אנו מודים חוות סקוויר Valleevue ועמק Ridge של אוניברסיטת קייס ווסטרן ריזרב, כוללים א Locci, ג בונד, וא &#39;Alldridge, לעזרה בהקמת הגינה המשותפת. י ווים, ל האפמן, ל &#39;גונזלס, SC ליהי, ב Ochocki, א Ubiles, ג יו, X. זאו, וNM צימרמן סיפקו סיוע תחום. AJB וJHB מומנו על ידי קופות הפעלה מCWRU לJHBGAD נתמכה על ידי תוכניות קיץ במענק מחקר לתואר ראשון מCWRU מומנו על ידי המכון הרפואי הווארד יוז. עבודה זו נתמכה גם על ידי מימון הקרן הלאומית למדע לJHB (DEB 1,250,170).

<ol>
	<li>Agrawal, A. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Filling+key+gaps+in+population+and+community+ecology.">Filling key gaps in population and community ecology.</a> Front. Ecol. Environ. 5, 145-152 (2007).</li><li>Suding, K. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+an+era+of+restoration+in+ecology:+successes,+failures,+and+opportunities+ahead.">Toward an era of restoration in ecology: successes, failures, and opportunities ahead.</a> Ann. Rev. Ecol. Evol. System. 42, 465-487 (2011).</li><li>Melbourne, B. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invasion+in+a+heterogeneous+world:+resistance,+coexistence+or+hostile+takeover.">Invasion in a heterogeneous world: resistance, coexistence or hostile takeover.</a> Ecol. Lett. 10, 77-94 (2007).</li><li>Lundholm, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plant+species+diversity+and+environmental+heterogeneity:+spatial+scale+and+competing+hypotheses.">Plant species diversity and environmental heterogeneity: spatial scale and competing hypotheses.</a> J. Veg. Sci. 20, 377-391 (2009).</li><li>Pacala, S. W., Tilman, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limiting+similarity+in+mechanistic+and+spatial+models+of+plant+competition+in+heterogeneous+environments.">Limiting similarity in mechanistic and spatial models of plant competition in heterogeneous environments.</a> Am. Natural. 143, 222-257 (1994).</li><li>Chesson, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=General+theory+of+competitive+coexistence+in+spatially-varying+environments.">General theory of competitive coexistence in spatially-varying environments.</a> Theor. Pop. Biol. 58, 211-237 (2000).</li><li>Bever, J. D., Westover, K. M., Antonovics, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incorporating+the+soil+community+into+plant+population+dynamics:+the+utility+of+the+feedback+approach.">Incorporating the soil community into plant population dynamics: the utility of the feedback approach.</a> J. Ecol. 85, 561-573 (1997).</li><li>Kulmatiski, A., Beard, K. H., Stevens, J. R., Cobbold, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plant-soil+feedbacks:+a+meta-analytical+review.">Plant-soil feedbacks: a meta-analytical review.</a> Ecol. Lett. 11, 980-992 (2008).</li><li>Bever, J. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rooting+theories+of+plant+community+ecology+in+microbial+interactions.">Rooting theories of plant community ecology in microbial interactions.</a> Trends. Ecol. Evol. 25, 468-478 (2010).</li><li>Brandt, A. J., de Kroon, H., Reynolds, H. L., Burns, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soil+heterogeneity+generated+by+plant-soil+feedbacks+has+implications+for+species+recruitment+and+coexistence.">Soil heterogeneity generated by plant-soil feedbacks has implications for species recruitment and coexistence.</a> J. Ecol. 101, 277-286 (2013).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> R: A language and environment for statistical computing. , (2012).</li><li>Crawley, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The R Book. , (2007).</li><li>Petermann, J. S., Fergus, A. J. F., Turnbull, L. A., Schmid, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Janzen-Connell+effects+are+widespread+and+strong+enough+to+maintain+diversity+in+grasslands.">Janzen-Connell effects are widespread and strong enough to maintain diversity in grasslands.</a> Ecology. 89, 2399-2406 (2008).</li><li>Reynolds, H. L., Haubensak, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soil+fertility,+heterogeneity,+and+microbes:+towards+an+integrated+understanding+of+grassland+structure+and+dynamics.">Soil fertility, heterogeneity, and microbes: towards an integrated understanding of grassland structure and dynamics.</a> Appl. Veg. Sci. 12, 33-44 (2009).</li><li>Sokal, R. R., Rohlf, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Biometry, 3rd edn. , (1995).</li><li>Klironomos, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Feedback+with+soil+biota+contributes+to+plant+rarity+and+invasiveness+in+communities.">Feedback with soil biota contributes to plant rarity and invasiveness in communities.</a> Nature. 417, 67-70 (2002).</li><li>Mommer, L., van Ruijven, J., Jansen, C., van de Steeg, H. M., de Kroon, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interactive+effects+of+nutrient+heterogeneity+and+competition:+implications+for+root+foraging+theory?.">Interactive effects of nutrient heterogeneity and competition: implications for root foraging theory?.</a> Funct. Ecol. 26, 66-73 (2012).</li><li>Felsenstein, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phylogenies+and+the+comparative+method.">Phylogenies and the comparative method.</a> Am. Natural. 125, 1-15 (1985).</li><li>Burns, J. H., Strauss, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=More+closely+related+species+are+more+ecologically+similar+in+an+experimental+test.">More closely related species are more ecologically similar in an experimental test.</a> Proc. Natl. Acad. Sci. U.S.A. 108, 5302-5307 (2011).</li><li>Fukami, T., Nakajima, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Community+assembly:+alternative+stable+states+or+alternative+transient+states.">Community assembly: alternative stable states or alternative transient states.</a> Ecol. Lett. 14, 973-984 (2011).</li></ol>

יש המחברים אין לחשוף.

ההטרוגניות אדמה נגרם צמח היא סבירה מאוד בקהילות טבעיות, כי יש לי צמחים השפעות גדולות, ולעתים קרובות מין ספציפיים בסביבת אדמתם ואת הצמחים הבאים שייתקלו אדמה ש( למשל Petermann et al. 13). עם זאת, ההבנה של התפקיד של סוג זה של ההטרוגניות על חברות צמחים שלנו היא מיני?...

אחת המטרות העיקריות של אקולוגיה קהילה הוא להסביר ולחזות את התהליכים המסדירים הרכבה קהילה. עם זאת, חברות צמחים הן לעתים קרובות מגוונות יותר מהצפוי על ידי התאוריה דו קיום 1, ואקולוגים שיקום צריכים להבין מנגנונים דו קיום לשחזר בהצלחה קהילות ילידים מגוונות 2. ההטרוגניות סביבתית היא מנגנון חשוב באופן תיאורטי שיכול לעזור להסביר את הרמות גבוהות של גיוון קהילה, אבל מניפולציות ניסיוני של ההטרוגניות הן נדירות 3 ויתמקדו בהטרוגניות אביוטי (למשל נסקרה ב4 Lundholm). התאוריה שמשלבת ההטרוגניות בדרך כלל מניחה כי ההטרוגניות היא חיצונית לקהילת ההרכבה. ההטרוגניות חיצונית נשלטת על ידי גורמים כגון טיפולוגיה נוף, שהם בלתי תלויים בהרכב הקהילה. ההטרוגניות חיצונית יכולה לגרום לדו קיום באמצעות מחיצות נישה (ריווינישא במלבורן et al. 3, למשל Pacala וטילמן 5 וChesson 6). עם זאת, חלק גדול מההטרוגניות הסביבתית הרלוונטית לקהילות צמח עשויה להיות מהותית לקהילה, פיתוח כקהילת מרכיב ובהתאם לזהותו של המין בקהילה. ההטרוגניות פנימית יכולה להיגרם כתוצאה מפידבקים ביוטיים, אשר יכול להוביל לחיים משותפים באמצעות תדר תלות שלילית (לדוגמא Bever et al. 7). כאן אנו מתארים שיטה חדשה לטיפול בהטרוגניות אדמה נגרם צמח, סוג של הטרוגניות אדמה שהוא מהותי לקהילה ונובע מפידבקים צמח אדמה. פידבקים צמחים קרקע (כוחות הביטחון הפלסטיניים) מתרחש כאשר צמחים משפיעים על מבנה הקרקע, כימיה, או הביוטה באופן שמשפיע על ביצועי צמח שלאחר מכן באדמה, ויש לי כוחות הביטחון הפלסטיניים השפעות ממוצעים גדולות על ביצועי מפעל בקהילות צמחים מקומיים 8. מחקרים של כוחות הביטחון הפלסטיניים יש בדרך כלל גם אספו קרקעות מהשדה או קרקעות מותנות בניסוי, ואז שאל כיצד צמחים לבצע בביחס אדמת conspecific לheterospecific או מעוקר אדמה 9. אם צמחי ביצועים טובים יותר בהשוואת אדמת conspecific הפניה קרקעות, ולאחר מכן כוחות הביטחון הפלסטיניים הם חיוביים, בעוד שאם צמחי ביצועים טובים יותר בקרקעות התייחסות, כוחות הביטחון הפלסטיניים הם שליליים. כוחות הביטחון הפלסטיניים שליליים הדדיים יכול להוביל לקיום תדירות תלויה בין המינים 7. בעוד ההשפעות הממוצעת של כוחות הביטחון הפלסטיניים הן מאופיינות היטב 8, ההשפעות של הטרוגניות המרחבית בכוחות הביטחון הפלסטיניים הם הבינו היטב 10. מכיוון שכוחות הביטחון הפלסטיניים מתרחשים בקנה המידה של צמחים בודדים 7 וכי צמחים לעתים קרובות מופצים nonrandomly במרחב ובזמן, כוחות הביטחון הפלסטיניים עשויים להוביל להטרוגניות אדמה, שאנו מכנים את ההטרוגניות אדמה נגרם צמח. שלא כמו צורות רבות אחרות של הטרוגניות (למשל טופולוגיה נוף), heterogeneit זהy הוא מהותי לקהילת ההרכבה וייתכן ובכך להשפיע על ההרכבה קהילה בצורה שונה מצורות חיצוניות יותר של הטרוגניות. על מנת להבין את ההשפעה של צורה זו של ההטרוגניות על ביצועי מפעל ודו קיום, אנחנו צריכים שיטות ניסיוניות שלתפעל ההטרוגניות אדמה נגרם צמח. הנה, אנחנו מדגימים שיטה כזו, אשר עושה שימוש בקרקעות מותנות בשני מינים כדי ליצור טיפול הטרוגנית עם טלאים נפרדים משני מקורות קרקע וטיפול הומוגנית, שהוא תערובת של שני מקורות הקרקע. ערבוב אדמה זו יכול לייצג לפחות שני תרחישים סבירים בתחום: (1) הפרעה (למשל מכרסמים, חקלאות) אשר מתערבבת קרקעות ממוצא שונה או (2) צמחים משני מינים הולך וגדל בסמיכות, כך שאזורי השפעה שלהם שורש להתערבב והומוגני. אנו מציגים שני ניסויי דוגמא המשתמשים בהטרוגניות אדמה נגרם מפעל כדי לענות על שאלות מפתח בleve שונהls של ארגון אקולוגי: (1) האם צמח אוכלוסיות להגיב לשתול-induced ההטרוגניות אדמה? ו (2) האם צמחים בודדים להגיב להטרוגניות אדמה נגרם צמח? אנו מתארים ניסוי שדה באמצעות 6 טלאי אדמה כדי לענות על השאלה הראשונה וניסוי חממה באמצעות 2 טלאי אדמה כדי לענות על השאלה השנייה. כימות שתי תגובות צמח בודדות להטרוגניות אדמת אוכלוסייה, והוא חיוני להבנת אופן הרכבה קהילת השפעות ההטרוגניות.

<table><tbody><tr><td>Shovel(s)</td><td>Any</td><td>NA</td><td>It is helpful to have at least two shovels, one for each species of soil origin.</td></tr><tr><td>Trowel(s)</td><td>Any</td><td>NA</td><td>It is necessary to have at least two trowels of identical size, one for each species of soil origin.</td></tr><tr><td>Gloves</td><td>Any</td><td>NA</td><td>Gardening gloves can be used.</td></tr><tr><td>Diluted bleach</td><td>Any</td><td>NA</td><td>We use an ~1:10 concentration of household bleach (containing 5-10% NaClO) to water to sterilize all equipment between soil collections.</td></tr><tr><td>Plastic grid(s)</td><td>Any</td><td>NA</td><td>CUSTOM. We used plastic sheeting from the construction of greenhouse walls to create the grid used in the field experiment. However any stiff plastic that can be manipulated can be used. It is helpful to have three grids to produce reciprocal heterogeneous treatments and a homogeneous treatment without needing to sterilize between each experimental unit.</td></tr><tr><td>Plastic dividers</td><td>Any</td><td>NA</td><td>CUSTOM. We used stiff sheets of plastic, cut to fit the pot minimum width, such that they can slide down to the bottom of the pot for the greenhouse experiment. It is helpful to have at least two dividers, one for heterogeneous and one for homogeneous treatments, if investigators want to randomize the order in which experimental units within a block are filled without needing to sterilize the divider in between each experimental unit.</td></tr><tr><td>Buckets or wheelbarrows</td><td>Any</td><td>NA</td><td>Any container for transporting soils.</td></tr><tr><td>Seeds</td><td>Any</td><td>NA</td><td>We collect seeds in the field by hand. Seeds can also be ordered from horticultural suppliers, if appropriate.</td></tr><tr><td>Plastic toothpicks</td><td>Soodhalter Plastics, Inc.</td><td>805KP</td><td>We plant individual seeds glued on toothpick in the field experiment to facilitate monitoring germination and survival of individuals.</td></tr><tr><td>Water soluble glue</td><td>Elmer&#039;s</td><td>Elmer&#039;s Glue-all</td><td>Any water soluble glue can be used to adhere seeds to plastic toothpicks.</td></tr><tr><td>Pots</td><td>Any</td><td>NA</td><td>Pot size will depend on experimental plants used and number of soil patches desired (&lt;em&gt;e.g.&lt;/em&gt; 2 or 6).</td></tr><tr><td>Sand</td><td>Any</td><td>NA</td><td>Coarse sand may be mixed with field soils to improve drainage in pots.</td></tr><tr><td>Lab tape&amp;nbsp;</td><td>Any</td><td>NA</td><td>Tape may be used to label equipment used in handling soils with the species of origin.</td></tr><tr><td>Pin flags</td><td>Any</td><td>NA</td><td>Flags can be used to identify individuals in the field prior to soil collection.</td></tr><tr><td>Landscape fabric</td><td>Any</td><td>NA</td><td>Landscape fabric can be used in the field to minimize the growth of plants outside experimental plots.</td></tr></tbody></table>

experimental protocol for manipulating plant-induced soil heterogeneity

תאוריה דו קיום לעתים קרובות טיפלה ההטרוגניות סביבתית כמו להיות בלתי תלוי בהרכב הקהילה, אך יש לי פידבקים ביוטיים כגון פידבקים צמחים קרקע (כוחות הביטחון הפלסטיניים) השפעה גדולה על ביצועי מפעל, וליצור הטרוגניות סביבתית שתלויות בהרכב הקהילה. הבנת החשיבות של כוחות הביטחון הפלסטיניים להרכבת קהילת צמח מחייבת הבנה של התפקיד של ההטרוגניות בכוחות הביטחון הפלסטיניים, בנוסף להשפעות מתכוונים כוחות הביטחון הפלסטיניים. כאן אנו מתארים פרוטוקול לטיפול בהטרוגניות אדמה נגרם צמח. שני ניסויי דוגמא מוצגים: (1) ניסוי שדה עם רשת 6 תיקון של קרקעות כדי למדוד את תגובות אוכלוסיית צמח ו (2) ניסוי חממה עם קרקעות 2-תיקון כדי למדוד תגובות צמח בודדות. ניתן לאסוף קרקעות מאזור השפעת השורש (קרקעות מrhizosphere וישירות סמוכות לrhizosphere) של צמחים בשדה ממינים צמחי conspecific וheterospecific. לשכפל לאסוףיונים נמצאים בשימוש כדי למנוע pseudoreplicating דגימות קרקע. לאחר מכן קרקעות אלו ממוקמות לטלאים נפרדים לטיפולים הטרוגנית או מעורבים לטיפול הומוגני. צריך להקפיד על מנת להבטיח כי טיפולים הטרוגנית והומוגני לחוות את אותה המידה של הפרעת קרקע. לאחר מכן ניתן להציב צמחים בטיפולי קרקע אלה כדי לקבוע את ההשפעה של הטרוגניות אדמה נגרם מפעל על ביצועי מפעל. אנו מראים כי תוצאות מושרה צמח הטרוגניות בתוצאות שונות מהצפוי על ידי מודלים דו קיום מסורתי, אולי בגלל האופי הדינמי של פידבקים אלה. יש צורך בתאוריה שמשלבת ההטרוגניות סביבתית השפיעה על ידי קהילת ההרכבה ועבודה אמפירית נוספת כדי לקבוע מתי ההטרוגניות פנימית לקהילת ההרכבה תביא לתוצאות תצורות שונות לעומת חיצוני ההטרוגניות בהרכב הקהילה.

מינים הגיבו ההטרוגניות אדמה לשתול המושרה בדרכים מגוונות בשתי האוכלוסייה ורמת פרט (איורים 3 ו -4), עם השלכות להרכבת קהילה. כדי לקבוע אם צמח אוכלוסיות להגיב להטרוגניות אדמה נגרם צמח, ניסוי שדה הוקם כבפרוטוקול 2 באמצעות שלושה זוגות congeneric של מינים. אוכלוס...

Watch this Scientific Journal Video about Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity at JoVE.com

פרוטוקול ניסוי למניפולציה של הטרוגניות קרקע הנגרמת על ידי צמחים | סביבה | וִידֵאוֹ

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

הבנת התפקיד של הטרוגניות סביבתית בקיום מין יש בדרך כלל מתמקד בסוגים של הטרוגניות שהם חיצוניים להרכב המינים של הקהילה. אנו מספקים שיטות מפורטות רומן ליצירת טיפולי ההטרוגניות אדמה באמצעות קרקעות כפופות לאוויר צמח אדמת משוב, או הטרוגניות מהותית בהרכב הקהילה.

פרוטוקול ניסוי להטרוגניות קרקע מושרה צמח מניפולציה

Coexistence theory has often treated environmental heterogeneity as being independent of the community composition; however biotic feedbacks such as ...

experimental-protocol-for-manipulating-plant-induced-soil

Research

Education

JoVE Journal

JoVE Core

Biology

Environment

Ecology

Population and Community Ecology

SCIENTISTS IN ACTION

18.7K Views.  Case Western Reserve University.  הבנת התפקיד של הטרוגניות סביבתית בקיום מין יש בדרך כלל מתמקד בסוגים של הטרוגניות שהם חיצוניים להרכב המינים של הקהילה. אנו מספקים שיטות מפורטות רומן ליצירת טיפולי ההטרוגניות אדמה באמצעות קרקעות כפופות לאוויר צמח אדמת משוב, או הטרוגניות מה?...

Video: Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

A Protocol for Conducting Rainfall Simulation to Study Soil Runoff

Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24&#160;hr&#160;after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff.

A rainfall simulator was used to apply a consistent rate of uniform rainfall to packed soil boxes in a study of the fate and transport of urea, a nonpoint source environmental contaminant. Under uniform soil and rainfall conditions, antecedent soil moisture content exerted strong control over urea loss in surface runoff.

פרוטוקול לעריכת סימולציה גשם לחקר ניגר קרקע

Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The ...

Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

This study presents an excavation method for investigating subsurface hydrological, geochemical, and microbiological heterogeneity of a soil lysimeter. The lysimeter simulates an artificial hillslope which was initially under homogeneous condition and had been subjected to approximately 5,000 mm of water over eight cycles of irrigation in an 18-month period.

חפירה באדמה Lysimeter עבור ההידרולוגי מצמידים, גיאוכימיות, וחקירות מיקרוביולוגיות

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled ...

Isolation and Analysis of Microbial Communities in Soil, Rhizosphere, and Roots in Perennial Grass Experiments

Plant and soil microbiome studies are becoming increasingly important for understanding the roles microorganisms play in agricultural productivity. The purpose of this manuscript is to provide detail on how to rapidly sample soil, rhizosphere, and endosphere of replicated field trials and analyze changes that may occur in the microbial communities due to sample type, treatment, and plant genotype. The experiment used to demonstrate these methods consists of replicated field plots containing two, pure, warm-season grasses (Panicum virgatum and Andropogon gerardii) and a low-diversity grass mixture (A. gerardii, Sorghastrum nutans, and Bouteloua curtipendula). Briefly, plants are excavated, a variety of roots are cut and placed in phosphate buffer, and then shaken to collect the rhizosphere. Roots are brought to the laboratory on ice and surface sterilized with bleach and ethanol (EtOH). The rhizosphere is filtered and concentrated by centrifugation. Excavated soil from around the root ball is placed into plastic bags and brought to the lab where a small amount of soil is taken for DNA extractions. DNA is extracted from roots, soil, and rhizosphere and then amplified with primers for the V4 region of the 16S rRNA gene. Amplicons are sequenced, then analyzed with open access bioinformatics tools. These methods allow researchers to test how the microbial community diversity and composition varies due to sample type, treatment, and plant genotype. Using these methods along with statistical models, the representative results demonstrate there are significant differences in microbial communities of roots, rhizosphere, and soil. Methods presented here provide a complete set of steps for how to collect field samples, isolate, extract, quantify, amplify, and sequence DNA, and analyze microbial community diversity and composition in replicated field trials.

Excavation of plant roots from the field as well as processing of samples into endosphere, rhizosphere, and soil are described in detail, including DNA extraction and data analysis methods. This paper is designed to enable other laboratories to use these techniques for the study of soil, endosphere, and rhizosphere microbiomes.

בידוד וניתוח של הקהילות מיקרוביאלית בקרקע, Rhizosphere ושורשים בניסויים עשב רב שנתי

Plant and soil microbiome studies are becoming increasingly important for understanding the roles microorganisms play in agricultural productivity. The ...

Sampling Soils in a Heterogeneous Research Plot

Soils are highly heterogeneous. In general, the number of soil samples required for soil research has always been determined arbitrarily and the associated accuracy is unknown. Here, we present a detailed protocol for efficient and clustered soil sampling in a research plot and, relying on a pilot sampling using this design, for demonstrating soil spatial heterogeneity and informing reasonable sample sizes and associated accuracy for future study. The protocol mainly comprises four steps: sampling design, field collection, soil analysis, and geostatistical analysis. The step-by-step procedure is modified according to former publications. Two examples will be presented to demonstrate contrasting spatial distributions of soil organic carbon (SOC) and soil microbial biomass carbon (MBC) under different management practices. In addition, we present a strategy to determine the sample size requirement (SSR) given a certain level of accuracy based on the plot-level coefficient of variation (CV). The field sampling protocol and the quantitative determination of the sample size will assist researchers in seeking feasible sampling strategies to meet research needs and resources' availability.

The traditional soil-sampling procedure determines the number of soil samples arbitrarily. Here, we provide a simple yet efficient clustered soil-sampling design to demonstrate soil spatial heterogeneity and quantitatively determine the number of soil samples required and the associated sampling accuracy.

קרקעות הדגימה במחקר הטרוגנית מגרש

Soils are highly heterogeneous. In general, the number of soil samples required for soil research has always been determined arbitrarily and the ...

Investigation of Plant Interactions Across Common Mycorrhizal Networks Using Rotated Cores

Arbuscular mycorrhizal (AM) fungi influence plant mineral nutrient uptake and growth, hence, they have the potential to influence plant interactions. The power of their influence is in extraradical mycelia that spread beyond nutrient depletion zones found near roots to ultimately interconnect individuals within a common mycorrhizal network (CMN). Most experiments, however, have investigated the role of AM fungi in plant interactions by growing plants with versus without mycorrhizal fungi, a method that fails to explicitly address the role of CMNs. Here, we propose a method that manipulates CMNs to investigate their role in plant interactions. Our method uses modified containers with conical bottoms with a nylon mesh and/or hydrophobic material covering slotted openings, 15N fertilizer, and a nutrient-poor interstitial sand. CMNs are left either intact between interacting individuals, severed by rotation of containers, or prevented from forming by a solid barrier. Our findings suggest that rotating containers is sufficient to disrupt CMNs and prevent their effects on plant interactions across CMNs. Our approach is advantageous because it mimics aspects of nature, such as seedlings tapping into already established CMNs and the use of a suite of AM fungi that may provide diverse benefits. Although our experiment is limited to investigating plants at the seedling stage, plant interactions across CMNs can be detected using our approach which therefore can be applied to investigate biological questions about the functioning of CMNs in ecosystems.

Most plants within communities likely are interconnected by arbuscular mycorrhizal (AM) fungi, but mediation of plant interactions by them has been investigated primarily by growing plants with versus without mycorrhizas. We present a method to manipulate common mycorrhizal networks among mycorrhizal plants to investigate their consequences for plant interactions.

החקירה של אינטראקציות צמח ברשתות Mycorrhizal נפוצות באמצעות ליבות מסובב

Arbuscular mycorrhizal (AM) fungi influence plant mineral nutrient uptake and growth, hence, they have the potential to influence plant interactions. The ...

A Telemetric, Gravimetric Platform for Real-Time Physiological Phenotyping of Plant&ndash;Environment Interactions

Food security for the growing global population is a major concern. The data provided by genomic tools far exceeds the supply of phenotypic data, creating a knowledge gap. To meet the challenge of improving crops to feed the growing global population, this gap must be bridged.
Physiological traits are considered key functional traits in the context of responsiveness or sensitivity to environmental conditions. Many recently introduced high-throughput (HTP) phenotyping techniques are based on remote sensing or imaging and are capable of directly measuring morphological traits, but measure physiological parameters mainly indirectly.
This paper describes a method for direct physiological phenotyping that has several advantages for the functional phenotyping of plant&#8211;environment interactions. It helps users overcome the many challenges encountered in the use of load-cell gravimetric systems and pot experiments. The suggested techniques will enable users to distinguish between soil weight, plant weight and soil water content, providing a method for the continuous and simultaneous measurement of dynamic soil, plant and atmosphere conditions, alongside the measurement of key physiological traits. This method allows researchers to closely mimic field stress scenarios while taking into consideration the environment&#8217;s effects on the plants&#8217; physiology. This method also minimizes pot effects, which are one of the major problems in pre-field phenotyping. It includes a feed-back fertigation system that enables a truly randomized experimental design at a field-like plant density. This system detects the soil-water-content limiting threshold (&#952;) and allows for the translation of data into knowledge through the use of a real-time analytic tool and an online statistical resource. This method for the rapid and direct measurement of the physiological responses of multiple plants to a dynamic environment has great potential for use in screening for beneficial traits associated with responses to abiotic stress, in the context of pre-field breeding and crop improvement.

A Telemetric, Gravimetric Platform for Real-Time Physiological Phenotyping of Plant&#8211;Environment Interactions

This high-throughput, telemetric, whole-plant water relations gravimetric phenotyping method enables direct and simultaneous real-time measurements, as well as the analysis of multiple yield-related physiological traits involved in dynamic plant&#8211;environment interactions.

פלטפורמה טלמטרית, כבידתית ל Phenotyping פיזיולוגי בזמן אמת של אינטראקציות צמח-סביבה

Food security for the growing global population is a major concern. The data provided by genomic tools far exceeds the supply of phenotypic data, creating ...

Inoculation Strategies to Infect Plant Roots with Soil-Borne Microorganisms

The rhizosphere harbors a highly complex microbial community in which plant roots are constantly challenged. Roots are in close contact with a wide variety of microorganisms, but studies on soil-borne interactions are still behind those performed on aboveground organs. Although some inoculation strategies for infecting model plants with model root pathogens are described in the literature, it remains difficult to get a comprehensive methodological overview. To address this problem, three different root inoculation systems are precisely described that can be applied to gain insights into the biology of root-microbe interactions. For illustration, Verticillium species (namely, V. longisporum and V. dahliae) were employed as root invading model pathogens. However, the methods can be easily adapted to other root colonizing microbes - both pathogenic and beneficial. By colonizing the plant xylem, vascular soil-borne fungi such as Verticillium spp. exhibit a unique lifestyle. After root invasion, they spread via the xylem vessels acropetally, reach the shoot, and elicit disease symptoms. Three representative plant species were chosen as model hosts: Arabidopsis thaliana, economically important oilseed rape (Brassica napus), and tomato (Solanum lycopersicum). Step-by-step protocols are given. Representative results of pathogenicity assays, transcriptional analyses of marker genes, and independent confirmations by reporter constructs are shown. Furthermore, the advantages and disadvantages of each inoculation system are thoroughly discussed. These proven protocols can assist in providing approaches for research questions on root-microbe interactions. Knowing how plants cope with microbes in the soil is crucial for developing new strategies to improve agriculture.

This protocol presents a detailed summary of strategies to inoculate plant roots with soil-borne microbes. Exemplified for the fungi Verticillium longisporum and Verticillium dahliae, three different root infection systems are described. Potential applications and possible downstream analyses are highlighted, and advantages or disadvantages are discussed for each system.

אסטרטגיות חיסון להדבקת שורשי צמחים במיקרואורגניזמים הנישאים בקרקע

The rhizosphere harbors a highly complex microbial community in which plant roots are constantly challenged. Roots are in close contact with a wide ...

Simulating Temperature in a Soil Incubation Experiment

The study of warming impact on soils requires a realistic and accurate representation of temperature. In laboratory incubation studies, a widely adopted method has been to render constant temperatures in multiple chambers, and via comparisons of soil responses between low- and high-temperature chambers, to derive the warming impact on soil changes. However, this commonly used method failed to imitate both the magnitude and amplitude of actual temperatures as observed in field conditions, thus potentially undermining the validity of such studies. With sophisticated environmental chambers becoming increasingly available, it is imperative to examine alternative methods of temperature control for soil incubation research. This protocol will introduce a state-of-the-art environmental chamber and demonstrate both conventional and new methods of temperature control to improve the experimental design of soil incubation. The protocol mainly comprises four steps: temperature monitoring and programming, soil collection, laboratory incubation, and warming effect comparison. One example will be presented to demonstrate different methods of temperature control and the resultant contrasting warming scenarios; that is, a constant temperature design referred to as stepwise warming (SW) and simulated in situ temperature design as gradual warming (GW), as well as their effects on soil respiration, microbial biomass, and extracellular enzyme activities. In addition, we present a strategy to diversify temperature change scenarios to meet specific climate change research needs (e.g., extreme heat). The temperature control protocol and the recommended well-tailored and diversified temperature change scenarios will assist researchers in establishing reliable and realistic soil incubation experiments in the laboratory.

Laboratory soil warming experiments usually employ two or more constant temperatures in multiple chambers. By presenting a sophisticated environmental chamber, we provide an accurate temperature control method to imitate the magnitude and amplitude of in situ soil temperature and improve the experimental design of soil incubation studies.

הדמיית טמפרטורה בניסוי דגירה בקרקע

The study of warming impact on soils requires a realistic and accurate representation of temperature. In laboratory incubation studies, a widely adopted ...

JenaTron - An Experimental Approach to Study the Effects of Plant History and Soil History on Grassland Ecosystem Functioning

The global loss of biodiversity has motivated many studies that experimentally vary plant species richness and examine the consequences for ecosystem functioning. Such experiments generally show a positive relationship between above- and below-ground biodiversity and the functioning of terrestrial ecosystems. Moreover, this relationship tends to strengthen over time, seen as enhanced functioning of diverse plant communities and reduced functioning of low-diversity plant communities. Differences in multitrophic community assembly and biotic interactions in high- versus low-diversity plant communities are hypothesized to affect plant performance by altering consumer community structure and function and driving plastic or micro-evolutionary responses of plant species in the plant communities. To resolve this complex interplay of community history, we separated these effects into plant and soil history. Plant history refers to all plant-level responses to past abiotic and biotic selection pressures experienced in their communities, while soil history relates to all abiotic and biotic soil properties developed as a legacy of plant-soil interactions under variable plant diversity. We set up a biodiversity experiment in an Ecotron, a terrestrial mesocosm facility that allows controlling environmental conditions above- and below-ground, to test whether the strengthening biodiversity-ecosystem functioning relationship is due to soil history, plant history, or a combination of both. We established a plant diversity gradient consisting of 1, 2, 3, and 6 grassland plant species and factorially nested with soil history and plant history treatments for each level of plant species richness. Representative results demonstrate the successful establishment of target treatments in the Ecotron experiment, observing the effects of plant and soil history on initial plant development and final plant growth. Additionally, we provide a case study for data analysis of individual response variables. We outline research objectives and methods to comprehensively assess the multifunctional responses to the experimental treatments necessary to ultimately address the overarching hypothesis.

Here we present a study established in the iDiv Ecotron, terrestrial mesocosm chambers with controlled environmental conditions above- and below-ground, to study the independent and interactive effects of plant history and soil history on ecosystem functioning of grassland communities along a plant diversity gradient.

JenaTron - גישה ניסויית לחקר ההשפעות של היסטוריית הצמח וההיסטוריה של הקרקע על תפקוד המערכת האקולוגית של העשב

The global loss of biodiversity has motivated many studies that experimentally vary plant species richness and examine the consequences for ecosystem ...

שיפור קיבועCO2 : גישת ביוטה של הקרקע להגברת בליה מינרלית

Design and Construction of an Experimental Setup to Enhance Mineral Weathering through the Activity of Soil Organisms

Enhanced weathering (EW) is an emerging carbon dioxide (CO2) removal technology that can contribute to climate change mitigation. This technology relies on accelerating the natural process of mineral weathering in soils by manipulating the abiotic variables that govern this process, in particular mineral grain size and exposure to acids dissolved in water. EW mainly aims at reducing atmospheric CO2 concentrations by enhancing inorganic carbon sequestration. Until now, knowledge of EW has been mainly gained through experiments that focused on the abiotic variables known for stimulating mineral weathering, thereby neglecting the potential influence of biotic components. While bacteria, fungi, and earthworms are known to increase mineral weathering rates, the use of soil organisms in the context of EW remains underexplored. 
 This protocol describes the design and construction of an experimental setup developed to enhance mineral weathering rates through soil organisms while concurrently controlling abiotic conditions. The setup is designed to maximize weathering rates while maintaining soil organisms' activity. It consists of a large number of columns filled with rock powder and organic material, located in a climate chamber and with water applied via a downflow irrigation system. Columns are placed above a fridge containing jerrycans to collect the leachate. Representative results demonstrate that this setup is suitable to ensure the activity of soil organisms and quantify their effect on inorganic carbon sequestration. Challenges remain in minimizing leachate losses, ensuring homogeneous ventilation through the climate chamber, and avoiding flooding of the columns. With this setup, an innovative and promising approach is proposed to enhance mineral weathering rates through the activity of soil biota and disentangle the effect of biotic and abiotic factors as drivers of EW.

מחבר זרקור: חשיפת תפקידן של תולעי אדמה בשיפור בליה מינרלית לסילוק CO2 

Here we present the construction and operation of an experimental setup to enhance mineral weathering through the activity of soil organisms while concurrently manipulating abiotic variables known to stimulate weathering. Representative results from the functioning of the setup and sample analyses are discussed together with points for improvement.

תכנון ובנייה של מערך ניסיוני לשיפור בליה מינרלית באמצעות פעילות אורגניזמים בקרקע

Enhanced weathering (EW) is an emerging carbon dioxide (CO2) removal technology that can contribute to climate change mitigation. This technology relies ...