Enhancing the Farm Bill's Conservation Potential Through Land Prioritization

ABSTRACT The Farm Bill conservation programs serve as the primary tools for the creation and improvement of wildlife habitat on working lands. Wildlife conservation would benefit from a working land-prioritization system that integrates these programs. We developed a Geographic Information System (GIS)–based system to prioritize land for inclusion in Farm Bill conservation programs. We designed the system to be applicable throughout the United States, to minimize potential conflicts of interest, and to facilitate simple implementation. We designated high conservation value (HCV) lands using habitats of greatest conservation need. We placed priority zones around HCV lands to determine high- and low-priority working lands. Nationwide implementation of this system would require gathering and manipulating data from multiple sources, as well as creation of a GIS layer denoting locations of working lands currently in conservation programs. This system would allow funding to be maximized through the ability to select participation based on property location and size, and to target landowners for participation. The wide-ranging potential benefits of this system make it well-suited for serving as the backbone to conservation on working lands.     

Similarities between l-Phenylalanine and m-Fluorophenylalanine as Substrates for l-Phenylalanine Ammonia-Lyase

The ability of l -phenylalanine ammonia-lyase (E.C. 4.3.1.5) to metabolize dl -m-, dl -o- and dl -p-fluorophenylalanine in Avena sativa has been examined. Although all three amino acid analogues served as substrates for this enzyme, there was a marked difference in the behavior of the meta isomer from that of the para and ortho species. The Michaelis constant for the meta analogue was similar to that obtained for the natural substrate, l -phenylalanine, but distinct from the kinetic data for the para and ortho isomers. In addition, in vivo analyses demonstrated that both l -phenylalanine and the meta-fluoro-derivative served to protect against chlorogenic acid loss, whereas previous studies have shown that the para and ortho species depressed levels of this phenolic derivative. Finally, treatment of coleoptile apices with either the meta isomer or l -phenylalanine reversed dl -p-fluorophenylalanine stimulated growth and attendant reduction in chlorogenic acid content. These findings provide further clarification of the effects of fluorophenylalanines upon l -phenylalanine ammonia-lyase mediated biosynthesis of low molecular weight phenols in Avena.     

Spatio-Temporal Factors Shaping Diurnal Space Use by Pygmy Rabbits

Abstract: Factors influencing patterns of space use by pygmy rabbits (Brachylagus idahoensis) are poorly understood. We studied diurnal space use by adult pygmy rabbits during multiple breeding and nonbreeding seasons at 3 sites in the Lemhi Valley, Idaho, USA, during 2004–2005. Pygmy rabbits used larger areas than predicted by allometric models and documented by some previous investigations. Sex and season strongly influenced space use by rabbits. Males used larger home ranges and core areas, more burrow systems, and more widely dispersed burrow systems than did female rabbits. We also documented significant differences among study sites in many movement parameters, which suggested that local resource distribution also might influence how pygmy rabbits use space. Our results indicated that pygmy rabbits use large areas and exhibit seasonal, sex, and site-specific variation in patterns of movement and space use. Therefore, larger areas of habitat may be needed to conserve pygmy rabbits to accommodate seasonal, regional, and potentially annual variation in resource availability and to maintain linkages among populations.     

Patterns of genetic structure in the endangered aquatic gastropod Valvata utahensis (Mollusca: Valvatidae) at small and large spatial scales

1. The aquatic snail Valvata utahensis (Gastropoda: Valvatidae) is a federally endangered aquatic mollusk known only from the Snake River in southern Idaho, U.S.A. The Snake River, like many other large river systems in the western United States, has undergone substantial anthropogenic modifications in recent history that have altered water flows, changed physicochemical attributes of the water and produced an overall spatially fragmented aquatic system. 2. Because little is currently known about the basic biology and life history of V. utahensis, we conducted a detailed genetic analysis of amplified fragment length polymorphism (AFLP) and mitochondrial DNA sequence variation in this species from six locations along the Snake River. This study was designed to discern (i) levels of within‐location genetic diversity, (ii) patterns of genetic structure at small spatial scales (i.e. within sampling locations) and (iii) patterns of genetic structure at large spatial scales (among sampling locations). 3. We show that comparable levels of nuclear genetic variation exist within each of the six locations examined. However, reduced mitochondrial sequence diversity was observed at Thousand Springs compared with the other locations examined. 4. We further illustrate that V. utahensis shows no genetic structure within locations over relatively small physical distances up to approximately 3 km. We suggest that active dispersal of individuals via crawling and passive dispersal because of downstream displacement or floating behaviours may have produced this pattern. However, at large spatial scales genetic structure generally followed an isolation‐by‐distance pattern. This pattern was not directly correlated with the connectivity of locations through the river corridor and suggested the possible role of episodic passive dispersal via avian waterfowl or the effects of historical floods throughout the Snake River c. 14 000 years ago.     

Hormonal Changes Associated with Growth and Development of Red Raspberries

Analysis for gibberellin-like substances (GA) and cytokinins in cold and non-cold treated fall-bearing and cold treated June-bearing cultivars of red raspberries (Rubus idaeus L.) was made at the 10 and 20 node stages of growth (at 10 nodes, all plants were vegetative; at 20 nodes, only cold treated plants of fall-bearing cultivars were flower induced). Quantitative changes in GAs, as analyzed by the lettuce hypocotyl bioassay, were observed only in flower induced plants. In fall-bearing cultivars at the 20 node stage of growth, there was a 100% greater activity in cold than non-cold treated plants. Likewise, cold treated plants had a 60% greater activity at the 20 than at the 10 node stage of growth. Major qualitative differences in GAs were observed between the 10 and 20 node stage of growth in cold treated fall-bearing cultivars but not in cold treated plants of June-bearing cultivars. Changes in compounds at R_f 0.3 and 0.5 accounted for 35 to 54% of the total increase in GA activity between flower induced and non-induced stages of growth. Cytokinin activity tested by the tobacco callus bioassay was greater at the 20 than at the 10 node stage of growth in all cultivars and treatments. However, cold treated plants of the fall-bearing type had 70% greater cytokinin activity than non-cold treated plants at both stages of growth. It is suggested that gibberellins, possibly acting synergistically with cytokinins, are involved inflower induction in red raspberries.     

Soil type links microbial colonization of rice roots to methane emission

Most of the methane (CH₄) emission from rice fields is derived from plant photosynthates, which are converted to CH₄. Rice cluster I (RC-1) archaea colonizing the rhizosphere were found to be the methanogens responsible for this process. Hence, RC-1 methanogens seem to play a crucial role in emission of the greenhouse gas CH₄. We determined the community composition and activity of methanogens colonizing the roots of eight different rice cultivars after growth on both Italian rice soil and river bank soil, which contained different communities of methanogenic archaea. The community composition was analyzed by terminal restriction fragment length polymorphism and cloning/sequencing of the archaeal 16S rRNA gene and the mcrA gene coding for a subunit of the methyl coenzyme M reductase. When grown on rice field soil, the methanogenic community of the different rice cultivars was always dominated by RC-1 methanogens. In contrast, roots were colonized by Methanomicrobiales when grown on river bank soil, in which RC-1 methanogens were initially not detectable. Roots colonized with Methanomicrobiales compared with RC-1 exhibited lower CH₄ production and CH₄ emission rates. The results show that the type of methanogens colonizing rice roots has a potentially important impact on the global CH₄ cycle.     

The endemic molluscs of the Late Miocene Lake Pannon: their origin, evolution, and family-level taxonomy

Long-lived lakes are often sites of spectacular endemic radiations. During the Oligocene to recent history of the Paratethys, large, long-lived (more than a million years) lakes with endemic faunas formed three times, in three different basins: the first in the Pannonian basin, the second in the Euxinian (Black Sea) basin, and the third in the Caspian basin. Because the Euxinian lake inherited much of the fauna of Lake Pannon, the three lakes together hosted two endemic radiations of molluscs. The most long-lived lake in the region was Lake Pannon, which persisted approximately seven million years from the late Middle Miocene to the Early Pliocene. Lake Pannon was formed by isolation from the sea. Changes in hydrological regime and/or water chemistry in addition to the relative lowstand which accompanied (or caused) the isolation almost completely exterminated the restricted marine fauna of the basin. A few highly euryhaline and marginal marine cardiids, dreissenids, and hydrobiids survived this environmental change. As in other fossil and extant long-lived lakes, the originally low-diversity fauna radiated into a high number of related endemic species (‘species flocks’) and genera in the expanding and ecologically vacated lake. Many originally freshwater taxa (unionids, sphaeriids, viviparids, valvatids, melanopsids, lymnaeids, planorbids) entered the lake as well, and some of them also gave rise to endemic clades. Evolution in both relict and freshwater immigrant groups led to the appearance of highly unusual shell shapes. Many lineages exhibit gradual morphological changes over one to several million years. More than 900 endemic mollusc species have been described from Lake Pannon, although this number includes junior synonyms, invalid species names, and highly similar chronospecies. Applying a conservative taxonomy, all these species belong to four bivalve and eight gastropod families. The high degree of endemism, however, is reflected by proposals of some authors to establish as many as five new families based on Lake Pannon endemics.