Shrub facilitation increases plant diversity along an arid scrubland-temperate rainforest boundary in South America

Theoretical models predict nurse plant facilitation enhances species richness by ameliorating stressful environmental conditions and expanding distributional ranges of stress-intolerant species into harsh environments. We studied the role of nurse facilitation on the recruitment of perennial plants along an arid scrubland–temperate rain forest boundary to test the following predictions: (1) nurse shrub canopy increases seedling abundance and species richness along the rain forest–scrubland boundary; (2) scrubland species are less dependent on facilitative interactions than temperate rain forest species, especially at the moister, upper end of the gradient

Small-boat surveys for coastal dolphins: line-transect surveys of Hector’s dolphins (Cephalorhynchus hectori)

Management of coastal species of small cetaceans is often impeded by a lack of robust estimates of their abundance. In the Austral summers of 1997−98, 1998−99, and 1999−2000 we conducted line-transect surveys of Hector’s dolphin (Cephalorhynchus hectori) abundance off the north, east, and south coasts of the South Island of New Zealand. Survey methods were modified for the use of a 15-m sailing catamaran, which was equipped with a collapsible sighting platform giving observers an eye-height of 6 m. Eighty-six percent of 2061 km of survey effort was allocated to inshore waters (4 nautical miles [nmi] or 7.4 km from shore), and the remainder to offshore waters (4−10 nmi or 7.4–18.5 km from shore). Transects were placed at 45° to the shore and spaced apart by 1, 2, 4, or 8 nmi according to pre-existing data on dolphin density. Survey effort within strata was uniform. Detection functions for sheltered waters and open coasts were fitted separately for each survey. The effect of attraction of dolphins to the survey vessel and the fraction of dolphins missed on the trackline were assessed with simultaneous boat and helicopter surveys in January 1999. Hector’s dolphin abundance in the coastal zone to 4 nmi offshore was calculated at 1880 individuals (CV=15.7%, log-normal 95% CI=1384−2554). These surveys are the first line-transect surveys for cetaceans in New Zealand’s coastal waters

Archaeology and autonomies: the legal framework of heritage management in a new Bolivia

The 2009 Bolivian Constitution significantly changed the structure of the state and paved the way for the creation of regional, local, and even indigenous autonomies. These autonomies are charged with the management of archaeological sites and museums within their territory. This article answers the question of who currently owns the Bolivian past, it stems from concerns raised at the 2011 renewal hearing of the Memorandum of Understanding preventing the import of illicit Bolivian antiquities into the United States. By combining an analysis of recent legal changes related to the creation of the autonomies and a short discussion of a notable case study of local management of a Bolivian archaeological site, this article offers a basic summary of the legal framework in which Bolivian archaeology and heritage management functions and some preliminary recommendations for governments and professionals wishing to work with Bolivian authorities at the state and local level

The Rain Forests of Home: an Atlas of People and Place

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Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots

22 páginas, 6 tablas, 5 figurasThe Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures.ES received funding from Blancpain, Davidoff Cool Water and The National Geographic Society. Oceana provided funding to ATP. CFG was suported by Grant NC120030 from the Millennium Scientific Initiative.Peer reviewe

Rising to the occasion : a resiliency strategy for Brickell, Miami

As a result of climate change, there has been an increase in flooding all over the world, especially in coastal areas. The coastal city of Miami, Florida is about seventeen feet above sea level at its highest point, with much of the city at five feet or less above sea level. This study is focused in the neighborhood of Brickell. The neighborhood is on the coast and thus acts as a barrier between the Atlantic and other neighborhoods in Miami. The neighborhood has also been the center of a lot of recent growth and development and has become a cultural center. Brickell already experiences flooding when there are large storms, which are becoming more frequent. With a two foot sea level rise, which is projected to happen before the year 2060, about half of the Brickell neighborhood will experience 70 days or more of flooding per year. Despite knowing this, the population of the neighborhood is growing, and it has become the most densely populated neighborhood in Miami. This project proposes a harm reduction strategy for those choosing to live in this, and other areas, where there will be inevitable flooding. This project looks at both vernacular and contemporary precedents of stilted buildings to determine the best structure to support high density buildings in this context. The proposal works with Miami-Dade county’s current resiliency strategies to integrate stilted building into the urban fabric. The buildings function as apartments or office space during dry conditions, but are outfitted for emergency situations as well. This proposal is not a solution to flooding, nor is it a plan for living with water. It is a harm reduction strategy

Migration Routes of New World Sanderlings (Calidris alba)

We color-marked Sanderlings (Calidris alba Pallas) at 19 locations in 6 countries in the New World and coordinated a network of volunteers to locate banded individuals in migration over a five-year period. The observers reported 252 independent sightings of birds in countries different from the country of banding. Sanderlings that migrate north to the Arctic from Chile and Peru travel principally through the central corridor (Texas and northward) of the United States and Canada; smaller numbers follow the Pacific coast. A few migrate north from the Pacific coast of South America along the Atlantic coast of the United States. Southbound from the Arctic to coastal Chile and Peru, many individuals switch eastward to stopovers on the Atlantic coast, including birds that migrated north along the U.S. Pacific coast. Sanderlings banded in Brazil during the nonbreeding period appear only on the U.S. Atlantic coast in migration. Our results emphasize the individual nature of migration. We found considerable heterogeneity in migratory behavior among individuals that spend the nonbreeding season together on the same beaches. Individuals from widely separated nonbreeding sites often shared similar pathways. In this species and perhaps in others, no simple single migratory route connects breeding with nonbreeding regions

Impact of bioturbation on sediment redistribution in coastal Chile - As estimated by combining remote sensing, machine learning and semi-empirical modelling

The burial activity of terrestrial bioturbators influences the microtopography, surface roughness, and physical properties of the soil. By reworking sediments, bioturbators increase soil permeability and porosity, which has implications for infiltration and erosion rates. The construction of underground tunnels distributes and concentrates nutrients and has a particularly positive effect on carbon storage in the soil. Previous studies have left several research gaps. The studies focused only on the habitat preferences of individual species and did not consider the varying amount of excavated sediment and the building density of individual species. It remains unclear which environmental parameters within the catchment area are primarily associated with the high density and distribution of all existing bioturbator structures. Furthermore, the previous authors did not address the daily sediment excavation dynamics by the animal, whether and how it is related to sediment redistribution driven by catchment-wide precipitation, and how much sediment the bioturbators transport to the surface throughout the year. My dissertation was part of the EarthShape consortium with the overarching research question of how microorganisms, animals, and plants influence the shape and development of the Earth's surface. The study was conducted at four study sites along the Chilean coastal cordillera: arid Pan de Azúcar, semi-arid Santa Gracia, Mediterranean La Campana, and humid Nahuelbuta. The workflow consisted of three work packages with the ultimate goal of determining the catchment-wide effects of bioturbation. Within the first work package, I tested whether the density of burrows and the distribution of structures can be predicted by vegetation patterns calculated from UAV and WorldView-2 data. Then I used the best model for catchment-wide prediction. Within the second work package, I tested whether bioturbator-driven sediment redistribution depends on precipitation-driven sediment redistribution. For this purpose, I deployed several time-of-flight-based cameras to monitor sediment redistribution on the trench surface and around the trench. In the third work package, I integrated bioturbation into a soil erosion model. Then I determined the influence of bioturbators on sediment distribution and the environmental parameters that determine the extent of this influence. My results showed that the distribution of structures created by bioturbating animals depends on vegetation patterns. The density of burrows created by bioturbating animals was best predicted by in-situ measured vegetation cover as well as the diameter and height of shrubs. In the arid and semi-arid zones, cactus height and cover were important predictors, while in the humid zone, tree trunk diameter and cover were selected by the model. However, plant species diversity was important in all climatic zones. When predicting burrow density using UAV images, indices of vegetation heterogeneity were also important. The density of structures increased with shrub, herb, and cactus cover in all climatic zones and decreased with tree canopy cover in the humid climate zone. The density of invertebrate structures was higher in rockier areas with less vegetation at all sites. Finally, a vegetation index describing high leaf area index was an important predictor. The distribution of structures throughout the catchment area was best predicted by the WorldView-2 NIR band and NDVI, as well as individual vegetation land cover classes. Topographic features derived from LiDAR data were not selected as important predictors, except for aspect. Secondly, the results showed that sediment redistribution triggered by bioturbators depends on rainfall-triggered redistribution. Immediately after rainfall events in the Mediterranean climate zone, increased sediment export by the animals was observed: the animals were observed reconstructing their structures after the rains and simultaneously excavating more additional sediment to the surface. In contrast, in the arid climate zone, sediment export was mostly not preceded by rainfall events. The results confirmed that the environment determines the extent of the impact of bioturbation on rainfall-induced sediment redistribution throughout the catchment area. The results showed that the key environmental parameters were elevation, surface roughness, slope, and vegetation cover derived from NDVI. Bioturbation increased sediment erosion in areas where erosion processes dominate (steep slopes, strong gradients, low surface roughness, low vegetation cover), and similarly increased sediment accumulation in areas with natural sediment deposition (high surface roughness, high vegetation cover, low slope). The model output demonstrated that bioturbation intensifies sediment erosion. Bioturbation amplified sediment erosion in all climatic zones except the humid zone. Monitoring the structures showed an increase in erosion of over 300% compared to the areas where the structures were embedded. According to the results of the soil erosion model, bioturbation had the strongest impact on erosion in the Mediterranean zone, followed by the arid and semi-arid zones. The effects of bioturbation were not significant in the humid zone. To assess long-term impacts, bioturbation needs to be integrated into landscape development models. However, these models have assumed a uniform distribution and spatial and temporal effects of bioturbation. My results demonstrated that the effects of bioturbation on sediment redistribution are not temporally and spatially consistent, and the distribution of bioturbation is not uniformly associated with vegetation. To realistically predict the long-term effects of bioturbation, the estimated spatial and temporal variations from this study need to be considered

Adaptation of Quinoa (Chenopodium quinoa Willd.) to Australian Environments

Quinoa is being evaluated in cropping systems in many countries outside of its natural range of South America. Very few attempts have been made by farmers or researchers to grow or evaluate quinoa under Australian environments. Given the growing popularity of quinoa with consumers, new commercial opportunities for farmers and international interest in the crop, it was timely to undertake a comprehensive evaluation of the potential of quinoa in Australia. Two advanced selections and nine germplasm lines (six of Chilean and three of Bolivian origin) identified in an earlier project were tested in 23 field trials at 14 locations on mainland Australia. Targets included irrigated sites in tropical, Mediterranean, semi-arid and desert climates, and rain-fed sites of south-western Australia with a Mediterranean climate. The field experiments were either a randomised complete block design (RBCD) or a split plot/factorial design with 2–4 replicates, and a linear mixed model was used to compare the treatment lines. Seed yield of quinoa was highest when grown in winter and spring under rain-fed conditions in Geraldton, in spring and summer under irrigation at Bool Lagoon, and summer, autumn and winter under irrigation at Leeton. The highest seed yield achieved was 3 t/ha for a germplasm line from Chile, while the highest yield for a germplasm line from Bolivia was 2.6 t/ha. Advanced selections from Australia yielded well in comparison at most trial sites. Declining seed yield was associated with mean daily temperatures during seed development increasing above 17 °C, mean daily temperatures during flowering declining below 15 °C, and rainfall during seed development under rain-fed conditions falling below 50 mm. Seed produced at Bool Lagoon was the closest in colour to white quinoa imported from Peru; however, it was more than noticeably different. Seed produced at Geraldton and Leeton was significantly larger than from other field sites; however, none were larger than 2 mm in diameter as found in Royal white quinoa from Bolivia. Superior seed colour and seed size were associated with dry conditions at maturity and cool conditions during seed development, respectively. We conclude that quinoa can become a potential crop option for Australian agriculture by exploiting genetic diversity and supplementing with suitable management practices matched to agro-climatic environments. There are reasonable prospects to raise the seed yield potential in areas in all states, especially in the regions where quinoa grew well in our experiments

Chloroplast genome of Tillandsia marconae till & Vitek (Bromeliaceae), a hyperarid desert endangered species

Tillandsia marconae Till & Vitek (Bromeliaceae) is a rare plant native species that grows over sand, in the coastal desert from Perú and Chile and is considered an endangered species. In this study, we assembled its chloroplast genome. The draft chloroplast genome of T. marconae is ca. 158,873 bp in length, containing a large single-copy region of 86,937 bp, a small single-copy region of 18,506 bp, and a pair of inverted repeat regions of 26,715 bp. The GC content of the draft chloroplast genome is 37.4%. It encodes a total of 135 genes, including 86 protein-coding genes, 38 tRNA genes, 8 rRNA genes, and three pseudogenes. The phylogenetic tree indicated that T. marconae is placed within the Bromeliaceae family and a close relationship with Tillandsia usneoides with 100% support