This report covers the time period from 1^st October 2009 until 31^st December 2009. During this time, we have invested over 1 120 man hours in vegetation and animal population dynamics surveys. These are discussed herein.

The amount of work completed is directly proportionate to the availability of resources. Funds and manpower are solicited from international volunteers for this purpose.

The data captured in these reports is designed to advise management as well as demonstrate the effectiveness of management action.

The information contained in this report has been obtained through both casual observation as well as basic monitoring techniques. Although the monitoring techniques are not discussed in this report, they are available on request.

In most cases, sample sizes are acceptable and the majority of OWGR is represented in the samples.

Contributors to this report:

Robbie Prehn – OWGR Committee & Pondoro Lodge

John Slabbert – Transfrontier Africa: Research Assistant

Sean Hill – Student: Game Ranch Management

Craig Spencer – OWGR

Volunteer assistance from:

1. Conservation Volunteers Australia
2. AVIVA Conservation Projects
3. Transfrontier Africa

Veld condition:

1. Grass:    A basic survey to evaluate the grass biomass at the end of the 2009 winter was conducted in October 2009. The purpose of this survey was to:

2.  Gather base-line data with which to compare the end of winter grazing with consecutive years and show trends in response to grazing pressure and rainfall.

3. To evaluate the accumulation of moribund and therefore the potential fire-hazard.

This entailed selecting 31 separate monitoring sites (figure 1) that would represent the reserve in two basic ways: 

1. Water availability: Those areas that have well spaced water provided on a permanent basis, areas that have wind pumped water only and the Cambridge 5 & 6 area that has a multitude of permanent water.
2. Rainfall and soils: Covering enough of the reserve to alleviate the potential bias of erratic rain-fall and edaphically variable areas (different soils).

Figure 1. Spacial representation of the grass survey plots in relation to water-points.

Results and interpretation:

§  In areas where water holes are restricted to those pumped by wind, such as Impalabos East and West, there was a markedly higher grass biomass at the end of winter. Collectively these areas contributed 52.8% of the above-ground grass biomass within OWGR.

§  Cambridge 5 & 6 and surrounding areas contribute approximately 6.68% of the end of winter above-ground grass biomass within the OWGR. Although the soils are of a high quality, this low yield is attributed to the plethora of water-points which allows grazers to concentrate in the area throughout the year.

§  Interestingly the areas such as Pondoro and surrounds that have permanent water, but well spaced, contributes 33.21%  of the above-ground grass biomass at the end of winter.

§  The majority of above-ground biomass of grass was attributed to the species Bothriochloae radicans and Aristida congesta at this time of the year. These are both increaser 2 species and have a very low forage value.

§  Bothriochloae radicans is a sub-climax grass that forms tufts and is often found in clay soils and at the base of termite mounds. Aristida congest, however, is a pioneer grass and does not form tufts. It is one of our more common grasses in OWGR.

§  Almost all grass biomass remaining at the end of winter was found in refugia under fallen trees and at the base of termite mounds (especially true for B. radicans).

§  The lack of grass biomass within 2 kilometers or the river is to be expected. It is perhaps a bit distressing that the winter grazing yield at the end of the 2009 season was comparable with that along the Olifants River (historically the only permanent water).

§  Areas that pump artificial water by means of wind-pumps displayed a high grass biomass which is attributed to a lower grazing pressure during wind-free (and therefore water free) winter months.

§  It can also be said that areas such as Pondoro which has well distributed water holes also enjoys a higher grass biomass.

§  Soil conditions play a major role in the capacity of an area to support grass biomass.

Figure 2. Chart representing the percentage biomass in relation to the water point categories.

It must be born in mind that historical land-use practice will also contribute to results. IE. If the area was subjected to intensive grazing or a fire regime, etc.

Figure 3. A representation of the percentage biomass in relation to the areas within the OWGR study area.

Results and interpretation:

§  In areas where water holes are restricted to those pumped by wind, such as Impalabos East and West, there was a markedly higher grass biomass at the end of winter. Collectively these areas contributed 52.8% of the above-ground grass biomass within OWGR.

§  Cambridge 5 & 6 and surrounding areas contribute approximately 6.68% of the end of winter above-ground grass biomass within the OWGR. Although the soils are of a high quality, this low yield is attributed to the plethora of water-points which allows grazers to concentrate in the area throughout the year.

§  Interestingly the areas such as Pondoro and surrounds that have permanent water, but well spaced, contributes 33.21%  of the above-ground grass biomass at the end of winter.

§  The majority of above-ground biomass of grass was attributed to the species Bothriochloae radicans and Aristida congesta at this time of the year. These are both increaser 2 species and have a very low forage value.

§  Bothriochloae radicans is a sub-climax grass that forms tufts and is often found in clay soils and at the base of termite mounds. Aristida congest, however, is a pioneer grass and does not form tufts. It is one of our more common grasses in OWGR.

§  Almost all grass biomass remaining at the end of winter was found in refugia under fallen trees and at the base of termite mounds (especially true for B. radicans).

§  The lack of grass biomass within 2 kilometers or the river is to be expected. It is perhaps a bit distressing that the winter grazing yield at the end of the 2009 season was comparable with that along the Olifants River (historically the only permanent water).

§  Areas that pump artificial water by means of wind-pumps displayed a high grass biomass which is attributed to a lower grazing pressure during wind-free (and therefore water free) winter months.

§  It can also be said that areas such as Pondoro which has well distributed water holes also enjoys a higher grass biomass.

§  Soil conditions play a major role in the capacity of an area to support grass biomass.

Figure 2. Chart representing the percentage biomass in relation to the water point categories.

It must be born in mind that historical land-use practice will also contribute to results. IE. If the area was subjected to intensive grazing or a fire regime, etc.

Figure 3. A representation of the percentage biomass in relation to the areas within the OWGR study area.

Figure 4. Graph showing the distribution of grass biomass within the study area.

It should also be born in mind that the area received an above average rainfall for the season and therefore these figures could represent a best case scenario.

Table 1. Biomass per hectare in relation to area and water sources.

• As mentioned in the previous report, many of our grasses appear to be shade-loving and achieved a visibly higher biomass under bushes and shrubs or fallen trees. Cleared areas and exposed areas show the lowest above-ground grass biomass. This is attributed to both the reduced grazing pressure as animals struggle to access grasses growing in refuge under fallen trees, etc., as well as the micro habitat that is created (shade and lower evaporation rates / better water retention). It is therefore recommended that further bush clearing by land-owners be discouraged until further trials can be conducted to determine a best practice model.

In conclusion, it must be reiterated that in a semi-arid savanna such as ours, a healthy fire would require as much 2 500 kg per hectare of moribund.  was observed and there is insufficient fuel to support a “healthy” burn. It can therefore be established that we are well below the threshold for successful burns as an ecological management tool in the OWGR. This will be monitored over the years.

For the purposes of managing fires within our region, a flow-chart has been designed to assist with this in the field. This is attached as Appendix 1.

1. Woody species:  The Visibility Index at the end of winter 2009 was calculated in September and October and had increased dramatically as expected.

In the absence of foliage on the woody species, visibility improved from 19.48 metres from the road verges, up to 31.55 metres.

Table 2. Comparing Visibility Index between the best and worst case scenario. Measured in metres.

This was measured at the peak of the growth period (March) and again in this reporting period just before the rains.

• Methodologies were briefly discussed in the previous report.

A snap-shot of the influence of elephants on our woody species has been compiled and is attached as Appendix 2.

Water Points

A map showing the significant water points and their recharge methods is almost complete. The Oxford and Cambridge 5 & 6 areas are still under-represented and will be visited during the following reporting period.

Water quantity and quality surveys are still conducted on a monthly basis and showed that all dams and pans were full. Several, including the Singwe Big Dam were over-flowing following our good November rains and water quality was good for all water-points.

Figure 5. Spacial representation and recharge methods for water-holes captured to date.

Subterranean water

The area that has the potential to impact the sub-terrainian water the most is the Cambridge 5 & 6 section of the Reserve. I base this on the multitude of bore-holes within close proximity of each other.

Of the sites that we continually monitor, the Singwe Bush-camp main site (under the windmill) and the control site is no longer accessible as a result of recent up-grading of these sites.

Despite the good early rains, it would appear that the subterranean water is under pressure and this will only increase as development of the Cambridge 5 & 6 holdings continues.

The results are as follows:

Figure 6. Bore holes measured on the reserve compared with a 12 month average. Singwe Main has been removed as the bore-hole has been capped.

All sites show a below average value and this should be cause for caution. This is true for sites that are not abstracted and this would indicate that there is a correlation with the recharge rates and rain-fall to date and therefore it cannot be assumed that the below average values are related to over-abstraction. The Billy’s Lodge bore-hole that has dropped approximately three metres, displayed the same pattern in February 2009. By March it had recovered and perhaps this is related to the occupancy of the properties during the summer season? Although my data is little more than a snap-shot of two years, it would appear that this trend is typical for this time of year.

Predator / Prey relationships

The ongoing data-capture exercise that has been initiated in conjunction with Pondoro Lodge to capture data relating to as any kills within the reserve, continues.

§  Hyena activity has been observed in the areas adjacent to Ukhozi and on Impalabos. Furthermore, calls and sightings continue to increase in the area and Ezulwini Paradise Camp has been visited on several occasions by a group of three spotted hyena who appear comfortable with human activity.

§  Leopard sightings continue to improved and the frequency of sightings have escalated as the leopards become habituated to human activity. Sightings are still frequent on Pondoro and surrounds as well as Cambridge 6 and Singwe South.

§  Several black-backed jackals that were suffering from Sarcoptic mange have recovered. However, it would appear that several pups were lost in late December to this parasite. Our Jackal populations appears stable.

§  Sightings of civets and other smaller predators are frequent. Caracal remain elusive with infrequent sightings and serval continue to be absent.

§  Sightings of the same adult female cheetah and two sub-adults have been recorded frequently again during this period and we were graced with the arrival of a collared female cheetah which has been seen frequently

§  Lion pride dynamics are as per the previous report and all lions have been accounted for during this reporting period.

Table 3. Predator acceptance frequencies in OWGR over the reporting period.

Lion continue to favor buffalo as their chosen prey species and although wildebeest make up a humble 9.33% of their kill rate, this amounted to 88% of the wildebeest population according to the aerial census. This is a shocking figure if the census results are a true reflection of the animal numbers. However, our wildebeest herds that we have under management number a total of 31 animals and this is just a small snap-shot. Irrespective, the acceptance frequency may be low for wildebeest, but the following table will in demonstrate the importance of seeing this in context with the population size.

Table 4. Percentage of each species population that was taken by predators in this reporting period. Based on 2009 aerial census.

Opuntia ficus-indica (Prickly Pears) are still being tackled systematically in the area and are logged using a GPS. A database of their location is kept and plants treated with MSMA are re-visited to ensure that they have been effectively treated. Land owners on Ezulwini, Impalabos East and West have been pro-active in the eradication of these weeds. The areas of Rome 1 to 4 have not been surveyed as yet.

Figure 7. Prickly Pears treated or identified for treatment during this reporting period.

FOCAL SPECIES – INDICATORS AND KEY-STONE SPECIES

1. AFRICAN ELEPHANTS:

1. Elephant movements, impacts on vegetation and population dynamics:

Mega-herbivores are our major landscape architects in the region and are critical to the ecological processes of the savannah biome. Elephants have a controversial impact on the vegetation within the savannah biome and this is monitored along with their movement patterns and herd dynamics. This is a major focus of this project and we have partnered with the Save the Elephant Foundation and the Trans-boundary Elephant Research organisation for this purpose.

§  During this reporting period, 17 elephant sightings were recorded between October and December, with a noticeable absence of elephants for the past 24 days. The profile of elephants frequenting the area remains as young bulls with the odd breeding herd making an appearance. All sightings and documented according to the prescribed data-capture regime of the Save the Elephant Foundation. This includes several breeding herds and bulls. This data is handed on a regular basis to Drs. Henley. Much data was lost due to the lightening strike that destroyed our computer equipment.

Table 6. An example of the field – data – capture forms utilised for the elephant sightings.

1.2 Elephant influence on woody species:

The influence that elephants have on the woody species within the reserve is an important issue to understand. As a result, we have designed a monitoring protocol to assess this on a fine scale.

§  This monitoring regime comprises three transects that represent the vegetation communities of the reserve as well as the influence that roads have in the movements of elephants.

§  Plots are established in these transects and woody species are examined for damage caused by elephants.

§  Elephant related damage is quantified and the tree/shrub’s response is also noted.

§  An acceptance frequency of target species (Gadd, M. 1997) is employed to determine the preferred target species of trees or shrubs.

Table 7. Example of field data capture sheet employed to assess the fine-scale impacts of elephants on the woody vegetation.

 

TREES VS ELPHANTS

Date

18-Nov-08

Transect start

Height of tree

Plant data

Spp.

1.5m-2.5m

2.5m-4.5m

>4.5

Multi stem

Single stem

Damage

minor

average

major

Bark strip

Limb broken

Up-rooted

Dead

Coppicing

Healed

Pathogens / Rot

Browsing signs

GPS - S24.09.360 E 30.56.917

Raintree

x

x

x

Raintree

x

x

x

x

x

x

Weeping Wattle

x

x

x

x

x

x

Raintree

x

x

x

x

Knobthorne

x

x

x

x

x

x

x

Knobthorne

x

x

x

x

x

GPS - S24.09.407 E030.56.924

Bushwillow

x

x

x

x

x

x

Knobthorne

x

Raintree

x

Shepphard's tree

x

x

Russet Willow

x

x

Magic Guarri

x

x

Corkwood

x

x

x

Corkwood

x

x

Table 8: The varying forms of damage to three different height classes of trees with percentage of damage caused.