more difficult growing conditions.

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Figure 3-3. Depiction of methods used for vegetation assessment. The e isting vegetation alliances within the -m and -m buffers around proposed channel restorations were determined using GIS and the Bio-West (2010) vegetation map.

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Table 3.2. Existing plant alliances and replacement species for restoration areas. The relative percent cover, recommended number of plants per acre, appropriate soil pH, and approximate cost of plant materials per acre are given. Planting densities are estimated based on cover at maturity for species. Three plant mixtures that are variations of existing alliances are recommended.

Alliance Name/Planting Mix Species Relative

Percent Cover Number Salinity

Tolerance Range of Soil pH Cost per acre

Atriplex canescens Shrubland $2,227.01

Achnatherum hymenoides 7 102 Low 6.6-8.6 $304.92

Aristida purpurea 7 102 Low 5.5-7.5 $304.92

Atriplex canescens 50 245 High 6.5-9.5 $735.08

Ephedra nevadensis 7 57 Moderate 7.0-8.5 $171.52

Grayia spinosa 10 82 High 6.5-9.0 $245.03

Kraschninnikova lanata 7 57 High 6.6-8.5 $171.52

Lycium pallidum 7 57 Low 7.0-8.5 $171.52

Psorothamnus fremontii 5 41 Unknown Unknown $122.51

Atriplex confertifolia Shrubland

$1,979.26

Ambrosia dumosa 5 41 Moderate 7.0-8.5 $122.51

Atriplex confertifolia 50 245 High 7.5-9.0 $735.08

Atriplex polycarpa 5 41 High 7.5-9.0 $122.51

Ephedra nevadensis 2 16 Moderate 7.0-8.5 $49.01

Eriogonum heermannii 1 15 Unknown 5.0-8.0 $43.56

Grayia spinosa 5 41 High 6.5-9.0 $122.51

Gutierrezia microcephala 2 16 Unknown 6.8-7.5 $49.01

Krascheninnikovia lanata 5 41 High 6.6-8.5 $122.51

Larrea tridentata 15 123 Unknown 7.0-8.5 $367.54

Lycium andersonii 5 41 Low 6.0-8.0 $122.51

Sarcobatus vermiculatus 5 41 High 7.5-8.5 $122.51

18 Otis Bay Ecological Consultants

Percent Cover Number Salinity

Tolerance Range of Soil pH Cost per acre

Atriplex confertifolia - Isocoma acradenia Shrubland

$2,450.25

Atriplex confertifolia 25 204 High 7.5-9.0 $612.56

Ephedra nevadensis 5 41 Moderate 7.0-8.5 $122.51

Eriogonum heermannii 5 41 Unknown 5.0-8.0 $122.51

Gutierrezia microcephala 5 41 Unknown 6.8-7.5 $122.51

Isocoma acradenia 25 204 Unknown Unknown $612.56

Larrea tridentata 5 41 Unknown 7.0-8.5 $122.51

Lycium andersonii 5 41 Low 6.0-8.0 $122.51

Atriplex lentiformis Shrubland $1,976.54

Atriplex canescens 5 41 High 6.5-9.5 $122.51

Atriplex lentiformis 50 245 High 7.0-10 $735.08

Distichlis spicata 10 145 High 6.4-10 $261.36

Hymenoclea salsola 5 41 Unknown Unknown $122.51

Isocoma acradenia 5 41 Unknown Unknown $122.51

Larrea tridentata 15 123 Unknown 7.0-8.5 $367.54

Prosopis glandulosa 5 41 Low 7.0-8.5 $122.51

Carson Slough and Crystal Spring Revegetation | Final Report 19

Percent Cover Number Salinity

Tolerance Range of

Atriplex parryi Shrubland $2,227.01

Achnatherum hymenoides 7 102 Low 6.6-8.6 $304.92

Aristida purpurea 7 102 Low 5.5-7.5 $304.92

Atriplex parryi 50 245 High Unknown $735.08

Ephedra nevadensis 7 57 Moderate 7.0-8.5 $171.52

Grayia spinosa 10 82 High 6.5-9.0 $245.03

Kraschninnikova lanata 7 57 High 6.6-8.5 $171.52

Lycium pallidum 7 57 Low 7.0-8.5 $171.52

Psorothamnus sp. (fremontii) 5 41 Unknown Unknown $122.51

Baccharis emoryi Intermittently Flooded

$2,129

Baccharis emoryi 60 245 Moderate 6.0-8.5 $735.08

Distichlis spicata 10 145 High 6.4-10 $261.36

Juncus balticus 10 146 Moderate 6.0-9.0 $261.36

Sporobolus airoides 20 290 High 6.6-9.0 $871.20

Chrysothamnus albidus

$1,606.28

Aristida purpurea 10 145 Low 5.5-7.5 $435.60

Chrysothamnus albidus 80 245 Unknown Unknown $735.08

Poa secunda 10 145 Low 6.5-8.2 $435.60

20 Otis Bay Ecological Consultants

Percent Cover Number Salinity

Tolerance Range of Soil pH Cost per acre

Distichlis spicata

$2,570.04

Distichlis spicata 55 436 High 5.3-6.8 $784.08

Hordeum jubatum 5 73 High 5.0-7.2 $130.68

Iva axillaris 5 73 High Unknown $217.80

Juncus balticus 5 73 Moderate 6.0-9.0 $130.68

Muhlenbergia asperifolia 15 218 High 6.0-8.4 $653.40

Sporobolus airoides 15 218 High 6.6-9.0 $653.40

Distichlis spicata mixture $2,580.93

Distichlis spicata 50 436 High 6.4-10 $784.08

Muhlenbergia asperifolia 15 218 High 6.0-8.4 $653.40

Atriplex canescens 10 82 High 6.5-9.5 $245.03

Atriplex confertifolia 10 82 High 7.5-9.0 $245.03

Ericameria nauseosa

$2,480.20

Achnatherum hymenoides 10 145 Low 6.6-8.6 $435.60

Atriplex canescens 10 82 High 6.5-9.5 $245.03

Distichlis spicata 10 145 High 5.3-6.8 $261.36

Ericameria nauseosa 45 245 Unknown 7.5-8.7 $735.08

Psorothamnus fremontii 5 41 Unknown Unknown $122.51

Sporobolus airoides 10 145 High 6.6-9.0 $435.60

Carson Slough and Crystal Spring Revegetation | Final Report 21

Percent Cover Number Salinity

Tolerance Range of

Fraxinus velutina-Sporobolus airoides Woodland

$10,534.089, 411.53

Datura wrightii 5 41 Unknown 6.1-7.8 $122.51

Ericameria nauseosa 5 41 Unknown 7.5-8.7 $122.51

Fraxinus velutina 50 245 Low 5.8-7.5 $8,820.90

Distichlis spicata 10 145 High 5.3-6.8 $261.36

Sporobolus airoides 30 435 High 6.6-9.0 $1206.80

Isocoma acradenia Shrubland Alliance

$2,450.25

Atriplex confertifolia 10 82 High 7.5-9.0 $245.03

Ephedra nevadensis 5 41 Moderate 7.0-8.5 $122.51

Eriogonum heermannii 5 41 Unknown 5.0-8.0 $122.51

Isocoma acradenia 40 327 Unknown Unknown $980.10

Larrea tridentata 5 41 Unknown 7.0-8.5 $122.51

Lycium andersonii 5 41 Unknown 6.0-8.0 $122.51

22 Otis Bay Ecological Consultants

Percent Cover Number Salinity

Tolerance Range of Soil pH Cost per acre

Juncus arcticus Seasonally Flooded

$2,613.60

Carex praegracilis 25 363 Low 5.3-6.8 $653.40

Eleocharis rostellata 25 363 Moderate 6.0-8.0 $653.40

Juncus arcticus 5 73 Moderate 6.0-9.0 $130.68

Schoenoplectus americanus 15 218 Moderate 5.9-7.2 $392.04

Schoenoplectus maritimus 15 218 High 4.0-7.0 $392.04

Schoenoplectus robustus 15 218 High 6.4-8.4 $392.04

Prosopis glandulosa

$2,289.62

Acacia greggii 3 25 None 6.5-8.5 $73.51

Allenrolfea occidentalis 1 8 High 7.3-8.3 $24.50

Ambrosia spp. 2 16 Moderate 7.0-8.5 $49.01

Atriplex canescens 2 16 High 6.5-9.5 $49.01

Atriplex polycarpa 1 8 High 7.5-9.0 $24.50

Croton californicus 1 15 High 6.0-8.0 $43.56

Distichlis spicata 15 218 High 6.4-10 $392.04

Gutierrezia microcephala 3 25 Unknown 6.8-7.5 $73.51

Isocoma acradenia 2 16 Unknown Unknown $49.01

Krascheninnikovia lanata 2 16 High 6.6-8.5 $49.01

Larrea tridentata 2 16 Unknown 7.0-8.5 $49.01

Prosopis glandulosa 50 245 Low 7.0-8.5 $735.08

Suaeda moquinii 1 8 High 7.0-8.0 $24.50

Carson Slough and Crystal Spring Revegetation | Final Report 23

Percent Cover Number Salinity

Tolerance Range of Soil pH Cost per acre

Prosopis pubescens Woodland

$2,428.47

Atriplex canescens 1 8 High 6.5-9.5 $24.50

Atriplex polycarpa 2 16 High 7.5-9.0 $49.01

Baccharis emoryi 10 82 Moderate 6.0-8.5 $245.03

Distichlis spicata 20 290 High 6.4-10 $522.72

Isocoma acradenia 5 41 Unknown Unknown $122.51

Prosopis glandulosa 10 82 Low 7.0-8.5 $245.03

Prosopis pubescens 40 245 High 7.5-9.0 $735.08

Sporobolus airoides 10 145 High 6.6-9.0 $435.60

Suaeda moquinii 2 16 High 7.0-8.0 $49.01

Schoenoplectus americanus Semipermanently Flooded Herbaceous

$1,568.16

Schoenoplectus americanus 50 436 Moderate 5.9-7.2 $784.08

Juncus arcticus 25 218 Moderate 6.0-9.0 $392.04

Eleocharis rostellata 25 218 Moderate 6.0-8.0 $392.04

Sporobolus airoides

Herbaceous

$1,796.85

Allenrolfea occidentalis 1 8 High 7.3-8.3 $24.50

Atriplex lentiformis 1 8 High 6.5-9.5 $24.50

Atriplex canescens 1 8 High 7.0-10 $24.50

Distichlis spicata 5 73 High 6.4-10 $130.68

Poa secunda 6 87 Low 6.5-8.2 $261.36

24 Otis Bay Ecological Consultants

Percent Cover Number Salinity

Tolerance Range of

Sporobolus airoides 85 436 High 6.6-9.0 $1,306.80

Suaeda moquinii 1 8 High 7.0-8.0 $24.50

Suaeda moquinii

$2,096.33

Atriplex canescens 5 41 High 6.5-9.5 $122.51

Allenrolfea occidentalis 5 41 High 7.3-8.3 $122.51

Suaeda moquinii 60 245 High 7.0-8.0 $735.08

Sporobolus airoides 20 290 High 6.6-9.0 $871.20

Multi-Alliance mixture $2,495.99

DISP_IFH 40

See Association

$1,028.02

JUAR2_SFL 40

$1,045.44

PRPU_WD 10

$242.85

SPAI_IFH 10

$179.69

Carson Slough and Crystal Spring Revegetation | Final Report 25

4 PHASES OF WETLAND REVEGETATION

Revegetation efforts will be broken into six phases: 1) plant propagation, 2) plant material salvage, 3) weed treatment and removal, 4) soil surface preparation, 5) planting and installation of irrigation, and

6) monitoring and follow-up weed treatment.

Due to the time necessary for propagation of many plants recommended for revegetation (Table 4.1), plant propagation should be the first consideration in a restoration project. Some plants may need to be grown from seed. Other plant materials can be salvaged prior to, during, or after the initial restoration/construction phase. Initial weed removal efforts such as mowing or spraying should be completed prior to construction activities. Preliminary weed removal will reduce competition with established native species. If necessary, mechanical removal can be completed as part of the initial restoration/construction phase. Disturbance resulting from weed removal will not stress planted species if weeds are removed prior to planting.

Soil surface preparation will typically occur in the finishing/grading/completion phase of construction.

Collection and planting of salvage material should occur in late fall, winter, or early spring, when evapotranspiration rates are low, to minimize stress to transplanted individuals (Anderson and Ostler 2002). Plants should only be planted where sufficient soil moisture is present. Salvage material should be firmly pressed into the cleared soil surface and watered thoroughly. Supplemental watering should be used to minimize stress and encourage deep root growth of transplants. Plants should be irrigated throughout the growing season and into the summer. At the end of the growing season, irrigation should be slowly reduced. Irrigation should cease entirely when plants are determined to be well-established by an experienced plant ecologist.

The final restoration phase includes monitoring and subsequent weed treatments. Monitoring for weed resprouting and establishment should begin the month after treatment and continue monthly through the next several growing seasons. If follow-up herbicide treatments are applied, no additional control measures should be implementedfor at least one growing season. This time-period allows herbicides to take full effect while minimizing additional disturbances that could encourage re-sprouting. Some species, such as tamarisk, should not be treated again for two years to promote maximum herbicide effectiveness (Shafroth et al. 2010). If plants are disturbed before herbicides have had full time to take effect, it is recommended that herbicides be re-applied. Monitoring sites regularly will enable staff to make adjustments to each phase before minor problems compound and compromise revegetation efforts.

4.1 Plant Propagation

Native plant material for revegatation efforts may be introduced as salvaged plant material, hardwood cuttings, seed, or containerized plant material. The preferred method will differ depending on species and revegetation location (Table 4.1). Salvaged plant material is removed as a whole plant and planted in containers or directly at the revegetation site. Anemopsis, Carex, and Juncus species are particularly

26 Otis Bay Ecological Consultants suitable for this treatment as are any other rhizomatous species. Trees that would otherwise be removed by construction activities may be transplanted as salvaged material.

Hardwood cuttings are taken from the parent plant during the dormant period of late autumn to early spring and planted before bud break in the spring. These dormant cuttings may be stored at temperatures near freezing for a year or more. The cutting is a clone of the parent plant; therefore, cuttings should be collected from many parent plants to increase genetic diversity on the revegetation site. Although the Refuge does not have plans to plant additional willows at this time, Populus and Salix species can be propagated easily using this method should such plants become desired in the future. Hardwood cuttings from one-half inch to four inches or more in diameter will quickly root in springtime if moisture is available. Cuttings should be long enough to reach available soil moisture when planted, leaving at least one node above the soil surface for vegetative growth. Hardwood cuttings may be planted directly at the revegetation site or rooted in containers and then planted.

‘Seed dormancy’ is the term for viable seed that does not germinate even when placed in suitable conditions. Dormancy prevents the plant embryo from germinating at the wrong time of the year.

Seed dormancy can be physical, such as a hard seed coat in Prosopis spp., physiological, such as chemical inhibitors in Rosa spp., or a combination of both types of dormancy (MacDonald 1986). Seed should be collected locally in the wild. Collecting local seed has the advantage of obtaining local genotypes more suited to the revegetation location, but the disadvantage of the necessity for seed cleaning. Seed must be cleaned of any fleshy covering, husks, pods, bristles, or awns prior to seeding, as these structures can promote decay, may contain inhibitors to germination, and can clog seeding equipment.

Direct seeding by hand or with a drill-seeder is the method of applying live seed to a prepared seedbed. Preparation could include soil amendment, invasive species treatment, and plowing, disking, chaining, or otherwise creating micro-topography for the applied seed. Direct seeding in the fall allows the seed to utilize winter and early spring soil moisture and usually breaks any seed dormancy through imbibition of water and repeated freeze/thaw cycles. Graminoids are often successfully revegetated in this manner.

Containerized plant material can be grown from seeds, cuttings, or salvaged material. A containerized plant has the advantage of balanced root and vegetative growth, allowing for quicker establishment and therefore suppressing invading species. Supplemental water is usually necessary for the first growing season. If seed must be collected, the total time to produce a containerized plant for outplanting may take two to three years, depending on species and propagation system. If seed is available, this time period can be reduced to one year for some species (Landis and Simonich 1983).

Carson Slough and Crystal Spring Revegetation | Final Report 27

Table 4.1. Desired plants, preferred revegetation method, and propagation details. * indicates plants that are not currently on the planting list.

Scientific Name Common

Name Habitat Proposed method of re-introduction (plant / salvage)

Time needed to grow (blank=1 year)

Notes

Large Shade Trees

Fraxinus velutina velvet ash Riparian woodland

Plant 1-2 years Propagate from seed; collect in fall; sow in fall for natural stratification

Salix gooddingii* Goodding’s willow

Riparian woodland

Plant 0 -6 months

Propagate from hardwood cutting in dormant season;

plant cuttings before bud break

Shrubs Acacia greggii catclaw acacia Xeroriparian Plant Propagate from seed; collect pods when they begin to split;

scarification required

Allenrolfea occidentalis iodinebush Upland Plant Propagate from seed; collect Nov.-Dec. when jointed stems at branch ends are brown;

sow in winter

Ambrosia dumosa white bursage

Upland Plant Propagate from seed; leach seed in water for 24 hrs.

Amphipappus fremontii

Fremont’s chaffbush

Upland Plant

Atriplex canescens fourwing saltbush

Upland Plant 6-12 months

Propagate from seed; collect in fall when golden and papery; leach in water 24 hours, may also benefit from 4 hour soak in 3% hydrogen peroxide; stratify seeds at 3 to 5 C for 4 weeks

Atriplex confertifolia shadscale saltbush

Upland Plant Propagate from seed; collect in fall; leach in running water 24 hours

Atriplex lentiformis quailbush Floodplains, washes

Plant 6 months Propagate from seed; collect in fall; leach in water 24 hours

Atriplex parryi Parry’s saltbush

Atriplex polycarpa cattle saltbush

Upland Plant 6 months Propagate from seed; collect in fall when seeds turn hard;

leach in water 24 hours

Baccharis emoryi Emory’s baccharis

Riparian Plant 6 months Propagate from seed or semi-hardwood cuttings with 3000 ppm IBA

28 Otis Bay Ecological Consultants

Scientific Name Common Name

Habitat Proposed method of re-introduction (plant / salvage)

Time needed to grow (blank=1 year)

Notes

Chrysothamnus albidus whiteflower rabbitbrush

Upland Plant Propagate from seed

Croton californicus California croton

Upland Plant Propagate from seed; mature seed brown with tan spots;

leach in water 24 hours and cold stratify for one month

Encelia farinosa brittlebush Upland Plant 6 months Propagate from seed; collect in late spring; can be directly sown

Encelia virginensis Virgin River brittlebush

Upland Plant 6 months

Ephedra nevadensis

Mormon tea Upland Plant Propagate from seed, soak in 1:4 water bleach solution 1-3 hours, then leach in water 24 hours before planting

Ericameria nauseosa rubber rabbitbrush

Upland Plant Propagate from seed;

germinates at warm temp.

Eriogonum heermannii

Heermann’s Buckwheat

Upland Plant

Grayia spinosa spiny hopsage

Propagate from seed; collect in spring; can be directly sown

Gutierrezia microcephala threadleaf snakeweed

Upland Plant

Hymenoclea salsola burrobush Upland Plant Propagate from seed; collect in summer; leach in water 4 hours before planting

Isocoma acradenia alkali goldenbush

Upland Plant Propagate from seed; collect in Oct./Nov. when seeds look fluffy; directly sow and cover with thin layer of soil

Krameria erecta littleleaf ratany

Upland Plant Propagate from seed; collect in late summer/fall

Krameria grayi white ratany Upland Plant

Krascheninnikovia lanata winterfat Upland Plant Propagate from seed; collect in fall; chilling at 40 F for 14 days may improve germination; directly sow no deeper than . 5”

Larrea tridentata creosote Upland Plant Propagate from seed; collect in late spring when pods begin to split open; leach in water 48 hours before planting

Carson Slough and Crystal Spring Revegetation | Final Report 29

Habitat Proposed method of re-introduction (plant / salvage)

Time needed to grow (blank=1 year)

Notes

Lycium andersonii wolfberry Washes Plant Propagate from seed; collect in June when berries have fully matured, leach in water 24 hours before planting

Lycium pallidum pale desert-thorn

Upland

Pluchea sericea arrowweed Riparian woodland/ Mesic shrubland

Plant Propagate from seed, or cuttings in June/July from young vigorous stems

Prosopis glandulosa honey mesquite

Xeroriparian Plant Propagate from seed; collect in fall when pods begin to split; scarification required;

plant in fall in well drained soil

Prosopis pubescens screwbean mesquite

Xeroriparian Plant Propagate from seed; collect in fall; scarification sometimes required; plant in well drained soil; germinate best with warm air/soil temp.

Psorothamnus fremontii

Fremont’s dalea

Upland Plant

Rhus trilobata* sumac Riparian woodland/ Mesic shrubland

Plant 6-12 months

Propagate from seed, root cutting or softwood cutting;

plant seed in fall/winter for natural stratification; cold stratify 40-60 days; aqueous extract of charred wood increases germination;

intolerant of crowding

Salazaria…