Red spruce forests have declined considerably throughout their range in the past decades. As agri... more Red spruce forests have declined considerably throughout their range in the past decades. As agricultural fields are abandoned and land becomes available for reforestation, the possibility arises for red spruce forests to expand onto them. This study addresses the potential for red spruce forests to expand onto adjacent old fields in Greenwich, Prince Edward Island National Park, Canada. We examined red spruce distribution and abundance, plant species diversity and changes in community composition along a gradient from the interior of red spruce forests out towards the centre of adjacent old fields. Examining the patterns of red spruce distribution and abundance revealed that, where cultivation and logging have been abandoned recently in the fields and forests, regeneration is limited to the forest stands, but in the sites with older fields and forests, regeneration extends into and is more vigorous in the fields. Although species diversity varied from forest to field only for the tree and shrub layers, important changes occurred in the ground species composition. There is no evidence yet that the herbaceous species present in the forest stands will colonise the old fields. The results suggest that both environmental differences among sites and length of time since the fields were abandoned explain red spruce regeneration patterns. In order to more accurately assess the potential for red spruce regeneration in old fields, long-term monitoring of the production, dispersal and viability of red spruce seeds from adjacent forests and of the constraints to seedling establishment and survival in old fields will be needed.
Red spruce forests have declined considerably throughout their range in the past decades. As agri... more Red spruce forests have declined considerably throughout their range in the past decades. As agricultural fields are abandoned and land becomes available for reforestation, the possibility arises for red spruce forests to expand onto them. This study addresses the potential for red spruce forests to expand onto adjacent old fields in Greenwich, Prince Edward Island National Park, Canada. We examined red spruce distribution and abundance, plant species diversity and changes in community composition along a gradient from the interior of red spruce forests out towards the centre of adjacent old fields. Examining the patterns of red spruce distribution and abundance revealed that, where cultivation and logging have been abandoned recently in the fields and forests, regeneration is limited to the forest stands, but in the sites with older fields and forests, regeneration extends into and is more vigorous in the fields. Although species diversity varied from forest to field only for the tree and shrub layers, important changes occurred in the ground species composition. There is no evidence yet that the herbaceous species present in the forest stands will colonise the old fields. The results suggest that both environmental differences among sites and length of time since the fields were abandoned explain red spruce regeneration patterns. In order to more accurately assess the potential for red spruce regeneration in old fields, long-term monitoring of the production, dispersal and viability of red spruce seeds from adjacent forests and of the constraints to seedling establishment and survival in old fields will be needed.
Red spruce can establish on abandoned agricultural land only from seed, unlike in logged environm... more Red spruce can establish on abandoned agricultural land only from seed, unlike in logged environments where red spruce forests can establish from seedlings that survived the harvest. In this study we collected seeds from the seed rain and from soil cores to examine the abundance and distribution of the red spruce seed rain and the seed bank along a gradient from the forest interior to adjacent old fields in Greenwich, Prince Edward Island National Park (PEINP), Canada. In addition, we examined the temporal abundance and distribution of the seed rain through the seed-fall season. We subsequently tested the germination potential of red spruce seeds from the forest portion of our sites. Because red spruce seeds are usually viable for only one year, we expected the seed bank to be either very small or non-existent. We found 39 red spruce seeds in the seed bank, distributed over 13.1% of the sampled area; 37 of these seeds were definitely nonviable. From the seed rain, we collected 224 red spruce seeds, distributed over 29.4% of the sampled area; 213 of these seeds were definitely nonviable. Nearly all of the red spruce seed rain fell within the forest; differences in abundance among collection dates were not statistically significant. Our seeds had a low germination rate of 0.004%, in part because red and black spruce commonly hybridise in our study area. Despite the low rates of red spruce seed dispersal and viability, the presence of red spruce saplings in our two longest-abandoned fields shows that the species is able to slowly colonise some old fields in PEINP.
Red spruce forests have declined considerably throughout their range in the past decades. As agri... more Red spruce forests have declined considerably throughout their range in the past decades. As agricultural fields are abandoned and land becomes available for reforestation, the possibility arises for red spruce forests to expand onto them. This study addresses the potential for red spruce forests to expand onto adjacent old fields in Greenwich, Prince Edward Island National Park, Canada. We examined red spruce distribution and abundance, plant species diversity and changes in community composition along a gradient from the interior of red spruce forests out towards the centre of adjacent old fields. Examining the patterns of red spruce distribution and abundance revealed that, where cultivation and logging have been abandoned recently in the fields and forests, regeneration is limited to the forest stands, but in the sites with older fields and forests, regeneration extends into and is more vigorous in the fields. Although species diversity varied from forest to field only for the tree and shrub layers, important changes occurred in the ground species composition. There is no evidence yet that the herbaceous species present in the forest stands will colonise the old fields. The results suggest that both environmental differences among sites and length of time since the fields were abandoned explain red spruce regeneration patterns. In order to more accurately assess the potential for red spruce regeneration in old fields, long-term monitoring of the production, dispersal and viability of red spruce seeds from adjacent forests and of the constraints to seedling establishment and survival in old fields will be needed.
Red spruce forests have declined considerably throughout their range in the past decades. As agri... more Red spruce forests have declined considerably throughout their range in the past decades. As agricultural fields are abandoned and land becomes available for reforestation, the possibility arises for red spruce forests to expand onto them. This study addresses the potential for red spruce forests to expand onto adjacent old fields in Greenwich, Prince Edward Island National Park, Canada. We examined red spruce distribution and abundance, plant species diversity and changes in community composition along a gradient from the interior of red spruce forests out towards the centre of adjacent old fields. Examining the patterns of red spruce distribution and abundance revealed that, where cultivation and logging have been abandoned recently in the fields and forests, regeneration is limited to the forest stands, but in the sites with older fields and forests, regeneration extends into and is more vigorous in the fields. Although species diversity varied from forest to field only for the tree and shrub layers, important changes occurred in the ground species composition. There is no evidence yet that the herbaceous species present in the forest stands will colonise the old fields. The results suggest that both environmental differences among sites and length of time since the fields were abandoned explain red spruce regeneration patterns. In order to more accurately assess the potential for red spruce regeneration in old fields, long-term monitoring of the production, dispersal and viability of red spruce seeds from adjacent forests and of the constraints to seedling establishment and survival in old fields will be needed.
Red spruce can establish on abandoned agricultural land only from seed, unlike in logged environm... more Red spruce can establish on abandoned agricultural land only from seed, unlike in logged environments where red spruce forests can establish from seedlings that survived the harvest. In this study we collected seeds from the seed rain and from soil cores to examine the abundance and distribution of the red spruce seed rain and the seed bank along a gradient from the forest interior to adjacent old fields in Greenwich, Prince Edward Island National Park (PEINP), Canada. In addition, we examined the temporal abundance and distribution of the seed rain through the seed-fall season. We subsequently tested the germination potential of red spruce seeds from the forest portion of our sites. Because red spruce seeds are usually viable for only one year, we expected the seed bank to be either very small or non-existent. We found 39 red spruce seeds in the seed bank, distributed over 13.1% of the sampled area; 37 of these seeds were definitely nonviable. From the seed rain, we collected 224 red spruce seeds, distributed over 29.4% of the sampled area; 213 of these seeds were definitely nonviable. Nearly all of the red spruce seed rain fell within the forest; differences in abundance among collection dates were not statistically significant. Our seeds had a low germination rate of 0.004%, in part because red and black spruce commonly hybridise in our study area. Despite the low rates of red spruce seed dispersal and viability, the presence of red spruce saplings in our two longest-abandoned fields shows that the species is able to slowly colonise some old fields in PEINP.
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