The plots in experiment E052 are enclosed by a fence to
exclude mammalian herbivores. Galvanized welded-wire hardware cloth with 6mm
x 6mm openings was buried to a depth of 84cm. Additional hardware cloth
extends 60cm above the ground, and poultry netting extends to 1.8m above the
ground.
Fertilization
Fertilizer is mixed and spread by hand twice a year,
once in early May and once in late June. Each plot gets the fertilizer
mixture specified by its fertilizer treatment code. For a list of fertilizer
treatments for each plot, see file trmte52.
Mammal Trapping
Pocket gophers are trapped out of the fields as soon
as they appear. Gopher mounds are then removed and vegetation is unburied.
Rototilling
Rototilling is done in April. Each plot receives the
amount of rototilling it should get according to the disturbance treatment
each plot is assigned. For a list of disturbance treatments for each plot,
see file trmte52.
Neighbor Exclusion
1990: The no neighbors treatment was imposed by
severing all roots at the perimeter of a subplot to a depth of 15cm once each
sample period. All plants in the subplots were sprayed with a systemic,
rapidly decomposing herbicide (Roundup). Any resprouting neighbor biomass was
severed at the soil surface and removed by hand. Transplants were grown with
only the roots of neighbors by using plastic netting to pull back the shoots
(50x50cm;mesh:1x2cm) was fastened to the soil surface at the center of the
subplot using four steel pins each 8cm long. The center portion (5x5cm) of
the net was cut out to allow transplanting. The outer corners of the net were
held 10cm above the soil using pins 20cm long. The all neighbors treatment
comprised a transplant grown in the center of a 50x50cm subplot containing the
existing, undisturbed vegetation of the plot. 1991:The no neighbor treatment
was imposed by driving a tube 10cm deep and 11cm in diameter into the soil and
killing all neighbor material inside with Roundup. Each tube was surrounded
by garden netting (50 x50cm) to ensure that transplants in no neighbor
treatments received an equal and constant amount of light. Transplants in all
neighbor treatments also had tubes installed around them in order to make a
comparable amount of environmental space available to transplants in both the
neighbor and no neighbor treatments.
Additional notes
On May 5, 1995, a wildfire burned all of the plots
in experiment 52 in field B.