The department may require an applicant to whom a permit has been issued to post a blanket bond covering all work to be done pursuant to all permits issued to an applicant, to insure and protect the Commonwealth against loss or damage to trees for vegetation for which remedial action has not been approved or deemed to be approved and occasioned by pruning, trimming, relocation or removal of trees or vegetation and to require the applicant to indemnify the department for the replacement cost of any such trees or vegetation so damaged or destroyed. The amount of the bond shall be determined by the department and shall bear a reasonable relation to the nature of the work being done by the applicant.