Mammal responses to global changes in human activity vary by trophic group and landscape

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.Peer reviewe

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Decision-support systems for establishing radiata pine plantations in the central North Island of New Zealand

A framework for decision-making relating to establishment of radiata pine plantations was defined, with provision for both numerical models and non-numerical representations of knowledge. Data from Nelder-design experiments were used to investigate the amount of between-tree competition occurring in young radiata pine plantations. Dbhob was found to be unrelated to initial stocking prior to year five. Modelling of basal area/ha growth and yield in a Nelder-design experiment showed that functions used in traditional basal area models under-estimated basal area growth during the two years following the time when mean height was 1.40 m. An adjustment was made to these functions, allowing for allometric assumptions on which growth models are based, which improved models estimates of early basal area/ha growth. Models of young radiata pine survival and size class distribution models were built for crops aged 0 to 5 years in the Central North island region of New Zealand. Data came from site preparation experiments, and the models are sensitive to variations in altitude and site preparation practices. Off-site preparation practices studied, weed control was found to have the largest effect on both initial survival and growth. Mounding improved growth to a lesser extent, and cultivation improved survival of young trees. Fertilisation with nitrogen and phosphorous was found to have a negligible effect on growth and no effect on tree survival. The basal area/ha function incorporated the allometric adjustment developed during the analysis of Nelder-design experiments in a way which resulted in compatible mean height and basal area/ha models. As an illustration of the potential for non-numerical decision-support tools, a knowledge-based computer program was developed to assist forest managers in selecting herbicidal treatments prior to, or during the years following plantation establishment. The system was built using techniques developed for artificial intelligence applications, in a form which allows updating of knowledge relating to weeds, herbicides, surfactants, application methods and treatments, by experts unfamiliar with computer programming. Opportunities for incorporation of these tools into a comprehensive decision-making and control system are discussed

Decline in relative growth rate of 3 juvenile radiata pine clones subjected to varying competition levels in Canterbury, New Zealand

- Relative growth rate (RGR) is the ratio of growth to size at the beginning of the growth period. The assumption that RGR is constant, has been the subject of debate for a long time. In this study, the changes in mean RGR ($\overline{RGR}$) of 3 clones of Pinus radiata D. Don, grown under varying weed competition levels (complete weeding, weeding of 2 m diameter circles, weeding of 1 m diameter circles, and no weeding), were quantified for 3 consecutive years. $\overline{RGR}$ was calculated each winter, using the morphological and physiological characteristics of RGR change which quantified as follows: $$RGR = \underbrace{\frac{dW}{dT}\times \frac{1}{LA}}_{ULR}\times \underbrace{\frac{LA}{LW}}_{SLA}\times \underbrace{\frac{Lw}{W}}_{LWR}$$ where: LA = leaf area, Lw = leaf weight, W = dry weight of the plant, SLA = specific leaf area, i.e. the ratio of area and leaf weight, LWR = leaf weight ratio, i.e. the ratio of total leaf weight of the plant and the total dry weight of the plant, T = time (age), ULR = unit leaf rate. The results showed that the unweeded control treatment had the lowest absolute RGR. $\overline{RGR}$ declined with time and tree size in all the weeded treatments, but increased in the control. The theory that $\overline{RGR}$ is constant (RGR = k model) is shown to be false, as it varies with both time and tree size. Changes in $\overline{RGR}$ during the period studied were best described by an exponential decay function: $\overline{RGR} = a + b \times exp (-cW).$ Clonal differences were also demonstrated: clone 3 showed a lower RGR than the other two clones. This was due to the increased LWR and LAR, leaf area ratio (SLA $\times$ LWR) of this clone. The main reason for mean RGR decline were: (1) reduced ULR with age and size of the plants, (2) changes in allometry and (3) physiological aging which might have accentuated self shading effects. Tree size influenced RGR changes more than age. This study aims to dispel the notion of a constant RGR, and at the same time explains the reasons for the decline o this parameter in young trees.- Baisse du taux de croissance relative de 3 jeunes clones de pin radiata soumis à divers niveaux de compétition, à Canterbury, Nouvelle Zelande. Le taux de croissance relative (RGR) est le rapport entre la croissance et la taille en début de période de croissance. L’hypothèse selon laquelle RGR serait constant a été l’objet depuis longtemps de débats dans divers endroits. Dans cette étude, on a quantifié, pendant 3 années consécutives, les variations de RGR moyen $\overline{RGR}$ de 3 clones de Pinus radiata D. Don soumis à divers niveaux de compétition (désherbage complet, désherbage d’un cercle de 2 m de diamètre, désherbage de 1 m de diamètre, pas de désherbage). $\overline{RGR}$ a été calculé, chaque hiver, à partir de caractéristiques morphologiques et physiologiques de l’évolution du RGR, qui ont été quantifiées comme suit : $$RGR = \underbrace{\frac{dW}{dT}\times \frac{1}{LA}}_{ULR}\times \underbrace{\frac{LA}{LW}}_{SLA}\times \underbrace{\frac{Lw}{W}}_{LWR}$$ LA = surface foliaire totale du plant, Lw = biomasse foliaire totale du plant, W = biomasse totale du plant, SLA = surface foliaire spécifique, c’est-à-dire rapport entre la surface et la biomasse des feuilles, LWR = rapport de biomasse foliaire, c’est-à-dire rapport entre la biomasse foliaire totale du plant et la biomasse totale du plant, T = âge, ULR = efficience folaire unitaire, c’est-à-dire accroissement en biomasse totale du plant rapporté à la surface foliaire. Les résultats obtenus montrent que le RGR est le moins élevé en valeur absolue pour le traitement témoin sans désherbage. $\overline{RGR}$ diminue dans le temps et avec la hauteur des arbres dans tous les traitements avec désherbage alors qu’il augmente pour le témoin. L’hypothèse d’un $\overline{RGR}$ constant (RGR = k modèle) est mise en défaut car il varie dans le temps et avec la hauteur des arbres. L’évolution de $\overline{RGR}$ pendant la période en cause est mieux décrite par une fonction exponentielle décroissante: $\overline{RGR} = a + b \times exp (-cW).$ On a mis en évidence des différences d’évolution de RGR selon les clones, le clone 3 présentant un RGR inférieur à celui des deux autres. Ceci est dû à une valeur supérieure de LWR et de LAR (SLA $\times$ LWR) de ce clone. Les principales raisons de la baisse du RGR moyen sont : (1) décroissance de ULR avec l’âge et la taille des plants, (2) changements allométriques, (3) vieillissement physiologique pouvant accentuer les effets d’auto-ombrage. La taille des arbres joue un rôle plus important que l’âge sur les changements de RGR. Cette étude contribue à supprimer la notion d’un RGR constant tout en fournissant les raisons expliquant la baisse de ce paramètre chez les jeunes arbres

Modelling initial survival and growth of radiata pine in New Zealand.

A sensitive framework has been developed for modelling young radiata pine survival, its growth and its size class distribution, from time of planting to age 5 or 6 years. The data and analysis refer to the Central North Island region of New Zealand. The survival function is derived from a Weibull probability density function, to reflect diminishing mortality with the passage of time in young stands. An anamorphic family of trends was used, as very little between-tree competition can be expected in young stands. An exponential height function was found to fit best the lower portion of its sigmoid form. The most appropriate basal area/ha exponential function included an allometric adjustment which resulted in compatible mean height and basal area/ha models. Each of these equations successfully represented the effects of several establishment practices by making coefficients linear functions of site factors, management activities and their interactions. Height and diameter distribution modelling techniques that ensured compatibility with stand values were employed to represent the effects of management practices on crop variation. Model parameters for this research were estimated using data from site preparation experiments in the region and were tested with some independent data sets

Validation of ultrasonic velocity estimates of wood properties in discs of radiata pine

Abstract Background Measurement of microfibril angle (MFA) in the S2 layer of the cell walls of wood using speed of sound in wood has become a common way to estimate wood stiffness and stability. Measurements across the radius of a disc can be critical, but sonic testing needs to be validated against direct measurements of MFA. Methods A robotic machine that uses two transducers to detect the speed of sound through discs of wood from tree stems was validated by comparing its measurements with wood MFA, air-dry density, and modulus of elasticity assessed by X-ray diffractometry through the “Silviscan” system. Results Ultrasonic velocity (USV) was highly correlated with MFA but not with air-dry density. Variable moving averages were assessed in order to estimate the resolution of the USV measurements, and it appeared that the diameter of the swath detected by the transducers was between 23 and 30 mm. Conclusions It was concluded that MFA in wood samples can be assessed rapidly and cheaply using USV measurements but at lower resolution than assessments using X-ray diffractometry

The millennium shift: Investigating the relationship between environment and growth trends of Norway spruce and Scots pine in northern Europe

For boreal forests in colder climates, changes in environmental conditions are hypothesised to substantially affect ecosystem processes. In this study, trends of top height growth of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst) were analysed using permanent sample plot data from more than 300 long-term experimental sites distributed from temperate zones to the boreal forest conditions in Sweden. By regression analyses, the effects of temperature-sum and precipitation-sum on top height growth were assessed in the period 1986-2018. A significant upward temporal trend in height growth was observed for both species, with the trend more pronounced after the millennium shift. The magnitude of the annual relative height growth after the millennium was about 16.92% and 9.54% higher than expected, respectively for Scots pine and Norway spruce. A potential climate response on height growth was found for both species with temperature-sum positively correlated with top height growth. No significant effect of precipitation-sum on height growth was observed for either species. Our results suggest improved growing conditions and forest sites became more productive in response to increasing temperature in the northern temperate and boreal regions. The increasing growth trends may offer shorter rotation periods and increased forest value for Norway spruce and Scots pine, coupled with contributions of boreal forests to the emerging bio-economy and the regulation of global atmospheric carbon

Linking above-ground biomass production to below-ground carbon fluxes across stocking, clone, fertilization, and understory elimination in Pinus radiata D.Don plantations, New Zealand

The linkage between above-ground biomass production and below-ground carbon fluxes as influenced by silviculture has been insufficiently studied. We tested the effects of stocking, clone, fertilization, and follow-up herbicide treatments on below-ground carbon flux (BCF), above-ground biomass production (AGB), the ratio (BCF/AGB), tree diameter (DBH), height (H), basal area (G), and leaf area index (LAI) for a Pinus radiata D. Don plantation trial in the Canterbury region of New Zealand. Mixed-effects analysis of variance was carried out using data at the plot and clone levels. The H, DBH, G, AGB, BCF and the BCF/AGB ratio were influenced significantly by the main effects of stocking (p < .05), and the follow-up herbicide (p < .001). The main effects of clone had significant influence on H (p < .001), BCF (p < .01) and the BCF/AGB ratio (p < .01). Values of AGB and G increased with stand density, while DBH and H decreased with stand density. The significant stocking x follow-up herbicide interactions observed for DBH, G and AGB, suggested that follow-up weed control alleviated understory-induced water and nutrient stresses. Significant clone x follow-up herbicide interactions for DBH and AGB (p < .05), and clone x stocking interactions for G (p < .05), and no interaction of silvicultural treatments for BCF and BCF/AGB ratio were observed. Clones 1 and 3 exhibited greater AGB and smaller BCF/AGB ratio, compared to slower growing clones (i.e., Clones 4 and 5), suggesting certain clones were more productive above-ground at the expense of less carbon partitioned below-ground. These findings highlight that stocking, follow-up herbicide, and clone, in that order, had the greatest influence on above- and below-ground variables, suggesting that those silvicultural practices shifted carbon partitioning above-and below-ground. We conclude that well-performing clone planted with appropriate stand density and with follow-up weed control treatments may increase aboveground radiata pine productivity.Ministry of Foreign Affair and Trad