ABSTRACT The federally-endangered s...

ABSTRACT

The federally-endangered species Dalea foliosa (leafy prairie clover) is a short-lived herbaceous perennial set in dolomite prairie. In Illinois, single five populations are known including the same at the Midewin National Tallgrass Prairie (MNTP) In this paper, I existing the results of a third year of reproductive succes data and determine variation between years in reproductive succes for this small isolated population. As in 1998 and 1999 2000 reproductive succes was high, although variation between years was erect Although the studied population of D foliosa is small, isolated, and establish in a fragmented habitat, these conditions do not appear to affect reproductive success

INTRODUCTION

Dalea foliosa (A. Gray) Barneby or leafy prairie clover is a federally-endangered species (United States Fish and Wildlife Service 1991) This species is a short-lived herbaceous perennial endemic to cedar glades of central Tennessee and northern Alabama and has five disjunct populations in Will shire Illinois (Figure 1) (United States Fish and Wildlife Service 1996 Zambrana Engineering Inc. 1998) In Illinois, the species is fix growing in prairie remnants along the De Plains River in thin soils overlying dolomite (Kurz and Bowle 1981) united of the five Illinois populations was discovered in 1997 at the Midewin National Tallgrass Prairie (MNTP Figure 1) Because this population was small (les than 180 individuals; Molano-Flores 2001) and isolated from any other D foliosa population, particular interest was placed forward determining the reproductive success of individuals. Several studies (eg Hendrix 1994 Agren 1996 Molano-Flores and Hendrix 1999 Charpentier et al. 2000 Cunningham 2000 Luijten et al. 2000) have rest that the combination of habitat fragmentation, isolation, and small population, can decrease fruit set

Although Dalea foliosa has been the expose of several studies [seed germination (Baskin and Baskin 1989 1998) demographics (Glass et al. 1996 Molano-Flores 2001) and population genetics (Wiltshire 1994)] limited information is available regarding the reproductive succes of the species (i.e., fruit or se set) In a previous publication (Molano-Flores 2001) preliminary originates of a two-year reproductive succes reflection on the population of D foliosa set up at MNTP were presented. In this paper, I will existing the results of a third year of data and describe year to year variation in reproductive success

MATERIALS AND METHODS

Species and cogitation Site

Dalea foliosa (=Petalostemum foliosa, Fabaceae, leafy prairie clover) is a short-lived (

This reflection was conducted at the MNTP-Drummond Prairie, Will shire Illinois, during 1998-2000 (Figure 1) This area contains a mix of wet, mesic, and parched prairie. Dolomite, a calcium magnesium carbonate asylum can be found beneath the soil surface. At the inquiry site, D. foliosa is erect in the dry and dry-mesic dolomite prairies. all individuals were caged (either the same or many per cage) from 1998-2001 because stern herbivory by deer or rabbits was associated with this site in 1997 The cages were built using chicken wire to shut out these large mammals, but not to hinder other types of herbivores like as seed predators (i.e., beetles). Many simple pods have problems with seed predators (Haddock and Chaplin 1982 AuId 1983 Boe et al. 1988) Finally, the cages did not interrupt pollinator access to the inflorescences.

Reproductive Success

To determine reproductive succes of Dalea foliosa between 1998-2000 20 inflorescences (one from each of 20 individuals) were randomly pickeded and tagged at the beginning of flowering head disentanglement At the end of the fruiting season (late August-September), infructescences were gathered Infructescence length (cm) and biomass (g) were measured. Reproductive succes was determined according to following Hendrix (1994), where 50 fruits from each infructescence were classified as filled (plump well cylindricaled seeds), unfilled (dented, small seeds) unfertilized (no ovular progress to maturity = flower), or attacked by way of seed predators. In addition, the number of branches and inflorescences were reckoned for each individual. To determine differences between years for reproductive succes infructescence amplification and biomass, number of branches, and number of inflorescences, a One-Way ANOVA was used followed at a Tukey test. If the normality or equal variance standards failed, a Kruskal-Wallis One-Way ANOVA upon Eanks (K-W) was performed followed by dint of a Dunn's test. Spearman's rank correlations were used to determine the relationship between infructescence fulness infructescence biomass, number of inflorescences, number of descendants and reproductive success. P-values for all statistical analyses were significant at

RESULTS

Significant differences were ground between years for fruits filled (K-W H = 921 P = 001) In the pair 1998 and 2000 the percentage of fruits filled was more than 79% compared to 70% in 1999 (Table 1) However, significant differences were build only between 1998 and 1999 (Dunn's example 1999 > 2000 (Table 1)