Mountain Pine Beetle Presence Affects Nest Patch Choice of Red-Breasted Nuthatches

Abstract: The mountain pine beetle (Dendroctonus ponderosae) outbreak in western Canada poses significant conservation concern; thus, insights into its effects on wildlife habitat are essential. We used generalized linear mixed models to examine the influence of quaking aspen (Populus tremuloides) and mountain pine beetle—infected lodgepole pine (Pinus contortus) on nest patch selection of red-breasted nuthatches (Sitta canadensis) in central British Columbia, Canada. Prior to the outbreak, nuthatches selected nest patches with 64% more suitable nest trees (standing dead aspen, ≥12.5 cm dbh) than available (103 trees/ha vs. 63 trees/ha, respectively), but in outbreak years nuthatches chose nest patches with 37% more beetle-infected pine trees than available (63 trees/ha vs. 46 trees/ha, respectively). Our results suggest that nuthatches select sites that maximize nesting and foraging opportunities and, during food pulses, may trade off higher densities of suitable nest trees for higher densities of foraging trees. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):733–737; 2008)     

Photo-Identification of Sea Otters Using Nose Scars

Abstract: We evaluated the use of naturally occurring nose scars to identify individual sea otters (Enhydra lutris) in Simpson Bay, Prince William Sound, Alaska, USA. We spent 520 hours over 103 days conducting photo-identification surveys from June to August 2002 and 2003. Altogether, we identified 114 individuals. The number of sightings per individual ranged from 1 to 26, with an average of 3.3. The maximum number of sightings of an individual within a single year was 19. We saw 54 otters (47%)on >1 day, with an average of 8.1 sightings per individual for those seen more than once. We identified 8 individuals (19% of those identified in 2002) in both years. Males and otters of undetermined sex that we first sighted in June had the highest re-sighting rates. We considered 45% of all individuals encountered identifiable from nose scars. Nose scars were present in 63% (n = 19) of males, 45% (n = 45) of females, and 40% (n = 49) of otters of undetermined sex. Our results are similar to the results of photo-identification studies of other marine mammals, suggesting that this technique may be a useful tool for the individual identification of sea otters as well.     

Brood conspicuousness and clutch viability in male‐caring assassin bugs (Rhinocoris tristis)

Abstract 1. Conspicuousness to mates can bring benefits to both males (increased mating success) and females (reduced search costs), but also brings costs (e.g. increased predation and parasitism). Assassin bugs, Rhinocoris tristis, lay egg clutches either on exposed stems or hidden under leaves. Males guard eggs against parasitoids. Guarding males are attractive to females who add subsequent clutches to the brood. This is an excellent opportunity to study the effects of conspicuousness on the fitness of males and females. 2. Using viable eggs in a multi‐clutch brood as a correlate of fitness, the present study examined whether laying eggs on stems affected (1) female fitness, through exposure to parasitism and cannibalism, and (2) male fitness, through attracting further females. 3. Stem broods were more parasitised. However, males on stems accumulated more mates and more eggs, a net benefit even accounting for parasitism. The eggs gained from being on a stem were cannibalised. By contrast, higher mortality on stems suggests that females should gain by ovipositing on leaves. To the extent that egg viability represents fitness, male and female interests may therefore differ. This suggests a potential for sexual conflict that may affect other species with male care. 4. Despite higher costs, females actually initiated more broods, and subsequently added bigger clutches to broods, on stems than under leaves. This suggests either that viable eggs do not reflect fitness, or that females laid in unfavourable locations. The key is now to address lifetime fitness, since unmeasured factors may affect offspring viability post‐hatching, and to investigate who controls the location of oviposition in R. tristis.     

Revised systematics and biogeography of ‘Quediina’ of sub‐Saharan Africa: new phylogenetic insights into the rove beetle tribe Staphylinini (Coleoptera: Staphylinidae)

Abstract Quediina, a mega‐diverse conventional subtribe of the rove beetle tribe Staphylinini, is remarkably species rich in the north and south temperate regions of the world. Tropical faunas of this group, and the fauna of the entire Afrotropical biogeographical region (= Ethiopian region, = sub‐Saharan Africa), in contrast, are remarkably poor. The taxonomic study of the quediine genera of Staphylinini from the Afrotropical region reveals misidentifications for many of them. Their phylogenetic study demonstrates polyphyly of Quediina and reveals a new evolutionary pattern for the entire tribe Staphylinini. In particular, the formerly quediine genera Euristus Fauvel, 1899 , Ioma Blackwelder, 1952, Natalignathus Solodovnikov, 2005 , all endemic in the Afrotropical region, belong to the non‐related ‘Staphylinina’, ‘Philonthina propria’ and ‘Tanygnathinina sensu novo’ lineages of Staphylinini, respectively. Contrary to earlier records, the genus Quedius Stephens, 1929 does not occur in Africa south of Sahara: Quedius angularis Cameron, 1948 and Quedius cinctipennis Cameron, 1951 are moved to the genus Philonthus Stephens, 1829. The same is established for the Asian genus Algon Sharp, 1874, formerly for a long time associated with Quediina: African species Algon robustus Wendeler, 1928 is moved to the genus Moeocerus Fauvel, 1899 (here in the ‘Philonthina propria’ lineage); and the misidentification of Algon africanus Bernhauer, 1915, a species that probably belongs to a new genus, is discussed. The phylogenetic affiliation of Afroquedius Solodovnikov, 2006 , a South African endemic, is still ambiguous. Overall, the formerly seen bipolar distribution pattern for the ‘Quediina’ is demonstrated to be an artefact, not a reality to explain. Historical biogeographical explanations are proposed for some of the Afrotropical endemics, partly as an attempt to apply biogeography as an external criterion for the evaluation of the new phylogenetic pattern revealed for Staphylinini. The monotypic genera Euristus and Ioma, as well as Heterothops megalops Cameron, 1959 , the only representative of this widespread genus in the Afrotropical region, are redescribed. Limits and synapomorphies of the genus Heterothops are discussed. The following new combinations and new names are proposed: Philonthus cinctipennis ( Cameron, 1951 ) comb.n. (preoccupied by Philonthus cinctipennis Fauvel, 1875), here replaced by Philonthus pseudoquedius Solodovnikov nom.n. ; Philonthus angularis ( Cameron, 1948 ) comb.n. ; Moeocerus robustus ( Wendeler, 1928 ) comb.n. [preoccupied by Moeocerus robustus (Gestro, 1881)], here replaced by Moeocerus wendeleri Solodovnikov nom.n. A lectotype is designated for Heterothops megalops Cameron, 1959 .     

Phylogeography of palo santo trees (Bursera graveolens and Bursera malacophylla; Burseraceae) in the Galápagos archipelago

Two species of palo santo trees are distributed in the Galápagos archipelago, the native Bursera graveolens and the endemic Bursera malacophylla (Burseraceae). However, a zone of individuals morphologically intermediate between the two exists on northern Santa Cruz Island and south‐eastern Santiago Island, suggesting that they may not be reproductively isolated. Here we review the species' distributional and morphological differences and test for evidence of hybridization between the two species using DNA sequence and AFLP data. We find that the species lack distinguishing synapomorphies across the five nuclear and plastid regions examined. Population assignment tests and population genetic analyses of AFLP data indicate that genetically similar palo santo individuals (N = 87), including putative hybrids, partition into two genealogical groups that do not uniformly correspond to island‐ or taxon‐based membership. Furthermore, genotypic admixture levels among morphologically intermediate individuals do not indicate widespread hybridization. Thus, we recommend recognizing the endemic palo santo taxon as B. graveolens subspecies malacophylla (B.L.Rob.) A. Weeks & Tye comb. & stat. nov. in light of its close genetic relationship to B. graveolens subsp. graveolens and its distinctive morphology and distribution. Future research should quantify phenotypic variation in palo santo populations as another means for understanding the basis of morphological differences between the subspecies. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 396–410.     

Wood composition and energy content in a poplar short rotation plantation on fertilized agricultural land in a future CO2 atmosphere

To study the influence of elevated CO₂ and nitrogen (N) fertilization on wood properties and energy, Populus × euramericana trees were exposed to ambient CO₂ (about 370 μmol mol⁻¹ CO₂) or elevated CO₂ (about 550 μmol mol⁻¹ CO₂) using Free Air CO₂ Enrichment (FACE) technology in combination with two N levels. Elevated CO₂ was maintained for 5 years. After three growing seasons, the plantation was coppiced, one half of each experimental plot was fertilized and secondary sprouts were harvested after two growing seasons. Fourier transform infrared (FT-IR) spectra of wood revealed significant effects of both elevated CO₂ and N fertilization on wood chemistry, in particular, significant increases in lignin and decreases in N content. These results were corroborated by chemical analysis. Neither elevated CO₂ nor N fertilization affected the calorific value of wood, which was 19.3 MJ kg⁻¹. N fertilization enhanced the energy production per land area by 16–69% because of higher aboveground woody biomass production than on nonfertilized land. Estimates indicate that high yielding poplar short rotation cultivation may significantly contribute as an alternative feedstock for energy production.     

Relationship between fire,climate oscillations,and drought in British Columbia,Canada, 1920–2000

Climate oscillations such as El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) are known to affect temperature and precipitation regimes and fire in different regions of the world. Understanding the relationships between climate oscillations, drought, and area burned in the past is required for anticipating potential impacts of regional climate change and for effective wildfire‐hazard management. These relationships have been investigated for British Columbia (BC), Canada, either as part of national studies with coarse spatial resolution or for single ecosystems. Because of BC's complex terrain and strong climatic gradients, an investigation with higher spatial resolution may allow for a spatially complete but differentiated picture. In this study, we analyzed the annual proportion burned–climate oscillation–drought relationships for the province's 16 Biogeoclimatic Ecosystem Classification (BEC) zones. Analyses are based on a digital, spatially explicit fire database, climate oscillation indices, and monthly precipitation and temperature data with a spatial resolution of 400 m for the period 1920–2000. Results show that (1) fire variability is better related to summer drought than to climate oscillations, and that (2) fire variability is most strongly related to both, climate oscillations and summer drought in southeastern BC. The relationship of area burned and summer drought is strong for lower elevations in western BC as well. The influence of climate oscillations on drought is strongest and most extensive in winter and spring, with higher indices being related to drier conditions. Winter and spring PDO and additive winter and spring PDO+ENSO indices show BC's most extensive significant relationship to fire variability. Western BC is too wet to show a moisture deficit in summer that would increase annual area burned due to teleconnections.     

Nitrogen deposition,vegetation burning and climate warming act independently on microbial community structure and enzyme activity associated with decomposing litter in low‐alpine heath

Low‐alpine heathlands are thought to be particularly sensitive to nitrogen (N) deposition, climate and land management change, yet little is known about how these factors regulate key belowground processes, like litter turnover, under field conditions. Here we use an in situ factorial field experiment to test the effects of increased atmospheric N deposition, climate manipulation and past vegetation burning, and their interactions, on litter decomposition and the activity and diversity of associated microorganisms. The use of litter from within (native) and outwith (standard) the experimental plots also enabled us to test whether decomposition and microbial functional diversity is driven primarily by soil conditions or litter chemistry. In general, extracellular enzyme activities of litter were driven by additions of simulated N deposition with phosphatase being the most responsive. We found that standard litter incubated in plots that had been burnt 8 years previously decomposed slower and lost less N and phosphorus than in unburnt plots. This material also had associated with it the greatest activity of glucosidase and the least diverse microbial community, as assessed by culture‐independent methods. Although all treatments significantly affected microbial diversity, burning explained most of the variability, indicating a close coupling between plant and microbial communities in these treatments. A striking feature of all the data relating to both standard and native litter was an almost complete lack of interactive effects between the treatments. The lack of interactions between the treatments indicates that each perturbation might affect different mechanisms in the decomposition process (including the composition of associated microbial communities) and nutrient cycling.     

Riparian land use and the relationship between the benthos and litter decomposition in tropical montane streams

1. Although stream–catchment interactions have been analysed in some detail in temperate environments, little is known about the effects of land‐use changes in the tropics. Here, we analyse differences in benthic communities (macroinvertebrates and fungi) under two contrasting land uses (mature secondary forest and pasture) in montane streams in north‐western Ecuador and their influence on the rates of litter processing. 2. Between 2005 and 2006, we used a combination of coarse and fine mesh bags to study the relative contribution of macroinvertebrates and fungi to processing of two types of litter, Alnus acuminata and Inga spectabilis, in three‐first‐order streams running through mature secondary montane forests and adjacent downstream reaches running through pastures. At the same time, we characterised the assemblages of shreddering macroinvertebrates and fungi communities and the litter processing rates in stream reaches under both vegetation types. 3. Litter processing rates attributable to invertebrate feeding (coarse mesh bags) were significantly slower in streams running through pastures. Nevertheless, shredder diversity and richness were similar between pasture and forest sections, while shredder abundance was significantly higher in forest streams (mainly Phylloicus sp. :Trichoptera). Fungal reproductive activity and litter processing rates were low (fine mesh bags) and did not differ significantly between pasture and forest stream reaches. 4. Phylloicus sp. abundance was the best predictor of the percentage of litter remaining in coarse mesh bags across pasture and forest sites. Neither shredder diversity nor their species richness was a significant predictor of mass loss, as most of the decomposition was performed by a single keystone species. Although litter decomposition by microbial decomposers was low, fungal biomass (but not diversity) was the best variable explaining the percentage of litter remaining in fine mesh bags. 5. Our data suggest that, in these Neotropical montane streams, land use can have a significant impact on the rates of critical ecosystem processes, such as litter decomposition. In this study, this effect was not mediated by a major shift in the structure of the benthos, but by a decrease in the abundance and relative representation of a single species whose life history makes it critical to litter processing. 6. This study highlights the significant role that macroinvertebrate fauna can have in the processing of litter in Neotropical streams and the predominant role that single species can have in terms of controlling stream ecosystem‐level processes. Understanding the extent to which these patterns affect the long‐term and large‐scale functioning of stream ecosystems still needs further research and will become increasingly important in terms of managing lotic ecosystems in the context of rapid land‐use change.