Variation in age of primiparity in mountain goats estimated from horn growth increments

Variation in age of primiparity is important for population dynamics and wildlife management because it can affect population growth. Using a novel technique based on the trade-off between annual horn growth and reproduction, we estimated the age of primiparity for 2274 female mountain goats (Oreamnos americanus, de Blainville 1816) harvested across British Columbia, Canada, from 1976 to 2019. We then investigated spatio-temporal variation in the probability that harvested females were primiparous when aged three, four or five years and older using Bayesian ordinal regressions. We found that the probability of primiparity at three years decreased over time in nearly all mountain ranges. In the Coastal Mountain range, however, the probability of primiparity at age three significantly increased. These results suggest that the large coastal populations of mountain goats could be more resilient to harvest than other populations in British Columbia, which may be experiencing environmental effects promoting later primiparity. Models predicting age of primiparity from annual growth measures are a valuable tool for wildlife management and could help conservation of many species.

The Central Valley Salmonid Story: Six Million Years in the Making

For over six million years, salmon and steelhead (known as salmonids) have returned to the California Central Valley. After swimming under the Golden Gate Bridge and through the San Francisco Bay, adult salmonids swim hundreds of miles up the Sacramento or San Joaquin Rivers. Before dams were built, three out of the five salmonid species swam from the Central Valley into high-elevation, cold-water streams within the Sierra Nevada, southern Cascades, and Coastal Mountain ranges to finish their life cycles. Unfortunately, barriers such as dams cut-off salmonids from their home streams. When salmonid populations decrease, the effects are felt across the ecosystem—everything from microbes to humans feels the disconnection between the rivers and the ocean. Governmental agencies and their partners are teaming up to restore Central Valley salmonid populations by reconnecting them to their habitats and putting them back into high-elevation streams.

Calceolaria flavida (Calceolariaceae) a new endemic species to central Chile

A new species of Calceolaria endemic to central Chile is described. A comparison with morphologically similar species is made, and a key as well as detailed images to differentiate them is provided. The species is only known from the Natural Sanctuary Cerro El Roble, which is part of the coastal mountain range of central Chile and can be considered as  Critically Endangered (CR) under the IUCN categories and criteria.

Spatial dynamics of soil erosion impacts on food, water and energy security in a large Andean river basin, Chile

<p>The Rapel Basin (ca 14,000 km<sup>2</sup>), Chile, provides a wide range of ecosystem services from mining activities and water supply from its Central Andean headwaters to mixed agricultural food production and hydropower generation in the Central Valley. The breadth of ecosystem service provision, range of land use and wider anthropogenic pressures makes the Rapel system an ideal natural laboratory in which to evaluate tools to support soil erosion mitigation in the context of enhancing food, water and energy security.</p><p>Taking a distributed approach to encompass geological variability plus superimposed land management and natural process variability, replicate tributary sediment samples (n = 10± per tributary, total number of sediment samples= 313) were collected from across the system to characterise sediment inputs from the major potential sediment sources : (a) natural sediment production in steep Andean headwaters driven by (i) glacial retreat and (ii) seasonal snow melt, (b) sediment inputs from major copper mining operations in the Andes, (d) soil erosion on agricultural land in the Central valley basin area and (e) soil erosion on agricultural land in the Coastal Mountain Belt bordering the hydropower reservoir, Lake Rapel. Samples of river bed sediment from two main sub-catchments (north: Cachapoal River, South: Tinguiririca River) were collected at the outlet to the upper Andean catchment, below the central valley agricultural zone and downstream of a major tributary confluence above the reservoir. In addition, 12 surficial sediment samples were collected from the main arm of the reservoir. All materials were analysed for major and minor element geochemistry by Wave-length Dispersive X-Ray Fluorescence (44 elements).</p><p>Mixtures were compared in terms of their source material groups in a series of nested MixSIAR mixing model runs after selection of appropriate tracer groups following established procedures. In the northern tributary to the reservoir, mining effluent dominated the sediment supply in upper reaches (78%) with the reminder from natural landscape denudation plus a small proportion of glacial-derived sediments (5%). The influence of the mine was diluted by significant inputs of sediment from agricultural sources (fruit orchards and grain production) in the central basin (agriculture 53%, mining 25%) but given the scale of the system, mining remained a major contributor to the reservoir sediment column, with high Cu concentrations (ca 450 mg kg<sup>-1</sup>) observed in reservoir sediment. In the southern tributary, in the absence of mining, natural erosion upstream was dominated by snow melt processes (70%) compared to glacial melt (30%). In the lower reaches downstream of agricultural land, agricultural inputs dominated (53%) with natural erosion in mountain headwaters still contributing (45% overall). Evaluation of reservoir sediment against main geological, natural and anthropogenic tributary-based classification demonstrated significant inputs of sediment from Coastal Mountain agriculture (41%) where steep hillslopes are being actively converted from natural vegetation to plantations (olives, avocados etc). Moreover, sediment contribution coming from mining activities were still considerable (31%).</p><p>Future land-management decisions require quantification of soil erosion  hotspots for targeted mitigation measures. Natural science results are discussed in the context of parallel participatory approaches to developing stakeholder consensus on future actions.</p>

The development process of the Korean coastal mountain range: Examination from spatial distribution of knickzones

Along the eastern margin of the Korean Peninsula, a coastal mountain range spanning over 800 km with summits above 1500 m faces the East Sea (or Sea of Japan), the back-arc sea behind the Japanese Islands. Two contrasting hypotheses exist regarding the tectonic history of this coastal mountain range: long-lasting and progressive uplifts from the Early Tertiary to the Late Quaternary, and a short and intensive uplift during the Early Miocene. However, to date, no consensus has been reached. Here, we studied the spatial distribution of knickzones to understand the formation period and development pattern of this coastal mountain range. We extracted the knickzones in a drainage basin from digital elevation models, and investigated whether or not they are transient knickzones induced by the development of the coastal mountain range. We found that all identified knickzones were stationary, which was verified by slope-area and chi-elevation analyses. This implies that sufficient time has passed for all transient knickzones relevant to the growth of the mountain range to migrate up to the catchment boundary and disappear. We then calculated the time spent for the migration of transient knickzones from the outlet to their stream heads to be at least 5.1 to 10.6 Myr. Therefore, our results suggest that the current form of the coastal mountain range had been built at least before 5.1 Myr ago and has reached a quasi-equilibrium state up to the present, thus invalidating the prevailing hypothesis of the long-lasting and progressive development until the Late Quaternary.

Leucheria cantillanensis (Nassauvieae, Asteraceae), a new species endemic to Central Chile

A new species, Leucheria cantillanensissp. nov., endemic to the coastal mountain range of Central Chile, is described. By using both nDNA and cpDNA, phylogenetic relationships of the new species were investigated. This new species belongs to the acaulescent/subacaulescent clade of Leucheria, which is congruent with the morphology of the species. A detailed description, distribution map, insights about its habitat, conservation status, and illustrations are provided. An updated key for acaulescent/subacaulescent species of Leucheria from Central Chile is also given.