scholarly journals Factors Influencing the Geographical Distribution of Dendroctonus armandi (Coleoptera: Curculionidae: Scolytidae) in China

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 425
Author(s):  
Hang Ning ◽  
Lulu Dai ◽  
Danyang Fu ◽  
Bin Liu ◽  
Honglin Wang ◽  
...  
Keyword(s):  
Current Distribution ◽  
Species Distribution Models ◽  
Northern China ◽  
Climatic Conditions ◽  
Southwestern China ◽  
Qinling Mountains ◽  
Distribution Models ◽  
Temperature And Precipitation ◽  
Scale Levels ◽  
The Mean

In order to prevent any further spread of Dendroctonus armandi (Coleoptera: Curculionidae: Scolytidae), it is important to clarify its geographic distribution in China. Species Distribution Models were used to identify the variables influencing the distribution of D. armandi in China, and to create maps of its distribution. D. armandi almost exclusively attacked Pinus armandi Franch (IP (frequency of its incidence) = 98.2%), and its distribution is focused on the Qinling Mountains and the Ta-pa Mountains. The current distribution of P. armandi does not limit the distribution of D. armandi, despite the host occurring in in northern and southwestern China. Temperature and precipitation limit the current distribution of this beetle. The mean temperature of coldest quarter (−5 °C) does not guarantee that D. armandi larvae can overwinter in northern China, and the precipitation of wettest quarter plays an important role in the dispersal and colonization of D. armandi adults in southwestern China. Therefore, the ecological niche of this beetle is relatively narrow when it comes to these environmental variables. The climatic conditions where this beetle inhabit are different from the prevalent climate in the Qinling Mountains and the Ta-pa Mountains. At the meso- and micro-scale levels, terrain variables create habitat selection preferences for D. armandi. D. armandi predominately colonizes trees on the southern slopes of valleys and canyons with elevations between 1300 m a.s.l and 2400 m a.s.l.

scholarly journals Constructing ecological indices for urban environments using species distribution models

2021 ◽  
Author(s):  
Ariel Levi Simons ◽  
Stevie Caldwell ◽  
Michelle Fu ◽  
Jose Gallegos ◽  
Michael Gatheru ◽  
...  
Keyword(s):  
Los Angeles ◽  
Species Distribution ◽  
Indicator Species ◽  
Environmental Conditions ◽  
Native Species ◽  
Species Distribution Models ◽  
Urban Environments ◽  
Ecological Indices ◽  
Distribution Models ◽  
The Mean

Abstract In an increasingly urbanized world, there is the need for a framework to assess ecological conditions in these anthropogenically dominated environments. Using species observations from the Global Biodiversity Information Facility (GBIF), along with remotely sensed environmental layers, we used MaxEnt to construct species distribution models (SDMs) of native and non-native species in Los Angeles. 25 native and non-native Indicator species were selected based on the sensitivities of their SDM, as measured by the Symmetric Extremal Dependence Index (SEDI), to environmental gradients. These SDMs were summarized to produce ecological indices of native and non-native biodiversity in Los Angeles. We found native indicator species to have a greater sensitivity to environmental conditions than their non-native counterparts, with the mean SEDI score of native and non-native species MaxEnt models being 0.72 and 0.71 respectively. While both sets of species were sensitive to land use categories and housing density, native species were more sensitive to natural landscape variables while non-native ones were more sensitive to measures of water and soil contamination. Using random forest modeling we also found our native index could be more reliably predicted, given environmental conditions, than its non-native counterpart. The mean Pearson correlation between actual and predicted index values were 0.86 and 0.84 for native and non-native species. From these results we conclude that using SDMs to predict the biodiversity of environmental species is a suitable approach towards evaluating ecological conditions in urban environments, with the environmental sensitivity of native SDMs outperforming non-native ones.

Stoichiometric characteristics of different agroecosystems under the same climatic conditions in the agropastoral ecotone of northern China

Soil Research ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 875
Author(s):  
Xiajie Zhai ◽  
Kesi Liu ◽  
Deborah M. Finch ◽  
Ding Huang ◽  
Shiming Tang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Layer ◽  
Soil Nutrient ◽  
Northern China ◽  
Climatic Conditions ◽  
N:P Ratios ◽  
C:P Ratio ◽  
The Mean ◽  
Natural Grassland

Ecological stoichiometry affects the processes and functions of ecosystems, but the similarities and differences of stoichiometric characteristics among diverse agropastoral ecosystems under the same climatic conditions remain unclear. In this study, plant and soil stoichiometric characteristics of different agroecosystems, namely natural grassland (free-grazing and mowed grassland), artificial grassland (oat, Chinese leymus and corn silage), field crops (naked oats, flax and wheat) and commercial crops (cabbage and potatoes), were investigated in Guyuan County, China. Results showed total nitrogen (TN), total phosphorus (TP) and N:P ratios in plant tissue varied significantly among ecosystem types (P < 0.05). In general, the mean soil organic carbon, TN and TP content in the 0–0.3 m soil layer in potatoes (8.01, 1.05 and 0.33 g kg–1 respectively) were significantly lower than in other agroecosystems (P < 0.05). The mean C:N ratios of the 0–0.3 m soil layer did not differ significantly among the agroecosystems (P > 0.05). However, the C:P ratio was lower in potato than cabbage sites (24.64 vs 33.17), and was lower at both these sites than in other agroecosystems (P < 0.05). With regard to N:P ratios, only the potato ecosystem had lower values than in other ecosystems (P < 0.05), which did not differ significantly (P > 0.05). Above all, N is more likely to be limiting than P for biomass production in local agroecosystems. Soil C:P and N:P ratios decreased significantly with an increase in the utilisation intensity (from natural grassland to commercial crop). The findings of this study suggest that restoring, preserving and increasing soil organic carbon (especially for cabbage and potatoes), scientifically adjusting the application of N and P fertiliser and enhancing subsidies for low-loss soil nutrient systems, such as grassland, rather than commercial crops will help improve and sustain agroecosystems.

Coral reef fishes reveal strong divergence in the prevalence of traits along the global diversity gradient

2021 ◽  
Vol 288 (1961) ◽  
Author(s):  
V. Parravicini ◽  
M. G. Bender ◽  
S. Villéger ◽  
F. Leprieur ◽  
L. Pellissier ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Species Distribution Models ◽  
Human Impacts ◽  
Biodiversity Loss ◽  
Reef Fishes ◽  
Climatic Conditions ◽  
Taxonomic Structure ◽  
Distribution Models ◽  
Diversity Gradient ◽  
And Shifts

Coral reefs are experiencing declines due to climate change and local human impacts. While at a local scale these impacts induce biodiversity loss and shifts in community structure, previous biogeographical analyses recorded consistent taxonomic structure of fish communities across global coral reefs. This suggests that regional communities represent a random subset of the global species and traits pool, whatever their species richness. Using distributional data on 3586 fish species and latest advances in species distribution models, we show marked gradients in the prevalence of size classes and diet categories across the biodiversity gradient. This divergence in trait structure is best explained by reef isolation during past unfavourable climatic conditions, with large and piscivore fishes better represented in isolated areas. These results suggest the risk of a global community re-organization if the ongoing climate-induced reef fragmentation is not halted.

scholarly journals Regional Climate Change (Karelia, Russia)

2015 ◽  
Vol 2 ◽  
pp. 356
Author(s):  
Larisa Nazarova
Keyword(s):  
Air Temperature ◽  
Global Climate ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Climatic Conditions ◽  
Temperature And Precipitation ◽  
The Mean ◽  
Weather Stations ◽  
Meteorological Observations ◽  
Mean Annual Air Temperature

The overview of climatic conditions in Karelia is based on the data from meteorological observations carried out in 1951-2009 at Roskomgidromet weather stations situated in the study area. Taking the period in question into account, the mean annual air temperature norm has increased by 0.2-0.3°C. The greatest deviation from multiyear averages of mean monthly air temperature is observed in January and March. The investigation of the changes the basic regional climate characteristics is very important in present time because the global climate is changed. The analysis the data about air temperature and precipitation, that were obtained for the different meteorological stations in the investigated region, shows that the regional climate is changed and the main tendencies are directly proportional to the change of the global characteristics.

scholarly journals Estimation of Urbanization Impacts on Local Weather: A Case Study in Northern China (Jing-Jin-Ji District)

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 797 ◽  
Author(s):  
Hui-Dong Su ◽  
Xuejian Cao ◽  
Da-Cheng Wang ◽  
Yang-Wen Jia ◽  
Guangheng Ni ◽  
...  
Keyword(s):  
Large Population ◽  
Management Strategies ◽  
Wrf Model ◽  
Single Layer ◽  
Northern China ◽  
Maximum Temperature ◽  
Rapid Urbanization ◽  
Temperature And Precipitation ◽  
The Mean ◽  
Local Weather

With the past rapid economic development and large population growth, Jing-Jin-Ji District has been undergoing rapid urbanization, which has caused considerable regional weather changes in local regions. In this paper, we used the Weather Research and Forecasting (WRF) model to quantitatively analyze the effects of past urbanization and potential future urbanization on the regional weather in the center of Jing-Jin-Ji District. The hydrometeorological data from two weeks in July 2019 were used to simulate the influence of urbanization on local weather in the Jing-Jin-Ji District at regional scales using a single-layer canopy parameterization scheme. To better quantify the differences in temperature and precipitation induced by urbanization, three simulation scenarios were designed, which were no urban cover (NU), current urbanization cover (CU), and full urban land cover (FU), respectively. The results showed that: (1) Urbanization progress (from NU to CU and from CU to FU) in Jing-Jin-Ji District increased the daytime temperature, night temperature, and temperature difference between day and night, while decreasing the total rainfall and peak rainfall. (2) Compared with NU, the mean temperature of the CU and FU increased 0.3 K and 0.6 K, respectively, and the mean precipitation of CU and FU decreased by approximately 6% and 8.4%, respectively. (3) The main influence of urbanization on weather was reflected by the maximum temperature and peak rainfall, while the other impacts were relatively insignificant. (4) Compared with NU, the maximum temperature of CU and FU increased 0.82 K and 1.35 K, respectively, and the peak rainfall of NU and FU decreased by approximately 9.5% and 19.0%, respectively; The results of this study bring to light the urban management strategies for policy makers.

scholarly journals The influence of surface characteristics, topography, and continentality on mountain permafrost in British Columbia

2014 ◽  
Vol 8 (5) ◽  
pp. 4779-4822 ◽  
Author(s):  
A. Hasler ◽  
M. Geertsema ◽  
V. Foord ◽  
S. Gruber ◽  
J. Noetzli
Keyword(s):  
British Columbia ◽  
Snow Cover ◽  
Air Temperature ◽  
Climatic Factors ◽  
Small Variation ◽  
Surface Characteristics ◽  
Climatic Conditions ◽  
Distribution Models ◽  
The Mean ◽  
Cover Thickness

Abstract. Thermal offset and surface offset are terms that describe the deviation of the mean annual ground temperature from the mean annual air temperature. These offsets are controlled by surface characteristics and topo-climatic factors on a micro- and meso-scales. Macro-climatic conditions may, however, influence the effectiveness of the responsible processes. Existing knowledge on surface- and topography-specific offsets is not easily transferable and limits the applicability of empirical permafrost distribution models over large areas with macro-climatic gradients. In this paper we describe surface and thermal offsets derived from distributed measurements at seven field sites in British Columbia. Key findings are (i) a surprisingly small variation of the surface offsets between different surface types and small thermal offsets in general (excluding wetlands and peat), (ii) a clear influence of the micro-topography at wind exposed sites (snow cover erosion), (iii) a north–south difference of the surface offset of 4 °C in near-vertical bedrock and of 1.5–3 °C on open (no canopy) gentle slopes, (iv) only small macro-climatic differences caused by the reverse influence of snow cover thickness and annual air temperature amplitude. These findings suggest, that empirical permafrost models based on topo-climatic variables may be applicable across regions with significant macro-climatic differences.

scholarly journals Comparing six different species distribution models with several subsets of environmental variables: Predicting the potential current distribution of Guettarda speciosa in Indonesia

2019 ◽  
Vol 20 (8) ◽  
Author(s):  
Angga Yudaputra ◽  
Inggit Puji Astuti ◽  
Wendell P. Cropper
Keyword(s):  
Distribution Pattern ◽  
Predictive Model ◽  
Species Distribution ◽  
Current Distribution ◽  
Predictive Models ◽  
Environmental Variables ◽  
Potential Distribution ◽  
Species Distribution Models ◽  
Distribution Models ◽  
Predictive Map

Abstract. Yudaputra A, Pujiastuti I, Cropper Jr. WP. 2019. Comparing six different species distribution models with several subsets of environmental variables: predicting the potential current distribution of zebra Guettarda speciosa in Indonesia. Biodiversitas 20: 2321-2328. There are many algorithms of species distribution modeling that widely used to predict the potential distribution pattern of diverse organisms. Finding the best model in terms of predicting the potential distribution of many species remains a challenge. The objective of this study is to compare six different algorithms for predicting the potential current distribution pattern of Guettarda speciosa (zebra wood). The occurrence records of G. speciosa are derived from herbarium database, Bogor Botanic Gardens’s plant inventory database and direct field surveys through NKRI expedition.  Seven climatic variables and elevation data are extracted from global data. R open-source software is used to run those algorithms and QGIS is used to prepare the spatial data.  The result shows that MAXENT outperforms other predictive models with the highest AUC score 0.89, followed by SVM (0.87), RF (0.86), and GLM (0.82), DOMAIN (0.73), and BIOCLIM (0.62). Based on the AUC score, the four predictive models (MAXENT, SVM, RF, GLM) are categorized into good predictive models, indicating those are quite better to predict the potential current distribution pattern of G. speciosa. Whereas, DOMAIN is fair predictive model and BIOCLIM is poor predictive model. The predictive map derived from four models (MAXENT, SVM, RF, and GLM) shows almost similar appearance in predicting of potential current distribution of G. speciosa. The predictive map of current distribution would be useful to provide information regarding the potential habitat of G. speciosa across the landscape of Indonesia.

scholarly journals Projected impact of global warming on the distribution of two pocket mouse species with implications on the conservation of Heteromys nelsoni (Rodentia: Heteromyidae)

2019 ◽  
Vol 67 (6) ◽  
Author(s):  
Consuelo Lorenzo ◽  
Arturo Carrillo-Reyes ◽  
Tamara Rioja-Paradela ◽  
Eugenia Sántiz-López ◽  
Jorge Bolaños-Citalán
Keyword(s):  
Climate Change ◽  
Potential Distribution ◽  
Conservation Status ◽  
Climatic Conditions ◽  
Suitable Habitat ◽  
Distribution Models ◽  
Altitudinal Range ◽  
Temperature And Precipitation ◽  
Area Of Occupancy ◽  
Pocket Mouse

We explain through potential distributions and changes in altitudinal variation, the possible impacts of climate change in an endangered micro-endemic rodent of Mexico with narrow altitudinal range, Heteromys nelsoni and a rodent with a wide distributional and altitudinal range, Heteromys goldmani. We obtained historical and current records of both Heteromys species. Potential distribution models were generated using Maxent, including altitudes for each species and bioclimatic layers. We determined the Extent of Occurrence and Area of Occupancy for H. nelsoni according to the criteria of the IUCN in order to generate information about its risk status. The altitude is not a variable that determines a shift in the distribution caused by climate change. In contrast, the temperature and precipitation are important for the potential distribution of both Heteromys species. The future changes in climatic conditions will reduce the area of suitable habitat for H. nelsoni and will favor the presence of H. goldmani. The distribution surface is not greater than 33.44 km2 for H. nelsoni. Therefore, is urgent to re-evaluate their conservation status by the IUCN, mainly in its B criterion, and to take specific actions for their conservation. We suggest the creation of a terrestrial protected area.

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