PAICE: A new R package to estimate the number of inter-island colonizations considering haplotype data and sample size

Aim: Colonization is a central topic in ecology and one of the cornerstones of island biogeography. Although the evolutionary history of island species is widely studied, the quantification of colonization is particularly challenging because the same area may be colonized multiple times by the same species, whereas initially successful colonization events may eventually be followed by extinction. Nevertheless, an estimation of the actual number of within-archipelago colonization events can be achieved when using adequate sample size and genetic data, which are essential parameters in the inference of colonization success of any species. Location: Canary Islands, Azores and Galápagos Islands. Taxon: Buteo galapagoensis, Croton scouleri, Setophaga petechia aureola and Xylocopa darwini (Galápagos); Canarina canariensis, Cistus monspeliensis, Juniperus cedrus and Olea europaea subsp. guanchica (Canary Islands); and Juniperus brevifolia and Picconia azorica (Azores). Methods: The new R package PAICE uses haplotype (from organelle DNA) sharing and haplotype relationships, and controls for sampling effort to estimate the number of within-archipelago colonization events in island-like systems. PAICE applies a sampling-effort correction based on rarefaction curves of field sampling (number of individuals or populations) and genetic sampling (number of DNA variable positions). The number of colonization events for the 10 insular species were estimated with PAICE and results compared with previous methods. Results: PAICE estimates a number of inter-island colonization events up to an order of magnitude greater than previous methods. Furthermore, PAICE can quantify the colonization events of any study species, in multiple biogeographic contexts and considering sampling size, thus providing a standardized estimate of colonization success. Main conclusions: The new package PAICE provides an estimation of the number of inter-island colonization events (regardless of dispersal routes or rates) based on haplotype data across islands. This new tool will allow gaining new insights on the intensity of long-distance-dispersal events, their drivers and consequences for the assembly of insular faunas and floras

Scientists' warning on endangered food webs

All organisms are ultimately dependent on a large diversity of consumptive and non-consumptive interactions established with other organisms, forming an intricate web of interdependencies. In 1992, when 1700 concerned scientists issued the first “World Scientists' Warning to Humanity”, our understanding of such interaction networks was still in its infancy. By simultaneously considering the species (nodes) and the links that glue them together into functional communities, the study of modern food webs – or more generally ecological networks – has brought us closer to a predictive community ecology. Scientists have now observed, manipulated, and modelled the assembly and the collapse of food webs under various global change stressors and identified common patterns. Most stressors, such as increasing temperature, biological invasions, biodiversity loss, habitat fragmentation, over-exploitation, have been shown to simplify food webs by concentrating energy flow along fewer pathways, threatening long-term community persistence. More worryingly, it has been shown that communities can abruptly change from highly diverse to simplified stable states with little or no warning. Altogether, evidence shows that apart from the challenge of tackling climate change and hampering the extinction of threatened species, we need urgent action to tackle large-scale biological change and specifically to protect food webs, as we are under the risk of pushing entire ecosystems outside their safe zones. At the same time, we need to gain a better understanding of the global-scale synergies and trade-offs between climate change and biological change. Here we highlight the most pressing challenges for the conservation of natural food webs and recent advances that might help us addressing such challenges.This research has been supported by the Fundação para a Ciência e a Tecnologia (grant nos. UID/BIA/04004/2019 and CEECIND/00092/2017), the National Science Foundation (grant no. 1754221), and the Spanish Ministry of Science, Innovation and Universities (grant no. GCL2017-88122-P)

Export structure analysis of wood industry of Latvia and development possibilities

Maģistra darbā tiek analizētas uzņēmumu konkurētspējas pamatnostādnes zinātniskajā literatūrā, un pētīta ES vienotā kokrūpniecības tirgus situācija, kā arī uzņēmuma SIA „Upeslīči” konkurētspēja un to ietekmējošie faktori. Pirmajā nodaļā tiek pētīts uzņēmumu konkurētspējas jēdziens un apkopotas dažādu ekonomisko skolu konkurētspējas koncepcijas. Otrajā nodaļā tiek analizētas ES kokrūpniecības tirgus piedāvājuma un pieprasījuma veidošanās problēmas. Trešajā nodaļā, pamatojoties uz uzņēmuma SIA „Upeslīči” klientu un darbinieku aptaujas rezultātiem, tiek pētīta uzņēmuma konkurētspēja un to ietekmējošie faktori. Maģistra darbam ir 84 lpp., 29 attēli, 11 tabulas un 4 pielikumi. Atslēgvārdi: konkurētspēja, kokrūpniecība, tirgus, koka iepakojuma nozare, paletesThe essence of firms competitiveness in scientific literature, the situation in the common EU wood industry market, as well as the competitiveness of company SIA „Upeslīči” and the factors influencing it, is analyzed in this paper. In the first chapter the conception of the firms competitiveness and concepts of competitiveness in different economical schools are researched. In the second chapter supply and demand formation problems in the common EU wood industry market are analized. In the third chapter, based on the results of the questionnaire of company’s SIA „Upeslīči” employees and customers, competitiveness of company and the factors influencing it, is researched. This master paper has 84 P., 29 figures, 11 tables and 4 attachments. Keywords: competitiveness, wood industry, market, wood packaging sector, pallet

Status assessment of the Critically Endangered Azores Bullfinch <em>Pyrrhula murina</em>

The Azores Bullfinch is endemic to the island of São Miguel (Azores, Portugal). Its status was uplisted to Critically Endangered in 2005 on the basis of an extremely small and declining population that was considered to be restricted to a very small mountain range (43 km2), in a single location, within which the spread of invasive plants constituted a threat to habitat quality. Nevertheless, information was mostly inferred, or the product of, non-systematic studies. In order to carry out a complete assessment of the conservation status we analysed: (i) population trend, calculated from annual monitoring 1991–2008, (ii) population size, and (iii) range size, obtaining estimates in a single morning study in 2008 involving the simultaneous participation of 48 observers. Contrary to previous inferences, the population is no longer decreasing, although quality of laurel forest habitat continues to decline due to the persistent threat of invasive species. Population size (mean ± SE) was estimated at 1,064 ± 304 individuals using distance sampling methods, although the estimate was very sensitive to the survey method used. Range size estimates (extent of occurrence and area of occupancy) were 144 km2 and 83 km2 respectively. Given the present information, we propose the downlisting of Azores Bullfinch to Endangered on the IUCN Red List

Effects of native biodiversity on grape loss of four castes: testing the biotic resistance hypothesis

<div>The agricultural practices strongly influence the biodiversity of agricultural areas, and the ecological services that these ecosystems provide. One of the services that have been most affected is the biological resistance to pests.</div><div>Wine production is a common type of agriculture throughout the world, and it has a strong historical and economic importance for certain countries such as Portugal. But this type of agriculture is subject a high number of pests that affect the production, and farmers use pesticides to combat these pests, thus affecting the biodiversity that inhabits and uses the vineyards for food. </div><div>This study took place in the Bairrada region in Central Portugal. We used six vineyards to assess the losses caused by fungi, birds and insects in four castes (Touriga, Baga, Arinto and Chardonnay), and evaluated whether pests have a preference for any caste or color (white and red). Bird and insect communities were studied and divided into functional guilds (pest, neutral or auxiliary), to compare with grape losses and assess if these natural communities hold a potential to naturally control wine pests (biotic resistance hypothesis). The edge effect in grape losses was also evaluated. </div><div>We recorded a small proportion of grape losses, but we verified that insects had a preference for the Baga and Chardonnay castes. We observed that color did not influence the birds and insect's losses. In relation to the fungi losses, we registered a preference for the caste Baga. Most insects and birds observed in vineyards were pests, which entails a low level of biological control in this agricultural ecosystem. Although the relation between the edge and grape losses was not significant, there were more losses in the first 100 meters from the edge.</div><div>Further studies will be necessaries to fully evaluate the role of local biodiversity in vineyards. To better evaluate the biotic resistance hypothesis it would be necessary to sample an organic vineyard, i.e. without the use of the pesticides.</div><div><br></div

Pollination networks from natural and anthropogenic-novel communities show high structural similarity

The Anthropocene is marked by an unprecedented homogenisation of the world's biota, confronting species that never co-occurred during their evolutionary histories. Interactions established in these novel communities may affect ecosystem functioning; however, most research has focused on the impacts of a minority of aggressive invasive species, while changes inflicted by a less conspicuous majority of non-invasive alien species on community structure are still poorly understood. This information is critical to guide conservation strategies, and instrumental to advance ecological theory, particularly to understand how non-native species integrate in recipient communities and affect the interactions of native species. We evaluated how the structure of 50 published pollination networks changes with the proportion of alien plant species and found that network structure is largely unaffected. Although some communities were heavily invaded, the proportion of alien plant species was relatively low (mean = 10%; max. = 38%). We further characterized the pollination network in a botanic garden with a plant community dominated by non-invasive alien species (85%). We show that the structure of this novel community is also not markedly different from native-dominated communities. Plant-pollinator interactions revealed no obvious differences regarding plant origin (native vs. alien) or the native bioregion of the introduced plants. This overall similarity between native and alien plants is likely driven by the contrasting patterns of invasive plants (promoting generalism), and non-invasive aliens, suggested here to promote specialization

Distribution of genetic diversity (mitochondrial <i>cytochrome oxidase II</i> (<i>COII</i>) sequences) of <i>Xylocopa darwini</i> across the Galápagos Islands.

<p>(A) Distribution of mitochondrial haplotypes within populations (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120597#pone.0120597.s003" target="_blank">S1 Table</a>). (B) Distribution of haplotypes across islands. (C) Statistical parsimony network of haplotypes; lines represent single nucleotide substitutions, and dots indicate missing haplotypes (extinct or not found). Circle sizes are proportional to the number of sequences obtained for each haplotype.</p

Metrics used to infer inter-island colonization success of animal and plant species within the Galápagos, Azores and Canary Islands.

<p>¹ Number of current islands colonized by each species based on chorological data; (number of archipelago largest islands)</p><p>² Number of haplotypes obtained from mitochondria (animals) and plastid (plants) DNA sequences in each study</p><p>³ Number of haplotypes obtained in each study multiplied by the number of all largest islands-1</p><p>⁴ Inter-island colonization events based on distribution of each haplotype, i.e. each colonization event is inferred by haplotype sharing on two or more islands</p><p>⁵ Ratio expressing multiple colonization events, that ranges between 1 (all islands colonized by all the haplotypes) and 0 (no inter-island colonization).</p><p>* <i>Olea europaea</i> subsp. <i>guanchica</i> is distributed across the seven Canary Islands. However, the three eastern-most islands show evidence for hybridization with the olive tree. This made the authors use only material from the four western-most islands.</p><p>Metrics used to infer inter-island colonization success of animal and plant species within the Galápagos, Azores and Canary Islands.</p