Sony NEX-3NL or Nikon D3100?

Hi! So I'm planning on buying a camera and am torn between these two. I would be using the camera for portraits, travelling, landscapes, nature and such. I would appreciate any helpful comments from people who know more about this area than me, so please help.

The compactness of the Sony makes it attractive for travel. I think the absence of a hotshoe is going to make it less well suited to portraits, and the limited selection of lenses is going to make it less well suited to nature.

Trying to use an LCD outdoors in bright weather for travel photography is not a good experience and trying to hold a camera with a long lens steady for nature photography at arms length while looking at an LCD doesn't lend itself to stable shots. I would go for a proper viewfinder every time. If you want a decent flash or remote trigger for lighting portraits then sooner or later you will want a hotshoe. The Nikon wins hands down for usability.

Attempting to shoot using a camera that has NO viewfinder will cause terrible blur caused when attempting to shoot using a telephoto lens, something you need if you intend to shoot wildlife (nature)

Holding any camera at arm's length is going to cause camera movement and that will certainly produce poor images

The Nikon, on the other hand, uses an optical viewfinder and you will be able to hold the camera up to your eye and hold the camera with two hands. This is the next best thing to using a tripod and has been the preferred (and only) way to shoot a SLR, rangefinder or dSLR for many decades.

Martin and Thankyoumaskedman have given you some excellent information.