Journal articles on the topic 'Canopy density'
To see the other types of publications on this topic, follow the link: Canopy density.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Canopy density.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Azadeh, Abdollahnejad, Panagiotidis Dimitrios, and Surový Peter. "Forest canopy density assessment using different approaches – Review." Journal of Forest Science 63, No. 3 (March 28, 2017): 107–16. http://dx.doi.org/10.17221/110/2016-jfs.
Full textAbstract:
Crown canopy is a significant regulator of forest, affecting microclimate, soil conditions and having an undeniable role in a forest ecosystem. Among the different materials and approaches that have been used for the estimation of crown canopy, satellite based methods are among the most successful methods regarding cost-saving efforts and different kinds of options for measuring the crown canopy. Different types of satellite sensors can result in different outputs due to their various spectral and spatial resolution, even when using the same methodologies. The aim of this review is to assess different remote sensing methods for forest crown canopy density assessment.
2
Levy, Amit, Taylor Livingston, Chunxia Wang, Diann Achor, and Tripti Vashisth. "Canopy Density, but Not Bacterial Titers, Predicts Fruit Yield in Huanglongbing-Affected Sweet Orange Trees." Plants 12, no. 2 (January 7, 2023): 290. http://dx.doi.org/10.3390/plants12020290.
Full textAbstract:
In Florida, almost all citrus trees are affected with Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas). We characterized various parameters of HLB-affected sweet orange trees in response to yield-improving nutritional treatment, including canopy volume, canopy density and CLas Ct values, and found that the treatment improved yield and maintained canopy density for over three years, whereas untreated HLB-affected trees declined in canopy density. The nutritional treatment did not affect CLas titer or the tree canopy volume suggesting that canopy density is a better indicator of fruit yield. To further validate the importance of canopy density, we evaluated three independent orchards (different in tree age or variety) to identify the specific traits that are correlated with fruit yields. We found that canopy density and fruit detachment force (FDF), were positively correlated with fruit yields in independent trials. Canopy density accurately distinguished between mild and severe trees in three field trials. High and low producing HLB trees had the same Ct values. Ct values did not always agree with CLas number in the phloem, as visualized by transmission electron microscopy. Our work identifies canopy density as an efficient trait to predict yields of HLB-affected trees and suggests canopy health is more relevant for yields than the CLas population.
3
Ashaari, Faisal, Muhammad Kamal, and Dede Dirgahayu. "COMPARISON OF MODEL ACCURACY IN TREE CANOPY DENSITY ESTIMATION USING SINGLE BAND, VEGETATION INDICES AND FOREST CANOPY DENSITY (FCD) BASED ON LANDSAT-8 IMAGERY (CASE STUDY: PEAT SWAMP FOREST IN RIAU PROVINCE)." International Journal of Remote Sensing and Earth Sciences (IJReSES) 15, no. 1 (July 6, 2018): 81. http://dx.doi.org/10.30536/j.ijreses.2018.v15.a2845.
Full textAbstract:
Identification of a tree canopy density information may use remote sensing data such as Landsat-8 imagery. Remote sensing technology such as digital image processing methods could be used to estimate the tree canopy density. The purpose of this research was to compare the results of accuracy of each method for estimating the tree canopy density and determine the best method for mapping the tree canopy density at the site of research. The methods used in the estimation of the tree canopy density are Single band (green, red, and near-infrared band), vegetation indices (NDVI, SAVI, and MSARVI), and Forest Canopy Density (FCD) model. The test results showed that the accuracy of each method: green 73.66%, red 75.63%, near-infrared 75.26%, NDVI 79.42%, SAVI 82.01%, MSARVI 82.65%, and FCD model 81.27%. Comparison of the accuracy results from the seventh methods indicated that MSARVI is the best method to estimate tree canopy density based on Landsat-8 at the site of research. Estimation tree canopy density with MSARVI method showed that the canopy density at the site of research predominantly 60-70% which spread evenly.
4
Paudel, Achyut, Manoj Karkee, Joseph R. Davidson, and Cindy Grimm. "Canopy Density Estimation of Apple Trees." IFAC-PapersOnLine 55, no. 32 (2022): 124–28. http://dx.doi.org/10.1016/j.ifacol.2022.11.126.
Full text
5
Ou, Mingxiong, Tianhang Hu, Mingshuo Hu, Shuai Yang, Weidong Jia, Ming Wang, Li Jiang, Xiaowen Wang, and Xiang Dong. "Experiment of Canopy Leaf Area Density Estimation Method Based on Ultrasonic Echo Signal." Agriculture 12, no. 10 (September 28, 2022): 1569. http://dx.doi.org/10.3390/agriculture12101569.
Full textAbstract:
Variable-rate spray systems with canopy leaf area density information detection are an important approach to reducing pesticide usage in orchard management. In order to estimate the canopy leaf area density using ultrasonic sensors, this article proposed three parameter model equations based on ultrasonic echo peaks for canopy leaf area density estimation and verified the accuracy of the three parameter model equations using laboratory-simulated canopy and outdoor tree experiments. The orthogonal regression statistics results from the laboratory-simulated canopy experiment indicated that parameter Vc is more suitable for canopy leaf area density estimation compared to parameter Va and Vb when the density ranges from 0.54 to 5.4 m2m−3. The model equation from parameter Vc has minor systematic errors, and the predicted and observed values of parameter Vc have good agreement with the experimental conditions. The laboratory-simulated canopy and outdoor tree canopy leaf area density verification experiments of parameter Vc were carried out, and the results indicated that the absolute value of the mean relative error is 5.37% in the laboratory-simulated canopy and 2.84% in outdoor tree experiments. The maximum absolute value of the relative error is 8.61% in the laboratory-simulated canopy and 14.71% in the outdoor tree experiments, and the minimum absolute value of the relative error is 3.21% in the laboratory-simulated canopy and 0.56% in the outdoor tree experiments. The laboratory-simulated canopy leaf area density verification results showed that the mean relative errors under canopy leaf area density 0.98 and 4.92 m2m−3 conditions are 6.29% and 5.82%, respectively, which is larger than the mean relative error under 2.95 m2m−3; nevertheless, these results proved that this model equation is applicable for canopy information detection and advanced pesticide application development in future.
6
Andreu, Anne G., John I. Blake, and Stanley J. Zarnoch. "Estimating canopy fuel characteristics for predicting crown fire potential in common forest types of the Atlantic Coastal Plain, USA." International Journal of Wildland Fire 27, no. 11 (2018): 742. http://dx.doi.org/10.1071/wf18025.
Full textAbstract:
We computed four stand-level canopy stratum variables important for crown fire modelling – canopy cover, stand height, canopy base height and canopy bulk density – from forest inventory data. We modelled the relationship between the canopy variables and a set of common inventory parameters – site index, stem density, basal area, stand age or stand height – and number of prescribed burns. We used a logistic model to estimate canopy cover, a linear model to estimate the other canopy variables, and the information theoretic approach for model selection. Coefficients of determination across five forest groups were 0.72–0.91 for stand height, 0.36–0.83 for canopy base height, 0.39–0.80 for canopy cover, and 0.63–0.78 for canopy bulk density. We assessed crown fire potential (1) for several sets of environmental conditions in all seasons, and (2) with increasing age, density and number of prescribed burns using our modelled canopy bulk density and canopy base height variables and local weather data to populate the Crown Fire Initiation and Spread model. Results indicated that passive crown fire is possible in any season in Atlantic coastal plain pine stands with heavy surface fuel loads and active crown fire is most probable in infrequently burned, dense stands at low fuel moistures.
7
Saito, Waka, Koji Kawamura, and Hiroshi Takeda. "Relative importance of overstory canopy openness and seedling density on crown morphology and growth of Acer nipponicum seedlings." Botany 90, no. 11 (November 2012): 1152–60. http://dx.doi.org/10.1139/b2012-079.
Full textAbstract:
We investigated the effects of overstory canopy openness and seedling density on seedling morphology and growth in the mid-successional species Acer nipponicum Hara in a cool-temperate forest. Studied seedlings were 46 seedlings of 30–160 cm height, and their overstory canopy openness ranged between 7.2% and 17.0%. Seedling density, measured as the number of conspecific neighboring seedlings within a 50 cm radius of the target seedling, ranged between 0 and 19. There were no significant correlations between seedling height, canopy openness, and seedling density. Multiple regression analysis showed that crown depth, leaf mass fraction, and leaf area index decreased with decreasing canopy openness and increasing seedling density, while the ratio of trunk-lateral branches mass increased. Overstory canopy openness did not affect crown area, leaf size, or petiole length, all of which decreased with increasing seedling density. Standardized regression coefficients indicated that seedling density affected morphology and growth more than canopy openness did. The morphological responses to canopy openness cannot be considered as adaptive plasticity, as total leaf area and leaf mass fraction decreased with decreasing light levels. In contrast, responses to seedling density indicate adaptive responses to neighborhood competition. The results highlight the importance of seedling density that influenced seedling growth and morphology independently of overstory canopy openness.
8
Umarhadi, Deha Agus, and Akbar Muammar. "Regression model accuracy comparison on mangrove canopy density mapping." Digital Press Physical Sciences and Engineering 1 (2018): 00001. http://dx.doi.org/10.29037/digitalpress.11249.
Full textAbstract:
<p class="Abstract">Mangrove canopy density condition is often considered in the coastal environment management, so that the accurate data of spatial distribution of mangrove canopy density is needed. This condition need to be studied further related to methods in the mangrove canopy density mapping. However, did not much research compare the mapping accuracy about mangrove canopy density using vegetation index and the combination of statistical regression models, especially using Sentinel-2A satellite imagery. The purpose of this study is to compare the accuracy of mangrove canopy density mapping using NDVI, MSAVI, and MSARVI with simple linear, quadratic, logarithmic, and exponential regression applied to Sentinel-2A satellite imagery. Mangrove canopy density data resulted from a field survey at Jor and Kecebing Bay, East Lombok. The result of accuracy analysis presented NDVI was the best vegetation index in mapping compared MSAVI and MSARVI with an accuracy above 80 % (linear regression analysis of NDVI: 81.66 %, quadratic regression analysis of NDVI: 80.84 %, exponential regression analysis of NDVI: 80.71 %, logarithmic regression analysis of NDVI: 80.68 %). Mapping the mangrove canopy density through the combination of another vegetation index (MSAVI and MSARVI) with four regression models had accuracy of between 70 % to 80 %, except a mangrove canopy density mapping accuracy using quadratic regression between MSARVI and field data, only reached 62.78 %. <o:p></o:p></p>
9
Flukes, EB, CR Johnson, and JT Wright. "Thinning of kelp canopy modifies understory assemblages: the importance of canopy density." Marine Ecology Progress Series 514 (November 6, 2014): 57–70. http://dx.doi.org/10.3354/meps10964.
Full text
10
Sembiring, S. S. B., R. Hermawan, and S. B. Rushayati. "The concentration of CO2 on two canopy densities in Taman Kota 1 Bumi Serpong Damai, South Tangerang." IOP Conference Series: Earth and Environmental Science 918, no. 1 (November 1, 2021): 012008. http://dx.doi.org/10.1088/1755-1315/918/1/012008.
Full textAbstract:
Abstract Global warming occurs because many greenhouse gases (GHG) retain heat from the earth, which causes the earth’s surface temperature to increase. The GHG contributing most to global warming is carbon dioxide (CO2) due to its highest atmosphere concentration and long life span. The increasing CO2 concentrations in urban areas are caused by transportation and industrial activities. City parks with high tree densities are the potential to reduce CO2 concentration. However, studies related to tree canopy density in reducing CO2 concentrations have not been widely carried out. This study aims to determine the CO2 concentration on two different canopy densities. This research was conducted in March - April 2021 in Taman Kota 1 BSD. Primary data collection was carried out by three replicates based on time as follows: 06.00 am, 01.00 pm, and 05.00 pm at low canopy density and high canopy density locations, respectively, by using the AZ 7725 Carbon dioxide meter tool. The low canopy density had a leaf area index (LAI) of 1.039, whereas the high canopy density had an LAI of 1.409. The highest CO2 concentration is 582.43 ppm in the high canopy density in the morning, while the lowest is 463.16 ppm occurred at the low canopy density in the afternoon. In the morning, CO2 from respiration is still concentrated under the dense canopy because there is less wind to disperse. In the afternoon, the wind speed is higher so that CO2 is more easily distributed.
11
Arya*, Neeta, and Jeet Ram. "Influence of canopy cover on vegetation in P. roxburghii sarg (chir-pine) dominated forests in Uttarakhand Himalaya, India." International Journal of Bioassays 5, no. 06 (May 31, 2016): 4617. http://dx.doi.org/10.21746/ijbio.2016.06.006.
Full textAbstract:
Increasing anthropogenic pressure and dependence on plant products have led to widespread exploitation of natural forests in the Uttaranchal Himalaya. The present study was carried out to study the influence of canopy cover on tree, shrub and herb vegetation. For this three different canopy types, open canopy (<30%, cover), moderate canopy (30-60%, cover) and close canopy (>60%, cover) were identified in Pinus roxburghii (chir-pine) dominated forests. The study area is located between 290 20’and 290 30’ N latitude and 790 23’ and 790 42’ E longitude between 1350-2000m elevations in Uttarakhand a newly created hill state. Total tree density was high in close canopy sites basal area was greater in open canopy sites. Total shrub density varied from 26107 to 28560 shrub/ha. It was maximum for open canopy sites and minimum for moderate canopy sites. Total shrubs cover varied from 45.8 to 50.6%. Shrubs cover was maximum for moderate canopy sites and minimum for open canopy sites. Herbs density was greater in open canopy and total herbs cover was greater in close canopy. Tree and shrub diversity was high in close canopy sites and herbs diversity in open canopy sites.
12
Keane, Robert E., Elizabeth D. Reinhardt, Joe Scott, Kathy Gray, and James Reardon. "Estimating forest canopy bulk density using six indirect methods." Canadian Journal of Forest Research 35, no. 3 (March 1, 2005): 724–39. http://dx.doi.org/10.1139/x04-213.
Full textAbstract:
Canopy bulk density (CBD) is an important crown characteristic needed to predict crown fire spread, yet it is difficult to measure in the field. Presented here is a comprehensive research effort to evaluate six indirect sampling techniques for estimating CBD. As reference data, detailed crown fuel biomass measurements were taken on each tree within fixed-area plots located in five important conifers types in the western United States, using destructive sampling following a series of four sampling stages to measure the vertical and horizontal distribution of canopy biomass. The six ground-based indirect measurement techniques used these instruments: LI-COR LAI-2000, AccuPAR ceptometer, CID digital plant canopy imager, hemispherical photography, spherical densiometer, and point sampling. These techniques were compared with four aggregations of crown biomass to compute CBD: foliage only, foliage and small branchwood, foliage and all branchwood (no stems), and all canopy biomass components. Most techniques had the best performance when all canopy biomass components except stems were used. Performance dropped only slightly when the foliage and small branchwood canopy biomass aggregation (best approximates fuels available for crown fires) was employed. The LAI-2000, hemispherical photography, and CID plant canopy imager performed best. Regression equations that predict CBD from gap fraction are presented for all six techniques.
13
Engelstad, Peder S., Michael Falkowski, Peter Wolter, Aaron Poznanovic, and Patty Johnson. "Estimating Canopy Fuel Attributes from Low-Density LiDAR." Fire 2, no. 3 (June 28, 2019): 38. http://dx.doi.org/10.3390/fire2030038.
Full textAbstract:
Simulations of wildland fire risk are dependent on the accuracy and relevance of spatial data inputs describing drivers of wildland fire, including canopy fuels. Spatial data are freely available at national and regional levels. However, the spatial resolution and accuracy of these types of products often are insufficient for modeling local conditions. Fortunately, active remote sensing techniques can produce accurate, high-resolution estimates of forest structure. Here, low-density LiDAR and field-based data were combined using randomForest k-nearest neighbor imputation (RF-kNN) to estimate canopy bulk density, canopy base height, and stand age across the Boundary Waters Canoe Area in Minnesota, USA. RF-kNN models produced strong relationships between estimated canopy fuel attributes and field-based data for stand age (Adj. R2 = 0.81, RMSE = 10.12 years), crown fuel base height (Adj. R2 = 0.78, RMSE = 1.10 m), live crown base height (Adj. R2 = 0.7, RMSE = 1.60 m), and canopy bulk density (Adj. R2 = 0.48, RMSE = 0.09kg/m3). These results suggest that low-density LiDAR can help estimate canopy fuel attributes in mixed forests, with robust model accuracies and high spatial resolutions compared to currently utilized fire behavior model inputs. Model map outputs provide a cost-efficient alternative for data required to simulate fire behavior and support local management.
14
Brygadyrenko, Viktor V. "Effect of canopy density on litter invertebrate community structure in pine forests." Ekológia (Bratislava) 35, no. 1 (March 1, 2016): 90–102. http://dx.doi.org/10.1515/eko-2016-0007.
Full textAbstract:
Abstract We investigated the structure of the litter invertebrate community in 141 pine (Pinus sylvestris Linnaeus, 1753) forest sites with five variants of canopy density (30-44, 45-59, 60-74, 75-89 and 90-100%) in the steppe zone of Ukraine. The total number of litter macrofauna specimens collected at each site decreased from an average of 84/100 trap-days in the sparsest stands (30-40% density) to 4-39 specimens/100 trap-days in the forests with a denser canopy. The number of macrofauna species caught in the pitfall traps does not vary significantly with different degrees of canopy density. The Shannon-Weaver and Pielou diversity indexes show increases corresponding to increasing stages of canopy density. The average share of phytophages in the trophic structure of the litter macrofauna does not vary with canopy density. The relative number of saprophages decreases from 54% in the forests with the sparsest canopy to 11-13% in the forests with denser canopies. The relative number of saprophages in pine forests (22%) is lower than that in deciduous forests (40%). The share of zoophages in the trophic structure of the litter macrofauna increases significantly with the increase in the pine forest canopy density (from 21% in the sparsest plots to 59% in the densest). The relative number of polyphages is highest (47-65%) when the canopy density is 45-89%. At canopy densities below or above this range, the share of polyphages in the community decreases to 20 and 24%, respectively. Regardless of canopy density, Formicidae and Lycosidae invariably rank amongst the first three dominant families. Nine families of invertebrates dominate in the pine forest stands with the highest density (90-100%), and 5-7 families dominate in the stands with lower density. For the pine forest litter macrofauna, we have observed an extreme simplification of the community size structure compared with natural and planted deciduous forests of the steppe zone of Ukraine.
15
Tombesi, S., and D. Farinelli. "Canopy management in super high-density olive orchards: relationship between canopy light penetration, canopy size and productivity." Acta Horticulturae, no. 1177 (November 2017): 87–92. http://dx.doi.org/10.17660/actahortic.2017.1177.9.
Full text
16
Danková, Lucia, and M. Saniga. "Canopy gaps and tree regeneration patterns in multi-species unmanaged natural forest Sitno (preliminary results)." Beskydy 6, no. 1 (2013): 17–26. http://dx.doi.org/10.11118/beskyd201306010017.
Full textAbstract:
The study of canopy gaps structure and tree regeneration patterns was conducted in mixed old-growth forest Sitno. We asked the following questions: What is the spatial scale of disturbance events? How does gap size affect the density of tree seedlings and saplings? Are there any differences in species composition of seedlings and saplings between the closed canopy and expanded gap? The research was conducted on a 2.5-ha (250 × 100 m) research plot. In total, 25 canopy openings were recorded. Canopy gaps and expanded gaps covered 22.8 % and 59.5 % of the research area. The most frequent were canopy gaps with the size up to 300 m2(64 %). Regarding the number of gapmakers, we recorded a quite large variability with the highest frequency of the gaps with 1 and 4 gapmakers. Regeneration structure (density and frequency) was sampled in 3.14 m2circular plot (n = 216) established on the grid intersections (10 × 10 m). A total of 8 tree species were identified in natural regeneration. The difference between overall density of natural regeneration under closed canopy and in expanded gaps was observed. The density of all tree species seedlings (except ofCarpinus betulus) was higher under closed canopy than in expanded gaps. The most frequent were seedlings ofAcer pseudoplatanusandAcer platanoideswhich occurred on 80 % and 73 % of the plots under closed canopy, and 75 % and 68 % of the plots in expanded gaps. Seedlings ofQuercus petraeawere not recorded. Density of saplings was higher in expanded gaps than under canopy (except of saplings ofAcer platanoidesandTilia cordata). The density of saplings ofAcer pseudoplatanusandAcer platanoidesincreased with increasing size of expanded gap, whileFraxinus excelsiorsaplings density decreased. There was no significant relationship between density of other species seedlings and saplings and expanded gap size.
17
Nandy, S., P. K. Joshi, and K. K. Das. "Forest canopy density stratification using biophysical modeling." Journal of the Indian Society of Remote Sensing 31, no. 4 (December 2003): 291–97. http://dx.doi.org/10.1007/bf03007349.
Full text
18
Sulistiyono, N., R. Syafitri, and S. A. Hudjimartsu. "Application of sentinel 2A sattelite imagery for the estimation of canopy cover spatial distribution at mangrove vegetation." IOP Conference Series: Earth and Environmental Science 977, no. 1 (June 1, 2022): 012092. http://dx.doi.org/10.1088/1755-1315/977/1/012092.
Full textAbstract:
Abstract Mangrove canopy density is one of the important variables for monitoring the health of mangrove vegetation. The vegetation index in satellite imagery is one of the variables that can be used to estimate the distribution of mangrove forest canopy cover. This study aims to predict the distribution of canopy cover of mangrove planted in Lubuk Kertang. The method used is regression analysis by connecting the NDVI value in the Sentinel 2A satellite image with the canopy density value in the field. Measurement of canopy cover in the field using a fisheye camera. The use of GIS is used to determine the spatial distribution of canopy cover. This study indicates that the linear regression model can estimate the canopy density distribution of mangrove vegetation in Lubuk Kertang with an R square value of 53.6% (sig < 0.005).
19
Eensalu, Eve, Priit Kupper, Arne Sellin, Märt Rahi, Anu Sõber, and Olevi Kull. "Do stomata operate at the same relative opening range along a canopy profile of Betula pendula?" Functional Plant Biology 35, no. 2 (2008): 103. http://dx.doi.org/10.1071/fp07258.
Full textAbstract:
Stomatal density and size were measured along the light gradient of a Betula pendula Roth. canopy in relation to microclimatic conditions. The theoretical stomatal conductance was calculated using stomatal density and dimensions to predict to what degree stomatal conductance is related to anatomical properties and relative stomatal opening. Stomatal density was higher and leaf area smaller in the upper canopy, whereas epidermal cell density did not change significantly along the canopy light gradient, indicating that stomatal initiation is responsible for differences in stomatal density. Stomatal dimensions – the length of guard cell on the dorsal side and the guard cell width – decreased with declining light availability. Maximum measured stomatal conductance and modelled stomatal conductance were higher at the top of the crown. The stomata operate closer to their maximum openness and stomatal morphology is a more important determinant of stomatal conductance in the top leaves than in leaves of lower canopy. As stomata usually limit photosynthesis more in upper than in lower canopy, it was concluded that stomatal morphology can principally be important for photosynthesis limitation in upper canopy.
20
Weiser, Michael D., Nathan J. Sanders, Donat Agosti, Alan N. Andersen, Aaron M. Ellison, Brian L. Fisher, Heloise Gibb, et al. "Canopy and litter ant assemblages share similar climate–species density relationships." Biology Letters 6, no. 6 (May 12, 2010): 769–72. http://dx.doi.org/10.1098/rsbl.2010.0151.
Full textAbstract:
Tropical forest canopies house most of the globe's diversity, yet little is known about global patterns and drivers of canopy diversity. Here, we present models of ant species density, using climate, abundance and habitat (i.e. canopy versus litter) as predictors. Ant species density is positively associated with temperature and precipitation, and negatively (or non-significantly) associated with two metrics of seasonality, precipitation seasonality and temperature range. Ant species density was significantly higher in canopy samples, but this difference disappeared once abundance was considered. Thus, apparent differences in species density between canopy and litter samples are probably owing to differences in abundance–diversity relationships, and not differences in climate–diversity relationships. Thus, it appears that canopy and litter ant assemblages share a common abundance–diversity relationship influenced by similar but not identical climatic drivers.
21
Teti, Patrick. "Relations between peak snow accumulation and canopy density." Forestry Chronicle 79, no. 2 (April 1, 2003): 307–12. http://dx.doi.org/10.5558/tfc79307-2.
Full textAbstract:
Snow was monitored for five years in plots from which 30% of the timber had been previously removed in the form of group selection and in an unlogged control at a sub-alpine site in British Columbia. Average peak snow water equivalents (SWE) ranged from 38 to 52 cm and occurred between late March and mid-April. Canopy density was measured in circular areas of sky in 10-degree increments from the zenith to the horizon. The optimum parameter for explaining the variability of peak SWE was canopy density within a 60- to 80-degree-wide cone. Results suggest that where openings are 1 ha or less, peak SWE approached a locally consistent maximum value when canopy density approached zero. This improves our ability to predict the effects of group selection on snow accumulation in high elevation forests. Key words: forest canopy, snow interception, snow accumulation, group selection
22
Pratama, I. Gede Merta Yoga, I. Wayan Gede Astawa Karang, and Yulianto Suteja. "Distribusi Spasial Kerapatan Mangrove Menggunakan Citra Sentinel-2A Di TAHURA Ngurah Rai Bali." Journal of Marine and Aquatic Sciences 5, no. 2 (January 15, 2019): 192. http://dx.doi.org/10.24843/jmas.2019.v05.i02.p05.
Full textAbstract:
The mangrove forest of TAHURA Ngurah Rai is one of the mangrove ecosystems in Bali that suffered damages and density changes due to natural factors and human activities. Remote sensing is one of the technology that can be used to estimate the density of mangrove canopy in TAHURA Ngurah Rai. The purpose of this study was to find the best vegetation index for estimating mangrove canopy density out and map it spatially using Sentinel-2A image. The method of this research is using vegetation index NDVI, EVI and mRE-SR to estimate mangrove canopy density. Field data was collected using Stratified Random and Proportional Sampling method by taking photo of the density of canopy using camera with Fish Eye lens on 34 plot. The results of this study show the satistic test of the linear model of the vegetation index with the mangrove canopy density value on the NDVI index (r = 0.8165, R2 = 0.6667, RMSE = ± 8.1508), EVI (r = 0.8597, R2 = 0.7390, RMSE = ± 7.8117), and mRE-SR (r = 0.9277, R2 = 0.8607, RMSE = ± 4.9571). The conclusion of this research is mRE-SR vegetation index able to map mangrove canopy density better than NDVI and EVI vegetation index with 86.07% accuracy. The mangrove spatial distribution generated from the mRE-SR model is 1002.22 Ha with 3.24 Ha categorized as very high density, 94.82 Ha categorized as high density, 333 Ha categorized as medium density, 402.38 Ha categorized as low density, and categorized as very low density is up to 168.76 Ha.
23
Putra, Bagas Utomo, Anak Agung Keswari Krisnandika, and I. Made Agus Dharmadiatmika. "Pengaruh Kombinasi Kerapatan Kanopi Pohon terhadap Kenyamanan Termal di Lapangan Puputan Margarana, Denpasar." Jurnal Lanskap Indonesia 14, no. 1 (April 1, 2022): 16–21. http://dx.doi.org/10.29244/jli.v14i1.38646.
Full textAbstract:
Puputan Margarana as a city park is used as a public space that can accommodate outdoor activities for its users. Comfort is an important factor consider for users to conduct activity inside. User comfort level can be measured using the thermal humidity index formula based on the temperature and humidity variables. The temperature and humidity can be influenced by the presence of vegetation, especially trees. Differences in tree species composition will cause differences in the canopy density formed. This study aims to identify the effect of the combined tree canopy density on thermal comfort. This research method begins with determining the sample point based on the combination of canopy density to areas that are not shaded by the canopy. Then, the canopy was photographed at the sample point for analysis using Hemiview 2.1 software to obtain the leaf area index (LAI) value. Furthermore, independent samples T test, assessment of thermal comfort, correlation analysis and linear regression between variables. The results of the analysis show that there is a strong correlation between LAI with temperature, humidity, and THI. There were significant differences between THI at sample points 1, 2, 4, and 5 with LAI 1.68-4.53 against THI without canopy shade. Meanwhile, THI at sample points 3 and 6 with LAI 0.96-1.36 was not significantly different from THI without canopy shade. This shows that the combination of tree canopy density in this study has an effect on thermal comfort. This shows that canopy density can be one of the considerations in selecting trees for landscape design for climate engineering purposes.
24
Umarhadi, Deha Agus, and Projo Danoedoro. "Comparing canopy density measurement from UAV and hemispherical photography: an evaluation for medium resolution of remote sensing-based mapping." International Journal of Electrical and Computer Engineering (IJECE) 11, no. 1 (February 1, 2021): 356. http://dx.doi.org/10.11591/ijece.v11i1.pp356-364.
Full textAbstract:
UAV and hemispherical photography are common methods used in canopy density measurement. These two methods have opposite viewing angles where hemispherical photography measures canopy density upwardly, while UAV captures images downwardly. This study aims to analyze and compare both methods to be used as the input data for canopy density estimation when linked with a lower spatial resolution of remote sensing data i.e. Landsat image. We correlated the field data of canopy density with vegetation indices (NDVI, MSAVI, and AFRI) from Landsat-8. The canopy density values measured from UAV and hemispherical photography displayed a strong relationship with 0.706 coefficient of correlation. Further results showed that both measurements can be used in canopy density estimation using satellite imagery based on their high correlations with Landsat-based vegetation indices. The highest correlation from downward and upward measurement appeared when linked with NDVI with a correlation of 0.962 and 0.652, respectively. Downward measurement using UAV exhibited a higher relationship compared to hemispherical photography. The strong correlation between UAV data and Landsat data is because both are captured from the vertical direction, and 30 m pixel of Landsat is a downscaled image of the aerial photograph. Moreover, field data collection can be easily conducted by deploying drone to cover inaccessible sample plots.
25
Kay, Heather, Maurizio Santoro, Oliver Cartus, Pete Bunting, and Richard Lucas. "Exploring the Relationship between Forest Canopy Height and Canopy Density from Spaceborne LiDAR Observations." Remote Sensing 13, no. 24 (December 7, 2021): 4961. http://dx.doi.org/10.3390/rs13244961.
Full textAbstract:
Forest structure is a useful proxy for carbon stocks, ecosystem function and species diversity, but it is not well characterised globally. However, Earth observing sensors, operating in various modes, can provide information on different components of forests enabling improved understanding of their structure and variations thereof. The Ice, Cloud and Elevation Satellite (ICESat) Geoscience Laser Altimeter System (GLAS), providing LiDAR footprints from 2003 to 2009 with close to global coverage, can be used to capture elements of forest structure. Here, we evaluate a simple allometric model that relates global forest canopy height (RH100) and canopy density measurements to explain spatial patterns of forest structural properties. The GLA14 data product (version 34) was applied across subdivisions of the World Wildlife Federation ecoregions and their statistical properties were investigated. The allometric model was found to correspond to the ICESat GLAS metrics (median mean squared error, MSE: 0.028; inter-quartile range of MSE: 0.022–0.035). The relationship between canopy height and density was found to vary across biomes, realms and ecoregions, with denser forest regions displaying a greater increase in canopy density values with canopy height, compared to sparser or temperate forests. Furthermore, the single parameter of the allometric model corresponded with the maximum canopy density and maximum height values across the globe. The combination of the single parameter of the allometric model, maximum canopy density and maximum canopy height values have potential application in frameworks that target the retrieval of above-ground biomass and can inform on both species and niche diversity, highlighting areas for conservation, and potentially enabling the characterisation of biophysical drivers of forest structure.
26
Jain, Theresa B., Russell T. Graham, and Penelope Morgan. "Western white pine growth relative to forest openings." Canadian Journal of Forest Research 34, no. 11 (November 1, 2004): 2187–98. http://dx.doi.org/10.1139/x04-094.
Full textAbstract:
In northern Rocky Mountains moist forests, timber harvesting, fire exclusion, and an introduced stem disease have contributed to the decline in western white pine (Pinus monticola Dougl. ex D. Don) abundance (from 90% to 10% of the area). Relations between canopy openings (0.1–15 ha) and western white pine growth within different physical settings are identified. Objectives include relating western white pine seedling and sapling growth to canopy opening attributes (defined by fisheye photography), identifying western white pine competitive thresholds (occupancy, competitive advantage, free-to-grow status) in relation to opening size, and relating canopy opening attributes to overstory density descriptors. We sampled 620 western white pine plus competing trees, canopy opening characteristics, landscape position, and overstory density descriptors. Analysis included log-linear and polynomial regression. Visible sky (canopy opening) and tree age were significantly related to growth of selected pines. Radiation explained less variation in growth than canopy opening. Thresholds for western white pine to occupy a site (>23% canopy opening), gain a competitive advantage (>50% canopy opening), and achieve free-to-grow status (>92% canopy opening) over western hemlock were developed. There was a significant although weak (R2 < 0.12) relation between canopy opening and overstory density descriptors.
27
Japa, Lalu, Karnan Karnan, and Didik Santoso. "Community of Mangrove Category Tree and Sapling in The Sekotong Bay, West Lombok." Jurnal Biologi Tropis 21, no. 2 (June 18, 2021): 441. http://dx.doi.org/10.29303/jbt.v21i2.2698.
Full textAbstract:
Community of mangrove in the Bay of Sekotong, West Lombok was studied to know the species composition, individual density of each species, and percentage covering of mangrove canopy. Total 28 plots of 10 m x 10 m were set in 9 transects in 5 stations. Photographs of canopy covering and mangrove community composition were analyzed by using software ImageJ and template spreadsheet 10x10, the new version of March 2018. The community of mangrove of Sekotong bay, West Lombok consists of 8 species, 5 genera, and 4 families. Rhizophora apiculata & Rhizophora stylosa were recorded in seven of nine transects (78% of transect). Ceriops tagal was a species that was also recorded to have the highest density (3700 trees/ha) in transect SKTM02B. The average density of the mangrove sapling category was higher than the mangrove tree category. The three highest covering percentages of canopi mangrove community took place in transects SKTM01A, SKTM01B, and SKTM04T.
28
Himayah, Shafira, Hartono Hartono, and Projo Danoedoro. "Pemanfaatan Citra Landsat 8 Multitemporal dan Model Forest Canopy Density (FCD) untuk Analisis Perubahan Kerapatan Kanopi Hutan di Kawasan Fakultas Geografi Universitas Gadjah Mada Gunung Kelud, Jawa Timur." Majalah Geografi Indonesia 31, no. 1 (April 21, 2017): 65. http://dx.doi.org/10.22146/mgi.24236.
Full textAbstract:
Penginderaan jauh memiliki keunggulan dalam hal resolusi temporal yang dapat dimanfaatkan untuk meneliti perubahan suatu obyek dalam waktu yang berbeda. Hutan Gunung Kelud mengalami perubahan setelah erupsi tahun 2014. Perubahan tersebut dapat dianalisis dengan memanfaatkan teknologi penginderaan jauh melalui citra multitemporal. Penelitian ini bertujuan untuk mengkaji kemampuan citra Landsat 8 multitemporal dan Forest Canopy Density (FCD) untuk perubahan kerapatan kanopi di Hutan Lindung Gunung Kelud sebelum dan sesudah erupsi tahun 2014.Citra penginderaan jauh yang digunakan adalah citra Landsat 8 perekaman 26 Juni 2013 dan 4 September 2015. Metode yang digunakan adalah pemodelan FCD yang menghasilkan kerapatan kanopi per piksel. Hasil pemodelan FCD kemudian digunakan untuk menganalisis perubahan kerapatan kanopi setelah erupsi. Berdasarkan penelitan ini didapatkan hasil bahwa citra Landsat 8 dapat dipergunakan untuk mengetahui kerapatan kanopi Hutan Lindung Gunung Kelud sebelum dan setelah erupsi dengan masing-masing akurasi sebesar 83,73% dan 81,14%. Terjadi perubahan luas kerapatan kanopi setelah erupsi, dimana terdapat 8833,95 Ha hutan yang mengalami penurunan kerapatan kanopi, sedangkan hutan dengan kerapatan kanopi yang tetap adalah seluas 2149,38 Ha, dan hutan yang mengalami peningkatan kerapatan kanopi adalah seluas 1643,31 Ha. Remote sensing has an advantage in terms of temporal resolution that can be exploited to examine the changes of an object in different times. Gunung Kelud Forest is changing after the eruption in 2014. The changes can be analyzed by utilizing remote sensing technology through multitemporal imagery. This study aims to examine the capabilities of Landsat 8 multitemporal and Forest Canopy Density (FCD) images for changes in canopy density in Kelud Protection Forest before and after the eruption in 2014. Remote sensing imagery used is Landsat 8 image recording June 26, 2013, and September 4, 2015, The method used is FCD modeling that produces a density of the canopy per pixel. FCD modeling results are then used to analyze changes in density of the canopy after the eruption. Based on this research, it can be concluded that Landsat 8 image can be used to determine the density of canopy of Kelud Protection Forest before and after eruption with 83.73% and 81.14% accuracy respectively. There was a change in the area of the canopy density after the eruption, where there was 8833.95 ha of forest that experienced a decrease in canopy density, whereas forests with fixed canopy densities were 2149.38 Ha, and forests with an increase in canopy density were 1643.31 Ha.
29
Shin, Patrick, Temuulen Sankey, Margaret Moore, and Andrea Thode. "Evaluating Unmanned Aerial Vehicle Images for Estimating Forest Canopy Fuels in a Ponderosa Pine Stand." Remote Sensing 10, no. 8 (August 11, 2018): 1266. http://dx.doi.org/10.3390/rs10081266.
Full textAbstract:
Forests in the Southwestern United States are becoming increasingly susceptible to large wildfires. As a result, forest managers are conducting forest fuel reduction treatments for which spatial fuels and structure information are necessary. However, this information currently has coarse spatial resolution and variable accuracy. This study tested the feasibility of using unmanned aerial vehicle (UAV) imagery to estimate forest canopy fuels and structure in a southwestern ponderosa pine stand. UAV-based multispectral images and Structure-from-Motion point clouds were used to estimate canopy cover, canopy height, tree density, canopy base height, and canopy bulk density. Estimates were validated with field data from 57 plots and aerial photography from the U.S. Department of Agriculture National Agriculture Imaging Program. Results indicate that UAV imagery can be used to accurately estimate forest canopy cover (correlation coefficient (R2) = 0.82, root mean square error (RMSE) = 8.9%). Tree density estimates correctly detected 74% of field-mapped trees with a 16% commission error rate. Individual tree height estimates were strongly correlated with field measurements (R2 = 0.71, RMSE = 1.83 m), whereas canopy base height estimates had a weaker correlation (R2 = 0.34, RMSE = 2.52 m). Estimates of canopy bulk density were not correlated to field measurements. UAV-derived inputs resulted in drastically different estimates of potential crown fire behavior when compared with coarse resolution LANDFIRE data. Methods from this study provide additional data to supplement, or potentially substitute, traditional estimates of canopy fuel.
30
Rosati, Adolfo, Damiano Marchionni, Dario Mantovani, Luigi Ponti, and Franco Famiani. "Intercepted Photosynthetically Active Radiation (PAR) and Spatial and Temporal Distribution of Transmitted PAR under High-Density and Super High-Density Olive Orchards." Agriculture 11, no. 4 (April 15, 2021): 351. http://dx.doi.org/10.3390/agriculture11040351.
Full textAbstract:
We quantified the photosynthetically active radiation (PAR) interception in a high-density (HD) and a super high-density (SHD) or hedgerow olive system, by measuring the PAR transmitted under the canopy along transects at increasing distance from the tree rows. Transmitted PAR was measured every minute, then cumulated over the day and the season. The frequencies of the different PAR levels occurring during the day were calculated. SHD intercepted significantly but slightly less overall PAR than HD (0.57 ± 0.002 vs. 0.62 ± 0.03 of the PAR incident above the canopy) but had a much greater spatial variability of transmitted PAR (0.21 under the tree row, up to 0.59 in the alley center), compared to HD (range: 0.34–0.43). This corresponded to greater variability in the frequencies of daily PAR values, with the more shaded positions receiving greater frequencies of low PAR values. The much lower PAR level under the tree row in SHD, compared to any position in HD, implies greater self-shading in lower-canopy layers, despite similar overall interception. Therefore, knowing overall PAR interception does not allow an understanding of differences in PAR distribution on the ground and within the canopy and their possible effects on canopy radiation use efficiency (RUE) and performance, between different architectural systems.
31
Anurogo, Wenang, Muhammad Zainuddin Lubis, and Mir'atul Khusna Mufida. "Modified Soil-Adjusted Vegetation Index In Multispectral Remote Sensing Data for Estimating Tree Canopy Cover Density at Rubber Plantation." Journal of Geoscience, Engineering, Environment, and Technology 3, no. 1 (March 1, 2018): 15. http://dx.doi.org/10.24273/jgeet.2018.3.01.1003.
Full textAbstract:
Forest inventories such as tree canopy density information require a long time and high costs, especially on extensive forest coverage. Remote sensing technology that directly captures the surface vegetation character with extensive recording coverage can be used as an alternative to carrying out such inventory activities. This research aims to determine the level of vegetation canopy cover density on rubber plants that became the location of the research and know the accuracy of the resulting data. The method used in this research is a combination of remote sensing image interpretation, geographic information system, and field measurement. Information retrieval from remote sensing data is done by using ASTER data imagery. This stage includes three parts, namely: pre-field stage, field stage, and post-field stage. The pre-field stage includes the collection of data to be used (including literature studies related to the theme of the study), image processing (geometric and radiometric correction), cropping, masking, land cover classification, vegetation index transformation, and sample determination. The final result of data processing showed that the density of the vegetation canopy in the research area ranged between 7.31 – 12.952 cm / m2 in each grade of vegetation density. These values indicate the range of low-class vegetation canopy cover density to high-class vegetation canopy cover density in the research area. In this research error rate or root mean square error obtained from the calculation of canopy cover density is equal to 1.89.
32
Gaskin, R. E., D. W. Manktelow, S. Cook, W. A. May, and R. M. Van_Leeuwen. "Effects of canopy density on spray deposition in kiwifruit." New Zealand Plant Protection 66 (January 8, 2013): 194–98. http://dx.doi.org/10.30843/nzpp.2013.66.5607.
Full textAbstract:
A study was undertaken to evaluate the effects of canopy density on efficiency of spray deposition on kiwifruit pergola canopies A dense canopy was pruned to also provide medium and lighter density canopies Airblast sprays (water fluorescent dye) were applied in typical dilute application volumes to the three canopies Deposits were measured at four height positions through the canopy in both the centreofrow and leader zones Mean deposits on the dense canopy (at 2000 litres/ha) were inadequate and lowest in all zones; approximately 40 less than the medium (1500 litres/ha) and light (1000 litres/ha) canopies This suggests dense pergola canopies cannot be adequately covered by protectant sprays applied in the typical dilute volumes used by the kiwifruit industry even with good sprayer setup Spray deposits on all foliage zones in the medium and light canopies were generally acceptable confirming that pergola canopies can be fully protected with groundapplied sprays if they are managed to reduce their density
33
Lim, K., C. Hopkinson, and P. Treitz. "Examining the effects of sampling point densities on laser canopy height and density metrics." Forestry Chronicle 84, no. 6 (December 1, 2008): 876–85. http://dx.doi.org/10.5558/tfc84876-6.
Full textAbstract:
Forest resource managers rely on the information extracted from forest resource inventories to manage forests sustainably and efficiently, thereby supporting more precise decision-making. Light detection and ranging (LiDAR) is a relatively new technology that has proven to enhance forest resource inventories. However, the relationship between LiDAR sampling point density (which is directly related to acquisition and processing costs) and accuracy and precision of forest variable estimation has not yet been established across a range of forest ecosystems. In this study, 2 airborne LiDAR surveys using the same sensor, but configured with disparate parameters, were carried out over the York Regional Forest near Toronto, Canada producing 2 data sets characterized by different sampling point densities. The effects of 2 sampling point densities on 23 laser canopy height and density metrics typically used in forest studies at the plot level were examined with comparisons grouped by first and last return data. The minimum (hmin) and maximum (hmax) laser canopy heights were statistically different for first and last returns. The proportion of laser returns (i.e., canopy density) in the upper (d1) and lower (d10) range of laser canopy heights was statistically different for the first returns, whereas only a single canopy density metric was different for the last returns (d9). These results suggest that changes in sampling point density (due to changes in scan angle and altitude) only affect laser canopy height and density metrics that are characterized by the small percentage of returns from the very top (hmax; d1) and base of the canopy (hmin; d10) (i.e., those metrics that characterize the tail ends of the distributions of laser canopy heights). Consequently, higher sampling point densities may add little value to current LiDAR forest research or operations at the stand level, as metrics derived from the canopy profile can be implemented for biophysical variable estimation. Implications for forest management are in terms of identifying which aspects of LiDAR project design: a) impact the quality and cost-effectiveness of derived FRI information; b) should be specified within a LiDAR request for proposals; or c) scrutinized within LiDAR project tender documentation. Key words: LiDAR, airborne laser scanning, FRI, canopy profile, biophysical variables, sampling density
34
Mahmud, Kare, Paula Ibell, Carole Wright, Zac Scobell, John Wilkie, and Ian Bally. "Light Relation in Intensive Mango Orchards." Proceedings 36, no. 1 (March 8, 2020): 122. http://dx.doi.org/10.3390/proceedings2019036122.
Full textAbstract:
The amount of light intercepted by a tree and its distribution within the canopy is critical in optimizing tree photosynthesis efficiency, carbon partitioning and productivity. Here we compare light relations in experimental high-density mango orchard systems with current commercial orchards. A baseline study of current commercial mango orchards showed a maximum light interception of approximately 67% was reached in trees aged between 26-31 years old, with canopy volume of approximately 15,187 m3/ha. Light interception did not significantly increase beyond 67% regardless of increase in canopy volume per hectare or the increase in orchard age. In these conventional orchards, maximum yields were reached approximately 16 t/ha when light interception was around 49% and as light interception increased above 49%, yields declined. In the high density orchard systems, light interception increased with canopy volume, with high density systems intercepting more available light than medium and low density orchard systems. In 5 year old high-density, espalier trained trees with approximately 5000 m3/ha canopy volume, yields reached close to 50 t/ha at 40% light interception. Trees trained as single leader or espalier had more evenly distributed light in the inner canopy compared to conventionally closed vase trained trees. in current commercial orchards, increasing the canopy volume and light interception above the maximums noted above had no benefit to increase economic returns whereas in high density mango orchards with alternate tree training, yields increases more than four times early in the orchards development. Further productivity gains are likely as the experimental high density have yet to fill their allocated space in the orchard.
35
Ji, Yongjie, Jimao Huang, Yilin Ju, Shipeng Guo, and Cairong Yue. "Forest structure dependency analysis of L-band SAR backscatter." PeerJ 8 (September 30, 2020): e10055. http://dx.doi.org/10.7717/peerj.10055.
Full textAbstract:
Forest structure plays an important role in forest biomass inversion using synthetic aperture radar (SAR) backscatter. Synthetic aperture radar (SAR) sensors with long-wavelength have the potentiality to provide reliable and timely forest biomass inversion for their ability of deep penetration into the forest. L-band SAR backscatter shows useful for forest above-ground biomass (AGB) estimation. However, the way that forest structure mediating the biomass-backscatter affects the improvement of the related biomass estimation accuracy. In this paper, we have investigated L-band SAR backscatter sensitivity to forests with different mean canopy density, mean tree height and mean DBH (diameter at breast height) at the sub-compartment level. The forest species effects on their relationship were also considered in this study. The linear correlation coefficient R, non-linear correlation parameter, Maximal Information Coefficient (MIC), and the determination coefficient R2 from linear function, Logarithmic function and Quadratic function were used in this study to analyze forest structural properties effects on L-band SAR backscatter. The HV channel, which is more sensitive than HH to forest structure parameters, was chosen as the representative of SAR backscatter. 6037 sub-compartment were involved in the analysis. Canopy density showed a great influence on L-band backscatter than mean forest height and DBH. All of the R between canopy density and L-band backscatter were greater than 0.7 during the forest growth cycle. The sensitivity of L-band backscatter to mean forest height depends on forest canopy density. When canopy density was lower than 0.4, R values between mean forest height are smaller than 0.5. In contrast, the values of R were greater than 0.8 if canopy density was higher than 0.4. The sensitivity SAR backscatter to DBH fluctuated with canopy density, but it only showed obvious sensitivity when canopy density equals to 0.6, where both the linear and non-liner correlation values are higher than others. However, their effects on L-bang HV backscatter are affected by forest species, the effects on three forest structural parameters depend on tree species.
36
Huffman, Ronald D., Mary Ann Fajvan, and Petra Bohall Wood. "Effects of residual overstory on aspen development in Minnesota." Canadian Journal of Forest Research 29, no. 2 (February 1, 1999): 284–89. http://dx.doi.org/10.1139/x98-202.
Full textAbstract:
The effects of different amounts of residual canopy on stand development of quaking aspen (Populus tremuloides Michx.) were examined in a chronosequence of 32 stands spanning 6-10 years since harvest. Residual canopy covers ranged from 0 to 65%, and residual basal areas ranged from 0 to 14.4 m2/ha. Aspen regeneration densities ranged from 7130 to 43 672 stems/ha. Regeneration stem density was affected primarily by residual canopy cover (R2 = 0.27, P = 0.0001) and secondarily by stand age (R2 = 0.09, P = 0.004). Aspen density decreased significantly with increasing residual canopy cover for 7-year-old and 8-year-old regeneration. Residual canopy cover did not significantly affect aspen density in 9-year-old regeneration (R2 = 0.02, P = 0.579) but was negatively related to total height of 9-year-old codominant aspens (R2 = 0.49, P = 0.002). Canopy cover was a more accurate representation of the amount of shade the regeneration received than the density or basal area of residual trees. However, the low value of the coefficient of determination from a multiple-regression model indicates that considerable variation in stem densities and height was unexplained by residual canopy cover, even though it was the best predictor of the variables measured.
37
Ex, Seth A., Frederick W. Smith, Tara L. Keyser, and Stephanie A. Rebain. "Estimating Canopy Bulk Density and Canopy Base Height for Interior Western US Conifer Stands." Forest Science 62, no. 6 (December 15, 2016): 690–97. http://dx.doi.org/10.5849/forsci.15-118.
Full text
38
Olien, W. C., R. E. Williamson, C. E. Hood, D. R. Decoteau, and D. C. Coston. "INTERACTION OF TRAINING SYSTEM, SUMMER PRUNING AND ROOT PRUNING ON YIELD AND CANOPY DENSITY OF PEACH." HortScience 27, no. 11 (November 1992): 1168g—1168. http://dx.doi.org/10.21273/hortsci.27.11.1168g.
Full textAbstract:
Factorial combinations of ± root pruning (RP) and ± summer pruning (SP) were initiated in 1991 as subplots within a Redhaven/Lovell study of orchard training systems: Open Center (OC), Y-Trellis (YT), Central Leader (CL), and Meadow Orchard (MO) established in 1985. Root pruning was imposed at bloom (March 28) at 76 cm from the trunk to a depth of 45 cm. Summer pruning consisted of preharvest removal of water sprouts (June 5). Canopy density, quantified by transmittance of PAR radiation through the canopy, was greatest in OC and MO and least in YT and CL systems. SP and RP treatments further reduced canopy density by 35 to 80%. There were no main or interactive effects of SP and RP on 1991 yields or fruit quality, and also no interactive effects of orchard systems with SP and RP. Thus, SP and RP reduced canopy density without negative effects on fruit. RP, however, advanced harvest date by ca 4 days. A parallel study was also initiated in 1991 to determine the effects of root pruning distance (30, 60, 90 cm from the trunk, or no RP) on canopy density, yield, and fruit quality of mature, OC-trained Redhaven/ and Jefferson/Lovell. Reduction in canopy density without loss of yield or fruit size was obtained at a RP distance between 60 and 90 cm.
39
Kabakoff, Randy P., and Robin L. Chazdon. "Effects of canopy species dominance on understorey light availability in low-elevation secondary forest stands in Costa Rica." Journal of Tropical Ecology 12, no. 6 (November 1996): 779–88. http://dx.doi.org/10.1017/s0266467400010038.
Full textAbstract:
ABSTRACTThe effect of canopy species dominance on understorey light availability in secondary forests was examined for Pentaclethra macroloba and Goethalsia meiantha, two common tree species with contrasting canopy architecture at La Selva Biological Station in the Atlantic lowlands of Costa Rica. In each of six 12- to 16-year-old successional stands dominated by one of these species, relative abundance and basal area of the focal species were determined within a 20 m × 50 m plot. Light availability at 1 m height was measured within each plot using a Licor-2000 Plant Canopy Analyzer at 27 locations and by analysing hemispherical photographs taken at 10 locations. Across stands, mean LAI values were significantly negatively correlated with canopy openness. Understorey microsites beneath Pentaclethra had significantly higher light availability than microsites beneath Goethalsia. Across stands, however, light availability was not correlated with either total basal area or stem density of trees ≥10 cm DBH. These results indicate that basal area and stem density of trees in the upper levels of the forest canopy are poor predictors of light penetration to the understorey. One hypothesis suggested here is that dense subcanopy and understorey vegetation in tropical secondary forests can strongly influence understorey light levels. Alternatively, light transmittance characteristics of the upper forest canopy may be influenced by species-specific differences in canopy architecture or foliage density that vary independently from tree diameter and density.
40
Brown, Helen, Katrina Proust, Barry Newell, Jeffery Spickett, Tony Capon, and Lisa Bartholomew. "Cool Communities—Urban Density, Trees, and Health." International Journal of Environmental Research and Public Health 15, no. 7 (July 22, 2018): 1547. http://dx.doi.org/10.3390/ijerph15071547.
Full textAbstract:
A move towards more compact and climate-resilient cities is being encouraged around the world. As part of these plans, there is a need to manage the potential conflict between increasing urban densities and the extent of tree canopy in cities. Reductions in tree canopy are a major contributor to the urban heat island (UHI) effect, which will act to reduce rather than increase climate resilience in many cities. A systems thinking approach called Collaborative Conceptual Modelling was used to study the interaction between urban infill, tree canopy, and human health in Perth, Australia. The results indicated that under current planning policies and development practices, the behaviour of the system is dominated by the drive towards higher housing densities. While this may result in the attainment of urban infill targets, it is likely to lead to a reduction in tree canopy, higher temperatures, and a decrease in a range of other benefits provided by trees. Recommended actions to overcome this behaviour were determined by the identification of leverage points in the system. These included a shift to a sustainable development paradigm that places greater value on the environmental and social benefits provided by trees and a greater emphasis on a climate-resilient future. Market and legislative mechanisms should be integrated into the city’s greening strategy and development plans to ensure the protection of existing trees and the inclusion of new trees on public and private land.
41
Bateman, Tyler J., and Scott E. Nielsen. "Direct and Indirect Effects of Overstory Canopy and Sex-Biased Density Dependence on Reproduction in the Dioecious Shrub Shepherdia canadensis (Elaeagnaceae)." Diversity 12, no. 1 (January 19, 2020): 37. http://dx.doi.org/10.3390/d12010037.
Full textAbstract:
This study assessed the reproductive success of a temperate dioecious shrub, Canada buffaloberry, Shepherdia canadensis (L.) Nutt., in central Alberta, Canada, by examining the effects of spatial patterns and overstory canopy on flower and fruit production. S. canadensis is more abundant and productive (more fruit) at forest edges and in forest gaps, suggesting a dependence on higher light conditions than is typical of late-seral forests. We used path analysis to demonstrate that flower and fruit production exhibited density-dependent effects at a scale of 50 m2 around focal female plants. Fruit production was positively affected by male intraspecific density (pollen supply) and negatively affected by female intraspecific density (pollen competition), but not correlated with overall intraspecific density. The effects of sex-differentiated density are partly due to pollinator responses to male plant density. Flower production was positively affected by overall intraspecific density. A pollen supplementation trial doubled fruit production relative to a control, demonstrating that local male density (pollen availability) and pollinator activity can limit fruit production in S. canadensis. Canopy cover was negatively related to both flower and total fruit production, with approximately one-third (34%) of the total effect of canopy on fruit production due to the effect of canopy on flower production. The commonly observed negative association between canopy cover and fruit production in buffaloberry, therefore, is partly a result of the reduction first in flower number and second in fruit set. This study clarifies the mechanisms associated with the often-noted observation, but not previously assessed at the level of individuals, that reproductive output in S. canadensis is density dependent, limited by canopy cover through reductions in both flowering and fruit set, and pollinator limited. These findings hold implications for managing animal species that depend on the fruit of S. canadensis and suggest future directions for research on dioecious and actinorhizal species.
42
Fidalgo-González, L. A., S. Arellano-Pérez, J. G. Álvarez-González, F. Castedo-Dorado, A. D. Ruiz-González, and E. González-Ferreiro. "Estimación de la distribución vertical de combustibles finos del dosel de copas en masas de Pinus sylvestris empleando datos LiDAR de baja densidad." Revista de Teledetección, no. 53 (June 27, 2019): 1. http://dx.doi.org/10.4995/raet.2019.11241.
Full textAbstract:
<p>Canopy fuel load, canopy bulk density and canopy base height are structural variables used to predict crown fire initiation and spread. Direct measurement of these variables is not functional, and they are usually estimated indirectly by modelling. Advances in fire behaviour modelling require accurate and landscape scale estimates of the complete vertical distribution of canopy fuels. The goal of the present study is to model the vertical profile of available canopy fuels in Scots pine stands by using data from the Spanish national forest inventory and low-density LiDAR data (0.5 first returns m<sup>–2</sup>) provided by Spanish PNOA project (Plan Nacional de Ortofotografía Aérea). In a first step, the vertical distribution of the canopy fuel load was modelled using the Weibull probability density function. In a second step, a system of models was fitted to relate the canopy variables to Lidar-derived metrics. Models were fitted simultaneously to compensate the effects of the inherent cross-model correlation between errors. Heteroscedasticity was also analyzed, but correction in the fitting process was not necessary. The estimated canopy fuel load profiles from LiDAR-derived metrics explained 41% of the variation in canopy fuel load in the analysed plots. The proposed models can be used to assess the effectiveness of different forest management alternatives for reducing crown fire hazard.</p>
43
Mitra, S. K., B. Ghosh, and P. K. Pathak. "High density orcharding and canopy management in guava." Acta Horticulturae, no. 1205 (June 2018): 955–58. http://dx.doi.org/10.17660/actahortic.2018.1205.123.
Full text
44
Kwon, Tae-Hyub, Woo-Kyun Lee, Doo-Ahn Kwak, Tae-Jin Park, Jong-Yoel Lee, Suk-Young Hong, Cui Guishan, and So-Ra Kim. "Forest Canopy Density Estimation Using Airborne Hyperspectral Data." Korean Journal of Remote Sensing 28, no. 3 (June 30, 2012): 297–305. http://dx.doi.org/10.7780/kjrs.2012.28.3.297.
Full text
45
Zhang, Geng, Chengchang Zhang, and Huayu Zhang. "Improved K-means algorithm based on density Canopy." Knowledge-Based Systems 145 (April 2018): 289–97. http://dx.doi.org/10.1016/j.knosys.2018.01.031.
Full text
46
Johansson, Tord. "Estimating canopy density by the vertical tube method." Forest Ecology and Management 11, no. 1-2 (June 1985): 139–44. http://dx.doi.org/10.1016/0378-1127(85)90063-5.
Full text
47
Bednarz, Craig W., Robert L. Nichols, and Steve M. Brown. "Plant Density Modifies Within‐Canopy Cotton Fiber Quality." Crop Science 46, no. 2 (March 2006): 950–56. http://dx.doi.org/10.2135/cropsci2005.08-0276.
Full text
48
Botequim, Brigite, Paulo M. Fernandes, José G. Borges, Eduardo González-Ferreiro, and Juan Guerra-Hernández. "Improving silvicultural practices for Mediterranean forests through fire behaviour modelling using LiDAR-derived canopy fuel characteristics." International Journal of Wildland Fire 28, no. 11 (2019): 823. http://dx.doi.org/10.1071/wf19001.
Full textAbstract:
Wildfires cause substantial environmental and socioeconomic impacts and threaten many Spanish forested landscapes. We describe how LiDAR-derived canopy fuel characteristics and spatial fire simulation can be integrated with stand metrics to derive models describing fire behaviour. We assessed the potential use of very-low-density airborne LiDAR (light detection and ranging) data to estimate canopy fuel characteristics in south-western Spain Mediterranean forests. Forest type-specific equations were used to estimate canopy fuel attributes, namely stand height, canopy base height, fuel load, bulk density and cover. Regressions explained 61–85, 70–85, 38–96 and 75–95% of the variability in field estimated stand height, canopy fuel load, crown bulk density and canopy base height, respectively. The weakest relationships were found for mixed forests, where fuel loading variability was highest. Potential fire behaviour for typical wildfire conditions was predicted with FlamMap using LiDAR-derived canopy fuel characteristics and custom fuel models. Classification tree analysis was used to identify stand structures in relation to crown fire likelihood and fire suppression difficulty levels. The results of the research are useful for integrating multi-objective fire management decisions and effective fire prevention strategies within forest ecosystem management planning.
49
Somda, Zana C., and Stanley J. Kays. "Sweet Potato Canopy Architecture: Branching Pattern." Journal of the American Society for Horticultural Science 115, no. 1 (January 1990): 33–38. http://dx.doi.org/10.21273/jashs.115.1.33.
Full textAbstract:
The effect of the plant density (15, 30, 45 × 96-cm spacing) on the branching pattern `Jewel' sweet potato [Ipomoea batatas (L.) Lam.] was determined bi-weekly for 18 weeks. Plant density effects were significant for the number of branches formed and timing of branch formation. Plant density did not affect the type of branches formed (e.g., primary, secondary, and tertiary), but did alter the timing of induction during the growing season. By the end of the growing period, the ratios for the number of primary to secondary branches were 1.5:1, 1.3:1, and 0.6:1 at the 15-, 30-, and 45-cm spacing, respectively. Few tertiary branches were formed, but were present on some plants at each spacing. Tertiary branches most commonly occurred on plants at the widest spacing. While the number of branches per plant was highly plastic and inversely related to plant density, nodes per branch and internode length were not significantly affected. Average internode length per branch decreased with descending branch hierarchy (i,e., main stem < primary branch < secondary branch). `Jewel' sweet potato responded to increased space available largely through production of additional branches with the modification of branching pattern increasing as the season progressed.
50
Dzikrillah, F. D., M. T. S. Budiastuti, and Sugihardjo. "Analysis of the role of plant canopy on hydrological systems." IOP Conference Series: Earth and Environmental Science 905, no. 1 (November 1, 2021): 012116. http://dx.doi.org/10.1088/1755-1315/905/1/012116.
Full textAbstract:
Abstract High rainfall intensity causing high erosion rates in Indonesia. Land cover conditions greatly determine water degradation in the hydrological cycle. The shape and type of plants canopy have significant effect on soil structure and water absorption. This study aimed to examine the role of plant canopy on the value of rainwater canopy escape as a supporter of hydrological cycle. Tree species were determined based on the level of dominance at study site using transect method. The dominant trees are Sea Sengon Tree (Paraserianthes falcataria), Teak Tree (Tectona grandis), Suren Tree (Toona sinensis) and Durian Tree (Durio zibethinus). The results showed that high rainfall intensity with a long rain period affected the amount of canopy escape. Durian Tree has highest canopy density with value of 0.301, and Sengon Laut is the lowest with value of 0.240. The value of passing the canopy of the Suren Tree is lower than the other tree species. The shape of canopy of Suren tree, which is round and oval, also affects the lower pass value of canopy compared to other tree species. The higher the value of canopy density can reduce the value of canopy escape to support the hydrological cycle.