Last goats living on UK coastal site culled by National Trust / National Trust creates living gene bank of endangered native black poplar / National Trust paint archive promises to bring secrets to light / National Trust members 'consider leaving' over changes at popular country house / National Trust project to plant almost half a million trees this winter / National Trust announces plans to address UK's mental health crisis / National Trust to restore nature across area bigger than Greater London / National Trust warning as charity issues urgent plan to tackle dwindling wildlife levels / National Trust warns UK's most precious heritage at risk from extreme weather