Those who have tried to restore viable self-sustaining populations to the wild are left with a se... more Those who have tried to restore viable self-sustaining populations to the wild are left with a sense of humility and wonder at the complexity of ecological systems. Although restoration may have a deceiving appearance of simplicity, many early attempts at restoring populations met with low success (examples in Falk et al. 1996) or have not been monitored long enough to know their status (Dalrymple et al. 2012). Experience has taught us that establishing viable, self-sustaining populations—one of the stated objectives of restoration ecology—can be extraordinarily difficult and require a great deal of time (Albrecht et al. 2011).
This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants ... more This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants of herbivore-modified architecture, (c) consequences for herbivores of herbivore-modified architecture, and (d) the relationship between herbivore impacts on plant ...
This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants ... more This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants of herbivore-modified architecture, (c) consequences for herbivores of herbivore-modified architecture, and (d) the relationship between herbivore impacts on plant ...
Hybridization may threaten the conservation status of rare species through genetic assimilation a... more Hybridization may threaten the conservation status of rare species through genetic assimilation and may confound the ability to distinguish among taxa. We studied these issues in an endangered shrub, Purshia subintegra (Rosaceae), known from four populations growing on limestone outcrops in central Arizona (USA). Using amplified fragment length polymorphisms (AFLP) and the Bayesian clustering algorithm implemented in STRUCTURE, we identified
Central to the conservation of the federally endangered Purshia subintegra (Arizona cliffrose) is... more Central to the conservation of the federally endangered Purshia subintegra (Arizona cliffrose) is development of an understanding of its cultivation requirements. This knowledge will enable us to augment declining or threatened populations as well as preserve genotypes impacted by human activities. We studied seed and stem cutting propagation of P. subintegra. The highest success rate for rooted stem cuttings of P. subintegra that were collected wild was 34 percent. The stem cuttings of P. subintegra survived best when they were taken in the fall, rooted in perlite with Hormex 8, and watered once daily. Stem cuttings can take from 1 to 11 months to root depending on treatment and time of cutting. Propagation from seed was much more successful (88%) when we used fresh seed sown in perlite with cold stratification for 4 weeks. Seeds did not require native soil to germinate, nor did seedlings require native soil to survive. This means that P. subintegra can propagate and survive under ...
Of the 2329 plant species that are native to Puerto Rico, 188 are grasses (Poaceae) and nearly 20... more Of the 2329 plant species that are native to Puerto Rico, 188 are grasses (Poaceae) and nearly 20% of those are critically imperiled. To address gaps in knowledge of US endangered Aristida chaseae (Chase’s Threeawn) and Aristida portoricensis (Pelos del Diablo) from Sierra Bermeja in southwestern Puerto Rico, we conducted experiments to determine viability of seeds produced in the wild, germination requirements, and ability to be stored under cold, dry conditions. Both species produced low proportions of viable seed in the wild (Chase’s Threeawn: <7%, Pelos del Diablo: 34%); seeds germinated at higher rates when desiccated than when fresh or desiccated and frozen. Mean time to germination was slow in both species: 86 d for fresh Pelos del Diablo and 50 d for Chase’s Threeawn. Mean germination time in Chase’s Threeawn slowed to over 90 d in drying and freezing treatments, while these treatments increased the rate of germination in Pelos del Diablo seeds. Both taxa can grow well and produce seed when grown in containers with well-drained soils; therefore, growing plants for restoration is possible. Both species’ seeds can be dried and stored at freezing temperatures, at least for the short term. The longevity of these species’ seeds held in frozen storage is unknown; thus, we advise further testing of seeds after 3, 5, and 10 y in frozen storage.
Those who have tried to restore viable self-sustaining populations to the wild are left with a se... more Those who have tried to restore viable self-sustaining populations to the wild are left with a sense of humility and wonder at the complexity of ecological systems. Although restoration may have a deceiving appearance of simplicity, many early attempts at restoring populations met with low success (examples in Falk et al. 1996) or have not been monitored long enough to know their status (Dalrymple et al. 2012). Experience has taught us that establishing viable, self-sustaining populations—one of the stated objectives of restoration ecology—can be extraordinarily difficult and require a great deal of time (Albrecht et al. 2011).
This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants ... more This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants of herbivore-modified architecture, (c) consequences for herbivores of herbivore-modified architecture, and (d) the relationship between herbivore impacts on plant ...
This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants ... more This chapter focuses on (a) how herbivores alter plant architecture, (b) consequences for plants of herbivore-modified architecture, (c) consequences for herbivores of herbivore-modified architecture, and (d) the relationship between herbivore impacts on plant ...
Hybridization may threaten the conservation status of rare species through genetic assimilation a... more Hybridization may threaten the conservation status of rare species through genetic assimilation and may confound the ability to distinguish among taxa. We studied these issues in an endangered shrub, Purshia subintegra (Rosaceae), known from four populations growing on limestone outcrops in central Arizona (USA). Using amplified fragment length polymorphisms (AFLP) and the Bayesian clustering algorithm implemented in STRUCTURE, we identified
Central to the conservation of the federally endangered Purshia subintegra (Arizona cliffrose) is... more Central to the conservation of the federally endangered Purshia subintegra (Arizona cliffrose) is development of an understanding of its cultivation requirements. This knowledge will enable us to augment declining or threatened populations as well as preserve genotypes impacted by human activities. We studied seed and stem cutting propagation of P. subintegra. The highest success rate for rooted stem cuttings of P. subintegra that were collected wild was 34 percent. The stem cuttings of P. subintegra survived best when they were taken in the fall, rooted in perlite with Hormex 8, and watered once daily. Stem cuttings can take from 1 to 11 months to root depending on treatment and time of cutting. Propagation from seed was much more successful (88%) when we used fresh seed sown in perlite with cold stratification for 4 weeks. Seeds did not require native soil to germinate, nor did seedlings require native soil to survive. This means that P. subintegra can propagate and survive under ...
Of the 2329 plant species that are native to Puerto Rico, 188 are grasses (Poaceae) and nearly 20... more Of the 2329 plant species that are native to Puerto Rico, 188 are grasses (Poaceae) and nearly 20% of those are critically imperiled. To address gaps in knowledge of US endangered Aristida chaseae (Chase’s Threeawn) and Aristida portoricensis (Pelos del Diablo) from Sierra Bermeja in southwestern Puerto Rico, we conducted experiments to determine viability of seeds produced in the wild, germination requirements, and ability to be stored under cold, dry conditions. Both species produced low proportions of viable seed in the wild (Chase’s Threeawn: <7%, Pelos del Diablo: 34%); seeds germinated at higher rates when desiccated than when fresh or desiccated and frozen. Mean time to germination was slow in both species: 86 d for fresh Pelos del Diablo and 50 d for Chase’s Threeawn. Mean germination time in Chase’s Threeawn slowed to over 90 d in drying and freezing treatments, while these treatments increased the rate of germination in Pelos del Diablo seeds. Both taxa can grow well and produce seed when grown in containers with well-drained soils; therefore, growing plants for restoration is possible. Both species’ seeds can be dried and stored at freezing temperatures, at least for the short term. The longevity of these species’ seeds held in frozen storage is unknown; thus, we advise further testing of seeds after 3, 5, and 10 y in frozen storage.
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