The Ecological Role Of Biological Soil Crusts In The Rome Sand Plains of Central NY
The Ecological Role of Biological Soil Crusts in the Rome Sand Plains Carlos Rymer Advisor: Rebecca Schneider Cornell Biological Field Station Cornell University
What are Biological Soil Crusts? <ul><li>Their ecological roles include: </li></ul><ul><li>Soil stabilization </li></ul><ul><li>Organic matter fixture </li></ul><ul><li>Water availability improvement </li></ul><ul><li>Moisture contribution </li></ul><ul><li>Heat absorption </li></ul>Cyanobacteria and Moss Lichen Lycopod This biological soil crust is found in the Central Range of the Dominican Republic.
BSC’s are Everywhere Colorado Plateau Appalachian Mountains Globally, they’re found in every continent in alpine regions, deserts, and disturbed lands.
Can They Help Us Solve Global or Regional Problems? <ul><li>They may help restore the Blue Lupine and therefore the Frosted Elfin populations in the Rome Sand Plains. </li></ul><ul><li>It’s possible that they may cool surroundings through albedo, thereby counteracting global warming. </li></ul><ul><li>They can improve the hydrologic cycle in disturbed ecosystems. </li></ul><ul><li>They can potentially aid in efforts to reverse desertification. </li></ul>Blue Lupine Frosted Elfin butterfly
The Challenge of Desertification Once vegetated, this landscape was victim to desertification. Source: UN’s FAO “ Nigeria, Africa’s most populous country, is losing 351,000 hectares of rangeland and cropland to desertification each year.” “… over the last half-century, some 24,000 villages in northern and western China have been entirely or partly abandoned as a result of being overrun by drifting sand. ” “ In Brazil, where some 58 million hectares of land are affected, economic losses from desertification are estimated at $300 million per year, much of it concentrated in the country’s northeast…” -- Lester R. Brown, Earth Policy Institute
Rome Sand Plains The Rome Sand Plains are remnants of the eastern shallow areas of glacial Lake Iroquois, which contained large volumes of sand. This pine barrens is one of only 20 inland pine barrens worldwide.
Objectives of the Study <ul><li>To identify the macroscopic species that make up the biological soil crust at the Rome Sand Plains. </li></ul><ul><li>To determine the water absorption capacity of the biological soil crust under different environmental conditions. </li></ul><ul><li>To measure the crust’s contribution to soil moisture. </li></ul><ul><li>To measure soil stability due to biological soil crust cover. </li></ul><ul><li>To observe and measure the crust’s effect on surface microclimate and surrounding air temperature. </li></ul><ul><li>To measure the rate of recovery under certain conditions. </li></ul><ul><li>To estimate the total surface area covered with biological soil crust in the Rome Sand Plains and map the area. </li></ul>
Macroscopic Components of the Biological Soil Crust 3cm Ladder Lichen Reindeer Moss Burned Ground Moss Cyanobacteria British Soldier Common Species Common Name Scientific Name Common Species Burned Ground Moss Ceratodon purpureus Reindeer Moss (lichen) Cladonia rangiferina Ladder Lichen Cladonia verticillata British Soldiers Cladonia cristatella Uncommon Species Reindeer Lichen Cladonia arbuscula Powdered Trumpet Cladonia fimbriata Yellow Moss Homalothecium fulgescens Polytrichum strictum Haircup Moss
Objective: To determine the water absorption capacity of the biological soil crust under different environmental conditions. <ul><li>Methods: </li></ul><ul><li>Exactly 75 samples of biological soil crust were collected using clear tubes. </li></ul><ul><li>Samples were dried or moistened to field capacity. </li></ul><ul><li>Samples were placed under various environmental conditions using a chamber with controlled humidity and temperature and weighed regularly. </li></ul>
Clearly, sand covered with bushy lichens gains much more water than moss or no covers. Troughs represent daytime hours, when lichens lose water to evaporation and the soil.
Again , lichens absorb more water than mosses and sand. All three cover types stabilize after absorbing some water. Proper light and natural cycles would allow absorbance to continue. High Humidity, Lower Temperature
The biological soil crust from this temperate region cannot absorb water under hyper-arid conditions. However, since these organisms are genetically adapted to a temperate region, we cannot tell whether biological soil crusts in semi-arid areas would also fail to absorb water.
The soil with lichen cover retains the most moisture. These results indicate that for every 0.0024m ² of crust cover, about 1 to 2 grams of water will be absorbed every day, a portion of which is made available to vascular plants. Rain Period
Objective: To measure the crust’s contribution to soil moisture. <ul><li>Method: </li></ul><ul><li>Exactly 6 large sand samples were collected from the sand dune and biological soil crusts. </li></ul><ul><li>Samples were weighed, dried, and re-weighed to determine moisture content. </li></ul><ul><li>For moisture contribution, samples were dried and allowed to absorb water. Components were then separated and dried. </li></ul><ul><li>Samples were weighed at each step. </li></ul>
Most of the absorbed water ends up in the sand, while a large portion evaporates from the organisms.
These results show that the contribution to soil moisture increases as biological soil crust diversity increases.
Objective: To measure soil stability due to biological soil crust cover. <ul><li>Method: </li></ul><ul><li>A soil penetrometer was used to measure the stability of the sand at different locations. </li></ul><ul><li>The device was inserted one-quarter of an inch into the soil. </li></ul>
Sand covered with biological soil crust is much more stable than sand with no cover. Sand from the trail is somewhat stable because it compacts as hikers step on it.
Other Methods <ul><li>For surface microclimate and albedo effect verification: </li></ul><ul><li>TidBit devices were placed underground inside air-filled tubes in four locations: below bare sand and below crust-covered sand. Two others were attached to trees to measure surrounding air temperature. </li></ul><ul><li>For recovery rate under certain conditions: </li></ul><ul><li>Disturbed spots created from sampling were treated with four conditions: fertilizer, inoculum, combination, and control. </li></ul>*The TidBit devices were recently collected, and the crust is not expected to recover until next Spring. Area was estimated at more than 3900 m ² using a measuring tape.
Source: UN Environment Programme Implications for Regions in High Risk of Desertification 1200-3000 Tectona grandis (Asia) 1000-2000 Calophyllum calaba (Caribbean) 1500-2500 Catalpa longissima (Caribbean) 600-800 African Blackwood (Southwest Africa) 1500 Ceiba pentandra (C. and South America) 800-1700 Swietenia mahogani (South America) 750 Acacia farnesiana (Europe) Low to Moderate Conifers Requirement (mm per year) Plant Water Requirements of Key Plant Conservation Species
Conclusion/Summary <ul><li>There are eight species within the biological soil crust, three of which are mosses. The others are lichens. </li></ul><ul><li>Due to a lack of epidermal tissue, the species within the crust do not help retain moisture in the top 1cm of the soil. Instead, they lose water through diffusion and cluster soil particles, making them retain more moisture. </li></ul><ul><li>On average, sand underneath the biological soil crust absorbed more water than sand from the trail or the sand dune. </li></ul><ul><li>Most of the water lost by the organisms during the day is due to evaporation. </li></ul><ul><li>Lichens absorb the most water under any temperate conditions. </li></ul><ul><li>Soil covered with biological soil crust is much more stable than soil with no cover. </li></ul>
Future and Suggested Work <ul><li>In the Fall, I will statistically analyze the data, continue monitoring the recovery experiment, present my work at various places, and finish the study report. </li></ul><ul><li>In December/January, as well as the summer of 2007, I will test the effectiveness of biological soil crusts at aiding to reforest native trees in arid lands in the Dominican Republic. </li></ul><ul><li>I suggest that the CBFS looks at the influence the biological soil crust has on vascular plants living there, especially Blue Lupine. </li></ul><ul><li>I suggest that the next study analyzes the differences between nitrogen content in sand dunes and crust-covered soils. This study should look at the lichens and cyanobacteria that fix nitrogen. </li></ul><ul><li>Finally, I strongly urge interested researchers to look at the influence biological soil crusts have on different types of soils, especially nutrient-poor soil. Studies should focus on the implications for reversing desertification in high-risk areas of the world. </li></ul>
Acknowledgements <ul><li>I would like to thank my advisor, Dr. Rebecca Schneider, for supervising my work, providing needed materials, and helping me in almost every section of the study. </li></ul><ul><li>Brian Young and Bill Thelen were extremely helpful along the way, and so I’d like to thank them as well. </li></ul><ul><li>Dr. William Pfitsch from Hamilton College and Pat Whalen from NYDEC are well appreciated for allowing me to collect samples in the Blue Lupine study area. </li></ul><ul><li>Finally, I would like to thank Dr. Ed Mills and the entire CBFS staff, including interns, for all their friendly support and guidance in using the facilities. </li></ul>
Remember… For more information about biological soil crusts, visit: www.soilcrust.org Visit www.stopglobalwarming.org to stop global warming and reverse desertification.