Patterns and controls of ecosystem function in longleaf pine - wiregrass savannas. I. Aboveground net primary productivity

1999 ◽  
Vol 29 (6) ◽  
pp. 743-751 ◽  
Author(s):  
Robert J Mitchell ◽  
L Katherine Kirkman ◽  
Stephen D Pecot ◽  
Carlos A Wilson ◽  
Brian J Palik ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Primary Productivity ◽  
N Mineralization ◽  
Environmental Gradient ◽  
Net Primary Productivity ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
Individual Species ◽  
Aboveground Net Primary Productivity ◽  
Resource Limitations

Longleaf pine - wiregrass (Pinus palustris Mill. - Aristida stricta Michx.) woodlands occupy sites ranging from deep, xeric sandhills to the edge of wetlands in the southeastern United States. Aboveground net primary productivity (ANPP) of the overstory and understory were determined for three replicate sites of three site types (xeric, intermediate, and wet-mesic) that span a wide environmental gradient. In addition, soil moisture (at 30 and 90 cm) and N mineralization (in situ buried bag incubations) were measured through an annual cycle. Longleaf pine - wiregrass ecosystems varied by nearly twofold in ANPP across complex gradients. Overstory and understory and total (overstory and understory) ANPP were positively correlated to soil moisture at 30 and 90 cm. The proportion of understory ANPP relative to the total ANPP did not increase across the environmental gradient as predicted by hypotheses that invoke niche differentiation in rooting habits of grasses and trees. Contrary to expectations, cumulative net N mineralization was negatively related to soil moisture. All ANPP estimates were significantly and negatively related to cumulative N-mineralization. Further work is needed to explore the mechanisms by which soil moisture regulates productivity across space, time, and for individual species. Additional experimentation through resource addition would allow for investigations into multiple resource limitations and how resource limitations vary depending on gradient position.

Water table depth affects productivity, water use, and the response to nitrogen addition in a savanna system

2008 ◽  
Vol 38 (8) ◽  
pp. 2118-2127 ◽  
Author(s):  
Chelcy R. Ford ◽  
Robert J. Mitchell ◽  
Robert O. Teskey
Keyword(s):  
Water Use ◽  
Water Table ◽  
Net Primary Productivity ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
High Water ◽  
Life Forms ◽  
Water Table Depth ◽  
N Addition ◽  
Aboveground Net Primary Productivity

We investigated annual aboveground net primary productivity (ANPP) and transpiration (E) of the dominant plant life forms, longleaf pine (Pinus palustris Mill.) trees and wiregrass (Aristida stricta Michx.), in a fire-maintained savanna. Experimental plots spanned a natural hydrologic gradient (xeric and mesic site types) mediated by soil moisture (θ) and water table depth (WTD), and received additions of either 0 or 100 kg N·ha–1·year–1. Low rates of ANPP (1.3–2.2 Mg·ha–1) and annual E (108–380 mm) were observed in these communities. WTD and N addition explained 95% of the variation in community ANPP, whereas site type and WTD explained 83% of variation in community E. Between tree and grass life forms, longleaf pine ANPP was more coupled to WTD than wiregrass. For any given leaf area supported, ANPP of longleaf pine increased linearly with increasing water use and decreasing WTD. The longleaf pine ANPP response to N addition was greater in sites with high water use compared with those with low water use, indicating that this savanna system is colimited by nutrient and water availability and that water table depth plays a role in regulating savanna productivity.

Patterns and controls of ecosystem function in longleaf pine - wiregrass savannas. II. Nitrogen dynamics

1999 ◽  
Vol 29 (6) ◽  
pp. 752-760 ◽  
Author(s):  
Carlos A Wilson ◽  
Robert J Mitchell ◽  
Joseph J Hendricks ◽  
Lindsay R Boring
Keyword(s):  
Soil Moisture ◽  
N Mineralization ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
First Year ◽  
N Availability ◽  
Net N Mineralization ◽  
Ecological Gradient ◽  
N Losses ◽  
In Fire

The productivity of many temperate forests is nitrogen limited. Controls on N availability are particularly important in fire-maintained ecosystems such as longleaf pine - wiregrass (Pinus palustris Mill. - Aristida stricta Michx.) forests of the Coastal Plain of the southeastern United States, where periodic burning can result in substantial N losses. This study quantifies variation in net N mineralization across a complex ecological gradient for longleaf pine - wiregrass forests, from dry sandhills to wet-mesic sites adjacent to wetlands, for the first year after burning. Net N mineralization was consistently higher for the xeric site and declined as soil moisture status increased. Higher N availability was primarily due to higher rates of net nitrification in these plots, suggesting possible substrate-induced influences. Temperature was positively related to net N mineralization, while percent soil moisture was inversely correlated to net N mineralization. The greater N availability on dry sites may reflect greater quality organic matter inputs resulting from a significant hardwood (Quercus laevis Walt. predominately) component, and (or) it may reflect microclimate differences (warmer soil) that accelerate decomposition of detritus in soil.

scholarly journals A Comparison of the Attributes of Pine Straw from Southern Pine Species

2021 ◽  
Vol 39 (3) ◽  
pp. 115-122
Author(s):  
Zachary Singh ◽  
Adam Maggard ◽  
Rebecca Barlow ◽  
John Kush
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Properties ◽  
Soil Nutrients ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Weed Growth ◽  
Pine Straw

Abstract Longleaf pine (Pinus palustris Mill.), and slash pine (Pinus elliottii Engelm.) are two southern pine species that are popular for producing pine straw for landscaping. The objective of this research was to determine the response of soil properties and weed growth to the application of pine straw. Longleaf pine, slash pine, and two non-mulched controls (with and without chemical weed control) were tested. Volumetric soil water content, soil nutrients, soil temperature, weed biomass, and seedling growth were measured. Compared to non-mulched controls, both longleaf and slash pine plots had a greater soil moisture during extended periods without rainfall in the full sun environment. When soil temperatures increased, mulched plots had lower soil temperature relative to non-mulched plots. Soil pH and soil nutrients were generally similar between pine straw types with few significant differences in measured variables. Both pine straw treatments reduced weed growth and longleaf pine maintained a greater straw depth over the study period compared to slash pine, but no differences were observed for decomposition. These results indicate that longleaf pine straw and slash pine straw perform equally as well in terms of increasing soil moisture, moderating soil temperature, and reducing weed growth compared to not using mulch. Index words: Pinus elliottii, Pinus palustris, organic mulch, soil properties, landscaping. Species used in this study: Shumard oak, Quercus shumardii Buckl., Eastern redbud, Cercis canadensis L.

scholarly journals Impact of Extreme Weather Events on Aboveground Net Primary Productivity and Sheep Production in the Magellan Region, Southernmost Chilean Patagonia

Geosciences ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 318
Author(s):  
Pamela Soto-Rogel ◽  
Juan-Carlos Aravena ◽  
Wolfgang Jens-Henrik Meier ◽  
Pamela Gross ◽  
Claudio Pérez ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Maximum Temperature ◽  
Aboveground Net Primary Productivity ◽  
Weather Events ◽  
Chilean Patagonia ◽  
Magellan Region ◽  
Sheep Production

Spatio-temporal patterns of climatic variability have effects on the environmental conditions of a given land territory and consequently determine the evolution of its productive activities. One of the most direct ways to evaluate this relationship is to measure the condition of the vegetation cover and land-use information. In southernmost South America there is a limited number of long-term studies on these matters, an incomplete network of weather stations and almost no database on ecosystems productivity. In the present work, we characterized the climate variability of the Magellan Region, southernmost Chilean Patagonia, for the last 34 years, studying key variables associated with one of its main economic sectors, sheep production, and evaluating the effect of extreme weather events on ecosystem productivity and sheep production. Our results show a marked multi-decadal character of the climatic variables, with a trend to more arid conditions for the last 8 years, together with an increase in the frequency of extreme weather events. Significant percentages of aboveground net primary productivity (ANPP) variance is explained by high precipitation, mesic temperatures, and low evapotranspiration. These conditions are, however, spatially distributed in the transition zone between deciduous forests and steppe and do not represent a general pattern for the entire region. Strong precipitation and wind velocity negatively affect lamb survival, while temperature and ANPP are positively correlated. The impact of extreme weather events on ANP and sheep production (SP) was in most of the cases significantly negative, with the exception of maximum temperature that correlated with an increase of ANPP, and droughts that showed a non-significant negative trend in ANPP. The examination of these relationships is urgent under the current scenario of climate change with the acceleration of the environmental trends here detected.

scholarly journals Aboveground Net Primary Productivity in a Riparian Wetland Following Restoration of Hydrology

Biology ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 10
Author(s):  
Melissa Koontz ◽  
Christopher Lundberg ◽  
Robert Lane ◽  
John Day ◽  
Reza Pezeshki
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Aboveground Net Primary Productivity ◽  
Riparian Wetland
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