{"id":3029,"date":"2015-06-23T14:47:49","date_gmt":"2015-06-23T12:47:49","guid":{"rendered":"http:\/\/blogs.sun.ac.za\/cib\/?p=3029"},"modified":"2020-08-28T15:09:31","modified_gmt":"2020-08-28T13:09:31","slug":"thirsty-invaders-leave-rivers-with-less-water","status":"publish","type":"post","link":"https:\/\/blogs.sun.ac.za\/cib\/thirsty-invaders-leave-rivers-with-less-water\/","title":{"rendered":"Thirsty invaders leave rivers with less water"},"content":{"rendered":"<p>Invasive alien plants can change the amount of rainwater that reaches rivers and streams. Some researchers found that there is a large impact, with substantial increases in water uptake and reduced volumes of water in rivers, while others found little or no impact. The level of impact can be explained by the differences in the structure (e.g. height, depth of the roots) and the physiology (e.g. evergreen versus deciduous) between alien and indigenous plants.<\/p>\n<p>In a recent study, C\u00b7I\u00b7B Associate David Le Maitre (<a href=\"http:\/\/www.csir.co.za\/nre\/index.html\" target=\"_blank\" rel=\"noopener noreferrer\">Council for Scientific and Industrial Research<\/a>) and colleagues reviewed the impacts of South Africa\u2019s major invaders on surface runoff and groundwater resources.<\/p>\n<p>They found that when two species have similar characteristics, the differences are minor but where there are marked contrasts &#8211; for example seasonal indigenous grassland versus evergreen alien trees, or shallow rooted versus deep rooted species \u2013 the differences in water uptake can be substantial. He explains \u201c<em>Where evergreen Black wattle (<\/em>Acacia mearnsii<em>) invades seasonal riverine grasslands in summer rainfall areas, the difference can reach up to 4\u00a0840m<sup>3<\/sup>\/ha\/year for dense invasions. If we put that in perspective \u2013 it is enough water to keep 10 families of four people supplied with 200 litres for each person per day for about 1.5 years.<\/em>\u201d<\/p>\n<p>However, changes in water flows are not limited to invasive alien plants. Similar differences have been found when there are changes in the structure of indigenous plant communities, such as increases in the densities of woody plants (known as bush encroachment).<\/p>\n<blockquote><p>\u201c<em>Changes in water flow are critical for a water scarce country like South Africa where many invading plants use far more water than the indigenous species they replace<\/em>.\u201d says Le Maitre, lead author of the paper published in <em>AoB PLANTS<\/em>.<\/p><\/blockquote>\n<h4><u>Read the paper<\/u><\/h4>\n<p><a href=\"http:\/\/aobpla.oxfordjournals.org\/content\/early\/2015\/04\/29\/aobpla.plv043.full.pdf+html\" target=\"_blank\" rel=\"noopener noreferrer\">D.C. Le Maitre, M.B Gush and S. Dzikiti. 2015. Impacts of invading alien plant species on water flows at stand and catchment scales. <em>AoB PLANTS<\/em>.<\/a><\/p>\n<p>For more information, contact David Le Maitre at <a href=\"mailto:dlmaitre@csir.co.za\">dlmaitre@csir.co.za<\/a><\/p>\n<figure id=\"attachment_3030\" aria-describedby=\"caption-attachment-3030\" style=\"width: 774px\" class=\"wp-caption aligncenter\"><img fetchpriority=\"high\" decoding=\"async\" class=\"size-full wp-image-3030\" src=\"http:\/\/blogs.sun.ac.za\/cib\/files\/2020\/08\/MainImage.fw_.png\" alt=\"Black wattle, Acacia mearnsii\" width=\"774\" height=\"579\" srcset=\"https:\/\/blogs.sun.ac.za\/cib\/files\/2020\/08\/MainImage.fw_.png 774w, https:\/\/blogs.sun.ac.za\/cib\/files\/2020\/08\/MainImage.fw_-580x434.png 580w, https:\/\/blogs.sun.ac.za\/cib\/files\/2020\/08\/MainImage.fw_-768x575.png 768w, https:\/\/blogs.sun.ac.za\/cib\/files\/2020\/08\/MainImage.fw_-400x300.png 400w\" sizes=\"(max-width: 774px) 100vw, 774px\" \/><figcaption id=\"caption-attachment-3030\" class=\"wp-caption-text\">Black wattle, Acacia mearnsii (Photo credit: Suzaan Kritzinger-Klopper)<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Invasive alien plants can change the amount of rainwater that reaches rivers and streams. Some researchers found that there is a large impact, with substantial increases in water uptake and reduced volumes of water in rivers, while others found little or no impact.<\/p>\n","protected":false},"author":237,"featured_media":3030,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"ocean_post_layout":"","ocean_both_sidebars_style":"","ocean_both_sidebars_content_width":0,"ocean_both_sidebars_sidebars_width":0,"ocean_sidebar":"","ocean_second_sidebar":"","ocean_disable_margins":"enable","ocean_add_body_class":"","ocean_shortcode_before_top_bar":"","ocean_shortcode_after_top_bar":"","ocean_shortcode_before_header":"","ocean_shortcode_after_header":"","ocean_has_shortcode":"","ocean_shortcode_after_title":"","ocean_shortcode_before_footer_widgets":"","ocean_shortcode_after_footer_widgets":"","ocean_shortcode_before_footer_bottom":"","ocean_shortcode_after_footer_bottom":"","ocean_display_top_bar":"default","ocean_display_header":"default","ocean_header_style":"","ocean_center_header_left_menu":"","ocean_custom_header_template":"","ocean_custom_logo":0,"ocean_custom_retina_logo":0,"ocean_custom_logo_max_width":0,"ocean_custom_logo_tablet_max_width":0,"ocean_custom_logo_mobile_max_width":0,"ocean_custom_logo_max_height":0,"ocean_custom_logo_tablet_max_height":0,"ocean_custom_logo_mobile_max_height":0,"ocean_header_custom_menu":"","ocean_menu_typo_font_family":"","ocean_menu_typo_font_subset":"","ocean_menu_typo_font_size":0,"ocean_menu_typo_font_size_tablet":0,"ocean_menu_typo_font_size_mobile":0,"ocean_menu_typo_font_size_unit":"px","ocean_menu_typo_font_weight":"","ocean_menu_typo_font_weight_tablet":"","ocean_menu_typo_font_weight_mobile":"","ocean_menu_typo_transform":"","ocean_menu_typo_transform_tablet":"","ocean_menu_typo_transform_mobile":"","ocean_menu_typo_line_height":0,"ocean_menu_typo_line_height_tablet":0,"ocean_menu_typo_line_height_mobile":0,"ocean_menu_typo_line_height_unit":"","ocean_menu_typo_spacing":0,"ocean_menu_typo_spacing_tablet":0,"ocean_menu_typo_spacing_mobile":0,"ocean_menu_typo_spacing_unit":"","ocean_menu_link_color":"","ocean_menu_link_color_hover":"","ocean_menu_link_color_active":"","ocean_menu_link_background":"","ocean_menu_link_hover_background":"","ocean_menu_link_active_background":"","ocean_menu_social_links_bg":"","ocean_menu_social_hover_links_bg":"","ocean_menu_social_links_color":"","ocean_menu_social_hover_links_color":"","ocean_disable_title":"default","ocean_disable_heading":"default","ocean_post_title":"","ocean_post_subheading":"","ocean_post_title_style":"","ocean_post_title_background_color":"","ocean_post_title_background":0,"ocean_post_title_bg_image_position":"","ocean_post_title_bg_image_attachment":"","ocean_post_title_bg_image_repeat":"","ocean_post_title_bg_image_size":"","ocean_post_title_height":0,"ocean_post_title_bg_overlay":0.5,"ocean_post_title_bg_overlay_color":"","ocean_disable_breadcrumbs":"default","ocean_breadcrumbs_color":"","ocean_breadcrumbs_separator_color":"","ocean_breadcrumbs_links_color":"","ocean_breadcrumbs_links_hover_color":"","ocean_display_footer_widgets":"default","ocean_display_footer_bottom":"default","ocean_custom_footer_template":"","ocean_post_oembed":"","ocean_post_self_hosted_media":"","ocean_post_video_embed":"","ocean_link_format":"","ocean_link_format_target":"self","ocean_quote_format":"","ocean_quote_format_link":"post","ocean_gallery_link_images":"on","ocean_gallery_id":[],"footnotes":""},"categories":[73242,3256],"tags":[73324,64257,127,71753,3237,73327],"class_list":["post-3029","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-2015-news","category-news","tag-hydrological-impacts","tag-invasive-alien-plants","tag-resources","tag-vegetation-structure","tag-water","tag-water-use","entry","has-media"],"acf":[],"_links":{"self":[{"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/posts\/3029","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/users\/237"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/comments?post=3029"}],"version-history":[{"count":1,"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/posts\/3029\/revisions"}],"predecessor-version":[{"id":3031,"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/posts\/3029\/revisions\/3031"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/media\/3030"}],"wp:attachment":[{"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/media?parent=3029"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/categories?post=3029"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.sun.ac.za\/cib\/wp-json\/wp\/v2\/tags?post=3029"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}