Research Questions

The following research questions address plant taxa that are globally or regionally rare. The New England Wild Flower Society has recently published comprehensive Conservation and Research Plans that review the conservation status of each taxon and that suggest specific actions to ensure their conservation within their New England range over the next twenty years. Abridged versions of these Plans are available for download at our web site by clicking on the taxa below, and provide an excellent general introduction to the ecology of the taxon and the known causes of its rarity. Most of these Plans pinpoint areas where we lack basic knowledge on the biology of the plant -- knowledge that is critical to understanding how best to conserve and protect it. Thus, the New England Wild Flower Society seeks to fund basic research studies that will elucidate the factors that influence plant fitness, interactions among populations, and population trends. These studies may yield some of the first data available on these plants, and will assist with conservation planning for these and many other rare plants. The questions that follow derive directly from the Conservation and Research Plans themselves.

As you design a research study to address these questions, we recommend you take the following steps:

1. Perform background research on the taxon.

• Read the Conservation and Research Plan relating to the species http://www.newfs.org/conplans.html 
• Search for other sources of information on the species (see "Tips for Searching for Information on Plants” http://www.newfs.org/researchtips.htm
• Use your own knowledge of other plants to form hypotheses. Bounce your ideas off your academic advisor or other knowledgeable biologists. 

2. Design an experiment or set of experiments to address the hypotheses you have generated. Keep in mind the following:

• Non-destructive field experiments should be performed. We do not wish to endanger plant populations in the process of studying them. Experimental design will be contingent on permitting by the relevant Natural Heritage Programs and on obtaining landowner permission. Thus, you should develop your design to be as non-invasive as possible and to minimize logistical difficulties.  If you are awarded a fellowship, you should be prepared to work flexibly in developing your final design.
• Simple, inexpensive techniques can be extremely effective for obtaining good information.
• Remember to build adequate replication and statistical power into your design (or review statistical techniques that will permit analyses of small data sets).

Research questions relating to specific taxa: 

Adiantum viridimontanum http://www.newfs.org/pdf/Adiantumviridimontanum.pdf

• Perform species biology research to investigate ecological distributions and interactions among members of the Adiantum pedatum complex. Several aspects of Green Mountain maidenhair fern’s biology are poorly understood. In particular, further research is recommended to examine how members of the Adiantum pedatum complex are distributed across ecological gradients and how members of the complex interact in locations where they co-occur. 
• Increased knowledge of the hybridization frequency between Adiantum viridimontanum and its progenitors would be useful, as would information about the factors that influence the formation, distribution on the landscape, and success of species and hybrids. Field investigations of these questions would be aided by a better description of field characters that can be used to distinguish A. viridimontanum from its hybrids.
• Information about spore viability under various storage regimes is currently lacking, so the success of spore banking as a conservation action will depend on further research in this area.

• Determine habitat preferences. Comparisons with habitat preferences of prolific southern populations could be especially helpful. Create a model for optimum habitat on Nantucket and in New England to provide a habitat management target.
• Investigate reproductive biology. Determine whether the species is self-compatible; determine levels of reproduction in the wild; investigate its response to fire.
• Determine metapopulation status. Investigate and map the spatial configuration of all EOs; determine dispersal distances and potential for migration to existing EOs or colonization of new habitats; determine length of persistence of occurrences (sub-populations) with and without disturbance; determine the longevity of the seed-bank.
• Develop an understanding of A. concolor’s pollinators, especially their habitat requirements and range of travel in order to help determine connectivity of sub-populations.
• Investigate the role of insect herbivory and seed predation. Specifically, investigate the role of herbivory by rabbits, particularly the impact of the introduced Eastern Cottontail on Nantucket, to determine if reintroduction would be more successful in areas inhabited only by the native New England cottontail.
• Determine Aster concolor’s response to specific management methods in order to refine the management plan to enhance and sustain all populations of the species in New England.

• Quantify areal extent, number of stems, and number of sexually reproductive culms for each population.
• quantify seed production.
• Determine possible threats of invasive exotic plants.

• Contact should be made with the New Jersey Heritage Program botanists who likely have considerable experience with the species. The habitat conditions that promote germination and establishment of C. barrattii should be investigated in addition as to how these conditions might be promoted in natural populations. Many biologists who were contacted mentioned the probability that fire plays an important role in the reproductive success of the species. Study plots should be established so that controlled burning could be contrasted with canopy clearing and the end results closely monitored. Reproductive success could then be measured for the different treatments.
• The taxon’s response to water levels should also be investigated.

Carex polymorpha http://www.newfs.org/pdf/Carexpolymorpha.pdf

• Previous investigators (e.g., Standley 1989) report little success in germinating seeds of Carex polymorpha. More research on seed germination in the field and greenhouse is needed.

Castilleja coccinea http://www.newfs.org/pdf/Castillejacoccinea.pdf

• Soil studies and species inventories of the extant sites should be carried out to determine whether any broad generalizations can be made about the range of soil factors that support the species.
• Determine the extent to which shading (and removal of shade) influences growth, survivorship, or recruitment of the species.
• The plant is a hemiparasite, but its host requirements are unknown. Identifying associated species might be important in developing a profile of appropriate habitat. William Moorhead (personal communication) has observed at the extant sites a suite of associated species that tend to be associated with alkaline soils. He feels that the species may be associated with seeps in soils deriving from limestone bedrock or calcareous tills. Leslie Mehrhoff (personal communication) considers associated species such as Gentianopsis crinata and Parnassia glauca to be more generally indicative of rich sites. Likewise, Linke (1980) and Smith (1983) independently report this species associated with Indian paintbrush at different sites. The work done on C. coccinea by Malcolm (1962a, 1962b) and evidence from other species of the same genus (Heckard 1962, Mills and Kummerow 1988) indicates the genus is a rather generalist parasite. However, Marvier (1998) found that host quality varies and a "mixed diet" promotes the highest reproductive success while diminishing the growth of herbivores on C. wightii. Marvier and Smith (1997) discuss the potential importance of recognizing and preserving the appropriate host assemblage to the conservation of parasitic plant species. Using a list of the associated species at CT. 004, common garden experiments should be undertaken to determine whether some hosts support greater reproductive success in C. coccinea. Host-parasite relationships may also influence germination success.
• Effects of disturbance on the species: churning of wetland soils by some type of grazing mammals was an historically important component of the Indian paintbrush ecology. Each of the two most viable extant sites has experienced some soil disturbance annually for several years: one is mowed for hay and the other was grazed until recently. Disturbance should be explored in the field to determine how it might affect the success of germination and recruitment.
• This evidence seems to indicate that pollinator availability is not limiting seed production at this site. However, Allee effects might be important in the smaller extant populations. In variably sized experimental plots, Allee effects should be explored by comparing seed set between "populations" as a consequence of different plant densities.

Corydalis flavula http://www.newfs.org/pdf/Corydalisflavula.pdf

• Determine whether removal of encroaching shrubs at one Connecticut site enhances survivorship, growth, and recruitment of the plants.
• Determine whether the species is capable of forming a seed bank in New England.
• Determine primary pollinators of the species in Connecticut (these may include a rare butterfly!) and assess the relative contributions of insect pollination and self-pollination (cleistogamy) to reproductive success

Cynoglossum virginianum var. boreale
 http://www.newfs.org/pdf/Cynoglossumvirginianum.pdf

• Research pollinator ecology and possible pollinator limitation: An experiment comparing flowers that are hand-crossed, self-pollinated by hand, and bagged to exclude pollinators should be performed to quantify pollinator limitation and out-crossing effects on seed set at either the sites in Maine or New Hampshire. In populations where pollinator visitation is believed to limit seed production, flowers should be hand-pollinated to decrease pollinator limitation due to small population size. An additional benefit is that deleterious genetic effects may be reduced by hand-crossing pollen.

Diphasiastrum sitchense http://www.newfs.org/pdf/Diphasiastrumsitchense.pdf)

• Special studies on clonal size, productivity and fertility are encouraged to determine growth rate, extent and possible extent of clones, and to determine optimum sustainable populations. No guidelines as to the definition or measurement of this optimum can be given at present; they should be developed by anyone undertaking such research.

Eriocaulon parkeri http://www.newfs.org/pdf/Eriocaulonparkeri.pdf)

• Specific observations should be directed to determine phenology, pollination mechanisms and vectors, pollen viability, seed production, seed dispersal, and seed germination. Determining method of pollination may be difficult, as standard techniques such as emasculation and pollen exclusion bags will not work for this aquatic species without modification. Pollen viability, seed production, and seed germination studies might be expanded to explore differences in location and water quality (urban versus rural sites) in an effort to understand the declines of this species from populated areas.

Hasteola suaveolens http://www.newfs.org/pdf/Hasteolasuaveolens.pdf

• What is the relative importance of sexual reproduction versus vegetative propagation to the persistence of populations?
• Is H. suaveolens self-incompatible and is the number of compatibility groups in our populations small enough to limit seed production?
• Is a lack of suitable pollinators responsible for low seed set in our populations?
• What are the conditions that promote germination and establishment of H. suaveolens? How might these conditions be promoted in natural populations?
  
• Which life history stages are most important to limiting population growth of H. suaveolens?
• What are the ecological differences between the site where the New England population occurs and the sites of large, healthy populations in other states that could account for the difference in population size?

Hydrophyllum canadense 
http://www.newfs.org/pdf/Hydrophyllumcanadense.pdf

• Develop a consistent, efficient, and minimum-impact monitoring technique to accurately assess population sizes and trends over time while minimizing potential negative impacts such as trampling plants and damaging the habitat during sampling. It will be informative to use some combination of counting plants and mapping the locations of concentrations of the plants. It will be important to determine the most practical and accurate way to count plants. Currently, stems, clumps, and plants have been used to describe the plants; this likely results in counts that are not comparable. Ideally, a standardized sampling regime should be established for all of the populations using one measure.
• Determine optimal light, moisture, and nutrient levels for the species.
  
• Determine the relative importance of sexual and asexual reproduction.
  
• Determine the impacts of exotic invasive plant species and means of controlling them.
  
• Determine the role of disturbance (e.g., flooding and ice scouring) in the population ecology of the plant; determining the nature of herbivory seen in populations.
  
• Determine the impacts of various current land uses and investigate land use history and its impact on populations.

Hypericum adpressum http://www.newfs.org/pdf/Hypericumadpressum.pdf

• Some populations of Hypericum adpressum are characterized by robust plants with spongy stems and thickened bases, called forma spongiosum. In general, typical H. adpressum appears like an annual plant, with population numbers fluctuating from year to year based on the depth of water and consequent degree of pond shore exposure at particular sites. In contrast, the spongiose form of H. adpressum occurs as one component of relatively persistent emergent plant communities that develop in the littoral zone of ponds that do not undergo significant annual water level fluctuations. In the first situation (typical H. adpressum), populations are dependent on unpredictable and highly fluctuating water levels that result in ephemeral shoreline exposure. In the second case (form spongiosum), populations persist and remain relatively unchanged over the course of many years. Thus, conservation strategies must be adapted to the particular ecology of the subject habitat. One particular biological question regarding the conservation of H. adpressum concerns the taxonomic and ecological significance of the two forms of this species: typical adpressum and the form spongiosum. Although it is assumed that the morphological differences between these two forms are due to environmental factor (stability of water level and degree of immersion), it is possible that genetic variation may also be indicated.

Liatris borealis http://www.newfs.org/pdf/Liatrisborealis.pdf

• Collect demographic data including reproductive status, mortality, and seedling establishment. These vital rates determine the growth or decline of a population, and these trends are necessary to evaluate the status of a population and determine the Minimum Viable Population size. To collect demographic data, set up permanent plots or transects through a population, tag individual plants with permanent markers such as metal tags, and check plants one to three times annually to determine recruitment, mortality, reproductive success, and what stage is limiting population success over several years. Use matrix projection models to assess both population growth trajectories and identification of sensitive life history stages.
  
• Conduct inbreeding depression studies. Inbreeding depression can be assessed by comparing relative seed set of hand-selfed and hand-outcrossed individuals with seed set of untreated, open-pollinated plants. Investigate progeny vigor of the three treatments as well.
  
• Further investigate the role of seed predators. Clarify the relationship of L. borealis and seed predating microlepidopteran moth species. Continue work of Dr. David Wagner (University of Connecticut) on rearing out larva collected from L. borealis seed heads. Of particular ecological importance and interest is the previously unknown tortricid species that may be an obligate feeder of L. borealis. If this is the case, the fate of this insect species will depend on the fate of its host plant.
  
• Investigate geologic habitat preferences. Take soil samples from sites throughout the range and analyze to make generalizations about required soil types. The existence of soil preferences could also be examined by using soil maps. Populations can be located, via Global Positioning Systems (GPS) or traditional techniques, on geologic maps. These maps can be used to search for soil and other geological patterns in habitat preference. A GIS data base, which is updated with information from monitoring every 1 to 5 years, would be beneficial to conservation of this plant for many reasons. Such a database would enable assessment of trends by area in extirpation, habitat type, geologic preferences, and other important characteristics.
  
• Investigate seed dispersal. Conduct studies to determine dispersal ability of L. borealis. This can be done by setting up seed traps along transects radiating out from populations of the taxon. Genetic data may help to determine the frequency of rare long-distance dispersal events.
  
• Test for presence and longevity of a seed bank.
  
• Determine reproductive age and life expectancy. Basic life history characteristics are not known about L. borealis, and this information is valuable in assessing the health of a population. Individual plants should be tagged and followed throughout their life cycle to determine reproductive age and life expectancy of this species. These data can be obtained as part of the demographic studies recommended above.

Listera auriculata http://www.newfs.org/pdf/Listeraauriculata.pdf

• Searching for new populations presupposes an accurate description of auricled twayblade's preferred habitat; there are many alder thickets along streams in northern New England, but not many harbor populations of auricled twayblade. Research is necessary to identify possible habitat; to discover dispersal mechanisms (e.g., tolerance of seeds for water dispersal and effectiveness of wind as a dispersal agent for short-statured plants); to determine how big an area can support a metapopulation (so we can comfortably decide to protect a certain size of preserve); and to develop a template to guide searches for new populations.

Ludwigia polycarpa http://www.newfs.org/pdf/Ludwigiapolycarpa.pdf

• Study the hydrological requirements of the species and its habitat.
  
• Study the relationship between light levels and occurrence and vigor of individuals and populations.
  
• Study life history components and determine potentially vulnerable stages in the life cycle.

Ludwigia sphaerocarpa http://www.newfs.org/pdf/Ludwigiasphaerocarpa.pdf

• In light of growing demands for water withdrawal within its coastal plain habitat, the most critical information needed in terms of long term management is L. sphaerocarpa's response to water level changes, both natural and artificial. By investigating historic water level fluctuations for existing stations, it may be possible to determine the range of tolerance for water level variation. Any field investigations along this line should also note the relationship of other rare plant species to water level fluctuations/manipulations.
  
• Additional information on population demographics is also desirable. Data confirming the growth patterns and vigor of populations in sheltered versus exposed micro-habitats would contribute to the tailoring of future conservation actions.

Mimulus moschatus http://www.newfs.org/pdf/Mimulusmoschatus.pdf

• In addition to the above extant occurrences, there are two historic naturally occurring populations in Deerfield and Orange, Massachusetts. Efforts to find these occurrences should be pursued. Locating these occurrences would be important in extending the geographical distribution of the species. There are also reports of undocumented populations in northern Vermont, which should be researched and surveyed.
  
• Collect basic demographic data on existing populations.
  
• Perform a morphological analysis (possibly complementing a genetic analysis pending other, larger funding sources) of the affinity and relatedness of New England and western populations of Mimulus moschatus.

Neobeckia aquatica http://www.newfs.org/pdf/Neobeckiaaquatica.pdf

• Ecological investigations should investigate the demography of fluctuating populations.
  
• Determine critical life stages that may be influencing population fluctuations.
  
• Determine physical factors that may influence population fluctuation. Studies of habitat preferences -- namely, pH requirements, optimal light regimes, and requirements for sediment composition and nutrient levels -- should be undertaken.
  
• Determine biotic interactions that may influence population fluctuation. Biological interactions, including potential herbivore interactions and the existence of symbiotic relationships, should be documented.

Panicum flexile http://www.newfs.org/pdf/Panicumflexile.pdf

• Study ecological interactions to determine how seed dispersal and herbivory affect plant population structure. Assess the plant’s response to natural and anthropogenic disturbance.

Paronychia argyrocoma http://www.newfs.org/pdf/Paronychiaargyrocoma.pdf

• Identify pollinators in at least three separate locations, one montane, one along the Saco River, and the Massachusetts site.
  
• Other studies of limiting factors influencing dispersal, germination, and establishment of successful reproductive populations would be valuable.

Pedicularis lanceolata http://www.newfs.org/pdf/Pedicularislanceolata.pdf

• At this time, no population viability analysis of Pedicularis lanceolata has been performed, and so it is difficult to state specific, quantitative conservation objectives for population sizes and numbers of this taxon with any degree of confidence. Because P. lanceolata is short-lived, is not self-pollinating, and is relatively late-flowering, large populations may be required in order to maintain viability. Turnover rate in short-lived species is greater than that in longer-lived species, and so more plants are needed to allow for yearly fluctuations in survival rates. Species that are not self-pollinating require enough other individuals within traveling distance of pollinators to achieve pollination and seed set. Finally, plants that are insect-pollinated and are late-flowering may need to be present in enough abundance to meet the nutritional requirements of pollinators without help from many other species. Studies of another species of Pedicularis can provide some insight into the issue of population size. A species with similar habitat requirements and life history, Pedicularis palustris, inhabits "fen meadows" in Europe (Schmidt and Jensen 2000) and wet soil in eastern Canada (Gleason and Cronquist 1991: 487) and is becoming rare in some European countries. Like P. lanceolata, it is short-lived and is primarily out-crossing (Macior 1993). In a single-year examination of 13 extant populations in Germany and Norway, populations were shown to be highly variable, having between three and 28,500 flowering individuals each (Schmidt and Jensen 2000). In this species, larger populations were correlated with higher numbers of capsules per plant and with higher numbers of seedlings per flowering plant.
  
• Another way to shed light on objectives for size of viable populations of P. lanceolata is to perform demographic studies of occurrences in parts of the country where it is not endangered and to compare these with New England populations. Potential differences in climate, vegetation, and pollinators must be considered when applying results of such studies in New England.

Sclerolepis uniflora http://www.newfs.org/pdf/Sclerolepisuniflora.pdf

• What is an individual plant? This species reproduces primarily vegetatively; so are clumps of plants clones or is the entire population in a lake a clone?
  
• How should abundance be determined and reported?
  
• What conditions stimulate terrestrial growth and flowering?
  
• Can this species maintain itself in the aquatic form indefinitely?
  
• Can it over-winter in terrestrial form?
  
• When flowering, is pollen viable? Are seeds produced? Are seeds fertile?
  
• Why have seed not been found after flowering at one of the populations?
  
• Can Sclerolepis compete and coexist with the invasive aquatic plant, Myriophyllum heterophyllum?
  
• Since the New England occurrences are the most northern populations, how do these peripheral populations of Sclerolepis compare with plants from the rest of the range?
  
• Are these two isolated northern populations genetically variable or are they predominantly one clone?
  
• Are New England plants genetically different from the rest of the range?
  
• What is the range of variability in lake water levels, which maintain or create suitable habitat for Sclerolepis? Can we obtain information on historic water levels in Wallum Lake at the turn of the century?
  
• How does water level affect flowering and seed set?
  
• What environmental factors affect growth?
  
• What effect will efforts to control or eradicate Myriophyllum heterophyllum have on Sclerolepis?
  
• What effect does lake liming have on Sclerolepis?
  
• How does this species respond to disturbance from boating?
  
• To what depth do these plants grow and what effect does boating have on the cutting of fragments and the stranding of material on shore?
  Field and greenhouse studies should be conducted on New England plants to investigate the above questions. Additional information may be gained by examinations of populations outside of New England.

Senna hebecarpa http://www.newfs.org/pdf/Sennahebecarpa.pdf

-- At several extant sites, species biology research should be conducted with particular attention to insect interactions, pollination, seed dispersal, longevity of individual plants, and response to disturbance.
-- Possible symbioses with nitrogen-fixing bacteria may be necessary for the species to grow; these interactions need to be characterized.
-- Additional research should be conducted to determine seed viability (cross-pollination, low genetic variability), seed longevity (to determine seed bank effectiveness), and symbiotic bacteria.

Triphora trianthophora http://www.newfs.org/pdf/Triphoratrianthophora.pdf

• Determine optimal and acceptable light, moisture, and leaf litter and soil conditions that optimize plant growth, survivorship, and reproduction. Paired comparisons of beech-dominated sites that do and do not support Triphora trianthophora may be informative.
  
• Although impacts from timber harvest are generally viewed as negative for forest herbs, canopy thinning may be appropriate in conditions that are thought to be too shaded. Determine general light requirements for the orchid. Woody debris is also known to be important for seed germination in certain orchid species (Rasmussen and Whigham 1998); is it important to T. trianthophora?.
  
• Study mycorrhizal and saprophytic relationships. Because mycorrhizal associations are likely to be crucial to the existence of the orchid, they should be considered for study; studies on other orchids may provide insights as to the importance of additional information for management and the costs to populations of conducting such research (Taylor and Bruns 1997 and Kristiansen 2000).
  
• Describe pollination ecology, primary pollinators and rates of activity, rates of outcrossing and inbreeding in populations.
  
• Quantify seedling establishment and compare the relative contribution of vegetative and sexual reproduction to population growth.
  
• Quantify impacts of herbivory on plant survivorship and reproduction.

Trollius laxus http://www.newfs.org/pdf/Trolliuslaxus.pdf

• The impact of competition can be assessed without identifying limiting factors, with a simple experiment. Divide a site into at least eight sections (or use each individual as a sample in very small populations). Early in the season soon after emergence, hand clip immediate neighbors at ground level and cut back any other plants overhanging the Trollius in half of the plots, randomly chosen. Visit monthly throughout the growing season and clip again as necessary to minimize encroachment in the treated plots. Compare flower and fruit production that year and the following year, as effects on reproduction may not be manifested until the following year.
  
• During the site visits, examine the plants for evidence of predation and the presence of small herbivores such as slugs and insects. Collect specimens of any such herbivores and estimate abundance and damage levels. During the blooming season, observe the flowers at different times of day in sunny weather and identify all visitors. Collect voucher specimens of visitors for positive identification and examine the pollen on their bodies for amount and plant species. To assess the effectiveness of pollination, use a small paintbrush to cross-pollinate all flowers of randomly chosen plants, then compare seed production per plant between open pollinated and hand-augmented plants (Bierzychudek 1981).
  
• Test for the presence of a seed bank in populations with no fruit production in a given year. Take small shovelfuls of soil in the vicinity of the larger Trollius plants in late fall or early spring. Put some in flats outdoors and keep moist until they freeze for the winter, and subject others to treatment optimal for Trollius germination in cultivation (Brumback 1983). Look for Trollius seedlings emerging in the spring and summer. Alternatively, dry the soil samples, sieve, and search for seeds, then sow.
  
• Determine the source and chemistry of water inputs to the wetlands supporting Trollius, and ascertain whether these are groundwater discharge wetlands. Locate records or collect data indicating periodicity and extent of natural flooding. 

Due date for proposals: February 5, 2003. Notification of Fellowships will be made in early March, 2003. 

For more information, please contact: Elizabeth Farnsworth (413) 534-6572, electronic mail: efarnswo@mtholyoke.edu

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