Factors determining species richness of soil seed banks in lowland ancient woodlands

Abstract

The demise of coppicing in UK ancient woodlands, combined with the planting of non-native, fast-growing conifers in the twentieth century, heightens the potential recharge value of ground flora seed banks. Soil cores from adjoining semi-natural and conifer-containing stands in four lowland ancient woods in central England were removed to establish seed bank species richness. During a fourteen-month germination trial soil from two depths yielded 6554 seedlings from 81 species, ten of which showed a strong affinity for ancient woodland conditions. Juncus effusus accounted for 80 of emergent seeds whilst 23 other species, including Lysimachia nummularia and Potentilla sterilis, were represented by only one individual. Species richness is described by a model that explains 40 of observed variance (P < 0.00001). The model has three significant variables: species richness increases as soil pH rises, and decreases with both depth and increasing time since the most recent planting/disturbance event. No difference was found in the density of seeds from species common to paired semi-natural and conifer-containing stands that were separated only by a woodland ride, suggesting prior management and environmental conditions have a greater influence on seed banks than current stand type. Sørensen similarity index values revealed poor congruence between above-ground vegetation and species in the seed bank. Taking pH measurements in conifer stands identified as younger in terms of planting/disturbance may help locate areas where greater numbers of species (including woodland specialists) are located. Caution is required, however, as these seed banks may also contain non-target, competitive species that may swamp the regeneration of woodland specialists. © 2010 Springer Science+Business Media B.V

Edges, exotics and deer: the seed bank of a suburban secondary successional temperate deciduous forest

“…; Erenler et al. ). Fifty seed bank species were native and 22 were exotic (excluding merged genera).…”

“…; Hopfensperger ; Bossuyt & Honnay ; Erenler et al. ), but less is known about seed banks of urban and suburban forests (Kostel‐Hughes & Young ; King & Buckney ; Fisher et al. ) and how increased pressure from exotic species, edge effects and deer may impact the seed bank.…”

Consistent seed bank spatial structure across semi‐natural habitats determines plot sampling

“…in forest: four 25 cm 2 core samples in a 2 m × 2 m plot (0.2% of the plot surface area sampled; Erenler et al. ); in grassland: 20 4.9 cm 2 core samples in a 1 m × 1 m plot (1% of the plot surface area sampled; Jacquemyn et al. ) or in heathland: 25 19.6 cm 2 core samples in a 100 m 2 plot, collected at an intensity of five 19.6 cm 2 core samples per 1 m × 1 m quadrat (1% of the plot surface area sampled; Måren & Vandvik ).…”

Open Structured Woodland and the Ecological Interpretation of Scotland's Ancient Woodland Inventory

“…Decisions during map making, and in the quantification of mapped resources, may have different implications for species groups with different ecologies. On the one hand, a clearly defined Class 3 AWI site (Level 0 in our study) represents a break in woodland continuity; if sufficiently brief, the site may still retain soil properties (Wilson et al 1997;Verheyen et al 1999) or seed banks (Erenler et al 2010) useful to the regeneration/restoration of ancient woodland. On the other hand, such a break in continuity can represent a complete hiatus for tree-dependent organisms including certain epiphytic lichens or invertebrates.…”

“…This can be particularly important for organisms which are dependent on the occurrence of trees themselves, such as epiphytes. Tree-dependent species may not survive in situ a period of clear-felling, for example, as is possible for vascular plants in a seed bank (Erenler et al 2010). This dependency makes Class 3 woodlands especially significant, because the inferred break in continuity (cf.…”