Showing papers on "Native plant published in 1997"

Rapid Assessment of Plant Diversity Patterns: A Methodology for Landscapes

Abstract: We present a rapid, cost-efficient methodology to link plantdiversity surveys from plots to landscapes using: (1) unbiasedsite selection based on remotely sensed information; (2) multi-scale field techniques to assess plant diversity; (3)mathematical models (species-area curves) to estimate thenumber of species in larger areas corrected for within-typeheterogeneity; and (4) mathematical techniques to estimatetotal species richness and patterns of plant diversity in alandscape. We demonstrate the methodology in a 754 ha studyarea in Rocky Mountain National Park, Colorado, U.S.A.,using four 0.025 ha and twenty-one 0.1 ha multi-scalevegetation plots. We recorded 330 plant species (∼1/3 thenumber of plants recorded in the 1074 km2 Park) in the2.2 ha area within the plots: this represents a samplingintensity of 0.29% of the 754 ha study site. We estimated 552plant species, about half the plant species recorded in the Park,in just 0.7% of the Park‘s area. We show how this rapid,cost-efficient methodology: (1) produces a rich informationbase on the patterns of native plant diversity and thedistribution of non-native plant species and keystoneecosystems; and (2) can be easily adapted for other nationaland state parks, national forests, wildlife refuges, and nature reserves.

The seed rain and seed bank of an adjacent native tallgrass prairie and old field

Abstract: The ability of a grassland to regenerate following disturbance depends on the presence of seeds of native plants and the ability of the seeds to germinate. To examine whether the presence or absence of plant propagules influences reestablishment of tallgrass prairie on abandoned agricultural lands, we sampled the seed rain and soil seed bank across a transition from native tallgrass prairie to unmanaged successional grassland (old field). The native prairie seed rain was seven times greater than that of the old field, richer in species (33 vs. 27), and more diverse (diversity index 0.96 vs. 0.73). In addition, the native tallgrass prairie seed bank was three times as dense as the old-field seed bank and contained the seeds of more species (23 vs. 19), but had a lower index than did the old field (0.81 vs. 1.08). One species, Sphenopholis obtusata, present in the prairie, was observed dispersing to the old-field plot, but was absent in the old-field plot; this observation suggests that at least some specie...

Plant succession and its optimization on tar-polluted coasts in the Arabian Gulf region

Abstract: Summary Coastal ecosystems in the Arabian Gulf region are under increasing pressures from hostilities and other developmental activities; the region has a long history of crude-oil pollution. Because of the high ambient temperature, oil deposited along the coastline or inland evaporates, leaving a semi-solid tar. In Qatar, to clean up the polluted sites, the deposited tar is stripped off and dumped in the coastal marshes as confluent dome-shaped piles. Flowering plant colonization of tar-piles is described here as a chronosequence, ranging in age from 2 to 14 years. The successional patterns in vegetation, seed bank, species diversity and plant growth were predicted from tarpile disturbances with different ages and tar content. The success of natural plant colonization and the establishment of plant communities on the tar-pile disturbances depend upon: (1) age of the tar-pile disturbances, (2) tar content of the piles and soil physicochemical properties, (3) soil moisture content, (4) structure of plant communities in the surrounding landscape, (5) size of the disposal sites and the method of dumping, and (6) prevailing environmental conditions. A management and restoration framework is proposed to optimize the natural recolonization of tarpiles. To retain these ecosystems in a self-sustaining state, some native plant species might be used including: Aeloropus lagopoides, Aizoon canariense, Anabasis setifera, Fagonia indica, Mesembryanthemum nodiflorum, Reichardia tingitana, Salsola imbricata, Suaeda aegyptiaca, Senecio glaucus, Sporobolus arabicus, Zygophyllum quatarense, and Zygophyllum simplex. To clarify the biological and chemical aspects of the problem, further research on the chemistry of tar-polluted soil and its vegetation in relation to the food web is needed.

Propagation of native plants for restoration projects in the Southwestern U.S.: preliminary investigations

Abstract: Seed treatments to enhance germination capacity of a variety of native tree. shrub. forb. and grass species are reported. Scarification methods including hot water immersion (HW). mechanical scarification (MS). tumble scarification (TS), proximal end cuts (PEC), and sodium hypochlorite (SH) have been tested: Psorothamnus fremontii (HW. TS). Ceanothus integerrimus (HW). Ceanothus sanguineus (HW). Rhus g/abra (HW). Pte/ea trifoliata (PEG of seed separated by size and color). Rubus strigosus (SH), Oryzopsis hymenoides (TS), Co/eogyne ramosissima (TS). and a variety of native woody and herbaceous perennial legume species (HW. TS. MS). Gibberellic acid treatments were examined to overcome endo-dormancy of A/nus tenuifo/ia. A. ob/ongifolia, Rubus strigosus, and Oryzopsis hymenoides. Vegetative propagation methods investigated include mound layering of Platanus wrightii, root propagation of Populus tremu/oides. and pole plantings of riparian understory species (Amorpha fruticosa, Baccharis glutinosa, Forestiera neomexicana. and Chilopsis Iinearis).

Post-fire herbicide sprays enhance native plant diversity

Abstract: Following catastrophic fire, broad-spectrum herbicides such as hexazinone are often used to control shrubs and forbs that compete with planted conifers. This practice encourages rapid growth and reduces mortality of conifers. Although the initial effect is to reduce native plant species richness, recovery is rapid and plant diversity exceeds that in untreated areas within 8 years of application. Success of native forb and grass species in herbicide-treated areas appears to be due to early suppression of otherwise dominant shrubs.

Restoration of disturbances in Yellowstone and Glacier National Parks

Abstract: Revegetation, reclamation, and restoration—all imply the reestablishment of plant cover on a disturbed site, but if taken literally may imply three levels or intensities of site mitigation. ‘Revegetation’ is simply the re-establishment of a plant cover, often a monoculture of an introduced plant species. Although relatively inexpensive, revegetation may not offer permanence or ecological stability. ‘Reclamation’ has been defined historically as the process of returning disturbed land to a condition that approximates the original site conditions and is habitable by the same or similar plants and animals which existed on the site before disturbance (Redente et. al 1994). ‘Restoration’ strives to emulate the structure, function, diversity, and dynamics of a specific ecosystem. Topsoil salvage can preserve the soil biota along with viable propagules of indigenous plant materials. By utilizing native indigenous plant material (seed, cuttings, transplants), the genetic integrity and diversity of the native plant communities will be maintained. Even with soil salvage and the use of native indigenous plant materials, restoration must not be interpreted as a discrete event, but rather as an ongoing process involving the reestablishment of nutrient cycling, plant succession, and plant community dynamics. The U.S …

Breeding of Cold Hardy Woody Landscape Plants

Abstract: Cold winters, hot summers, drought, insects, and diseases take their toll on landscape plants, especially those growing in difficult urban situations. Due to widespread concern about global warming and its hazardous effects on the environment, many efforts are underway to encourage planting of trees and other landscape plants to help alleviate the greenhouse effect. For these planting efforts to be most successful, we have a pressing need for a much broader choice of well adapted cultivars. Many of our native plants and currently available introduced plants are not well adapted to the harsh conditions we’ve created in our cities. Compacted soil, poor fertility, pollution, and heat plus drought from the acres of concrete and asphalt are very different than the conditions under which these plants evolved. As a result, many trees and shrubs planted in the cities fail to survive to produce the desired effects. If we are to keep our cities green, tougher plants which can survive this man-made environment must be developed.

Management of Cape-ivy (Delairea odorata) in the Golden Gate National Recreation Area

Abstract: The objective of this paper is to provide an overview of our Cape -ivy (Delairea odorata, formerly Germanivy, Senecio mikanoides) control program at the Golden Gate National Recreation Area (GGNRA). Like many preserves, lands of the GGNRA have an extensive history of human induced ecological change, now largely influenced by the introduction, establishment and spread of non -native plants and animals. Known as biological invasions, these introductions can affect ecosystem processes and accelerate the loss of biological diversity (Vitousek et al. 1996, Mooney et al. 1986). Park Service resource managers charged with "protecting and preserving all species of native flora and fauna within all management areas" are overwhelmed by the enormity of the task of managing biological invasions, particularly when so few ecological st udies have been conducted to quantify threats. Without this basic information it is virtually impossible to identify which invasive species have the greatest impact on a given system and prioritize management decisions. Consideration must also be given t o the extent and rate of spread, as well as the feasibility and cost of controlling invasive plant species. Taking these complex factors into account, we have begun a park -wide Cape-ivy containment program that also includes an adjacent park, the Point Reyes National Seashore. This paper provides a systematic approach to the control of Cape -ivy consisting of a variety of containment and removal methods which are being incorporated into existing community volunteer programs. Our primary goal is to stop th e park-wide expansion of Cape-ivy and contribute to the science of conservation biology

Ecotypes of Native Species: How Local is Local in Restoration Plantings?

Abstract: The growing knowledge of the threats posed by exotic species to native biodiversity has generated a great deal of interest in planting native species and restoring native plant habitat. In addition, planting native species is often an integral part of exotic plant eradication efforts. By planting native species the hope is that these plants will take over the space formerly occupied by the exotics and thereby help reduce the chances of unwanted recolonization by the latter. However, planting native species can bring a new set of "exotic vs. native" issues. If a seed source is used that evolved in a different region, in association with different climate and soil types, it can be argued that such a planted population is in reality no more "native" to that site than an exotic species would be. A basis for this argument is that extensive genetic differences are found among populations of most native species. These genetic differences can be caused by natural selection acting across a diverse array of environments, or by genetic drift, due to small population size and lack of genetic mixing (gene flow) among populations, or a combination of both. Populations that differ as a result of natural selection are known as "ecotypes" and are often best adapted to the local environmental conditions. Thus, if non-local seed sources are used for a project, the plants may not be well adapted. This can not only lead to failure of the plants to persist (see discussion in Handel et al. 1994), but can also result in genetic contamination of existing local populations of the species (Millar and Libby 1989, Libby and Rodrigues 1992, Knapp and Rice 1994, Knapp and Dyer 1997). Only recently, the importance of genetic variation within the species has been widely appreciated by restorationists (Padgett and Crow 1994). An example of this shift in thinking is that agencies such as the U.S. Forest Service (USFS) and the Bureau of Land Management (BLM) now require seed of native plants for projects on Federal lands to originate from "genetically local sources." However, the lack of information on patterns of natural genetic variation in many native species makes defining "local" difficult. The USFS uses seed zones based on geographic and genetic information to dictate regions of transfer for commercially harvested conifer species (Buck et al. 1970). Rudimentary rules have been attempted for other species for which only limited, if any, genetic information is available. For example, Linhart (1995) suggested that seed of herbaceaous species be collected not more than 100 meters away, and seed of woody species not more than 1 km away. However, it is not yet known for most native plant species over what geographic ranges seed can be successfully transferred and grown over the long term, or to what extent local populations are genetically superior to non-local populations. In addition, experiments have not yet been carried out to determine what happens to seed from non-local plants. Do these plants eventually die" Can they spread like weedy species, and can these non-local genotypes contaminate local populations of the same native species? These are some of the questions we sought to answer when we initiated our research on patterns of genetic variation in native grass species. Our objective in this paper is to briefly summarize some of our findings to date and to explain the relevance of these findings to native plant restoration.

Eucalyptus Removal on Angel Island

Abstract: As part of its mission, California State Parks is required to "preserve the state's extraordinary biological diversity, protecting its most valued natural and cultural resources." Sometimes eucalyptus trees have historical significance and must be preserved, but in settings where natural values predominate, removal is clearly called for. The case for removal was strong on Angel Island but the proje ct proved to be controversial. Eucalyptus removal was finally completed in 1996, approximately ten years after planning for the project began. Active restoration work continues to date on the sites previously occupied by these trees. Impacts of Eucalyptus By the mid 1980s, when plans to control eucalyptus on the island were being developed, there were approximately 86 acres of bluegum eucalyptus, Eucalyptus globulus, in the park. Small groves, which totaled only 24 acres, had been planted by the milita ry. These original groves had expanded over time as native plant communities were invaded by new seedlings. Native plants and the wildlife habitat that they provided disappeared as eucalyptus trees began to dominate large portions of the landscape. Coas tal scrub and grassland were primarily lost but areas of mixed evergreen forest were also affected. In addition, the bluegum species of eucalyptus created an extreme fire hazard compared to the native plant -communities of the island. The fire danger prod uced by eucalyptus was dramatically observed during the Oakland Hills fire of 1991. A wildfire in bluegum eucalyptus burns with tremendous intensity, and under severe weather conditions (e.g. hot and windy) can produce drifting burning material which has great potential to ignite spot fires. Because their stringy bark is carried away while burning, eucalyptus forests are considered the worst in the world for producing this type of fire spread. While the native plant communities of the island would be affected by wildfire, their general health would not be jeopardized. Only the visual impacts of charred trees in a park with high visitor use would be detrimental. The historic structures on the island, however, could easily be lost due to the hazard posed by eucalyptus trees. Public Reaction

Desirables and weeds for roadside management--a northern rocky mountain catalogue

Abstract: The roadside flora of Montana and adjacent North Dakota were examined with the objective of identifying common plants which might be used in new plantings (desirables) or managed against (weeds). Of 211 species found, 50 were common in at least one environmental type. Of these, 29 were natives and 21 were exotics. Great caution is recommended with broadening the dispersal of exotics. Tables in Part I of this report list both species performing well in major environmental types and those sensitive to particular factors. Two tables (6 and 7) identify plants - desirables and exotics - likely to succeed in the five environmental zones (ETs) most Montana highways traverse. The ETs are identified by the natural vegetation that would occupy them "at climax" and a map locates those zones. The ETs are dry grassland environments, moist grassland environments which are warmer or cooler, low forest environments, and high forest environments. Table 6 is useful for selecting species for planting in a region. Table 7 indicates zones in which common exotics are most likely to spread from plantings into native vegetation. Table 8 summarizes the site preferences of the 50 species with respect to levels of ten environmental factors likely to influence them, rather than ET. The factors considered relate to water availability (precipitation, soil water holding capacity, soil sand/clay content), temperature (July average, slope, and aspect), fertility (organic matter and pH) and salinity. Table 8 will be especially useful in selecting species for extreme sites. Part II of the report complements Tables 6, 7, and 8 by characterizing species rather than environments. It tells how each species behaves: ETs it grows in, factor extremes it tolerates, the form it will take, and its tendency to invade.

'Umatilla' snow buckwheat for rangeland restoration in the interior Pacific Northwest

Abstract: Native plants are generally considered the best option for plant materials to restore productivity and diversity to degraded rangelands (McArthur 1988). It is difficult to find native plants capable of becoming established from seed in dense stands of introduced annual species such as cheatgrass. It has been easier to import species such as crested wheatgrass to restore perennial grasses on degraded rangelands. Although successful, such revegetation has not been without drawbacks. Establishment of large areas of a single plant species lowers vegetative diversity and may be aesthetically less desirable than a diverse community of native species. Monocultures also tend to have insect and disease problems that are less prevalent in plant communities with greater diversity.

Threatened and Endangered Species Survey for Patrick Air Force Base, Florida

Abstract: A review of previous environmental work conducted at Patrick Air Force Base (PAFB) indicated that several threatened, endangered, or species of special concern occurred or had the potential to occur there. This study was implemented to collect more information on protected species at PAFB. A map of landcover types was prepared for PAFB using aerial photography, groundtruthing, and a geographic information system (GIS). Herbaceous vegetation was the most common vegetation type. The second most abundant vegetation type was disturbed shrubs/exotics. The beach and associated dune vegetation comprised 3.2% of the land area, but was the most extensive natural community within PAFB. A few isolated mangrove communities exist along the Banana River. Seventy-seven species of vascular plants occurred on the dunes, including four species listed by state agencies: spider lily (Hymenocallis latifolia), prickly pear cactus (Opuntia stricta), beach star (Remirea maritima), and inkberry (Scaevola plumien). Surveys of other habitats revealed eighty-four species of vascular plants including two state-listed species: spider lily and prickly pear cactus. Many of these areas are dominated by invasive, exotic species, particularly Brazilian pepper (Schinus terebinthifolius) and Australian pine (Casuarina equisetifolia), and native species of open or disturbed sites such as camphorweed (Heterotheca subaxillaris) and beardgrass (Andropogon spp.). Due to the isolation of PAFB from other natural areas, most exotic plant populations on the base are not an immediate threat to intact native plant communities. Dune habitat was surveyed for the southeastem beach mouse (Peromyscus polionotus niveiventris) by quarterly trapping along eight 100 m transects. No beach mice were found. The limited extent of dune habitat, its fragmented condition, and the isolation of PAFB from extant populations of the beach mouse probably accounts for its absence. Surveys of birds on PAFB found an avifauna characteristic of species that occur in the Indian River Lagoon system. Twenty-five species of waterbirds were observed during quarterly surveys on PAFB, including five species listed as species of special concern by the state of Florida: Snowy Egret (Egretta thula), Little Blue Heron (Egretta caerulea), Tricolored Heron (Egretta tricolo4, White Ibis (Eudocimus albus), and Brown Pelican (Pelecanus occidentalis). The Golf Course was used extensively by almost all species of waterbirds on PAFB. Twenty-two species of shorebirds were observed on PAFB. Although no listed species were observed, the potential exists for several protected species of shorebirds to use the beach at PAFB during some parts of the year. The Airfield runways and associated grass areas were important sites at PAFB for loafing and feeding for some shorebirds. Surveys of rooftop nesting by Least Terns (Stema antillarum) on PAFB found a large colony on a rooftop in the PAFB Industrial Area. This colony produced some independent young. Two rooftop Least Tern colonies reported from previous years were inactive during 1996. A small number of Black Skimmers (Rhynchops nigee attempted to nest at the Least Ten colony but were unsuccessful. Surveys for the gopher tortoise (Gopherus polyphemus) revealed burrows and tortoises only at the Waste Study Site; five burrows and three tortoises were observed. No Florida scrub lizards (Sceloporus woodi), eastern indigo snakes (Drymarchon corais couperl), or diamondback terrapins (Malademys terrapin terrapin) were observed. American alligators (Alligator mississippiensis) were observed on the Golf Course and using ditches, ponds, and areas along the Banana River. The amount of dune habitat could be expanded by not mowing areas adjacent to the dunes to allow dune species to colonize and expand. Planting dune species as part of the beach renourishment project will also increase this habitat. Exotic plants dominate several areas on the base and are used by threatened, endangered, and species of special concern. However, the use of native vegetation in landscaping projects throughout the base would improve habitat for wildlife, and invasive, exotic plants should not be used in any horticultural plantings. Water quality of ponds, ditches, and canals is important for waterbirds; it should be maintained and protected from contamination. Nesting Least Terns are sensitive to disturbance; rooftops used for nesting should be protected from disturbance. Monitoring of Least Tern and Black Skimmer nesting should be continued to determine what roofs are being used and whether nesting is successful. Furthermore, based on the large numbers of waterbirds observed on PAFB, continued monitoring of them is recommended.

Natural succession impeded by smooth brome (Bromus inermis) and intermediate wheatgrass (Agropyron intermedium) in an abandoned agricultural field

Abstract: In 1975, an abandoned agricultural field at Rocky Flats Environmental Technology Site (Site) that had been cultivated for more than 38 years, was seeded with smooth brome (Bromus inermis) and intermediate wheatgrass (Agropyron intermedium). Although these species are commonly planted in reclamation and roadside seed mixtures, few studies have documented their impact on the re-establishment of native plant communities. In 1994, species richness, cover, and biomass were sampled in the agricultural field and compared to the surrounding mixed-grass prairie at the Site. The agricultural field contained only 61 plant species (62% native), compared to 143 species (81% native) in the surrounding mixed-grass prairie. Community similarity based on species presence/absence was 0.47 (Sorensen coefficient of similarity). Basal vegetative cover was 11.2% in the agricultural field and 29.1% in the mixed-grass prairie. Smooth brome and intermediate wheatgrass accounted for 93% of the relative foliar cover and 96% of the biomass in the agricultural field. The aggressive nature of these two planted species has impeded the natural succession of the agricultural field to a more native prairie community. Studies of natural succession on abandoned fields and roads in northeastern Colorado have indicated that if left alone, fields would return to their native climax state in approximately 50 years and would be approaching their native state after 20--25 years. Based on the results of this study, this agricultural field may take more than 100 years to return to a native mixed-grass prairie state and it may never achieve a native state without human intervention.