The forests of Uttarakhand, Kullu Valley in Himachal Pradesh, and Dzukou Valley in Nagaland and Manipur were in the news due to forest fires. Forest fires are a major concern as they can cause significant ecological damage and pose a threat to wildlife, vegetation, and human settlements in and around forests.

Option 1: Deforestation refers to the act of clearing or destroying forests. While deforestation is indeed a serious environmental issue, it is not specifically related to the news about the forests in these regions.

Option 3: Poaching of wild animals involves the illegal hunting or capturing of wildlife. Although poaching is a severe issue, the news about the forests in these regions did not specifically mention it as the reason.

Option 4: Illegal mining refers to mining activities that are conducted without proper permits or in violation of regulations. There was no mention of illegal mining as the reason for the news about these forests.

Therefore, the correct answer is option 2: forest fires. It is important to note that this information is based on the given question, and if there are any additional factors or developments not mentioned in the question, the answer may vary.