A study on the structure and composition of Androstachysjohnsonii Prain (Euphorbiaceae) woodlandacross three strata was conducted in GonarezhouNationalPark (GNP), southeastZimbabwe. Specifically, the objectives of the study were: (i) to determine the spatial structure and composition of A. johnsoniiwoodland in GNP and (ii) to determine factors that influence the structure and composition of A. johnsoniiwoodland in GNP. This study was based on a stratified random design with three major soil groups, and 30 plots were sampled in May 2010. The three soil strata were comprised of soils derived from (i) rhyolite, (ii) malvernia and (iii) granophyre bedrocks. A total of 1258 woody plants were assessed and 41 woody species were recorded. There were significant differences in mean tree heights, tree densities, basal area and species diversity in A. johnsoniiwoodlandacross the three soil strata. In contrast, there were no significant differences in the mean number of dead plants per ha in the three study strata in the GNP. Our study findings suggest that A. johnsoniiwoodland in GNP is being degraded. GNP management should develop a monitoring program through establishing monitoring plots in A. johnsoniiwoodland, and further studies need to be carried out, particularly on recruitment of A. johnsonii in the GNP.
We investigated the structure and composition of Spirostachys africana woodlands in GonarezhouNationalPark (GNP), southeastZimbabwe. We divided the GNP into three strata, namely northern, central and southern GNP, based on physical feature such as major perennial rivers. The main objective was to determine whether the structure and composition of S. africana woodlands varied across the GNP. In addition, we evaluated whether herbivory and fires played important roles in influencing the structure and composition of S. africana woodland stands. A stratified random sampling design was used and data were collected from a total of 60 sample plots. The following variables were recorded in each study plot: woody plant height, species name, plant status (alive or dead), fire or browse evidence and number of stems per plant. A total of 2,588 woody plants comprising of 73 woody species were recorded from the sampled S. africana woodlands in the GNP. Our results showed that woody species diversity, woody plant heights, shrub density, density of dead plants, sapling density, density of fire damaged plants, and number of stems per plant were significantly different across the S. africana woodlands in GNP. In contrast, only densities of trees and browsed plants did not differ significantly across the GNP. Most plots in the southern GNP had higher tree and sapling densities and taller trees whereas those in the northern GNP had higher densities of fire damaged plants. In addition, plots from central GNP were characterised with higher shrub densities of S. africana woodlands. Overall, our results suggest that there are both structural and compositional differences of S. africana woodland stands across the GNP. Evidence of herbivory did not differ significantly across the GNP suggesting that plants were uniformly affected by herbivores. However, fire evidence seemed to vary across the GNP, with areas having frequent fires being more degraded and having to some extent more woody vegetation species diversity.
In protected areas such as GonarezhouNationalPark (GNP), southeastZimbabwe, large herbivores and fires have a significant negative impact on vegetation structure and composition thereby threatening local extirpation of some plant species (O’Connor et al., 2007). Marula is one of the heavily utilized tree species facing pressure from elephants and humans in savanna ecosystems (Helm & Witkowski, 2013). Gadd (2002) asserts that the marula species has poor regeneration and recruitment ability which is mainly attributed to overutilization. With the increasing human and large herbivore populations in southeast lowveld of Zimbabwe, the survival of the marula species is a cause of concern mostly due to overutilization. Elsewhere, in South Africa, the marula species is regarded as a keystone species, hence, this contributes towards its conservation (Shackleton et al., 2007). To date, little is known about the population density and structure of the marula species in the south eastern lowveld of Zimbabwe. Therefore, the present study provides a baseline assessment of the marula species in GNP and adjacent areas. The objective of this study was to assess the population density and structure of marula (Sclerocarya birrea) in the northwestern GNP and adjacent areas.
The results of the present study show that there were significant differences in basal area, browsed plant density, shrub density and species diversity across the three strata in GonarezhouNationalPark. The structural and compositional differences across the three strata in GonarezhouNationalPark were possibly related to herbivory, fires, human activities, droughts, geology and soil differences (Tafangenyasha, 1997a, 1998; Gandiwa and Kativu, 2009; Gandiwa et al., 2011a, b). Repeated fires and elephant browsing are known to stress normal growth and affect the health of the woodland and may top-kill woody vegetation (Bond, 2008; Ryan and Williams, 2011; Asner and Levick, 2012). Furthermore, elephant populations in GonarezhouNationalPark have over the years continued to increase, from ~3100 in 1969 to ~9100 in 2009 (Dunham et al., 2010). This increase may also have been influenced by the recent non-culling of elephants in the park since the last elephant cull in GonarezhouNationalPark was conducted in 1993. Tsetse fly (Glossina spp.) (Diptera: Glossinidae) eradication teams cleared riparian woodlands from parts of the major river systems, i.e. Save, Runde and Mwenezi, in GonarezhouNationalPark, also negatively influencing the woody vegetation (Gandiwa and Kativu, 2009).
Results showed differences and similarities in woody vegetation structure and composition between Manjinji Pan and Save-Runde Junction IBAs. Tree density and number of stems per plant differed whereas plant height, density of shrubs and dead plants were similar in both study areas (Table 2). Tree densities and number of stems per plant could have differed due to interaction of fires and herbivory effects leading to a lower tree density and an associated high number of stems per plant primarily from resprouting in Save-Runde Junction IBA than in Manjinji Pan IBA. Intensive browsing by mostly large herbivores such as elephants and repeated fires are known to open up woodlands through breaking and killing of mature trees (Skarpe et al., 2004; O’Connor et al., 2007; Guldemond and Van Aarde, 2008). Previous studies on vegetation structure and compositionacrossvariouswoodland types in GonarezhouNationalPark have also attributed the lowering of tree density and high numbers of stem per plant to herbivory and fires (Tafangenyasha, 1997; Gandiwa et al., 2011; Mpofu et al., 2012). Higher tree density and lower numbers of stems per plant in Manjinji Pan IBA could be attributed to lower negative impact of browsing by goats and low fire occurrences in adjacent communal land due to low fuel load resulting from heavy grazing by livestock.
Our Homeschool Enrichment Academy is an opportunity for students who are homeschooled to participate in a variety of enrichment classes in a structure school setting one day a week. This program does not provide core curriculum, but would complement your own homeschooling curriculum or WPSD Online programs. Students in Grades K-5 could attend one day a week at either Gateway Elementary or Summit Elementary with Sandy Struble or in Grades 6-8 at Summit with Diana Roberts. During that time, students participate in PE, Art, and Music, hands-on Science labs, Public Speaking, Robotics and Technology as well as learning opportunities in our Media Center. Middle School students could also receive some additional support or tutoring in writing or math. Other options could include literacy assessments and school-wide events, programs and assemblies.
In species with high mortality rate depending on density, adult individuals tend to present less aggregate distribution than seedlings (CRWLEY, 2005). This characteristic was observed in this study, where mature individuals mainly presented uniform distribution pattern, both in the core and the edge sites.
Anjos et al. (2004) obtained different results, where more preserved and less exploited areas showed random and aggregate distribution. In preserved areas, but with uncontrolled seed harvesting by humans, distribution pattern was regular and aggregate. Souza et al. (2008) also met different results, where, in preserved sites, distribution pattern of females was random. Those differences reflect different population structure and conservation status of the analyzed sites, being aggregate and uniform pattern the normally observed araucaria distribution standard.
The map introduced in this article depicts the state of the vegetation in HNP and surrounding reserves and land concessions in 2013–2014 (Figure 5), 20 years more recently than the previous map of the entire park (Rogers 1993). The vegetation classes distinguished in it are rather broad classes defined on the basis of vegetation structure. In particular, the classes reflect variability in openness and vegetation height, which we consider to have important and numerous functional consequences. For instance, in our own work on large mammal ecology, we have previously shown that dense and bushy areas where visibility is low, rather than dense woodlands where visibility is greater, are selected for by lions, which are ambush predators (Davidson et al. 2012). Thus, we think that the classes identified should be useful to map and understand functional processes at the landscape scale. Also, the map produced here offers baseline data to monitor, at a large scale, changes in these key variables (openness and height). In HNP, this is particularly important in the face of the persistence of a large elephant population that may affect vegetation structure in the long run (Valeix et al. 2011). As this map was validated via a simple random sampling scheme, its classes can be combined to create other maps with
2018 ). These studies found that, when grazing pressure increased, cattle were forced to graze forage in the lower strata which was of lower quality and as a result diet quality and animal performance declined. It is important to quantify the herbage quality of different strata of kikuyu pastures to assist members of the grazing industry in making informed decisions on grazing management, based on a sound understanding of the effects of sward structure on diet quality. The aim of this study was to quantify the effects of stage of regrowth and vertical distribution in the sward on physical composition and nutritive value of kikuyu pastures.
Meru Betiri NationalPark (MBNP) is one of the nature conservation area that has the potential of flora, fauna, and ecosystems that could develop as a nature-based tourism attraction. The existence of certain indicator species was related to estimation of stress level and disturbance on ecosystem stability for making strategic decisions about the restoration in this area. One of the important indicator species at forest ecosystem were soil arthropods. Aim this research were analyzed composition and diversity of soil arthropods at Rajegwesi, MBNP areas. The methods in this research used pitfall trap, measurement of distribution structure and soil arthropods composition based on the Shannon - Wiener index, Morisita similarity index and Importance Value Index (IVI). The number of families and individuals of soil arthropods found in the coastal area of Rajegwesi consists of 10 order with 21 families (702 individual). The number of individuals of the order Hymenoptera, Coleoptera, Collembola and Araneida was more widely found. Soil arthropods diversity index on each land use indicated that soil arthropod diversity in these areas were moderate. Soil arthropod community of orchards and forest had a similarity of species composition, whereas soil arthropod community of savanna had a similarity of species composition with paddy fields.
With the availability of aerial photographs at 1:25 000 scales or less over a range of years and rea- sonably good records of the fire history since the NationalPark was formed, there is considerable potential to test for an association between fire, vegetation structural change and tuart canopy health. Fensham et al. (2002) have demonstrated a robust method enabling the quantification of vegetation cover change with image scales up to 1:40 000. The availability of other data such as soil type, offers the further possibility to explore interactions between vegetation change, fire and other environmental factors. Data collection in this way would represent a superior approach to the standard “space for time” method in isolation. In conjunction with this, on-ground experimental work is being established to examine the response of tuart, co-occurring tree species and the under- storey to fire intensity as well as competition and post-fire grazing effects on seedling regeneration. A broader project investigating tuart tree decline in Yalgorup and elsewhere has commenced. It acknowledges that the causes of tree decline are rarely simple or single-factored. Preliminary work suggests there is no single cause of the decline/declines across the distribution of tuart (Longman & Keighery 2002, Edwards pers. comm.). Primary and secondary agents, complex interactions and time lags between cause and effect are all possible. Collaboration between research groups and the co-ordination of research across several areas: fire, insects, fungal pathogens, nutrition, hydrology and water relations, represents the best hope for gaining the knowledge necessary to undertake any remedial work or prevent any further decline.
In conclusion, BADL plays a vital role in protecting and managing some of the largest remnants of native mixed-grass prairie in the region. Many areas of the park have a high cover of exotic species, and to retain ecological integrity it is important to continue efforts to reduce the cover of invasive plants. Yellow sweetclover and annual bromes present a large challenge to managing grasslands in BADL, and more research on effective management strategies in the mixed-grass prairie is greatly needed. Allowing natural disturbances such as fire, grazing, and prairie dog use may be critical to maintaining plant diversity in BADL, but it should be balanced with the need to protect intact native communities and prevent further invasions of exotic species. Continued monitoring efforts will be critical to track changes in the condition of the vegetation communities in BADL.
Although the contribution of termite mounds to ecosystem heterogeneity is well studied, the influence the environment and other termite colonies have on mound spatial patterning and structure is still poorly understood, despite the profound implications these dynamics can have on ecosystems. Here, we mapped the distribution and size of both active and inactive Macrotermes mounds in eight 1 km 2 plots on granite and basalt geologies in a Zimbabwean savanna. Although mound density was not significantly different between basalt (5.5 ha -1 ) and granite (6.1 ha -1 ), the underlying geology influenced termite mound structural attributes and spatial distribution pattern. Mound size distributions differed between the geologies and mounds were 2.6 times taller, 3.9 times wider and had 15 times greater lateral surface area on granite. Subsequently, 6% of the total landscape area was covered by mounds on granite compared to only 0.4% on basalt. On granite, large mounds exhibited significant over- dispersion at scales below 30 m, and small mounds were clustered around large ones. In contrast, random patterning was present on basalt. Over-dispersion of large mounds on granite signifies density dependent thinning. Small mounds clustering around big mounds on granite was not viewed as facilitation, but rather “budding” of new colonies comprising fully fledged castes less vulnerable to competition. The distribution of inactive mounds also differed between the two substrates, with inactive mounds significantly clustered on granite, but not on basalt, suggesting that colony death on granite may be a consequence of localised events such as water inundation and/or disease rather than larger scale natural processes. Our results demonstrate a powerful influence of geological substrate on mound spatial patterning and structure, suggesting that the importance of termite mounds for ecosystem functioning is more pronounced on nutrient poor granitic substrates than basalts because of the pronounced over-dispersion and much larger mound size here. However, species composition between granite and basalt differs and that different species have different mound characteristics. So, geology may not directly affect mound spatial patterning via chemistry or physics but indirectly via differences in species composition.
This is one o f the Cambridge Tropical Biology Series and maintains the high standards which have become associated with the Cambridge University Press. Peter Endress, although based in Zurich, has a long and productive association with the tropics and maintains that he actually started this book during the monsoon in Java Endress is a developmental morphologist who has published extensively on floral structure and development in primitive groups of flowering plants. His approach to the topic in hand is decidedly that o f an evolutionary morphologist. This provides a refreshing zest to a topic which is not well documented ex perimentally and thus liable to an uncritical and even anecdotal exposi tion. Indeed he starts off by citing the instance of that most familiar of tropical ornamental trees, the Flamboyant, Delonix regia. For all its ob vious attractions little is known about its reproductive biology in the wild (although I think the fact that it is rare in its natural home in Madagascar might well have something to do with this). But the point is well made nevertheless. The biology of flowers can provide insights into trophic and evolutionary relationships within the community. This facilitates an understanding of community dynamics which could not be gleaned from even the most comprehensive checklist. Anyway, a botanical inventory o f the tropics is still far from complete, yet even as new species are being described, others are disappearing and all that is known to Science about them are their names. After all, the most informative aspect of a species is not what it looks like but how it functions. Endress is aware o f this, and while nothing in his book is startlingly new, it is a compelling synthesis which provides a firm grounding, both philosophically and in tellectually, from which to proceed.
Field and laboratory work: Field data were obtained from several samples between August 1997 and September 1999 with three more intensive samples (two-week long) in August 1997, July 1998 and August 1999. The sampling method consisted of transects during not less than one hour (see Price et al. 1998). Along the selected collecting sites all plants were searched for galls. Seventeen sites rep- resenting the main terrestrial habitats in Coiba NationalPark were surveyed (Table 1, Fig. 1). Plants with galls were collected and photo- graphed. Specimens of galled plants were dried and put into a herbarium collection, where plants were identified later. Samples of the galls were also stored in 70% ethanol to allow further dissection and identification. Data of altitude and geographic position was taken in the field (Table 1).
Another option is to raise significantly the charges for the government-owned lodging within the parks themselves. Although these lodge facilities are not luxurious, they are often spacious, clean and otherwise attractive – especially considering the locational advantages that they offer to visitors who will spend most of their time touring the park itself. It seems likely that many foreign visitors would be happy paying fees of US $50 to US $100 per night per person for existing lodging units in some parks. Given a significant increase in revenues, it would also be possible to improve housekeeping, maintenance and the general service quality of government lodging facilities, thus raising the willingness to pay for them of foreign visitors. However, at present typical park fees for lodges are more in the range of US $5 to US $10 per night. Such lodging fees in many parks are clearly well below the going market rate. One might say that much lower income Zimbabwe taxpayers are subsidizing much richer foreign tourists who are making use of nationalpark lodging facilities.
An alternative view of the democratic function of national parks can be seen in the catchment protection and cultural heritage arguments. Here, the existence of a wider public interest is implied. Individuals must be prepared to give up some benefits (in this case unlimited use of national parks) for the greater benefit of the whole community. This voluntary regulation for the good of society is the other side of democracy - it is assumed that freedom can only be achieved through order. Although such regulation was accepted in everyday life, in the 1940s it was not clearly perceived in regard to national parks and the 'freedom of use' aspects were stressed much more in regard to national parks than the restrictive aspects. This was emphasised by the great value given to personal experience of national parks by all nationalpark supporters.
The deconstruction of cellulose, hemicellulose, and lignin has varying effects on lignocellulosic biomass. To understand and evaluate these effects it is important to conduct compositional and structural analyses. In this study, the effect of different pretreatments on the composition and structure of water hyacinth (WH) was investigated. The pretreatment methods investigated were acid, alkali, ionic liquid (IL), and microwave- alkali. The structural analysis was completed before and after the pretreatment using scanning electron microscopy. In addition, the biomass recovery rate was measured to evaluate the composition of the WH biomass. Based on the results, all pretreatment methods effectively disrupted the crystalline structure and enhanced the digestibility of the WH through increasing the cellulose and hemicellulose content and reducing the lignin content. The acid pretreatment resulted in high cellulose digestibility while the microwave-alkali pretreatment destroyed only the lignin structure of the WH. The alkali and IL pretreatments increased the cellulose and hemicellulose content of the WH. The highest recovery rate was obtained via IL pretreatment. The acid, microwave-alkali, and alkali pretreatments had the second, third, and fourth highest recovery rates, respectively. This study showed that the biomass recovery rate, compositional makeup, and structural analysis are important to use WH for bioenergy production.
Questioned as to who should take responsibil- ity for climate change issues in the area the view- point of accommodation managers was that it was shared and that a number of stakeholders should bear responsibility. These include the national gov- ernment, the international community, the tourism sector, local authorities, Hwange tourism compa- nies as well as NGOs. Of this array of stakeholders it was considered by interviewees that the national government of Zimbabwe was most responsible for investing more resources to combat the impacts of climate change. The responses by the tourism indus- try of being reliant on and waiting for government interventions and leadership on responding to cli- mate change aligns with findings in other parts of the world (see Prideaux et al., 2013). Arguably, how- ever, the implementation of structural changes and policies by national government that might mitigate the effects of climate change and assist in propelling more sustainable ways of operating tourism enter- prises was not what the respondents were referring to. Rather it was a call for the imperative need for a quicker government response to repair the short and long-term damages caused by extreme weath- er. Little or no consideration was given to long term solutions such as amending sustainable tourism business models or national environmental policies. Indeed, the most typical response from accommo- dation managers was that “the government should perform infrastructural maintenance and repairs in a timely manner, as infrastructure such as roads and bridges are in dire need of attention”. Sub-standard infrastructure, bush fires, water shortages and unre- liable electricity supply were viewed by most man- agers as the major issues that they face. Whereas as indicated above energy and water saving measures have been introduced at lodges such as photovolta- ic solar power, water heaters, the use of LP gas and boreholes these were prompted by the imperative for business survival.
This research was carried out in the Seribu Islands NationalPark located in the geographical position of 5° 24'- 5° 45'S and 106° 25'- 106°40'E (Figure 1). The study was conducted in September during the transition monsoon. Monitoring, data collection and identification were done directly on site. Four islands were selected as representatives for zonations in the Seribu Islands NationalPark.