If you use a rowing machine alot. and by alot i mean about 10 kilometers a day you will loose fat from almost everywhere. but rowing machines also tend to put on muscle.
and whatever you do, if you want to flatten out your stomache crunches are the worst thing to do. they give you abs like the guys in 300. in other words they build the muscle out.
planks are the key to just tucking in your stomach without looking like a spartan

you cannot spot reduce fat.

The only way to trim down your tummy is to reduce the fat all over your body. Stick to a healthy diet, and exercise! Rowing is a great exercise that can help you develop your chest, arms, and back, as well as help with your core. I would suggest doing some cardio as well.

Anything cardio that will help your body burn fat is going to help!
Rowing machines work fine!
Just remember:
30-45minutes of cardio 3-4 times a week and those pounds will shed!!!

Good luck!

You cannot simply lose fat from just one area of your body. Your extra weight, fat, is a collective, and must be lost as a collective in proportion. Will Rowing help you lose weight and burn calories? Yes. Will it snipe out that area of fat? No.

I highly suggest taking up jogging and other weightlifting aswell, if you want to lose some weight.

I think Rowers help your Arms more then your Tummy
. just do Crunches and Jog every morning and while you jog **or walk or Run depending on the shape you are in atm** **** in your gut while your jogging and it well help tighten it up