9 research outputs found
Remote sensing data can improve predictions of species richness by stacked species distribution models: A case study for Mexican pines
Aim: Remote sensing data have been used in a growing number of studies to directly predict species richness or to improve the performance of species distribution models (SDMs), but their suitability for stacked species distribution models (S-SDMs) remains unclear. In this case study, we evaluated the potential and limitations of remotely sensed data in S-SDMs and addressed the commonly observed overestimation of species richness by S-SDMs. Location: Mexico. Methods: Phenological and statistical metrics were derived from remotely sensed time series data (2001-2009) of the Terra-MODIS enhanced vegetation index and land surface temperature products. In a series of climatic and remote sensing-based SDMs, the distribution ranges of 40 species of the genus Pinus (Pinaceae) were modelled based on presence-only herbarium and field data using the maximum entropy algorithm and summed to estimate species richness. Three different species-specific thresholds were applied to convert continuous model predictions into binary maps. Modelled species richness was compared to independent data from the Mexican National Forest Inventory. Results: The inclusion of remote sensing data led to significantly better predictions of species richness in comparison to the climate-based models for the summed suitabilities and all thresholds considered. Both climatic and remote sensing-based models allowed us to identify the areas with the highest pine species richness based on presence-only data. Remote sensing-based models compare closely with climate-derived patterns, but provide better spatial resolution and more detailed information on local habitat availability. Main conclusions: The results of this case study provide general guidance for the potential and limitations of using remote sensing data in S-SDMs. Our results confirmed that remote sensing data may not only have the capability for improving individual SDMs, but also can be a potential tool for reducing the overestimation of species richness by S-SDMs. This approach opens up new possibilities for species richness predictions in areas where biological survey data are scarce and where no species richness inventory data exist. � 2013 John Wiley & Sons Ltd
Phylogenetic relationships of Pinus Subsection Ponderosae inferred from rapidly evolving cpDNA Regions
Pinus subsection Ponderosae includes approximately 17 tree species distributed from western Canada to Nicaragua. We inferred phylogenetic relationships of multiple accessions for all widely recognized species from 3.7 kb of cpDNA sequence (matK, trnD-trnY-trnE spacer, chlN-ycf1 spacer, and ycf1). The sister relationship between subsections Ponderosae and Australes was corroborated with high branch support, and several clades, most with lower branch support, were identified within subsection Ponderosae. Pinus jeffreyi was sister to P. coulteri, P. sabiniana, and P. torreyana. Californian accessions of P. ponderosa and P. washoensis occurred in a clade separate from P. arizonica and P. scopulorum from the southwestern United States. Western Mexican species P. cooperi and P. durangensis had cpDNA sequences identical to one or more accessions of P. arizonica and P. scopulorum, and together these taxa were closely related to clades of P. engelmannii-P. devoniana (Mexico) and P. douglasiana-P. yecorensis-P. maximinoi (western Mexico to Guatemala). A well supported clade of taxa from Mexico and Central America included P. pseudostrobus, P. montezumae, P. hartwegii, P. maximinoi (one of three accessions), P. nubicola, and P. donnell-smithii. Chloroplast DNA sequences were nonmonophyletic for most species, although the degree of support varied. © 2009 by the American Society of Plant Taxonomists
Pleiotrophin as a central nervous system neuromodulator, evidences from the hippocampus
Pinus subsection Ponderosae includes approximately 17 tree species distributed from western Canada to Nicaragua. We inferred phylogenetic relationships of multiple accessions for all widely recognized species from 3.7 kb of cpDNA sequence (matK, trnD-trnY-trnE spacer, chlN-ycf1 spacer, and ycf1). The sister relationship between subsections Ponderosae and Australes was corroborated with high branch support, and several clades, most with lower branch support, were identified within subsection Ponderosae. Pinus jeffreyi was sister to P. coulteri, P. sabiniana, and P. torreyana. Californian accessions of P. ponderosa and P. washoensis occurred in a clade separate from P. arizonica and P. scopulorum from the southwestern United States. Western Mexican species P. cooperi and P. durangensis had cpDNA sequences identical to one or more accessions of P. arizonica and P. scopulorum, and together these taxa were closely related to clades of P. engelmannii-P. devoniana (Mexico) and P. douglasiana-P. yecorensis-P. maximinoi (western Mexico to Guatemala). A well supported clade of taxa from Mexico and Central America included P. pseudostrobus, P. montezumae, P. hartwegii, P. maximinoi (one of three accessions), P. nubicola, and P. donnell-smithii. Chloroplast DNA sequences were nonmonophyletic for most species, although the degree of support varied. " 2009 by the American Society of Plant Taxonomists.",,,,,,"10.1600/036364409789271290",,,"http://hdl.handle.net/20.500.12104/43603","http://www.scopus.com/inward/record.url?eid=2-s2.0-70349525370&partnerID=40&md5=e5977451c1194b7238fb70623ceffed
Similar but not equivalent: Ecological niche comparison across closely-related Mexican white pines
Aim: In the face of global environmental change, identifying the factors that shape the ecological niches of species and understanding the mechanisms behind them can help to draft effective conservation plans. The differences in the ecological factors that shape species distributions may then help to highlight differences between closely related taxa. We investigate the applicability of ecological niche modelling and the comparison of species distributions in ecological niche space to detect areas with priority for biodiversity conservation and to analyse differences in the ecological niche spaces used by closely related taxa. Location: United States of America, Mexico and Central America. Methods: We apply ordination and ecological niche modelling techniques to assess the main environmental drivers of the distribution of Mexican white pines (Pinus: Pinaceae). Furthermore, we assess the similarities and differences of the ecological niches occupied by closely related taxa. We analyse whether Mexican white pines occupy similar or equivalent ecological niches. Results: All the studied taxa presented different responses to the environmental factors, resulting in a unique combination of niche conditions. Our stacked habitat suitability maps highlighted regions in southern Mexico and northern Central America as highly suitable for most species and thus with high conservation value. By quantitatively assessing the niche overlap, similarity and equivalency of Mexican white pines, our results prove that the distribution of one species cannot be implied by the distribution of another, even if these taxa are considered closely related. Main conclusions: The fact that each Mexican white pine is constrained by a unique set of environmental conditions, and thus, their non-equivalence of ecological niches has direct implications for conservation as this highlights the inadequacy of one-fits all type of conservation measure. � 2014 The Authors. Diversity and Distributions published by John Wiley & Sons Ltd
Pines
Pinus is the most important genus within the Family Pinaceae and also within the gymnosperms by the number of species (109 species recognized by Farjon 2001) and by its contribution to forest ecosystems. All pine species are evergreen trees or shrubs. They are widely distributed in the northern hemisphere, from tropical areas to northern areas in America and Eurasia. Their natural range reaches the equator only in Southeast Asia. In Africa, natural occurrences are confined to the Mediterranean basin. Pines grow at various elevations from sea level (not usual in tropical areas) to highlands. Two main regions of diversity are recorded, the most important one in Central America (43 species found in Mexico) and a secondary one in China. Some species have a very wide natural range (e.g., P. ponderosa, P. sylvestris). Pines are adapted to a wide range of ecological conditions: from tropical (e.g., P. merkusii, P. kesiya, P. tropicalis), temperate (e.g., P. pungens, P. thunbergii), and subalpine (e.g., P. albicaulis, P. cembra) to boreal (e.g., P. pumila) climates (Richardson and Rundel 1998, Burdon 2002). They can grow in quite pure stands or in mixed forest with other conifers or broadleaved trees. Some species are especially adapted to forest fires, e.g., P. banksiana, in which fire is virtually essential for cone opening and seed dispersal. They can grow in arid conditions, on alluvial plain soils, on sandy soils, on rocky soils, or on marsh soils. Trees of some species can have a very long life as in P. longaeva (more than 3,000 years)