Herbaceous Perennial Legume Research Articles

Herbage and Seed From Texan Native Perennial Herbaceous Legumes

Native seed mixes for rangeland seeding, prairie restoration, or cultivated pasture can benefit from a greater variety of forbs that more closely reflect the original vegetation of the southern Great Plains. Fifteen native, perennial herbaceous legumes were collected in central Texas and evaluated for herbage production, mineral content, and fiber concentration of established plants in research plots over 2 years. Downy milk-pea ( Galactia volubilis [L.] Britton) was productive, regardless of rainfall, whereas prairie acacia ( Acacia angustissima [Mill.] Kuntze var. hirta [Nutt.] B.L. Rob.) and Illinois bundle-flower ( Desmanthus illinoensis [Michx.] MacMill. Ex. B.L. Rob. & Fernald) out-yielded others in year 3 when rainfall was the greatest. Herbage crude protein averaged approximately 100 g·kg −1 for bush-clovers ( Lespedeza spp.) compared to bundle-flowers ( Desmanthus spp.), which exceeded 200 g·kg −1 ; the latter also was high in herbage phosphorus. Herbage neutral detergent fiber ranged from 300 to more than 500 g·kg −1 , acid detergent fiber ranged from 140 to 360 g·kg −1 , and acid detergent lignin ranged from 36 to 140 g·kg −1 , a wide range from which to select if animal nutrition is a primary criterion. Seed production was evaluated within a subset of 8 entries submitted to periodic herbage removal or left intact throughout the season. Three bundle-flowers yielded the greatest mass and seed number, but were negatively affected by harvest, unlike prairie acacia. Herbage and seed characteristics indicate there are promising perennial herbaceous legumes in the southern Great Plains that can be included in native seed mixes. Las mezclas de semillas nativas para la siembra de pastizales, restauración de praderas o pasturas cultivadas pueden beneficiarse de una gran variedad de hierbas que reflejan más cercanamente la vegetación original de las Grandes Planicies del sur. En la parte central de Texas se colectaron 15 leguminosas herbáceas perennes nativas y se evaluaron en dos años para ver su producción de forraje, contenido mineral y concentraciones de fibra de plantas establecidas en parcelas experimentales. “Downy milk-pea” ( Galactia volubilis [L.] Britton) fue productiva sin importar la precipitación, mientras que “Prairie acacia” ( Acacia angustissima [Mill.] Kuntze var. hirta [Nutt.] B.L. Rob.) e “Illinois bundle-flower” ( Desmanthus illinoensis [Michx.] MacMill. Ex. B.L. Rob. & Fernald) sobrepasaron en rendimiento a las otras especies en el tercer año, cuando se presentó la mayor precipitación. La proteína cruda del forraje promedió aproximadamente 100 g·kg −1 en el “Bush-clovers” ( Lespedeza spp.) en comparación con el “Bundle-flowers” ( Desmanthus spp.) que excedió los 200 g·kg −1 , esta última también fue alta en fósforo. La fibra neutro detergente del forraje varió de 300 a más de 500 g·kg −1 , la fibra ácido detergente de 140 a 360 g·kg −1 , y la lignina ácido detergente de 36 a 140 g·kg −1 , un rango amplio del cual seleccionar si la nutrición del animal es el principal criterio. La producción de semilla fue evaluada dentro de un subgrupo de 8 entradas sujetas a remoción periódica del forraje o con la hoja intacta a lo largo de la estación. Tres “Bundle-flowers” rindieron la mayor masa y número de semillas, pero fueron negativamente afectadas por la cosecha de forraje, menos la “Prairie acacia.” Las características del forraje y la semilla indican que hay leguminosas herbáceas perennes prometedoras en las Grandes Planicies de sur que pueden ser incluidas en las mezclas de semillas nativas.

Evaluation of perennial herbaceous legumes with different phosphorus sources and levels in a Brazilian Ultisol

AbstractThis study was carried out under field conditions with the aim of evaluating the period of time necessary for soil cover, dry matter production and accumulation of nutrients by perennial herbaceous legumes with different phosphorus sources at different levels. Four legumes were evaluated: calopo (Calopogonium mucunoides Desv.), forage groundnut (Arachis pintoi Krap. & Greg.), siratro (Macroptilium atropurpureum (OC.) Urb.) and tropical kudzu (Pueraria phaseoloides (Roxb.) Benth.). Each of these species received different phosphorus (P) sources and levels: no phosphate fertilization; 44 and 88 kg of P ha−1 applied as rock phosphate; and 44 kg of P ha−1 as triple superphosphate. Calopo, siratro and tropical kudzu completely covered the soil surface 129 days before forage groundnut. Phosphate fertilization did not increase the dry matter production of any species. The legumes forage groundnut, siratro and tropical kudzu showed desirable characteristics that promote their use as cover crops, such as high dry matter production and shoot accumulation of nitrogen (N) and potassium (K). Forage groundnut had the highest proportion of N derived from the atmosphere at the end of the rainy season, while there were no significant differences between the legumes at the end of the dry season. There was an elevation of soil pH and calcium+magnesium (Ca+Mg) contents, associated with a reduction of aluminum (Al) content, in the surface soil layer (0–5 cm) for siratro in relation to groundnut and tropical kudzu. Tropical kudzu promoted higher soil organic C contents when compared to groundnut.

Herbage and Seed From Texan Native Perennial Herbaceous Legumes

Native seed mixes for rangeland seeding, prairie restoration, or cultivated pasture can benefit from a greater variety of forbs that more closely reflect the original vegetation of the southern Great Plains. Fifteen native, perennial herbaceous legumes were collected in central Texas and evaluated for herbage production, mineral content, and fiber concentration of established plants in research plots over 2 years. Downy milk-pea (Galactia volubilis [L.] Britton) was productive, regardless of rainfall, whereas prairie acacia (Acacia angustissima [Mill.] Kuntze var. hirta [Nutt.] B.L. Rob.) and Illinois bundle-flower (Desmanthus illinoensis [Michx.] MacMill. Ex. B.L. Rob. Fernald) out-yielded others in year 3 when rainfall was the greatest. Herbage crude protein averaged approximately 100 g kg-1 for bush-clovers (Lespedeza spp.) compared to bundle-flowers (Desmanthus spp.), which exceeded 200 g kg-1; the latter also was high in herbage phosphorus. Herbage neutral detergent fiber ranged from 300 to more than 500 g kg-1, acid detergent fiber ranged from 140 to 360 g kg-1, and acid detergent lignin ranged from 36 to 140 g kg-1, a wide range from which to select if animal nutrition is a primary criterion. Seed production was evaluated within a subset of 8 entries submitted to periodic herbage removal or left intact throughout the season. Three bundle-flowers yielded the greatest mass and seed number, but were negatively affected by harvest, unlike prairie acacia. Herbage and seed characteristics indicate there are promising perennial herbaceous legumes in the southern Great Plains that can be included in native seed mixes.

Seasonal variation of arbuscular mycorrhizal fungi in temperate grasslands along a wide hydrologic gradient

We studied seasonal variation in population attributes of arbuscular mycorrhizal (AM) fungi over 2 years in four sites of temperate grasslands of the Argentinean Flooding Pampas. The sites represent a wide range of soil conditions, hydrologic gradients, and floristic composition. Lotus glaber, a perennial herbaceous legume naturalised in the Flooding Pampas, was dominant at the four plant community sites. Its roots were highly colonised by AM fungi. Temporal variations in spore density, spore type, AM root colonisation, floristic composition and soil chemical characteristics occurred in each site and were different among sites. The duration of flooding had no effect on spore density but depressed AM root colonisation. Eleven different types of spores were recognized and four were identified. Two species dominated at the four sites: Glomus fasciculatum and Glomus intraradices. Spore density was highest in summer (dry season) and lowest in winter (wet season) with intermediate values in autumn and spring. Colonisation of L. glaber roots was highest in summer or spring and lowest in winter or autumn. The relative density of G. fasciculatum and G. intraradices versus Glomus sp. and Acaulospora sp. had distinctive seasonal peaks. These seasonal peaks occurred at all four sites, suggesting differences among AM fungus species with respect to the seasonality of sporulation. Spore density and AM root colonisation when measured at any one time were poorly related to each other. However, spore density was significantly correlated with root colonisation 3 months before, suggesting that high colonisation in one season precedes high sporulation in the next season.

Contrasting patterns of leaf solute accumulation and salt adaptation in four phreatophytic desert plants in a hyperarid desert with saline groundwater

The seasonal variation of leaf solutes was investigated in four perennial phreatophytes in the natural vegetation surrounding a river oasis in the Chinese Taklamakan desert in order to elucidate their adaptation to saline groundwater. Leaves of the herbaceous perennial legume Alhagi sparsifolia, the poplar tree Populus euphratica, the salt cedar Tamarix ramosissima, and the C 4 shrub Calligonum caput-medusae were collected at the end of each month during the growing season 1999 and analysed for cation, anion, organic acid, carbohydrate, glycinebetaine, and proline concentrations. The species revealed considerable differences in the foliar solute composition and their seasonal variation. Tamarix had high foliar mineral salt concentrations throughout the season but excreted the accumulated salts via salt glands. The three other species showed different degrees of ion regulation and ion selectivity. Calligonum had generally very low mineral ion concentrations, tolerated moderate Cl − concentrations and excluded Na +. Populus effectively excluded Cl − from its leaves but Na + and total solute concentrations increased towards the end of the season which lead to K:Na ratio smaller than one in October. Alhagi showed the highest degree of ion selectivity by excluding Na + but accumulating Ca 2+ in its leaves. Mineral salt composition of xylemsap in Alhagi and Calligonum indicated that both species showed a similar degree of ion selectivity in the roots and that ion retransloction is probably another important mechanism to maintain low salt concentrations in the leaf. The cyclitols chiro-inositol and pinitol were the major compatible solutes in the plants and N-containing solutes like proline or glycinebetaine occurred only in minor concentrations or were absent, respectively. All plant species were well adapted to the moderate salinity of the NaCl dominated groundwater and no signs of salt related drought stress, ion toxicity or nutrient imbalance were observed.

Organic matter quality in a soil cultivated with perennial herbaceous legumes

Using herbaceous legumes in agricultural systems yields great quantities of plant residues, allowing changes in soil organic matter quality and content over the years. This study was conducted on an Ultisol, at Seropédica, RJ, Brazil, to evaluate the effects of different perennial herbaceous legumes on soil organic matter quality. A factorial scheme with three replications was used to evaluate the species: forage groundnut cv. BR-14951 (Arachis pintoi), tropical kudzu (Pueraria phaseoloides), and siratro (Macroptilium atropurpureum). After the first cut, each plot was divided into two subplots; plants were cut and left on the soil surface or cut and removed. Soil samples of a closed area covered by spontaneous vegetation (mainly C3 plants) or by Panicum maximum were also analysed. Samples were collected from two layers (0-5 and 5-10 cm), processed for the fractionation of organic matter and the evaluation of structural characteristics of humic acids (HA). Evaluated legumes did not change total organic carbon contents, but promoted HA accumulation in the superficial soil layer. Humic acids may be used as indicators of the management effects on soil organic fractions, because there was significant incorporation of carbon and nitrogen derived from the legume residues, even for the short experimentation time (28 months). Residue management did not modify quantitative aspects of the distribution of the humified organic matter, but promoted, however, a higher condensation degree of humic acids evaluated by the elementary composition, IR and fluorescence spectroscopy.

Nitrogen and Carbon Cycling in a Model Longleaf Pine Community as Affected by Elevated Atmospheric CO2

Increasing global atmospheric CO2 concentration has led to concerns regarding its potential effects on terrestrial ecosystem and the long-term storage of C and N in soil. This study examined responses to elevated CO2 in a typical regenerating longleaf pine-wiregrass community. The model community consisted of five plant species: (1) an evergreen conifer (Pinus palustris), (2) a bunch grass (Aristida stricta), (3) a broadleaf tree (Quercus margaretta), (4) a perennial herbaceous legume (Crotalaria rotundifolia), and (5) a herbaceous perennial (Asclepias tuberosa) grown at two CO2 concentrations (ambient and twice ambient). The CO2-enriched plots had greater aboveground biomass than ambient plots, mainly due to increased pine biomass. After 3 years, samples of the soil (Blanton loamy sand: loamy, siliceous, semiactive, thermic Grossarenic Paleudult) were collected from 0- to 5-, 5- to 10-, and 10- to 20-cm depth increments. Microbial respiration, potential C and N mineralization, and C turnover were measured during a 120-day incubation of the soil samples. Elevated CO2 decreased soil C respiration and C turnover, but increased N mineralization. Results indicate that soil C sequestration is likely for soils in this longleaf pine ecosystem.

Perennial herbaceous legumes as live soil mulches and their effects on C, N and P of the microbial biomass

The use of living mulch with legumes is increasing but the impact of this management technique on the soil microbial pool is not well known. In this work, the effect of different live mulches was evaluated in relation to the C, N and P pools of the microbial biomass, in a Typic Alfisol of Seropédica, RJ, Brazil. The field experiment was divided in two parts: the first, consisted of treatments set in a 2 x 2 x 4 factorial combination of the following factors: live mulch species (Arachis pintoi and Macroptilium atropurpureum), vegetation management after cutting (leaving residue as a mulch or residue remotion from the plots) and four soil depths. The second part had treatments set in a 4 x 2 x 2 factorial combination of the following factors: absence of live mulch, A. pintoi, Pueraria phaseoloides, and M. atropurpureum, P levels (0 and 88 kg ha-1) and vegetation management after cutting. Variation of microbial C was not observed in relation to soil depth. However, the amount of microbial P and N, water soluble C, available C, and mineralizable C decreased with soil depth. Among the tested legumes, Arachis pintoi promoted an increase of microbial C and available C content of the soil, when compared to the other legume species (Pueraria phaseoloides and Macroptilium atropurpureum). Keeping the shoot as a mulch promoted an increase on soil content of microbial C and N, total organic C and N, and organic C fractions, indicating the importance of this practice to improve soil fertility.

Adaptation and potential contribution of temperate perennial legumes to the southern Australian wheatbelt: a review

Deep-rooted perennial pasture plants can play an important role in solving the environmental problems of rising watertables, dryland salinity and soil acidification in the wheatbelt of southern Australia. These problems are attributed to the extensive clearing of perennial native vegetation and its replacement with shallow-rooted winter-growing annual crops and pastures. Deep-rooted, herbaceous perennial legumes, particularly lucerne (Medicago sativa L.), are seen as making an increasing contribution in the cropping zones where high rates of symbiotic nitrogen fixation and increased water use are high priorities. This paper reviews the current use and the potential of a range of temperate perennial legumes for the wheatbelt of southern Australia. The genera examined include Medicago, Hedysarum, Trifolium, Onobrychis, Lotus, Galega, Astragalus, Lathyrus, Anthyllis, Psoralea, Dorycnium, Lespedeza and Securigera. There is considerable scope to expand the use of lucerne; however, there is also a need for alternative perennial species to increase biodiversity and to fill niches where lucerne is less suited. Based on current knowledge, the species with the most promise to complement lucerne include sainfoin (Onobrychis viciifolia Scop.) and sulla (Hedysarum coronarium L.) on alkaline soils, strawberry clover (Trifolium fragiferum L.) in wet or mildly saline niches and Lotus and Dorycnium spp. on waterlogged and/or acid soils.

Illinois Bundleflower Genetic Diversity Determined by AFLP Analysis

Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMillan] is an herbaceous perennial legume native to North America. Useful as a N2–fixing plant in warm‐season grass pastures, Illinois bundleflower is also a promising perennial grain crop. Knowledge of the distribution of genetic variation in Illinois bundleflower would increase efficiency of germplasm preservation and expedite plant breeding progress. The objective of this experiment was to determine the distribution of genetic variation within and between Illinois bundleflower accessions by amplified fragment length polymorphism (AFLP) markers. Semi‐automated fluorescence‐based AFLP analysis was performed on three individuals from each of 50 accessions. We identified 222 markers, 159 of which were polymorphic. Within‐accession diversity was low (HS = 0.013) compared with total gene diversity (HT = 0.086). Analysis of molecular variance (AMOVA) showed that 83% of the molecular variance was explained by two major clusters, supporting a previous phenotypic study that suggested the existence of two distinct races of Illinois bundleflower. The less commonly occurring of the two races contained greater genetic diversity and originated from a localized region in the south central USA. The collection of more accessions from throughout the USA and focused on the Southeast would likely increase the genetic variation available to plant breeders.

Elevated atmospheric CO2 affects structure of a model regenerating longleaf pine community

AbstractDifferences in plant morphology, physiology, life form, and symbiotic relationships can generate differences in species responses to CO2‐enrichment, which can alter competitive interactions, thus affecting community structure and function. Here, we present data from a two‐year study, examining the species and community responses to elevated [CO2] of a model regenerating longleaf pine community. The model community was constructed from an assemblage of early successional forest species representing major functional guilds within a typical longleaf pine–wiregrass community: (1) a C3 evergreen conifer (Pinus palustris); (2) a C4 bunch grass (Aristida stricta); (3) a C3 broadleaf tree (Quercus margaretta); (4) a C3 perennial herbaceous legume (Crotalaria rotundifolia); and (5) a C3 herbaceous perennial (Asclepias tuberosa). After 2 years, CO2‐enriched plots had 109% greater above‐ground biomass than ambient plots, mainly due to a 117% increase in pine biomass. Community structure was altered by CO2 enrichment; Crotalaria and Asclepias had higher mortality and less biomass in high‐CO2 plots, suggesting that not all species will perform well as global [CO2] rises. Our data suggest that longleaf pine communities as a whole will perform well in a future higher CO2 world, but some species may fall prey to altered competitive interactions for light and soil moisture.

Root dynamics in an artificially constructed regenerating longleaf pine ecosystem are affected by atmospheric CO 2 enrichment

Differential responses to elevated atmospheric CO 2 concentration exhibited by different plant functional types may alter competition for above- and belowground resources in a higher CO 2 world. Because C allocation to roots is often favored over C allocation to shoots in plants grown with CO 2 enrichment, belowground function of forest ecosystems may change significantly. We established an outdoor facility to examine the effects of elevated CO 2 on root dynamics in artificially constructed communities of five early successional forest species: (1) a C 3 evergreen conifer (longleaf pine, Pinus palustris Mill.); (2) a C 4 monocotyledonous bunch grass (wiregrass, Aristida stricta Michx.); (3) a C 3 broadleaf tree (sand post oak, Quercus margaretta); (4) a C 3 perennial herbaceous legume (rattlebox, Crotalaria rotundifolia Walt. ex Gemel); and (5) an herbaceous C 3 dicotyledonous perennial (butterfly weed, Asclepias tuberosa L.). These species are common associates in early successional longleaf pine savannahs throughout the southeastern USA and represent species that differ in life-form, growth habit, physiology, and symbiotic relationships. A combination of minirhizotrons and soil coring was used to examine temporal and spatial rooting dynamics from October 1998 to October 1999. CO 2-enriched plots exhibited 35% higher standing root crop length, 37% greater root length production per day, and 47% greater root length mortality per day. These variables, however, were enhanced by CO 2 enrichment only at the 10–30 cm depth. Relative root turnover (flux/standing crop) was unchanged by elevated CO 2. Sixteen months after planting, root biomass of pine was 62% higher in elevated compared to ambient CO 2 plots. Conversely, the combined biomass of rattlebox, wiregrass, and butterfly weed was 28% greater in ambient compared to high CO 2 plots. There was no difference in root biomass of oaks after 16 months of exposure to elevated CO 2. Using root and shoot biomass as a metric, longleaf pine realized the greatest and most consistent benefit from exposure to elevated CO 2. This finding suggests that the ability of longleaf pine to compete with sand post oak, a common deciduous tree competitor, and wiregrass, the dominant understory herbaceous species, in regenerating ecosystems may be significantly enhanced by rising atmospheric CO 2 concentrations.

Ecology of herbaceous perennial legumes: a review of characteristics that may provide management options for the control of salinity and waterlogging in dryland cropping systems

Salinity is a widespread problem caused by an imbalance between rainfall and transpiration in the dryland cropping systems of southern Australia. The need to use more perennials has been identified and this paper examines the possibility of replacing annual with perennial pasture legumes and the germplasm available to do so. While lucerne is already used widely in eastern Australia it has only recently been adopted in the wheat belt of Western Australia. There are doubts about its adaptation to acid soils and to climates where summer rainfall is low and ambient temperatures are high. There is also a need to diversify the species available to reduce the likelihood of invasion by exotic diseases and insects. Several genera are likely to be of value in this respect, although few will be as widely adapted as lucerne. Perennial legumes are found in environments ranging from alpine to desert. Targeted collections of genera from the dry areas, especially where soils are acid, are likely to yield species of value. These may include perennial species of Astragalus, Hedysarum, Lotus, Onobrychis, Psoralea, and Trifolium. Some Australian genera, for example Swainsona, Glycine, and Cullen may also be of value. Most of these genera are from alkaline soils, and the need to cope with acid soils that are often high in free aluminium is seen to limit their use in southern Australia. However, since virtually nothing is known of the ecology and ecophysiology of species from the dry areas, it is possible that through selection and the use of adapted rhizobia, some at least may be of value in Australian conditions. Cropping in rotation with perennial legumes is likely to involve several changes in farming systems. It is impossible to predict their nature but it is essential that we understand what these changes are before the species are widely introduced. Account must also be taken of their ability to use water. It is entirely possible that perennials from dry areas are dormant in summer despite the fact that there is no evidence in the literature to this effect. It was concluded that although lucerne is suitable for phase farming, alternatives to lucerne are needed. They will have to match the water-using and nitrogen-fixing capacities of lucerne, and farming systems will be required that make full use of the new germplasm. Collaboration with institutions in the Mediterranean basin and elsewhere is needed and a beginning has been made in this direction.

Variation in Illinois bundleflower (Desmanthus illinoensis (Michaux) MacMillan): A potential perennial grain legume

Illinois bundleflower, Desmanthus illinoensis (Michaux) MacMillan, is an herbaceous perennial legume native to the central and southeastern USA. It has been identified as a potential perennial grain legume. To describe variation among natural populations for agriculturally desirable characteristics, 141 accessions of D. illinoensis and one of D. leptolobus were evaluated in common garden plantings established in 1988 and 1990. Characteristics showing diversity among populations included seed yield, plant height, growth habit, days to maturity, 100 seed weight, and shatter resistance. Eight characteristics were analyzed by principal components and cluster analysis. The resulting four clusters accounted for 56% of the variation among accessions. One cluster was distinctive in having plants with vigorous, prostrate first year growth, poor winter hardiness, and large seed. Three accessions also had indehiscent legumes useful for breeding shatter resistance. There appears to be sufficient variation to support genetic improvement of agricultural characteristics of Illinois bundleflower.

Ecophysiological Observations on Lane Mountain Milkvetch, Astragalus Jaegerianus (Fabaceae), a Proposed Endangered Species of the Mojave Desert

Astragalus jaegerianus, the Lane Mountain milkvetch, a perennial herbaceous legume, is a rare and very narrow endemic of the central Mojave Desert in San Bernardino County, California, and currently proposed to be listed as an endangered species. This herb grows in the protection of low shrubs. Anatomical observations revealed that leaflets are amphistomatic and have isolateral mesophyll, typical of full-sun desert leaves, and the green stem is an important photosynthetic organ, having abundant stomata and a cylinder of cortical chlore nchyma. Ecophysiological studies showed that this species requires high PFD (1400-1500 μmol m-2s-1) to achieve maximum photosynthetic rates and, therefore, is probably not utilizing the nurse shrub for shade but, instead, as a trellis for upper shoots to intercept high PFD. A study of δ15N indicated that this legume is a nitrogen fixer, with higher tissue nitrogen content than other associated species (3.1% versus 1.8%). The herb-shrub association is speculated to be mutualistic, in that the shrub may benefit from higher soil nitrogen when it grows with a nitrogen-fixing legume, and A. jaegerianus likely uses the nurse shrub for protection from herbivores.

Pollen Limitation and Population Growth in a Herbaceous Perennial Legume

woodrat, Neotoma cinerea. University of California Publications in Zoology 110:1-121. Gutierrez, R. J. 1985. An overview of recent research on the spotted owl. Pages 39-49 in R. J. Gutierrez and A. B. Carey, technical editors. Ecology and management of the spotted owl in the Pacific Northwest. U.S. Forest Service General Technical Report PNW-185. Menkens, G. E., Jr., and S. H. Anderson. 1988. Estimation of small-mammal population size. Ecology 69:1952-1959. Montgomery, W. I. 1987. The application of capture-markrecapture methods to the enumeration of small mammal populations. Symposia of the Zoological Society of London 58:25-57. Old-Growth Definition Task Group. 1986. Interim definitions for old-growth Douglas-fir and mixed-conifer forests in the Pacific Northwest and California. U.S. Forest Service Research Note PNW-447. Quinn, J. E, and A. E. Dunham. 1983. On hypothesis testing in ecology and evolution. American Naturalist 122:602617. Rosenberg, D.K., and R. G. Anthony. 1992. Characteristics of northern flying squirrel populations in young secondand old-growth forests in western Oregon. Canadian Journal of Zoology 70:161-166. Rosenberg, D. K., C. J. Zabel, B. R. Noon, and E. C. Meslow. 1994. Northern Spotted Owls: influence of prey base-a comment. Ecology 75: 1512-1515. Sakai, H. E, and B. R. Noon. 1993. Dusky-footed woodrat abundance in different-aged forests in northwestern California. Journal of Wildlife Management 57:373-382. Thomas, J. W., E. D. Forsman, J. B. Lint, E. C. Meslow, B. R. Noon, and J. Verner. 1990. A conservation strategy for the northern spotted owl. Report of the interagency committee to address the conservation strategy of the northern spotted owl. U.S. Forest Service, Portland, Oregon, USA. Volz, K. 1986. Habitat requirements of northern flying squirrels in west-central Oregon. Thesis. Washington State University, Pullman, Washington, USA. Witt, J. W. 1992. Home range and density estimates for the northern flying squirrel, Glaucomys sabrinus, in western Oregon. Journal of Mammalogy 73:921-929. Zar, J. H. 1984. Biostatistical analysis. Prentice Hall, Englewood Cliffs, New Jersey, USA.

Seasonal growth, phosphate response, and drought tolerance of 11 perennial legume species grown in a hill‐country soil

Abstract An experiment was conducted to evaluate 11 species (16 accessions) of herbaceous perennial legumes for their seasonal growth, response to added phosphate (P), and drought tolerance. Different species, and accessions of species, of the genii Adesmia, Medicago, and Trifolium were included. The plants were grown outdoors over 17 months in large (250 mm diameter) undisturbed hill‐country soil cores to provide full expression of their growth habit. Four rates of P were applied to the cores i.e. 0, 0.08, 0.24, and 0.48 g P/core. Herbage growth, stolon extension, and flowering patterns over 8 months were measured, after which the plants were subjected to a simulated summer drought and assessed for stress tolerance and recovery. The accessions showing the greatest growth rate throughout the year included two of T. pratense (Enterprise and a prostrate line); Huia white clover; and the South American legume Adesmia bicolor. The unnamed T. pratense line, and the Adesmia showed particular potential for stron...

Ultimate Functions of Non-Fruiting Flowers in Lathyrus vernus

In this study, four hypotheses concerning female function of non-fruiting flowers in a herbaceous perennial legume, Lathyrus vernus, were examined. I found no evidence that surplus flowers serve to increase the opportunities for maternal selection based on offspring quality, or to decrease seed predation by dispersing oviposition of seed predators. However, a proportion of the cost of surplus flowers may be counterbalanced by gains from increased pollinator attraction and increased fruit set in years with low pollen availability. Furthermore, surplus distal flowers function as reserveovaries if basal flowers are preyed upon or not fertilized. A quantitative model based on the reserve-ovary function predicted half of the surplus flowers actually observed. This study thus suggests that surplus flowers in L. vernus serve several functions simultaneously.

Chromosome morphology in the pasture legume Lotononis bainesii Baker and the related species Lotononis angolensis Welwitsch ex Baker.

Lotononis bainesii Baker, a diploid, and L. angolensis Welwitsch ex Baker, a tetraploid, are self-pollinated, herbaceous perennial legumes native to southern Africa. Because these species are grazing tolerant and have high nutritional quality and palatability, they are under study for summer pasture improvement. Gross morphology of L. bainesii and L. angolensis chromosomes was examined using conventional and C-banding techniques. Ideograms are presented showing that the two species were distinctly different in chromosome morphology and C-banding patterns.

The Biology of Desmanthus Illinoensis

Desmnanth its illinoensis (Michaux) MacMillan is an herbaceous or suffrutescent perennial legume of wide hut sparse distribution throughout the midwestern and southeastern U. S. It occurs rather comnlronly along roadside ditches, at the margins of cultivated fields, in upland swales and on low, open ground. Leaves are twice pinnate and consist of many small, linear leaflets. The numerous dense heads of small, white flowers are borne on axillary peduncles. Flowering begins in late May and early June and may continue into the summer, with both flower buds and bundles of mature, strongly curving capsules occurring on the same plant. This study of Desmanthus illinoensis was undertaken to describe some of the autecological and biological aspects of the species, which has been little investigated from any other than a taxonomic viewpoint. In addition, it is a prairie fork apparently favored by livestock in grazing and thus merits study on the basis of its potential economic value. Data were assembled during the spring and summer of 1957 and 1958 from material observed within a 10 mile radius of Tulsa, Okla. Some of the data was compiled during the spring and fall of 1958 from laboratory plantings at the Agriculttural Experiment Station at the Univ. of Cal., Los Angeles.