David R. Dreesen

Deep-planting techniques to establish riparian vegetation in arid and semiarid regions

Invasion by exotic woody species and disruption of natural hydrologic conditions require the restoration of native riparian plant communities along rivers and streams in the Southwest. Successful establishment of phreatophytic riparian plant species has been accomplished using deep-planting techniques that involve the immediate exploitation of capillary fringe moisture by the existing root system of nursery stock or the adventitious root system of a cutting. These techniques, which require minimal or no post-planting irrigation in arid and semiarid regions, include the planting of dormant pole cuttings, dormant whip cuttings, tallpots with long root systems, as well as long-stem nursery stock whose root crowns are deeply buried.

Deep-planting methods that require minimal or no irrigation to establish riparian trees and shrubs in the Southwest

During the past 20 years, the Los Lunas Plant Materials Center (LLPMC), USDA Natural Resources Conservation Service, has developed deep-planting techniques that require minimal or no follow-up irrigation to establish woody vegetation on disturbed riparian sites in the arid and semiarid Southwest. The use of these techniques results in minimal maintenance and high survival rates, which will reduce ultimate revegetation costs. Invasive exotic woody species, primarily saltcedar (Tamarix sp. L.) and Russian olive (Elaeagnus angustifolia L.), have been controlled on floodplain tracts totaling more than 13,750 ha (34,000 ac) along New Mexicos major rivers during the past five years by mechanical extraction or herbicide application (New Mexico Department of Agriculture 2005). Principal motives for these efforts include conserving groundwater, reducing wildfire potential, restoring wildlife habitat, and providing grazing or other beneficial uses. The alteration of surface and groundwater hydrology by flood control structures and flow regulation has encouraged the spread of invasive woody species (Stromberg et al. 2007) and has resulted in relatively deep water tables on many sites. The lack of overbank flood events on these rivers has perturbed normal ecosystem function and prevented the natural recruitment of native species comprising the gallery forest and its understory vegetation. The

Influence of Provenance on Ribes Cereum and Symphoricarpos Oreophilus Seed Germination in New Mexico Seed Sources 1

Mountain snowberry (Symphoricarpos oreophilus) and wax currant (Ribes cereum) are co-occurring shrub species found in ponderosa pine and mixed conifer forests in New Mexico. These species are candidate species for mined land reclamation because both occur in full sunlight and in the understory and are found on a wide range of edaphic conditions. Mountain snowberry seeds have both a scarification and a stratification requirement for germination, whereas wax currant seeds require only stratification treatment. Separate studies were conducted examining the influence of provenance, from within New Mexico, on conventional seed propagation protocols for each species. The wax currant study utilized eight seed sources and the mountain snowberry study utilized seven seed sources. Seed sources were selected to represent the latitudinal range of the species in New Mexico, and an elevational range at the most northerly latitude sampled. There was considerable variability among seed sources of both species in overall germination rates and response to treatment severity. In wax currant, the southernmost source did not benefit from stratification, but for all of the more northerly sources, germination was improved by stratification treatments. There was also considerable variability among mountain snowberry seed sources in response to scarification treatments, but no distinct latitudinal trends were apparent. Implications of these studies on selection pressure and restoration are discussed.

Propagating native Salicaceae for riparian restoration on the Hopi Reservation in Arizona

The USDA Forest Service, USDA Natural Resources Conservation Service (NRCS), and the Hopi Tribe Office of Range Management have been working together on native plant restoration projects in northeastern Arizona. The aggressive exotic plants, Russian-olive (Elaeagnus angustifolia L. [Elaeagnaceae]) and salt-cedar (Tamarix ramosissima Ledeb. [Tamaicaceae]), have invaded many wetland and riparian areas on the Hopi Reservation, excluding willows (Salix L.), cottonwoods (Populus L.), and other native plants. The tribe has been mechanically removing the invasives and has asked for help in propagating native species to plant in these project areas. Although much information is available on how to collect willows and cottonwoods and propagate them, some unique challenges exist on Hopi lands. Some species are common, while others are very rare and in some cases only a few individual plants exist. The scattered locations of streams, wetlands, and seeps must be considered during plant material collections to ensure that both genetic and sexual diversity are adequately represented. Another challenge is the determination of target plant stock types that are appropriate on the diverse hydrologic conditions on the various project sites. Collected plant materials were taken to the NRCS Plant Materials Center in Los Lunas, New Mexico, for both seed and vegetative propagation.

RESULTS OF SPECIES TRIALS ON LOW PH OVERBURDEN MATERIALS FOR MINE LAND RECLAMATION I

The Molycorp molybdenum mine in north-central New Mexico operated as an open pit mine from the mid 1960s to the early 1980s. The overburden piles generated during this operation are heterogeneous in respect to rock types containing neutral rock types as well as mixed volcanic rock types. The mixed volcanic rocks are highly weathered materials with low pH and high salinity resulting from pyrite oxidation. Undisturbed areas surrounding the mine site having similar mixed volcanic rock types as found in the overburden piles, support vegetation indicating there may be native plants in this climatic region which are adapted to low pH conditions and associated soluble constituents found in these materials. This study was set up to evaluate the survival of different native and exotic plant materials across a range of overburden materials found at the Molycorp site. Determining what species can survive on the different overburden materials is instrumental in implementing an effective reclamation program at the site. Two overburden rock types representing both the mixed volcanic rock types and the neutral rock types, were crushed and mixed to generate 4 different overburden materials. These materials ranged in pH from 2.7 to 4.4 and had electrical conductivities ranging from 1.9 to 3.6 ds/m. The overburden materials were placed into IS-gallon horticultural pots located at the Mora Research Center, Mora, N.M. The study used 164 cm 3 container transplants of the following 52 plant types: ten conifer species, 16 legume species, five species of forbs and sub-shrubs, and 21 shrub species. The study was initiated in June 1995 and survival evaluated in June 1996. Survival results for species are presented. When 70% survival and a vigor rating of good are used as the criteria for determining potential for a species to be used in the reclamation program 42 and 38 species would be suitable for the two overburden materials with the highest pH and lowest EC, respectively. In the substrate with the second lowest pH (3.3) and second highest EC (3.2 ds!m), 21 species or sources had greater than 70% survival. In the most acidic overburden having the highest EC (3.6 dslm), six coniferous tree species and three shrub species had greater than 70% survival. As an initial screening tool this study has provided information on species with potential for direct establishment on low pH «3.3), high Ee (>3.2 dslm) overburden.

INFLUENCE OF PISOLITHUS TINCTORIUS INOCULATION ON GREENHOUSE GROWTH AND FIRST-YEAR TRANSPLANT SURVIVAL OF CONIFER SEEDLINGS

Mycorrhizal fungi form a symbiotic association with the root systems of most higher plants. Mycorrhizae colonization of root systems is believed to improve tolerance to adverse soil conditions such as low pH or high salinity. Mined land reclamation may require transplanting seedlings onto harsh sites that may have low pHs, high salinity, low nutrient status, etc. The purpose of this study was to examine whether inoculation of conifer seedlings in the greenhouse with Pisolithus tinctorius would improve first year survival of seedlings transplanted onto overburden material at the Molycorp Questa Mine in northern New Mexico. Seedlings of Pinus ponderosa, P. edulis, P. strobiformis, P. flexilis, P. aristata, P. sylvestris, and P. nigra were used in this study. Subsets of each species were inoculated with Pisolithus tinctorius at either six or ten weeks after germination or not artificially inoculated. Seedlings were evaluated for growth response in the greenhouse after inoculation and before transplanting. Inoculation and growth media composition significantly impacted shoot height and caliper growth but responses were species-dependent and the magnitude of the differences between inoculated and non-inoculated seedlings were small. Seedlings were transplanted in August 1996 on a site at an elevation of 9,500 ft. and with substrate pH ranging from 3.5 to 4.0. The impact of inoculation with Pisolithus tinctorius on survival was variable by species. Only P. strobiformis had improved survival with inoculation (>20%). Additional