{"id":144334,"date":"2013-10-03T13:31:31","date_gmt":"2013-10-03T12:31:31","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/universo\/?p=144334"},"modified":"2013-10-03T13:31:31","modified_gmt":"2013-10-03T12:31:31","slug":"relacion-entre-la-profundidad-del-suelo-y-la-biodiversidad-vegetal","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2013\/10\/03\/144334","title":{"rendered":"Relaci\u00f3n entre la profundidad del suelo y la biodiversidad vegetal"},"content":{"rendered":"

El tema que abordaremos hoy se me antoja sumamente interesante con vistas a mostrar las relaciones entre el medio ed\u00e1fico y la diversidad vegetal<\/strong><\/span>, o como m\u00ednimo de las plantas vasculares. La informaci\u00f3n la encontramos en el blog \u00a0The EEB & flow<\/a>, si bien a posteriori detectamos que el art\u00edculo original estaba en acceso abierto, cuyo enlace para acceder a su contenido incluimos\u00a0m\u00e1s abajo. Los autores \u00a0afirman haber detectado que en los ecosistemas de praderas existe relaci\u00f3n clara y positiva entre biodiversidad de las plantas vasculares y la profundidad del suelo<\/strong>.<\/span> Dicho de otro modo, tan solo la variable mentada (espesor del<\/strong><\/span> solum<\/a>) da cuenta de un aumento de la diversidad vegetal a\u00e9rea<\/strong><\/span>. En consecuencia, cabr\u00eda inferir que conforme un suelo evoluciona y se hace m\u00e1s profundo, se genera \u201cde alg\u00fan modo\u201d un medio para el incremento de la riqueza de las plantas que pueden crecer sobre \u00e9l. Eso s\u00ed, dando la vuelta al razonamiento, la erosi\u00f3n del suelo deber\u00eda disminuir la diversidad de las plantas que<\/span><\/strong> pueden acaecer en el\u00a0lugar afectado. Mutatis mutandis<\/em>, dado que el recurso ed\u00e1fico no puede considerarse renovable a escala humana, una vez erosionado, y en ausencia de m\u00e1s perturbaciones, las comunidades vegetales que crezcan sobre el ser\u00e1n menos biodiversas durante muchos a\u00f1os, por no decir siglos. Ya hablaremos en otro post de este asunto.<\/p>\n

M\u00e1s aun, los investigadores que llevaron a cabo el estudio dicen constatar que el patr\u00f3n obedece a la denominada teor\u00eda<\/strong> <\/span>(mejor calificarla de hip\u00f3tesis) de los conjuntos anidados<\/strong><\/span>, de la que ya os hemos hablado en el siguiente post: \u00a0Biodiversidad, Edafodiversidad y Teor\u00eda de los Subconjuntos Anidados<\/a> y sobre la que viene trabajando el impresentable autor de esta bit\u00e1cora desde hace a\u00f1os. Los perfiles ed\u00e1ficos m\u00e1s someros son los m\u00e1s pobres en especies, aumentando su n\u00famero conforme aumenta la profundidad del solum, pero sin perder las especies que aparecen en los primeros<\/strong><\/span>. De este modo se a\u00f1aden m\u00e1s y m\u00e1s especies de una forma en absoluto aleatoria<\/strong><\/span>, sino predecible hasta cierto punto, por cuanto los solum con mayor espesor atesoran las especies<\/strong><\/span> de los delgados y otras idiosincr\u00e1sicas<\/strong><\/span> en exclusiva. Tal repercusi\u00f3n del medio ed\u00e1fico sobre la diversidad vegetal no tiene en cuenta el proceso de horizonaci\u00f3n natural<\/a> que ocurre en la mayor parte de los tipos de suelos o edafotaxa, la cual tambi\u00e9n repercute positivamente sobre la biodiversidad<\/span><\/strong> que acaece sobre su superficie y bajo ella (biota ed\u00e1fica), como os comentamos, por ejemplo, en el siguiente post<\/a>, entre otros.<\/p>\n

La figura que os mostramos es francamente ilustrativa. De ella se desprende que\u2026<\/p>\n

\"biodiversidad-y-profundidad-del-suelo\"<\/p>\n

Diversidad vegetal, profundidad del suelo y fraccionamiento de los nichos ecol\u00f3gicos radiculares. Fuente: The EEB & flow<\/a>,<\/p>\n

\u2026la profundidad de enraizamiento var\u00eda con las especies<\/strong><\/span>. Unas enra\u00edzan someramente mientras que otras lo hacen (opcionalmente o por necesidad) m\u00e1s abajo. De esta manera se reparten los recursos mediante un proceso que equivaldr\u00eda o se asemeja a los que los ec\u00f3logos denominan partici\u00f3n o fragmentaci\u00f3n de nichos<\/strong><\/span>.<\/p>\n

Resulta interesante observar como estos investigadores llevaron a cabo el experimento sobre el mismo tipo de suelo o edafotaxa, manipul\u00e1ndolos con vistas a<\/strong><\/span> impedir el desarrollo radicular a distintas profundidades. \u00bfCu\u00e1les son las posibles razones de este patr\u00f3n?.<\/strong><\/span><\/p>\n

Al incrementarse la profundidad del suelo aumenta tambi\u00e9n el \u00e1rea intersticial que pueden explorar las plantas y sus micorrizas, pero al mismo tiempo almacenan m\u00e1s agua y durante m\u00e1s tiempo. Los suelos se secan de arriba abajo, por lo que los m\u00e1s profundos retendr\u00e1n m\u00e1s agua y a lo largo de periodos m\u00e1s prolongados en sus partes cercanas a la roca madre. De este modo se puede abastecer a especies con distinta fenolog\u00eda y requerimientos h\u00eddricos en mayor medida que en los suelos someros<\/strong><\/span>. Ciertamente la experiencia de campo se nos antoja sencilla y heur\u00edstica. Poco se hab\u00eda hablado del fraccionamiento o partici\u00f3n de nichos ecol\u00f3gicos radiculares de forma que<\/strong> <\/span>puede relacionarse con la edafog\u00e9nesis de suelos.<\/p>\n

Juan Jos\u00e9 Ib\u00e1\u00f1ez<\/strong><\/span><\/p>\n

http:\/\/evol-eco.blogspot.com.es\/2009_11_01_archive.html<\/a><\/p>\n

Wednesday, November 25, 2009<\/strong><\/p>\n

Taking below-ground processes seriously: plant coexistence and soil depth<\/a><\/strong><\/strong><\/p>\n

Some of the earliest ecologists, like Eugen Warming<\/a> and Christen Raunkiaer<\/a>, were enthralled with the minutia of the differences in plant life forms and how these differences determined where plants lived. They realized that differences in plant growth forms corresponded to how different plants made their way in the world. Since this early era, understanding the mechanisms of plant competition is one of the most widely-studied aspects of ecology<\/strong>. This is such an important aspect of ecology because understanding plant coexistence allows us to understand what controls productivity in the basal trophic level for most terrestrial food webs. There are a plethora of plausible mechanisms for how plants are able to coexist, and<\/strong> most involve above-ground partitioning strategies<\/strong> (such as different leaf shapes) or phenological differences<\/strong> (such as germination or bolting timing). Yet, below-ground interactions among plants as a way to understand competition and coexistence have been making a strong resurgence in the literature lately<\/strong>. This resurgence has been driven by new hypotheses<\/strong> and technologies. In what is probably the best hypothesis test of the role for below-ground niche partitioning<\/strong>, Mathew Dornbush<\/a> and Brian Wilsey<\/a> reveal how soil depth can affect coexistence<\/strong>. They seeded 36 tallgrass prairie species into plot tha<\/strong>t were either shallow, medium or deep soiled, and asked if species richness and diversity were affected after 3 years. They found that species richness significantly increased with increased soil depth, revealing that deeper soils likely had greater niche opportunities for species<\/strong>. Not only did deeper soils harbor greater richness, but compositions were non-random subsets<\/strong>. The species inhabiting shallow soils were a subset of medium soils, and medium a subset of deep<\/strong>. This means that increasing depth opened new niche opportunities, unique from the ones for shallow soils<\/strong>.<\/p>\n

This study is the first field-based experiment of soil depth and coexistence, that I know of and the results are compelling. Plant species are segregating below-ground niches, and perhaps we look for other partitioning strategies for species that inhabit the same soil depth.<\/p>\n

Dornbush, M., & Wilsey, B. (2009). Experimental manipulation of soil depth alters species richness and co-occurrence in restored tallgrass prairie<\/a> Journal of Ecology<\/em> DOI: 10.1111\/j.1365-2745.2009.01605.x<\/a><\/p>\n

Resumen del trabajo original que se encuentra en acceso abierto<\/strong><\/span>.<\/p>\n

Experimental manipulation of soil depth alters species richness and co-occurrence in restored tallgrass prairie<\/strong><\/span><\/p>\n

Mathew E. Dornbush1* and Brian J. Wilsey2<\/p>\n

1Department of Natural and Applied Sciences, 2420 Nicolet Drive, University of Wisconsin-Green Bay, Green Bay,<\/p>\n

WI 54311, USA; and 2Department of Ecology, Evolution and Organismal Biology, 253 Bessey Hall, Iowa State<\/p>\n

University, Ames, IA 50011, USA<\/p>\n

Summary<\/strong><\/span><\/p>\n

1. In relatively fertile ecosystems, such as the tallgrass prairie, local species diversity is largely controlled by the competitive effects of community dominants. Despite the relative importance of soil resources in shaping competitive outcomes, we have a limited understanding of the ways by which plants partition below-ground space and resources while competing, and thus, how these interactions feedback to affect local diversity.<\/p>\n

2. We experimentally tested whether potential rooting depth affected plant species diversity and composition by seeding 36 tallgrass prairie species into replicated, bare-ground plots in which soil depth was manipulated to produce shallow- (20 cm), medium- (42 cm) and deep-soil treatments all within one soil type<\/strong>. Because root architecture and foraging strategies differ among species, we hypothesized that soil depth alone could affect plant richness, diversity and community composition.<\/p>\n

3. After 3 years, richness (S) significantly increased with soil depth (P < 0.0001), but there was no significant change in species diversity (P > 0.1) or composition (multi-response permutation procedure, P > 0.2). The lack of a depth effect upon diversity resulted from the opposing effect of increasing soil depth enhancing S, but decreasing evenness.<\/p>\n

4. Species presence among depth treatments was strongly nested, with species found in shallow soils reflecting a subset of the species found in the medium-depth treatment, and the species found within the medium-depth treatment reflecting a subset of those found in the deepest soils.<\/p>\n

5. All depth treatments contained the same dominant grasses, thus differences in S resulted from the nested loss of forbs. Conversely, increasing soil depth added sets of new species, but the specific identity of the species present appeared interchangeable among replicates of a given depth.<\/p>\n

6. Synthesis. Our results provide the first field-based experimental evidence that altering soil depth alters species occurrence and diversity in predictable ways in seeded tallgrass prairie.<\/p>\n

Our results have important theoretical implications for understanding the processes promoting plant co-occurrence in grasslands, and generate testable hypotheses concerning the conditions under which root-niche partitioning<\/strong> is probably important for maintaining local richness in grasslands.<\/p>\n

Future work is needed to elucidate the generality and mechanistic basis of our results.<\/p>\n

Key-words: below-ground processes, community assembly, niche partitioning, plant diversity, roots, soil depth, tallgrass prairie<\/p>\n

Other notable recent papers on below-ground processes<\/span>:<\/strong><\/p>\n

Bartelheimer, M., Gowing, D., & Silvertown, J. (2009). Explaining hydrological niches: the decisive role of below-ground competition in two closely related species Journal of Ecology<\/em> DOI: 10.1111\/j.1365-2745.2009.01598.x<\/a><\/p>\n

Cramer, M., van Cauter, A., & Bond, W. (2009). Growth of N-fixing African savanna species is constrained by below-ground competition with grass Journal of Ecology<\/em> DOI: 10.1111\/j.1365-2745.2009.01594.x<\/a><\/p>\n

Meier, C., Keyserling, K., & Bowman, W. (2009). Fine root inputs to soil reduce growth of a neighbouring plant via distinct mechanisms dependent on root carbon chemistry Journal of Ecology, 97<\/em> (5), 941-949 DOI: 10.1111\/j.1365-2745.2009.01537.x<\/a><\/p>\n

Posted by Marc Cadotte at 5:51 PM<\/a> 1 comments<\/a> \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <\/a><\/p>\n

Labels: below-ground<\/a>, community ecology<\/a>, competition<\/a>, plants<\/a>, Research releases<\/a>, roots<\/a><\/p>\n

\u00a0A total of 75 plots with 7,200 plants were used. We found that 1) NPP increased dramatically with increased species richness (Tilman et al. 2001, Hector et al. 2001), 2) that relationships between NPP and S were consistent between the species evenness treatments, 3) local extinctions, which began to occur during the<\/p>\n

latter half of the experiment, were higher in plots planted with low evenness and in species with low aboveground growth rates, and 4) native grass species tend to have higher root growth, especially at deeper soil depths than introduced grass species (Wilsey and Polley 2004, and Wilsey and Polley in review). \u2026..<\/p>\n

\u00a0Sobre la profundidad del suelo y sus relaciones con la diversidad ver tambi\u00e9n en acceso abierto en el siguiente art\u00edculo.<\/p>\n

\u00a0SOIL RESOURCES REGULATE PRODUCTIVITY AND DIVERSITY IN<\/a>\u00a0NEWLY ESTABLISHED TALLGRASS PRAIRIE<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

El tema que abordaremos hoy se me antoja sumamente interesante con vistas a mostrar las relaciones entre el medio ed\u00e1fico y la diversidad vegetal, o como m\u00ednimo de las plantas vasculares. La informaci\u00f3n la encontramos en el blog \u00a0The EEB & flow, si bien a posteriori detectamos que el art\u00edculo original estaba en acceso abierto, cuyo enlace para acceder a su contenido incluimos\u00a0m\u00e1s abajo. Los autores \u00a0afirman haber detectado que en los ecosistemas de praderas existe relaci\u00f3n clara y positiva entre biodiversidad de las plantas vasculares y la profundidad del suelo. Dicho de otro modo, tan solo la variable mentada\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[596,590,586,588,589,600,585],"tags":[46908,24599,46752],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/144334"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=144334"}],"version-history":[{"count":9,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/144334\/revisions"}],"predecessor-version":[{"id":144556,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/144334\/revisions\/144556"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=144334"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=144334"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=144334"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}