Schweingruber’s cosmos of inspiration

Born 29^th February 1936 near Bern, Switzerland, Fritz Hans Schweingruber worked as a teacher until 1965, obtained a PhD in botany from the University of Basel in 1972 (where he also obtained a Professorship in 1976), and started his lifelong career at the Swiss Federal Research Institute WSL in Birmensdorf right afterwards. Fritz developed a dendrochronological network across much of the Northern Hemisphere, expanded wood (xylem) science beyond forests, implemented wood anatomical techniques into dendroecology and paleoclimatology, and enthusiastically trained thousands of students, of which hundreds remained actively involved in the still emerging field of tree-ring research. Though Fritz died 7^th January 2020 after an extraordinary academic career, his intellectual legacy will continue to inspire scholars around the world.     

Tree-ring width based streamflow reconstruction for the Kaidu River originating from the central Tianshan Mountains since A.D. 1700

In this study, a 310-year pSeptember–August record of streamflow (where p denotes a month from the previous year) for the Kaidu River was reconstructed based on tree-ring-width from 137 Schrenk spruces (Picea schrenkiana). Spatial correlation showed that this streamflow reconstruction contains local hydroclimatic signals that approximately overlap the Kaidu River watershed. A comparison between the streamflow reconstruction for the Kaidu River and five tree-ring-based hydrological reconstructions for the surrounding areas revealed similar variations in the low-frequency domain. The results of comparison analyses between this reconstruction and other hydrological reconstructions indicated that the hydrological characteristics of the Kaidu River in the 1910s (the driest decade for the Kaidu River in the last 310 years), and the increasing trend of streamflow that began in the 1980s, might have occurred in other areas of the Tianshan Mountains and covered an even larger area. Furthermore, the highest and lowest values of this reconstructed streamflow series capture five flood or snowfall events (1803, 1804, 1836, 1923, and 1959) and six drought events (1894, 1916, 1917, 1918, 1931, and 1944) that were noted in historical documents. The 10.8- and 3.5–5.4-year cycles of this reconstruction coincided with the observed data and other tree-ring based hydrometeorological reconstructions, and revealed the possible influences of solar activity and the atmosphere–ocean system.     

Demographic costs and benefits of herbicide‐based restoration to enhance habitat for an endangered butterfly and a threatened plant

Restoring habitat degraded by invasive species is often a primary focus of conservation strategies, yet few studies investigate the effects of invasive species control on multiple at‐risk taxa. Selective herbicides are increasingly used because they can selectively reduce aggressive invasive plant species with the aim of minimizing effects on other taxa within the habitat. We conducted a four‐year experiment to test how annual application of grass‐specific herbicide affected the demography on Fender's blue butterfly (Icaricia icarioides fenderi) and Kincaid's lupine (Lupinus oreganus), two federally protected species which persist in highly degraded prairie remnants in western Oregon, USA. Effects of herbicide application were transitory for the butterfly; reduction of invasive grasses increased fecundity and led to higher annual population growth (λ) at one of two conservation areas in the first season. There were no detectable differences in λ in subsequent seasons—suggesting that treatments caused neither extensive harm nor extensive benefit to the butterfly population. For the lupine, there were no detectable differences in leaf and flower abundance between control and herbicide treatments. However, greater seed production in herbicide plots in the first and third seasons suggests that lupines in herbicide‐treated plots have greater potential reproductive success. While treatments do not have a long‐term benefit to annual population growth for the butterfly, increasing reproductive success of the threatened plant may justify integrating this strategy into restoration plans. Considering the impact of restoration practices on the demography of multiple at‐risk taxa within a community is critical to effective recovery strategies.     

Moisture changes over the past 467 years in the central Hexi Corridor,northwestern China

The long-term characteristics of precipitation in arid and semi-arid areas are of great interest because these areas are very sensitive to climate change and human activities. The Hexi Corridor is an arid and semi-arid region in northwestern China that also is an important sector of the Silk Road Economic Belt; despite the region’s dependence on precipitation, annually resolved, long-term moisture records are still lacking for this region. Here, a standard tree-ring width chronology spanning 1484–2015 AD is developed for the Hexi Corridor using Qilian juniper (S. przewalskii Kom.). The chronology is used to reconstruct moisture changes in the region over the past 467 years. Correlation analyses indicate that the tree-ring width index has a significant positive correlation with the June SPEI (standardized precipitation evapotranspiration index) on a twelve-month time scale (r=0.73, n=65, p<0.001). We used this information to build a transfer function that explains 52.5% of the variance in the SPEI reconstructed for the period from 1549 CE to 2015 CE. Our study area experienced clear alternations between dry and wet periods. Especially long wet periods include 1600–1650 AD and 1762–1804 AD; long dry periods include 1670–1693 AD, 1917–1970 AD, and 1990–2015 AD. The 1920s was the most severe period of drought in the last 467 years. The results of wavelet analysis and running correlation analysis indicate that the atmospheric circulation system experienced a notable shift around the 1800s, after which point the role of the westerly system grew more pronounced.     

The association between RDW and survival of patients with squamous cell carcinoma of the tongue. Simple,cheap and convenient?

AimThe purpose of this study was to evaluate the prognostic impact of red-cell distribution width (RDW) on the overall survival (OS) of patients with squamous cell carcinoma (SCC) of the tongue.BackgroundDevelopment of cancer is connected with an ongoing inflammatory process which is reflected by laboratory indices, such as RDW that can be used as prognostic tools.Material and methodsThe study group consists of 74 consecutive patients treated with radical radiotherapy or chemo-radiotherapy for SSC of the tongue at one institution between 2005−2014. RDW was assessed based on routine blood tests done before the start of the treatment. ROC curve was applied to assess value of RDW in prediction of OS, and a cut-off value for further tests was obtained using the Younden index. The survival analysis was performed using the Kaplan-Meier method, log-rank testing and Cox regression model.ResultsThe AUC for RDW in ROC analysis was 0.703, and the optimal cut-off value was 13.5%. 5-year OS was significantly lower in patients with RDW ≥ 13.5% compared with patients with RDW < 13.5% (67% vs. 26%, p-value = 0.0005). Additionally, high RDW was associated with a greater odds ratio for 5-year OS in a multivariate Cox proportional hazards regression analysis (3.43, 1.62–7.25; p = 0.001).ConclusionOur study demonstrated that pre-treatment RDW ≥ 13,5% is an indicator of poor overall survival in patients with SCC of the tongue. Since RDW is a cheap and convenient marker, usually routinely assessed during complete blood count tests, it could be further used as an additional prognostic tool in patients with tongue cancers.     

IMP dehydrogenase rod/ring structures in acral melanomas

Acral lentiginous melanoma (ALM) is a rare subtype of melanoma with aggressive behavior. IMPDH enzyme, involved in de novo GTP biosynthesis, has been reported to assemble into large filamentary structures called rods/rings (RR) or cytoophidium (cellular snakes). RR assembly induces a hyperactive state in IMPDH, usually to supply a high demand for GTP nucleotides, such as in highly proliferative cells. We investigate whether aggressive melanoma tumor cells present IMPDH‐based RR structures. Forty‐five ALM paraffin‐embedded tissue samples and 59 melanocytic nevi were probed with anti‐IMPDH2 antibody. Both the rod‐ and ring‐shaped RR could be observed, with higher frequency in ALM. ROC curve analyzing the proportions of RR‐positive cells in ALM versus nevi yielded a 0.88 AUC. Using the cutoff of 5.5% RR‐positive cells, there was a sensitivity of 80% and specificity of 85% for ALM diagnosis. In ALM, 36 (80%) showed RR frequency above the cutoff, being classified as RR‐positive, compared with only 9 (15%) of the nevi (p < .001). Histopathology showed that 71% of the RR‐positive specimens presented Breslow thickness > 4.0mm, compared with only 29% in the RR‐low/negative (p = .039). We propose that screening for RR structures in biopsy specimens may be a valuable tool helping differentiate ALM from nevi and accessing tumor malignancy.     

Mean annual temperature influences local fine root proliferation and arbuscular mycorrhizal colonization in a tropical wet forest

Mean annual temperature (MAT) is an influential climate factor affecting the bioavailability of growth‐limiting nutrients nitrogen (N) and phosphorus (P). In tropical montane wet forests, warmer MAT drives higher N bioavailability, while patterns of P availability are inconsistent across MAT. Two important nutrient acquisition strategies, fine root proliferation into bulk soil and root association with arbuscular mycorrhizal fungi, are dependent on C availability to the plant via primary production. The case study presented here tests whether variation in bulk soil N bioavailability across a tropical montane wet forest elevation gradient (5.2°C MAT range) influences (a) morphology fine root proliferation into soil patches with elevated N, P, and N+P relative to background soil and (b) arbuscular mycorrhizal fungal (AMF) colonization of fine roots in patches. We created a fully factorial fertilized root ingrowth core design (N, P, N+P, unfertilized control) representing soil patches with elevated N and P bioavailability relative to background bulk soil. Our results show that percent AMF colonization of roots increased with MAT (r² = .19, p = .004), but did not respond to fertilization treatments. Fine root length (FRL), a proxy for root foraging, increased with MAT in N+P‐fertilized patches only (p = .02), while other fine root morphological parameters did not respond to the gradient or fertilized patches. We conclude that in N‐rich, fine root elongation into areas with elevated N and P declines while AMF abundance increases with MAT. These results indicate a tradeoff between P acquisition strategies occurring with changing N bioavailability, which may be influenced by higher C availability with warmer MAT.     

带状采伐后不同时期毛竹林恢复和土壤养分特征

为研究带状采伐毛竹林对竹林恢复和土壤养分的影响,以福建省建瓯市毛竹林为研究对象,设置5 m(处理1,C₁)和7 m(处理2,C₂)2种采伐宽度,以不进行采伐处理为对照(CK),研究采伐后当年新鞭生长期(I时期,2018年10月)和采伐后次年新立竹生长期(Ⅱ时期,2019年6月)新竹生长相关指标和土壤养分变化特征。结果表明：(1)C₁、C₂、CK处理的出笋数量分别为2 227、2 650和1 955株·hm^-2,且C₂与C₁、CK差异显著(P<0.05);退笋率各处理之间无显著差异(P>0.05),表现为C₁2。(2)2种采伐处理的胸径(DBH)显著低于CK,表现为CK>C₂>C₁。(3)采伐后Ⅰ时期和Ⅱ时期相比,土壤全磷(TP)和全钾(TK)含量增加,全氮(TN)和全碳(TC)含量降低;采伐后I时期的C₁、C₂处理中土壤TN、TP、TK和TC含量均大于CK,但采伐后Ⅱ时期的土壤TC含量小于CK。研究认为,带状采伐能提高出笋量和立竹数,增加土壤氮磷钾养分含量;7 m带状采伐竹林恢复状况整体上优于5 m带状采伐。     

Agonistic interactions with asymmetric body size in two adult-age groups of the annual killifish Millerichthys robustus (Miller & Hubbs, 1974)

In this study, the author evaluated two adult age groups of the Mexican rivulus Millerichthys robustus with body size asymmetries to determine the strategies used by an annual killifish during agonistic interactions of different ontogenetic stages. To achieve this goal, the author first characterized the ethogram of agonistic interactions of M. robustus composed of seven behavioural units in males and five behavioural units in females. The author then analysed agonistic interaction strategies used by males and females with body size asymmetries in two groups of different adult ages that represent different ontogenetic stages: (a) just after sexual maturity was reached, at 5 weeks of age, and (b) near natural death, at 24 weeks of age. The agonistic behaviour patterns of M. robustus were compatible with the logic of mutual assessment. Large males had an advantage during their interactions in both age groups, winning all of the encounters. Nonetheless, there was more aggression in 5-week-old fish encounters. In addition, small 24-week-old fish were more aggressive than small 5-week-old fish. These changing strategies may be because of the cost–benefits required during a fight at each ontogenetic stage. In the female encounters, size did not predict winners, as both small and large fish won a similar number of encounters, and some contests remained unresolved regardless of age group. There was a tendency for small females of any age to risk more than males in fights to maintain reproductive fitness.     

Annual-Cycle Movements and Phenology of Black Scoters in Eastern North America

Sea ducks exhibit complex movement patterns throughout their annual cycle; most species use distinct molting and staging sites during migration and disjunct breeding and wintering sites. Although research on black scoters (Melanitta americana) has investigated movements and habitat selection during winter, little is known about their annual-cycle movements. We used satellite telemetry to identify individual variation in migratory routes and breeding areas for black scoters wintering along the Atlantic Coast, to assess migratory connectivity among wintering, staging, breeding, and molt sites, and to examine effects of breeding site attendance on movement patterns and phenology. Black scoters occupied wintering areas from Canadian Maritime provinces to the southeastern United States. Males used an average of 2.5 distinct winter areas compared to 1.1 areas for females, and within-winter movements averaged 1,256 km/individual. Individuals used an average of 2.1 staging sites during the 45-day pre-breeding migration period, and almost all were detected in the Gulf of St. Lawrence. Males spent less time at breeding sites and departed them earlier than females. During post-breeding migration, females took approximately 25 fewer days than males to migrate from breeding sites to molt and staging sites, and then wintering areas. Most individuals used molt sites in James and Hudson bays before migrating directly to coastal wintering sites, which took approximately 11 days and covered 1,524 km. Males tended to arrive at wintering areas 10 days earlier than females. Individuals wintering near one another did not breed closer together than expected by chance, suggesting weak spatial structuring of the Atlantic population. Females exhibited greater fidelity (4.5 km) to previously used breeding sites compared to males (60 km). A substantial number of birds bred west of Hudson Bay in the Barrenlands, suggesting this area is used more widely than believed previously. Hudson and James bays provided key habitat for black scoters that winter along the Atlantic Coast, with most individuals residing for >30% of their annual cycle in these bays. Relative to other species of sea duck along the Atlantic Coast, the Atlantic population of black scoter is more dispersed and mobile during winter but is more concentrated during migration. These results could have implications for future survey efforts designed to assess population trends of black scoters. © 2021 The Wildlife Society.