SLIDES: Recommended Best Management Practices for Plants of Concern: Practices Developed to Reduce the Impacts of Oil and Gas Development Activities to Plants of Concern

Presenter: Brian Kurzel, Colorado Natural Areas Program (CNAP) 27 slide

Aquilegia, Vol. 38 No. 1, Spring 2014, Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1147/thumbnail.jp

Aquilegia, Vol. 32 No. 4, Winter 2008, Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1126/thumbnail.jp

Aquilegia, Vol. 34 No. 2, Summer 2010, Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1132/thumbnail.jp

Aquilegia, Vol. 33 No. 2, Summer 2009, Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1128/thumbnail.jp

Aquilegia, Vol. 34 No. 1, Spring 2010, Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1131/thumbnail.jp

Lianas Suppress Seedling Growth and Survival of 14 Tree Species in a Panamanian Tropical Forest

Lianas are a common plant growth form in tropical forests, where they compete intensely with trees, decreasing tree recruitment, growth, and survival. If the detrimental effects of lianas vary significantly with tree species identity, as is often assumed, then lianas may influence tree species diversity and community composition. Furthermore, recent studies have shown that liana abundance and biomass are increasing relative to trees in neotropical forests, which will likely magnify the detrimental effects of lianas and may ultimately alter tree species diversity, relative abundances, and community composition. Few studies, however, have tested the responses of multiple tree species to the presence of lianas in robust, well‐replicated experiments. We tested the hypotheses that lianas reduce tree seedling growth and survival, and that the effect of lianas varies with tree species identity. We used a large‐scale liana removal experiment in Central Panama in which we planted 14 replicate seedlings of 14 different tree species that varied in shade tolerance in each of 16 80 × 80 m plots (eight liana‐removal and eight unmanipulated controls; 3136 total seedlings). Over a nearly two‐yr period, we found that tree seedlings survived 75% more, grew 300% taller, and had twice the aboveground biomass in liana‐removal plots than seedlings in control plots, consistent with strong competition between lianas and tree seedlings. There were no significant differences in the response of tree species to liana competition (i.e., there was no species by treatment interaction), indicating that lianas had a similar negative effect on all 14 tree species. Furthermore, the effect of lianas did not vary with tree species shade tolerance classification, suggesting that the liana effect was not solely based on light. Based on these findings, recently observed increases in liana abundance in neotropical forests will substantially reduce tree regeneration, but will not significantly alter tropical tree species diversity, relative abundance, or community composition

Restoration of the iconic Pando aspen clone: emerging evidence of recovery

Quaking aspen (Populus tremuloides Michx.) is being stressed across the America West from a variety of sources including drought, herbivory, fire suppression, development, and past management practices. Rich assemblages of plants and animals that utilize aspen forests, as well as economic values of tourism, grazing, hunting, and water conservation, make aspen ecosystems among the most valuable vegetation types in this region. The 43-ha Pando clone near Fish Lake, Utah, is an iconic example of an aspen community undergoing rapid decline due to overstory mortality and chronic recruitment failure. As part of a larger project to restore Pando, we fenced, treated, and monitored a portion of this famous grove with the intent of documenting regeneration responses and using such practices at larger scales. Twenty-seven randomly stratified monitoring plots were placed across this landscape in order to better understand herbivory and regeneration responses to distinct treatment categories: protected and unprotected, and passive (fenced only) and active (burning, shrub removal, selective overstory cutting) treatments. At each site, we measured basal area and mortality on mature trees, made counts of juvenile and intermediate suckers, documented browse levels and herbivore scat presence, and characterized environmental conditions in terms of aspen and common juniper cover, treatment type, elevation, slope, and aspect. Our results confirmed a positive regeneration response to browsing cessation after fencing, whereas non-fenced areas showed no improvement. Within the fence, there was a significantly better response of active treatment vs. passive and there was no significant difference between treatment types in terms of level of regeneration. Both active and passive management produced regeneration levels that were sufficient to replace dying canopy trees if managers continue to protect suckers until they exceed the reach of browsers. These results support a growing body of research suggesting managers need to invest in continuous protection from herbivory in stable aspen forests, as well as targeting additional post-treatment protection, to ensure adequate regeneration. We examine ramifications of these results for broader restoration purposes in the remainder of Pando, as well as other aspen communities regionally, with the ultimate goal of restoring ecological process toward greater ecosystem resilience

Annual Rainfall and Seasonality Predict Pan-tropical Patterns of Liana Density and Basal Area

We test the hypotheses proposed by Gentry and Schnitzer that liana density and basal area in tropical forests vary negatively with mean annual precipitation (MAP) and positively with seasonality. Previous studies correlating liana abundance with these climatic variables have produced conflicting results, warranting a new analysis of drivers of liana abundance based on a different dataset. We compiled a pan-tropical dataset containing 28,953 lianas (≥2.5 cm diam.) from studies conducted at 13 Neotropical and 11 Paleotropical dry to wet lowland tropical forests. The ranges in MAP and dry season length (DSL) (number of months with mean rainfall <100 mm) represented by these datasets were 860–7250 mm/yr and 0–7 mo, respectively. Pan-tropically, liana density and basal area decreased significantly with increasing annual rainfall and increased with increasing DSL, supporting the hypotheses of Gentry and Schnitzer. Our results suggest that much of the variation in liana density and basal area in the tropics can be accounted for by the relatively simple metrics of MAP and DSL.Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btpPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78581/1/j.1744-7429.2009.00589.x.pd