Distribution of parthenium weed (Parthenium hysterophorus) in Nakuru County, Kenya

Abstract

This study sought to map the distribution of parthenium weed in Nakuru County. Field surveys were conducted in September 2021 using the quadrat method, whereby the road stretch between Naivasha junction and Kibunja was used as the main transect. Data on the presence or absence of parthenium weed was recorded, and the geographical coordinates were taken using a hand-held GPS receiver and loaded into ArcGIS 9.3 computer software for the development of a parthenium-distribution map. Data were analysed using IBM SPSS V. 28 statistical tool (SPSS Inc., Chicago, IL). Correlation analysis (at a 5% significance level) was used to show the relationship between the presence of parthenium weed and elevation, while descriptive analyses were used to determine the proportion of invaded quadrats. The results of this study revealed that parthenium weed was widespread in Nakuru County, with 79.2% of quadrats sampled invaded. The majority of parthenium weed invasions were reported in low-altitude regions (<1999 M ASL), especially those between Naivasha and Nakuru (r = -0.507, P < 0.001). This study showed that Nakuru County is threatened by parthenium weed due to its vast distribution. Therefore, the County Government of Nakuru should prioritise parthenium weed management to avert further spread. This study sought to map the distribution of parthenium weed in Nakuru County. Field surveys were conducted in September 2021 using the quadrat method, whereby the road stretch between Naivasha junction and Kibunja was used as the main transect. Data on the presence or absence of parthenium weed was recorded, and the geographical coordinates were taken using a hand-held GPS receiver and loaded into ArcGIS 9.3 computer software for the development of a parthenium-distribution map. Data were analysed using IBM SPSS V. 28 statistical tool (SPSS Inc., Chicago, IL). Correlation analysis (at a 5% significance level) was used to show the relationship between the presence of parthenium weed and elevation, while descriptive analyses were used to determine the proportion of invaded quadrats. The results of this study revealed that parthenium weed was widespread in Nakuru County, with 79.2% of quadrats sampled invaded. The majority of parthenium weed invasions were reported in low-altitude regions (<1999 M ASL), especially those between Naivasha and Nakuru (r = -0.507, P < 0.001). This study showed that Nakuru County is threatened by parthenium weed due to its vast distribution. Therefore, the County Government of Nakuru should prioritise parthenium weed management to avert further spread.

Contextualizing Parthenium abundance with hydro-edaphic conditions and native plant species in different land systems in Baringo, Kenya

“…Thus, our results suggest that the invasive Parthenium significantly affects the native vegetation in the various land system types of the Njemps Flats of Kenya, as reported before from other sites in Kenya (Odour, 2022) from drylands in Ethiopia(Ayele et al, 2010) and from rangeland ecosystems in South Africa(Tiawoun et al, 2024). The associated decline in species diversity and evenness with an increasing Parthenium infestation (Figures2 and 3) indicates not only a change in floral composition but also a homogenization of the native vegetation communities as previously reported from studies in Nepal(Timsina et al, 2011) and from other areas in Kenya(Mutua et al, 2022,). Such change trends in the presence of Parthenium are likely to be related to the high competitive ability of Parthenium in establishment and for resource use.…”

Ecological Traits and Socio-Economic Impacts of the Alien Invader Weed Parthenium hysterophorus L. in South Africa’s Rangeland Ecosystems: A Review

“…Reproduction ability is one of the most crucial biological traits for the effectiveness of Parthenium as a weed [45]. The viability of the seeds and their dispersal are also major concerns for the successful invasion of this weed.…”