Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non‐native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non‐native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region‐specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non‐native species richness. Non‐native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented.
1 November 2016 in African Journal of Range & Forage Science
Australian acacias have spread to many parts of the world. In South Africa, species such as A. mearnsii and dealbata are invasive. Consequently, more effort has focused on their clearing. In a cont...
4 March 2015 in International Journal of Environmental Protection and Policy
Understanding how dynamics in individual land use types influence changes in streamflow is vital. Most hydrological studies are based on paired catchment and modelling approaches. These are data intensive and require a long period of monitoring. To determine the hydrological effects of tropical vegetation conversion over large areas, it is manageable to study the same basin over different time periods. The study analysed changes in historical stream flow patterns with reference to dynamics in land cover in C52A quaternary catchment of South Africa. Landsat images for years 1993, 2004 and 2013 were used for the development of land cover maps. Subsequently, step-change (median point change, Mann-Whitney and Kruskall Willis) and trend detection tests (Spearman’s rho and Kindall’s tau) were applied to average annual discharge and rainfall data for the catchment between 1984 and 2013.Tukey’s honestly significant difference (HSD) test was also used to compare the means. Results revealed that huge land cover changes coincided with significant (p<0.05) changes in streamflow although rainfall remained homogenous over the same period. This suggests that land cover change is intricately coupled to increases in streamflow. In addition, increased runoff is usually accompanied by increased rates of erosion and siltation. To ensure sustainable management of the catchment, therefore, soil and water conservation measures are critical within the broader context of integrated water resources management.
Despite extensive research on climate change impacts and adaptation strategies in Zimbabwe, their effectiveness from the perspective of smallholder farmers, particularly in the Gwayi catchment remains insufficiently understood. This study evaluated adaptation strategies in response to land use change and climate variability using a mixed-methods approach. Data were collected through a survey of 483 smallholder farmers, 10 focus group discussions (8–12 participants), and interviews with 25 key informants. Results show that despite farmers' awareness of improved practices, adaptation remains constrained by limited access to water, quality seeds, and technology (64%), financial constraints (46%), and knowledge gaps (19%). The most common adaptation strategies include soil water conservation (85%), drought-resistant crops (80%), early planting (55%), and diversification (49%), with soil water conservation and drought-tolerant crops being the most widely practiced and perceived as most effective. Regression analysis indicates that livestock ownership, participation in community climate-resilient programs, and recent drought experiences significantly (p < 0.05) influence both the choice and number of adaptation strategies adopted. These findings highlight the need for context-specific interventions to mitigate the impacts of climate and land use changes on food security. Strengthening resilience among smallholder farmers requires improved resource access, livestock support, community-based resilience programs, capacity building, financial aid, and enhanced drought preparedness. Implementing these measures will bolster adaptive capacity and promote sustainable agricultural practices in the face of climate uncertainty.