Key TakeawaysDollar Tree reported second-quarter earnings below what analysts' expectations Wednesday, with profits falling year-over-year.Executives said the company is facing "immense pressures" from the economic environment.The comments are similar to those from executives at Dollar General, who last week said they saw a "financially constrained" consumer. Dollar Tree (DLTR) shares tumbled in premarket trading Wednesday after the discount retailer reported another earnings miss and said it is facing "imm ...