ABoVE: Characterization of Carbon Dynamics in Burned Forest Plots, NWT, Canada, 2014
简介
文件修订日期：2019-04-12
数据集版本: 1
摘要
该数据集提供了加拿大西北地区（NWT）2014 年被野火烧毁的北方森林的实地数据。在 2015 年的实地考察中，共建立了 211 个烧毁地块。从这些地块中选出了 32 块以黑云杉为主的森林地块，这些地块代表了整个地貌的全部湿度梯度，从干旱到次干旱不等。地块观测包括坡度、坡向和湿度。在每个地块，选择一个与特定燃烧深度相关的完整有机土壤剖面，分析特定剖面深度增量的碳含量和放射性碳（14C）值，以评估遗留碳的存在和燃烧情况。植被观测包括树木密度。火灾发生时的树龄是通过树环计数确定的。得出火灾前地下和地上碳库的估计值。估算了西北地区野火烧毁的总面积中 "年轻 "林分（火灾时树龄小于 60 年）所占的百分比。
野外地块于 2015 年夏季在七个空间上独立的烧伤疤痕处建立，其中四个位于泰加平原生态区，三个位于泰加盾生态区。根据西北部北方森林 70-130 年的历史火灾重现间隔，将地块分为年轻烧毁地块（火灾发生时林龄小于 60 年，平均值=45 年）和老龄烧毁地块（火灾发生时林龄大于 70 年，平均值=128 年）。在每个剖面中，使用多个相邻土壤深度增量的 Δ14C 值将其归入大气弹峰的正确一侧，并与林分建立当年的大气 Δ14CO2 值进行比较。土壤和林分 Δ14C 之间的关系用于评估遗留碳的存在和燃烧情况。如果基质土壤样本的年龄大于火灾发生时的林分年龄，则认为存在遗留碳；如果残留表层土壤样本的年龄大于火灾发生时的林分年龄，则认为遗留碳已燃烧。
该数据集有三个逗号分隔（.csv）格式的数据文件。
大气中的放射性碳浓度（delta14C）随时间变化的情况，显示了 1966 年的炸弹峰值（红色虚线）和土壤深度增量 delta14C 的理论位置（点）（沃克等人，2019 年）。
项目北极-北方脆弱性实验
北极-北方脆弱性实验（ABoVE）是美国国家航空航天局（NASA）陆地生态计划在 2016 年至 2021 年期间在阿拉斯加和加拿大西部开展的一项实地活动。ABoVE 的研究将基于实地的过程级研究与机载和卫星传感器获得的地理空间数据产品联系起来，为提高分析和建模能力奠定了基础，而分析和建模能力是了解和预测生态系统反应及社会影响所必需的。
数据特征
空间覆盖范围：加拿大西北地区
上方参考位置：
域：核心 ABoVE
州/地区： 加拿大西北地区加拿大西北地区
网格单元：Ah2v1Bh13Bv9Ch79Cv59, Ah2v1Bh14Bv10Ch84Cv61, Ah2v1Bh13Bv10Ch83Cv65, Ah2v1Bh14Bv10Ch84Cv65, Ah2v1Bh13Bv11Ch78Cv66, Ah2v1Bh12Bv11Ch77Cv68, Ah2v1Bh13Bv11Ch78Cv68, Ah2v1Bh12Bv11Ch75Cv71
空间分辨率：多点
时间覆盖范围：2015 年夏季建立田间地块
时间分辨率：一次性
研究区域： 所有经纬度均以十进制度表示。
研究区样本点
| Site | Westernmost Longitude | Easternmost Longitude | Northernmost Latitude | Southernmost Latitude |
|---|---|---|---|---|
| Northwest Territories, Canada | -117.505 | -113.7326705 | 64.161929 | 60.9377645 |
西北地区估计烧毁面积范围的坐标（NWT_Young_Burned_Area.csv）。
| Site | Westernmost Longitude | Easternmost Longitude | Northernmost Latitude | Southernmost Latitude |
|---|---|---|---|---|
| Northwest Territories, CA | -136.119 | -102 | 71.69472 | 56.25417 |
数据文件信息
该数据集有三个逗号分隔格式（.csv）的数据文件。
文件名和说明
| Variable | Units | Description |
|---|---|---|
| burned_site_plot | Plot from which soil sample was obtained. Plot name represents the burn from which sample was collected (SS33=Kakisa, ZF20=CentralHwy3, ZF46=NorthernHwy3, ZF35=Gameti West, ZF44=Gameti East, ZF26=Wekweeti, ZF104-Discovery Mine) and the plot number. | |
| latitude | decimal degrees | Latitude at start of west transect from GPS |
| longitude | decimal degrees | Longitude at start of west transect from GPS |
| sample_transect | The meter along the transect from which the soil profile was obtained | |
| sample_monolith | The monolith number (1 or 2) obtained at each plot. In 27 plots one monolith was collected and in 5 plots two monoliths were collected | |
| site_sample_transect | The combined identification of site and meter | |
| soil_depth_increment | cm | Depth (cm) of the soil depth increment |
| increment_location | Location of the soil depth increment (TOP = either 1 cm or 2cm depth increments, BOTTOM = depth increment of variable depth - located directly above the mineral soil or at the thaw front) | |
| bottom_sol_material | Category of what the bottom of the soil organic layer profile hit (min=mineral soil; ice= frozen organic soil) | |
| field_sample_id | A sample identification of the soil depth increment sent for radiocarbon analysis | |
| uciams_id | Sample identification given by University of California, Irvine's W.M. Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory, where radiocarbon samples were analyzed. | |
| Delta14C | ‰ | Delta 14C of the sample (the per mil (‰) difference between the 14C/12C ratio of the sample and an international standard). Calculated as described by Stuiver and Polach (1977) |
| std_deviation | Error of Delta 14C measurement. The standard deviation of approximately 10 repetitive measurements of the sample. | |
| soil_class_pre-post_bomb | Soil increment classification based on atmospheric bomb peak (pre = pre bomb peak; post=post bomb peak) | |
| stand_age_rings | Age of the stand at time of fire based on the number of tree rings, 5 black spruce trees were sampled at each site (these data are also provided in the file Radiocarbon_site_data.csv for user convenience) | |
| stand_year | YYYY | The year that the stand established (2014-stand_age_rings) |
| X14C_yr_stand_age | ‰ | The atmospheric concentration of Delta 14C in the year that the stand established |
| stand_age_pre-post_bomb | Stand age classification based on atmospheric bomb peak (pre = pre bomb peak; post = post bomb peak) |
文件 Radiocarbon_site_data.csv 中的变量
| Variable | Units | Description |
|---|---|---|
| burned_site_plot | Plot from which soil sample was obtained. Plot name represents the burn from which it was sampled (SS33=Kakisa, ZF20=CentralHwy3, ZF46=NorthernHwy3, ZF35=Gameti West, ZF44=Gameti East, ZF26=Wekweeti, ZF104-Discovery Mine) and the plot number. All plots are labelled A - because they were selected using a random stratified sampling design. | |
| latitude | decimal degrees | Latitude at start of west transect from GPS |
| longitude | decimal degrees | Longitude at start of west transect from GPS |
| elevation | masl | Elevation at start of west transect from GPS. Meters above sea level |
| slope | degrees | Slope in degrees. A slope <5 was given a 0 |
| aspect | degrees | Slope aspect in compass degrees (0 to 360) - has not been corrected for declination. -9999 indicates there is no slope >5 |
| moisture_johnstone | Ranking of plot moisture potential using the moisture key presented in the successional trajectories workbook (Johnstone et al. 2008). Values range from 1 to 6, where 1=xeric, 2=subxeric, 3=subxeric to mesic, 4=mesic, 5=submesic, 6=subhygric | |
| moisture_class | Ranking of plot moisture potential from original rankings (moisture_johnstone). Dry=xeric and sub-xeric; Moist=subxeric-mesic and mesic; Wet=sub-mesic and subhygric | |
| stand_age_rings | Stand age at the time of fire, based on tree ring counts from 5 black spruce trees per site (these data are also provided in the file Soil_radiocarbon_data.csv for user convenience) | |
| stand_age_class | Stand age classification based on the age of stand at the time of fire (young= <60 years at time of fire; old = >70 years at time of fire) | |
| residual_sol_depth | cm | Mean of organic layer depth (cm) located along the transect (10 points) |
| burn_depth | Depth of burn calculated by adventitious root height and an associated unburned offset (see Walker et al. 2018a) | |
| prefire_sol_depth | cm | Depth of prefire soil organic layer (SOL) (cm). Calculated by adding burn depth to residual soil organic layer depth |
| bg_c_residual | g/m2 | Residual belowground carbon content (g C m2) |
| bg_c_combusted | g/m2 | Belowground carbon combusted (g C m2). Based on model of carbon content as a function of depth and depth of burn |
| prefire_bg_c | g/m2 | Prefire belowground carbon content (g C m2). Sum of belowground carbon combusted + residual belowground carbon (see Walker et al., 2018b for models) |
| tree_density | Number stems/m2 | Estimated density of Picea mariana stems per m2 for the pre-fire stand. Sample area was 60 sq. m. All trees and saplings that were alive at the time of the 2014 fires are included |
| tree_c_prefire | g/m2 | Aboveground carbon prefire (g C m2) |
文件 NWT_Young_Burned_Area.csv 中的变量
| Column name | Units | Description |
|---|---|---|
| Year_of_burn | YYYY | Year of burn (YYYY) |
| year_since_fire | Years since the fire/s | |
| percent_reburned | % | Percent of area reburned |
| cumulative | Cumulative percent young-burned |
应用与推导
这些数据让我们了解到北方森林火灾对全球碳动态的影响。
数据采集、材料和方法
研究区域涵盖泰加平原和泰加盾牌两个生态区的部分地区，这两个生态区在地质历史、土壤发育和母质方面各不相同。在这两个生态区中，黑云杉林主要分布在质地细腻的冰川-岩溶土壤中，而松柏则主要分布在质地粗糙的冲积土和冰川-流积土中。在泰加地盾特有的裸露基岩上，密度较低的黑云杉和白皮松通常占主导地位。
代码
!pip install leafmap
!pip install pandas
!pip install folium
!pip install matplotlib
!pip install mapclassify
import pandas as pd
import leafmap
url = "https://github.com/opengeos/NASA-Earth-Data/raw/main/nasa_earth_data.tsv"
df = pd.read_csv(url, sep="\t")
df
leafmap.nasa_data_login()
results, gdf = leafmap.nasa_data_search(
short_name="ABoVE_Soil_Radiocarbon_NWT_1664",
cloud_hosted=True,
bounding_box=(-136.12, 56.25, -102.0, 71.69),
temporal=("2015-06-14", "2015-06-14"),
count=-1, # use -1 to return all datasets
return_gdf=True,
)
gdf.explore()
#leafmap.nasa_data_download(results[:5], out_dir="data")引用
Walker, X.J., J.L. Baltzer, W. Laurier, S.G. Cumming, N.J. Day, S.J. Goetz, J.F. Johnstone, S. Potter, B.M. Rogers, E.A.G. Schuur, M.R. Turetsky, and M.C. Mack. 2019. ABoVE: Characterization of Carbon Dynamics in Burned Forest Plots, NWT, Canada, 2014. ORNL DAAC, Oak Ridge, Tennessee, USA. ABoVE: Characterization of Carbon Dynamics in Burned Forest Plots, NWT, Canada, 2014, https://doi.org/10.3334/ORNLDAAC/1664
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