Vegetation in an area may determine its usable water supply, ecologists find
Ohia Forest Haleakala Maui Click Here for Larger ImageEcologists have discovered that timber plantations in Hawaii use more than twice the amount of water to grow as native forests use. Especially for island ecosystems, these findings suggest that land management decisions can place ecosystems – and the people who depend on them – at high risk for water shortages.
"Scientists used to think that forests in same environments use water in the same way," says Lawren Sack of The University of California at Los Angeles, who coauthored the study with graduate student Aurora Kagawa in the September issue of the ESA journal Ecological Applications. "Our work shows that this is not the case. We need to know the water budget of our landscape, from gardens to forests to parks, because water is expensive."
Although forests like these Hawaiian timber plantations can be valuable for their contributions to human society, such as fiber, fuel and carbon sequestration, they are dominated by non-native vegetation.
Kagawa, Sack and their colleagues compared the water use of trees in native forests, composed mostly of native ohia trees, with water use in timber plantations containing exotic eucalyptus and tropical ash. The team inserted heated and unheated probes into the trees’ trunks and monitored the temperature differences between the two as sap flowed past them. This technique allowed them to determine the rate of sap flow through the tree. A faster flow rate means that the tree is using more water.
August 6, 2009
Federal lawmakers have designated more than $16 million in federal funding to improve Hawaii’s agriculture. A large part, more than $11 million, will go to research — that includes addressing Hawaii’s farming struggles, our floriculture industry and tropical fish population.
$106,000 will fund the Hawaii Plant Materials Center located on Moloka’i. The center enables the Kaho’olawe Island Reserve Commission to reintroduce native plant species in their efforts to control invasive plants and erosion on the island of Kaho’olawe. They will also receive a portion of $376,000 to stimulate agricultural development and conservation at the local level.
Hawaii fruit growers harvested 435.2 million pounds of fruit for fresh and processed utilization in 2006, an 11 percent decline from the previous year, according to the USDA, NASS, Hawaii Field Office. Total value fell 3 percent to $101.7 million, with guava, lemon, papaya, pineapple, and the tropical specialty group recording declines in value of sales. Fruit acreage totaled 19,740 acres, a 2 percent decrease from 2005. Harvested area decreased 6 percent to 4,090 acres. Almost continuous rainfall from late February through March contributed to losses in some crops due to soil erosion, flooding, disease outbreaks, and fruit and tree losses. The lengthy rainy period slowed fruit maturation in some crops.
Pineapple, still Hawaii?s largest fruit commodity, represented 70 percent of total fruit acreage and 74 percent of the total fruit value. Total utilized pineapple production fell 11 percent to 376 million pounds. Since records were kept by the Hawaii Field Office, 2006 was the first year fresh market utilization outweighed processed utilization. Also establishing a record was the average farm price. In late 2006, operations ended prematurely for one major company which had previously announced their phase-out of pineapple production.
The state?s papaya producers devoted 2,095 acres toward papaya production, a decrease of 13 percent from the previous year. Harvested area totaled 1,530 acres, 3 percent more than 2005. Papaya output declined 13 percent to 28.7 million pounds while value of sales dropped 2 percent to $11.0 million.
Total banana acreage rose 5 percent in 2006 while harvested acreage increased 2 percent to 1,000 acres. Utilized production was pegged at 20.0 million pounds, 4 percent less than 2005. However, higher average prices helped push total value of sales to $9.8 million, 7 percent higher than the previous year.
Total guava production area declined 14 percent to 575 acres in 2006 while area harvested declined 41 percent to 365 acres. Value of sales declined 7 percent to $1.1 million. Hawaii?s guavas, which are mainly for the processed market, recorded a 2 percent increase in price. However, this was not enough to offset the 9 percent lower output.
Area devoted to tropical specialty fruit totaled 1,240 acres in 2006, 2 percent less than 2005. Area harvested totaled 690 acres, 5 percent lower than the previous year. Hawaii?s growers of tropical specialty fruit produced and sold an estimated 1.45 million pounds of fruit in 2006, relatively unchanged from 2005. Compared with 2005, higher output was registered for longan, lychee, mango, and persimmon. Value of sales was pegged at $2.6 million in 2006, 4 percent lower than 2005.
“HAWAII PAPAYAS” reports are available on our website and also PRINTED monthly. Subscriptions for PRINTED copies are free to those persons who report agricultural data to NASS (upon request) and available for $4 per year to all others.
JULY FRESH PAPAYA HIGHER
Hawaii fresh papaya utilization is estimated at 2.4 million pounds for July 2007, up 16 percent from last month and 40 percent higher than the same month a year ago. Year-to-date sales for the first seven months of 2007 posted 15.4 million pounds, 5 percent above the comparable period in 2006.
Warm summer weather continued in July, encouraging flowering and fruit set. Tropical Depression Cosme and a weak shear line brought welcomed showers to the State. Normal farming activities were underway. Harvesting was steady. Growers were preparing fallowed fields for new plantings. Wild pig damage and Papaya Ringspot Virus were still affecting some orchards.
Papaya growers are expected to receive an estimated 47.0 cents per pound for fresh fruit in July, 10 percent (5.0 cents) lower than June, but unchanged from a year ago.
2006 Papaya Output Down
In 2006, papaya output totaled 28.7 million pounds, down 13 percent from 2005 and falling for the fifth consecutive year. Weather for 2006 had a mixture of wet and dry conditions. Continuous rain fell during mid-February until early April causing soil erosion, flooding, disease outbreaks, and fruit and tree losses in orchards across the State. It also delayed normal field routines including planting schedules.
The biotechnology variety Rainbow made up 58 percent of total acres in 2006, up 9 percent from 2005. Rainbow is resistant to Papaya Ringspot Virus (PRV), a virus that devastated the Hawaii papaya industry from 1993 to 1999. The Kapoho variety was the standard for the papaya industry for many years; however, Kapoho is susceptible to PRV. Yields of Rainbow are higher during the first year of harvest compared to the Kapoho variety. In the second year of harvest, yields for Rainbow are comparable to the Kapoho variety. Routine field inspections and rogueing of infected trees kept losses to PRV light. The Kapoho variety comprised 25 percent of total acreage compared to 30 percent the previous year. Annual August surveys since year 2000 show Rainbow and Kapoho have been the major two varieties.
The State’s in crop papaya acreage totaled 2,095 down 13 percent from the previous year. Harvested acreage rose 3 percent from 2005 to 1,530 acres, up for the second year.
In 2006, the number of farms totaled 168, declining 19 percent from the 2005.
Hawaii County continues to lead with papaya production and accounting for the majority of the State’s total.
Value of utilization (fresh and processed) for 2006 was pegged at $11.0 million, 2 percent below 2005. Papaya price of 38.5 cents per pound increased 4.3 cents above last year average.
U.S. Papaya Imports Higher
Fresh papaya imports from foreign sources into the United States totaled 291.4 million pounds in 2006, up 14 percent from the previous year, according to the Department of Commerce. Mexico accounted for 201.0 million pounds or 69 percent of the total. Imports from Belize have steadily increased and contributed 26 percent of the total imports in 2006.
Total imports by type for 2006 increased 14 percent from 2005 to 308.6 million pounds due to more fresh papayas. Fresh imports continued to account for the majority or 94 percent of total imports.
World Papaya Production Up 2 Percent
World papaya production totaled 14.9 billion pounds in 2006, up 2 percent from a year ago, according to the Food and Agriculture Organization.
Brazil remained the top producer of papayas growing 3.5 billion pounds. Rounding out the top five producers world wide are Nigeria with 1.8 billion pounds, Mexico with 1.8 billion pounds, India with 1.7 billion pounds, and Indonesia with 1.4 billion pounds.
