Final Report BASELINE STUDY on THE

BASELINE STUDY ON THE DISTRIBUTION AND ABUNDANCE OF ALIEN INVASIVE SPECIES (PROSOPIS) IN THE ORANGE AND FISH RIVERS IN NAMIBIA

Final Report

Date: 11 December 2020 Report No: ……ORASECOM UNDP/GEF

The Support to (The Baseline Study on Distribution and Abundance of Alien Invasive Species (Prosopis) in the Orange and Fish Rivers in Namibia) was commissioned by the Secretariat of the Orange-Senqu River Commission (ORASECOM) with financial and technical support from the Global Environment Fund (GEF) through the United Nations Development Programme (UNDP).

Prepared by

Tortoise Environmental Consultants(TEC)

ORASECOM SECRETARIAT

(THE BASELINE STUDY ON DISTRIBUTION AND ABUNDANCE OF ALIEN INVASIVE SPEICIES (PROSOPIS) IN THE ORANGE AND FISH RIVERS IN NAMIBIA)

Approved by the Consultant:

……………………………………. ……………………………………. Jonas Heita Date Environmental Consultant – Director

ORASECOM SECRETARIAT Approved for ORASECOM by:

……………………………………. ……………………………………. Mr Lenka Thamae Date

TABLE OF CONTENTS

BACKGROUND AND INTRODUCTION...... 1 Introduction ...... 1 Terms of Reference (ToR) ...... 1 Objectives ...... 2 Scope of the study as outlined in the ToR ...... 2 Deliverables ...... 2 STUDY AREA ...... 4 The Orange – Fish River Basin...... 4 METHODOLOGY ...... 6 Methodology ...... 6 Mapping of the distribution and density of Prosopis ...... 6 Identification of sample sites and plots ...... 6 Assessments of Prosopis abundance and density ...... 11 Assessment of the impacts of Prosopis on biodiversity of plant communities ...... 11 Data Capturing analysis ...... 17 Training on methodologies for evaluating the presence and extent of Prosopis ...... 18 INVENTORY OF PROSOPIS IN THE ORANGE-FISH RIVER BASIN ...... 19 Introduction of Prosopis to Namibia ...... 19 Results on the distribution and density of Prosopis in the Fish-Orange Basin 20 Overall abundance and density of Prosopis in the Fish and Orange Rivers 22 Abundance and density of Prosopis in the Fish River ...... 22 Abundance and density of Prosopis in the Orange River ...... 23 Abundance of Prosopis Seedlings in the Fish and Orange Rivers .... 24 Height and canopy cover of Prosopis in the Fish and Orange Rivers 25 Health conditions of Prosopis in the Fish and Orange Rivers ...... 28 Number of Prosopis in relation to Other Species ...... 29

Data Interpretation ...... 30 Distribution and abundance of Prosopis ...... 30 Prosopis Seedlings ...... 31 Variations ...... 31 Relationship with other Species ...... 32 Prosopis Distribution and Abundance Maps – Overall Maps ...... 33 Entire Orange – Fish Basin ...... 33 Fish River Section ...... 35 Orange River Section...... 36 Prosopis Distribution and Abundance Maps – Fish River Sub-sections ... 37 Fish River – Very high Density ...... 37 Fish River – High Density ...... 39 Fish River – Moderate Density ...... 41 Fish River – Low Density ...... 43 Fish River – Very Low Density ...... 45 Fish River – Bare Land...... 47 Fish – Orange River Confluence (Low – High density) ...... 49 Prosopis Distribution and Abundance – Orange River Sub-sections ...... 51 Orange River – Very high Density ...... 51 Orange River – High Density ...... 53 Orange River – Moderate Density ...... 55 Orange River – Low Density ...... 57 Orange River – Very Low Density ...... 59 GROUND WATER MONITORING PLAN ...... 61 Excessive Water Use ...... 61 Monitoring boreholes ...... 61 Water uptake and Impacts of Prosopis in the Orange – Fish Basin ...... 64 Recommendation for a groundwater monitoring plan ...... 65 Recommendation for a groundwater monitoring plan ...... 65 Establish baselines ...... 66 Establish a groundwater monitoring schedule and analytical Programme ...... 66 Implement groundwater monitoring Programme ...... 66

Develop a groundwater simulation model ...... 66 PROSOPIS CONTROL PROJECTS ...... 68 Review of previous and/or ongoing projects for clearing Prosopis ...... 68 Working for Water Programme – South Africa ...... 68 Gibeon and /Ais - /Ais Case Studies ...... 68 Recommendations for community Prosopis project...... 70 Institutional arrangements and organisation of harvesters ...... 71 Dissemination of information and awareness raising to create a sense of ownership and solicit support ...... 72 Creation of incentives for harvesters ...... 73 Resource Mobilization ...... 74 Marketing of Prosopis firewood ...... 75 Creation of Management Information System/Database ...... 76 Monitoring and Evaluation of socio-economic indicators (consider combining with biophysical ones) ...... 76 CONCLUSION...... 78 REFERENCES ...... 79 ANNEXURES ...... 81 Implementation Model / Conceptual Framework...... 81 Proposed Groundwater Monitoring Plan for the Orange – Fish Basin .... 81

FIGURES

Figure 2-1: The Study Area – Orange Fish River Basin ...... 5 Figure 3-1: Sampling Sites for Prosopis distribution and density in the Orange – Fish River Basin (Author, 2020) ...... 8 Figure 3-2: Sampling Transects, Site #1 Maltahohe – Nomstas, Fish River (Author, 2020)...... 9 Figure 3-3: An illustration of how the transects and plots were demarcated for along the Fish and Orange Rivers...... 10 Figure 3-4: Marking a 10m quadrant (plot) across the Fish River at Nomstas in Maltahohe, ...... 12 Figure 3-5: Marking a 10m quadrant (plot) along the Orange River at ...... 12 Figure 3-6: Marking of Plots using measuring tapes through dense Prosopis infestation ...... 13 Figure 3-7: Navigating through dense Prosopis infestation during the baseline assessment ...... 13 Figure 3-8: Taking measurement of Diameter at Breast Height (DBH) using the Callipers in the plots...... 14 Figure 3-9: Identification and record of flowering Prosopis plants ...... 14 Figure 3-10: Determining height of the Prosopis trees using the human height methodology, where an identified individual’s height is measured and he/she stands at the bottom of the tree while another person moves 30-40 meters away to estimate how many of the individual makes the entire tree to the top...... 15 Figure 3-11: Count and recording of seedlings in the plots, as an indication of regenerative growth within the plots and areas...... 16 Figure 3-12: Prosopis Regrowth after harvesting ...... 17 Figure 4-1: Total density of Prosopis trees per hectare in the Fish and Orange River ...... 22 Figure 4-2: Density of Prosopis seedlings/saplings in the Fish and Orange Rivers ..... 22 Figure 4-3: Total density of Prosopis trees per hectare across the six (6) locality/towns in the Fish River ...... 23 Figure 4-4: Density of Prosopis seedlings/saplings in the Fish River ...... 23

Figure 4-5: Total density of Prosopis trees per hectare across the six (6) sites located in the Orange River ...... 24 Figure 4-6: Density of Prosopis seedlings/saplings in the Orange River ...... 24 Figure 4-7 – Abundance of Prosopis seedlings/saplings in the Fish River ...... 24 Figure 4-8 – Abundance of Prosopis seedlings/saplings in the Orange River ...... 25 Figure 4-9 – Average height of Prosopis in the Fish and Orange River...... 25 Figure 4-10 – Average height of Prosopis in the Fish River...... 25 Figure 4-11 – Average height of Prosopis in the Orange River...... 26 Figure 4-12: Relationship between Prosopis height and canopy area in the Fish and Orange River ...... 27 Figure 4-13: Health condition scoring along the Fish and Orange Rivers ...... 28 Figure 4-14: The graph illustrates the relationship between no. of Prosopis vs other species ...... 30 Figure 4-15: Fish River – Prosopis Distribution – Very high density ...... 38 Figure 4-17: Fish River – Prosopis distribution – High density sections ...... 40 Figure 4-18: Fish River – Prosopis distribution – Moderate density ...... 42 Figure 4-19: Fish River – Prosopis distribution – Low density ...... 44 Figure 4-20: Fish River – Prosopis distribution – Very Low density ...... 46 Figure 4-21: Fish River Prosopis distribution – Bare Land...... 48 Figure 4-22: Orange River – Prosopis distribution – Very high density ...... 52 Figure 4-23: Orange River – Prosopis distribution – High density ...... 54 Figure 4-24: Orange River – Prosopis distribution – Moderate density ...... 56 Figure 4-25: Orange River – Prosopis distribution – Low density ...... 58 Figure 4-26: Orange River – Prosopis distribution – Very Low density ...... 60 Figure 5-1: Existing Ground Water Monitoring Boreholes in the Orange – Fish River Basin ...... 62 Figure 5-2: Figure showing the trends of the groundwater levels between 1983 and 2007...... 63 Figure 5-3: Shows trends of the groundwater levels between 2014 and 2018...... 64

TABLES

Table 4-1: Total number of Prosopis at each locality, total plots sampled, and the density of Prosopis sampled along the Fish and Orange River...... 21 Table 4-2: Other species that co-existed with prosopis and their percentage ...... 29 Table 5-1: Estimated water uptake by Prosopis in the Fish River per annum ...... 64 Table 5-2: Estimated water uptake by Prosopis in the Fish River per annum ...... 65

BACKGROUND AND INTRODUCTION

Introduction

The Orange-Senqu River Commission (ORASECOM) was established by the riparian States, which area Lesotho, South Africa, Botswana and Namibia, for effective development and management of the water resources of the Orange- Senqu River Basin for the benefit of all the people in the four countries.

ORASECOM, with support from the United Nations Development Programme (UNDP), managed to secure financial support from the Global Environment Facility (GEF) to implement selected priority activities of the Strategic Action Programme (SAP). The UNDP-GEF SAP project is addressing the barriers to sustainable development/management of the basins water and related resources which were identified through the Transboundary Diagnostic Analysis (TDA). The project is the strengthening joint management capacity of basin stakeholders for implementation of the basin-wide Integrated Water Resources Management (IWRM) Plan and demonstrating environmental and socioeconomic benefits of ecosystem-based approach to water resources management.

Specific to Namibia, the project is supporting the Government of Namibia to address causes of land degradation that is related to alien invasive species, Prosopis, in the Orange-Fish River Basin which forms part of the larger Orange- Senqu River Bain. Communities in the Orange-Fish River Basin largely use groundwater, estimated at 13.81 Mm3/a (ORASECOM, 2014). Prosopis invasion poses a threat to water supply in the basin as it is seen to reduce groundwater levels. In order to address the adverse effects of land degradation in the Orange- Fish River Basin, ORASECOM UNDP/GEF is supporting Namibia to enhance understanding on the environmental impacts of Prosopis and to implement integrated management measures for the control of this invasive alien species.

The assistance is aimed at applying lessons and experiences learned from the Working for Water Programme which was established in 1995 with the objective of addressing the threat of invasive alien species in South Africa at a large scale. Up to 1,500 ha were cleared annually with an additional 4,000 ha of already cleared areas treated. The Namibia demonstration project will adopt lessons learned from this programme as well as other projects implemented locally. Terms of Reference (ToR)

Tortoise Environmental Consultants were contracted by The Orange Senqu River Commission (ORASECOM) UNDP/GEF, to undertake a Baseline Study on distribution and abundance of alien invasive species, specifically Prosopis in the Orange - Fish River Basin in Namibia. The baseline study is required:

1 a) To inform a sustainable business venture based on harvesting of Prosopis (which may include firewood, charcoal etc) to be set up by the ORASECOM UNDP/GEF Project. b) To propose groundwater monitoring plan which will be used to quantify the long-term impacts of Prosopis on the groundwater resources.

Objectives

The study objectives are as follows:

a) To conduct a baseline study on the distribution and abundance of Prosopis in the Orange – Fish River Basin in Namibia. b) Outline lessons learned from previous projects aimed at controlling Prosopis; notably the Working for Water Programme in South Africa and other projects in Namibia (Gibeon and /Ai-/Ais project). The review should put emphasis on the challenges, success and sustainability to guide potential business development ventures (fire wood, fodder, charcoal, furniture, etc) c) To develop a monitoring plan for groundwater levels in order to quantify the impacts of Prosopis.

Scope of the study as outlined in the ToR

i. Conduct an inventory of Prosopis in the Orange and Fish Rivers and their tributaries and document abundance and density of the Prosopis;

ii. Conduct feedback session and training of government officials on methodologies for evaluation of presence and extent of Prosopis;

iii. Produce maps showing distribution and density of Prosopis;

iv. Draw up a monitoring plan for identifying trends in groundwater level and biodiversity changes;

v. Working with the relevant authorities, implement monitoring stations and monitor water levels in both infested and non-infested areas (as control);

vi. Carry out studies to determine/quantify the impacts of Prosopis on surface water and groundwater resources, biodiversity and general infrastructure.

Deliverables

Outputs/deliverables from the study include:

2 i. Report on inventory of Prosopis in the Orange and Fish Rivers and their tributaries with the associated maps showing distribution and density; ii. Training reports and materials on methodologies for evaluation of presence and extent of Prosopis; iii. Monitoring plan for groundwater level and biodiversity changes and; iv. A detailed report on findings, conclusions and recommendations on the impacts of Prosopis on groundwater resources v. Proposal for a community project to manage Prosopis

STUDY AREA

The Orange – Fish River Basin

The baseline study was conducted in the Orange-Fish River Basin which covers an extensive area of approximately 120,000 km2 of the southern part of Namibia 120,000 km2 (Figure 2.1). The Orange-Fish River Basin covers 15% of Namibia’s surface area, making it one of the largest basins in the country, as such environmental and socio-economic aspects such as that of Prosopis require urgent holistic management interventions.

The Fish and Orange Rivers are the main rivers in Namibia that contribute to surface water flow of the Orange-Senqu River Basin, with the Fish river being the tributary to the greater Orange-Senqu river. The Fish River originates in the Rehoboth plateau north-west of Maltahöhe, and flows initially in a northerly and then in a southerly direction towards the perennial Orange River. The confluence of both rivers is some 35 km south-west of /Ai-/Ais within the /Ai-/Ais–Richtersveld Transfrontier Park. In some areas, mostly along the eastern basin margin, the boundary deviates slightly from the surface water catchment, where groundwater basins and geological formations are considered to be more critical criteria for the definition of the basin (DWAF, 2004).

The Orange–Fish River basin covers areas of two administrative regions, namely: //Karas and Hardap. Approximately 77,000 people live in the Orange–Fish River basin representing 56 per cent of the population of Hardap and //Karas regions (ORASECOM, 2014). In the Hardap and //Karas regions, 46 per cent and 54 per cent of the population respectively, are classified as living in urban areas. In general, 72.4 per cent of the Orange–Fish River basin is privately-owned freehold land, while only 14.8 per cent falls under traditional authority (communal lands).

Furthermore, 11.2 per cent of the basin is state-owned land while only 1.6 per cent is represented by the local authorities. A major part of communally owned land in Hardap and //Karas regions lies within the Orange–Fish River basin, while poor informal settlements on townlands surround each of the urban centres (ORASECOM, 2014).

Figure 2-1: The Study Area – Orange Fish River Basin

METHODOLOGY

Methodology

The general approach for the baseline study entailed literature reviews, interviews with key stakeholders who are involved in Prosopis projects in Namibia and groundwater monitoring, field survey, documentation and reporting. Below is a presentation on the detailed approach, programme work and methodologies that were used during the baseline assessment.

Mapping of the distribution and density of Prosopis

Mapping of the Prosopis distribution and density has been captured for each habitat type/sample site using QGIS Valmeira Edition (QGIS, 2014).

Satellite data inputs include Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 5 Thematic Mapper (TM) imagery were downloaded1. Both Landsat archive data and Global Land Survey (GLS) data were used. All images with cloud cover less than 50% Landsat scene footprints covering Orange-Fish River Basin were selected and downloaded.

Images were resampled to a 60 m spatial resolution to reduce false change detection due to residual mis-registration effects. To remove cloud/cloud shadow affected observations, a per-pixel quality assessment was implemented using a set of pre-defined cloud/cloud shadow detection rules.

Stratums were identified by visual interpretation. Upon completion of the mapping, the area of each stratum was calculated and corresponding sample plots were demarcated. Depending on the practical consideration in the Orange-Fish River Basin, a sampling intensity of 5-10% was used.

Identification of sample sites and plots

Satellite images (referenced in the footnote) were downloaded to map the Orange-Fish River and its tributaries. The images were processed using standard image processing techniques. The images were classified and stratums were delineated. Depending on the sizes of the strata, representative sample sites and plots were laid out for the evaluation of Prosopis abundance and density.

1 US Geological Survey National Center for Earth Resources Observation and Science via the GLOVIS data portal (http://glovis.usgs.gov/) 6

Stratified sampling was used to increase the precision of abundance and density estimates. In this case, sample plots were allocated to strata in proportion to the strata sizes. Classified maps and sample site and plot location were printed and used during the field work.

A total number of six (6) localities were sampled within the Fish River, and another six (6) localities from the Orange River. In-addition, the intersection of the two (2) rivers was also sampled, bringing the total number of samplings sites to thirteen (13) as presented below:

• #1_Maltahohe (Nomstas)

• #2_Hardap dam

• #3_Gibeon

• #4_Berseba

• #5_Neckartal dam

• #6_/Ai/-Ais National Park

• #7_Orange – Fish Intersection

• #8_Senderlingsdrift

• #9_Oranjemund (Op my stoep)

• #10_Aussenkehr

• #11_Noordoewer

• #12_Farm Sonop

• #13_Oana Nature Reserve

Figure 3-1: Sampling Sites for Prosopis distribution and density in the Orange – Fish River Basin (Author, 2020)

In order to fully understand the spatial and temporal patterns of Prosopis density and abundance, thirteen (13) study sites were identified and sampled along the Fish and Orange Rivers. For each sampling site two (2) transects were laid out, with each transect consisting of Twenty (20) plots and each plot measures 10 m x 10 m = 100 m2 x 20 = 2,000 m2 per site x 13 sites = 26,000 m2. Meaning, a total surface area of 26,000 m2 was sampled across the Fish and Orange Rivers as illustrated in (Figure3.3).

The position of the sample sites and plots were marked using a GPS and the general landscape and habitat features of each site were described and photos were taken.

In order to understand the vegetation heterogeneity across the river, transects were established across the three main river habitats, namely; north bank, watercourse or riverbed and south bank. However, in the Orange River transect were only installed on the north bank, due to inability to access the watercourse or riverbed and of the south bank.

Figure 3-2: Sampling Transects, Site #1 Maltahohe – Nomstas, Fish River (Author, 2020).

To ensure that an inclusion of several important aspects of various habitat types i.e. floodplain, riverine etc. were determined and equally represented in the assessment, therefore, a representative number of plots were set out in each habitat type at different localities to ensure high level of accuracy. The belt transects were demarcated perpendicular to the river, but parallel to each other at a distance of 100 m.

Figure 3-3: An illustration of how the transects and plots were demarcated for along the Fish and Orange Rivers.

Assessments of Prosopis abundance and density

In order to determine the abundance and density of Prosopis in the Orange-Fish River Basin, the Braun-Blanquet Method was used. In each sample site, transects were demarcated and plots were set up (Kent, 2012; Strohbach, 2001). An important aspect was to ensure that various habitat types i.e. floodplain, riverine etc are determined and equally represented in the assessment, therefore, a representative number of plots were set out in each habitat type to ensure high level of accuracy. The belt transects were established perpendicular to the river, but parallel to each other at a distance of 100 m.

Within each plot, plant species (including Prosopis) were identified and recorded using general identification guides (Mannheimer & Curtis, 2009; Mannheimer, 2012; Müller, 2007). For each recorded species within each plot, the following was noted:

1) the typical growth form, 2) height, 3) stem diameter, and 4) an estimated canopy cover

The rationale for recording all the plant species within each plot was to enable determination of the potential impacts of Prosopis on the diversity of other plant species or communities in the Orange-Fish River Basin.

Furthermore, for each matured Prosopis observed, the number of stems were noted as single or multi-stem or counted where it was possible. Grass cover was also recorded in each plot by estimating the percentage (%) cover or bare for each quadrat or plot.

The data will be submitted to the Directorate of Forestry for capturing in the National Forest Inventory database. This will present an opportunity for incorporation of the collected data into the national database to form the basis for long term monitoring of plant diversity in the Orange- Fish River Basin.

Assessment of the impacts of Prosopis on biodiversity of plant communities

In addition to identification of woody species within the plots, the herbaceous plant species were also identified and recorded. The Simpson's diversity index was used to calculate/determine the impacts of Prosopis on the diversity of other plant communities in the Orange-Fish River Basin. This made possible to identify indigenous plants that might be affected by Prosopis infestation and to recommend management measure.

Figure 3-4: Marking a 10m quadrant (plot) across the Fish River at Nomstas in Maltahohe,

Figure 3-5: Marking a 10m quadrant (plot) along the Orange River at

Figure 3-6: Marking of Plots using measuring tapes through dense Prosopis infestation

Figure 3-7: Navigating through dense Prosopis infestation during the baseline assessment

Figure 3-8: Taking measurement of Diameter at Breast Height (DBH) using the Callipers in the plots.

Figure 3-9: Identification and record of flowering Prosopis plants

Figure 3-10: Determining height of the Prosopis trees using the human height methodology, where an identified individual’s height is measured and he/she stands at the bottom of the tree while another person moves 30-40 meters away to estimate how many of the individual makes the entire tree to the top.

Figure 3-11: Count and recording of seedlings in the plots, as an indication of regenerative growth within the plots and areas.

Figure 3-12: Prosopis Regrowth after harvesting

Observation of Prosopis regrowth at Gibeon, after harvesting for firewood and charcoal. This implies that follow up activities are required after harvesting, otherwise it will not be sustainable, as the tree is known to evolve and hybridize in response to disturbance.

Data Capturing analysis

Raw data was entered into excel sheets from the field record hard copies. The data was then cleaned further using hard copies and field experience for quality control and the descriptive statistics was analysed by using Microsoft Excel. Graphs and tables were generated from the analysed data with the use of Microsoft Excel and SPSS.

Furthermore, inferential statistics to test for the significant differences between the Prosopis density and abundance between the Fish and Orange Rivers as well as among the study locality or towns was subjected to the One-Way Analysis of Variance by using SPSS Statistical software tools.

Training on methodologies for evaluating the presence and extent of Prosopis

The methodology for evaluating the presence and extent of Prosopis in a catchment area was developed prior to the field activities, as described in section 3.1 (b). The methodology adopted involved comparisons between different approaches of measuring plant distribution and densities (Annex 1 Training Manual.

Due to travel restrictions imposed by the Government in response to the outbreak of COVID-19, only one government official from the Department of Water Affairs/Basin Management and eight recent graduates from Namibia were able to participate in the hands-on field training on evaluating the presence and extent of Prosopis. The methodology for assessment is documented and may be used in future studies.

All the participants gained valuable knowledge and practical skills to support future surveys. The methodology for assessment was updated after the filed surveys to incorporate experiences and lessons learned in the field.

INVENTORY OF PROSOPIS IN THE ORANGE-FISH RIVER BASIN

Introduction of Prosopis to Namibia

Prosopis species were introduced to Namibia as early as 1897 for shade and as a fodder tree for domestic animals such as cattle, donkeys, horses, goats and sheep (Smit 2005) and has since aggressively invaded riverine systems throughout the arid and semi-arid parts of Namibia and southern Africa (Brown et al. 1985; Henderson 2001; Bethune et al. 2004; Smit 2005; van den Berg 2010). Since then, its densities have increased significantly and thereby taking over most of the ephemeral watercourses in central and southern Namibia, including the Orange and Fish Rivers. Namibia has 3 Prosopis species, with Prosopis glandulosa (honey mesquite) being the most occurring species and is mostly found along riverbeds and dry water courses

Literature has widely published the impact of invasive species on the economic, social and ecology systems (Liba and Gretchen 2009, Stefan 2005). Invasive alien species out-compete native species for food and habitat and interrupts the natural functioning of ecosystems. Prosopis plants are considered to have a more adverse ecological impact than all other alien plants in Namibia (ORASECOM, 2014).

According to Zeray et al (2017), Prosopis is one of the world’s worst invasive alien species, causing severe environmental degradation to the arid and semi-arid areas in Africa, hence threatening the livelihood and food security of pastoral and agro-pastoral communities. Unlike most indigenous species, Prosopis has extensive tap root system (depths of >50m), an ability which has potential to lower the water table and hence reduce the amount of water which is available for other plants (desirable grazing plants and indigenous tree species).

This consequently affects the productivity of other vegetation and reduce borehole yields (Nilsen et al., 1983; Ansely, Boutton and Jacoby, 2007). Prosopis prevents groundwater infiltration and recharge and in areas of dense growth it also impedes surface flow, which is why the species is believed to use a lot of groundwater. Prosopis also is also seen to reduce the aesthetic value and biodiversity of the areas it invades.

According to Le Maitre (1999), one Prosopis tree uses about 50 litres of water per day. A study done by Ntesa et al. (2014) on the distribution and abundance of Prosopis in the Fish River (upper stream) estimated that one Prosopis tree that is taller than 8m uses about 27.6 litres of water per day.

It is therefore crucial to determine/quantify the impacts of Prosopis on surface water and groundwater resources in different environments in order to inform policy formulation processes in the country.

Results on the distribution and density of Prosopis in the Fish-Orange Basin

The results in this section were obtained from the analysed data, and these were determined and selected based on the two objectives of the project; namely the abundance (distribution) and density of the Prosopis invader.

The results in the following section are therefore, interpreted as a result of the abundance (distribution) and density of the Prosopis trees and seedlings along the entire rivers and also as sections of the rivers depending on the sampling localities.

Table 4-1: Total number of Prosopis at each locality, total plots sampled, and the density of Prosopis sampled along the Fish and Orange River. Number of plots Total area Number of Site (River) Locality sampled (ha) individual (N) Density (N/ ha) Nomstas Farm- Fish River Maltahohe 57 0.57 19 33.33333 Fish River Hardap Dam Farm 32 0.32 18 56.25 Fish River Gibeon 41 0.41 32 78.04878 Fish River Berseba 17 0.17 0 0 Fish River Ai-Ais National Park 17 0.17 13 76.47059 Fish River Neckartal 24 0.24 20 83.33333 Orange River Aussenkehr 39 0.39 16 41.02564 Fish-Orange River intersection Fish River mouth 43 0.43 4 9.302326 Orange River Rosh Pinah 5 0.05 0 0 Orange River Oop my Stoep 53 0.53 3 5.660377 Orange River Oana nature reserve 39 0.39 145 371.7949 Rosh Pinah- Orange River Sendelingsdrift mine 6 0.06 1 16.66667 Orange River Noordoewer 43 0.43 60 139.5349 TOTAL 416

Overall abundance and density of Prosopis in the Fish and Orange Rivers

Overall, the density for the Fish and Orange Rivers appears to be the same, with 454 trees recorded per hectare in the Fish River and 431 trees per hectare in the Orange River. Similarly, the numbers of seedlings per hectare are about the same in the two rivers.

Figure 4-1: Total density of Prosopis trees per hectare in the Fish and Orange River

Figure 4-2: Density of Prosopis seedlings/saplings in the Fish and Orange Rivers

Abundance and density of Prosopis in the Fish River

The highest Prosopis densities were recorded at Neckertal, Gibeon and Hardap Dam Farm. An interesting observation was that the number of seedlings per hectare were observed to be low at Neckertal, unlike the other two sites with high densities.

Figure 4-3: Total density of Prosopis trees per hectare across the six (6) locality/towns in the Fish River

Figure 4-4: Density of Prosopis seedlings/saplings in the Fish River

Abundance and density of Prosopis in the Orange River

In the Orange River, the highest Prosopis densities were observed at Noordoewer and Sonop farm. However, these two sites recorded lower numbers of seedlings per hectare. High numbers of seedlings were recorded at Oana Nature Reserve and Aussenkehr.

Figure 4-5: Total density of Prosopis trees per hectare across the six (6) sites located in the Orange River

Figure 4-6: Density of Prosopis seedlings/saplings in the Orange River

Abundance of Prosopis Seedlings in the Fish and Orange Rivers

Figure 4-7 – Abundance of Prosopis seedlings/saplings in the Fish River

Figure 4-8 – Abundance of Prosopis seedlings/saplings in the Orange River

Height and canopy cover of Prosopis in the Fish and Orange Rivers

Figure 4-9 – Average height of Prosopis in the Fish and Orange River.

Figure 4-10 – Average height of Prosopis in the Fish River.

Figure 4-11 – Average height of Prosopis in the Orange River.

In terms of the landscape management purpose of the invasion of Prosopis in the Fish and Orange Rivers, it is pivotal to understand the relationship between the tree height and canopy area to quantify aboveground biomass. It appears that taller Prosopis trees have a larger canopy cover across the two rivers as indicated in 5.12).

On average, the Orange River had Prosopis trees with larger canopy cover (42.6 m) and shorter (5.4 m) trees, when compared to the Fish River that had much smaller canopy cover (31.0 m) and slightly taller (6.2 m) trees. Prosopis water-relation and its implication on the groundwater is still unclear, especially in the drylands with unpredictable and variable rainfall patterns. Therefore, better landscape management should be developed through in situ research and monitoring of impacts of Prosopis on the socio-economic and environment.

Figure 4-12: Relationship between Prosopis height and canopy area in the Fish and Orange River

Health conditions of Prosopis in the Fish and Orange Rivers

To understand the health condition of the Prosopis in the Fish and Orange Rivers, condition scoring was estimated by observing the general plant characteristics of the green pigment as a representative of its physiological status. Both rivers indicated variations in the Prosopis health status (Figure 5.13).

Overall, the health status of the Prosopis trees along the two rivers was observed to be good, especially around Gibeon and Noordoewer (Figure 5.13), however, quantification of the physiological parameters such as the photosynthetic efficiency and water potential is highly recommended.

Figure 4-13: Health condition scoring along the Fish and Orange Rivers

Number of Prosopis in relation to Other Species

Table 4-2: Other species that co-existed with prosopis and their percentage

No. Other spp. Frequency % 1 Acacia fleckii (AF) 59 46.09 2 Unidentified shrubs (US) 22 17.19 3 Acacia tortilis 2 1.56 4 Ziziphus mucronata (ZM) 4 3.13 5 Acacia fleckii and shrubs 1 0.78 6 Salt tolerant shrub 1 0.78 Acacia fleckii + Euclea 7 psuedebenus 1 0.78 Acacia fleckii + Ziziphus 8 mucronata 1 0.78 9 Euclea psuedebenus (EP) 2 1.56 Euclea psuedebenus + 10 Acacia fleckii 1 0.78 11 Shrubs 1 0.78 12 EP + AF+Tamarix usneoides 1 0.78 13 Tamarix Usneoides (TU) 20 15.63 14 Argemone Mexicana 1 0.78 15 Vachellia erioloba 1 0.78 16 Shrubs 1 0.78 17 Segde grass 3 2.34 18 Sedge bush 2 1.56 19 Salt bush (SB) 1 0.78 20 EP + ZM + SB 1 0.78 21 ZM + EP + Tamarix Usneoides 1 0.78 22 TU + US 1 0.78 Total 128 100.00

A total of 22 species co-existed with Prosopis. The dominant specie was Acacia fleckii (46 %) followed by some unidentified shrubs (17.19 %). In some places a combination of other species was observed, for example Ep, Zm, Tu.

30 Prosopis Quantity

0 1 9 17 25 33 41 49 57 65 73 81 89 97 105 113 121 129 137 145 153 161 169 177 185 193 201 209 217 225 233 241 249 Figure 4-14: The graph illustrates the relationship between no. of Prosopis vs other species

• Where there is a low number of other species present, the area is dominated by the invasive species (Prosopis) and vice versa. • Where: Quantity = Total number of other species.

Data Interpretation

This section discusses the above presented results, with special focus on the abundance (distribution) and density of the Prosopis plant species and seedlings along the entire rivers as well as the sections of the rivers depending on the sampling localities.

Distribution and abundance of Prosopis

The abundance/distribution of Prosopis plant species was observed to be higher in the Orange River than in the Fish River (Table 1). A total of172 individual Prosopis tree were counted during the exercise. The Sonop farm acounted for the highest number of tree counts, while Sendlingsdrift accounted for the lowest tree count along the Orange River. On the Fish River part of the basin, only 96 individual Prosopis trees were counted, with Nomstas recording the highest number of tree counts and Berseba recording no Prosopis species.

In some areas such as the Sonop Farm access through the extremely dense Prosopis thicket was impossible because the canopy cover was 100% (for a stretch of more than 200m). This gives some early indications of the possibility of high abundance of Prosopis infestation on the Orange River part of the basin. It could also highlight a potential negative effect in terms of limiting the quantity of water flow downstream of the river.

This result could probably be due to the differences in the rivers characteristics and management approaches and interventions. Prosopis management initiattives from either Goverments or communities have been reported along the two rivers, where the trees are cut down for either firewood, Charcoal, and funiture, however, they could be more effective along the one river than the other.

Prosopis Seedlings

The highest number of Prosopis seedlings on the Orange River were recorded in the Oana nature reserve (N= 315) followed by Aussenkehr (N= 138) and the least recorded in the Noordoewer (N= 10). In some areas (Sonop farm, Roshpinah, Rosh Pinah- Sendelingsdrif mine and Close to Orangemund) no seedlings of Prosopis were observed (Figure 10 & 11).

On the parts of Fish River, Prosopis seedlings were more abundant in the Nomstas Farm- Maltahohe and Gibeon with (N = 88) and (N = 64) respectively. Berseba, Ai-Ais and Neckartal recorded the least Prosopis seedlings. No seedling of Prosopis were recorded in the Hardap Dam Farm. The high number of Prosopis saplings in both Oana and Nomstas can be associated with the prescence of more mature trees at both sites. It can therefore be inferred that the reproduction of these plant species is high, where mature trees are present and were no sort of management or control measures are taken. The low presences of seedling regeneration in the Fish River part of the basin can be attributed to effective control/management strategies appliead. This can be further attributed to insufficient or poor rainfall conditions in the Fish River, resulting in less favourable conditions for regeneration compared to the Orange River part of the basin.

Variations

Variations in the density of Prosopis trees and seedlings/saplings were observed among the sampled localities/towns within each river as indicated in Figure Table 1, which appears to be attributed to the specific management practices at this specific areas.

In the Fish River, the highest density of Prosopis was recorded at Nerkatal dam, whereas, Berseba recorded zero trees. While along the Orange River the density was highest at, farm Sonop, Oana Nature Reserve and Noordower whlist this was also the result of the density of seedlings respectively.

In terms of other species identified in the quadrants/plots, aproximately 22 other plant species were found to coexist with Prosopis along the river basins. The dominant species were Acacia fleckii (46 %) followed by some unidentified shrubs (17.19 %). In some places, a combination of other species were observed, for example Ep,Zm,Tu (Table 2).

Relationship with other Species

A relationship between the numbers of Prosopis vs other species was also studied (Figure 16). The general observation is that there is comparatively low presence of other plant species in parts with moderate to high Prosopis infestation.

This study observed that some areas had more of the other tree species than the invader Prosopis species. It however cannot be concluded that the presence of other species was the result why Prosopis species were in low numbers or not present at all. This study focused only on attributes that would contribute to the determination of the relations resulting in abundance and density of Prosopis.

Prosopis Distribution and Abundance Maps – Overall Maps Entire Orange – Fish Basin Distribution and Density of Prosopis in the Fish & Orange Rivers 15°0'0"E 16°0'0"E 17°0'0"E 18°0'0"E 19°0'0"E 20°0'0"E 21°0'0"E 24°0'0"S !HKalkrand 24°0'0"S

!HMariental Maltahöhe ¥ !H

25°0'0"S 25°0'0"S !H Gibeon

0 45 90 180 Kilometers

Tses Scale 1:3,000,000 Berseba !H 26°0'0"S !H 26°0'0"S Prosopis Distribution !H Localities Bethanien !H Keetmanshoop !H Bare Land !HGoageb / Konkiep Very Low Low 27°0'0"S 27°0'0"S Moderate High Very High !HGrünau Ai Ais Rosh Pinah !H !H Karasburg 28°0'0"S !H 28°0'0"S !H !HAriamsvlei Fish-Orange Confluence

!H Aussenkhr Orangemund !H Warmbad !H Noordoewer Prosopis Distribution Distance (km) Area (ha) Count !H Bare Land 504.76 22799.73 4 Very Low 68.40 3056.24 4 29°0'0"S Low 38.38 1718.23 3 29°0'0"S Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

15°0'0"E 16°0'0"E 17°0'0"E 18°0'0"E 19°0'0"E 20°0'0"E 21°0'0"E

Distribution and Density of Prosopis in the Fish & Orange Rivers 15°0'0"E 16°0'0"E 17°0'0"E 18°0'0"E 19°0'0"E 20°0'0"E 21°0'0"E 24°0'0"S !HKalkrand 24°0'0"S

!HMariental Maltahöhe ¥ !H

25°0'0"S 25°0'0"S !H Gibeon

0 45 90 180 Kilometers

15°0'0"E 16°0'0"E 17°0'0"E 18°0'0"E 19°0'0"E 20°0'0"E 21°0'0"E 34

Fish River Section Distribution and Density of Prosopis in the Fish River 15°0'0"E 16°0'0"E 17°0'0"E 18°0'0"E 19°0'0"E 20°0'0"E

24°0'0"S 24°0'0"S !HKalkrand

Mariental !H ¥

!HMaltahöhe Prosopis Distribution 25°0'0"S 25°0'0"S Gibeon !H Localities !H 0 40 80 160 Kilometers Bare Land

Very Low Scale 1:2,500,000 Low Moderate !HTses High Berseba 26°0'0"S !H 26°0'0"S Very High

Bethanien !H Keetmanshoop !H Goageb / Konkiep !H

27°0'0"S 27°0'0"S

Grünau Prosopis Distribution Distance (km) Area (ha) Count !H Bare Land 504.76 22799.73 4 Ai Ais Very Low 68.40 3056.24 4 Rosh Pinah !H !H Karasburg 28°0'0"S Low 38.38 1718.23 3 28°0'0"S !H Ariamsvlei Moderate 132.19 5403.95 8 !H !H High 68.80 2963.70 3 Fish-Orange Confluence Very High 131.30 5737.43 3 Total 944.25 41679.27 25 !H 15°0'0"E 16°0'0"E 17°0'0"E 18°0'0"E !H 19°0'0"E 20°0'0"E

Orange River SectionDistribution and Density of Prosopis in the Orange River 17°0'0"E 18°0'0"E 19°0'0"E 20°0'0"E

Prosopis Distribution Distance (KM) Low 48.07 Medium 77.20 High 28.05 ¥ Grünau Very High 615.00 H!

Ai Ais Rosh Pinah H! H! 28°0'0"S Karasburg H! 28°0'0"S Fish-Orange Confluence H! Ariamsvlei H!

Aussenkehr H! Warmbad H! Oranjemund H!

Noordoewer H!

29°0'0"S 29°0'0"S Prosopis Distribution

H! Localities Very Low Low

Moderate 0 25 50 100 Kilometers High Very High Scale: 1:580,000

17°0'0"E 18°0'0"E 19°0'0"E 20°0'0"E

Prosopis Distribution and Abundance Maps – Fish River Sub-sections Fish River – Very high Density .! Fish River (Very High Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Scale Keetmanshoop 1:20,000 .!

0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

.! Fish River (Very High Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Scale Keetmanshoop 1:20,000 .!

0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

Figure 4-15: Fish River – Prosopis Distribution – Very high density

Fish River – High Density .! Fish River (High Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Scale Keetmanshoop 1:20,000 .!

0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

.! Fish River (High Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Scale Keetmanshoop 1:20,000 .!

0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

Figure 4-16: Fish River – Prosopis distribution – High density sections

Fish River – Moderate Density .! Fish River (Moderate Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop Scale 1:20,000 .! 0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

.! Fish River (Moderate Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop Scale 1:20,000 .! 0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

Figure 4-17: Fish River – Prosopis distribution – Moderate density

Fish River – Low Density .! Fish River (Low Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop .! Scale 1:20,000 0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

.! Fish River (Low Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop .! Scale 1:20,000 0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

Figure 4-18: Fish River – Prosopis distribution – Low density

Fish River – Very Low Density .! Fish River (Very Low Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop Scale 1:20,000 .! 0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

.! Fish River (Very Low Density) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop Scale 1:20,000 .! 0 0.25 0.5 1 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

Figure 4-19: Fish River – Prosopis distribution – Very Low density

Fish River – Bare Land .! Fish River ( Bare Land) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop Scale 1:30,000 .! 0 0.375 0.75 1.5 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

.! Fish River ( Bare Land) ¥ Mariental .! Prosopis Distribution ! . Localities Maltahöhe .! Bare Land Very Low Low Gibeon Moderate .! High Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very High Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Tses .! Berseba .!

Bethanien .! Keetmanshoop Scale 1:30,000 .! 0 0.375 0.75 1.5 Kilometers Goageb / Konkiep .!

Scale 1:1,700,000

0 25 50 100 Kilometers

Figure 4-20: Fish River Prosopis distribution – Bare Land

Fish – Orange River Confluence (Low – High density)

Fish- Orange River Confluence (Low - High Density) Tses !. Berseba Prosopis Distribution !. ¥ !. Localities Bare Land Very Low Low

Moderate Bethanien !. Keetmanshoop High !. Very High River Goageb / Konkiep !.

Prosopis Distribution Distance (km) Area (ha) Count Bare Land 504.76 22799.73 4 Very Low 68.40 3056.24 4 Low 38.38 1718.23 3 Moderate 132.19 5403.95 8 High 68.80 2963.70 3 Very High 131.30 5737.43 3 Total 944.25 41679.27 25

Grünau !. Scale 1:20,000

Rosh Pinah !. Ai Ais !. Karasburg !. !. Fish-Orange Confluence

Aussenkehr 0 0.2 0.4 0.8 Kilometers !. Warmbad Scale 1:1,700,000 !. Oranjemund !. 0 25 50 100 Kilometers

Fish- Orange River Confluence (Low - High Density) Tses !. Berseba Prosopis Distribution !. ¥ !. Localities Bare Land Very Low Low

Moderate Bethanien !. Keetmanshoop High !. Very High River Goageb / Konkiep !.

Grünau !. Scale 1:20,000

Rosh Pinah !. Ai Ais !. Karasburg !. !. Fish-Orange Confluence

Aussenkehr 0 0.2 0.4 0.8 Kilometers !. Warmbad Scale 1:1,700,000 !. Oranjemund !. 0 25 50 100 Kilometers

Prosopis Distribution and Abundance – Orange River Sub-sections Orange River – Very high Density &3Aussenkehr Orange River (Very High Density)

Warmbad &3 ¥

Noordoewer &3

Prosopis Distribution Distance (KM) Low 48.07 Medium 77.20 Prosopis Distribution High 28.05 Very High 615.00 &3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.25 0.5 1 Kilometers Very High 0 5 10 20 Kilometers

&3Aussenkehr Orange River (Very High Density)

Warmbad &3 ¥

Noordoewer &3

Figure 4-21: Orange River – Prosopis distribution – Very high density

Orange River – High Density

Orange River (High Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.325 0.65 1.3 Kilometers Very High 0 5 10 20 Kilometers

Orange River (High Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.325 0.65 1.3 Kilometers Very High 0 5 10 20 Kilometers

Figure 4-22: Orange River – Prosopis distribution – High density

Orange River – Moderate Density

Orange River (Moderate Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.325 0.65 1.3 Kilometers Very High 0 5 10 20 Kilometers

Orange River (Moderate Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.325 0.65 1.3 Kilometers Very High 0 5 10 20 Kilometers

Figure 4-23: Orange River – Prosopis distribution – Moderate density

Orange River – Low Density

Orange River (Low Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3 .!

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.25 0.5 1 Kilometers Very High 0 5 10 20 Kilometers

Orange River (Low Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3 .!

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.25 0.5 1 Kilometers Very High 0 5 10 20 Kilometers

Figure 4-24: Orange River – Prosopis distribution – Low density

Orange River – Very Low Density

Orange River (Very Low Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.25 0.5 1 Kilometers Very High 0 5 10 20 Kilometers

Orange River (Very Low Density) Fish-Orange Confluence &3 ¥

Prosopis Distribution Distance (KM) Low 48.07

Medium 77.20 Aussenkehr High 28.05 &3 Very High 615.00

Oranjemund &3

Noordoewer &3

Prosopis Distribution

&3 Localities Very Low Low Moderate High Scale: 1:20,000 Scale: 1:500,000 0 0.25 0.5 1 Kilometers Very High 0 5 10 20 Kilometers

Figure 4-25: Orange River – Prosopis distribution – Very Low density

GROUND WATER MONITORING PLAN

Excessive Water Use

It has been well documented and understood that Prosopis use significant amounts of water and has the ability to lower the water tables. In order to measure the impact of Prosopis on ground water, monitoring boreholes are recommended for the highly infested river sections, and control boreholes are recommended for non-infested river sections.

Studies in South Africa has indicated that, Acacia erioloba density decreases due to Prosopis invasion, possibly due to excessive water abstraction leading to the lowering of the water table (Le Maitre et. al. 1999).

Monitoring boreholes

The Ministry of Agriculture, Water and Land Reform (MAWLR) through its Department of Water Resource Management (DWRM) conduct periodic ground water monitoring exercise to monitor groundwater levels and develop trends for groundwater levels in the Orange – Fish Basin.

The groundwater monitoring boreholes were jointly constructed by the the ministry (DWRM) and Namwater at strategic locations across the country for, including the Fish and Orange River basins (Figure 5.1).

The groundwater monitoring boreholes have been mapped according to the following classifications (production, monitoring, and control). Monitoring boreholes will enable the authorities to establish trends and changes in groundwater levels over a period of time and guide the introduction and implementation of control measures.

Below is a presentation of groundwater monitoring data collected by DWRM between 1981 and 2017 from the monitoring boreholes within the basin. The data presents ground water trends in the Orange – Fish Basin as shown in figure 5.1 to 5.3 below.

Figure 5-1: Existing Ground Water Monitoring Boreholes in the Orange – Fish River Basin

Figure 5-2: Figure showing the trends of the groundwater levels between 1983 and 2007.

Figure 5.2 shows the data from borehole no: WW 20185 shows that there was a steady increase in groundwater levels from 1983 to 1990. However, between 1990 to 1991 the ground water levels dropped by approximately 1.2 m. There was a further notable increase of about 2m between 1991 and 1993.

From 1993 to 2000, the graph shows a fluctuating trend (increase and decline) of 1 – 1.2m per annum. The fluctuating ground water level trend presented in the graph above, could be a result of the inconsistent annual rainfall in the region.

In the year 2000, the graph shows a significant drop in the ground water level, where the ground water level dropped by about 6 meters, which seems to correlate to the severe drought recorded in that year (DWRM, 2001).

The last part of the graph representing years between 2001 and 2005 indicates a constant increase of less than a meter per year, and then about 1 m drop in 2006, but it seems to recover with another 1 m increase in 2007.

Figure 5-3: Shows trends of the groundwater levels between 2014 and 2018.

Figure 5.3 shows data from borehole no: WW 28844, which indicates a steady decline in ground level of about 4 – 6m between 2014 to 2018.

Water uptake and Impacts of Prosopis in the Orange – Fish Basin

The baseline assessment of Prosopis infestation (abundance and density) in both the Fish and Orange Rivers should form the baseline for future monitoring activities. It remains important to monitor the performance of the riparian vegetation and borehole yields in the basin.

Table 5-1: Estimated water uptake by Prosopis in the Fish River per annum Estimated water uptake by Prosopis in the Fish river Prosopis Average water Average water Average water Average tree uptake per tree uptake p/day uptake p/month water uptake Density p/ha p/day (L) (L) (L) p/year (L)

Very high 161 25 4,025 120,750 1,449,000

high 119 25 2,975 89,250 1,071,000

Low 37 25 925 27,750 333,000

Very low 19 25 475 14,250 171,000

Total 3,024,000

Table 5-2: Estimated water uptake by Prosopis in the Orange River per annum

Estimated water uptake by Prosopis in the Orange river Average water Average water Average water Average Prosopis uptake p/tree uptake p/day uptake p/month water uptake Density tree p/ha (L) (L) (L) p/year (L) Very high 167 25 4,175 125,250 1,503,000

Low 41 25 1,025 30,750 369,000 Very low 8 25 200 6,000 72,000

Total 1,944,000

Recommendation for a groundwater monitoring plan

The status of monitoring boreholes was assessed during the field surveys and recommendations for improvements were discussed with the relevant stakeholders (DWA, Basin Management Committee and NamWater). Based on this, a monitoring plan for identifying trends in groundwater level is recommended.

According to officials from the Ministry of Agriculture, Water, and Land Reform (MAWLR) the data collected on ground water monitoring could be further strengthened if the following measures were adopted:

• Adoption of a groundwater monitoring plan • Increase in human resources and training for effective and efficient data collection and processing. Refresher courses for staff who are involved in monitoring were recommended. • Monitoring in essence, is a very costly exercise. Thus, financial constraints also play a role, therefore, finances need to be sourced for better development and implementation of the plan. • It was recommended that basin officers could assist with collection of data if they receive the necessary training. Since they work at regional and local levels, they would be able to access monitoring boreholes which are located in remote areas. • Installation of protection cages to guard against damage of data collection devices installed at various monitoring boreholes • Acquisition and installation of boreholes with a technology that would allow for real-time data. • To increase the frequency of data collection from monitoring boreholes (e.g monthly / quarterly).

Recommendation for a groundwater monitoring plan

A groundwater monitoring plan is recommended to specifically enhance the understanding of the impacts of Prosopis on groundwater levels.

The following steps/actions are proposed for the ground water monitoring plan:

Establish baselines

i. Prioritize areas to be monitored, to include groundwater levels and Prosopis infestation. To kick-start the process, it is suggested that a pilot site should be identified where the monitoring would start. Site selection should be guided by:

• High Prosopis infestation • A site with established monitoring boreholes

ii. Establish control site(s) for monitoring. The control sites should have low Prosopis infestation and established monitoring boreholes.

iii. Establish baseline of groundwater levels (for groundwater monitoring)

Establish a groundwater monitoring schedule and analytical Programme

i. In consultation with the relevant stakeholders, establish monitoring schedules for groundwater levels. It is proposed that groundwater data should be collected frequently during the pilot phase. Furthermore, the schedule should also take into consideration rainfall patterns.

ii. Establish data management system, to include data analysis, storage and sharing.

iii. Set up the institutional arrangements for groundwater monitoring. It is proposed that DWA takes the overall lead in the implementation of the groundwater monitoring programme but the Department should liaise closely with the Basin office and basin stakeholders to ensure regular data collection. DWA and ORASECOM may also consider engagement of students and/or young professionals in the pilot phase of implementing the groundwater monitoring plan.

Implement groundwater monitoring Programme

i. Collect data according to the established schedule ii. Analyse data iii. Produce and disseminate reports iv. Monitor and review the effectiveness of implementation of the plan v. Produce lessons learned reports vi. Expand the plan across the basin, as necessary

Develop a groundwater simulation model

It is recommended that a groundwater simulation model should be conducted. The justification for using the model to inform the monitoring plan is sensible and that the system should be regarded as a tool to evaluate whether or not the predictions of the model are accurate. The groundwater simulation should be part of the project implementation, as an instrument / tool developed and recommended from the baseline.

To develop a groundwater monitoring plan, important lessons can be drawn from the groundwater monitoring plan Literature listed below,:

• Le Maitre, DC, Forsyth, GG, Dzikiti, S, Gush, MB, 2013. Estimates of the impacts of invasive alien plants on water flows in South Africa. Report No. CSIR/NRE/ECO/ER/2013/0067/B, Natural Resources and the Environment, CSIR, Stellenbosch.

• Van den Berg, EC, 2010. Detection, quantification and monitoring Prosopis spp. in the Northern Cape Province of South Africa using remote sensing and GIS. MSc in Environmental Science, Potchefstroom Campus, North-West University, Potchefstroom.

• Le Maitre, D. C., Versfeld, D. B., & Chapman, R. A. (2000). The impact of invading alien plants on surface water resources in South Africa: A preliminary assessment

• Le Maitre, D. C., Scott, D. F., & Colvin, C. (1999). Review of information on interactions between vegetation and groundwater.

PROSOPIS CONTROL PROJECTS

Review of previous and/or ongoing projects for clearing Prosopis

The objective of the baseline assessment was also to inform the design of a Prosopis control project which should be sustainable beyond the phase of the ORASECOM’s project. The envisaged Prosopis control project would involve communities in the clearing of trees for income generating such as firewood, charcoal etc., and contribute to the rehabilitation of the degraded areas of the Orange-Fish River Basin. The design of the new project draws on lessons learned from previous projects that were aimed at controlling Prosopis; notably the Working for Water Programme in South Africa and other projects in Namibia (Gibeon and /Ai-/Ais project). The focus of the review was on challenges, success and sustainability of such projects, to guide potential business development ventures (fire wood, fodder, charcoal, furniture, etc.). The review also contributed to the identification of Strengths, Weaknesses, Opportunities and Threats (SWOT) for the new project.

Working for Water Programme – South Africa

In South Africa, the Working for Water Programme which has been in implementation since 1995 is regarded as one of the most successful projects in addressing invasive alien species. The Programme is implemented by the Department of Environment and Fisheries (DEFF) and works in partnership with local communities, to whom it provides jobs, other government, research foundations and private companies. Since its inception in 1995, the Programme has cleared more than one million hectares of invasive alien plants providing jobs and training to approximately 20 000 people from among the most marginalized sectors of society per annum and with strong participation of women.

Gibeon and /Ais - /Ais Case Studies

Initiatives are also implemented in Namibia to curb the further of spread of Prosopis and other invasive species in Namibia. Prosopis harvesting projects were established in Gibeon and Ai-Ais with the ultimate aim of containing the rapid invasion of Prosopis and subsequently creating employment opportunities for community members residing in these areas.

Experience from the Gibeon, /Ai-/Ais and Leonardville Prosopis harvesting initiatives highlights that harvesting of Prosopis is relatively easy, however, the success thereof, depends on the continuous and consistent long-term harvesting and removal of seedlings, saplings and coppices.

• Strict adherence to the recommended clearing procedures (clearing of all plants, treatment with herbicides, follow-up treatments to remove seedlings, saplings and possible coppice, replanting of indigenous vegetation, and a regular monitoring programme) are essential for the successful removal of this alien invasive plant. In addressing this problem, it is essential to keep in mind that the stands of Prosopis are a threat to long-term water supply security, as this species is an excessive user of water (far more than indigenous vegetation). The long-term negative impact of these stands by far outweigh the short-term benefits of shade, fodder for animals and fuel- and timber wood.

• Considerable short-term direct financial benefits were generated by the community from the Gibeon Prosopis Clearing Project. Community members involved in the pilot project earned an average income of N$ 5,926.28 per person for the project duration. However, this does not portray a successful project because the income earned by individuals was in the form of remuneration from project funds and not based on the production output of their Prosopis harvesting efforts. In future, such practices should be discouraged because they do not motivate community members and may have a potential of creating a precedency, negatively affecting future projects that may not be in a position to pay honorarium. Non-financial and intangible benefits such as knowledge and skills have been enhanced as indicated, although there is still need for follow up given the low literacy rate in Gibeon.

• For the Ai Ais Prosopis Project, the community had to assist the project with tents, matrasses, tables etc. because as a small SME they did not have this equipment for starters. There was also a once off amount of N$ 9,000 for the fuel, so once this was done the company operated independently on the basis that they abide to park rules and also obliged to record everything they do from the entire process. There was only a total of seven employees on site and for the seven weeks. In the seven weeks they h managed to bag a total of 400 bags, (50kg/bag). The food and supplies always run out because it is a remote area, they also did not have adequate first aid supplies but that was supposed to be supplied by the company. There was a huge demand for firewood

in the south, for instance there were negotiations to sell of firewood to Namibia Wildlife Resorts (NWR) camps in the entire Southern NWR camps.

• Overall, during the course of the two pilot projects, constraints were encountered which diminished the complete realisation of the full economic potential from the harvesting and sale of Prosopis firewood in Gibeon and Ai Ais Richtersveld Transfrontier Park. The constraints include:

o lack of transport and storage facilities of harvested Prosopis firewood, limited business, management and leadership skills, o unclear payment models and delays in payments for the work done, o unequal distribution of labour which resulted in inefficient production rates, low prices of Prosopis firewood in the Namibia market, and o lack of project ownership among others. o In order to achieve socioeconomic goals of the project, the study team provides the following recommendations under each of the aspects outlined below.

• The success of any project very much depends on how well it is implemented. In the case of the Prosopis clearing project in Gibeon and Ai Ais, success would be determined by the extent to which the project contributes to the eradication of Prosopis in Gibeon and Ai Ais (Orange River) in order to restore water resources and biodiversity, while contributing to socio-economic development. These two projects did not manage to fully realise these objectives.

Recommendations for community Prosopis project

It is recommended that Namibia Demonstration Project to address Prosopis concentrates on strengthening the Gibeon community project for the following reasons:

o There is a good baseline on the infestation of Prosopis for the Gibeon area; o The community has been sensitized on the importance of addressing alien species, Prosopis in particular; o Some community members received training on harvesting Prosopis for firewood and marketing thereof; o The Gibeon Village Council has supported the Prosopis project in the past and could continue to provide leadership support to the community; o There are equipment and some basic material to build from; 70

o Gibeon has a poor rural population unlike many of the other highly Prosopis infested areas where there are no human settlements.

In order to address the challenges that were experienced by the Gibeon Prosopis project, the below recommendations are made, for consideration by DWA and ORASECOM.

It is recommended that the Demonstration project also investigate options to address Prosopis in other highly infested areas such as Hardap dam, Neckartal dam, Noordoewer and Nossob farm.

Institutional arrangements and organisation of harvesters

• During pilot project implementation, the community members of Gibeon organized themselves and registered a close corporation and applied for SME certification to enhance their reputation. However, the survey revealed that there was no finalized constitution that guided the operations of the corporation. Thus, it is strongly recommended that a constitution for the corporation be finalized in close consultation with the community before the official handover of the project. The constitution will contain rules and guidelines on how to operate the project e.g. election and role of project committee members, financial management e.g. requirements when withdrawing funds from project account, resolution of conflicts/disputes, and channel of communication etc.

• Finalize and facilitate signing of the contract between the community group and the Gibeon Village Council (GVC) to render support in respect of transport and storage facility as indicated initially during project implementation.

• Another aspect to consider in the Gibeon project is facilitating signing of contracts by community members involved in the project. It is recommended that the contract content be agreed upon in a consultative process with the community members.

• Another the key constraint that was reported in Gibeon is the unequal distribution of labour, which resulted in inefficient production during the project, because there were too many individuals responsible for harvesting and very few packagers. It was recommended that the community be divided into smaller groups e.g. six groups comprised of five individuals per group. In each group, three people be responsible for harvesting and two for packaging. Generally, smaller groups are seen work together better than big groups. 71

Dissemination of information and awareness raising to create a sense of ownership and solicit support

• Creation of a sense of ownership with respect to the project among the Gibeon community will be essential to ensure achievement of socio- economic project goals. The study revealed that the community members of Gibeon viewed themselves as merely workers under the project and not necessarily the owners of the project. The ideal thing would have been to involve the community members of Gibeon in all stages of planning, design and implementation of the project.

However, it is not known to what extent this was done by the project implementers, because the results indicated that there is still a requisite to exhaust other avenues to ensure that a sense of ownership is created. Hence, it was recommended that public discussions involving local participation be held with the community of Gibeon focusing on providing sufficient information pertaining the project (i.e. aims and objectives, implementation modalities and expectations etc) to ensure that all the beneficiaries are aware of the objectives and nature of the project. Such public discussions can be jointly facilitated by the DRFN, GVC and the OFBMC.

• At the time of the study, the project was still not handed over to the community, harvesting had halted and the equipment were kept by the GVC. There is a need to officially handover the project along with its equipment to revive project operations. This will also empower the Gibeon community and serve as a source of motivation.

• The need for political commitment to the project on clearing of Prosopis in Gibeon should not be underestimated. The project is envisaged to provide knowledge and skills, promote business enterprises which generate income and contribute to poverty reduction in a long-run. Therefore, it should be seen to be part of the nation’s overall process of development, implying that it should be built into any overall programme of development. In order for this to be realised and/or foster political will, there is a need for awareness campaigns and facilitation of extensive consultations and agreements with concerned government agencies e.g. Directorate of Water Affairs (DWA), Directorate of Forestry (DoF), etc. The awareness interventions should reach the decision makers and policy planners, NGOs, business community, industry partners to ensure their support and involvement in the project and create awareness of the importance of project. 72

Creation of incentives for harvesters

• Creation of incentives is essential in increasing performance and productivity of community members involved in the project. In the case of the Gibeon project, the results indicated that the community members were not motivated enough; some had put more effort into clearing of Prosopis than others. However, irrespective of these differences in effort, the payment to each individual was similar.

• Therefore, having a transparent mechanism in place that will reward community members according to their performance is imperative. It is in this vein that the study team recommends that the community members be paid based on the production output rather than time spent harvesting Prosopis firewood as it was done during pilot project implementation. In addition, payment of community members using project funds should be discouraged because it does not motivate members to work hard, adoption of a principle of “no work, no pay” is recommended. The specificities of the payment model should be worked out in consultation with the community members.

• One of the most commonly mentioned factors that contributed to some of the respondents perceiving the project as a failure is the delays in payments for the work done. It is recommended that the community members agree on a fixed day of the week/month for payments to ensure timely payments to fulfil their needs.

• Selected community members of Gibeon received once-off training on each of the following aspects: applying ecosystem approach to Natural Resources Management (NRM), safety use of equipment and clearing of Prosopis, and SME planning and financial management. Irrespective of this, the analysis revealed that the trainings offered were insufficient and this is as expected considering the fact that the community members in Gibeon has a low literacy rate, therefore they require follow up support services in terms of training.

• Specifically, limited skills in business, management and leadership were reported. It is in this vein that a recommendation is made to involve the community members in in-depth identification of relevant skills required to satisfy their needs in line with the project. Based on training needs identified by the community, training content be developed in close consultation with the community members and follow up training conducted. Overall, it is strongly recommended that training geared 73

towards enhancing managerial and entrepreneurial skills be included. Comprising of aspects such as book keeping, accounting, money saving, marketing, problem solving, and communication skills. It is anticipated that such training will empower community members of Gibeon to be creative, innovative, productive and self-reliant in their project. Thus, it is a key aspect.

• Very essential with respect to training approach, it is recommended that a multi-approach and not one training approach be adopted. Such an approach could be comprised of face-to-face or contact sessions combined with independent or self-learning. Both these approaches should be practical oriented to facilitate effective learning. Face-to-face would include workshops and project-based training (focusing on project requirements under supervision of a technical expert trainer).

• Whilst, self-learning can be facilitated through the use of self-contained modules or manuals supported by audio, do-it-yourself kits, guides, charts, leaflets and posters translated into local language. Self-learning is essential because it is cost-effective and it is known to contribute to better productivity since it promotes self-reliance and helps participants to learn easier and faster as independent learners and at their own pace.

• To enhance self-learning, community members under the project can form learning groups according to the project roles e.g. chainsaw operators, axe and knife operators, packagers, record keepers etc. This is also intended to promote the use of local resource persons within Gibeon.

• Lastly, under the training component, it is recommended to consider introducing “training of trainers” (ToT). This would entail developing the skills of selected committed community personnel already involved in the project and training them as trainers. These will serve as resource persons at local level responsible for training and capacity building of new community members who may join the project over time, since frequent recruitment and resignation of community members from project roles is inevitable.

• The use of local training institutions such as SME Compete and Institute for Management and Leadership Training (IMLT) is recommended.

Resource Mobilization

• Limited resources in terms of transport and storage facilities for harvested Prosopis firewood and project equipment is one of the key constraints threatening the viability of the Prosopis clearing project. Some recommendations to consider to address the shortcoming include:

o Carry out an inventory of facilities and equipment for the project to identify gaps and conditions of project facilities and equipment.

o Motivate and mobilise resources from relevant government and NGOs in Gibeon and at central level and confirm their commitments through signing of agreements or legal contracts as alluded to in above sections. For example, the community members of Gibeon should negotiate with GVC and request for a piece of land close to harvesting sites where a storage facility could be constructed/located e.g. mobile containers.

o Solicit funds (e.g. seed funds, loans) from potential investors such Bank Windhoek: Emerging Small and Medium Enterprises (ESME) Branch, SME Bank, and Development Fund of Namibia (DFN). However, in order for the Prosopis clearing project to attract potential investors, it is important to establish a transparent banking system that would promote investor partnerships in order to make the funding process and transactions involved more professional, reliable and efficient. finalising of their constitution will in addition add value and aid in attracting investors.

Marketing of Prosopis firewood

• During the study, it was revealed that the availability of market for Prosopis firewood was not a bottleneck per se rather the inability of the community members of Gibeon to meet the demand of a potential buyer who expressed willingness to purchase 34 tons of firewood every second week at a price of N$ 800.00 per ton produced.

• The low rate of production is due to unequal distribution of labour and regular maintenance of and insufficient equipment which results in frequent breaks, slowing down the production, as well as limited motivation of some of the harvesters. Refer to preceding sections with respect to recommendations on how to create incentives for community members and secure equipment to increase production.

• Some of the constraints linked to the market aspect is the low prices for Prosopis firewood compared to other firewood options such as Camelthorn, the unwillingness of people in trying out new products such as Prosopis wood, the lack of local market for Prosopis firewood except outside Gibeon and lack of transport to transport stock outside Gibeon. It is recommended that the community members with support from organizations raise awareness on Prosopis, with emphasis on the advantages that Prosopis firewood offer. In addition, refer to preceding sections on recommendations.

Creation of Management Information System/Database

• Creation of a simple and user-friendly Management Information System (MIS) designed for the purpose of capturing important elements of the project is highly recommended. This could be paper based or both paper and electronically based depending on local factors. The information system will be meant to capture information at two levels, namely at project level and individual (harvesters) level. The information captured in the system would include: project expenses and income, individual production output, size of area cleared among others.

• If creation of such a MIS proves expensive, an alternative would be to explore the possibilities of collaborating with GVC to capture project data into their database if they have one. Such a MIS will aid in management and decision making in terms of determining payments for individuals based on work done, minimise misunderstandings and arguments among community members over incomplete/incorrect completion of time sheets (members can track their production rates and even calculate income earned over time), and provision of information to use in negotiations with potential investors and buyers.

• It is vital that such a system is designed and developed in close consultation with community members to include their needs and they will also be a need for dedicated and fully trained personnel responsible for capturing data. Mechanisms allowing community members to regularly reconcile/validate their individual records with those in the MIS should form part of such a system to ensure transparency.

Monitoring and Evaluation of socio-economic indicators (consider combining with biophysical ones)

• Monitoring and evaluation (M&E) of project activities at every stage of implementation as well as at the end of each stage is necessary for 76

remedial correction. Regular or continuous M&E of a project will provide evidence about the immediate effectiveness of project implementation and longer-term effects. It is in this vein that the study team recommends M&E of project activities in Gibeon to allow timely adjustment of project activities. The indicators to monitor would include but not limited to the following:

o Income generation and distribution thereof o Satisfaction of community members o Organisation of community members o Degree of coordination among community/SME members o Participation level o Effectiveness of MIS o Financial management and record keeping o Utilisation and performance of equipment o Production output

• Information on these indicators could be obtained from the IMS recommended in the preceding section. Overall, feedback obtained from the M&E should be used to adjust all aspects of the project needing improvement thus ensuring cost effectiveness and a successful project.

• As usual, M&E can be time consuming and costly, therefore it is recommended that a group comprised of individuals from the OFBMC be established and tasked with the responsibility of M&E. Such a group can be comprised of experts from relevant local government departments in the basin, already existing working group of the OFBMC responsible for monitoring, and the Basin Support Officer for OFBMC among others.

CONCLUSION

The infestation by Prosopis along the Fish and Orange Rivers in southern Namibia as depicted in the results above, poses a real threat to downstream water supply as well as the natural biodiversity of the river ecosystem (Strohbach et al. in prep.). The assessment clearly shows that the abundance, density and canopy cover and health of Prosopis invader is higher in the Orange River than in the Fish River. This could be attributed to the management efforts and strategies which either government, communities or farmers are applying or it could be due to other environmental attributes associated to either climate, soil type etc.

A management programme especially in areas with high infestation, including Gibeon, Hardap dam, Neckartal, Noordowever and Nossob, to control this threat is thus essential. It is recommended that DWA and ORASECOM strengthens the efforts that were initiated at Gibeon but at the same time investigates long term sustainable solutions for the other highly infested areas. For the demonstration project, there appears to be a sustainable market for continuous harvesting of wood for firewood, which would also provide the impoverished affected communities with a valuable source of income. A number of considerations need to be taken into account:

• Institutionalization of the management of Prosopis into Government bodies and structures will ensure the sustainable management of the invader (more long-term programmes and policies be established). Currently, groundwater monitoring clearly falls in well within the mandate of DWA but monitoring of Prosopis as an alien species is not directly a DWA issue.

• Capacity development and entrepreneurship for the community members and farmers is essential for the sustainable management of this species and more related.

• Incentives for efforts and innovation such as an awarding system and ranking (greening the companies, communities, farmers etc) in order to get high recognition in other trade platforms.

The study provides a good baseline on the available woody biomass in the Orange-Fish River Basin but this should be correlated with groundwater monitoring. Institutional set up for simultaneous monitoring should be worked out so that it is institutionalised and not be merely a project driven effort.

REFERENCES

Kent, M. (2012). Vegetation Description and Analysis. A practical approach (2nd edition.). Chichester, UK: Wiley-Blackwell.

Le Maitre, D. C., Scott, D. F., & Colvin, C. (1999). Review of information on interactions between vegetation and groundwater. Water SA, 25(2), 137– 152

Liba, P., & Gretchen, C. (2009). The impact of invasive species on ecosystem services and human well-being. Stanford University. Trends in Ecology and Evolution 24(9): 497-50.

Mannheimer, C. A. (2012). Wildflowers of the Central Highlands of Namibia. Windhoek, Namibia: Macmillan Education Namibia.

Mannheimer, C. A., & Curtis, B. A. (Eds.). (2009). Le Roux and Müller’s Field Guide to the Trees and Shrubs of Namibia. Windhoek: Macmillan Education Namibia.

Müller, M. A. N. (2007). Grasses of Namibia. (J. van Eck, Ed.) (2nd ed.). Windhoek: Ministry of Agriculture, Water and Forestry.

Nilsen, E.T., Sharifi, M. R., Rundel, P. W., Jarrell, W. M., & Virginia, R.A. (1983). Diurnal and Seasonal Water Relations of the Desert Phreatophyte Prosopis Glandulosa (Honey Mesquite) in the Sonoran Desert of California. Ecological Society of America 64, 6. https://doi.org/10.2307/1937492.

Ntesa, C., Kabajani, M. & Strohbach, B.J. (2014). Baseline Assessment of Prosopis in Gibeon, Orange-Fish River Basin. Unpublished report, Desert Research Foundation of Namibia and the United States Agency for International Development (USAID), Polytechnic of Namibia, Windhoek.

QGIS (Version 2.2.0-Valmiera). (2014). Open Source Geospatial Foundation (OSGeo). Retrieved from http://qgis.org/en/site/

Stefan, A. (2005). Spread of the introduction tree Prosopis juliflora (Sw.) DC in the Lake Baringo area, Kenya. Instituionen for skoglig vegetationsekologi, Grafiska enheten, SLU, Umeå.

Strohbach, B. J. (2001). Vegetation Survey of Namibia. Journal of the Namibia Scientific Society, 49, 93–124.

Zeray, N., Legesse, B., Mohamed, J.H. & Aredo, M. (2017). Impacts of Prosopis juliflora invasion on livelihoods of pastoral and agro-pastoral households of

Dire Dawa Administration, Ethiopia. Pastoralism 7, 7. https://doi.org/10.1186/s13570-017-0079-z

ANNEXURES

Implementation Model / Conceptual Framework

Proposed Groundwater Monitoring Plan for the Orange – Fish Basin