Showing 251 – 260 of 395 resources
Maple syrup is a natural product free of artificial coloring or other additives. Regardless, some publications mention that maple syrup may contain sulfites. In this study, which is conducted by Center ACER in collaboration with UVM Proctor Maple Research Center, direct measurements of sulfites concentration in maple syrup samples collected during 2011 and 2012 were made.
The allocation of nonstructural carbon (NSC) to growth, metabolism and storage remains poorly understood, but is critical for the prediction of stress tolerance and mortality. We used the radiocarbon (14C) Ôbomb spikeÕ as a tracer of substrate and age of carbon in stemwood NSC, CO2 emitted by stems, tree ring cellulose and stump sprouts regenerated followingharvesting in mature red maple trees. We addressed the following questions: which factors influence the age of stemwood NSC?; to what extent is stored vs new NSC used for metabolism and growth?; and, is older, stored NSC available for use?
Studies currently underway at the University of Vermont Proctor Maple Research Center (PMRC) are examining the effects of accumulating internal taphole damage on the ability to support future tapping, as well as related subjects such as the effects high vacuum sap extraction might have on tree growth, all with the goal of developing new sustainable tapping guidelines. However, along with focusing on the possible negative effects of tapping and sap extraction, it is important to examine how certain practices might lead to greater sap yields.
In 2012 a variety of spout and tubing cleaning and replacement options were tested to determine the extent of sap yield changes. These tests were done at the Cornell Arnot Research Forest.
The goal of this work was to investigate the chemical composition of the scale that is deposited on maple evaporator surfaces during sap processing. Knowing the chemical composition of scale produced in modern equipment and how it compares to previously published values for loose sugar sand may aid in understanding how best to remove these unwanted deposits.
Nonstructural carbohydrate reserves support tree metabolism and growth when current photosynthates are insufficient, offering resilience in times of stress. We monitored stemwood nonstructural carbohydrate (starch and sugars) concentrations of the dominant tree species at three sites in the northeastern United States. We estimated the mean age of the starch and sugars in a subset of trees using the radiocarbon (14C) bomb spike. With these data, we then tested different carbon (C) allocation schemes in a process-based model of forest C cycling.
A wide variety of cleaning techniques are currently used in the maple industry, including rinsing the system with pressurized air and water, or attempts to sanitize with chemical solutions such as peroxide, bleach, or alcohol. However, the effectiveness of these cleaning techniques in reducing microbial populations and increasing annual sap yield is often questionable.
An important part of beginning or improving the tubing system in a maple enterprise is to have a good estimate of just how much the project will cost. Though there are many variables in installing a new or replacing an old system the cost of materials is predictable. Two factors allow you to make a reasonable estimate of what a sap collection system will cost in materials. The first is the number of taps per acre. The second is the density of trees.
Due to projected increases in winter air temperatures in the northeastern USA over the next 100 years, the snowpack is expected to decrease in depth and duration, thereby increasing soil exposure to freezing air temperatures. To evaluate the potential physiological responses of sugar maple (Acer saccharum Marsh.) to a reduced snowpack, we measured root injury, foliar cation and carbohydrate concentrations, woody shoot carbohydrate levels, and terminal woody shoot lengths of trees in a snow manipulation experiment in New Hampshire, USA. Snow was removed from treatment plots for the first 6 weeks of winter for two consecutive years, resulting in lower soil temperatures to a depth of 50 cm for both winters compared to reference plots with an undisturbed snowpack.
Gravity tubing systems are widely used in many small to mid-sized operations throughout the maple region. This article summarizes the past 3 years of my research on gravity tubing, or tubing without a vacuum pump.