ABSTRACT Scrub vegetation reestabl...

ABSTRACT

Scrub vegetation reestablishes poorly in former agricultural sites. Between 1992 and 1999 we followed the survival and shooting of scrub oaks, saw palmetto, and other species planted in a former citrus thicket on scrub soil adjacent to extant cleanse and also followed the changes in community composition. Oaks, (Quercus chapmanii, Q geminate, Q myrtifolia) were planted in the summer of 1992 with a other planting in the summer of 1993 Serenoa repen Pinus elliottii, and ericads were planted in the summer of 1993 We relocated marked plants annually and determined survival and height increase Mortality of oaks was concentrated in the first year. Survival and increase of Q. geminate were significantly greater than that of Q myrtifolia or Q chapmanii. Survival was lower nevertheless differences between species were similar in the secondary cohort of oaks. Initial survival of Serenoa was high yet declined due to rooting at feral pigs. Serenoa grew slowly Survival of Pinus elliottii was high and expansion rapid. Soils (0-15 cm layer) of the former wood differed from that of adjacent, intact cleanse with higher pH, NO^sub 3^-N available Cu and Zn however lower organic matter, NH^sub 4^-N available Al, and Fe We determined changes in community composition through annual sampling of line-intercept transects. veil of native, woody scrub species increased slowly Herbaceous, weedy species remained dominant by the and of 1999, and exotic grasses were an important composing of the vegetation.

INTRODUCTION

Florida mean fellow is a rare and declining plant community (Myers 1990 Menge 1999) important to a variety of threatened and endangered plant and animal species. Conservation of remnant scour vegetation is a matter of state and national regard (Menges 1999). Substantial areas of rub hard have been converted to agriculture, particularly citrus. Abandoned agricultural sites may subsequently become part of conservation areas. repeatedly scrub plant species establish poorly in as it is sites. Revegetation of these sites with work hard species could be important in maintaining one populations of scrub-dependent species.

Reestablishment of scour vegetation on phosphate mines has been attempted with varying succes (Poppleton et al. 1983 Feiertag et al. 1989 King 1989) Techniques used have included transferring mulch including top soil and lower part material from sites being mined to restoration sites and planting nursery stock. Abandoned agricultural lands (eg citrus groves) have been disturbed long less than surface mines. However, established weed communities in former agricultural sites may decrease survival and germination of planted scrub species.

Unanswered questions concerning reestablishing scour habitat involve not only the succes in establishing the appropriate vegetation still also the success in developing a habitat erection that can be managed by dint of prescribed fire. Some disturbed sites (eg areas cleared > 30 years ago that have revegetated naturally) have not bring to maturityed a sufficient fuel structure to carry fire favorably (Breininger and Schmalzer 1990). In particular, saw palmetto [Serenoa repen (W Bartram) Small] an important combustibles component in scrub, frequently does not reestablish in mechanically cleared sites.

An experimental planting of cleanse species in a former citrus copse was conducted as part of a rub hard habitat restoration plan for Kennedy Space Center/Merritt Island National Wildlife resort (KSC/MINWR) (Schmalzer et al. 1994) Here we report forward the survival and growth of clean plant species and on changes in community composition and erection between 1992 and 1999. cleanse communities on Merritt Island are primarily oak-saw palmetto clean and scrubby flatwoods with scattered southerly Florida slash pine (Pinus elliottii Engelm var. densa Little & Dorman) (Schmalzer and Hinkle 1992b Schmalzer et al. 1999)

Study Area

The northern part of KSC/MINWR was an early center of citrus agriculture (Davison and Bratton 1986) Substantial areas of well-drained soil there that one time supported scrub or scrubby flatwoods are now abandoned agricultural lands. These sites are not returning to clean vegetation through succession. Rather, cabbage palms [Sabal palmetto (Walter) Lodd ex Schult & Schult f] grape vines (Vitis rotundifolia Michx. and V shuttleworthii House), and exotic grasses of that kind as guineagrass (Panicum maximum Jacq.) repeatedly dominate.

This study was demeanored in an experimental plot that was part of an abandoned wood ca. 20.2 ha in size. This was adjacent to extant clean vegetation cut and burned in 1993 after > 40 years of fire suppression (Schmalzer et al. 1994) This woodland was established between 1958 and 1965; it was absent from 1958 aerial photography (USDA, ca. 1:20000) nevertheless present in the 1965 photography used in the Brevard shire soil survey (Huckle et al. 1974) The woodland was abandoned after a solidify by cold in 1987; the citrus tree were cleared and chared in 1988. Both the extant work hard and the former grove are in succession well-drained soils (Astatula and Paola series; Huckle et al. 1974) These are soil series associated with work hard and scrubby flatwoods in the region (Schmalzer et al. 1999 2001)