A. The importance of soil seed banks for the conservation of nearly extinct species: insights from Colenathus subtilis (Poaceae)

Pentingnya soil seed banks dan dinamikanya berguna untuk konservasi spesies yang dalam penelitian ini digunakan contoh Poaceae (Coleanthus subtilis).

Perbedaan pola distribusi dari tanaman yang terancam punah yang berada di bawah tanah sebagai soil seed bank vs vegetasi yang menjadi kanopi telah diinformasikan di Red Data books.

Seed banks berperan penting dalam program konservasi keragaman genetis dan restorasi alami untuk vegetasi basah yang dapat memperbaiki bahayanya punahnya spesies tanaman.

Has not been reported…. Salah satu karakteristik dari tanaman ini adalah kapasitas mereka yang bisa survive sebagai

soil seed bank selama kondisi yang tidak menguntungkan.

METODE:The bulked soil samples were analyzed using two methods (Bernhardt & Hurka, 1989; Bernhardt):1. Separating the organic fraction by washing and floating (sieving method) and than

recovery by sieving. Followed by counting the seeds under a microscope.2. Spread out of soil samples in the greenhouse and counting f germinated seeds and of the

seedlings identified (seedling emergence method).

Kita menemukan bahwa jumlah individu Coleanthus subtilis masih terepresentasikan dalam soil seed bank. Coleanthus masih hidup secara in situ dengan densitas yang tinggi sebagai soil seed bank dan kemudian menunjukkan kenampakan yang tinggi sebagai kanopi yang menutupi.

The number of seeds in soil seed bank is correlated with the soil type (BERNHARDT 1999): - Mud conserves viability of seeds for longer time and in deeper soil layers (anaerobic conditions) (Tab. 1)- Sandy substrate contain less number of seeds only in the upper soil layers (0-5 cm).

B. The Relationship between the soil seed bank and above-ground vegetation of a coastral barriers island kajian mengenai komunitas beberapa tanaman telah menunjukkan pentingnya soil seed bank

untuk perkembangan ekosistem mengikuti gangguan. Whether a seed bank is either transient or persistent (Thompson & Grime 1979) has been

proposed to be related to successional age and disturbance regime (Thompson 1978; Pierce & Cowling 1991a). However, the nature of this relationship is equivocal (Donelan & Thompson 1980; Pierce & Cowling 1991a), mainly because few studies compare the seed bank of a diversity

of habitats (although see Thompson & Grime 1979; Partridge 1989). Most seed bank studies consider a single habitat or plant community, e.g., grassland, forest, wetland (e.g. van der Valk & Davis 1978; Roach 1983; Matlack & Good 1990; Warr et al. 1994).

Studi ini menunjukkan bahwa sistem gundukan pesisir mungkinmengandung germinable bank benih tanah luas yang akanmenjadi penting dalam komunitas tumbuhan regenerasi setelah gangguan.

These vegetation types offered a contrast in successional age, landscape position, and disturbance frequency. The objectives of the study were to determine (1) the extent to which coastal dune plant communities possess a germinable soil seed bank, (2) the similarity between the composition of the soil seed bank and the above-ground flora, and (3) how differences in seed bank composition from different vegetation types are related to community stability and relative successional age. vegetasi ini

jenis yang ditawarkan kontras usia suksesi, lanskapposisi, dan frekuensi gangguan. Tujuanpenelitian ini adalah untuk mengetahui (1) sejauh manakomunitas tumbuhan gundukan pesisir memiliki suatu germinablebank benih tanah, (2) kesamaan antara komposisi-tion benih Bank tanah dan flora di atas tanah,dan (3) bagaimana perbedaan dalam komposisi bank benih darijenis vegetasi yang berbeda terkait dengan masyarakatstabilitas dan usia suksesi relatif.

METODE:It is likely that counts of germinating seedlings insamples under greenhouse conditions overestimates thefunctional contribution of the seed bank to seedlingrecruitment (Peart 1989). However, in large-scale sur-veys such as in this study it is not practical to make acomplete enumeration of soil-stored seed followed byseed viability tests. The direct germination procedureused here is efficacious, time efficient, and gives eco-logically meaningful estimates of the seed bank (Gross1990; Rothrock et al. 1993). This technique is particu-larly suitable for the detection of persistent seed banksin which component seeds are more than one year old(Thompson & Grime 1979). By contrast, transient seedsbanks are those in which none of the seed persists in aviable condition for more than one year (Thompson &Grime 1979). Although not exhaustive, our methodol-ogy involving samples from the autumn and followingspring allows a general distinction between these twotypes of seed bank to be made.Seedling totals are expressed

as field density per m2 and are summarized by life form.Differences in numbers of germinating seedlings ofeach species per vegetation type and sample date (autumn 1990 or spring 1991) were not tested statisticallybecause of the non-normal nature of the data, and thehigh frequency of zero seedlings per vegetation type foreach species (Warr et al. 1994).