Forty years of alternative management practices in second-growth, pole-size northern hardwoods. I. Tree quality deveSopment

1995 ◽  
Vol 25 (7) ◽  
pp. 1173-1179 ◽  
Author(s):  
Terry F. Strong ◽  
Gayne G. Erdmann ◽  
Jeffrey N. Niese

The effects of six cutting methods on tree quality were observed for 20 years in a northern hardwood stand in Wisconsin. Cutting treatments included an uncut control, three levels of individual tree selection (heavy, medium, and light), crop tree release, and diameter limit. Average annual diameter growth was least in the control treatment (0.13 in./year, 0.33 cm/year) and greatest in the heavy individual tree selection and diameter-limit cuts (0.18 in./year, 0.46 cm/year). Cull in trees in 1992 was significantly higher in the control and diameter-limit treatments. Changes in merchantable height (number of 16-ft (4.9-m) logs) over the period were not significantly different among treatments, but average merchantable heights were significantly greater in the individual tree selection treatments in 1992. Average tree grade increases were significantly better in the medium selection plots than in all other treatments except the crop tree release. Nearly a third of the sawlog-size trees in both the control and diameter-limit treatments were below sawlog grade, significantly more than in the other treatments. Only 2% of the trees in the heavy selection plots were below grade. Tree quality improved the most overall in the medium selection plots. Stand structure in this treatment also most closely matched that recommended by guides developed to sustain yield over long periods of cutting under uneven-aged management.

1995 ◽  
Vol 25 (7) ◽  
pp. 1180-1188 ◽  
Author(s):  
Jeffrey N. Niese ◽  
Terry F. Strong ◽  
Gayne G. Erdmann

Potential economic returns to tree quality were analyzed for four uneven-aged cutting treatments and a control in a Wisconsin northern hardwood stand. The economics of tree quality changes were analyzed over a 20-year period (1971–1992), using a marginal analysis that included tree grade, lumber volume yields, reported lumber values, and hardwood management costs. Net present values were highest for the heavy individual tree selection (60 ft"/acre, 13.8 m2/ha) treatment, and residual tree quality improved significantly. The medium selection (75 ft2/acre, 17.3 m2/ha) treatment had the greatest improvement in tree quality as well as high economic returns. The light selection (90 ft2/acre, 20.7 m2/ha) treatment had the highest residual stand value, but low harvest revenues. An 8-in. (20.3-cm) diameter-limit treatment had the lowest economic returns and the poorest tree quality.


2005 ◽  
Vol 20 (3) ◽  
pp. 160-166 ◽  
Author(s):  
Wayne D. Johnstone

Abstract The effects of spacing 7-year-old second-growth lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) are reported 20 growing seasons after treatment. Five spacing levels of 500, 1,000, 1,500, 2,000, and 2,500 trees per hectare, plus unspaced controls, were established on plots in central British Columbia. Both individual-tree and per-hectare data were analyzed. Spacing had a significant effect on all of the individual-tree characteristics examined, but its effect on per-hectare values was mixed. Although this report only provides short-term information on the effects of juvenile spacing on the growth and yield of lodgepole pine, it does indicate the need to optimize individual-tree growth rates with levels of growing stock to maximize yield per unit area. West. J. Appl. For. 20(3):160–166.


HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 661-666 ◽  
Author(s):  
Jennifer L. Emerson ◽  
John Frampton ◽  
Steven E. McKeand

A series of open-pollinated progeny tests of Fraser fir [Abies fraseri (Pursh) Poir.] was analyzed to determine natural variation among six geographic seed sources and to estimate genetic parameters for traits important in Christmas tree production. Highly significant differences were found among seed sources and families within sources (P ≤ 0.0001) for height after 4 years in the field. The individual-tree within-population heritability values for the traits measured in Year 4 ranged from 0 to 0.44, with height having the highest heritability, overall tree quality having a heritability of 0.14, and bud and branching traits having varying heritabilities. Heritability values for height at age 4 varied greatly among the six sources, from 0.15 for the Black Mountains to 0.67 for the Great Smoky Mountains. Highly significant seed source × site interactions as well as family within source × site interactions existed for height. Stability variance analysis, after removing the environmental heterogeneity, showed significant instability across the test sites for two of the six seed sources for height after 4 years, and some rank changes occurred. The high heritability values for height indicate that economically important genetic gains can be made in Fraser fir for Christmas tree production because of the importance of height in determining Christmas tree value.


2000 ◽  
Vol 17 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Paul E. Sendak ◽  
William B. Leak ◽  
Wanda B. Rice

Abstract Few studies in New England have related timber cutting in northern hardwood stands to improvements in timber quality. The objective of this study was to assess tree-quality improvement for lumber production from initial cutting in a northern hardwood forest on the Bartlett Experimental Forest in New Hampshire that occurred about 40 yr ago. This study used nine compartments on the Forest that were initially cut in the 1950s. Cutting methods included three diameter-limit cuts and six individual tree selection cuts followed by timber stand improvement by chemical girdling.The nine compartments remained undisturbed by cutting for approximately 40 yr. By 1996, average tree grade had improved in all compartments, from 3.8 to 3.1 for the diameter limits combined and from 3.2 to 2.7 for the selection compartments combined. Returns per acre of standing inventory were influenced by tree quality but also were confounded with compartment volume and species mix. In general, return of standing inventory in 1996, whether per acre or per mbf, was greater in the selection compartments, but one of the diameter limits had a significant volume of high value red oak timber that skewed its total value upward. North. J. Appl. For. 17(1):9-15.


2021 ◽  
Author(s):  
Jan Komárek ◽  
Petr Klápště ◽  
Karel Hrach ◽  
Tomáš Klouček

Abstract With the ever-improving Earth observation capabilities, variables such as tree health status, biomass storage, or stand structure are increasingly estimated through remote sensing. While many protocols of data acquisition and satellite data processing are in place, the still novel unmanned aerial vehicles (UAVs) face some challenges during data acquisition and processing. While tree height extraction seems to be a common practice, identifying individual trees and measuring their crowns is still quite tricky. We performed several flights with three different UAVs and four different popular sensors over two sites with coniferous forests of various ages at flight levels of 100–200 m above ground level (AGL) using custom settings preset by UAV solution suppliers. Considering the success rate of the individual tree identification, casual RGB cameras provided more consistent results at all flight levels (84 − 77% for Phantom 4), while the success of tree identification decreases with higher flight levels and smaller crowns in the case of multispectral cameras (77 − 54% for RedEdge-M). In general, RGB cameras yielded the best results at 150 m AGL while multispectral cameras at 100 m AGL. Regarding the accuracy of the measured crown diameters, most datasets tended to overestimate when using automatic crown delineation within the lidR package. Only RGB cameras yielded satisfactory results (Mean Absolute Error – MAE of 0.79–0.99 m and 0.88–1.16 m for Phantom 4 and Zenmuse X5S, respectively). Multispectral cameras overestimated more than RGB cameras, especially in the full-grown forest (MAE = 1.26–1.77 m); on the other hand, they offered, in addition to the structural, also spectral information. We conclude that widespread ready-made solutions mounted with low-cost RGB cameras yield very satisfactory results for describing the structural forest information at 150 m AGL. When (multi)spectral information is needed, we recommend reducing the flight level to 100 m AGL to acquire sufficient structural forest information.


2012 ◽  
Vol 42 (6) ◽  
pp. 1115-1125 ◽  
Author(s):  
Chris Gronewold ◽  
Anthony W. D’Amato ◽  
Brian J. Palik

An understanding of long-term growth dynamics is central to the development of sustainable uneven-aged silvicultural systems for northern hardwood forests in eastern North America. Of particular importance are quantitative assessments of the relationships between stocking control and long-term growth and quality development. This study examined these relationships in a long-term silviculture experiment established in northern hardwood stands in the Upper Peninsula of Michigan, USA. Stands were old growth at the onset of the experiment and were maintained at three residual stocking levels (11.5, 16.1, and 20.7 m2·ha–1) over a 57-year period. Several aspects of long-term stocking control were evaluated, including the effects of residual stocking on tree quality development and the relationships between stand stocking and individual tree growth and stand-level production. Results suggest that residual stocking had little impact on quality development, likely due to the initial old-growth condition of the stands examined. In contrast, our results indicate that a range of stand densities will maintain acceptable rates of stand-level production in selection systems and that growth can be shifted between diameter classes depending on desired future stand conditions.


2017 ◽  
Vol 168 (3) ◽  
pp. 127-133
Author(s):  
Matthew Parkan

Airborne LiDAR data: relevance of visual interpretation for forestry Airborne LiDAR surveys are particularly well adapted to map, study and manage large forest extents. Products derived from this technology are increasingly used by managers to establish a general diagnosis of the condition of forests. Less common is the use of these products to conduct detailed analyses on small areas; for example creating detailed reference maps like inventories or timber marking to support field operations. In this context, the use of direct visual interpretation is interesting, because it is much easier to implement than automatic algorithms and allows a quick and reliable identification of zonal (e.g. forest edge, deciduous/persistent ratio), structural (stratification) and point (e.g. tree/stem position and height) features. This article examines three important points which determine the relevance of visual interpretation: acquisition parameters, interactive representation and identification of forest characteristics. It is shown that the use of thematic color maps within interactive 3D point cloud and/or cross-sections makes it possible to establish (for all strata) detailed and accurate maps of a parcel at the individual tree scale.


2021 ◽  
Vol 6 (2) ◽  
pp. 84
Author(s):  
Dyah Ayu Widiasih ◽  
Johanna Frida Lindahl ◽  
Wayan T. Artama ◽  
Adi Heru Sutomo ◽  
Pande Made Kutanegara ◽  
...  

Leptospirosis is a zoonotic disease occurring worldwide with reproductive symptoms and production losses in livestock, while humans can suffer fatal renal failure. In Yogyakarta Special Province, Indonesia, there have been several outbreaks with high case fatality, demonstrating the public health importance, but there is limited understanding of the epidemiology. This study used an EcoHealth approach to ensure transdisciplinarity and community participation. Seroprevalence of Leptospira in animals was studied between October 2011 and May 2013 in 15 villages. Serum samples from 1404 cattle and 60 small ruminants were screened by a Microscopic Agglutination Test (MAT), first in pools, and then the individual positive samples were identified. Focus group discussions including farmers, village officials, and official stakeholders were used to explore knowledge and behavior of zoonotic diseases, particularly leptospirosis. Two small ruminants were seropositive for Leptospira icterohemorrhagiae. From the cattle, 3.7% were seropositive, and the most common serovars were Leptospira hardjo, followed by L. icterohemorrhagiae. Out of all farms, 5.6% had at least one positive cattle. Risk factor analyses showed that the risk of the farm being seropositive increased if the farmer used water from an open source, or if farming was not the main occupation. This study showed the presence of Leptospira spp. in ruminants in Yogyakarta and identified use of open water as a risk factor for the livestock. We also observed that the knowledge related to leptospirosis was low, and risky farm management practices were commonly employed.


2021 ◽  
Vol 13 (10) ◽  
pp. 5445
Author(s):  
Muyun Sun ◽  
Jigan Wang ◽  
Ting Wen

Creativity is the key to obtaining and maintaining competitiveness of modern organizations, and it has attracted much attention from academic circles and management practices. Shared leadership is believed to effectively influence team output. However, research on the impact of individual creativity is still in its infancy. This study adopts the qualitative comparative analysis method, taking 1584 individuals as the research objects, underpinned by a questionnaire-based survey. It investigates the influence of the team’s shared leadership network elements and organizational environmental factors on the individual creativity. We have found that there are six combination of conditions of shared leadership and organizational environmental factors constituting sufficient combination of conditions to increase or decrease individual creativity. Moreover, we have noticed that the low network density of shared leadership is a sufficient and necessary condition of reducing individual creativity. Our results also provide management suggestions for practical activities during the team management.


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