scholarly journals Woody Encroachment Extent and Its Associated Impacts on Plant and Herbivore Species Occurrence in Maswa Game Reserve, Tanzania

2019 ◽  
Vol 9 (3) ◽  
pp. 63 ◽  
Author(s):  
Houssein Samwel Kimaro ◽  
Ayoub M. Asenga ◽  
Linus Munishi ◽  
Anna C. Treydte
Keyword(s):  
Structural Changes ◽  
Woody Plant ◽  
Plant Cover ◽  
Fire Regimes ◽  
Management Tool ◽  
Herbaceous Plant ◽  
Woody Plant Encroachment ◽  
Species Occurrence ◽  
Game Reserve ◽  
Herbivore Species

Habitat degradation caused by woody plant encroachment has been a common phenomenon in savanna ecosystems. An increasing woody plant cover in open grassland reduces grazing grounds and, consecutively, impacts mammalian herbivores, but structural changes and their associated impact have rarely been assessed and quantified. We analyzed the extent of woody plant encroachment via remote sensing and used transects and plots to assess encroaching woody plant species and their associated impacts on herbaceous plant and herbivore species in Maswa Game Reserve, Tanzania. We found that woody plant cover had increased by 0.5% to 2.6% per annum over the last thirty years, while in other parts of the park it has decreased by 0.5% to 1.5% per annum. Acacia drepanolobium was the dominant encroaching woody species, and the number of stems in heavily encroached sites was seven times and three times higher than in open grassland and at medium encroached sites, respectively. In encroached plots, grazer and mixed feeder species occurrence were reduced while the presence of browser species was slightly elevated. Furthermore, our finding shows that bare ground cover is positively correlated with an increase of woody plant cover. Additionally, the number of herbaceous species slightly increased with the increase of woody plant encroachment, while the herbaceous cover was negatively correlated with the increase of woody plant cover. We suggest that fire regimes should be taken up to suppress the ongoing encroachment processes while strongly encroached sites might need mechanical intervention to control dense vegetation. This emphasis is on fire, particularly prescribed fire as a management tool of vegetation in Savanna ecosystem. We conclude that, woody plant encroachment is driven by different factors such as fire, mega-herbivores and topology that may interactively trigger woody plant encroachment in Savanna ecosystem.

scholarly journals Woody Plant Encroachment Impacts on Groundwater Recharge: A Review

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1466 ◽  
Author(s):  
Bharat Acharya ◽  
Gehendra Kharel ◽  
Chris Zou ◽  
Bradford Wilcox ◽  
Todd Halihan
Keyword(s):  
Water Resources ◽  
Groundwater Recharge ◽  
Woody Plant ◽  
Groundwater Resources ◽  
Plant Cover ◽  
Experimental Studies ◽  
Estimation Methods ◽  
Woody Plant Encroachment ◽  
Plant Removal ◽  
The Impact

Woody plant encroachment has profound impacts on the sustainable management of water resources in water-limited ecosystems. However, our understanding of the effects of this global phenomenon on groundwater recharge at local and regional scales is limited. Here, we reviewed studies related to (i) recharge estimation methods; (ii) mechanisms by which woody plants impact groundwater recharge; (iii) impacts of woody plant on recharge across different soil and geology; (iv) hydrological repercussions of woody plant removal; and (v) research gaps and needs for groundwater studies. We identified six different methods: water balance, water table, isotopes, chloride mass balance, electrical geophysical imaging, and modeling were used to study the impact of woody encroachment on groundwater. Woody plant encroachment could alter soil infiltration rates, soil water storage, transpiration, interception, and subsurface pathways to affect groundwater recharge. The impact is highly variable, with the extent and the magnitude varying across the soil, substrate, plant cover, and topographic locations. Our review revealed mixed effects of woody plant removal on groundwater recharge. Studies of litter interception, root water uptake, soil moisture dynamics, and deep percolation along with the progression of woody plant encroachment are still limited, warranting further experimental studies focusing on groundwater recharge. Overall, information about woody plant encroachment impacts on groundwater resources across a range of scales is essential for long-range planning of water resources.

scholarly journals Factors Influencing County Commissioners’ Decisions about Burn Bans in the Southern Plains, USA

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 686
Author(s):  
Thomas W. McDaniel ◽  
Carissa L. Wonkka ◽  
Morgan L. Treadwell ◽  
Urs P. Kreuter
Keyword(s):  
Prescribed Fire ◽  
Woody Plant ◽  
Emergency Services ◽  
Primary Sources ◽  
Management Tool ◽  
Fire Departments ◽  
Woody Plant Encroachment ◽  
Southern Plains ◽  
County Commissioners ◽  
Local Officials

Woody plant encroachment in North American rangelands has led to calls for greater use of prescribed fire to reduce fuel loads and restore grazing productivity and grassland biodiversity. However, the use of prescribed fire during periods when woody plant mortality is maximized has often been limited by temporary restrictions on outdoor burning enacted by regional or local governmental entities. This study reports the results of a survey assessing the familiarity with and attitudes toward prescribed fire in Texas and Oklahoma, USA, of officials tasked with implementing restrictions on outdoor burning and how these attitudes influence their decisions. Most responding officials considered prescribed fire to be a safe and beneficial land management tool that should be used more frequently. Self-reported familiarity with prescribed fire was the most significant explanatory variable for this attitude. Further, familiarity with prescribed fire was influenced by respondent participation in or being invited to participate in a prescribed fire. Such invitations came mostly from private landowners. Landowners wishing to use prescribed fire may benefit from building trust with local officials by demonstrating they are qualified to conduct such fires safely. This could help reduce the frequency of burn restrictions and may increase the likelihood that officials will grant burn ban exemptions to qualified burn managers. Additionally, because officials’ primary sources of prescribed fire information were reported to be local fire departments and emergency services, educating those entities about the benefits of prescribed fire for reducing wildfire risks could help reduce pressure on officials to enact or maintain burning restrictions. These findings highlight opportunities for reducing the frequency of burning restrictions, increasing opportunities for land managers to effectively halt or reverse woody plant encroachment.

Vegetation changes in the Hluhluwe-Umfolozi Game Reserve Complex from 1937 to 1975

Bothalia ◽  
1983 ◽  
Vol 14 (2) ◽  
pp. 265-269 ◽  
Author(s):  
H. K. Watson ◽  
I. A. W. Macdonald
Keyword(s):  
Structural Changes ◽  
Woody Plant ◽  
Progressive Increase ◽  
Aerial Photographs ◽  
Short Term ◽  
Tall Grass ◽  
Controlled Burning ◽  
Game Reserve ◽  
Plant Removal

The structural changes that have occurred in the vegetation of the Hluhluwe-Umfolozi Game Reserve Complex have been quantified using 1937, 1960 and 1975 aerial photographs, and related to the management history. A progressive increase in both tree and shrub cover has occurred. In the short term, both intensive woody plant removal operations and controlled burning applications appear to be effective in retarding the rate of encroachment by shrubs and trees. However, neither was effective in the long term. Significant reductions in tall grass cover attributed to sustained overgrazing have occurred.

Conservation and Restoration of Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Community Assembly ◽  
Woody Plants ◽  
Woody Plant ◽  
Priority Effects ◽  
Woody Plant Encroachment ◽  
Humpty Dumpty ◽  
Alternate States ◽  
Density And Biomass ◽  
Acid Test ◽  
Stocking Rates

Conservation programs alter herbivore stocking rates and find and protect the remaining areas that have not been plowed or converted to crops. Restoration is an ‘Acid Test’ for ecology. If we fully understand how grassland systems function and assemble after disturbance, then it should be easy to restore them after they have been degraded or destroyed. Alternatively, the idea that restorations will not be equivalent to remnants has been termed the ‘Humpty Dumpty’ hypothesis—once lost, it cannot be put back together again. Community assembly may follow rules, and if these rules are uncovered, then we may be able to accurately predict final species composition after assembly. Priority effects are sometimes found depending on species arrival orders, and they can result in alternate states. Woody plant encroachment is the increase in density and biomass of woody plants, and it is strongly affecting grassland C and water cycles.

scholarly journals Post-fire management and recovery of a pine forest in Greece

Web Ecology ◽  
2010 ◽  
Vol 10 (1) ◽  
pp. 27-31 ◽  
Author(s):  
I. Spanos ◽  
Y. Raftoyannis ◽  
P. Platis ◽  
E. Xanthopoulou
Keyword(s):  
Woody Plant ◽  
Pinus Halepensis ◽  
Plant Cover ◽  
Woody Species ◽  
Control Site ◽  
Plant Composition ◽  
Northern Greece ◽  
Pine Regeneration ◽  
Negative Effect ◽  
Treatment Application

Abstract. The effects of management after fire in Pinus halepensis forests were assessed in northern Greece. Seeding, logging and building of log barriers were applied in burned sites and compared to a control site. Two years after treatment application, 70–80% of the ground in all sites was covered with vegetation. Seeding with herbaceous plants did not increase plant cover. Logging and building of log barriers negatively affected herbaceous species but increased woody species. During the first spring after fire, the highest numbers of P. halepensis seedlings were observed in the control site and the lowest number in the logged site. Logging and log barrier building had a negative effect on pine regeneration compared to control and seeding treatments. Woody plant composition was similar in control and seeding sites, with dominance of P. halepensis and Cistus species. A different pattern was observed in the logging and log-barrier sites with a low number of seeders and a high number of resprouter species.

scholarly journals RESTORATION OF FORMER GRASSLAND IN SOUTH-CENTRAL TEXAS

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Wendy J. Leonard ◽  
O. W. Van Auken
Keyword(s):  
San Antonio ◽  
Plant Cover ◽  
Woody Species ◽  
Bare Soil ◽  
Grass Species ◽  
Herbaceous Plant ◽  
Percent Cover ◽  
Juniperus Ashei ◽  
South Central ◽  
Central Texas

Abstract In the past, grasslands and savannas were common in many areas of south-central Texas, including the San Antonio area. With the advent of European settlers and their livestock, much of this area was converted to agriculture and rangeland. Today, most of San Antonio is developed, but some preservation has occurred. Restored grassland, mechanically cleared of Juniperus ashei (juniper, Ashe juniper) and other woody species in 2013, was examined and compared to adjacent non-cleared woodland. The woodland examined was dominated by Diospyros texana (Texas persimmon) and Juniperus ashei. Richness in the woodland canopy was 15 species. The understory below the canopy had 25 woody species. In the restored grassland area, herbaceous plant cover was 41.8%, woody plant cover 5.8%, bare soil 2.9%, and litter cover 49.5%. Species richness was 71, with 60 herbaceous and 11 woody species (percent cover of each from <0.1–7.1%). The most common species in the restored grassland in descending order were Nassella leucotricha (Texas winter grass), Calyptocarpus vialis (straggler daisy), Carex planostachys (cedar sedge), Sporobolus crypandrus (sand dropseed), D. texana, and Verbesina virginica (frost weed). Several C4 grass species were present with low cover but may increase in abundance over time. Four of the six most common restored grassland species were present below the woodland canopy and 12 woody species were present in the restored grassland as juveniles. Cost of restoration was approximately $38,500 ($7,500 supplies, $31,000 labor).

Influence of prescribed burning on fruit production in Proteaceae

2010 ◽  
Vol 16 (1) ◽  
pp. 46 ◽  
Author(s):  
T. D. Penman ◽  
S. H. Penman
Keyword(s):  
Community Structure ◽  
Reproductive Output ◽  
Prescribed Burning ◽  
Fire Regimes ◽  
Fruit Production ◽  
Management Tool ◽  
Fire Intensity ◽  
Term Study ◽  
Long Term Study

Prescribed burning is applied worldwide as a forest management tool. It is broadly accepted that altered fire regimes can directly impact upon community structure and composition, but little is known about the indirect effects of altered fire regimes on the mechanisms that produce community-level changes such as changes to the reproductive output of individual plants, hence populations. We examined the reproductive output of four species of Proteaceae within a long term study site where disturbance histories for the last twenty years have been accurately recorded on 216 plots. Frequent fire was found to increase woody fruit production in Banksia marginata, but had no apparent effect on B. serrata, Hakea eriantha or H. sericea. Results of this study vary from a similar study which examined the effect of wildfires. The differences observed are likely to reflect the differing impacts of fire intensity on these species. Indirect changes in fruit production may result in changes in reproductive success of species which in turn may affect vegetation community structure and faunal habitat.

scholarly journals Drivers of woody plant encroachment over Africa

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Z. S. Venter ◽  
M. D. Cramer ◽  
H.-J. Hawkins
Keyword(s):  
Woody Plant ◽  
Woody Plant Encroachment
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