Radial Growth Decline of White Spruce (Picea glauca) During Hot Summers without Drought: Preliminary Results from a Study Site South of a Boreal Forest Border

Here we investigate the possible future response of white spruce (Picea glauca) to a warmer climate by studying trees planted 90 years ago near the southern limit of their climate tolerance in central New York, 300 km south of the boreal forest where this species is prevalent. We employed high-frequency recording dendrometers to determine radial growth phenology of six mature white spruce trees during 2013-2017. Results demonstrate significant reductions in the length of radial growth periods inversely proportional to the number of hot days with air temperature exceeding 30 oC. During years with very hot summers, the start of radial growth began about 3 days earlier than the 2013-2017 average. However, in those same years the end of radial growth was also about 17 days earlier resulting in a shorter (70 versus 100 day), radial growth season. Abundant (350-500 mm) summer precipitation, which resulted in soil moisture values of 20-30% allowed us to dismiss drought as a factor. Instead, a likely cause of reduced radial growth was mean temperature that exceeded daily average of 30^oC that lead to photoinhibition.

Patterns of Genetic Variation in the Eisenia nordenskioldi Complex (Oligochaeta: Lumbricidae) along an Elevation Gradient in Northern China

Eisenia nordenskioldi is the dominant earthworm species in many tundra and boreal habitats. Nothing is known about the genetic diversity of this species along the elevation gradient in China. This study sampled 28 individuals in the E. nordenskioldi complex from Wuling Mountain, northern China, to examine their external morphology and genetic diversity. Mt. Wuling is the southern limit of the distribution of the E. nordenskioldi complex. The specimens from Mt. Wuling were classified into three groups along an elevation gradient. Mismatch distribution analysis suggested that the Pleistocene glaciations possibly did not significantly affect the distribution of earthworm species in this region. We also found that elevation affected the genetic diversity, but not the external morphology of E. nordenskioldi. Given the altitudinal genetic diversity within the E. nordenskioldi complex, the phylogeography of this species provides important information for the zoogeographic reconstruction of the mountains in northern China. With the relatively limited sample size, the result is not conclusive, and further studies need to be conducted in the future to verify the results.

Expansion of Ash Dieback towards the scattered Fraxinus excelsior range of the Italian peninsula

Hymenoscyphus fraxineus, causal agent of Ash Dieback, has posed a threat to Fraxinus excelsior (common ash) in Europe since the 1990s. In south-western Europe, optimal climatic conditions for H. fraxineus become scattered and host density decreases, reducing disease spread rates. To date, the Ash Dieback agent has not been reported from southern and most of central Italy, where native F. excelsior is present as small fragmented populations. This study examines the expansion of Ash Dieback into central Italy, and it considers the consequences of further local spread with regards to the loss of F. excelsior genetic resource. Symptomatic F. excelsior were sampled from sixteen sites in northern and central Italy during 2020. Specimens were analyzed with a culturomics and a quantitative PCR approach. A bibliographic search of F. excelsior floristic reports was conducted for the creation of a detailed range map. The combined use of both techniques confirmed the presence of H. fraxineus in all the sites of central Italy where host plants were symptomatic. These new records represent the southern limit of the current known distribution of this pathogen in Italy, and together with Montenegro, in Europe. The characterization of the F. excelsior scattered range suggests that further spread of Ash Dieback across southern Italy is a realistic scenario. This presents a threat not just to the southern European proveniences of F. excelsior, but to the species as a whole, should Ash Dieback lead to the loss of warm climate adapted genetic material, which may become increasingly valuable under climate change.

Ecophysiological response and morphological adjustment of Argania spinosa L. Skeels under contrasting climates: case study of marginal populations

In this paper, we investigated the seasonal physiological performance and morphological adjustment of Argania spinosa growing under contrasting climatic and biogeographic conditions.Two marginal populations were selected in the main distribution area of the species, one at the Northwest and the other one at the South-west. Trees from the North showed a Mediterranean pattern in Photosynthetic performances, exhibiting maximal carbon assimilation during spring and minimum in summer. In contrast, trees from the South showed a different pattern with maximum values recorded in winter and minimum in spring. Photochemical efficiency of PSII results evidenced the absence of damage to PSII in both sites, probably due to an efficient energy dissipation processed by carotenoid pigments. We recorded increased LMA values in the South, which improves drought resistance. Increasing stomatal length and decreasing stomatal density were registered during the drought season in both populations. A. Spinosa is sensitive to changes in the length of drought stress at its Southern limit. The scarcity of rainfall leading to persistent drought has limited the distribution of the species to the banks of dry Wadis and depressions, where it finds some water compensations during summer. In the North, the summer drought severely impacted the species carbon assimilation.

MODEL FOR MANAGEMENT AND PLANNING OF FISHING PLAYFUL-SPORTS IN THE RIVER MOURO HYDROGRAPHIC BASIN

The Institute for the Conservation of Nature and Forests (ICNF) has recently carried out work on planning and management of recreational fishing in the area of ​​the Mouro River drainage basin — a mountain watercourse in the North of Portugal (River Hydrographic Basin). Minho) which is born near the place of Lagarto (Lamas de Mouro, Melgaço), in the Peneda-Gerês National Park (PNPG). The model adopted was initially implemented (2008) to manage that activity in the Olo river basin (BH of the Douro river), and this methodology also served as a foundation for creating in 2020 in the Northeast region of Trás-os-Montes (Mente rivers, Rabaçal and Tuela – Vinhais and Bragança) plus three recreational fishing areas. In this context, 13 sampling stations were set up (12 in the Mouro river and 1 in the Sucrasto river), considered representative of a large part of the habitats that make up this study area, where actions were carried out to monitor the ichthyofauna (electrical fishing) and hydromorphological characterization of habitats (River Habitat Survey, RHS). The monitoring of benthic macroinvertebrates was an additional action, recently introduced in this type of work, aimed at improving the biological assessment of water quality and aquatic ecosystems and which is serving as a basis for the preparation of a Master's Thesis. With this study, data was analyzed concerning age, growth, physical condition of the monitored specimens, as well as their relationship with the different types of habitats where they were captured. To detect spatial distribution patterns underlying biotic (species/abundance and species/ages) and environmental data, multivariate methods can be used. As a result of this work, the Ludic Fishing Zone (ZPL) of the Mouro River (and its tributaries) will be created, with the aim of promoting recreational and sport fishing based on more conservationist principles. With this initiative, ICNF intends to guarantee greater protection and sustainability of endogenous aquaculture resources, with particular emphasis on the case of Atlantic salmon (Salmo salar). This salmonid annually elects a significant part of these continental waters to complete its reproductive phase. However, other studies, in this context, should be developed to better understand the ecology of the species in a country that coincides with its southern limit of distribution in Europe.

Vulnerability of the Ancient Peat Plateaus in Western Siberia

Based on the data of the plant macrofossil and palynological composition of the peat deposits, the evolution and current state of polygonal peatlands were analyzed at the southern limit of continuous permafrost in the Pur-Taz interfluve. Paleoreconstruction shows that peat accumulation began in the Early Holocene, about 9814 cal. year BP, in the Late Pre-Boreal (PB-2), at a rate of 1 to 1.5 mm year−1. Intensive peat accumulation continued in the Boreal and early Atlantic. The geocryological complex of polygonal peatlands has remained a stable bog system despite the predicted warming and increasing humidity. However, a rather rapid upper permafrost degradation and irreversible changes in the bog systems of polygonal peatlands occur with anthropogenic disturbances, in particular, a change in the natural hydrological regime under construction of linear objects.

Vascular flora of the Outer Banks, North Carolina, U.S.A.

A complete catalogue of the vascular flora of the North Carolina Outer Banks is presented. Rarity, habitat, distribution within the Outer Banks, and earliest and latest specimens are given for each taxon. The flora contains 1020 species and infraspecific taxa, plus an additional 80 taxa that lack voucher specimens. Some 770 taxa are considered native; 250 non-native. Fifty-one taxa reach their northern range limit on the Outer Banks; 11 their southern limit. Fifty-five taxa are listed as rare in North Carolina; one of them also listed Threatened by the U.S. Fish and Wildlife Service. Twenty-four natural communities are described and assessed for vulnerabil-ity to sea level rise. Prior botanical research is listed chronologically.

Genetic insights into the management and conservation of Arctic charr in North Wales

Aquatic species throughout the world are threatened by extinction in many parts of their range, particularly in their most southerly distributions. Arctic charr (Salvelinus alpinus) is a Holarctic species with a distribution that includes the glacial lakes of North Wales, towards it southern limit. To date, no genetic studies have been conducted to determine the genetic health of the three remaining native Arctic charr populations in North Wales, despite exposure to stocking and adverse environmental and ecological conditions. We used seven microsatellite loci to determine whether: 1) genetic differentiation existed between native populations; 2) translocated populations from Llyn Peris were genetically similar to the historically connected Llyn Padarn population; and 3) hatchery supplementation negatively impacted genetic diversity in Llyn Padarn. All three native populations retained their genetic integrity, with Llyn Bodlyn showing high levels of divergence (FST = 0.26 ± 0.02SD) as well as low genetic diversity (HO 0.30) compared to remaining populations (HO 0.64 ± 0.14SD). Although evidence suggests that stocking increased the effective population size of Llyn Padarn in the short term without impacting genetic diversity, the long term effects of such practices are yet to be seen. Results provide baseline data for conservation management, and highlight the need for protection of small isolated populations that are being negatively impacted by the processes of genetic drift due to escalating anthropogenic pressures. Continual monitoring of both Arctic charr and their habitats using a combination of methods will increase the likelihood that these threatened and iconic populations will persist in the future.

First Satellite Telemetry Study of Movement Behavior of Juvenile Golden Eagles from Mexico

ABSTRACT The southern limit of the Golden Eagle's (Aquila chrysaetos) breeding range in North America is Mexico, where the eagle is the national symbol yet designated as a threatened, high priority species for conservation action. Movement information needed for conserving Mexico's Golden Eagles is sparse; knowledge of dispersal from natal areas is essential to understand the eagle's ecology and help provide for its management. Using satellite telemetry data, we analyzed movements of three males and one female from central Mexico during their first year of life; we documented (1) timing and distance of initial dispersal movements, (2) total distance traveled and maximum distance from natal site by month of age following fledging, and (3) size of areas (based on 95% adaptive local convex hulls) across which eagles ranged following initial dispersal. Individual eagles dispersed from their natal areas between mid-September and mid-November, at 6–8 mo of age. Monthly total distance traveled by males reached approximately 350–1350 km at 8–11 mo; the female's peak monthly travel was 3000 km, at age 7 mo. Monthly proximity to natal sites by individuals at ages 8–12 mo was relatively constant, averaging 17.9 km (SD = 5.7) to 129.1 km (SD = 11.3). After dispersal, the monthly ranging areas overall increased during the first year of life for all eagles, especially the female, due mainly to multiple long-distance excursions. Our data suggest that movement behavior of juvenile Golden Eagles from Mexico is mostly similar to that of conspecifics from nonmigratory populations elsewhere. Our study may help serve as a foundation for future work to better understand movement dynamics and resource selection by Mexico's Golden Eagles.

Crust and Upper Mantle Inhomogeneities Beneath Western North Island, New Zealand: Evidence from Seismological and Electromagnetic Data.

<p>Three geophysical techniques have been used to investigate the location and the nature of a large-scale change in crust and uppermost mantle properties below the western North Island of New Zealand. Receiver function analysis reveals a step like change in crustal thickness from ~ 25 km below the northwestern North Island to ≥ 32 km in the southwestern North Island. P-wave attenuation is elevated north of this change in crustal thickness (1000/Qp ≈ 1.9 for α = 0) and is compatible with a wet mantle at near solidus temperatures (T ≈0.97 melting temperature). Attenuation decreases by at least a factor of 2 for the southwestern North Island to values closer to those expected for normal continental lithosphere (1000/Qp ≤ 1 for α = 0). A region of extremely high attenuation (1000/Qp ≈ 5 for α = 0) is observed below the Central Volcanic Region. This value of attenuation is compatible with a wet mantle at temperatures just above melting (T ≈ 1.02 melting temperature). Finally 2D modelling of magnetotelluric data reveals a region of low electrical resistivity (100 Ωm) in the mantle below the region of thinned crust. Like the P-wave attenuation, this region of low resistivity can be explained by a water-saturated mantle at near solidus temperatures (T=0.88-0.97 melting temperature). The changes in crustal thickness, attenuation and electrical resistivity are all coincident with the southern limit of volcanism (~ 39.3°S) at a boundary that runs approximately east-west, perpendicular to the present plate boundary. The only surface expressions of this boundary are the termination of volcanism and the dome-like uplift of the North Island, which has previously been explained by the presence of a buoyant low-density mantle beneath the northwestern North Island. Elevated temperatures and water content inferred from this study are in agreement with this explanation. The sudden transition displayed in all three data sets, but particularly the crustal thickness step seen in the receiver function, calls for a special explanation. Thermal processes are too diffuse to explain the step and instead a mechanical process is called for. One possibility is that the step was created by convective removal of thickened lithosphere.</p>