Two new species and a new record of polydesmoid millipedes from Jiangsu and Zhejiang provinces, eastern China (Diplopoda, Polydesmida)

Liu, Weixin, Huo, Qingbo (2020): Two new species and a new record of polydesmoid millipedes from Jiangsu and Zhejiang provinces, eastern China (Diplopoda, Polydesmida). Zootaxa 4722 (1): 41-49, DOI: 10.11646/zootaxa.4722.1.

Epanerchodus bishou Liu & Huo 2020, new species

<i>Epanerchodus bishou</i>, new species <p>Figs 7–8</p> <p> <b>Type material</b>: Holotype male (SCAU), China, Zhejiang Province, Tianmu Mountain Nature Reserve, 30°19.931’N, 119°26.27’E, 502 m a.s.l., 2018-X-12, Qing-Bo Huo leg. Paratypes: 1 male (SCAU), same locality and data as holotype. 1 male, 1 female (SCAU), same province, Kaihua County, Gutian, 29°14.787′N, 118°7.496′E, 435 m a.s.l., 2018-X-9, Qing-Bo Huo, Peng Gao leg.</p> <p> <b>Etymology</b>: This species epithet, <i>bishou</i> in Chinese meaning “dagger”, is used as a noun in apposition and emphasizes the gonopodal femorite with a prominent, long, dagger-shaped process.</p> <p> <b>Diagnosis</b>: Adult males of <i>E. bishou</i> <b>n. sp.</b> are distinct from other <i>Epanerchodus</i> species by the following combination of characters: (1) broad paraterga (widths of pro- and metazonae 1.6–1.8 and 3.5–3.8 mm, respectively) (Figs 7B, E, H); (2) male tibiae and tarsi with sphaerotrichomes (Fig. 8A); (3) gonopodal femorite with a prominent, long, dagger-shaped process distally and a curved finger-shaped process medially; (4) endomere tip unequally bifid (Fig. 8).</p> <p> The new species seems to be particularly similar to <i>E. sphaerisetosus</i> (from Jinhua in Zhejiang, China), but is distinguished by (1) caudolateral corners of paraterga being square (Fig. 6E) <i>vs.</i> acute-angled in <i>E. sphaerisetosus</i>; (2) exomere absent (Fig. 8) <i>vs.</i> exomere present in <i>E. sphaerisetosus</i>.</p> <p> <b>Description</b>: Based on type specimens. Lengths of both sexes <i>ca.</i> 16–19 mm, widths of pro- and metazonae 1.6–1.8 and 3.5–3.8 mm, respectively.</p> <p> <b>Coloration</b>: generally yellow brownish to dark brownish (Fig. 7).</p> <p> <b>Body</b>: Adults with 20 rings. Width: head <collum <ring 2 <3 <4 <5–15, thereafter (rings 16–19) body gradually tapering towards telson.</p> <p> <b>Head</b>: densely setose, epicranial suture conspicuous (Fig. 7A). Antennae long, reaching past middle of ring 3 when extended posteriorly, slightly clavate (Figs 7 A–C).</p> <p> <b>Exoskeleton</b>: Collum transversely semi-lunar, with three transverse rows of 4+4 setae and a faint lateral incision/denticle on each side. Paraterga broad (Figs 7 A–H), midbody paraterga <i>ca.</i> 2.0–2.2x prozonite width. Paraterga 2–3 slightly upturned dorsally above a faintly convex dorsum, following paraterga flat and subhorizontal (Figs. 7A, D, G). Caudolateral corners of paraterga nearly square, slightly projecting posteriorly past tergal margin, clearly acute only on rings 17–19 (Figs 7 G–H). Integument shining (Fig. 7), prozonae delicately alveolate. Limbus regularly denticulate (Figs 7A, D). Constriction between pro- and metazonae narrow, shallow and smooth (Figs 7B, E, H). Metatergal sculpture faint, with three irregular transverse rows of 3+3 setigerous polygonal bosses. Sulcus between front and middle rows of setae a little deeper than that between middle and caudal rows (Figs 7B, E, H). Tergal setae very short, present on rings 18–19. Three or four faint setigerous incisions at lateral margins of poreless and porebearing rings, respectively. Pore formula normal: 5, 7, 9, 10, 12, 13, 15–19, ozopores evident, dorsal, clearly set off from lateral margin and located between last and penultimate marginal incisions (Figs 7B, E, H). Epiproct short, conical, pre-apical lateral papillae evident. Hypoproct subtrapeziform, with two setigerous papillae (Figs 7 F–H). Pleurosternal carinae present only on ring 2 in both sexes. Sterna sparsely setose, cross-shaped impressions (both axial and transverse) shallow, clearly broadened between male coxae 7 and 9 (Fig. 7C).</p> <p> <b>Legs</b>: long, but stout, about 1.5 (male) or 1.2 (female) times as long as body height, prefemora not bulging laterally; sphaerotrichomes easily visible ventrally on tibiae and tarsi (Fig. 7A).</p> <p> <b>Gonopods</b>: (Figs 7C, I, 8 A–B) Coxa large and squarish, densely setose laterally and with a long seta mesally. Prefemur densely setose and nearly half the length of telopodite. Clivus, or distolateral ridge on femorite, short; femorite with a prominent, long, dagger-shaped process (<b>p1</b>) distally and a curved finger-shaped process (<b>p2</b>) medially, the latter carrying a very small tooth (<b>t</b>) at midway. Endomere (<b>en</b>) curved, unequally bifid, tip of longer branch slightly folded. Seminal groove (<b>sg</b>) starting mesally, distally recurved laterad near base of <b>p2</b>, then turning laterobasad to run into an accessory seminal chamber, the latter opening on a hairy pulvillus. An exomere absent.</p> <p> <b>Remark:</b> Tianmu Mountains is known to be the type locality of four other Diplopoda (Golovatch and Liu, unpublished data).</p>Published as part of <i>Liu, Weixin & Huo, Qingbo, 2020, Two new species and a new record of polydesmoid millipedes from Jiangsu and Zhejiang provinces, eastern China (Diplopoda, Polydesmida), pp. 41-49 in Zootaxa 4722 (1)</i> on pages 46-48, DOI: 10.11646/zootaxa.4722.1.3, <a href="http://zenodo.org/record/3603656">http://zenodo.org/record/3603656</a&gt

Temporal dynamics of fine root production, mortality and turnover deviate across branch orders in a larch stand.

Fine roots play a key role in carbon, nutrient, and water biogeochemical cycles in forest ecosystems. However, inter-annual dynamics of fine root production, mortality, and turnover on the basis of long-term measurement have been less studied. Here, field scanning rhizotrons were employed for tracking fine root by branch order over a 6 years period in a larch plantation. For total fine roots, from the first- to the fifth-order roots, annual root length production, length mortality, standing crops, and turnover rate varied up to 3.4, 2.3, 1.5, and 2.3-folds during the study period, respectively. The inter-annual variability of those roots indices in the first-order and the second-order roots were greater than that of the higher order (third- to fifth-order) roots. The turnover rate was markedly larger for the first-order roots than for the higher order roots, showing the greatest variability up to 20 times. Seasonal dynamics of root length production followed a general concentrated pattern with peak typically occurring in June or July, whereas root length mortality followed a general bimodal mortality pattern with the dominant peak in May and the secondary peak in August or October. Furthermore, the seasonal patterns of root length production and mortality were similar across years, especially for the first-order and the second-order roots. These results from long-term observation were beneficial for reducing uncertainty of characterizing fine root demography in consideration of large variation among years. Our findings highlight it is important for better understanding of fine root dynamics and determining root demography through distinguishing observation years and root branch orders

Rhizosphere Effects along an Altitudinal Gradient of the Changbai Mountain, China

Rhizosphere effects (REs) play important roles in regulating carbon (C) and nutrient cycling in terrestrial ecosystems. However, little is known about the REs of mature trees in the field, especially at the ecosystem scale. This study aimed to explore the variation and patterns of REs in natural ecosystems. Here, combining soil monoliths with an adhering soil (shaking fine roots) method was adopted to sample paired rhizosphere soil and bulk soil along an altitudinal gradient. Based on the relative REs and the percentage of rhizosphere soil mass, the REs on soil C and net nitrogen mineralization rates (Cmin and net Nmin) at the ecosystem scale were estimated. Our results showed that the REs on soil processes, soil microbial biomass C and extracellular enzyme activities (β-glucosidase and N-acetyl-glucosaminidase activities), and soil chemical properties (total C, total N, inorganic N, extractable P, K, Ca, Mg, Fe, and Mn) were significantly positive across altitudinal sites, while soil pH was significantly negative. Although the relative REs on investigated variables varied significantly among altitudes, the relative REs did not show a clear trend with the increased altitudes. Across altitudes, the mean magnitude of ecosystem-level REs on Cmin and net Nmin were 19% (ranging from 4% to 48%) and 16% (ranging from 3% to 34%), respectively. Furthermore, the magnitude of ecosystem-level rhizosphere effects increased linearly with the increased altitudes. The altitudinal patterns of ecosystem-level RE mainly depend on the percentage of rhizosphere soil mass. In conclusion, our results provided a set of new evidence for the REs, and highlighted the need to incorporate REs into land C and N models

Rhizosphere Effects along an Altitudinal Gradient of the Changbai Mountain, China

Rhizosphere effects (REs) play important roles in regulating carbon (C) and nutrient cycling in terrestrial ecosystems. However, little is known about the REs of mature trees in the field, especially at the ecosystem scale. This study aimed to explore the variation and patterns of REs in natural ecosystems. Here, combining soil monoliths with an adhering soil (shaking fine roots) method was adopted to sample paired rhizosphere soil and bulk soil along an altitudinal gradient. Based on the relative REs and the percentage of rhizosphere soil mass, the REs on soil C and net nitrogen mineralization rates (Cmin and net Nmin) at the ecosystem scale were estimated. Our results showed that the REs on soil processes, soil microbial biomass C and extracellular enzyme activities (β-glucosidase and N-acetyl-glucosaminidase activities), and soil chemical properties (total C, total N, inorganic N, extractable P, K, Ca, Mg, Fe, and Mn) were significantly positive across altitudinal sites, while soil pH was significantly negative. Although the relative REs on investigated variables varied significantly among altitudes, the relative REs did not show a clear trend with the increased altitudes. Across altitudes, the mean magnitude of ecosystem-level REs on Cmin and net Nmin were 19% (ranging from 4% to 48%) and 16% (ranging from 3% to 34%), respectively. Furthermore, the magnitude of ecosystem-level rhizosphere effects increased linearly with the increased altitudes. The altitudinal patterns of ecosystem-level RE mainly depend on the percentage of rhizosphere soil mass. In conclusion, our results provided a set of new evidence for the REs, and highlighted the need to incorporate REs into land C and N models

Solutions of food polysaccharide blends for edible films production

The study of the rheological properties of aqueous solutions of starch blends with sodium alginate and agar-agar as well as the physico-mechanical properties of bicomponent films on their basis has been carried out. The extreme behavior of polymer blends with low content of one of the polymers is described in terms of mutual solubility or thermodynamic compatibility. There is a tendency of mechanical properties and water solubility increase with the increasing of SA and AA polymers in corn starch matrix. Obtained data evidence the benefits of bicomponent films production instead of starch-based films

Solutions of food polysaccharide blends for edible films production

The study of the rheological properties of aqueous solutions of starch blends with sodium alginate and agar-agar as well as the physico-mechanical properties of bicomponent films on their basis has been carried out. The extreme behavior of polymer blends with low content of one of the polymers is described in terms of mutual solubility or thermodynamic compatibility. There is a tendency of mechanical properties and water solubility increase with the increasing of SA and AA polymers in corn starch matrix. Obtained data evidence the benefits of bicomponent films production instead of starch-based films