scholarly journals Bark-stripping of common buckthorn by goats during managed browsing on bur oak savannas

2021 ◽  
Author(s):  
Neal D. Mundahl ◽  
Ryan Walsh
Keyword(s):  
Bark Stripping ◽  
Oak Savannas ◽  
Bur Oak

scholarly journals Bark-stripping of Common Buckthorn by Goats During Managed Browsing on Bur Oak Savannas

2021 ◽  
Author(s):  
Neal Mundahl ◽  
Ryan Walsh
Keyword(s):  
Invasive Plants ◽  
Cumulative Effects ◽  
Selective Feeding ◽  
Bark Stripping ◽  
Large Seed ◽  
Oak Savannas ◽  
Bur Oak

Abstract Goats are being used increasingly to manage woody invasive plants in woodland habitats, but their specific impacts on those plants over a period of time during active, periodic browsing has not been documented. This study investigated bark-stripping by goats browsing on common buckthorn in savanna habitats, focusing on possible size-selective feeding and the cumulative effects of repeated, periodic browsing over a 3-year period. When surveyed after the first browsing period, bark was stripped selectively on buckthorn stems 20 to 60 mm in diameter. Approximately 60% of all stripped stems were completely girdled, but only 14-17% of stems were bark-stripped. After five browsing periods, 66% of standing stems displayed bark stripping and 39% were completely girdled. Buckthorn densities were reduced by 90% compared to the first browsing period, the decline resulting mostly from consumption of foliage and terminal shoots of small (<20 mm) buckthorn and bark-stripping resulting in top-kill in intermediate-sized (20-60 mm) plants. Large buckthorn (>60 mm) were largely unimpacted by goats. Relatively few (28%) seedling buckthorn were browsed by goats, although >90% of 2nd-year plants were browsed. Buckthorn can be managed in part via goat browsing, but repeated, periodic browsing over several to many years may be necessary to produce a significant impact, and other techniques will be needed to eliminate large, seed-producing plants.

Modelling the susceptibility of pine stands to bark stripping by Chacma baboons (Papio ursinus) in the Mpumalanga Province of South Africa

2017 ◽  
Vol 44 (4) ◽  
pp. 298 ◽  
Author(s):  
Ilaria Germishuizen ◽  
Kabir Peerbhay ◽  
Riyad Ismail
Keyword(s):  
South Africa ◽  
Random Forests ◽  
Risk Evaluation ◽  
Site Index ◽  
Pine Plantations ◽  
Bark Stripping ◽  
Papio Ursinus ◽  
Mpumalanga Province ◽  
Chacma Baboons ◽  
Pinus Spp

Context Commercial pine (Pinus spp.) plantations in southern Africa have been subjected to bark stripping by Chacma baboons (Papio ursinus) for many decades, resulting in severe financial losses to producers. The drivers of this behaviour are not fully understood and have been partially attributed to resource distribution and availability. Aims The study sought to develop a spatially explicit ecological-risk model for bark stripping by baboons to understand the environmental factors associated with the presence of damage in the pine plantations of the Mpumalanga province of South Africa. Methods The model was developed in Random Forests, a machine learning algorithm. Baboon damage information was collected through systematic surveys of forest plantations conducted annually. Environmental predictors included aspects of climate, topography and compartment-specific attributes. The model was applied to the pine plantations of the study area for risk evaluation. Key results The Random Forests classifier was successful in predicting damage occurrence (F1 score=0.84, area under curve (AUC)=0.96). Variable predictors that contributed most to the model classification accuracy were related to pine-stand characteristics, with the age of trees being the most important predictor, followed by species, site index and altitude. Variables pertaining to the environment surrounding a pine stand did not contribute substantially to the model performance. Key conclusions (1) The study suggests that bark stripping is influenced by compartment attributes; (2) predicted risk of bark stripping is higher in stands above the age of 5 years planted on high-productivity forestry sites, where site index (SI) is above 25; (3) presence of damage is not related to the proximity to natural areas; (4) further studies are required to investigate ecological and behavioural patterns associated with bark stripping. Implications The model provides a tool for understanding the potential extent of the risk of bark stripping by baboons within this region and it can be applied to other forestry areas in South Africa for risk evaluation. It contributes towards the assessment of natural hazards potentially affecting pine plantations and supports the development of risk-management strategies by forest managers. The model highlights opportunities for cultural interventions that may be tested for damage control.

Climate sensitivity of wood-anatomical features in a ring-porous oak (Quercusmacrocarpa)

1989 ◽  
Vol 19 (5) ◽  
pp. 639-644 ◽  
Author(s):  
D. W. Woodcock
Keyword(s):  
Climate Sensitivity ◽  
Ring Width ◽  
Vessel Diameter ◽  
Regression Equation ◽  
Vessel Density ◽  
Anatomical Features ◽  
Late Wood ◽  
Precipitation Characteristics ◽  
Bur Oak ◽  
Anatomical Characters

Anatomical characters of the early- and late-wood of individuals of a ring-porous oak (bur oak, Quercusmacrocarpa Michx.) growing in southeastern Nebraska display sensitivity to yearly variations in precipitation. Characteristics of the latewood increment (latewood vessel diameter and density) are closely related to ring width, with vessel diameter varying directly and vessel density varying inversely with ring width. Various analyses indicate that ring width appears to be a less direct climatic indicator than latewood vessel diameter in these trees. A regression equation incorporating latewood vessel diameter is used successfully to reconstruct precipitation over a 9-month period (October–June).

scholarly journals Afforested farmland vs. forestland: Effects of bark stripping by Cervus elaphus and climate on production potential and structure of Picea abies forests

PLoS ONE ◽  
2019 ◽  
Vol 14 (8) ◽  
pp. e0221082 ◽  
Author(s):  
Jan Cukor ◽  
Zdeněk Vacek ◽  
Rostislav Linda ◽  
Ram Prasad Sharma ◽  
Stanislav Vacek
Keyword(s):  
Picea Abies ◽  
Cervus Elaphus ◽  
Production Potential ◽  
Bark Stripping

scholarly journals Susceptibility of pine stands to bark stripping by chacma baboons Papio ursinus in the Eastern Highlands of Zimbabwe

2009 ◽  
Vol 55 (6) ◽  
pp. 389-395 ◽  
Author(s):  
C.A.T. Katsvanga ◽  
L. Jimu ◽  
J.F. Mupangwa ◽  
D. Zinner
Keyword(s):  
Rainy Season ◽  
Predictor Variables ◽  
Bark Stripping ◽  
Conservation Areas ◽  
Papio Ursinus ◽  
Crop Fields ◽  
Pine Trees ◽  
Chacma Baboons ◽  
Level Of Significance ◽  
Eastern Highlands

Abstract The aim of this study was to determine the susceptibility, intensity and distribution of pine trees to bark stripping by chacma baboons Papio ursinus in three plantations in the Eastern Highlands of Zimbabwe. The number of plots/ha, stripped trees/plot and stripped trees/ha was recorded during the pre-rainy, rainy and post-rainy seasons from August 2006 to May 2007. During data collection, altitude, aspect, season and other site predictor variables (e.g., roads and fire traces, water points, indigenous vegetation conservation areas, crop fields, human settlements, wattle scrubs, rocky areas, open grasslands, earlier stripped sites and roost sites) were recorded for each plot in association with selected predictor variables within plantation estates. Data on the number of stripped plots/ha, stripped trees/plot and stripped trees/ha were analysed as dependent variables using the Generalised linear Model (GLM) through SPSS version 15 (2006) to determine which predictor variables were significantly related to bark stripping. Differences between means were tested using Bonferroni tests with a 5% level of significance. Our findings show that bark stripping of pine trees by baboons occurred at all altitudes and aspects. Overall, the number of bark stripped trees/ha did not significantly vary by season. The number of bark stripped plots/ha was lower during the pre-rainy season than the rainy season, whereas the number of bark stripped trees/plot was higher during the pre-rainy than the rainy season. Bark stripping of pines occurred more often in the vicinities of areas with abundant food and water.

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