H. C. Greene

Bio: H. C. Greene is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 35 citations.

Germination Studies of Wisconsin Prairie Plants

Abstract: The methods and rates of reproduction of the most important prairie species have been studied in some detail in connection with the establishment, on the University of Wisconsin Arboretum at Madison, of large-scale examples of the main plant associations of the prairie-forest border region. To assist with the restoration of the tall grass prairie (Andropogon-Sorghastrum) variotus additional studies have been made concerning the species composition of nearby prairie relics (Curtis and Greene, 1949), and the effect of fire on the behavior of prairie perennials (Curtis and Partch, 1948). The present paper reports briefly on one phase of the reproduction studies, namely the germination behavior of the seeds of 91 species of prairie plants.

Growth Patterns of Some Native Annual and Perennial Herbs in Southern Wisconsin

Abstract: Temporal growth patterns and adaptive characters were studied in 17 perennial, 16 annual, and 4 biennial native herbs for one to three growing seasons in dry-mesic, mesic, and wet-mesic forest and in open barrens in southern Wisconsin. In annuals almost all dry matter produced was retained in aerial organs following the initial growth period. Below- ground weight increased rapidly in early season and then slowly increased or declined. In perennials there was a predominantly upward weight movement during growth initiation and during flowering and fruiting and a downward movement between growth initiation and flowering and preceding aboveground senescence or death. Between autumn and spring, all perennials, including wintergreens, lost weight. Most winter annuals increased in both above- and below- ground dry weight over winter, demonstrating maintenance above the compensation point. Growth patterns of biennials in their first year were similar to perennials and in their second year were similar to annuals. Forest herbs lost less water before wilting, were more succulent, wilted in a shorter time, and had heavier seeds than herbs of open habitats. The seeds of the forest annuals were heavier and germinated more readily than seeds of forest perennials. Although most annuals are pioneer, drought-resistant plants, forest annuals wilted easily and were very succulent. This suggests that stems and leaves of the annuals apparently are supported more by turgor pressure, while the perennial plants are supported more by cell wall thickening. This special dependence of annuals on water correlates with their greater numbers in wet-mesic and mesic forests compared with drier forests. Growth characteristics are discussed for eight forest annuals: Amphicarpa bracteata, Ellisia nyctelea, Floerkea proserpinacoides, Galium aParine, Impatiens pallida, Parietaria pennsylvanica, and Pilea pumila.

The impact of invasive grasses on the population growth of anemone patens, a long‐lived native forb

Abstract: Negative impacts of invasive plants on natives have been well documented, but much less is known about whether invasive plants can cause population level declines. We used demographic models to investigate the effects of two invasive grasses on the demography and population growth of Anemone patens, a long-lived native perennial of North American grasslands. Demographic data of A. patens growing in patches characterized by Bromus inermis, Poa pratensis, or native grasses were used to parameterize integral projection models. Models based on both average conditions and those allowing for environmental stochasticity indicate that A. patens is slowly increasing in patches of native grass (λ = 1.02) and declining in patches of invasive grasses, particularly those dominated by B. inermis (λ = 0.93). Extinction probabilities indicate that A. patens should persist in native grass patches, but has a much higher probability of extinction in Bromus patches compared to Poa patches. While sensitivity analyses showed that survival had the biggest effect on population growth rates in all habitats, results of a Life Table Response Experiment (LTRE) revealed that slower individual growth rates in patches of invasive grasses contributed the most to the observed reduction in population growth. These results suggest that invasive grasses may cause slow declines in A. patens, despite short-term coexistence, and that controlling B. inermis only would not be sufficient to ensure A. patens persistence.

Atlas of the Wisconsin prairie and savanna flora

Abstract: This Atlas of theWisconsin Prairie and Savanna Flora treats most of the native vascular plants of Wisconsin grasslands and savannas from the standpoint of floristics and phytogeography. Included are 341 species and 73 additional subspecies, varieties, and hybrids (discussed and mapped) as well as 103 species and 50 infraspecific taxa and hybrids (discussed or casually mentioned). Part I discusses the physical geography and climate of Wisconsin; the composition of its prairie, barrens, and savanna communities; and the history of its flora. Part II consists of 354 dot maps showing the exact distributions of the taxa as based on herbarium specimens, each accompanied by a statement describing the plant’s habitats, abundance, and overall distribution. One of the practical uses of this work is to help guide ecologists and conservationists in the planning of prairie restorations.

Ability of cold-tolerant plants to grow in hydrocarbon-contaminated soil.

Abstract: Phytoremediation of hydrocarbons in soil involves plants and their associated microorganisms. Differences in environmental conditions and restrictions on species importation mean that each country may need to identify indigenous plants to use for phytoremediation. Screening plants for hydrocarbon tolerance before screening for degradation ability may prove more economical than screening directly for degradation. Thirty-nine cold-tolerant plants native, or exotic and naturalized, in western Canada were assessed for their ability to survive in crude oil-contaminated soil. Four naturalized grasses (i.e., Agropyron pectiniforme, Bromus inermis, Phleum pratense, and Poa pratensis), three naturalized legumes (i.e., Medicago sativa, Melilotus officinalis, and Trifolium repens), two native forbs (i.e., Artemisia frigida and Potentilla pensylvanica), one native grass (i.e., Bromus ciliatus) and two native legumes (i.e., Glycyrrhiza lepidota and Psoralea esculenta) exhibited phytoremediation potential, based on sur...

Progress and Bottlenecks in the Early Domestication of the Perennial Oilseed Silphium integrifolium, a Sunflower Substitute

Abstract: Silflower (Silphium integrifolium Michx.) is in the early stages of domestication as a perennial version of oilseed sunflower, its close relative. Grain crops with deep perennial root systems will provide farmers with new alternatives for managing soil moisture and limiting or remediating soil erosion, fertilizer leaching, and loss of soil biota. Several cycles of selection for increased seed production potential following initial germplasm evaluation in 2002 have provided opportunities to document the botany and ecology of this relatively obscure species, to compare agronomic practices for improving its propagation and management, and to evaluate the differences between semi-domesticated and wild accessions that have accrued over this time through intentional and unintentional genetic processes. Key findings include: domestication has increased aboveground biomass at seedling and adult stages; seed yield has increased more, achieving modest improvement in harvest index. Harvest index decreases with nitrogen fertilization. Silflower acquires nitrogen and water from greater depth than typical crops. In agricultural silflower stands within its native range, we found that Puccinia silphii (rust) and Eucosma giganteana (moth) populations build up to unacceptable levels, but we also found genetic variation for traits contributing to resistance or tolerance. Breeding or management for reduced height and vegetative plasticity should be top priorities for future silflower research outside its native range.