Search

Ongoing changes in fire regimes have the potential to drive widespread shifts in Earth's vegetation. Plant traits and vital rates provide insight into vulnerability to fire‐driven vegetation shifts because they can be indicators of the ability of individuals to survive fire (resistance) and populations to persist (resilience) following fire. In 15 study sites spanning climatic gradients in the southern Rocky Mountains, USA, we quantified variation in key traits and vital rates of two co‐occurring, widely distributed conifers (Pinus ponderosa Douglas ex. P. Lawson & C. Lawson and Pseudotsuga menziesii (Mirb.) Franco). We used mixed‐effects models to explain inter‐ and intraspecific variation in tree growth, survival, bark thickness and seed cone production, as a function of species, tree life stage (i.e. diameter, height and age), average climate, local competition and site conditions. Pinus ponderosa was predicted to survive low‐severity fire at a 23% earlier age than P. menziesii. Pinus ponderosa had thicker bark and more rapid juvenile height growth, traits conferring greater fire resistance. In contrast, P. menziesii was predicted to produce seed cones at a 28% earlier age than P. ponderosa. For both species, larger individuals were more likely to survive fire and to produce cones. For P. ponderosa, cone production increased where average actual evapotranspiration (AET) was higher and local competition was lower. More frequent cone production on productive sites with higher AET is an important and underappreciated mechanism that may help to explain greater resilience to fire in these areas. Synthesis. Our analyses indicated that many plant traits and vital rates related to fire differed between Pinus ponderosa and Pseudotsuga menziesii, with trade‐offs between investment in traits that promote individual defence to fire and those that promote recolonization of disturbed sites. Future changes in fire regimes will act as a filter throughout North American forests, with our findings helping to infer which individuals and populations of two iconic species are most vulnerable to future change and offering a framework for future inquiry in other forests facing an uncertain future.

Climate change is causing significant shifts in tree species distributions to higher elevations and latitudes. Seed germination and seedling establishment are particularly important steps in tree range expansion under warmer conditions, yet seedling establishment is influenced by a range of factors beyond temperature, including herbivory, microenvironment, and the timing and amount of precipitation. We conducted an experiment to assess how augmented precipitation regimes, wildlife herbivory, and microclimate influence germination and first-season survival of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) near the upper elevational limit of its range in the southern Rocky Mountains. Germination was strongly influenced by moisture, with over three times higher germination in watered treatments. Seedling survival was similar across watered treatments but was negatively associated with microenvironments with higher maximum temperatures. These results indicate that soil moisture effects on germination and the negative impact of hot growing-season temperatures on seedling survival limit initial seedling establishment in Douglas-fir, even at the cooler and wetter end of its range, suggesting that the planting of this species will be most successful in cooler and wetter microsites. Taken together, this study suggests that continued warming and projected increases in droughts may strongly limit Douglas-fir regeneration and thus its ability to shift upwards with climate change.

Indirect climate effects on tree fecundity that come through variation in size and growth (climate-condition interactions) are not currently part of models used to predict future forests. Trends in species abundances predicted from meta-analyses and species distribution models will be misleading if they depend on the conditions of individuals. Here we find from a synthesis of tree species in North America that climate-condition interactions dominate responses through two pathways, i) effects of growth that depend on climate, and ii) effects of climate that depend on tree size. Because tree fecundity first increases and then declines with size, climate change that stimulates growth promotes a shift of small trees to more fecund sizes, but the opposite can be true for large sizes. Change the depresses growth also affects fecundity. We find a biogeographic divide, with these interactions reducing fecundity in the West and increasing it in the East. Continental-scale responses of these forests are thus driven largely by indirect effects, recommending management for climate change that considers multiple demographic rates., Nature Communications, 12, ISSN:2041-1723

We aimed to disentangle the patterns of synchronous and variable cone production (i.e. masting) and its relationship to climate in two conifer species native to dry forests of western North America. We used cone abscission scars to reconstruct ca 15 years of recent cone production in Pinus edulis and Pinus ponderosa , and used redundancy analysis to relate time series of annual cone production to climate indices describing the North American monsoon and the El Niño Southern Oscillation (ENSO). We show that the sensitivity to climate and resulting synchrony in cone production varies substantially between species. Cone production among populations of P. edulis was much more spatially synchronous and more closely related to large-scale modes of climate variability than among populations of P. ponderosa . Large-scale synchrony in P. edulis cone production was associated with the North American monsoon and we identified a dipole pattern of regional cone production associated with ENSO phase. In P. ponderosa , these climate indices were not strongly associated with cone production, resulting in asynchronous masting patterns among populations. This study helps frame our understanding of mast seeding as a life-history strategy and has implications for our ability to forecast mast years in these species. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

Our overall objective is to synthesize mast-seeding data on North American Pinaceae to detect characteristic features of reproduction (i.e. development cycle length, serotiny, dispersal agents), and test for patterns in temporal variation based on weather variables. We use a large dataset ( n = 286 time series; mean length = 18.9 years) on crop sizes in four conifer genera ( Abies , Picea , Pinus , Tsuga ) collected between 1960 and 2014. Temporal variability in mast seeding (CVp) for 2 year genera ( Abies , Picea , Tsuga ) was higher than for Pinus (3 year), and serotinous species had lower CVp than non-serotinous species; there were no relationships of CVp with elevation or latitude. There was no difference in family-wide CVp across four tree regions of North America. Across all genera, July temperature differences between bud initiation and the prior year (Δ T ) was more strongly associated with reproduction than absolute temperature. Both CVp and Δ T remained steady over time, while absolute temperature increased by 0.09°C per decade. Our use of the Δ T model included a modification for Pinus , which initiates cone primordia 2 years before seedfall, as opposed to 1 year. These findings have implications for how mast-seeding patterns may change with future increases in temperature, and the adaptive benefits of mast seeding. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

International audience; Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current estimates are dominated by overrepresentation of small trees in regression models. We combined global fecundity data, including a substantial representation of large trees. We compared size–fecundity relationships against traditional allometric scaling with diameter and two models based on crown architecture. All allometric models fail to describe the declining rate of increase in fecundity with diameter found for 80% of 597 species in our analysis. The strong evidence of declining fecundity, beyond what can be explained by crown architectural change, is consistent with physiological decline. A downward revision of projected fecundity of large trees can improve the next generation of forest dynamic models.

Prairie streams are dynamic systems in which habitat patches are sporadically created and lost during extreme hydrological events. The persistence of fish species depends on life‐history traits that facilitate their widespread dispersal to recolonize habitats after stochastic extirpation. Artificial barriers are thought to reduce recolonization opportunities and to ultimately displace populations downstream, but the ecological consequences of lost diversity above the barriers are largely unknown. The susceptibility of four prairie fishes to fragmentation and the consequent risk to stream ecosystem processes are described. The selected species exhibit wide tolerances to environmental stressors, represent unique functional feeding guilds, and have different habitat affinities. The ability of each species to access (jumping ability) and successfully traverse (swimming endurance) simulated instream barriers was quantified in the laboratory. Experimental stream complexes were used to isolate the effects of these species on ecosystem structure and function. These replicated single‐species experiments were compared with ‘no fish’ controls to identify the ecological role of each. Small vertical barriers blocked most passage, and with open access all species were unable to traverse relatively short distances against modest water velocities. Stream fragmentation will alter headwater fish assemblage structure and promote the most mobile species. Each species had slightly different effects on the stream ecosystem structure resulting from their different habitat preferences and diets. Without colonization opportunities from neighbouring populations, disturbance events will alter headwater fish assemblages and may degrade the ecosystem structure above barriers. Fragmented riverscapes interact with harsh disturbance regimes to form an ecological ratchet. Systematic species loss above barriers outweighs the opportunity for improvement, suggesting that ecosystem structure may be moving downstream.

Climate change is driving rapid and dramatic changes in forests across the globe, as highlighted by recent widespread drought-induced tree mortality events. Long-term changes in these forest ecosystems will be dependent upon the ability of trees to regenerate following overstory mortality under a warmer and drier climate. The goal of this study was to assess how tree mortality, and environmental gradients imposed by topographic and edaphic conditions, interact to influence tree regeneration in subalpine spruce-fir forests in a region experiencing rapid climate warming. We evaluated regeneration of two widely distributed subalpine forest species of the Rocky Mountains, subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii), across gradients of elevation, aspect, soil type, and overstory subalpine fir mortality. In both species regeneration was strongly associated with local topography and appeared to not be adversely affected by subalpine fir overstory mortality. We found that subalpine fir seedling (height

Drought events occurring under warmer temperatures (i.e. “hotter droughts”) have resulted in widespread tree mortality across the globe, and may result in biome-level vegetation shifts to alternate vegetation types if there is a failure of trees to regenerate. We investigated how overstorey trees, understorey vegetation, and local climatic and edaphic conditions interact to influence tree regeneration, a key prerequisite for resilience, in a region that has experienced severe overstorey tree mortality due to hotter droughts and beetle infestations. We used detailed field observations from 142 sites that spanned a broad range of environmental conditions to evaluate the effects of climate and recent tree mortality on tree regeneration dynamics in the spatially extensive pinon (Pinus edulis)-juniper (Juniperus osteosperma, Juniperus monosperma) woodland vegetation type of the southwestern USA. We used a structural equation modelling framework to identify how tree mortality and local climatic and edaphic conditions affect pinon and juniper regeneration and electivity analyses to quantify the species-specific associations of tree juveniles with overstorey trees and understorey shrubs. Pinon regeneration appears to be strongly dependent upon advanced regeneration, (i.e. the survival of juvenile trees that established prior to the mortality event), the survival of adult seed-bearing trees (inferred from basal area of surviving trees) and the facilitative effects of overstorey trees for providing favourable microsites for seedling establishment. Model results suggest that local edaphoclimatic conditions directly affected pinon and juniper regeneration, such that stands with hotter, drier local climatic conditions and lower soil available water capacity had limited tree regeneration following large-scale dieback. Synthesis. We identify four indicators of resilience to hotter drought conditions: (1) abundant advance regeneration of tree seedlings; (2) sufficient canopy cover for survival of emergent seedlings and existing regeneration; (3) sufficient seed source from surviving trees with high reproductive output; (4) areas with cooler and wetter local climates and greater soil available water capacity. In the absence of these conditions, there is greater likelihood of woodlands transitioning to more xeric vegetation types following dieback.

Forests around the world are undergoing rapid changes due to changing climate and increasing physiological stress, but forest response to climate at the ecosystem scale can be highly variable due to the mixed responses of different trees across heterogeneous landscapes. To determine the response of ecosystems in the Rocky Mountains to climate stress, we investigated the response of subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii), two widely distributed subalpine forest species of Rocky Mountains, to climate warming across a region characterized by gradients of elevation, aspect and soil type. We investigated the growth trend of individual trees through time, determined the climate variables most important for driving growth and quantified the interactions between climate and topography that influence long-term growth trends and potential ecological changes across the study region. Growth trends of these two species are similar through the first part of the century, but diverge during the last several decades. Since 1975, subalpine fir growth decreased through time, while Engelmann spruce growth increased. We find that aspect and warm summer temperatures are the most important factors determining growth in subalpine fir, and subalpine fir growth declines are greatest on east- and south-facing aspects. In contrast, Engelmann spruce growth is uniformly unresponsive to climate. In addition to highlighting the importance of species-level differences in growth response to climate, our results also identify interactions between climate and local physiography as controls on long-term growth trends and suggest that the local landscape physiography can mediate climate-related stress in forested ecosystems. This work advances our understanding of how forest stress is mitigated by landscape factors at the ecosystem scale, and how interactions of species, landscape and climate will control future ecosystem composition and forest growth dynamics.

The cost of plant reproduction or defense at the expense of other fitness traits is a central component of life history theory. Yet the three central resource allocation pathways of growth, reproduction, and defense have rarely been assessed simultaneously nor across individual to landscape scales. This information is critical towards identifying the physiological, environmental, and genetic mechanisms underpinning resource allocation. This study assessed trade-offs in resource allocation between tree growth, defense, and reproduction across scales among piñon pine (Pinusedulis), a widespread mast-seeding conifer of the southwestern USA. Time series (2004-2016) of tree growth (radial and primary shoot growth), defense (resin duct production; a key constitutive defense for this species), and cone production among individual trees from populations across a broad environmental gradient were used to investigate these trade-offs in resource allocation across three scales: individual, population, and landscape. We found evidence for a defense-reproduction trade-off among individuals whereby total resin duct area in annual xylem rings was lower during years of above average cone production. Despite variability in cone and resin duct production across trees within a population and across populations, there was no association between these fitness traits at either of those scales. There was no evidence of trade-offs between cone production and growth at any scales measured, whereas resin duct production and growth were positively related at all scales. Our study suggests that a strategic trade-off occurs whereby investment into defense is temporarily curtailed to favor reproduction, despite increased risk of exposure to natural enemies and the ability of piñon pine to simultaneously allocate carbon to growth and defense. Our study provides new insights into physiological expressions of growth, defense, and reproduction over time in this long-lived masting conifer and indicates the presence of trade-offs with direct importance for individual fitness and population dynamics under global change.

Climate warming is contributing to increases in wildfire activity throughout the western United States, leading to potentially long-lasting shifts in vegetation. The response of forest ecosystems to wildfire is thus a crucial indicator of future vegetation trajectories, and these responses are contingent upon factors such as seed availability, interannual climate variability, average climate, and other components of the physical environment. To better understand variation in resilience to wildfire across vulnerable dry forests, we surveyed conifer seedling densities in 15 recent (1988-2010) wildfires and characterized temporal variation in seed cone production and seedling establishment. We then predicted postfire seedling densities at a 30-m resolution within each fire perimeter using downscaled climate data, monthly water balance models, and maps of surviving forest cover. Widespread ponderosa pine (Pinus ponderosa) seed cone production occurred at least twice following each fire surveyed, and pulses of conifer seedling establishment coincided with years of above-average moisture availability. Ponderosa pine and Douglas-fir (Pseudotsuga menziesii) seedling densities were higher on more mesic sites and adjacent to surviving trees, though there were also important interspecific differences, likely attributable to drought and shade tolerance. We estimated that postfire seedling densities in 42% (for ponderosa pine) and 69% (for Douglas-fir) of the total burned area were below the lowest reported historical tree densities in these forests. Spatial models demonstrated that an absence of mature conifers (particularly in the interior of large, high-severity patches) limited seedling densities in many areas, but 30-yr average actual evapotranspiration and climatic water deficit limited densities on marginal sites. A better understanding of the limitations to postfire forest recovery will refine models of vegetation dynamics and will help to improve strategies of adaptation to a warming climate and shifting fire activity.

Forest and woodland ecosystems may be strongly affected by climate change influences on tree population processes such as seed production and seedling recruitment. Yet climate effects on seed production are generally poorly understood, particularly for trees that exhibit masting behavior (i.e. high synchronicity and high inter-annual variability in seed production). This is largely due to the limited amount of long-term datasets on seed production, which are necessary to characterize the highly variable reproductive outputs of masting species. The cone abscission scar method provides a promising approach to accurately determine historical (past 10–20 years) annual cone production, but the method has not been rigorously validated. Here we use a long-term dataset of cone abundance on individually monitored pinyon pine (Pinus edulis) trees to validate the cone abscission scar methodology. Tree cone production estimated using abscission scars was positively associated with observed mature cone and conelet abundances from 8 to 13 years previously (Spearman’s ρ = 0.52 and 0.66, respectively), the time period of our observed historical cone production data. Further, we show that between 4–5 branches per tree and 4–6 trees per site need to be sampled to minimize the variance in cone abundance estimates. Thus, only approximately 3–4 h are needed to obtain an estimate of historical annual cone production in a stand. Overall, we show that the cone abscission scar method provides a robust and time efficient approach to accurately determine historical annual cone production for P. edulis and likely other slow-growing conifer trees.

Recent droughts and increasing temperatures have resulted in extensive tree mortality across the globe. Understanding the environmental controls on tree regeneration following these drought events will allow for better predictions of how these ecosystems may shift under a warmer, drier climate. Within the widely distributed pinon-juniper woodlands of the southwestern USA, a multiyear drought in 2002-2004 resulted in extensive adult pinon mortality and shifted adult woodland composition to a juniper-dominated, more savannah-type ecosystem. Here, we used pre- (1998-2001) and 10-year post- (2014) drought stand structure data of individually mapped trees at 42 sites to assess the effects of this drought on tree regeneration across a gradient of environmental stress. We found declines in pinon juvenile densities since the multiyear drought due to limited new recruitment and high (>50%) juvenile mortality. This is in contrast to juniper juvenile densities, which increased over this time period. Across the landscape, pinon recruitment was positively associated with live adult pinon densities and soil available water capacity, likely due to their respective effects on seed and water availability. Juvenile pinon survival was strongly facilitated by certain types of nurse trees and shrubs. These nurse plants also moderated the effects of environmental stress on pinon survival: Survival of interspace pinon juveniles was positively associated with soil available water capacity, whereas survival of nursed pinon juveniles was negatively associated with perennial grass cover. Thus, nurse plants had a greater facilitative effect on survival at sites with higher soil available water capacity and perennial grass cover. Notably, mean annual climatic water deficit and elevation were not associated with pinon recruitment or survival across the landscape. Our findings reveal a clear shift in successional trajectories toward a more juniper-dominated woodland and highlight the importance of incorporating biotic interactions and soil properties into species distribution modeling approaches.

Large tracts of land across the western United States have been managed over the last century in an effort to increase forage production, reduce the risk of wildland fires, and/or restore ecosystem structure and function. Yet documentation of this land-treatment history is lacking. With the use of data collected from Bureau of Land Management (BLM) field offices across the Colorado Plateau, we quantified the number, spatial extent, and implementation cost of tree-reduction and seeding treatments done in pinon ( Pinus edulis )–juniper ( Juniperus osteosperma, Juniperus monophylla, Juniperus scopulorum ) woodlands between 1950 and 2003. Over 247 000 hectares of land were treated, corresponding to 6.6% of the pinon–juniper vegetation type within BLM-owned lands. Tree-reduction treatments involving chaining, bulldozing, or cabling were most prevalent between the 1950s and 1970s, with over 163 000 ha of land treated with these methods. Prescribed burning became increasingly prevalent in the 1980s, with over 43 000 ha burned. In more recent years, hydroaxe treatments have become common (4 400 ha treated), but to a much lesser extent than prescribed burns. Over 60% of these tree-reduction treatments were done in conjunction with revegetation or seeding treatments. Implementation costs of these tree-reduction treatments were over $26.7 million, with the hydroaxe treatment having nearly three times the cost of implementation than all other tree-reduction treatments. The spatial extent of these tree-reduction treatments and associated implementation costs highlight the importance of research examining the efficacy of these treatments and the potential legacy effects. The land-use history reported in this study and the accompanying freely accessible on-line database is a useful tool to guide research and management objectives and methodology.

Over the last half-century a range of methods have been utilized to reduce trees and shrubs in order to reduce wildfire risk and promote herbaceous vegetation to support livestock and wildlife. We examined the long-term (20–40 year) effects of past tree-reduction treatments on vegetation and ground cover in pinon–juniper woodlands, which is the third most extensive vegetation type in the continental United States. Tree-reduction treatments were conducted between 1963 and 1988 in Grand Staircase-Escalante National Monument, Utah by the US Bureau of Land Management and involved chaining followed by seeding to remove trees and often shrubs. Treatments were effective at increasing perennial grass cover and reducing tree cover over multiple decades. The increase in perennial grass cover was predominantly due to a nonnative species that was seeded, Agropyron cristatum (crested wheatgrass). Surface fuel loads were nearly twice as high in treated areas, likely changing fire behavior and increasing habitat complexity. Treated areas had higher bare mineral soil cover and lower biocrust cover, which may influence soil erosional processes. Interestingly, treated areas had significantly less Pinus edulis (pinon pine) recruitment compared to untreated areas, while there was no change in Juniperus osteosperma (Utah juniper) recruitment. These results indicate that treated areas may become more J. osteosperma dominated in the future due to increased establishment of J. osteosperma compared to P. edulis. Our results show that while treatments were effective at reducing tree cover and increasing herbaceous cover, there were long-term (40 year) treatment effects on vegetation composition and ground cover that need to be taken under consideration when developing future management strategies.

Widespread piñon (Pinus edulis) mortality occurred across the southwestern USA during 2002-2003 in response to drought and bark beetle infestations. Given the recent mortality and changes in regional climate over the past several decades, there is a keen interest in post-mortality regeneration dynamics in piñon-juniper woodlands. Here, we examined piñon and Utah juniper (Juniperus osteosperma) recruitment at 30 sites across southwestern Colorado, USA that spanned a gradient of adult piñon mortality levels (10-100%) to understand current regeneration dynamics. Piñon and juniper recruitment was greater at sites with more tree and shrub cover. Piñon recruitment was more strongly facilitated than juniper recruitment by trees and shrubs. New (post-mortality) piñon recruitment was negatively affected by recent mortality. However, mortality had no effect on piñon advanced regeneration (juveniles established pre-mortality) and did not shift juvenile piñon dominance. Our results highlight the importance of shrubs and juniper trees for the facilitation of piñon establishment and survival. Regardless of adult piñon mortality levels, areas with low tree and shrub cover may become increasingly juniper dominated as a result of the few suitable microsites for piñon establishment and survival. In areas with high piñon mortality and high tree and shrub cover, our results suggest that piñon is regenerating via advanced regeneration.

This study documents 25 y of change in the abundance of Quercus rubra (northern red oak) and Quercus alba (white oak), in a previous chestnut (Castanea castanea)-oak forest in the Southern Appalachians of the eastern U.S.A. Spatially explicit data from 1983–1984 and 2007–2008 of individually mapped trees on two plots in southwestern Virginia were used to examine how the basal area and density of all tree species changed, with specific attention to recruitment, growth, and mortality patterns of Q. rubra and Q. alba. Since the 1980s there has been an increase in the number of shade tolerant trees, primarily Acer pensylvanicum (striped maple), and a decrease in the number of shade intolerant and intermediate shade tolerant trees, including both Q. rubra and Q. alba. We found a negative correlation between A. pensylvanicum abundance and Quercus seedling abundance and a positive correlation between light availability and Quercus seedling abundance. Both Q. rubra and Q. alba have experienced self-thinning, and the previous oak-chestnut forest will likely become increasingly dominated by maples and other shade tolerant species.

With growing interest in the effects of biodiversity on disease, there is a critical need for studies that empirically identify the mechanisms underlying the diversity-disease relationship. Here, we combined wetland surveys of host community structure with mechanistic experiments involving a multi-host parasite to evaluate competing explanations for the dilution effect. Sampling of 320 wetlands in California indicated that snail host communities were strongly nested, with competent hosts for the trematode Ribeiroia ondatrae predominating in low-richness assemblages and unsuitable hosts increasingly present in more diverse communities. Moreover, competent host density was negatively associated with increases in snail species richness. These patterns in host community assembly support a key prerequisite underlying the dilution effect. Results of multigenerational mesocosm experiments designed to mimic field-observed community assemblages allowed us to evaluate the relative importance of host density and diversity in influencing parasite infection success. Increases in snail species richness (from one to four species) had sharply negative effects on the density of infected hosts (;90% reduction). However, this effect was indirect; competition associated with non-host species led to a 95% reduction in host density (susceptible host regulation), owing primarily to a reduction in host reproduction. Among susceptible hosts, there were no differences in infection prevalence as a function of community structure, indicating a lack of support for a direct effect of diversity on infection (encounter reduction). In monospecific conditions, higher initial host densities increased infection among adult hosts; however, compensatory reproduction in the low-density treatments equalized the final number of infected hosts by the next generation, underscoring the relevance of multigenerational studies in understanding the dilution effect. These findings highlight the role of interspecific competition in mediating the relationship between species richness and parasite infection and emphasize the importance of field-informe de xperimental research in understanding mechanisms underlying the diversity-disease relationship.

Sarajevo has two main hospitals, the Kosevo Hospital (a tertiary teaching hospital with 3,000 beds) and the State Hospital (420 beds), which had been a military hospital until the war. Hospital practice had developed as a mixture of local, Russian and European techniques. Emergency medicine as such did not exist. Before the war, at the Kosevo Hospital, emergencies were admitted directly to one of the several specialty clinics that ran independently of others on the same site. Each surgical clinic had its own anaesthetists and ICU. Paediatric surgery, including aspects of children’s plastic surgery, ran in isolation. There was no Emergency Room at the Kosevo Hospital. Although the shortcomings of this system were recognized, it took the pressures of a war to effect a chance. At the start of the war, casualties were taken into “Traumatology” (orthopaedic trauma), where plastic surgery alone was in the same building.

In contemporary Lacanian psychoanalysis, Verhaeghe’s theory of actualpathology / psychopathology in psychosis and the Millerian idea of “ordinary psychosis” provide diverging conceptual approaches to psychosis. In this paper, the two approaches to psychosis are examined with a particular emphasis on “mild psychosis” and compensatory mechanisms. Despite the shared focus on similar clinical phenomena, particularly body disturbances, these two theories provide different explanations of psychosis. Verhaeghe’s theory of psychosis is a synthesis of Lacanian theory, Freud’s idea of actual neurosis and psychoanalytic attachment concepts. Moreover, these ideas are situated in the “schizophrenia / paranoia dichotomy” an important heuristic device utilised in clinical practice with psychosis. In contrast, the Millerian field of ordinary psychosis aims to broaden the idea of psychosis by reviving the idea of “mild psychosis” and the different forms of stabilisation possible in psychosis. Clinicians adapting the idea of ordinary psychosis aim to rethink pivotal Lacanian concepts - “untriggered” psychosis and stabilisation - beyond the scope of the schizophrenia / paranoia dichotomy. Although the idea of ordinary psychosis requires further development, it promise greater utility than Verhaeghe’s model, as it provides a broader and more nuanced approach to the complex vicissitudes of triggering and restitution in psychosis.

The effect of competition on food choice by pigeons was examined in a within-subject laboratory study. Pigeons foraged on maize (the more preferred item) and wheat (the less preferred item) in two conditions: alone and with a competitor. Over the course of the experiment an effect of competition on individual choice developed: the pigeons came to choose less maize before the first grain of wheat was taken, and to show a higher proportion of choices of wheat. The effect of competition was entirely due to resource availability: no effect of the competitor per se was found once the number of grains of maize and wheat available for any one choice was taken into account. Choice behaviour changed over time because the birds learned to forage faster in competition, which in turn led to faster depletion rates.

SUMMARYTwo food source characteristics, floral arrangement and landmark presence, were manipulated so that the influence of each on the flower revisitation frequency by bumble bees (Bombus impatiens) could be assessed. In two experiments, bees were trained to forage for honey-water solution from artificial flowers, which were arranged in one of three configurations: ‘uniform’ (parallel straight lines), ‘irregular’ or ‘irregular with landmarks’. Experiment I used flowers between which the bees had to fly, and Experiment 2 used flowers between which they could walk. In both experiments, bees foraged more efficiently, making proportionately fewer repeat visits, on the uniform layout than they did on the irregular one. The presence of landmarks led to a significantly lower rate of revisitation in Experiment I but not in Experiment 2. The relationship between efficiency and movement patterns is discussed.

The objective of this study was to determine factors that affect cisplatin concentrations in human kidney cortex. We used flameless atomic absorption spectrophotometry to assay platinum in autopsy specimens of kidney cortex obtained from 83 cisplatin-treated patients. Concentrations were correlated with pretreatment factors and treatment conditions using univariate nonparametric statistics. Hierarchical stepwise multiple regression analyses of transformed (to normalize) data were then used to assess which factors were most important, controlling for other factors. Kidney-cortex platinum concentrations varied from 0 to 14.8 micrograms/g (median, 2.04 micrograms/g). The cumulative lifetime dose of cisplatin ranged from 10 to 1120 mg/m2 (median, 112 mg/m2). The time from the last cisplatin dose to death was < 1-609 days (median, 38 days). According to univariate statistics, factors that correlated (P < 0.05) with kidney-cortex platinum concentrations were the cisplatin dose per course, the pretreatment serum urea level, metoclopramide use (positive correlations), the time from the last cisplatin treatment to death, and the pretreatment serum albumin value (negative correlations). Factors that approached significance (0.05 < or = P < or = 0.10) were a history of hypertension, hyperbilirubinemia (positive), the serum calcium level, and phenytoin use (negative). In the multiple regression analysis, after controlling for the cisplatin dose per course and the time from the last treatment to death, only concurrent metoclopramide and phenytoin use entered the model. The hydration volume did not affect corrected kidney-cortex or kidney-medulla platinum concentrations. The following conclusions were reached: (1) it may be feasible to use lower hydration volumes than those used routinely, (2) any effect of hydration volume on cisplatin nephrotoxicity may not be mediated via a reduction in kidney-cortex platinum concentrations, (3) higher cisplatin doses might be tolerated with new 5-hydroxytryptamine-3 (5HT-3) antiemetics than were tolerated with metoclopramide, and (4) phenytoin should be tested for its ability to reduce cisplatin nephrotoxicity.

Objective: To assess factors that affect cisplatin nephrotoxicity. Methods: In 425 patients treated with cisplatin, we assessed the effect of pretreatment factors and treatment conditions on the rise in serum creatinine with the first course of cisplatin, on the maximum rise in serum creatinine over the entire course of the cisplatin therapy, and on residual nephrotoxicity after the last cisplatin treatment ended. (Because of the nature of the relationship between serum creatinine and creatinine clearance, rise in serum creatinine was divided by pretreatment creatinine squared.) Patients were dichotomized into the upper quartile versus the lower three quartiles of degree of nephrotoxicity. Multivariate analyses were based on logistic regression, controlling for cisplatin dose per course. Results: Controlling for cisplatin dose per course, factors most closely associated with nephrotoxicity during the first course of cisplatin were: serum albumin and potassium, body surface area, and administration of cisplatin over 2–5 days per course vs 1 day (negative associations). Controlling for cisplatin dose per course, the single factor most closely associated with maximum life-time cisplatin nephrotoxicity was concurrent use of a vinca alkaloid (negative association). Controlling for cisplatin dose per course, factors most closely associated with residual nephrotoxicity after the end of cisplatin therapy were cumulative dose of cisplatin, concurrent use of metoclopramide (positive associations), uric acid and concurrent use of phenytoin and a vinca alkaloid (negative associations). The association of nephrotoxicity with uric acid and with body surface area was felt to be an artifact resulting from its positive association with pretreatment serum creatinine. Nephrotoxicity during the first course of cisplatin also correlated significantly with autopsy kidney cortex platinum concentrations in 77 evaluable patients. Conclusions: (1) While several factors correlated with cisplatin nephrotoxicity, most of the observed nephrotoxicity was not explained by the variables identified. (2) While most patients received intravenous hydration, patients receiving high hydration volumes did not have significantly less nephrotoxicity than patients receiving lower hydration volumes. (3) Of the variables identified, serum albumin, metoclopramide and phenytoin may have affected nephrotoxicity by altering cisplatin uptake into or distribution within the kidney.

SPARC is a secreted glycoprotein that has been shown to disrupt focal adhesions and to regulate the proliferation of endothelial cells in vitro. Moreover, peptides resulting from the proteolysis of SPARC exhibit angiogenic activity. Here we describe the temporal synthesis, turnover, and angiogenic potential of SPARC in the chicken chorioallantoic membrane. Confocal immunofluorescence microscopy revealed specific expression of SPARC protein in endothelial cells, and significantly higher levels of SPARC were observed in smaller newly formed blood vessels in comparison to larger, developmentally older vessels. SPARC mRNA was detected at the earliest stages of chorioallantoic membrane morphogenesis and reached maximal levels at day 13 of embryonic development. Interestingly, steady-state levels of SPARC mRNA did not correlate directly with protein accumulation; moreover, the protein appeared to undergo limited degradation during days 10-15. Incubation of [125I]-SPARC with chorioallantoic membranes of different developmental ages confirmed that extracellular proteolysis occurred during days 9-15, but not at later stages (e.g., days 17-21). Comparison of peptides produced by incubation with chorioallantoic membranes with those generated by plasmin showed an identical pattern of proteolysis. Plasmin activity was present throughout development, and in situ zymography identified sites of plasminogen activator activity that corresponded to areas exhibiting high levels of SPARC expression. Synthetic peptides from a plasmin-sensitive region of SPARC, between amino acids 113-130, stimulated angiogenesis in the chorioallantoic membrane in a dose-dependent manner; in contrast, intact SPARC was inactive in similar assays. We have shown that SPARC is expressed in endothelial cells of newly formed blood vessels in a manner that is both temporally and spatially restricted. Between days 9 and 15 of chorioallantoic membrane development, the protein undergoes proteolytic cleavage that is mediated, in part, by plasmin. SPARC peptides released specifically by plasmin induce angiogenesis in vivo. We therefore propose that SPARC acts as an intrinsic regulator of angiogenesis in vivo.

Global climate change is expected to produce large shifts in vegetation distribution and has already increased tree mortality, altering forest structure. However, long-term shifts will be partly dependent on the ability of species to reproduce under a novel climate. Few studies have examined the impact of climate change on the reproductive output of long-lived ‘masting' species, or species characterized by episodic reproductive events. Here, we show that seed cone production among pinyon pine (Pinus edulis), a masting species, declined by 40% from the 1974 decade (1969–1978) to the 2008 decade (2003–2012) in revisited stands throughout New Mexico and northwestern Oklahoma. Seed cone production was highly correlated with late summer temperatures at the time of cone initiation. Further, declines in seed cone production were greatest among populations that experienced the greatest increases in growing season temperatures, which were the populations located at the cooler, upper elevations. As growing season t...

After a 4-mo study period, quantitative measures of stable behavioral traits in individual rhesus monkeys correlated significantly with platelet monoamine oxidase (MAO) activity. In particular, behavioral items reflecting social activity and social contact, both agonistic and affiliative, were inversely correlated with enzyme activity. Time spent alone was positively correlated. Since platelet MAO activity is generally stable and predominantly controlled by genetic factors, it might serve as a "genetic marker" for individual differences in "normal" behaviors possibly related to differences in MAO activity in the brain and other tissues.

This study examined the feasibility of maintaining male Hartley guinea pigs on long-term hyperalimentation. Data from animals fed ad libitum, but infused with 0.9% saline, indicated that there was minimal effect from catheter implantation, sepsis, or the infusion of large volumes of fluid. This group compared with animals fed and watered ad libitum demonstrated a nearly identical growth rate (6.33 +/- 1.18 and 6.12 +/- 1.32 g/day, respectively), serum chemistry, tissue weights, and hepatic composition and morphology. Animals infused with a total parenteral diet demonstrated growth rates of 4.06 +/- 1.46 g/day for up to 25 days. Loss of infused animals was due in varying degrees to sepsis, mechanical failure, improper placement of the cannula, loss of patency, and death from unknown causes. Morphological analysis of animals fed by total parenteral nutrition revealed an altered distribution and increased size of lipid droplets in hepatic parenchymal and Kupffer cells and glycogen accumulation by the parenchymal cells. Decreased hepatic content of total protein and lipid, as well as cytochrome P450, was also observed. Similarly, serum values of triglyceride were decreased in animals fed by the total parenteral diet. This study indicated that the guinea pig fed by hyperalimentation may be a useful animal model for a number of clinical and basic research applications.

SUMMARYThe toxicity to the honeybee of apholate, Hexakis (aziridinyl) triazatriphosphorine, was investigated in feeding and contact studies. The LD50 for apholate fed to bees in sugar syrup was 120 μg./g. after 72 hours, whereas for topical drop applications it was 7000 μg./g. after 96 hours. Signs of poisoning are lethargy and inactivity, and appear soon after treatment, but toxic action is slow. Two colonies of bees fed apholate at 0·05% concentration in 3 and 4 litres of syrup were broodless within 23 days. The living worker bees were 20–31% below normal in weight. Apholate in liquid syrup is thus hazardous to bees. Impregnated cord and granular glycerine-sugar baits were, however, not attractive to bees, and caused no harm to them, even with repeated contact.

Psilopa leucostoma (Meigen) was first observed as a pest of sugar beets in the United States at Umapine, Oregon, in 1962. Observations made through 1965 showed it to be generally distributed in the major producing areas of Washington, Oregon, Idaho, and northern Utah. Primary damage to beet plants consists of as many as 50 narrow serpentine mines, usually less than 2 cm long, on a single beet leaf; but the greatest damage is caused later by (death, from an unknown cause, of patches of leaf tissue around the mines. The insect is likely to become a more serious pest of sugar beets and table beets than the spinach leaf miner, Pegomya hyoscyami (Panzer), because it attacks the plants later in the season. It is believed to be a different biotype from the insect that attacks common lambsquarters, Chenopodium album L. It has apparently become adapted to sugar beets grown in irrigated areas on the salt or alkaline soils of the West.

Siphogenerinoides bentonstonei, n. sp., the oldest known representative of this genus, is listed from two localities in the Coniacian of central Colombia. It shows primitive characteristics in its small size, near-absence of a raised lip bordering the aperture, and in the development of a triserial stage in the megalospheric form. A new Siphogenerinoides from the Coniacian of Colombia C. D. REDMOND Arabian American Oil Company Dhahran, Saudi Arabia INTRODUCTION The foraminiferal genus Siphogenerinoides has not previously been reported from beds older than Campanian. Therefore, the presence of a representative of this genus in the Coniacian of Colombia is considered worthy of special note. The occurrences described here were first noted while the writer was in the employ of the International Petroleum Company (Colombia) Limited, in Bogota, Colombia. Common specimens of Siphogenerinoides bentonstonei Redmond, n. sp., were found in samples from International Petroleum Company (Colombia) Limited sample localities no. 62153 and no. C-7778. The stratigraphic position of sample 62153 is shown in textfigure 2, where it may be seen to lie below the range of Siphogenerinoides cretacea Cushman, a Campanian form, and between occurrences of the Coniacian ammonite genus Barroisiceras. Sample C-7778 has not been placed in a measured section, but appears to occupy a position comparable to that of sample 62153. According to a list supplied by Victor Petters (personal communication, March 9, 1953), the following foraminifera occur with S. bentonstonei in sample 62153: Globigerinella sp. Globotruncana fornicata fornicata Plummer Globotruncana ventricosa ventricosa White Gumbelina spp. Robulus minsteri (Roemer). In addition, the assemblage contains new subspecies of Globotruncana fornicata Plummer, Globotruncana lapparenti Brotzen, and Globotruncana tricarinata (Quereau), to be described in a paper by Gandolfi which is now in press (Bulletins of American Paleontology). The author wishes to express his thanks both to the International Petroleum Company (Colombia) Limited, for permission to publish this paper, and to Dr. Victor Petters of the same organization, for his kind contribution of the composite columnar section and additional faunal list. Acknowledgment must also be made to my wife for the preparation of the drawings. TEXT-FIGURE 1 Locality map showing position of Intercol sample 62153 in Quebrada el Salto, near the village of Las Palmas, Department of Magdalena, central Colombia. micropaleontology, vol. 1, no. 3, pp. 247-249, text-figs. 1-5, july, 1955 247 This content downloaded from 157.55.39.231 on Wed, 05 Oct 2016 04:29:32 UTC All use subject to http://about.jstor.org/terms

"Two new genera and eight new species of lituolid foraminifera from the lower Cretaceous and upper Jurassic of Saudi Arabia are described and figured. Two species of Pseudocyclammina occurring here develop Choffatella-like chambers in the microspheric generation. The term 'minimal chamber' is suggested as a designation for such chambers, and the application of the concept to other genera is briefly discussed."