Determinants of Chinese and European Privet (Ligustrum sinense and Ligustrum vulgare) Invasion and Likelihood of Further Invasion in Southern U.S. Forestlands

2012 ◽  
Vol 5 (4) ◽  
pp. 454-463 ◽  
Author(s):  
Hsiao-Hsuan Wang ◽  
William E. Grant

AbstractChinese and European privets are among the most aggressive invasive shrubs in forestlands of the southern United States. We analyzed extensive field data collected by the U.S. Forest Service covering 12 states to identify potential determinants of invasion and to predict likelihood of further invasion under a variety of possible management strategies. Results of multiple logistic regression, which classified 75% of the field plots correctly with regard to species presence and absence, indicated probability of invasion is correlated positively with elevation, adjacency (within 300 m) to waterbodies, mean extreme maximum temperature, site productivity, species diversity, natural regeneration, wind disturbance, animal disturbance, and private land ownership and is correlated negatively with slope, stand age, site preparation, artificial regeneration, distance to the nearest road, fire disturbance, and public land ownership. Habitats most at risk to further invasion (likelihood of invasion > 10%) under current conditions occur throughout Mississippi, with a band stretching eastward across south-central Alabama, and in eastern Texas and western Louisiana. Invasion likelihoods could be reduced most by conversion to public land ownership, followed by site preparation, fire disturbance, artificial regeneration, and elimination of animal disturbance. While conversion of land ownership may be neither feasible nor desirable, this result emphasizes the opportunity for reducing the likelihood of invasions on private lands via increased use of selected management practices.

2021 ◽  
Vol 13 (15) ◽  
pp. 8460
Author(s):  
Armel Rouamba ◽  
Hussein Shimelis ◽  
Inoussa Drabo ◽  
Mark Laing ◽  
Prakash Gangashetty ◽  
...  

Pearl millet (Pennisetum glaucum) is a staple food crop in Burkina Faso that is widely grown in the Sahelian and Sudano-Sahelian zones, characterised by poor soil conditions and erratic rainfall, and high temperatures. The objective of this study was to document farmers’ perceptions of the prevailing constraints affecting pearl millet production and related approaches to manage the parasitic weeds S. hermonthica. The study was conducted in the Sahel, Sudano-Sahelian zones in the North, North Central, West Central, Central Plateau, and South Central of Burkina Faso. Data were collected through a structured questionnaire and focus group discussions involving 492 participant farmers. Recurrent drought, S. hermonthica infestation, shortage of labour, lack of fertilisers, lack of cash, and the use of low-yielding varieties were the main challenges hindering pearl millet production in the study areas. The majority of the respondents (40%) ranked S. hermonthica infestation as the primary constraint affecting pearl millet production. Respondent farmers reported yield losses of up to 80% due to S. hermonthica infestation. 61.4% of the respondents in the study areas had achieved a mean pearl millet yields of <1 t/ha. Poor access and the high cost of introduced seed, and a lack of farmers preferred traits in the existing introduced pearl millet varieties were the main reasons for their low adoption, as reported by 32% of respondents. S. hermonthica management options in pearl millet production fields included moisture conservation using terraces, manual hoeing, hand weeding, use of microplots locally referred to as ‘zaï’, crop rotation and mulching. These management techniques were ineffective because they do not suppress the below ground S. hermonthica seed, and they are difficult to implement. Integrated management practices employing breeding for S. hermonthica resistant varieties with the aforementioned control measures could offer a sustainable solution for S. hermonthica management and improved pearl millet productivity in Burkina Faso.


2021 ◽  
Vol 2 ◽  
Author(s):  
Estelle Levetin

Climate change is having a significant effect on many allergenic plants resulting in increased pollen production and shifts in plant phenology. Although these effects have been well-studied in some areas of the world, few studies have focused on long-term changes in allergenic pollen in the South Central United States. This study examined airborne pollen, temperature, and precipitation in Tulsa, Oklahoma over 25 to 34 years. Pollen was monitored with a Hirst-type spore trap on the roof of a building at the University of Tulsa and meteorology data were obtained from the National Weather Service. Changes in total pollen intensity were examined along with detailed analyses of the eight most abundant pollen types in the Tulsa atmosphere. In addition to pollen intensity, changes in pollen season start date, end date, peak date and season duration were also analyzed. Results show a trend to increasing temperatures with a significant increase in annual maximum temperature. There was a non-significant trend toward increasing total pollen and a significant increase in tree pollen over time. Several individual taxa showed significant increases in pollen intensity over the study period including spring Cupressaceae and Quercus pollen, while Ambrosia pollen showed a significant decrease. Data from the current study also indicated that the pollen season started earlier for spring pollinating trees and Poaceae. Significant correlations with preseason temperature may explain the earlier pollen season start dates along with a trend toward increasing March temperatures. More research is needed to understand the global impact of climate change on allergenic species, especially from other regions that have not been studied.


2017 ◽  
Vol 47 (8) ◽  
pp. 1123-1130 ◽  
Author(s):  
Pontus M.F. Lindgren ◽  
Thomas P. Sullivan ◽  
Douglas B. Ransome ◽  
Druscilla S. Sullivan ◽  
Lisa Zabek

Integration of trees with forage and livestock production as silvopastoralism is another potential component of intensive forest management. Stand thinning and fertilization may enhance growth of crop trees and understory forage for livestock. We tested the hypothesis that large-scale precommercial thinning (PCT) (particularly heavy thinning to ≤1000 stems·ha−1) and repeated fertilization, up to 20 years after the onset of treatments, would enhance production of graminoids, forbs, and shrubs as cattle (Bos taurus L.) forage. Results are from two long-term studies: (1) PCT (1988–2013) and (2) PCT with fertilization (PCT–FERT) (1993–2013) of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands in south-central British Columbia, Canada. Mean biomass estimates of graminoids, forbs, total herbs, and shrubs were not affected by stand density. However, fertilization enhanced mean biomass estimates of graminoids, forbs, and total herbs, but not shrubs. Thus, the density part of our hypothesis was not supported, but the nutrient addition part was supported at least for the herbaceous components. Biomass of the herbaceous understory was maintained as a silvopasture component for up to 20 years (stand age 13 to 33 years) in fertilized heavily thinned stands prior to canopy closure.


1990 ◽  
Vol 14 (2) ◽  
pp. 59-63
Author(s):  
William H. McWilliams

Abstract Commercial harvests were carried out on 36% of the pine-site timberland in six states of the south-central United States during the interval of time between the last two forest inventories of each state. Half of forest industry's pine-site timberland was harvested, compared with 30% for nonindustrial private owners. Fifty-four percent of the heavily cut pine stands were at least 60% stocked with pine following harvest. The overall rate of replacement for pine stands was 78%. South. J. Appl. For. 14(2):59-63.


2010 ◽  
Vol 25 (3) ◽  
pp. 127-135
Author(s):  
Wendy Arjo

Abstract Timber resources are a vital part of the economy in the Pacific Northwest, yet reforestation efforts are often hampered by animal damage. Understanding the factors that influence seedling damage can assist managers in implementing appropriate techniques to reduce species-specific damage. I radio-collared and monitored mountain beavers (Aplodontia rufa) from preharvest to seedling planting to determine the impacts of forest management practices on demographics. In addition, I monitored Douglas-fir (Pseudotsuga menziesii) seedlings on 28 plots on two harvest units (Vesta and Schoolhouse) to determine the effects of chemical site preparation on mountain beaver foraging and subsequent seedling damage. Mountain beaver densities differed between silvicultural treatments (F3,39 = 3.58, P < 0.02), although reproductive success did not (χ2 = 0.14, df = 1, P = 0.70). Larger mountain beaver home ranges were documented in the mature timber compared with those following harvest. Home ranges were also larger in the chemical site preparation portion of the unit (mean = 3.37 ± 0.9 ha) than in the nontreated portion of the unit (mean = 0.82 ± 0.17 ha) on Vesta. Herbicide treatment did not promote seedling damage on either unit. Vegetation does not appear to be the only factor influencing mountain beaver movements and seedling damage. Availability of water is very important for mountain beavers and may also influence their foraging choice, as well as contributing to their increased movements in mature timber (reduced groundwater) versus clearcut areas. Understanding the effects of vegetation on population demographics and subsequent seedling damage may allow for initiating a nonlethal management method using alternative forage.


1962 ◽  
Vol 22 (4) ◽  
pp. 445-460 ◽  
Author(s):  
Theodore Saloutos

If by land policy we mean a comprehensive, well-thought-out plan that made for an efficient long-range use of our agricultural resources, we are reasonably safe in saying we had none. If we had anything that came close to resembling a policy, it was that of throwing open vast quantities of public and private lands to cultivation which resulted in maladjustments that made it difficult, if not impossible, for many farmers to adjust themselves to capitalistic methods of production and distribution. The extent of these maladjustments may be gauged in part by observing the status of agriculture on the eve of the New Deal. Shrinking foreign markets, world-wide competition, rising tariff walls, poor farm management practices, and excessive production and distribution costs were accompanied by sharp increases in indebtedness, farm foreclosures, and tenancy. Agriculture was receiving a dwindling share of the national income, capital formation was being discouraged, and farming had been relegated to a subordinate position within the economy.


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