scholarly journals Reconstruction of Piñon–Juniper Woodlands in the Sky Islands of the Davis Mountains, Texas, USA

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1079
Author(s):  
Mohammad M. Bataineh ◽  
Brian P. Oswald ◽  
Hans M. Williams ◽  
Daniel R. Unger ◽  
I-Kuai Hung
Keyword(s):  
Tree Species ◽  
Reference Conditions ◽  
Age Determination ◽  
Niche Differentiation ◽  
Rate Of Change ◽  
Sky Islands ◽  
Davis Mountains ◽  
Study Sites ◽  
Pinus Spp ◽  
Individual Trees

Piñon (Pinus spp. L.)–juniper (Juniperus spp. L.) woodlands’ historical stand structures were recreated to provide reference conditions and document long-term changes in the Sky Islands of the Davis Mountains, Texas. Restoration of these isolated woodlands requires insights into the range of variability in current and historical stand structures, as well as an understanding of the spatiotemporal establishment and recruitment patterns of tree species. With drastic changes in forests and woodlands of the Southwestern United States widely reported, the main objective of this study was to reconstruct woodland tree temporal and spatial establishment patterns. A stratified random sampling approach was used to select two study sites each of 3600 m2 in area. Within each site, all individual trees were mapped, measured, and cored for age determination. Age and tree location data were used to recreate the spatiotemporal patterns of tree species establishment and recruitment. Increments in density of both Mexican piñon (Pinus cembroides var. cembroides Zucc.) and alligator juniper (Juniperus deppeana var. deppeana Steud.) reached 422 trees ha−1 in the 115-year period between 1890 and 2005; a yearly increment of 4 trees ha−1 that did not reflect a rapid rate of change in these piñon–juniper woodlands. Age distributions reflected the multi-cohort nature of these woodlands, and spatial autocorrelation measures were useful in the objective delineation of these cohorts. Temporal and functional niche differentiation of juniper was reflected in the development pattern where alligator juniper served as a pioneer species, exhibited a longer period of substantial recruitment, and had greater recruitment rates than that of Mexican piñon. Recruitment of Mexican piñon and alligator juniper occurred in an episodic fashion, with the majority of recruits being acquired between 1890 and 1949.

scholarly journals Exploratory Studies on Occurrence and Potential Benefits of High Fruit Yielding Reproductive Phenophasic Variants of Pithecellobium dulce in Augmenting Fruit Based Semi-arid Agro Forestry Systems

2019 ◽  
pp. 1-17
Author(s):  
Jai Prakash Narayan
Keyword(s):  
Genetic Diversity ◽  
Natural Population ◽  
Tree Species ◽  
Flowering Phenology ◽  
Reproductive Behaviour ◽  
Arid Climate ◽  
Reproductive Phenology ◽  
Study Sites ◽  
Individual Trees ◽  
Semi Arid

Background: Pithecellobium dulce is a multipurpose legume tree species of high ecological significance. Several reports indicate existence of huge genetic diversity within the natural population of the species. Various morphological parameters have been used to assess intra species genetic diversity, however, there is no report available so far on diversities in reproductive phenology of P. dulce of semi-arid or arid climate. Methods: The present paper is based on assessment of diversity in flowering phenophases through construction of phenological calendar incorporating temporally observable morpho-phenotypic descriptors for reproductive behaviour of individual trees comprising natural population of the species at designated study sites during a period of three years. The study was carried out during September, 2015 and March, 2019 at Ajmer, Rajasthan, India. Data were periodically obtained and statistically analyzed. Results: Majority of trees of flowering stage (89.94%) exhibited normal or winter blooms in which flowering was initiated in almost synchronized manner during December; 10.05% of normal blooming trees inconsistently showed additional early or autumn blooms during either September or October or November; 2.58% of trees exhibited early blooms in which flowering was consistently initiated in the month of September in addition to normal blooms. The overall production and availability of fresh fruits in early-cum-normal episodic blooming trees were greater as compared to only normal blooming trees. Though, the numerical fruit productivity in winter blooms was superior to autumn, the pomometric characteristics were inferior in former in early-cum-normal episodic blooming trees. Conclusion: The methodology is a novel experimental approach to assess diversities in reproductive phenology of seed raised population of high value fruit bearing economically important tree species. The present work explores agronomically valuable variants of P. dulce and also reports causes of appearance of persistent fruits and sporadic in-situ germination of seeds. Based on above findings, the paper also makes evolutionary predictions that how a shift in flowering phenology of P. dulce as exhibited by the elite variants could have long-term implications for reshaping of future landscapes of semi-arid or arid climate. Conclusively, Winter to autumn phenophasic shift in flowering in P. dulce is economically productive, evolutionarily progressive, and environmentally well cued partial retrieval under semi-arid conditions. Moreover, the phenophasic variants could serve as candidate plus trees that deserve out of the season floral management and clonal propagation, thereby the species may get a fillip to status up gradation from minor fruits to major fruit category.

scholarly journals Using Discrete-Point LiDAR to Classify Tree Species in the Riparian Pacific Northwest, USA

2021 ◽  
Vol 13 (14) ◽  
pp. 2647
Author(s):  
Julia Tatum ◽  
David Wallin
Keyword(s):  
Pacific Northwest ◽  
Tree Species ◽  
3D Structure ◽  
Alnus Rubra ◽  
Populus Balsamifera ◽  
Segmentation Method ◽  
Black Cottonwood ◽  
Riparian Landscape ◽  
Individual Trees ◽  
Species Mapping

Practical methods for tree species identification are important for both land management and scientific inquiry. LiDAR has been widely used for species mapping due to its ability to characterize 3D structure, but in structurally complex Pacific Northwest forests, additional research is needed. To address this need and to determine the feasibility of species modeling in such forests, we compared six approaches using five algorithms available in R’s lidR package and Trimble’s eCognition software to determine which approach most consistently identified individual trees across a heterogenous riparian landscape. We then classified segments into Douglas fir (Pseudotsuga menziesii), black cottonwood (Populus balsamifera ssp. trichocarpa), and red alder (Alnus rubra). Classification accuracies based on the best-performing segmentation method were 91%, 92%, and 84%, respectively. To our knowledge, this is the first study to investigate tree species modeling from LiDAR in a natural Pacific Northwest forest, and the first to model Pacific Northwest species at the landscape scale. Our results suggest that LiDAR alone may provide enough information on tree species to be useful to land managers in limited applications, even under structurally challenging conditions. With slight changes to the modeling approach, even higher accuracies may be possible.

scholarly journals Excavation of Red Squirrel (Tamiasciurus hudsonicus) Middens by Bears (Ursus spp.) in Limber Pine (Pinus flexilis) Habitat in Banff National Park, Alberta

2017 ◽  
Vol 130 (4) ◽  
pp. 281 ◽  
Author(s):  
David Hamer
Keyword(s):  
National Park ◽  
Forest Cover ◽  
Habitat Characteristics ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrel ◽  
Limber Pine ◽  
Banff National Park ◽  
Pine Stands ◽  
Study Sites ◽  
Pinus Spp

Bears (Ursus spp.) in North America eat the seeds of several pines (Pinus spp.), including Limber Pine (P. flexilis E. James). Information on use of Limber Pine in Canada is limited to a report of three bear scats containing pine seeds found in Limber Pine stands of southwestern Alberta. After my preliminary fieldwork in Banff National Park revealed that bears were eating seeds of Limber Pine there, I conducted a field study in 2014–2015 to assess this use. Because bears typically obtain pine seeds from cone caches (middens) made by Red Squirrels (Tamiasciurus hudsonicus), I described the abundance, habitat characteristics, and use by bears of Red Squirrel middens in and adjacent to Limber Pine stands at six study sites. On Bow River escarpments, I found abundant Limber Pines (basal area 1–9 m2/ha) and middens (0.8 middens/ha, standard deviation [SD] 0.2). Of 24 middens, 13 (54%) had been excavated by bears, and three bear scats composed of pine seeds were found beside middens. Although Limber Pines occurred on steep, xeric, windswept slopes (mean 28°, SD 3), middens occurred on moderate slopes (mean 12°, SD 3) in escarpment gullies and at the toe of slopes in forests of other species, particularly Douglas-fir (Pseudotsuga menziesii). At the five other study sites, I found little or no use of Limber Pine seeds by bears, suggesting that Limber Pine habitat may be little used by bears unless the pines are interspersed with (non-Limber Pine) habitat with greater forest cover and less-steep slopes where squirrels establish middens. These observations provide managers with an additional piece of information regarding potential drivers of bear activity in the human-dominated landscape of Banff National Park’s lower Bow Valley.

scholarly journals An original method for tree species classification using multitemporal multispectral and hyperspectral satellite data

Silva Fennica ◽  
2020 ◽  
Vol 54 (2) ◽  
Author(s):  
Olga Grigorieva ◽  
Olga Brovkina ◽  
Alisher Saidov
Keyword(s):  
Tree Species ◽  
Original Method ◽  
Hyperspectral Data ◽  
Species Classification ◽  
Multispectral Data ◽  
Spectral Signatures ◽  
Tree Species Classification ◽  
Temporal Features ◽  
Study Sites ◽  
Near Future

This study proposes an original method for tree species classification by satellite remote sensing. The method uses multitemporal multispectral (Landsat OLI) and hyperspectral (Resurs-P) data acquired from determined vegetation periods. The method is based on an original database of spectral features taking into account seasonal variations of tree species spectra. Changes in the spectral signatures of forest classes are analyzed and new spectral–temporal features are created for the classification. Study sites are located in the Czech Republic and northwest (NW) Russia. The differences in spectral reflectance between tree species are shown as statistically significant in the sub-seasons of spring, first half of summer, and main autumn for both study sites. Most of the errors are related to the classification of deciduous species and misclassification of birch as pine (NW Russia site), pine as mixture of pine and spruce, and pine as mixture of spruce and beech (Czech site). Forest species are mapped with accuracy as high as 80% (NW Russia site) and 81% (Czech site). The classification using multitemporal multispectral data has a kappa coefficient 1.7 times higher than does that of classification using a single multispectral image and 1.3 times greater than that of the classification using single hyperspectral images. Potentially, classification accuracy can be improved by the method when applying multitemporal satellite hyperspectral data, such as in using new, near-future products EnMap and/or HyspIRI with high revisit time.

scholarly journals Diversity of Tree Species in Rivers State University, Port Harcourt, Nigeria

2021 ◽  
pp. 67-72
Author(s):  
P. C. Nnadi ◽  
B. B. Otene ◽  
Nwiisator David-Sarogoro
Keyword(s):  
Plant Species ◽  
Tree Species ◽  
Dominant Species ◽  
Species Abundance ◽  
State University ◽  
University Campus ◽  
Management Interventions ◽  
Port Harcourt ◽  
Pinus Spp ◽  
Rivers State

This study was carried out to examine the distribution of plant species in Rivers State University campus at different locations at the Rivers State University Nkpolu-Oroworukwo Port Harcourt Nigeria. The general objective of this study was to examine the Ecological distribution of plant species in Rivers State University campus at different locations. The specific objective was to determine the species abundance of various plants in the study area and also to examine the ecological diversity of tree species in the various groups. The study area was divided into three groups (stations) with the various plants species identified and recorded. Data gotten from the field was analyzed using descriptive statistic and some ecological indices such as Margalef, Mehinick, Shannon diversity, Shannon Wiener, Evenness/Equitability and Simpson dominance.  A total of one thousand Sixty-nine (1069) individual plant were identified with 16, 17 and 12 species in stations 1-3 respectively. The highest individual plants (561) were observed in station 1 while the least (87) were observed in station 3. The mean values of stations 1 and 2 were significantly and statistically different from site 3 at p<0.05. The results obtained showed some dominant species to include Elaeis guincensis, Polyaithia longifolia, Pinus spp, Gmelina arborea, Wodyetia bifareata, Citrus sinensis, Cocos nuciferia while others were the least dominant species found in the study area. The Margalef, Mehinicks and Shannon Wiener values were consistently highest in station 2 but lowest in station 3.  Human disturbances had negative impact on tree species abundance especially in site 3. It is therefore recommended that management interventions are necessary in other to stop indiscriminate felling of the various trees species that made up the different groups.

scholarly journals Tree Species Classification Using Hyperion and Sentinel-2 Data with Machine Learning in South Korea and China

2019 ◽  
Vol 8 (3) ◽  
pp. 150 ◽  
Author(s):  
Joongbin Lim ◽  
Kyoung-Min Kim ◽  
Ri Jin
Keyword(s):  
Machine Learning ◽  
Tree Species ◽  
North Korea ◽  
Training Data ◽  
Machine Learning Techniques ◽  
Species Classification ◽  
Tree Species Classification ◽  
Hyperion Data ◽  
Study Sites ◽  
Sentinel 2

Remote sensing (RS) has been used to monitor inaccessible regions. It is considered a useful technique for deriving important environmental information from inaccessible regions, especially North Korea. In this study, we aim to develop a tree species classification model based on RS and machine learning techniques, which can be utilized for classification in North Korea. Two study sites were chosen, the Korea National Arboretum (KNA) in South Korea and Mt. Baekdu (MTB; a.k.a., Mt. Changbai in Chinese) in China, located in the border area between North Korea and China, and tree species classifications were examined in both regions. As a preliminary step in developing a classification algorithm that can be applied in North Korea, common coniferous species at both study sites, Korean pine (Pinus koraiensis) and Japanese larch (Larix kaempferi), were chosen as targets for investigation. Hyperion data have been used for tree species classification due to the abundant spectral information acquired from across more than 200 spectral bands (i.e., hyperspectral satellite data). However, it is impossible to acquire recent Hyperion data because the satellite ceased operation in 2017. Recently, Sentinel-2 satellite multispectral imagery has been used in tree species classification. Thus, it is necessary to compare these two kinds of satellite data to determine the possibility of reliably classifying species. Therefore, Hyperion and Sentinel-2 data were employed, along with machine learning techniques, such as random forests (RFs) and support vector machines (SVMs), to classify tree species. Three questions were answered, showing that: (1) RF and SVM are well established in the hyperspectral imagery for tree species classification, (2) Sentinel-2 data can be used to classify tree species with RF and SVM algorithms instead of Hyperion data, and (3) training data that were built in the KNA cannot be used for the tree classification of MTB. Random forests and SVMs showed overall accuracies of 0.60 and 0.51 and kappa values of 0.20 and 0.00, respectively. Moreover, combined training data from the KNA and MTB showed high classification accuracies in both regions; RF and SVM values exhibited accuracies of 0.99 and 0.97 and kappa values of 0.98 and 0.95, respectively.

scholarly journals Impacts of Different Tree Species of Different Sizes on Spatial Distribution of Herbaceous Plants in the Nigerian Guinea Savannah Ecological Zone

Scientifica ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Toma Buba
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Open Field ◽  
Tree Species ◽  
Herbaceous Species ◽  
Ecological Zone ◽  
Vitellaria Paradoxa ◽  
Parkia Biglobosa ◽  
Species Richness And Diversity ◽  
Individual Trees

This study was aimed at finding the impacts of different tree species and individual trees of different sizes on species richness, diversity, and composition of the herbaceous layer. All the three tree species have greatly increased species richness and diversity both within and outside their crown zones compared with the open grassland. Both species richness and diversity were found to be higher under all the three tree species than outside their crowns, which was in turn higher than the open field.Daniella oliverihas the highest species richness and diversity both within and outside its crown zone followed byVitellaria paradoxaand thenParkia biglobosa. The result also revealed that the same tree species with different sizes leads to different herbaceous species richness, diversity, and composition under and around the trees’ crowns.P. biglobosaandV. paradoxatrees with smaller sizes showed higher species richness and diversity under their crowns than the bigger ones. The dissimilarity of species composition differs between the inside and outside crown zones of the individuals of the same tree species and among the different trees species and the open field.

Mixture of Triclopyr and Imazapyr More Effective than Triclopyr Alone for Hardwood Forest Stand Improvement

2020 ◽  
Author(s):  
Mark A Turner ◽  
William D Gulsby ◽  
Craig A Harper
Keyword(s):  
Coastal Plain ◽  
Tree Species ◽  
Significant Proportion ◽  
Forest Stand ◽  
Liquidambar Styraciflua ◽  
Minimal Risk ◽  
Herbicide Mixture ◽  
Soil Activity ◽  
Individual Trees ◽  
Better Than

Abstract Treatment of individual trees in hardwood stands typically is conducted with herbicides that have no soil activity, such as triclopyr. However, triclopyr is not effective on some tree species. Applying a mixture of triclopyr and imazapyr would broaden the spectrum of species controlled, but nontarget mortality may be problematic as imazapyr may affect other trees through soil activity. We applied herbicide via girdle-and-spray as part of a forest stand improvement treatment in four upland hardwood stands in the Upper Coastal Plain of Alabama. We compared effects of using triclopyr alone with a mixture of triclopyr and imazapyr 18 months posttreatment. Only one untreated sweetgum (Liquidambar styraciflua) out of 440 trees was killed in the stands treated with the herbicide mixture (0.5 percent nontarget mortality rate). Nontarget mortality did not differ between treatments. However, the herbicide mixture controlled hickory (Carya spp.) and sourwood (Oxydendrum arboreum) better than triclopyr alone, with 56 percent of hickory treated with triclopyr still alive 18 months later, compared with 0 percent of hickory treated with the mixture. Our results indicate a mixture of triclopyr and imazapyr provides better control than triclopyr alone, and there is minimal risk to nontarget tree species in hardwood stands when used according to label recommendations. Study Implications Forest stand improvement (FSI) is a noncommercial practice typically conducted by cutting and using herbicide to kill undesirable trees. Consideration must be given to herbicide selection, which is based on efficacy on target species while minimizing nontarget mortality of residual trees. We found that a mixture of triclopyr and imazapyr applied via girdle-and-spray was more effective for FSI than triclopyr alone, which failed to control a significant proportion of treated hickory, and resulted in essentially no nontarget mortality in mixed hardwood stands 18 months after application.

scholarly journals Over- and Underyielding in Time and Space in Experiments with Mixed Stands of Scots Pine and Norway Spruce

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 495 ◽  
Author(s):  
Lars Drössler ◽  
Eric Agestam ◽  
Kamil Bielak ◽  
Małgorzata Dudzinska ◽  
Julia Koricheva ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Tree Species ◽  
Mixed Forest ◽  
Stand Age ◽  
Mixed Species ◽  
Mixed Stands ◽  
Mixing Effect ◽  
Individual Site ◽  
Study Sites

Pine-spruce forests are one of the commonest mixed forest types in Europe and both tree species are very important for wood supply. This study summarized nine European studies with Scots pine and Norway spruce where a mixed-species stand and both monocultures were located in an experimental set-up. Overyielding (where growth of a mixed stand was greater than the average of both monocultures) was relatively common and often ranged between 0% and 30%, but could also be negative at individual study sites. Each individual site demonstrated consistent patterns of the mixing effect over different measurement periods. Transgressive overyielding (where the mixed-species stand was more productive than either of the monocultures) was found at three study sites, while a monoculture was more productive on the other sites. Large variation between study sites indicated that the existing experiments do not fully represent the extensive region where this mixed pine-spruce forest can occur. Pooled increment data displayed a negative influence of latitude and stand age on the mixing effect of those tree species in forests younger than 70 years.

Tree Species Selection by Free-Ranging Koala Populations in Victoria.

1985 ◽  
Vol 12 (2) ◽  
pp. 137 ◽  
Author(s):  
MA Hindell ◽  
KA Handasyde ◽  
AK Lee
Keyword(s):  
Tree Species ◽  
Species Selection ◽  
Phascolarctos Cinereus ◽  
Individual Trees ◽  
Free Ranging

Tree species selection was studied in free-ranging populations of koalas [Phascolarctos cinereus] on Phillip Island and the Brisbane Ranges in Victoria. At both sites koalas were found mainly on Eucalyptus spp. but occasionally used Acacia spp. Although koalas occurred on most of the Eucalyptus spp. present, both populations showed preferences for one or two species, particularly E. viminalis. Individual koalas showed different preferences, but the majority preferred E. viminalis. Some occurred exclusively on other species even when E. viminalis was close by. Koalas also showed preference for individual trees within a species.

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