Data on ecological associations and stand structure of chilgoza pine (Pinus gerardiana Wall. ex D. Don) in Afghanistan

Reported here are original data related to the article “Indigenous knowledge and stand characteristics of a threatened tree species in a highly insecure area: Chilgoza pine in Afghanistan” (Shalizi et al., 2018) [1]. A dendrochronological summary of all known chilgoza pine tree growth increment cores collected in Afghanistan is presented in this data in brief article. Chilgoza pine trees and regeneration density profiles are reported for four provinces of eastern Afghanistan. In addition, images depicting chilgoza pine forest structure, stand conditions, and utilization impacts are presented.


a b s t r a c t
Reported here are original data related to the article "Indigenous knowledge and stand characteristics of a threatened tree species in a highly insecure area: Chilgoza pine in Afghanistan" (Shalizi et al., 2018) [1]. A dendrochronological summary of all known chilgoza pine tree growth increment cores collected in Afghanistan is presented in this data in brief article. Chilgoza pine trees and regeneration density profiles are reported for four provinces of eastern Afghanistan. In addition, images depicting chilgoza pine forest structure, stand conditions, and utilization impacts are presented.
& The data are available with this article.

Value of the data
The data provide first-ever scientific information on an infrequently studied and economically important tree species from an insecure region of the world.
These data can be used as a foundation for future studies helpful toward sustaining the chilgoza pine resource in Afghanistan.
These data offer the basis for the first published description of chilgoza pine stand dynamics in Afghanistan.

Data
The data in this article are divided into two parts. Part one provides quantitative data collected from site measurements representing 17 sampling plots across six districts in four provinces in the Eastern Forest Complex of Afghanistan. These data consist of stand density (tree and seedling/saplings per hectare) and tree growth increment core data (height, diameter at breast height (dbh), and pith date). A summary of chilgoza pine tree and natural regeneration density is presented in Fig. 1. In addition, tree and seedling/sapling density at each sampling plot is represented in Figs. 2 and 3. Raw data of stand density can be found in Excel file 1. Chilgoza dbh histograms and basal area boxplot are presented in Figs. 4 and 5. Scatterplots of the relationship between dbh, height, and pith date are

Experimental design, materials and methods
Stand density and natural regeneration data were collected from 17 fixed-area circular plots (radius of 12.6 m ¼ 500 m 2 ). The plots were located at six districts (4 in Musakhel, 4 in Qalandar, 4 in Urgun, 2 in Zazai Aryob, 2 in Ahmadkhel, and 1 in Alisheng) of four provinces (Khost, Paktika, Paktia, and Laghman) in the eastern forest complex of Afghanistan. Within each district, the sampling plots were established randomly, 1-5 km apart. Within each plot, dbh (diameter at 1.37 m) of the largest chilgoza tree in each plot was measured with a diameter tape. Additionally, the total number of trees      9. Mixed chilgoza-deodar cedar forest in Urgun district, Paktika province. Note the size of gaps between trees is much larger than the wetter site in Fig. 8.   by species were recorded based on two size categories; tree ( 4 5 cm dbh) and seedling/sapling (r 5 cm, ground line diameter).
Tree cores, dbh, and height data for live dominant trees were collected at one site each in Paktia (Shawat, Sayid Karam and Mirzaka) in October, 2009 and Paktika (Sarobi) in August, 2009 using a tree increment borer, diameter tape, and clinometer, respectively. Some tree heights were measured using photogrammetric image analysis if field time was insufficient for clinometer measurements. Increment cores were processed in the Forest History Laboratory at Southern Illinois University using standard dendroecological methods including air drying, mounting, sanding, and cross-dating cores [2]. Pith dates were determined using standard skeleton plots and visual cross-dating methods [2]. Images were taken by field surveyors with a camera or mobile phone camera.

Stand density data
Tree and seedling/sapling density data of chilgoza pine were summarized for six districts and are presented in Fig. 1. Trees and seedling/sapling density data for major tree species across 17 measurement plots are presented in Figs. 2 and 3.

Tree core data
Dbh distribution of chilgoza is presented as histograms in Fig. 4 and basal area is presented in Fig. 5. Scatterplots of height vs. dbh relationship and pith date vs. dbh relationship are given in Figs. 6 and 7 respectively.

Images
The images (Figs. 8-11) provide a general view of chilgoza pine forest structure and signs of wood removal in the eastern forest complex of Afghanistan. Figs. 12 and 13 illustrate site measurements accomplished by local surveyor and international scientists with the help of military personnel.