Search results for "Systematics"

Linnaeus's folly – phylogeny, evolution and classification ofSedum(Crassulaceae) and Crassulaceae subfamily Sempervivoideae

2020

Pretarsal structures in the family Parastrachiidae (Hemiptera: Heteroptera: Pentatomoidea)

2010

Parastrachiidae, for a long time regarded as a subfamily within the Cydnidae (e.g., Schaefer et al. 1988; Schuh and Slater 1995; Gapud 1991), was raised to family level by Sweet and Schaefer (2002), and this position was then accepted by many heteropterists (e.g., Lis and Heyna 2001; Lis and Schaefer 2005; Hironaka et al. 2007; Schaefer and Kikuhara 2007; Lis 2010).

Oceanographic control on shell growth of Arctica islandica (Bivalvia) in surface waters of Northeast Iceland — Implications for paleoclimate reconstr…

2015

Absolutely dated, annually resolved sea surface temperature records from middle to higher latitudes covering long time intervals are crucial to better understand the climate system. Such data can potentially be obtained from variations in shell growth of long-lived bivalves such as Arctica islandica. This study presents the first statistically robust 178-yr long composite chronology (covering 1835–2012) based on sixteen live-collected and subfossil specimens of A. islandica from unpolluted, shallow waters of Northeast Iceland. Between 1875 and 1996, up to 43% of the variation in annual shell growth was explained by SST during February to September. Faster growth occurred when temperatures w…

2020

The fruit of date palm trees are an important part of the diet for a large portion of the Middle East and North Africa. The fruit is consumed both fresh and dry and can be stored dry for extended periods of time. Date fruits vary significantly across hundreds of cultivars identified in the main regions of cultivation. Most dried date fruit are low in sucrose but high in glucose and fructose. However, high sucrose content is a distinctive feature of some date fruit and affects flavor as well as texture and water retention. To identify the genes controlling high sucrose content, we analyzed date fruit metabolomics for association with genotype data from 120 date fruits. We found significant a…

Reassessing the evidence for tree-growth and inferred temperature change during the Common Era in Yamalia, northwest Siberia

2013

AbstractThe development of research into the history of tree growth and inferred summer temperature changes in Yamalia spanning the last 2000 years is reviewed. One focus is the evolving production of tree-ring width (TRW) and tree-ring maximum-latewood density (MXD) larch (Larix sibirica) chronologies, incorporating different applications of Regional Curve Standardisation (RCS). Another focus is the comparison of independent data representing past tree growth in adjacent Yamalia areas: Yamal and Polar Urals, and the examination of the evidence for common growth behaviour at different timescales. The sample data we use are far more numerous and cover a longer time-span at Yamal compared to …

Plant trait‐environment relationships in tundra are consistent across spatial scales

2023

Patterns and processes shaping ecosystems vary across spatiotemporal scales. As plant functional traits reflect ecosystem properties, investigating their relationships with environment provides an important tool to understand and predict ecosystem structure and functioning. This is particularly important in the tundra where a changing climate may trigger severe alterations in plant communities as both summer and winter conditions are changing. Here, we investigate the relationships between key environmental drivers including summer temperature, snow persistence, topographic position and soil pH, and species height, specific leaf area (SLA) and seed mass as plant traits. The study is carried…

Effects of reduced irradiance on hydraulic architecture and water relations of two olive clones with different growth potentials

2009

Abstract The hydraulic architecture and water relations of two olive genotypes, ‘Leccino Dwarf’ (LD) and ‘Leccino Minerva’ (LM) growing at two irradiance levels i.e. full sunlight irradiance (HI) and 50% sunlight irradiance (LI) were studied. The two clones showed similar plant hydraulic conductances (Kplant) and similar conductance of roots and leaves (Kroot and Kleaf) when growing at equal irradiance levels. However, both Kplant and Kroot were significantly lower in LI plants than in HI ones. On the contrary, Kleaf was unaffected by the light regime. One-year-old twigs of LI plants produced longer xylem conduits but lower average diameter of conduits and less conduits per unit xylem cross…

Environmental conditions at the Last Interglacial (Eemian) site Neumark‐Nord 2, Germany inferred from stable isotope analysis of freshwater mollusc o…

2020

Acknowledgements The authors acknowledge the two anonymous reviewers for their useful comments that improved the manuscript. Financial support for the excavations in Neumark‐Nord 2 was provided by the Lausitzer Mitteldeutsche Braunkohlengesellschaft mbH, the Landesamt fur Denkmalpflege und Archaologie Sachsen‐Anhalt (Harald Meller, Susanne Friederich), the Romisch‐Germanisches Zentralmuseum Mainz, the Leids Universiteits Fonds ‘Campagne voor Leiden’ program and the Netherlands Organization for Scientific Research (N.W.O.).

Rare earth elements distribution in seawater and suspended particulate of the Central Mediterranean Sea

2004

Rare earth element (REE) content in suspended and dissolved phases from the Strait of Sicily (Central Mediterranean Sea) has been measured. Vertical profiles of several dissolved REEs along the water column reflect the 3-D oceanographic features of the studied area and identifies the different water masses present there. Shale-normalized REE distribution patterns and derived parameters calculated for the suspended particulate show different atmospheric dust-surface inputs and their interactions with seawater. Finally, combined information from [La/Yb]N, ratios, REE/La ratios and Eu anomalies measured in the suspended particulate suggest an important contribution of volcanic materials from t…

Mittel- und nordeuropäische Weberknechte aus dem Senckenberg Museum Frankfurt (Arachnida: Opiliones)

2005

Central and North European harvestmen from the Senckenberg Museum Frankfurt (Arachnida: Opiliones). About 1100 individuals belonging to 32 opilionid species (300 series), mainly of German origin, were identified based on material provided by, and stored at, the Senckenberg Museum, Frankfurt (Main). A list of all species with habitat information is included. Comments on two remarkable species (Oligolophus hanseni, Odiellus spinosus) are given. The comments include the importance of some series as reference material from MARTENS (1978), additions to regional faunas and the expansion of the known distribution of some thermophilous species.