Canopy Photographs Research Articles

Using canopy height model derived from UAV imagery as an auxiliary for spectral data to estimate the canopy cover of mixed broadleaf forests.

Canopy cover is an important structural trait that is frequently used in forest inventories to assess sustainability as well as many other important aspects of forest stands. Remote sensing data is more effective and suitable for canopy cover estimating than traditional field measurements such as sample plots, especially at broad scales. Measurement and mapping this attribute in fine-scale is a difficult task. Aerial imagery using unmanned aerial vehicle (UAV) has been recognized as an excellent tool to estimate canopy attributes. In this study, we compared the potential of using digital hemispherical photography (DHP), digital cover photography (DCP), UAV RGB data, and canopy height model (CHM) for estimation of canopy cover of mix broad-leaved forest on seven different stands. The canopy cover was measured from two digital canopy photographic methods, including DHP (as the reference method) and DCP. The stand orthophotos were segmented using a multi-resolution image segmentation method. Afterward, the classification in two classes of the canopy cover and the non-canopy cover was conducted using minimum distance classification to estimate canopy cover. The CHM layer was generated based on the SfM algorithm and utilized in the canopy cover estimation in each stand as auxiliary data. The results showed a slight improvement when we used the CHM as auxiliary data. Overall, the results showed that the efficiency of the ground digital canopy photographic methods (zenith view) in multi-storied and dense forests is the lowest. In return, our method for digital aerial canopy photography (object-based canopy segmentation and classification) is simple, quick, efficient, and cost-effective.

Long-term estimation of the canopy photosynthesis of a leafy vegetable based on greenhouse climate conditions and nadir photographs

In horticultural crop production, accurately estimating the canopy photosynthetic rate (Ac) based on greenhouse climate conditions is of practical value for predicting and controlling crop growth and yield. We developed a method for continuously estimating Ac in a greenhouse from readily obtainable information (i.e., climatic data and canopy photographs) by combining a canopy photosynthesis model with image analysis. The canopy photosynthesis model was based on a sun/shade representation of the crop canopy combined with models of single-leaf photosynthesis, stomatal conductance, mass transfer and leaf energy balance. This combination allowed 1) the incorporation of all major climatic variables (i.e., radiation, CO2 concentration, air temperature, humidity, and wind velocity) into the Ac estimation and 2) the simultaneous estimation of Ac, canopy transpiration rate (Ec), and leaf temperature (TL). The leaf area index (Lc), which changes considerably throughout the growth period of a crop canopy, was evaluated nondestructively from the gap fractions of nadir digital photographs (i.e., the fractions of nonleaf area). The canopy photosynthesis model and image analysis results were combined and used to estimate the Ac, Ec, and TL of spinach canopies grown at ambient and elevated CO2 concentrations (c. 400 and 800 µmol mol−1, respectively). Regardless of the CO2 concentration, the estimates of Ac, Ec, and TL were in good agreement with measurements obtained with the open chamber method throughout the growth period. Analyzing the sensitivity of Ac to input variables revealed that the effects of climatic variables on Ac can vary considerably depending on the Lc and incoming radiation. The proposed method enables not only the estimation of Ac from readily obtainable information but also the quantitative evaluation of the effect of climate control on Ac in horticultural greenhouses.

Characterizing Canopy Openness in Open Forests: Spherical Densiometer and Canopy Photography Are Equivalent but Less Sensitive than Direct Measurements of Solar Radiation

AbstractIn forest ecosystems, canopy openness affects understory light availability, plant growth, and tree species recruitment, thus shaping future forest composition, structure, and functional diversity. Foresters must correctly and quickly measure canopy openness to meet their management objectives. To help guide the selection of an appropriate method for measuring canopy openness, we compared three common techniques that vary in cost, complexity, and time required for measurements and data processing: smartphone-based hemispherical photography, spherical densiometer measurements, and direct measurements of solar radiation (using AccuPAR ceptometer). We measured canopy openness using these three methods on 28 permanent forest health monitoring plots in pine-oak forests of the Central Pine Barrens of Long Island in New York State. By analysis of variance and regression analyses, we found the three methods (particularly densiometer and hemispherical photographs) yielded broadly equivalent and strongly positively correlated descriptions of canopy openness. The direct measurements of solar radiation seemed to have a greater potential to detect subtle variation in forest understory light. Forest managers may sufficiently characterize canopy openness using quick and cheap methods (e.g., spherical densiometers) and avoid larger costs of devices for direct light measurements (e.g., ceptometers) and the larger data-processing times of hemispherical photography.

Canopy dynamics in a tropical Atlantic forest mosaic in southeastern Brazil

The influence of seasonality on leaf production and canopy dynamics was evaluated in four areas in the Rio Doce State Park—RDSP, which is part of the Atlantic Forest Biosphere Reserve in Marlieria city, Minas Gerais State, southeastern Brazil. Leaf production was determined during a period of two years (2007 I and 2008 II) and on a monthly basis (25 collectors of 0.25 m2) to determine dry mass and specific leaf area at four different areas (Preta, Central, Garapa, and Anibal). Leaf area index of canopy values (LAI-canopy) was determined using hemispheric canopy photographs in October 2008 and March 2009. Specific leaf area of the leaf litter samples (LAI-SLA) was calculated during November (2008) and March (2009). Leaf production followed a seasonal rhythm, with higher cumulative production between the middle of the dry season and beginning of the rainy season (August to November). The LAI-canopy values did not have significant variations between the four areas evaluated; however, significant difference between seasons was observed in the Anibal and Central areas. The LAI-SLA was higher in Anibal while Preta, Central, and Garapa presented similar values. Our results evidenced the possible influence of the leaf fraction on canopy dynamics and LAI and revealed the rapid leaf renewal characteristics of seasonal semideciduous forests. We observed spatial heterogeneity of semideciduous forests maintaining a partial canopy cover even in the season with the greatest leaf fall. This explains to the absence of any significant correlation between leaf production and LAI-canopy as observed in the present study.

An overview of in situ digital canopy photography in forestry

Since the 1960s, canopy photography has been widely used in forestry. Hemispherical photography has been the most widely used technique, but a great drawback of this method is its perceived sensitivity to hemispherical image acquisition and processing. Over the last decade, several alternative photographic approaches using restricted view angle have been proposed. Cover photography acquired via a normal lens was the first of the recently introduced photographic techniques. Use of a restricted view (often fixed) lens has subsequently contributed to the extension of canopy photography to new sensors and platforms, which ultimately have provided answers to some previous challenges regarding within-crown clumping correction, isolated and urban tree measurements, understory assessment, operational leaf inclination angle measurements, and phenological monitoring. This study provides a comprehensive review of the use of canopy photography in forestry and describes the theory and definitions of the variables used to quantify canopy structure. A case study is presented to illustrate and compare the different features and performance of the existing overstory photographic techniques; the results make it possible to suggest sampling strategies for consistent overstory canopy photographic measurements. Emerging operational fields of canopy photography are also described and discussed.

Micropropagation of Mespilus germanica L.

The data presented in this paper is supporting the research article “Variable seed behavior increases recruitment success of a hardwood tree, Zelkova serrata, in spatially heterogeneous forest environments” (Oyama et al., 2018) [1]. We provided the data of several ecological properties of the two types of the seeds (i.e. shoot seeds vs. single seeds) with distinctly different dispersal behaviors. We provide data of terminal velocity, which was measured by releasing 50 replicates of each seed type from a height of 5.0 m in dead air space in a gymnasium. We also show the data of germination cue [i.e. red:far-red (R:FR) ratios], which was examined in plant growth chambers that received three distinct R:FR ratios (0.1, 0.4, and 1.0; 16 h photoperiod) or no illumination. Further, we show the data of the rates of multi-locus outcrossing rates and biparental inbreeding in each of single- and shoot seeds. The mating system parameters were estimated by assaying a total of 80 shoot seeds and 70 single seeds that were randomly collected from Parent 1 and Parent 2 for five microsatellite loci. Finally, we show the data of hemispherical canopy photographs, which were taken at different distance from the adults using a digital camera equipped with a fisheye lens.

Leaf area index in a forested mountain catchment

Leaf area index (LAI) belongs among the catchment characteristics widely used in hydrological models but still associated with great uncertainties. In a mountain forest catchment, the leaf area affects retention and evapotranspiration loss, and it could be significantly modified by forestry practices. In this study, LAI in mature stands of Norway spruce (Picea abies) and European beech (Fagus sylvatica) was analysed in headwater catchments of the Jizera Mountains (Czech Republic) between 2012 and 2016. A comparison evaluation of LAI in harvested site with dominant herbaceous vegetation was taken into account by applying direct ground investigation what was compared with hemispherical canopy photography (Gap light analyser GLA-V2) and satellite remote sensing (Sentinel-2 mission). While the direct ground measurement includes only the foliage (leaves or needles), the Gap light analysis is affected by trunks and branches, and the remote sensing techniques by herbaceous understory. The results of the Gap light analyser underestimated the ground based LAI values by 52–76 per cent, and satellite interpretations by 29–73 per cent. The remote sensing is capable to provide effective information on the distribution of LAI within the time and space. However, in a catchment scale, the satellite detection underestimated average LAI values approx. by 42–62 per cent. Changes in the observed rainfall interception reflected well the LAI variation.

Release of Suppressed Red Spruce Using Canopy Gap Creation—Ecological Restoration in the Central Appalachians

ABSTRACT: Red spruce (Picea rubens) and red spruce-northern hardwood mixed stands once covered as much as 300,000 ha in the Central Appalachians, but now comprise no more than 21,000 ha. Recently, interest in restoration of this forest type has increased because red spruce forests provide habitat for a number of rare animal species. Our study reports the results of an understory red spruce release experiment in hardwood-dominated stands that have a small component of understory red spruce. In 2005, 188 target spruce were identified in sample plots at six locations in central West Virginia. We projected a vertical cylinder above the crown of all target spruces, and in 2007, we performed a release treatment whereby overtopping hardwoods were treated with herbicide using a stem injection technique. Release treatments removed 0–10% (Control), 11–50% (Low), 51–89% (Medium), and ≤90% (High) of the basal area of overtopping trees. We also took canopy photographs at the time of each remeasurement in 2007, 2010, a...

Field test of canopy cover estimation by hemispherical photographs taken with a smartphone

AbstractAimTo test the Canopy Cover (CaCo) index for forest vegetation research estimation of canopy cover from hemispherical photographs, and introduce a new Android smartphone application for use of this index.MethodsThe original and modified CaCo index were evaluated using a data set of 234 hemispherical photographs taken in 78 plots in coniferous, mixed and broad‐leaved deciduous forests. The results of the CaCo analysis of these photographs were compared with expert field visual estimation of canopy cover of these plots. For each hemispherical photograph, several CaCo values were calculated based on the photograph being restricted to different degrees by artificial horizon masking. The CaCo index was also tested with respect to precision of canopy cover estimation and sensitivity to different photographic equipment, using a different set of 93 canopy photographs taken in mixed and coniferous forests. Calculation of the CaCo index was done with the newly developed GLAMA – Gap Light Analysis Mobile Application software.ResultsLinear regression showed a close relationship between the CaCo index and visually observed canopy cover data. A proposed calculation modification improved the stability of the CaCo index in cases in which no horizon masking was applied. The best fit, zero‐intercept and a regression slope close to1 were found in cases in which an artificial horizon mask that extended higher than 45° restricted the bottom part of the sky hemisphere. Low sensitivity of the CaCo index to type of photographic equipment used was shown.ConclusionsThe CaCo index is robust and can be used for precise canopy cover estimation, comparable to visual canopy cover estimation and unaffected by observer bias. Not only can it be used on already‐captured photographs, but the index can also be employed on smartphones to rapidly capture hemispherical photographs and immediately calculate their index values. This application is freely available on the Internet and can serve as a powerful research and educational tool that can not only calculate CaCo values, but also standardize forest canopy visual estimates.

Thermal canopy photography in forestry - an alternative to optical cover photography

Hemispherical canopy photography is a widely used technique to observe crown-related forest variables. However, standardization of this technique remains challenging, as exposure and threshold settings continue to constitute the main sources of variation of such photographs. This paper, therefore, presents a new method to overcome standardization issues by using thermal canopy photography. With a thermal camera, images are produced which are not critically limited in their dynamic range so that photographic exposure becomes irrelevant. Moreover, the high temperature contrast between “sky” and “non-sky”, resulting from extreme low sky temperatures, facilitates the unambiguous selection of a threshold which separates “sky” from “non-sky” pixels. For our comparison, we have taken canopy images with a high-resolution thermal camera (VarioCam hr head [Infratec, Dresden, Germany]) and an optical camera (Nikon D70s). The correlation of canopy closure values derived from the image pairs was r = 0.98. Our findings thus show that thermal canopy photography is a promising and simple to use alternative to optical canopy photography, because it limits possible sources of variability, since exposure settings and threshold definition cease to be an issue.

Digital canopy photography: Exposed and in the raw

Estimates of the canopy gap fraction, on which calculations of leaf area index (LAI) are based, are sensitive to photographic exposure in upward-facing images. In this article we describe a simple, automated method of image acquisition and processing that eliminates both subjectivity and the need for the operator to consider photographic exposure in the field. A key strength of our methodology was the use of a test apparatus (perforated aluminum screen) with a precisely known gap fraction; this allowed us to separate the confounding effects of gap size and gap fraction on the optimal photographic exposure for a canopy. We took photographs of the test apparatus at different photographic exposures; we varied the gap fraction by covering a proportion of the holes in the screen, and also varied gap size by varying the distance of the camera from the screen. We acquired both raw images and JPEG images. We found that the optimal exposure of JPEG images varied with both gap size and gap fraction, not just gap fraction as previously assumed. Underexposing by one stop yielded raw data that were never clipped resulting in data loss, but that used most of the 14-bit range of the raw file. We also found that it was easily possible to standardize photographic exposure during image processing by acquiring raw images in the field; thus eliminating the variation in estimated gap fraction and LAI associated with exposure variations. This result was replicated in both fisheye images and cover images that we acquired in real canopies. We recommend the following protocol for acquiring canopy images in future studies:1.Shoot raw using one stop of underexposure.2.Convert propriety-format raw files to DNG format using the free software Adobe DNG Converter.3.Contrast stretch the blue channel of the image and save as JPG for further analysis. The authors can supply MATLAB script to perform this step.

Pixel Color Clustering of Multi-Temporally Acquired Digital Photographs of a Rice Canopy by Luminosity-Normalization and Pseudo-Red-Green-Blue Color Imaging

Red-green-blue (RGB) channels of RGB digital photographs were loaded with luminosity-adjusted R, G, and completely white grayscale images, respectively (RGwhtB method), or R, G, and R + G (RGB yellow) grayscale images, respectively (RGrgbyB method), to adjust the brightness of the entire area of multi-temporally acquired color digital photographs of a rice canopy. From the RGwhtB or RGrgbyB pseudocolor image, cyan, magenta, CMYK yellow, black, L*, a*, and b* grayscale images were prepared. Using these grayscale images and R, G, and RGB yellow grayscale images, the luminosity-adjusted pixels of the canopy photographs were statistically clustered. With the RGrgbyB and the RGwhtB methods, seven and five major color clusters were given, respectively. The RGrgbyB method showed clear differences among three rice growth stages, and the vegetative stage was further divided into two substages. The RGwhtB method could not clearly discriminate between the second vegetative and midseason stages. The relative advantages of the RGrgbyB method were attributed to the R, G, B, magenta, yellow, L*, and a* grayscale images that contained richer information to show the colorimetrical differences among objects than those of the RGwhtB method. The comparison of rice canopy colors at different time points was enabled by the pseudocolor imaging method.

EFFECT OF CANOPY GAPS A'ND TOPOGRAPHIC REGIMES IN SEEDLINGS PERFORMANCE IN SINHARAJA RAIN FOREST, SOUTHWEST SFU LANKA

Growth and survival of tree canopy dominant seedlings in the Sinharaja lowland rain forest insouthwest Sri Lanka were monitored. Twelve canopy gaps and closed canopy sites wereselected, as four of each on different topographic positions- valley, midslope and ridgetop.Measurements of height, number of leaves and mortality were recorded over a two-year period.Hemispherical canopy photographs were taken to calculate Indirect Site Factor (ISF), Direct SiteFactor (DSF), and canopy openness. Greatest canopy openness, highest DSF values wererecorded for ridgetop sites and smallest values were recorded for valley sites. Over the two-yearperiod sixty-six (11.45%) seedlings died in the ridge top, which indicated the highest mortalityrate. Survival of seedlings in the canopy gap ani .orest understorey declined on progressingfrom valley to ridgetop sites. Seedlings of Mesua ferrea had a higher survival than other speciesin the canopy opening and understorey conditions. Height growth and leaf number were greatestin the gap sites. A significant relationship was found between DSF and maximum height growth(33.05,P>O.OO) for Syzygium rubicundum. Shorea trapezlfolta, Shorea distich a and Syzygiumrubicundum showed greatest height increment .n the valley, midslope and ridgetop sitesrespectively. No relationship was found between DSF and leaf numbers in all seedlings exceptSyzygium rubicundum, where has increased with increasing DSF.

Solarcalc 7.0: An enhanced version of a program for the analysis of hemispherical canopy photographs

This paper describes solarcalc 7.0, a new implementation of a computer program designed for the analysis of hemispherical photographs. Our aim was to recode, optimize, enhance and recompile the previous version of solarcalc program using Realbasic, a modern, cross-platform BASIC language programming environment. The main improvements of the new version are described as follows: Programming and layout – a revision and enhancement of the original source code in a new, redesigned and user-friendly interface; Calculations – the possibility of allowing calculations for a growing season length, the possibility of defining the number of zenith and azimuth angles used for the calculations, the calculations of direct, indirect and total site factors, the inclusion of two versions of the Standard Overcast (SOC) sky weighting formula, the ability to compute leaf area index using two different methods and to compute the sky view factor, the ability to compute the total daily extraterrestrial radiation, the capacity of handling grayscale and color images and to manually or automatically threshold the images. The performance of the new version of solarcalc was assessed using a series of hemispherical images taken along a light gradient. Comparisons of calculated canopy light and structural indices between the new version of the program and gla (Gap Light Analyser) show highly significant positive correlations (R2=1.00), indicating that solarcalc performs similarly to gla across a variety of forest canopy openings. The incorporated modifications in the new version of the program allows for more detailed and more versatile analyses of hemispherical photographs and as such, represent a significant improvement in comparison with the previous version of the program. Finally, one of the most salient feature of solarcalc compared to other similar software is the possibility of using compiled versions of the program compatible with Macintosh, Windows and Linux/Unix operating systems, localised in English, French and Spanish languages.

EFFECT OF SHADING ON SURViVAL AND GROWTH OF Mesua (CLUSIACEAE) AND Shorea (DIPTEOCARPACEAE) SEEDLINGS ACROSSTOPOGRAPHIC GRADIENT IN SINHARAJA RAIN FOREST, SOUTHWEST SRI lANKA

The effect of shading on survival and growth of two species of Mesua (Clusiaceae) andfour species of Shorea (Dipteocarpaceaeh planted seedlings were investigated at differenttopographic positions in Sinharaja rain forest All occur together as canopy dominant treesIII Sinharaja rain forest Twelve-understory sites were selected, four each on differenttopographic posilions valley, midslope and ridgetop. Measurements of height, number ofleaves, root collar diameter and the mortality were recorded over a five-year period.Hemispherical canopy photographs were taken to calculate Indirect Site Factor (ISF),Direct Site Factor (DSF), and the Leaf Area Index (LAI). Analysis of photographsdemonstrated that LAI decreased from valley to ridge top while DSF and ISF increasedfrom the valley to ridge top. After five years thirty-four (34 %) seedlings died in the ridgelop and the lowest mortality was recorded in the midslope. Seedlings of Mesua ferrea L.had the highest survival than other species in all understory conditions and the lowestsurvival rate recorded for Shorea trapezifolia (Thw.) Ashton. Results showed cleardifferences in survival and growth among species. These differences appeared related (0availability of soil moisture and understory radiation regimes.

Database of Masaryk University's Vegetation Research in Siberia

The Database of Masaryk University's Vegetation Research in Siberia (GIVD ID 00-RU-002) contains records from 100-m2 vegetation plots collected since 2003 during reasearch expeditions of Masaryk University in Siberia and Bashkortostan, namely in the Southern Urals, Altai and Western Sayan Mountains, and Central Yakutia. Most plots were recorded in forest, steppe and alpine tundra vegetation. Each plot contains a full record of vascular plants, terricolous bryophytes and macrolichens, supplemented with measurements of soil properties and hemispheric canopy photographs. Subsets of plots contain records of modern pollen deposition, molluscan community composition and herbaceous biomass. The database is used for biodiversity studies with reference to palaeoecology and modern vegetation-environment relationships.

Concentrated Distribution of Wild Yam Patches: Historical Ecology and the Subsistence of African Rainforest Hunter-Gatherers

Availability of annually reproducing wild yam species (Dioscorea praehensilis and Dioscorea semperflorens) is considered to be a key factor for the viability of forest hunter-gatherer subsistence in the African rainforests. I here describe the habitat and distribution of wild yam patches, and discuss possible human impacts on the formation of wild yam patches, which currently support long-term forest expeditions by Baka hunter-gatherers in southeastern Cameroon. An analysis of canopy photographs shows that annual yams favor a habitat of canopy gaps which receive sufficient sunlight. However, the fact that annual yams patches are limited to specific locations even though gaps in the canopy occur throughout the forest, combined with the mostly vegetative reproductive system of the yams, suggests annual yams do not propagate extensively in the wild. Moreover, areas with abundant annual yam patches that are presently situated far from any villages contain several abandoned village sites. Since the Baka often transplant parts of yam tubers to encourage their spread, it seems that human activities may have contributed to the formation of locally concentrated annual yam patches.

Acclimation of maximum quantum yield of PSII and photosynthetic pigments of Panax quinquefolius L. to understory light

Forest-grown American ginseng (Panax quinquefolius L.) is exposed to daily and seasonal light variations. Our goal was to determine the effect of understory light changes on the maximum quantum yield of photosystem II, expressed as <TEX>$F_v/F_m$</TEX>, and photosynthetic pigment composition of two-year-old plants. Understory light photon flux density and sunfleck durations were characterized using hemispherical canopy photography. Our results showed that understory light significantly affected the <TEX>$F_v/F_m$</TEX> of American ginseng, especially during the initial development of the plants when light levels were the highest, averaging 28 mol <TEX>$m^{-2}d^{-1}$</TEX>. Associated with low <TEX>$F_v/F_m$</TEX> during its initial development, American ginseng had the lowest levels of epoxidation state of the xanthophyll cycle of the season, suggesting an active dissipation of excess light energy absorbed by the chlorophyll pigments. As photon flux density decreased after the deployment of the forest canopy to less than 10 mol <TEX>$m^{-2}d^{-1}$</TEX>, chlorophyll a/b decreased suggesting a greater investment in light harvesting pigments to reaction centers in order to absorb the fleeting light energy.

Evaluation of irradiance metrics with respect to predicting sapling growth

Accurate and efficient measurement of photosynthetically active radiation (PAR) is critical in ecological studies. We evaluated 25 metrics of PAR with respect to predicting growth of sugar maple ( Acer saccharum Marsh.) and white ash ( Fraxinus americana L.) saplings from understory to large gap conditions. PAR metrics were derived from gallium arsenide photodiodes, hemispherical canopy photographs (film and digital), and a LI-COR LAI-2000 plant canopy analyzer. In general, percent canopy openness, estimated with film photographs or LAI-2000, best predicted growth. Mean daily photosynthetic photon flux density (PPFD) from photodiodes ranked intermediate; direct beam radiation (from digital and film photographs) was among the poorest growth predictors. Metrics that integrate direct radiation may be relatively poor predictors of growth, because sunflecks were above PPFD levels at which photosynthesis saturates but fully contributed to the calculation of mean daily PPFD. Mean daily PPFD based on truncated sunflecks (to PPFD levels at which photosynthesis saturates) improved predictions of white ash radial growth. Film canopy photographs and the LAI-2000 had relatively low measurement error (indicated by repeatability). High contrast in film photographs, compared to digital, reduced ambiguity in manual thresholding. From a plant-centered perspective, percent canopy openness measured with either the LAI-2000 or film hemispherical photographs provided the best growth predictions.

Cultivation of Non‐timber Forest Products Alters Understory Light Availability in a Humid Tropical Forest in Mexico1

ABSTRACTThe planting of non‐timber forest products (NTFPs) in the understory of tropical forests is promoted in many regions as a strategy to conserve forested lands and meet the economic needs of rural communities. While the forest canopy is left intact in most understory plantations, much of the midstory and understory vegetation is removed in order to increase light availability for cultivated species. We assessed the extent to which the removal of vegetation in understory plantations of Chamaedorea hooperiana Hodel (Arecaceae) alters understory light conditions. We also examined how any changes in light availability may be reflected by changes in the composition of canopy tree seedlings regenerating in understory plantations. We employed a blocked design consisting of four C. hooperiana plantation sites; each site was paired with an adjacent, unmanaged forest site. Hemispherical canopy photographs were taken and canopy tree seedlings were identified and measured within 12 3 × 2 m randomly placed plots in each site for a total of 96 plots (4 blocks × 2 sites × 12 plots). Plantation management did not affect canopy openness or direct light availability but understory plantations had a higher frequency of plots with greater total and diffuse light availability than unmanaged forest. Comparisons of canopy tree seedling composition between understory plantations and unmanaged forest sites were less conclusive but suggest that management practices have the potential to increase the proportion of shade‐intolerant species of tree seedlings establishing in plantations. Given the importance of advanced regeneration in gap‐phase forest dynamics, these changes may have implications for future patterns of succession in the areas of forest where NTFPs are cultivated.