Summary Ecological restoration is critical for mitigating habitat loss and providing ecosystem services. However, restorations often have lower diversity than remnant, reference sites. Phylogenetic diversity is an important component of biodiversity and ecosystem function that has only recently been used to evaluate restoration outcomes. To move towards prediction in the restoration of biodiversity, it is necessary to understand how phylogenetic diversity of restorations compares with that of reference sites, and where deficits are found, to evaluate factors constraining phylogenetic diversity. We quantified plant taxonomic and phylogenetic diversity in eastern tallgrass prairie, one of the most endangered ecosystems on earth. We measured diversity at large (site) and small (plot) scales in 19 restored prairies and compared patterns with those from 41 remnant prairies. To evaluate how environmental conditions and management actions influence outcomes, we tested the effects of soil properties and seed mix composition on diversity of restorations. Restored prairies were less phylogenetically diverse than remnants at both spatial scales. On the other hand, the total species richness of remnant and restored prairies did not significantly differ, but remnants had higher native richness. Restored communities were taxonomically and phylogenetically distinct from remnants. Soil properties (moisture and pH) influenced phylogenetic diversity and composition. There were positive relationships between the taxonomic and phylogenetic diversity of seed mixes and resulting diversity of planted assemblages (excluding volunteer species). Species in seed mixes were more closely related than expected by chance, and several clades found in remnant prairies were missing from seed mixes. Synthesis and applications. Restored tallgrass prairies had lower phylogenetic diversity than remnant prairies, which may contribute to the widely observed phenomenon of restorations not being functionally equivalent to reference sites. It is encouraging for restoration efforts that seed mix phylogenetic diversity predicted phylogenetic diversity of planted assemblages. This indicates that designing phylogenetically diverse seed mixes for restoration is beneficial. In addition, clades found in reference sites that are missing from restoration seed mixes could be added to new or existing restorations to reduce gaps in phylogenetic diversity. Further work on the effects of management on phylogenetic diversity is needed to advance restoration of biodiversity.
Rodent caching is a significant factor in the establishment of Purshia tridentata in central Oregon pine forest. The pattern of cache placement is strongly influenced by pine litter patterns. As litter accumulates because of fire exclusion, desirable litter—free sites are becoming less abundant. As a result, a decline in Purshia populations may be expected.
This paper discusses the heritage variety with reference to: historical origin, mode of breeding, genetic diversity, local genetic adaptation, and association with traditional farming systems.
Management practices over the past 100 years, especially fire exclusion and suppression, in Yosemite Valley, Yosemite National Park, CA resulted in forest stands with basal areas in excess of 110 m 2 ha -1. Accelerated attack by several species of bark beetles (Scolytidae) followed a severe drought in 1976-77. Pinusponderosa, already under attack by root rot (Heterobasidion annosus) was affected severely, and mortality exceeded 70%. Calocedrus decurrens did not suffer comparable mortality and has replaced P. ponderosa as the dominant species. Size class distributions as well as comparisons of relative density and relative basal area from 1961, 1976 and 1983-85 also demonstrate a major change in forest composition. This change is most pronounced on alluvial landforms.
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