The abundance,distribution and structural characteristics of tree‐holes in Nothofagus forest,New Zealand

Tree‐holes provide an important microhabitat that is used for feeding, roosting and breeding by numerous species around the world. Yet despite their ecological importance for many of New Zealand's endangered species, few studies have investigated the abundance or distribution of tree‐holes in native forests. We used complementary ground and climbed tree surveys to determine the abundance, distribution and characteristics of tree‐holes in undisturbed Nothofagus forest in the Lewis Pass, New Zealand. We found that hole‐bearing trees were surprisingly abundant compared with many other studies, including Australian Eucalyptus species and American beech. In fact, we estimated as many as 3906 tree‐holes per hectare, of which 963 holes per hectare were potentially large enough to provide roost sites for hole‐nesting bats in New Zealand, while only eight holes per hectare were potentially suitable for specialist hole‐nesting birds. This was of great interest as primary cavity‐excavating animals are absent from New Zealand forests, compared with North America and Australia. Moreover, tree‐hole formation in New Zealand is likely to be dominated by abiotic processes, such as branch breakage from windstorms and snow damage. As has been found in many other studies, tree‐holes were not uniformly distributed throughout the forest. Tree‐holes were significantly more abundant on the least abundant tree species, Nothofagus fusca, than on either N. menziesii or N. solandri. In addition to tree species, tree size was also an important factor influencing the structural characteristics of tree‐holes and their abundance in this forest. Moreover, these trends were not fully evident without climbed tree surveys. Our results revealed that ground‐based surveys consistently underestimated the number of tree‐holes present on Nothofagus trees, and illustrate the importance of using climbed inspections where possible in tree‐hole surveys. We compare our results with other studies overseas and discuss how these are linked to the biotic and abiotic processes involved in tree‐hole formation. We consider the potential implications of our findings for New Zealand's hole‐dwelling fauna and how stand dynamics and past and future forest management practices will influence the structural characteristics of tree‐holes and their abundance in remnant forest throughout New Zealand.     

Proteomic and phenotypic profiling of the amphibian pathogen Batrachochytrium dendrobatidis shows that genotype is linked to virulence

Population genetics of the amphibian pathogen Batrachochytrium dendrobatidis ( Bd ) show that isolates are highly related and globally homogenous, data that are consistent with the recent epidemic spread of a previously endemic organism. Highly related isolates are predicted to be functionally similar due to low levels of heritable genetic diversity. To test this hypothesis, we took a global panel of Bd isolates and measured (i) the genetic relatedness among isolates, (ii) proteomic profiles of isolates, (iii) the susceptibility of isolates to the antifungal drug caspofungin, (iv) the variation among isolates in growth and phenotypic characteristics, and (v) the virulence of isolates against the European common toad Bufo bufo . Our results show (i) genotypic differentiation among isolates, (ii) proteomic differentiation among isolates, (iii) no significant differences in susceptibility to caspofungin, (iv) differentiation in growth and phenotypic/morphological characters, and (v) differential virulence in B. bufo . Specifically, our data show that Bd isolates can be profiled by their genotypic and proteomic characteristics, as well as by the size of their sporangia. Bd genotypic and phenotypic distance matrices are significantly correlated, showing that less-related isolates are more biologically unique. Mass spectrometry has identified a set of candidate genes associated with inter-isolate variation. Our data show that, despite its rapid global emergence, Bd isolates are not identical and differ in several important characters that are linked to virulence. We argue that future studies need to clarify the mechanism(s) and rate at which Bd is evolving, and the impact that such variation has on the host–pathogen dynamic.     

Ecosystem feedbacks and cascade processes: understanding their role in the responses of Arctic and alpine ecosystems to environmental change

Global environmental change, related to climate change and the deposition of airborne N‐containing contaminants, has already resulted in shifts in plant community composition among plant functional types in Arctic and temperate alpine regions. In this paper, we review how key ecosystem processes will be altered by these transformations, the complex biological cascades and feedbacks that might result, and some of the potential broader consequences for the earth system. Firstly, we consider how patterns of growth and allocation, and nutrient uptake, will be altered by the shifts in plant dominance. The ways in which these changes may disproportionately affect the consumer communities, and rates of decomposition, are then discussed. We show that the occurrence of a broad spectrum of plant growth forms in these regions (from cryptogams to deciduous and evergreen dwarf shrubs, graminoids and forbs), together with hypothesized low functional redundancy, will mean that shifts in plant dominance result in a complex series of biotic cascades, couplings and feedbacks which are supplemental to the direct responses of ecosystem components to the primary global change drivers. The nature of these complex interactions is highlighted using the example of the climate‐driven increase in shrub cover in low‐Arctic tundra, and the contrasting transformations in plant functional composition in mid‐latitude alpine systems. Finally, the potential effects of the transformations on ecosystem properties and processes that link with the earth system are reviewed. We conclude that the effects of global change on these ecosystems, and potential climate‐change feedbacks, cannot be predicted from simple empirical relationships between processes and driving variables. Rather, the effects of changes in species distributions and dominances on key ecosystem processes and properties must also be considered, based upon best estimates of the trajectories of key transformations, their magnitude and rates of change.     

The effect of ocean acidification and temperature on the fertilization and embryonic development of the Sydney rock oyster Saccostrea glomerata (Gould 1850)

This study investigated the synergistic effects of ocean acidification (caused by elevations in the partial pressure of carbon dioxide pCO₂) and temperature on the fertilization and embryonic development of the economically and ecologically important Sydney rock oyster, Saccostrea glomerata (Gould 1850). As pCO₂ increased, fertilization significantly decreased. The temperature of 26 °C was the optimum temperature for fertilization, as temperature increased and decreased from this optimum, fertilization decreased. There was also an effect of pCO₂ and temperature on embryonic development. Generally as pCO₂ increased, the percentage and size of D‐veligers decreased and the percentage of D‐veligers that were abnormal increased. The optimum temperature was 26 °C and embryonic development decreased at temperatures that were above and below this temperature. Abnormality of D‐veligers was greatest at 1000 ppm and 18 and 30 °C (≥90%) and least at 375 ppm and 26 °C (≤4%). Finally prolonged exposure of elevated pCO₂ and temperature across early developmental stages led to fewer D‐veligers, more abnormality and smaller sizes in elevated CO₂ environments and may lead to lethal effects at suboptimal temperatures. Embryos that were exposed to the pCO₂ and temperature treatments for fertilization and embryonic development had fewer D‐veligers, greater percentage of abnormality and reduced size than embryos that were exposed to the treatments for embryonic development only. Further at the elevated temperature of 30 °C and 750–1000 ppm, there was no embryonic development. The results of this study suggest that predicted changes in ocean acidification and temperature over the next century may have severe implications for the distribution and abundance of S. glomerata as well as possible implications for the reproduction and development of other marine invertebrates.     

Strong links between teleconnections and ecosystem exchange found at a Pacific Northwest old-growth forest from flux tower and MODIS EVI data

Variability in three Pacific teleconnection patterns are examined to see if net carbon exchange at a low‐elevation, old‐growth forest is affected by climatic changes associated with these periodicities. Examined are the Pacific Decadal Oscillation (PDO), Pacific/North American Oscillation (PNA) and El Niño‐Southern Oscillation (ENSO). We use 9 years of eddy covariance CO₂, H₂O and energy fluxes measured at the Wind River AmeriFlux site, Washington, USA and 8 years of tower‐pixel remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to address this question. We compute a new Composite Climate Index (CCI) based on the three Pacific Oscillations to divide the measurement period into positive‐ (2003 and 2005), negative‐ (1999 and 2000) and neutral‐phase climate years (2001, 2002, 2004, 2006 and 2007). The forest transitioned from an annual net carbon sink (NEP=+217 g C m^?2 yr^?1, 1999) to a source (NEP=?100 g C m^?2 yr^?1, 2003) during two dominant teleconnection patterns. Net ecosystem productivity (NEP), water use efficiency (WUE) and light use efficiency (LUE) were significantly different (P<0.01) during positive (NEP=?0.27 g C m^?2 day^?1, WUE=4.1 mg C g^?1 H₂O, LUE=0.94 g C MJ^?1) and negative (NEP=+0.37 g C m^?2 day^?1, WUE=3.4 mg C g^?1 H₂O, LUE=0.83 g C MJ^?1) climate phases. The CCI was linked to variability in the MODIS Enhanced Vegetation Index (EVI) but not to MODIS Fraction of absorbed Photosynthetically Active Radiation (FPAR). EVI was highest during negative climate phases (1999 and 2000) and was positively correlated with NEP and showed potential for using MODIS to estimate teleconnection‐driven anomalies in ecosystem CO₂ exchange in old‐growth forests. This work suggests that any increase in the strength or frequency of ENSO coinciding with in‐phase, low frequency Pacific oscillations (PDO and PNA) will likely increase CO₂ uptake variability in Pacific Northwest conifer forests.     

Private Lands Programs and Lessons Learned in Illinois

ABSTRACT State wildlife agencies commonly offer private landowners cost-share and technical assistance to improve habitat, but the cost-effectiveness and long-term outcomes of these efforts are rarely evaluated. In 1998, we began a 3-part, statewide evaluation of the Illinois Department of Natural Resources’ (IDNR; USA) Private Land Wildlife Habitat Management Program (hereafter the program) as it functioned from 1986 to 1996. We sent a mail-back questionnaire to IDNR biologists to collect information on their perceptions of the program. We sent a separate mail-back questionnaire to private landholders who participated in the program to ascertain their demographic profile, motivations for participation, and attitudes regarding the program. We also conducted on-site evaluations of private properties that were managed under the guidance of the program. We conducted our study to 1) assess if the program effectively assisted participants in establishing and maintaining wildlife habitat, and 2) determine factors associated with optimal management of wildlife habitat on private lands to refine the program and improve effectiveness. We found significant differences between participants in their land use priorities and motivations for managing wildlife and in the resources available to participants to establish and maintain habitat. Our results indicate that although financial incentives may increase participation in private lands initiatives, improving technical and material assistance to landholders is essential for maintaining quality wildlife habitat over the long-term.     

Effectiveness of Vaginal-Implant Transmitters for Locating Elk Parturition Sites

ABSTRACT We assessed success of vaginal implant transmitters (VITs), deployed in 198 elk (Cervus elaphus nelsoni), in locating elk calving sites in western Wyoming, USA, in 2006–2007. We identified 60.3% of expelled VIT locations as definite or probable event markers and an additional 21.8% as possible event markers. Failure rate for VITs was 10.6%, and we found an additional 7.3% in improbable or impossible parturition sites. Vaginal implant transmitters were effective in locating calving and abortion sites and will facilitate definition of parturition habitat selection and parturition ranges of specific subpopulations.     

The so‐called primitive genera of Genisteae (Fabaceae): systematic and phyletic considerations based on karyological data

A karyological analysis of the so‐called primitive genera of Genisteae has shown that they have a relatively homogeneous chromosome complement: all species tend to have a somatic chromosome number 2n = 48, which can increase to 2n = 52, presumably as a result of hyperaneuploidy. Karyological data suggest that Argyrocytisus, Cytisophyllum and Petteria may be considered as distinct genera rather than being assigned to Cytisus, with 2n = 52 for the first of these and 2n = 50 for the other two genera. They may be interpreted as relict monotypic genera as a result of the presence of a stabilized aneuploidy. Karyological characters exclude a recent origin of Genisteae from Thermopsideae. On the contrary, they are consistent with the hypothesis that Genisteae and Thermopsideae are independently derived from a basic papilionoid stock, of which present day Sophoreae are the remainder. At least two lines would lead from Sophoreae to the taxa of the ‘genistoid alliance’, one to Thermopsideae and the other ‘podalyrioid alliances’ (Podalyrieae and Mirbelieae), with the prevailing basic number of x = 9, and the other to Genisteae, with a basic number of x = 12 persisting in some present day genera, including Cytisus s.l. From this lineage, a wide range of secondary basic numbers has been formed, mostly by descending aneuploidy. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 232–248.     

Regional examination shows potential for native feedstock options for cellulosic biofuel production

Kentucky, as with many regions around the globe, has a relatively long growing season with significant rainfall that could produce sizeable quantities of perennial herbaceous and woody biomass on land that does not compete with food crops. Additionally, there are limited options for renewable power production from low carbon sources such as solar-photovoltaic, wind and hydroelectric. Recent studies have shown that producing renewable energy from perennial cellulosic crops, as opposed to starch-based biofuel crops, will have a carbon-mitigating outcome. Currently, there is a lack of data regarding regionally suitable genotypes. Herein, we establish baseline values for multiple entry selections of three native C4 grass species, switchgrass (SW) ( Panicum virgatum L.), eastern gamagrass (EG) (Trispicum dactyloides L. ) and big bluestem (BB) (Andropogon gerardii Vitman ) . Yield potential examined over 7 years showed that environment, species and entries had a significant impact on yield, but EG had higher total yield over the duration of the study. Cellulosic biofuel potential was examined by measurement of saccharification efficiency, relative lignocellulosic energy density, cellulose content and lignin content during three growing seasons. EG had significantly higher digestibility rate than SW and BB. Underlying this was a negative correlation between lignification and saccharification efficiency. However, higher lignin content and higher cellulose content among SW entries resulted in higher energy density relative to EG and BB. These data reveal that locally bred EG varieties were most suited to cellulosic ethanol production under the growing conditions of central Kentucky, USA, compared with SW and BB and suggest the importance of regional examination.