ruderal

Of the spontaneous alien species 64% can be grown culturally (for human and animal food, as ornamental plants), the rest have been brought to Tallinn accidentally through human activity (ruderals).

decumbens) which have a short-term seed bank, weakly significant for ruderals from the Asteraceae and Rubiaceae with a more constant seed bank, and absent for the Melastomataceae with a persistent seed bank.

Many higher elevation ruderals of the Ru'us al-Jibal are

Significant values of ruderals and meadow/pasture plant pollen, as well as Poaceae pollen, refer to relatively open landscape in the area.

As regards plant strategy types, generalists (CSR-strategy), stress-tolerant species, and ruderals were dominant in the herbaceous vegetation (Table 2).

and rye (Secale cereale) from cultural plants; Plantago major/media, Plantago lanceolata t., rosebay willowherb (Epilobium angustifolium), thistle (Cirsium t.) and Artemisia which belong to weeds and ruderals; wetlands taxa as common valerian (Valeriana officinalis), Orchidaceae, Liliaceae and Iridaceae.

This is surprising because ruderals dominate the soil seed bank in both meadows (Lang and Halpern, 2007) and forests in this region (Kellman, 1970; Halpern et al., 1999) and are abundant after large-scale disturbance (e.g., Schoonmaker and McKee, 1988; Halpern, 1989).

The plant life histories that evolved under these circumstances he labelled ruderals, competitors and stress tolerators.

Still, the increased proportion of ruderals, especially Urtica, is significant.

The first axis separates native dominant and late seral species plots, at the positive end of the axis, from introduced ruderal species plots at the negative end of the axis and native ruderals at just above zero (Fig.

But the intermediate group, stress-tolerant ruderals (S-R), is represented by Acer campestre, Malus sylvestris, Pyrus communis, Prunus padus, and Prunus avium.