Next Article in Journal
Irregular Shelterwood Cuttings Promote Viability of European Yew Population Growing in a Managed Forest: A Case Study from the Starohorské Mountains, Slovakia
Previous Article in Journal
Estimation of Forest Biomass Patterns across Northeast China Based on Allometric Scale Relationship
Open AccessArticle

Mapping Tree Density in Forests of the Southwestern USA Using Landsat 8 Data

Department of Natural Resources Management, Goddard Building, Texas Tech University, Box 42125, Lubbock, TX 79409, USA
U.S. Geological Survey, New Mexico Cooperative Fish and Wildlife Research Unit, Department of Fish, Wildlife and Conservation Ecology, New Mexico State University, Las Cruces, NM 88003, USA
Author to whom correspondence should be addressed.
Forests 2017, 8(8), 287;
Received: 1 July 2017 / Revised: 1 August 2017 / Accepted: 4 August 2017 / Published: 9 August 2017
The increase of tree density in forests of the American Southwest promotes extreme fire events, understory biodiversity losses, and degraded habitat conditions for many wildlife species. To ameliorate these changes, managers and scientists have begun planning treatments aimed at reducing fuels and increasing understory biodiversity. However, spatial variability in tree density across the landscape is not well-characterized, and if better known, could greatly influence planning efforts. We used reflectance values from individual Landsat 8 bands (bands 2, 3, 4, 5, 6, and 7) and calculated vegetation indices (difference vegetation index, simple ratios, and normalized vegetation indices) to estimate tree density in an area planned for treatment in the Jemez Mountains, New Mexico, characterized by multiple vegetation types and a complex topography. Because different vegetation types have different spectral signatures, we derived models with multiple predictor variables for each vegetation type, rather than using a single model for the entire project area, and compared the model-derived values to values collected from on-the-ground transects. Among conifer-dominated areas (73% of the project area), the best models (as determined by corrected Akaike Information Criteria (AICc)) included Landsat bands 2, 3, 4, and 7 along with simple ratios, normalized vegetation indices, and the difference vegetation index (R2 values for ponderosa: 0.47, piñon-juniper: 0.52, and spruce-fir: 0.66). On the other hand, in aspen-dominated areas (9% of the project area), the best model included individual bands 4 and 2, simple ratio, and normalized vegetation index (R2 value: 0.97). Most areas dominated by ponderosa, pinyon-juniper, or spruce-fir had more than 100 trees per hectare. About 54% of the study area has medium to high density of trees (100–1000 trees/hectare), and a small fraction (4.5%) of the area has very high density (>1000 trees/hectare). Our results provide a better understanding of tree density for identifying areas in need of treatment and planning for more effective treatment. Our analysis also provides an integrated method of estimating tree density across complex landscapes that could be useful for further restoration planning. View Full-Text
Keywords: fire suppression; tree density; Landsat 8; wildfire; restoration; Jemez mountains fire suppression; tree density; Landsat 8; wildfire; restoration; Jemez mountains
Show Figures

Figure 1

MDPI and ACS Style

Humagain, K.; Portillo-Quintero, C.; Cox, R.D.; Cain, J.W., III. Mapping Tree Density in Forests of the Southwestern USA Using Landsat 8 Data. Forests 2017, 8, 287.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop