A system and method are provided for promoting vegetation growth on a steeply sloping surface. The light delivery system functions to illuminate a region of a sample and generate a non-linear response in a spatial region smaller than that associated with a Gaussian beam having a width comparable to the width of the embedded Gaussian beam. The welding rib provided on the developing frame is disposed so as to be located between the plurality of reinforcing members as viewed from a direction intersecting with the surface and the back, and the developer container and the developing frame are connected together by the ultrasonic welding. The system monitors the average CV-EDP value over a predetermined interval, and dynamically adjusts the LRL setting responsive to the detection of a first or a second predetermined event based on the average CV-EDP value. The end of the lever can contain a conical opening mating with the conical pivot pin on the gate mechanism.